mocetinostat and Arthritis--Rheumatoid

Neutrophil extracellular traps (NETs) are a neutrophil defensive mechanism where chromatin is expelled together with antimicrobial proteins in response to a number of stimuli. Even though beneficial in many cases, their dysfunction has been implicated in many diseases, such as rheumatoid arthritis and cancer. Accurate quantification of NETs is of utmost importance for correctly studying their role in various diseases, especially when considering them as therapeutic targets. Unfortunately, NET quantification has a number of limitations. However, recent developments in computational methodologies for quantifying NETs have vastly improved the ability to study NETs. Methods range from using ImageJ to user friendly applications and to more sophisticated machine-learning approaches. These various methods are reviewed and discussed in this review.

Topics: Animals; Arthritis, Rheumatoid; Computational Biology; Diagnostic Imaging; Extracellular Traps; Humans; Leukocyte Elastase; Machine Learning; Neoplasms; Neutrophils; Peroxidase; Software

Inflammation is an initial response of the body to a harmful stimuli and it is achieved by the increased movement of leukocytes (especially granulocytes) from blood into injured tissues. It is required for healing wounds and infections. Despite their indispensable role in microbial killing, the inflammation reactions may also cause diseases to a host such as hay fever, atherosclerosis, and rheumatoid arthritis. The enzymes and oxidizing species released during the inflammatory process can cause damages to the host tissues which lead to inflammatory syndromes. The role of myeloperoxidase (MPO) in the inflammatory reactions is well documented. It contributes in killing the pathogens but it is also implicated in several inflammatory syndromes such as Parkinson's disease, Alzheimer's disease and atherosclerosis. Thus, this enzyme has attracted more attention of the scientists and it has become a target for drug designing. In the last decade, several reversible and irreversible MPO inhibitors were identified as very high potent inhibitors such as fluoroalkylindole, aromatic hydroxamic acid, thioxanthine and benzoic acid hydrazide derivatives. In this review, we tried to illustrate the MPO inhibitors and highlight their structure activity relationship (SAR). In this paper we also discussed the mechanism of the inhibitory effect of the most potent compounds.

Topics: Arthritis, Rheumatoid; Atherosclerosis; Chalcones; Drug Design; Enzyme Inhibitors; Flavonoids; Humans; Molecular Docking Simulation; Neurodegenerative Diseases; Peroxidase; Structure-Activity Relationship

Taurine (2-aminoethanesulfonic acid) is the most abundant free amino acid in humans and plays an important role in several essential biological processes such as bile acid conjugation, maintenance of calcium homeostasis, osmoregulation and membrane stabilization. Moreover, attenuation of apoptosis and its antioxidant activity seem to be crucial for the cytoprotective effects of taurine. Although these properties are not tissue specific, taurine reaches particularly high concentrations in tissues exposed to elevated levels of oxidants (e.g., inflammatory cells). It suggests that taurine may play an important role in inflammation associated with oxidative stress. Indeed, at the site of inflammation, taurine is known to react with and detoxify hypochlorous acid generated by the neutrophil myeloperoxidase (MPO)-halide system. This reaction results in the formation of less toxic taurine chloramine (TauCl). Both haloamines, TauCl and taurine bromamine (TauBr), the product of taurine reaction with hypobromous acid (HOBr), exert antimicrobial and anti-inflammatory properties. In contrast to a well-documented regulatory role of taurine and taurine haloamines (TauCl, TauBr) in acute inflammation, their role in the pathogenesis of inflammatory diseases is not clear. This review summarizes our current knowledge concerning the role of taurine, TauCl and TauBr in the pathogenesis of inflammatory diseases initiated or propagated by MPO-derived oxidants. The aim of this paper is to show links between inflammation, neutrophils, MPO, oxidative stress and taurine. We will discuss the possible contribution of taurine and taurine haloamines to the pathogenesis of inflammatory diseases, especially in the best studied example of rheumatoid arthritis.

Topics: Animals; Anti-Infective Agents; Apoptosis; Arthritis, Rheumatoid; Bile Acids and Salts; Calcium; Humans; Inflammation; Osmoregulation; Peroxidase; Taurine

Several cases of rheumatoid arthritis (RA) with myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-associated crescentic glomerulonephritis (CrGN) have been reported. However, its clinical characteristics are not clear.. We summarized 3 patients of concurrent RA and MPO-ANCA-associated CrGN, diagnosed in our hospital from 1992 to 2006, and compared their clinicopathological data with those of 10 MPO-ANCA-associated CrGN patients without RA in the same period.. All three RA patients were middle-aged or young adult women with 7-14 years of RA history. The initial clinical symptom was microhematuria, and mean duration from hematuria onset to histological confirmation of CrGN was 17 months. At renal biopsy, serum creatinine concentration (sCr) was modestly elevated, with the mean value of 3.4 mg/dl. Crescents were detected in 30% of glomeruli, whereas advanced glomerular sclerosis, tubular atrophy, and interstitial fibrosis were also observed. In comparison with patients without RA, patients with RA were significantly younger and showed a longer duration from the onset to histological confirmation of CrGN. Serum creatinine concentration at referral was significantly lower; however, estimated glomerular filtration rate (eGFR) was comparable. The Birmingham Vasculitis Activity Score and the Disease Extent Index were significantly lower, and pathological examination showed less crescent formation and a tendency to advanced glomerular sclerosis in patients with RA.. In patients with RA, MPO-ANCA-associated CrGN appeared to develop at younger ages and often showed a slowly progressive deterioration of the renal function with slight extrarenal manifestations. These smoldering clinical features may result in late referral from rheumatologists to nephrologists and therefore poor prognosis.

Topics: Adult; Age of Onset; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Biomarkers; Biopsy; Case-Control Studies; Creatinine; Disease Progression; Female; Glomerular Filtration Rate; Glomerulonephritis; Hematuria; Humans; Kidney; Middle Aged; Peroxidase; Prognosis; Proteinuria; Referral and Consultation; Retrospective Studies; Severity of Illness Index; Time Factors

Relationships between rheumatoid arthritis (RA) and the thyroid gland have been studied extensively for a long time. The studies of this problem have focused mainly on: (a) the functional and immune thyroid gland abnormalities in patients with previous history of RA, and (b) joint changes in patients with previous autoimmune thyroid diseases. Thyroid dysfunctions in RA patients are most often of autoimmune nature; they are accompanied by elevated thyroid autoantibody titers. The RA patients usually present with eu-, hypo- or hyperthyroid manifestations. The concurrent affection of joints and thyroid gland is related most probably to a genetic predisposition determined by the affiliation to a certain HLA type, most often HLA-DR. Joint abnormalities in thyroid gland disorders may be of different character (generally polyarthritis) and they are due to hypothyroidism. One possible explanation of the presence of two or more autoimmune diseases in one individual is microchimerism - the presence of a small number of fetal cells in the mother as well as maternal cells in the fetus. These data provide grounds for tests to be performed in all cases of RA so that thyroid autoantibodies and thyroid dysfunctions can be detected early and treated adequately.

Topics: Arthritis, Rheumatoid; Autoantibodies; Humans; Peroxidase; Thyroid Diseases; Thyroid Gland; Thyroiditis, Autoimmune

Anti-neutrophil cytoplasmic antibodies (ANCA) are mostly known as a useful diagnostic tool in patients with small-vessel vasculitides. With the accumulating knowledge of these autoantibodies, however, it becomes clear that the role of ANCA may not be only limited to a diagnosis of such disorders. The current review addresses, in addition to classical diagnostic associations, other diseases connected with ANCA positivity, both in adults and in children. The etiology of ANCA remains unknown, but still, the importance of both genetic and environmental factors is undoubted. The role of infection and chemicals in the etiology of ANCA-associated diseases is stressed in particular. A pathogenetic role of ANCA is suggested because of clinical observations based on the correlation of the vasculitis activity and the titer of ANCA. Many experiments show the effects of ANCA in various steps of an inflammatory process, particularly on leukocyte microbicidal activity and oxidative burst. Recent findings are analyzed in the experimental field and they are correlated with clinical significance.

Topics: Adult; Aged; Animals; Antibodies, Antineutrophil Cytoplasmic; Antimicrobial Cationic Peptides; Arthritis, Rheumatoid; Autoantigens; Autoimmune Diseases; Blood Proteins; Cell Adhesion Molecules; Child; Colitis, Ulcerative; Cystic Fibrosis; Cytokines; Humans; Infections; Membrane Proteins; Mice; Middle Aged; Myeloblastin; Neutrophils; Peroxidase; Respiratory Burst; Serine Endopeptidases; Silicosis; Vasculitis

AN IMPORTANT CLINICAL TOOL: A sensitive and specific marker allowing the diagnosis of rheumatoid arthritis, and even more importantly an early assessment of severity, would be a highly valuable clinical tool. Autoantibodies have been found to be quite useful in clinical practice for diagnosis and assessing prognosis. EARLY-STAGE RHEUMATOID ARTHRITIS: Ideally, the marker should be sensitive and specific when the first signs of the disease develop. To date, only the rheumatoid factor and anti-filaggrin antibodies (including anti-stratum comeum or "anti-keratin" and anti-perinuclear factors) have been used with sufficiently acceptable standards. IgM rheumatoid factors can be detected in about 80% of patients with rheumatoid arthritis but they lack specificity since they are also found in other auto-immune conditions (lupus, Sjögren's syndrome), in chronic infections, and in certain lymphoproliferative syndromes (with or without cryoglobulinemia). Anti-filaggrin antibodies are more specific (70 to 100% depending on the study) but can only be detected in 30 to 50% of the patients. High titers of rheumatoid factors (IgM and/or IgA) and anti-filiggrin antibodies are factors of poor prognosis because they are associated with destructive polyarthritis, sometimes complicated with extra-articular signs (nodules, vasculitis). Among the new autoantibodies being studied, only anti-Sa appears to have real diagnostic and prognostic value. The recent data must be confirmed. STRATEGIES FOR OVERT DISEASE: Systematic and repeated assay of autoantibody levels is not warranted in patients with overt disease. Anti-Ro-SS/A, ANCA can however, in some cases, detect unusual complications. THREE STRATEGIES WOULD BE PARTICULARLY INTERESTING: The first is to search for highly specific markers with the aim of identifying a subgroup of rheumatoid arthritis patients as early as possible who have specifically defined clinical, biological and disease-progression criteria. The second is to validate composite scores integrating autoantibodies to achieve early definition of disease severity. The third is to search for markers of progression, particularly autoantibodies, that could modulate inflammatory processes and osteo-cartilaginous degeneration.

Topics: Antibodies, Antineutrophil Cytoplasmic; Antibody Specificity; Arthritis, Rheumatoid; Autoantibodies; Biomarkers; Enzyme-Linked Immunosorbent Assay; Epidermis; Filaggrin Proteins; Fluorescent Antibody Technique; Humans; Immunoglobulin M; Intermediate Filament Proteins; Keratins; Peroxidase; Prognosis; Rheumatoid Factor; Ribonucleoproteins; Sensitivity and Specificity

Topics: Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Humans; Lupus Erythematosus, Systemic; Myeloblastin; Peroxidase; Serine Endopeptidases

Atypical antineutrophil cytoplasm antibodies (A-ANCA) are defined here as ANCA detected by IIF and not directed against the predominant ANCA antigens, proteinase 3 (PR3) and myeloperoxidase (MPO). A-ANCA are found in a variety of clinical conditions, namely rheumatoid arthritis, inflammatory bowel diseases, chronic hepatic diseases and several infections including HIV infection. They are directed against a variety of still ill-defined neutrophil antigens and most frequently yield a perinuclear pattern (P-ANCA) of binding by indirect immunofluorescence on ethanol fixed neutrophils. This paper reviews the literature on A-ANCA and our recent data suggesting that, among others, cathepsin G is one of the predominant antigen targets of A-ANCA. From a clinical point of view, the distinction between MPO-ANCA and A-ANCA is not possible by indirect immunofluorescence (IIF). The determination of ANCA antigens by specific ELISA is therefore necessary to differentiate P-ANCA with MPO specificity from those with undefined specificity. This is of importance because the clinical value of MPO-ANCA is clearly established while the presence of A-ANCA is difficult to interpret given their occurrence in a large variety of clinical conditions.

Topics: Antibodies, Antineutrophil Cytoplasmic; Antibody Specificity; Arthritis, Rheumatoid; Autoantibodies; Autoantigens; Autoimmune Diseases; Cathepsin G; Cathepsins; Cytoplasm; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique; Humans; Infections; Inflammatory Bowel Diseases; Liver Diseases; Myeloblastin; Neutrophils; Pancreatic Elastase; Peroxidase; Serine Endopeptidases

Reactive oxygen metabolic products derived from an activated NADPH oxidase present in the cell membrane of PMNs and mononuclear phagocytic cells play a critical role in the host's defense against bacterial infection. Recent studies have also demonstrated the ability of these toxic products to initiate eukaryotic cell injury and promote the development of the acute inflammatory responses. Experimental studies suggest that neutrophil-derived oxygen metabolites contribute to the development of the tissue injury associated with a variety of disease states, including emphysema, myocardial infarction, adult respiratory distress syndrome, immune complex-mediated vasculitis, and rheumatoid arthritis. Future studies to define further the mechanisms by which reactive oxygen-derived metabolic products mediate tissue injury will provide insight into the development of new therapeutic strategies for the modulation of disease states that are mediated by the recruitment and activation of PMNs.

Topics: Animals; Arthritis, Rheumatoid; Ascorbic Acid; Autoimmune Diseases; Ceruloplasmin; Chemotactic Factors; Cricetinae; Cricetulus; Free Radicals; Humans; Immune Complex Diseases; Inflammation; Lipid Peroxides; Myocardial Infarction; NADH, NADPH Oxidoreductases; NADPH Oxidases; Neutrophils; Oxidation-Reduction; Oxygen; Pancreatic Elastase; Peroxidase; Peroxidases; Peroxides; Phagocytosis; Pulmonary Emphysema; Respiratory Distress Syndrome; Superoxide Dismutase; Superoxides; Vasculitis; Vitamin E

The present study evaluated the effect of infliximab on the myeloperoxidase (MPO) concentration in chronic inflammatory joint disease. Eighteen patients were divided into active and inactive groups. Erythrocyte sedimentation rate, C-reactive protein, white blood cell counts, MPO concentration, and biomarkers of oxidative stress were measured before and after the infusion of infliximab. Patients with active disease showed increases in concentrations of MPO and biomarkers of oxidation, but decreases in antioxidant parameters. After infliximab treatment, both inflammatory parameters and MPO concentrations were normalized.. (1) the MPO concentration is related to inflammatory activity and could play an important role in the maintenance and outbreak of oxidative stress present in these diseases, and (2) infliximab inhibits MPO concentration.

Topics: Adult; Aged; Anti-Inflammatory Agents; Antibodies, Monoclonal; Arthritis, Rheumatoid; Biomarkers; Female; Humans; Infliximab; Male; Middle Aged; Oxidative Stress; Peroxidase; Spondylitis, Ankylosing

We encountered an 86-year-old Japanese woman who presented with proteinuria (0.4 g/day) and hematuria (red blood cell sediment >100/high-power field), a decreased renal function (serum creatinine, 1.51 mg/dL), and elevated myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) levels (231 IU/mL) during treatment of rheumatoid arthritis with abatacept (a cytotoxic T-lymphocyte-associated antigen 4 agent) and adalimumab (a tumor necrosis factor-α agent). A kidney biopsy showed pauci-immune necrotizing glomerulonephritis, and ANCA-associated vasculitis was diagnosed. Treatment with tocilizumab (an interleukin 6 receptor antibody) monotherapy resulted in the improvement of renal findings and normalization of rheumatoid arthritis disease activity and serum ANCA levels. Tocilizumab can also suppress ANCA-associated vasculitis.

Topics: Abatacept; Adalimumab; Aged, 80 and over; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Female; Glomerulonephritis; Humans; Nephritis; Peroxidase

BACKGROUND Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a form of vasculitis predominantly affecting small blood vessels and systemic organs, including the lungs and kidneys. The serum ANCA is an important diagnostic marker for AAV. However, ANCA levels can be nonspecifically elevated in autoimmune diseases like rheumatoid arthritis (RA) and some infectious diseases. Furthermore, RA and AAV can occur together. Therefore, when ANCA is detected in patients with RA, interpretation of the results is often difficult. CASE REPORT A 71-year-old woman with a 15-year history of RA was admitted to our hospital with a fever and anorexia. She was treated with prednisolone 5 mg/day and iguratimod 50 mg/day for the RA. She presented with bilateral frosted glass shadows in the lungs, acute kidney injury, positive myeloperoxidase (MPO)-ANCA results, and elevated ß-D-glucan levels, suggesting AAV or pneumocystis pneumonia. A renal biopsy and bronchoalveolar lavage ruled out AAV. A polymerase chain reaction of the bronchoalveolar lavage fluid was positive for Pneumocystis jirovecii DNA, leading to a diagnosis of pneumocystis pneumonia. After admission, the patient continued to receive intravenous supplemental fluids, and renal function improved. Based on her pathological test results and clinical course, acute kidney injury was diagnosed as prerenal failure due to dehydration in the background of chronic kidney disease. CONCLUSIONS Even if MPO-ANCA is positive in patients with RA, it is important to consider the possibility of a false-positive result and perform a thorough and aggressive examination.

Topics: Acute Kidney Injury; Aged; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Female; Humans; Peroxidase; Pneumonia, Pneumocystis

Background: Cardiovascular (CV) morbidity, mortality and metabolic syndrome are associated with rheumatoid arthritis (RA). A recent trial has suggested increased risk of major CV events (MACE) upon the Janus kinase (JAK) inhibitor tofacitinib compared with anti-tumor necrosis factor α (TNF-α) therapy. In our study, we evaluated lipids and other metabolic markers in relation to vascular function and clinical markers in RA patients undergoing one-year tofacitinib therapy. Patients and methods: Thirty RA patients treated with either 5 mg or 10 mg bid tofacitinib were included in a 12-month follow-up study. Various lipids, paraoxonase (PON1), myeloperoxidase (MPO), thrombospondin-1 (TSP-1) and adipokine levels, such as adiponectin, leptin, resistin, adipsin and chemerin were determined. In order to assess flow-mediated vasodilation (FMD), common carotid intima-media thickness (IMT) and arterial pulse-wave velocity (PWV) ultrasonography were performed. Assessments were carried out at baseline, and 6 and 12 months after initiating treatment. Results: One-year tofacitinib therapy significantly increased TC, HDL, LDL, APOA, APOB, leptin, adipsin and TSP-1, while significantly decreasing Lp(a), chemerin, PON1 and MPO levels. TG, lipid indices (TC/HDL and LDL/HDL), adiponectin and resistin showed no significant changes. Numerous associations were found between lipids, adipokines, clinical markers and IMT, FMD and PWV (p < 0.05). Regression analysis suggested, among others, association of BMI with CRP and PWV (p < 0.05). Adipokines variably correlated with age, BMI, CRP, CCP, FMD, IMT and PWV, while MPO, PON1 and TSP-1 variably correlated with age, disease duration, BMI, RF and PWV (p < 0.05). Conclusions: JAK inhibition by tofacitinib exerts balanced effects on lipids and other metabolic markers in RA. Various correlations may exist between metabolic, clinical parameters and vascular pathophysiology during tofacitinib treatment. Complex assessment of lipids, metabolic factors together with clinical parameters and vascular pathophysiology may be utilized in clinical practice to determine and monitor the CV status of patients in relation with clinical response to JAK inhibition.

Topics: Adipokines; Adiponectin; Apolipoproteins A; Apolipoproteins B; Arthritis, Rheumatoid; Aryldialkylphosphatase; Biomarkers; Carotid Intima-Media Thickness; Complement Factor D; Follow-Up Studies; Humans; Janus Kinase Inhibitors; Janus Kinases; Leptin; Lipids; Peroxidase; Resistin; Thrombospondin 1; Tumor Necrosis Factor-alpha

Cardiovascular (CV) morbidity, mortality, and metabolic syndrome are associated with rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Here, lipids and other metabolic markers in relation to vascular function and clinical markers were evaluated in RA and AS patients undergoing one-year anti-TNF therapy.. Fifty-three patients including 36 RA patients treated with either etanercept (ETN) or certolizumab pegol (CZP) and 17 AS patients treated with ETN were included in a 12-month follow-up study. Various lipids, paraoxonase (PON) and arylesterase (ARE) activities, myeloperoxidase (MPO) and adipokine levels were determined overtime. Ultrasonography was performed to determine flow-mediated vasodilation (FMD), common carotid intima-media thickness (ccIMT), and arterial pulse-wave velocity (PWV) in all patients. All assessments were performed at baseline and 6 and 12 months after treatment initiation.. Anti-TNF therapy decreased ARE activity, MPO, adiponectin, and chemerin levels after 12 months (. Assessment of various metabolic parameters together with disease activity, CRP, and ultrasound-based techniques may exert additional value in determining CV burden and in monitoring the effects of biologics on preclinical vascular pathophysiology.

Topics: Adult; Aged; Aged, 80 and over; Arthritis, Rheumatoid; Aryldialkylphosphatase; Biomarkers; C-Reactive Protein; Carboxylic Ester Hydrolases; Carotid Intima-Media Thickness; Certolizumab Pegol; Etanercept; Female; Heart Disease Risk Factors; Humans; Lipid Metabolism; Lipids; Male; Middle Aged; Obesity; Peroxidase; Spondylitis, Ankylosing; Tumor Necrosis Factor-alpha

Rheumatoid arthritis is an inflammatory disease with joint manifestations. In the presence of extra-articular manifestations, the morbidity and severity of the disease increase. Glucocorticoid is used as a treatment and may result in side effects related to cardiovascular risk.. This was a cross-sectional study including 59 volunteers with rheumatoid arthritis receiving treatment at a hospital of Campos Gerais that aimed to establish the relation between cardiovascular risk, glucocorticoid treatment and myeloperoxidase in these patients. Subjects were divided into two groups: using (n = 39) and without glucocorticoids (n = 20). They underwent clinical evaluation, physical examination and blood samples were taken. Statistical analysis was performed using Student's t test and Mann-Whitney test. Logistic regression was performed to assess the cardiovascular risk. The significance level was 5% (α = 0.05). Calculations were performed using the Statistical Package for the Social Science version 21.0.. There has been a significant difference between groups in blood glucose values (p = 0.012), which can be explained by the different percentage of diabetic patients in the groups. When assessing cardiovascular risk using the predictors of glucocorticoid dose, time of glucocorticoid use, myeloperoxidase, and C-reactive protein together, these were responsible for significantly predicting this risk (p = 0.015).. A significant relation between the predictor myeloperoxidase alone was also demonstrated (p = 0.037), it may be an important predictor of cardiovascular risk among individuals with rheumatoid arthritis.

Topics: Adult; Aged; Arthritis, Rheumatoid; Blood Glucose; C-Reactive Protein; Cardiovascular Diseases; Cross-Sectional Studies; Dose-Response Relationship, Drug; Female; Glucocorticoids; Heart Disease Risk Factors; Humans; Male; Middle Aged; Peroxidase; Time Factors

Tumour necrosis factor (TNF) inhibitors are used against a variety of connective tissue diseases, including rheumatoid arthritis. Contrarily, although rare, TNF inhibitors are known to induce autoimmune diseases, such as systemic lupus erythematosus and psoriasis as a paradoxical reaction. We experienced a case of rapidly progressive glomerulonephritis after introduction of certolizumab pegol. The patient was a 30-year-old woman who was previously diagnosed with rheumatoid arthritis in X-8. She received treatment with methotrexate (8 mg/week) and infliximab (3 mg/kg/8 weeks), following which she showed low disease activity and remission. In September X-1, methotrexate and infliximab were discontinued and certolizumab pegol was introduced because she desired to bear children. In March X, the patient experienced renal dysfunction, and urinary protein analysis revealed positivity for myeloperoxidase anti-neutrophil cytoplasmic autoantibody. Renal biopsy showed crescentic glomerulonephritis, and the patient was diagnosed with rapidly progressive glomerulonephritis due to TNF inhibitor-induced microscopic polyangiitis. As she desired to bear children, rituximab was introduced in addition to corticosteroids, which led to remission of the symptoms. TNF inhibitors should be discontinued in patients who develop rapidly progressive glomerulonephritis, and these patients should be treated with immunosuppressive drugs, such as massive corticosteroids and cyclophosphamide. In the present case, rituximab was useful for not only the treatment, but also for the preservation of fertility.

Topics: Adult; Arthritis, Rheumatoid; Autoantibodies; Certolizumab Pegol; Female; Glomerulonephritis; Humans; Kidney; Methotrexate; Peroxidase; Rituximab; Tumor Necrosis Factor Inhibitors

The aim of this study is to evaluate dysfunctional high-density lipoprotein cholesterol (HDL) by measuring myeloperoxidase (MPO)/paraoxonase 1 (PON1) ratio in patients with rheumatoid arthritis (RA) and to investigate the relationship between dysfunctional HDL and cardiovascular disease (CVD) in RA patients.. Sixty-seven healthy individuals and 130 RA patients were included in the study. Routine lipid panels (triglyceride (TG), low-density lipoprotein cholesterol (LDL), HDL, total cholesterol (TC), PON1 and MPO levels were measured. Disease activity scores-28 (DAS28) of RA patients were calculated. Cardiological examination records of the patients were assessed to detect patients who also have CVD.. There were no significant differences between RA and control groups in routine lipid profiles (P > .05 for all). MPO/PON1 ratios were significantly elevated in the RA group compared with the control group (P < .001). MPO/PON1 ratios were higher in RA patients with CVD history compared with those without CVD (P < .05). MPO/PON1 ratios were correlated with DAS28 scores (rho: 0.357, P < .001).. HDL dysfunction determined by the MPO/PON1 ratio may be associated with the pathophysiology of increased CVD in RA. Thus, evaluating dysfunctional HDL levels by measuring the MPO/PON1 ratio in RA patients may allow more detailed patient follow-up, as well as the reduction of CVD events in RA patients with therapeutic agents aiming to increase the functional properties of HDL by decreasing this ratio.

Topics: Arthritis, Rheumatoid; Aryldialkylphosphatase; Humans; Lipoproteins, HDL; Peroxidase; Triglycerides

Rheumatoid arthritis (RA) is a chronic inflammatory disorder affecting synovial joints. Neutrophils are believed to play an important role in both the initiation and progression of RA, and large numbers of activated neutrophils are found within both synovial fluid (SF) and synovial tissue from RA joints. In this study we analyzed paired blood and SF neutrophils from patients with severe, active RA (DAS28>5.1, n=3) using RNA-seq. 772 genes were significantly different between blood and SF neutrophils. IPA analysis predicted that SF neutrophils had increased expression of chemokines and ROS production, delayed apoptosis, and activation of signaling cascades regulating the production of NETs. This activated phenotype was confirmed experimentally by incubating healthy control neutrophils in cell-free RA SF, which was able to delay apoptosis and induce ROS production in both unprimed and TNFα primed neutrophils (p<0.05). RA SF significantly increased neutrophil migration through 3μM transwell chambers (p<0.05) and also increased production of NETs by healthy control neutrophils (p<0.001), including exposure of myeloperoxidase (MPO) and citrullinated histone-H3-positive DNA NETs. IPA analysis predicted NET production was mediated by signaling networks including AKT, RAF1, SRC, and NF-κB. Our results expand the understanding of the molecular changes that take place in the neutrophil transcriptome during migration into inflamed joints in RA, and the altered phenotype in RA SF neutrophils. Specifically, RA SF neutrophils lose their migratory properties, residing within the joint to generate signals that promote joint damage, as well as inflammation

Topics: Apoptosis; Arthritis, Rheumatoid; Chemokines; Extracellular Traps; Female; Humans; Inflammation; Joints; Male; Middle Aged; Neutrophil Activation; Neutrophils; Peroxidase; Reactive Oxygen Species; Signal Transduction; Synovial Fluid; Synovial Membrane

Topics: Albumins; Arthritis, Rheumatoid; Cells, Cultured; Extracellular Traps; Humans; Neutrophils; Peroxidase; Protein Carbamylation; Reactive Oxygen Species

Neutrophil extracellular traps (NETs) comprise a unique form of non-apoptotic cell death exhibited by neutrophils, which occurs in a stepwise process termed NETosis. It has been postulated that NETosis plays an important role in the pathogenesis of autoimmune disorders. The aim of this study was to evaluate serum levels of NET remnants in patients with rheumatoid arthritis (RA), as well as potential associations between NET remnants and indicators of RA.. Serum levels of myeloperoxidase (MPO)-DNA complexes (NET remnants) were examined in 74 RA patients and 50 healthy controls using a modified enzyme-linked immunosorbent assay. Associations between the levels of these complexes and indicators of RA were then statistically evaluated.. RA patients exhibited significantly higher levels of MPO-DNA complexes than the healthy controls, and these levels were associated with increased neutrophil counts and positivity for rheumatoid factor (RF) and anti-citrullinated protein/peptide antibodies (ACPA). Among the 63 ACPA-positive RA patients examined, those with ACPA titers > 1600 U/mL showed significantly increased MPO-DNA levels. Receiver operating characteristic analysis determined that the area under the curve for all 74 RA patients was 0.798, with a sensitivity of 91.9% and a specificity of 56.0%, while that for the ACPA-negative patients was 0.891, with a sensitivity and specificity of 81.8% and 84.0%, respectively.. The results of this study suggest that the disease status of RA is associated with increased NETosis. In particular, evaluation of serum MPO-DNA levels may comprise a useful complementary tool for discriminating RA patients from healthy individuals.

Topics: Adult; Area Under Curve; Arthritis, Rheumatoid; Biomarkers; Case-Control Studies; Cell-Free Nucleic Acids; Enzyme-Linked Immunosorbent Assay; Extracellular Traps; Female; Humans; Leukocyte Count; Male; Middle Aged; Neutrophils; Peroxidase; Predictive Value of Tests; Reproducibility of Results; ROC Curve; Up-Regulation

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by cellular infiltration into the joints and cartilage destruction. Neutrophils play a crucial role in the pathogenesis of RA. Triptolide (TP) is a bioactive compound derived from Tripterygium wilfordii Hook F, which has been used in folk medicine as a treatment for a variety of inflammatory disorders, including RA, for many centuries. Previous studies have shown that TP possesses anti-arthritic activity. However, the anti-arthritic mechanism of TP remains to be fully defined. In the present study, we used the adjuvant-induced arthritis (AA) murine model of RA to investigate the impact of TP on RA and neutrophil function. TP alleviated AA by reducing neutrophil recruitment and suppressing the expression of interleukin-6 and tumour necrosis factor-α in vivo. TP also suppressed the expression of pro-inflammatory cytokines in neutrophils, promoted neutrophil apoptosis and inhibited the migration, NETosis and autophagy of neutrophils in vitro. Based on our findings, TP effectively ameliorates RA by down-regulating neutrophil inflammatory functions, indicating that TP represents a potential therapeutic agent for RA.

Topics: Animals; Apoptosis; Arthritis, Experimental; Arthritis, Rheumatoid; Autophagy; Chronic Disease; Cytokines; Diterpenes; Epoxy Compounds; Extracellular Traps; Inflammation; Leukocyte Elastase; Lipopolysaccharides; Male; Mice, Inbred C57BL; Neutrophil Infiltration; Neutrophils; Peroxidase; Phenanthrenes

1) To assess the association of NETosis and NETosis-derived products with the activity of the disease and the development of cardiovascular disease in RA; 2) To evaluate the involvement of NETosis on the effects of biologic therapies such as anti-TNF alpha (Infliximab) and anti-IL6R drugs (Tocilizumab).. One hundred and six RA patients and 40 healthy donors were evaluated for the occurrence of NETosis. Carotid-intimae media thickness was analyzed as early atherosclerosis marker. Inflammatory and oxidative stress mediators were quantified in plasma and neutrophils. Two additional cohorts of 75 RA patients, treated either with Infliximab (n = 55) or Tocilizumab (n = 20) for six months, were evaluated.. NETosis was found increased in RA patients, beside myeloperoxidase and neutrophil elastase protein levels. Cell-free nucleosomes plasma levels were elevated, and strongly correlated with the activity of the disease and the positivity for autoantibodies, alongside inflammatory and oxidative profiles in plasma and neutrophils. Moreover, ROC analyses showed that cell-free nucleosomes levels could identify RA patients showing early atherosclerosis with high specificity. RA patients treated either with IFX or TCZ for six months exhibited decreased generation of NETs. Concomitantly, clinical parameters and serum markers of inflammation were found reduced. Mechanistic in vitro analyses showed that inhibition of NETs extrusion by either DNase, IFX or TCZ, further abridged the endothelial dysfunction and the activation of immune cells, thus influencing the global activity of the vascular system.. NETosis-derived products may have diagnostic potential for disease activity and atherosclerosis, as well as for the assessment of therapeutic effectiveness in RA.

Topics: Aged; Antirheumatic Agents; Arthritis, Rheumatoid; Atherosclerosis; Biomarkers; Case-Control Studies; Comorbidity; Extracellular Traps; Female; Humans; Inflammation Mediators; Interleukin-6; Male; Middle Aged; Oxidative Stress; Peroxidase; Risk Factors; ROC Curve; Severity of Illness Index; Treatment Outcome; Tumor Necrosis Factor-alpha

Rheumatoid arthritis (RA) is a chronic immune inflammatory disease mediated by the influx of immune cells into the synovial joint space. As Tanshinone IIA (TIIA) has potent anti-oxidant and anti-inflammatory activities, we used the adjuvant-induced arthritis (AA) murine model of RA to investigate the impact of TIIA on RA and immune cell activation. The anti-arthritic activity of TIIA was investigated in an adjuvant-induced arthritis model of RA in mice. Myeloperoxidase and neutrophil elastase expression levels were assessed in ankle joints by immunohistochemistry analysis. Immune cell infiltration was evaluated in air pouch experiments. Proinflammatory cytokines expression levels were determined by quantitative real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assays. Neutrophil extracellular traps (NETs) were assessed by immunostaining and confocal microscopy. Treatment with TIIA alleviated cartilage erosion and neutrophil infiltration in the ankle joints of AA mice and reduced proinflammatory cytokine expression levels in sera. TIIA suppressed interleukin-6 and tumour necrosis factor-α expression and release in neutrophils and promoted neutrophil apoptosis. TIIA also inhibited the NET formation of neutrophils. Our findings demonstrated that TIIA can ameliorate RA effectively by targeting neutrophils, indicating that TIIA may act as a potential therapeutic for RA.

Topics: Abietanes; Animals; Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; Arthritis, Experimental; Arthritis, Rheumatoid; Cartilage; Extracellular Traps; Female; Humans; Interleukin-6; Leukocyte Elastase; Mice; Mice, Inbred C57BL; Neutrophils; Peroxidase; Salvia miltiorrhiza; Tumor Necrosis Factor-alpha

Topics: Adult; Antibodies, Antineutrophil Cytoplasmic; Antirheumatic Agents; Arthritis, Rheumatoid; Biopsy; Drug Substitution; Etanercept; Female; Glomerulonephritis; Glucocorticoids; Humans; Immunosuppressive Agents; Kidney Glomerulus; Microscopy, Electron; Peroxidase; Treatment Outcome; Tumor Necrosis Factor-alpha

Neutrophils are implicated in the pathology of rheumatoid arthritis (RA), but the mechanisms regulating their activation are largely unknown. RA is a heterogeneous disease, and whereas many patients show clinical improvement during TNF inhibitor (TNFi) therapy, a significant proportion fails to respond. In vitro activation of neutrophils with agents, including TNF, results in rapid and selective changes in gene expression, but how neutrophils contribute to TNF signaling in RA and whether TNFi sensitivity involves differential neutrophil responses are unknown. With the use of RNA sequencing (RNA-Seq), we analyzed blood neutrophils from 20 RA patients, pre-TNFi therapy, to identify biomarkers of response, measured by a decrease in disease activity score based on 28 joint count (DAS28), 12 wk post-therapy. Biomarkers were validated by quantitative PCR (qPCR) of blood neutrophils from 2 further independent cohorts of RA patients: 16 pre-TNFi and 16 predisease-modifying anti-rheumatic drugs (DMARDs). Twenty-three neutrophil transcripts predicted a 12-wk response to TNFi: 10 (IFN-regulated) genes predicting a European League against Rheumatism (EULAR) good response and 13 different genes [neutrophil granule protein (NGP) genes] predicting a nonresponse. Statistical analysis indicated a predictive sensitivity and specificity of each gene in the panel of >80%, with some 100% specific. A combination of 3 genes [

Topics: Arthritis, Rheumatoid; Biomarkers; Cohort Studies; Gene Expression Profiling; Humans; Neutrophils; Pancreatic Elastase; Peroxidase; Reproducibility of Results; ROC Curve; Sequence Analysis, RNA; Transcriptome; Tumor Necrosis Factor-alpha

The aim was to investigate the effects of nicotine on neutrophil extracellular traps (NETs) formation in current and non-smokers and on a murine model of RA.. We compared spontaneous and phorbol 12-myristate 13-acetate-induced NETosis between current and non-smokers by DNA release binding. Nicotine-induced NETosis from non-smokers was assessed by DNA release binding, NET-specific (myeloperoxidase (MPO)-DNA complex) ELISA and real-time fluorescence microscopy. We also used immunofluorescent staining to detect nicotinic acetylcholine receptors (nAChRs) on neutrophils and performed a functional analysis to assess the role of nAChRs in nicotine-induced NETosis. Finally, we investigated the effects of systemic nicotine exposure on arthritis severity and NETosis in the CIA mouse model.. Neutrophils derived from current smokers displayed elevated levels of spontaneous and phorbol 12-myristate 13-acetate-induced NETosis. Nicotine induced dose-dependent NETosis in ex vivo neutrophils from healthy non-smokers, and co-incubation with ACPA-immune complexes or TNF-α facilitated a synergistic effect on NETosis. Real-time fluorescence microscopy revealed robust formation of NET-like structures in nicotine-exposed neutrophils. Immunofluorescent staining demonstrated the presence of the α7 subunit of the nAChR on neutrophils. Stimulation of neutrophils with an α7-specific nAChR agonist induced NETosis, whereas pretreatment with an nAChR antagonist attenuated nicotine-induced NETosis. Nicotine administration to mice with CIA exacerbated inflammatory arthritis, with higher plasma levels of NET-associated MPO-DNA complex.. We demonstrate that nicotine is a potent inducer of NETosis, which may play an important role in accelerating arthritis in the CIA model. This study generates awareness of and the mechanisms by which nicotine-containing products, including e-cigarettes, may have deleterious effects on patients with RA.

Topics: Animals; Arthritis, Experimental; Arthritis, Rheumatoid; Cartilage; Dose-Response Relationship, Drug; Electronic Nicotine Delivery Systems; Enzyme-Linked Immunosorbent Assay; Extracellular Traps; Humans; Infusions, Subcutaneous; Male; Mice, Inbred DBA; Neutrophils; Nicotine; Nicotinic Agonists; Peroxidase; Smoking; Tetradecanoylphorbol Acetate

To clarify the roles of neutrophils in anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitic neuropathy, we studied neutrophil extracellular traps (NETs) in peripheral nerve vasculitis. Stored nerve samples from 17 patients with microscopic polyangiitis (MPA) were immunohistochemically analyzed using antibodies for citrullinated histone H3 (citH3) and various neutrophil enzymes. We defined merged citH3 and extracellularly released myeloperoxidase (MPO) as NET formation. We also compared NET formation between MPO-ANCA-positive/negative MPA and rheumatoid arthritis (RA)-associated vasculitic neuropathy. NETs were identified mostly in vasculitic small arterioles of 6 of 12 MPO-ANCA-positive MPA patients, and their frequency was higher (p < 0.05) than in ANCA-negative patients. NETs were not found in vasculitic neuropathy with RA or patients with chronic inflammatory demyelinating polyradiculoneuropathy. NETs were also observed in the peripheral nervous system of MPA patients as well as in the lung and kidney. These results suggest that NETs may be involved in the pathogenesis of MPA neuropathy.

Topics: Aged; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Extracellular Traps; Female; Humans; Japan; Kidney; Male; Microscopic Polyangiitis; Middle Aged; Neutrophils; Peripheral Nerves; Peripheral Nervous System Diseases; Peroxidase; Retrospective Studies

Seropositive rheumatoid arthritis (RA) is characterized by autoantibodies binding to citrullinated and homocitrullinated proteins. We wanted to study the expression patterns of these disease-associated protein forms and if the rheumatoid nodule and synovial tissue itself contain biologically active levels of citrullinating peptidyl arginine deiminases 2, 3 and 4 and homocitrullination-facilitating neutrophil enzyme myeloperoxidase.. Total of 195 synovial samples from metatarsal joints from five ACPA/RF-positive RA patients (n = 77), synovial samples from knees of eight seropositive RA (n = 60), seven seronegative RA (n = 33) and five osteoarthritis (n = 25) patients were analyzed for citrulline and homocitrulline contents using HPLC. The location of citrulline- and homocitrulline-containing proteins, PAD 2, 3, 4 and myeloperoxidase were shown by immunostaining. Myeloperoxidase and citrulline- or homocitrulline-containing proteins were stained on Western blot.. Overall, necrosis was frequent in metatarsals of seropositive RA and absent in seronegative RA and osteoarthritis patients. In histological analysis, there was a significant local patterning and variation in the citrulline and homocitrulline content and it was highest in metatarsal synovial tissues of seropositive RA patients. We found peptidyl arginine deiminase 2, 3 and 4 in the lining and sublining layers of intact synovial tissue. Myeloperoxidase was found locally around necrotic areas. The tissues with necrosis contained the highest levels of citrulline and homocitrulline.. Rheumatoid nodules and synovia contain significant amount of PAD2, 3 and 4 and myeloperoxidase enzymes. These enzymes could explain the levels of citrulline and homocitrulline in seropositive RA synovial and rheumatoid nodule tissues especially around necrotic tissue.

Topics: Aged; Arthritis, Rheumatoid; Autoantigens; Blotting, Western; Chromatography, High Pressure Liquid; Citrulline; Female; Humans; Hydrolases; Immunohistochemistry; Male; Middle Aged; Peroxidase; Protein-Arginine Deiminase Type 2; Protein-Arginine Deiminases

The K/BxN serum-transfer arthritis is a widely-used translational mouse model of rheumatoid arthritis, in which the immunological components have thoroughly been investigated. In contrast, little is known about the role of sensory neural factors and the complexity of neuro-immune interactions. Therefore, we analyzed the involvement of capsaicin-sensitive peptidergic sensory nerves in autoantibody-induced arthritis with integrative methodology.. Arthritogenic K/BxN or control serum was injected to non-pretreated mice or resiniferatoxin (RTX)-pretreated animals where capsaicin-sensitive nerves were inactivated. Edema, touch sensitivity, noxious heat threshold, joint function, body weight and clinical arthritis severity scores were determined repeatedly throughout two weeks. Micro-CT and in vivo optical imaging to determine matrix-metalloproteinase (MMP) and neutrophil-derived myeloperoxidase (MPO) activities, semiquantitative histopathological scoring and radioimmunoassay to measure somatostatin in the joint homogenates were also performed.. In RTX-pretreated mice, the autoantibody-induced joint swelling, arthritis severity score, MMP and MPO activities, as well as histopathological alterations were significantly greater compared to non-pretreated animals. Self-control quantification of the bone mass revealed decreased values in intact female mice, but significantly greater arthritis-induced pathological bone formation after RTX-pretreatment. In contrast, mechanical hyperalgesia from day 10 was smaller after inactivating capsaicin-sensitive afferents. Although thermal hyperalgesia did not develop, noxious heat threshold was significantly higher following RTX pretreatment. Somatostatin-like immunoreactivity elevated in the tibiotarsal joints in non-pretreated, which was significantly less in RTX-pretreated mice.. Although capsaicin-sensitive sensory nerves mediate mechanical hyperalgesia in the later phase of autoantibody-induced chronic arthritis, they play important anti-inflammatory roles at least partially through somatostatin release.

Topics: Animals; Arthritis, Experimental; Arthritis, Rheumatoid; Capsaicin; Disease Models, Animal; Diterpenes; Edema; Hindlimb; Hyperalgesia; Matrix Metalloproteinases; Mice; Mice, Inbred C57BL; Nociceptors; Pain Threshold; Peroxidase; Reactive Oxygen Species; Sensory System Agents; Somatostatin; Tarsus, Animal; TRPV Cation Channels; X-Ray Microtomography

Human ceruloplasmin (CP) is a multifunctional copper-binding protein produced in the liver. CP oxidizes Fe(2+) to Fe(3+), decreasing the concentration of Fe(2+) available for generating harmful oxidant species. CP is also a potent inhibitor of leukocyte myeloperoxidase (MPO) (Kd=130nM), a major source of oxidants in vivo. Rheumatoid arthritis (RA) is an inflammatory autoimmune disease affecting flexible joints and characterized by activation of both inflammatory and coagulation processes. Indeed, the levels of CP, MPO, and thrombin are markedly increased in the synovial fluid of RA patients. Here we show that thrombin cleaves CP in vitro at (481)Arg-Ser(482) and (887)Lys-Val(888) bonds, generating a nicked species that retains the native-like fold and the ferroxidase activity of the intact protein, whereas the MPO inhibitory function of CP is abrogated. Analysis of the synovial fluid of 24 RA patients reveals that CP is proteolytically degraded to a variable extent, with a fragmentation pattern similar to that observed with thrombin in vitro, and that proteolysis is blocked by hirudin, a highly potent and specific thrombin inhibitor. Using independent biophysical techniques, we show that thrombin has intrinsic affinity for CP (Kd=60-270nM), independent of proteolysis, and inhibits CP ferroxidase activity (KI=220±20nM). Mapping of thrombin binding sites with specific exosite-directed ligands (i.e., hirugen, fibrinogen γ'-peptide) and thrombin analogues having the exosites variably compromised (i.e., prothrombin, prethrombin-2, βT-thrombin) reveals that the positively charged exosite-II of thrombin binds to the negatively charged upper region of CP, while the protease active site and exosite-I remain accessible. These results suggest that thrombin can exacerbate inflammation in RA by impairing the MPO inhibitory function of CP via proteolysis and by competitively inhibiting CP ferroxidase activity. Notably, local administration of hirudin, a highly potent and specifc thrombin inhibitor, reduces the concentration of active MPO in the synovial fluid of RA patients and has a beneficial effect on the clinical symptoms of the disease.

Topics: Aged; Arthritis, Rheumatoid; Case-Control Studies; Ceruloplasmin; Female; Humans; Male; Middle Aged; Models, Molecular; Peroxidase; Protein Interaction Domains and Motifs; Thrombin

Plasma and synovial myeloperoxidase (MPO) and its products were strongly associated with osteoarthritis (OA) and rheumatoid arthritis (RA). In addition, it is well known that there is a link between oxidative stress and cytokines. The present study aims at investigating the link between synovial MPO (and its products), interleukin (IL)-18, which is involved in the degradation of articular cartilage in RA, and IL-8, which is involved in recruitment and activation of neutrophils during inflammation. Effects of the treatment of RA on the biological parameters were also investigated.. Patients (n = 105) were studied including 39 patients with OA, 33 with RA and 33 with RA receiving a specific treatment. Disease activity score (DAS-28) was calculated whereas MPO antigen/activity, neutrophils, chloro-tyrosine (Cl-Tyr), homocitrulline (Hcit), IL-8, and IL-18 were measured in synovial fluid (SF) and CRP was measured in serum.. DAS-28 and CRP levels were not significantly different between groups. MPO activity, and MPO, Cl-Tyr, and Hcit levels were significantly higher in SF of RA patients than OA patients. MPO specific activity (MPO activity/antigen ratio) was significantly lower in treated than in untreated RA patients as was IL-8. MPO activity and concentration were correlated with IL-8 and IL-18 in untreated but not in treated RA patients.. MPO level is related to IL-8 and IL-18 levels in untreated RA patients. A link has been shown between treatment and decrease of IL-8, MPO specific activity and Hcit in SF. The causal role of MPO in SF inflammation and how treatment can affect MPO specific activity need further investigations.

Topics: Arthritis, Rheumatoid; Cytokines; Female; Humans; Interleukin-8; Male; Peroxidase; Synovial Fluid

Myeloperoxidase (MPO) is implicated as a local mediator of tissue damage when released extracellularly in many chronic inflammatory diseases. The purpose of this study was to explore the role of endogenous MPO in experimental rheumatoid arthritis (RA).. K/BxN serum-transfer arthritis was induced in C57BL/6 wild-type (WT) and MPO knockout (MPO(-/-) ) mice, and disease development was assessed. MPO activity was measured in joint tissues from mice with or without K/BxN arthritis. Collagen-induced arthritis (CIA) was induced in WT and MPO(-/-) mice, and disease development and immune responses were examined. MPO expression was assessed in synovial biopsy samples from patients with active RA, and the effect of MPO on synovial fibroblasts was tested in vitro.. MPO was up-regulated in the joints of mice with K/BxN arthritis, and MPO deficiency attenuated the severity of the disease without affecting circulating cytokine levels. In CIA, MPO(-/-) mice had enhanced CD4+ T cell responses and reduced frequency of regulatory T cells in the lymph nodes and spleen, as well as augmented interleukin-17A and diminished interferon-γ secretion by collagen-stimulated splenocytes, without an effect on circulating anticollagen antibody levels. Despite enhanced adaptive immunity in secondary lymphoid organs, CIA development was attenuated in MPO(-/-) mice. Intracellular and extracellular MPO was detected in the synovium of patients with active RA, and human MPO enhanced the proliferation and decreased the apoptosis of synovial fibroblasts in vitro.. MPO contributes to the development of arthritis despite suppressing adaptive immunity in secondary lymphoid organs. This suggests distinct effects of local MPO on arthritogenic effector responses.

Topics: Animals; Arthritis, Experimental; Arthritis, Rheumatoid; Disease Progression; Inflammation; Joints; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Peroxidase; Synovial Membrane

Rheumatoid arthritis (RA) patients usually exhibit immune complex (IC) deposition and increased neutrophil activation in the joint. In this study, we assessed how four flavonols (galangin, kaempferol, quercetin, and myricetin) modulate the effector functions of healthy individuals' and active RA patients' IC-stimulated neutrophils. We measured superoxide anion and total reactive oxygen species production using lucigenin (CL-luc)- and luminol (CL-lum)-enhanced chemiluminescence assays, respectively. Galangin, kaempferol, and quercetin inhibited CL-lum to the same degree (mean IC50=2.5 μM). At 2.5 μM, quercetin and galangin suppressed nearly 65% CL-lum of active RA patients' neutrophils. Quercetin inhibited CL-luc the most effectively (IC50=1.71±0.36 μM). The four flavonols diminished myeloperoxidase activity, but they did not decrease NADPH oxidase activity, phagocytosis, microbial killing, or cell viability of neutrophils. The ability of the flavonols to scavenge hypochlorous acid and chloramines, but not H2O2, depended on the hydroxylation degree of the flavonol B-ring. Therefore, at physiologically relevant concentrations, the flavonols partially inhibited the oxidative metabolism of IC-stimulated neutrophils without affecting the other investigated effector functions. Using these compounds to modulate IC-mediated neutrophil activation is a promising safe therapeutic strategy to control inflammation in active RA patients.

Topics: Adult; Anti-Inflammatory Agents; Antigen-Antibody Complex; Arthritis, Rheumatoid; Cell Degranulation; Cells, Cultured; Female; Flavonoids; Humans; Kaempferols; Middle Aged; Neutrophils; Oxidation-Reduction; Peroxidase; Quercetin; Reactive Oxygen Species; Structure-Activity Relationship

Neutrophil extracellular traps (NETs) have recently been implicated in a number of autoimmune conditions, including rheumatoid arthritis (RA). We examined the underlying signaling pathways triggering enhanced NETosis in RA and ascertained whether the products of NETosis had diagnostic implications or usefulness.. Neutrophils were isolated from RA patients with active disease and from controls. Spontaneous NET formation from RA and control neutrophils was assessed in vitro with microscopy and enzyme-linked immunosorbent assay (ELISA) for NETosis-derived products. The analysis of the signal-transduction cascade included reactive oxygen species (ROS) production, myeloperoxidase (MPO), neutrophil elastase (NE), peptidyl arginine deiminase 4 (PAD4), and citrullinated histone 3 (citH3). NET formation was studied in response to serum and synovial fluid and immunoglobulin G (IgG) depleted and reconstituted serum. Serum was analyzed for NETosis-derived products, for which receiver operator characteristic (ROC) curves were calculated.. Neutrophils from RA cases exhibited increased spontaneous NET formation in vitro, associated with elevated ROS production, enhanced NE and MPO expression, nuclear translocation of PAD4, PAD4-mediated citrullination of H3, and altered nuclear morphology. NET formation in both anti-citrullinated peptide antibody (ACPA)-positive and -negative RA was abolished by IgG depletion, but restored only with ACPA-positive IgG. NETosis-derived products in RA serum demonstrated diagnostic potential, the ROC area under the curve for cell-free nucleosomes being >97%, with a sensitivity of 91% and a specificity of 92%. No significant difference was observed between ACPA-positive and -negative cases.. Signaling elements associated with the extrusion of NETs are significantly enhanced to promote NETosis in RA compared with healthy controls. NETosis depended on the presence of ACPA in ACPA-positive RA serum. The quantitation of NETosis-derived products, such as cell-free nucleosomes in serum, may be a useful complementary tool to discriminate between healthy controls and RA cases.

Topics: Arthritis, Rheumatoid; Autoantibodies; Blotting, Western; Cells, Cultured; Citrulline; DNA; Extracellular Traps; Female; Histones; Humans; Hydrolases; Immunohistochemistry; Leukocyte Elastase; Male; Microscopy, Electron, Scanning; Microscopy, Fluorescence; Middle Aged; Neutrophils; Nucleosomes; Peptides, Cyclic; Peroxidase; Protein-Arginine Deiminase Type 4; Protein-Arginine Deiminases; Reactive Oxygen Species; Reverse Transcriptase Polymerase Chain Reaction; Signal Transduction; Synovial Fluid

The clinical significance of myeloperoxidase (MPO) has been the focus of investigation because it may contribute to the chronic, non-microbial inflammatory process in various diseases. Here, we determined serum MPO levels in rheumatoid arthritis (RA) and other autoimmune or inflammatory conditions, and investigated the associations between MPO levels and disease activity indicators in RA.. The distribution of MPO was determined in serum samples from patients with RA, systemic lupus erythematosus (SLE), primary Sjögren's syndrome (pSS), dermatomyositis (DM), or ankylosing spondylitis (AS) and from healthy controls using commercial ELISA kits. Associations of serum MPO levels with the disease variables of RA patients were evaluated.. All patient samples analyzed showed higher serum levels of MPO than healthy controls. Furthermore, MPO levels in RA were significantly higher than those in the other diseases with the exception of DM. Higher MPO levels were observed in RA patients with increased C-reactive protein (p=0.005) or neutrophil percentage (p<0.001), as well as in those with highly active disease (p<0.001). Moderate positive correlations between MPO levels and IgM (r=0.334, p=0.001), C-reactive protein (r=0.293, p=0.003), erythrocyte sedimentation rate (r=0.240, p=0.016), or DAS28 (r=0.350, p<0.001) were also demonstrated.. The MPO concentration is likely to increase in patients with chronic inflammation. The associations between MPO and the disease variables of RA patients support a role for MPO in the inflammatory process of the disease.

Topics: Adult; Aged; Arthritis, Rheumatoid; Biomarkers; Blood Sedimentation; C-Reactive Protein; Case-Control Studies; Dermatomyositis; Enzyme-Linked Immunosorbent Assay; Female; Humans; Inflammation; Lupus Erythematosus, Systemic; Male; Middle Aged; Peroxidase; Sjogren's Syndrome; Spondylitis, Ankylosing

Phagocyte-derived myeloperoxidase (MPO) and pro-inflammatory high density lipoprotein (HDL) associate with rheumatoid arthritis (RA), but the link between MPO and HDL has not been systematically examined. In this study, we investigated whether MPO can oxidise HDL and determined MPO-specific oxidative signature by apoA-1 by peptide mapping in RA subjects with and without known cardiovascular disease (CVD).. Two MPO oxidation products, 3-chlorotyrosine and 3-nitrotyrosine, were quantified by tandem mass spectrometry (MS/MS) in in vitro model system studies and in plasma and HDL derived from healthy controls and RA subjects. MPO levels and cholesterol efflux were determined. Site-specific nitration and chlorination of apoA-1 peptides were quantified by MS/MS.. RA subjects demonstrated higher levels of MPO, MPO-oxidised HDL and diminished cholesterol efflux. There was marked increase in MPO-specific 3-chlorotyrosine and 3-nitrotyrosine content in HDL in RA subjects consistent with specific targeting of HDL, with increased nitration in RA subjects with CVD. Cholesterol efflux capacity was diminished in RA subjects and correlated inversely with HDL 3-chlorotyrosine suggesting a mechanistic role for MPO. Nitrated HDL was elevated in RACVD subjects compared with RA subjects without CVD. Oxidative peptide mapping revealed site-specific unique oxidation signatures on apoA-1 for RA subjects with and without CVD.. We report an increase in MPO-mediated HDL oxidation that is regiospecific in RA and accentuated in those with CVD. Decreased cholesterol efflux capacity due to MPO-mediated chlorination is a potential mechanism for atherosclerosis in RA and raises the possibility that oxidant resistant forms of HDL may attenuate this increased risk.

Topics: Adult; Aged; Apolipoprotein A-I; Arthritis, Rheumatoid; Cardiovascular Diseases; Case-Control Studies; Cholesterol; Female; Halogenation; Humans; Lipoproteins, HDL; Male; Middle Aged; Oxidation-Reduction; Peptide Mapping; Peroxidase; Tandem Mass Spectrometry; Tyrosine

High myeloperoxidase (MPO) serum levels have been shown in several inflammatory diseases, including rheumatoid arthritis (RA). However, the correlation between MPO levels and disease activity in RA patients is still controversial. The aim of the study was to determine MPO plasma levels in RA patients and to investigate potential correlations between MPO levels and disease activity and treatment. MPO plasma levels were measured by ELISA according the manufacturer's instructions. Disease activity was measured by DAS28 ESR and DAS28 CRP scores, and patients were classified into 4 groups: group 1 DAS28 < 2.6; group 2: 2.6 ≤ DAS28 ≤ 3.2; group 3: 3.2 < DAS28 ≤ 5.1 and group 4: DAS28 > 5.1. Rheumatoid factor (RF) was measured by latex agglutination test, and anti-cyclic citrullinated peptide (anti-CCP) antibodies were detected by ELISA with a commercial kit. Fifty-seven female RA patients (mean age: 46.02 ± 13.47 years, mean disease duration: 115.77 ± 99.44 months) and sixty gender- and age-paired healthy controls were included. Mean MPO plasma levels were significantly higher in patients than in controls (72.27 pM vs. 40.78 pM, P = 0.007). RF was found in 59.6% and anti-CCP in 80.7% of the RA patients. No significant difference in MPO levels was seen among the four RA disease activity groups. We did not find significant correlation between MPO levels and disease activity as measured by DAS28 score. In conclusion, we observed significantly higher MPO plasma levels in RA patients when compared to healthy controls. However, we did not find correlation between MPO plasma level and disease activity.

Topics: Adult; Analysis of Variance; Arthritis, Rheumatoid; Autoantibodies; Biomarkers; Blood Sedimentation; Brazil; C-Reactive Protein; Case-Control Studies; Enzyme-Linked Immunosorbent Assay; Female; Humans; Latex Fixation Tests; Male; Middle Aged; Peptides, Cyclic; Peroxidase; Predictive Value of Tests; Rheumatoid Factor; Severity of Illness Index; Up-Regulation

Reverse cholesterol transport (RCT) is a major antiatherogenic function of high density lipoprotein (HDL). In the current work, the authors evaluated whether the RCT capacity of HDL from rheumatoid arthritis (RA) patients is impaired when compared to healthy controls.. HDL was isolated from 40 patients with RA and 40 age and sex matched healthy controls. Assays of cholesterol efflux, HDL's antioxidant function and paraoxanase-1 (PON-1) activity were performed as described previously. Plasma myeloperoxidase (MPO) activity was assessed by a commercially available assay.. Mean cholesterol efflux capacity of HDL was not significantly different between RA patients (40.2% ± 11.1%) and controls (39.5% ± 8.9%); p=0.75. However, HDL from RA patients with high disease activity measured by a disease activity score using 28 joint count (DAS28>5.1), had significantly decreased ability to promote cholesterol efflux compared to HDL from patients with very low disease activity/clinical remission (DAS28<2.6). Significant correlations were noted between cholesterol efflux and the DAS28 (r=-0.39, p=0.01) and erythrocyte sedimentation rate, (r=-0.41, p=0.0009). Higher plasma MPO activity was associated with worse HDL function (r=0.41/p=0.009 (antioxidant capacity); r=0.35, p=0.03 (efflux)). HDL's ability to promote cholesterol efflux was modestly but significantly correlated with its antioxidant function (r=-0.34, p=0.03).. The cholesterol efflux capacity of HDL is impaired in RA patients with high disease activity and is correlated with systemic inflammation and HDL's antioxidant capacity. Attenuation of HDL function, independent of HDL cholesterol levels, may suggest a mechanism by which active RA contributes to increased cardiovascular (CV) risk.

Topics: Animals; Antioxidants; Antirheumatic Agents; Apolipoprotein A-I; Arthritis, Rheumatoid; Aryldialkylphosphatase; Cell Line; Cholesterol; Female; Humans; Joints; Lipoproteins, HDL; Macrophages; Male; Mice; Middle Aged; Peroxidase; Remission Induction

The treatment of some inflammatory diseases, such as rheumatoid arthritis, remains an important target for studies because some patients are refractory to conventional treatment. Mycophenolate mofetil (MMF), an immunosuppressive drug, has been shown to have a beneficial effect on the therapy of inflammatory and autoimmune diseases. In the present study, we aimed to analyse the anti-inflammatory effect of MMF administered by oral route in the mouse carrageenan-induced air pouch model.. MMF significantly inhibited the influx of leukocytes, exudate concentrations (P<0.01), activities of myeloperoxidase (MPO) and adenosine deaminase (ADA), levels of nitrite/nitrate (NO(x)) and inducible nitric oxide synthase (iNOS) mRNA expression, as well as the levels of mRNA expression and proteins of tumor necrosis factor-alpha (TNF-α), Interleukin-beta (IL-1β) and vascular endothelial growth factor-alpha (VEGF-α) (P<0.05). These results provide evidence that MMF has an important anti-inflammatory effect in reducing the influx of leukocytes and exudate concentrations. These inhibitory effects are correlated with the inhibition of specific pro-inflammatory enzymes (MPO, ADA and iNOS), and the levels of mRNA expression and proteins of TNF-α, IL-1β and VEGF-α.

Topics: Administration, Oral; Animals; Anti-Inflammatory Agents, Non-Steroidal; Arthritis, Rheumatoid; Carrageenan; Cell Movement; Cytokines; Disease Models, Animal; Humans; Immunosuppression Therapy; Inflammation Mediators; Leukocytes; Mice; Mycophenolic Acid; Nitric Oxide; Peroxidase; Vascular Endothelial Growth Factor A

To determine whether MPO contributes to oxidative stress and disease activity in RA and whether it produces hypochlorous acid in SF.. Plasma and where possible SF were collected from 77 RA patients while 120 healthy controls supplied plasma only. MPO and protein carbonyls were measured by ELISAs. 3-Chlorotyrosine in proteins and allantoin in plasma were measured by mass spectrometry.. Plasma MPO concentrations were significantly higher in patients with RA compared with healthy controls [10.8 ng/ml, inter-quartile range (IQR): 7.2-14.2; P<0.05], but there was no significant difference in plasma MPO protein concentrations between RA patients with high disease activity (HDA; DAS-28 >3.2) and those with low disease activity (LDA; DAS-28 ≤ 3.2) (HDA 27.9 ng/ml, 20.2-34.1 vs LDA 22.1 ng/ml, 16.9-34.9; P>0.05). There was a significant relationship between plasma MPO and DAS-28 (r=0.35; P=0.005). Plasma protein carbonyls and allantoin were significantly higher in patients with RA compared with the healthy controls. MPO protein was significantly higher in SF compared with plasma (median 624.0 ng/ml, IQR 258.4-2433.0 vs 30.2 ng/ml, IQR 25.1-50.9; P<0.0001). The MPO present in SF was mostly active. 3-Chlorotyrosine, a specific biomarker of hypochlorous acid, was present in proteins from SF and related to the concentration of MPO (r=0.69; P=0.001). Protein carbonyls in SF were associated with MPO protein concentration (r=0.40; P=0.019) and 3-chlorotyrosine (r=0.66; P=0.003).. MPO is elevated in patients with RA and promotes oxidative stress through the production of hypochlorous acid.

Topics: Adult; Aged; Aged, 80 and over; Arthritis, Rheumatoid; Female; Humans; Male; Middle Aged; Oxidative Stress; Peroxidase; Reactive Oxygen Species; Synovial Fluid

Antineutrophil cytoplasmic antibodies (ANCAs) against myeloperoxidase (MPO), proteinase 3 (PR-3), lactoferrin (LF), cathepsin G (CG) and elastase (EL) were determined to investigate whether the presence of ANCAs is closely related to extra-articular manifestations in Japanese patients with rheumatoid arthritis (RA). Antibodies against MPO, PR-3, LF, CG and EL were determined in sera from 125 patients with RA and 83 sera from patients with other rheumatic diseases by enzyme-linked immunosorbent assay. Clinical manifestations and laboratory parameters of the patients were studied from medical records. Thirty of the 125 (24.0%) RA patients were positive for ANCAs for at least one of these 5 ANCA antigens. Among the 5 ANCAs, anti-LF antibody (anti-LF) (16.8%) was most commonly observed in patients with RA. A higher joint score (JS) and an elevated ESR were demonstrated in ANCA-positive RA patients compared to those of ANCA-negative patients (40.8 ± 43.3, 24.3 ± 26.2, p < 0.05, 44.4 ± 22.4, 28.9 ± 23.6, p < 0.05, respectively). No statistical differences in the presence of interstitial pneumonia, cutaneous vasculitis, rheumatoid nodules and mononeuropathy multiplex were observed between ANCA-positive and ANCA-negative patients. The presence of anti-LF is expected to be of pathological relevance, as the action of anti-LF towards LF results in the inhibition of the anti-inflammatory activity of LF.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Arthrography; Biomarkers; Cathepsin G; Enzymes; Female; Humans; Joints; Lactoferrin; Male; Middle Aged; Myeloblastin; Pancreatic Elastase; Peroxidase; Vasculitis; Young Adult

A new group of autoantibodies in Rheumatoid Arthritis (RA), the anti-cyclic citrullinated peptide (anti-CCP) antibodies directed to citrulline-containing proteins, which are of value for the severity of RA. Up to date, the relationship between anti-CCP antibodies and oxidant, anti-oxidant activity in patients with RA has not been elucidated in the previous studies. In this study we aimed to investigate the effect of anti-CCP antibodies in the circulation on whole blood, serum and synovial fluid oxidant and anti-oxidant activity in patients with RA.. RA patients with anti-CCP (+) (n=25) and anti-CCP (-) (n=24) were recruited into the study. All patients had a positive rheumatoid factor (RF). The patients who were under treatment with only non-steroidal antiinflammatory drugs (NSAID) at the study time included in the study. Catalase (CAT), Glutathione peroxidase (GSHPx), Myeloperoxidase (MPO) activities and the levels of Malondialdehyde (MDA) were measured in whole blood, serum and synovial fluid in both groups.. There were no significant differences in terms of the mean whole blood and serum antioxidative activity (CAT, GSHpx) and the mean blood and serum MDA and MPO values (oxidative activity), between the patients with anti-CCP(+) and those with anti-CCP(-). There was increased synovial oxidant activity (MDA and MPO levels) (p<0.05) in anti-CCP(+) RA patients with or without ESR negativity when compared with anti-CCP(-) RA patients. There was positive correlation between anti-CCP antibody levels and synovial MDA and MPO levels (r=0.435, p<0.05, r=0.563, p<0.05 respectively) in anti-CCP (+) group.. In conclusion, anti-CCP antibody positivity seems to be associated with increased synovial fluid oxidant activity (increased MDA and MPO levels) in patients with RA. These conclusions need to be validated in a larger controlled study population.

Topics: Adult; Antibodies; Antioxidants; Arthritis, Rheumatoid; Catalase; Enzyme-Linked Immunosorbent Assay; Female; Glutathione Peroxidase; Humans; Male; Malondialdehyde; Middle Aged; Peptides, Cyclic; Peroxidase

To determine serum antibody against human and bacterial heat shock protein (HSP) 60/70 in myeloperoxidase (MPO)-specific anti-neutrophil cytoplasmic autoantibody (ANCA) positive microscopic polyangiitis (MPA), 58 patients with MPO-ANCA positive MPA, 48 with RA (rheumatoid arthritis) and 40 with SLE (systemic lupus erythematosus) were studied. Serum antibodies against HSP (human HSP 70, human HSP 60, Mycobacterium HSP 70, and Escherichia coli HSP 60) were measured by sandwich ELISA. The frequency of anti-human HSP 60/70 antibody positive patients was significantly greater in MPO-ANCA positive MPA than SLE and healthy controls. Anti-human HSP 60/70 antibody titers in patients with MPO-ANCA positive MPA were significantly higher than those of healthy controls; anti-bacterial HSP 60/70 antibody titers were also higher. There was a significant correlation between titers of anti-human HSP 70 antibody and anti-Mycobacterium HSP 70 antibody. A correlation was also found between titers of anti-human HSP 70 antibody and anti-human HSP 60 antibody. Anti-human and bacterial HSP 60/70 antibody titers changed in parallel with disease activity in patients with antibody positive MPA. The anti-HSP antibody titer was also increased in patients with RA and SLE. These results suggest that an immunological background via anti-HSP 60/70 antibodies might be associated with pathogenesis in MPO-ANCA positive MPA.

Topics: Aged; Aged, 80 and over; Arthritis, Rheumatoid; Autoantibodies; Chaperonin 60; Enzyme-Linked Immunosorbent Assay; Escherichia coli; Female; HSP70 Heat-Shock Proteins; Humans; Lupus Erythematosus, Systemic; Male; Microscopic Polyangiitis; Middle Aged; Mycobacterium; Neutrophils; Peroxidase

Topics: Aged; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Antibodies, Antineutrophil Cytoplasmic; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Arthritis, Rheumatoid; Drug Substitution; Female; Glomerulonephritis, IGA; Humans; Immunosuppressive Agents; Injections, Intravenous; Kidney Glomerulus; Peroxidase; Remission Induction; Treatment Outcome

A dietary link to rheumatoid arthritis (RA) has been suspected and an influence on arthritic symptoms by different diets has been reported. Our primary aim was to record the self-experienced adverse food reactions in patients with RA. A secondary aim was to relate self-experienced adverse reactions to dairy produce and wheat to the local mucosal reactivity observed after rectal challenge with cow's milk protein (CM) and wheat gluten.. A questionnaire about self-experienced adverse reaction to food was sent to 347 RA patients. Rectal challenge with CM and gluten was performed in 27 of these patients and in healthy controls (n = 18). After a 15-h challenge the mucosal production of nitric oxide (NO) and the mucosal release of myeloperoxidase (MPO) and eosinophil cationic protein (ECP) were measured by using the mucosal patch technique.. Twenty-seven per cent of the RA patients reported food intolerance (FI) to various foods, and in particular to CM, meat, and wheat gluten. Strong mucosal reactivity to CM was observed in 11% of the patients. Moderately increased mucosal reactivity to CM and gluten was found in 22% and 33%, respectively, of the patients. No relationship was found between self-experienced adverse reactions to CM or gluten and mucosal reactivity to these proteins.. Perceived FI is reported frequently by RA patients, with a prevalence similar to that reported previously in the general population. Mucosal reactivity to CM and gluten is seen in a minor fraction of RA patients and is not related to the frequently perceived intolerance to these proteins.

Topics: Administration, Rectal; Adult; Arthritis, Rheumatoid; Female; Glutens; Humans; Immunoglobulin A; Immunoglobulin G; Male; Middle Aged; Milk Hypersensitivity; Milk Proteins; Mucous Membrane; Nitric Oxide; Patch Tests; Peroxidase; Rectum; Severity of Illness Index; Statistics, Nonparametric; Surveys and Questionnaires; Wheat Hypersensitivity

HE3286 (17alpha-ethynyl-5-androstene-3beta, 7beta, 17beta-triol) is an orally bio-available synthetic derivative of naturally occurring androstene-3beta, 7beta, 17beta-triol. Our present data show that oral treatment with HE3286, favourably influenced the course of arthritis in the rat model of adjuvant-induced arthritis (reduced cumulative disease scores and paw edema), and in the mouse model of collagen antibody-induced arthritis (reduced clinical paw scores). Importantly, HE3286 was not immune suppressive in human mixed lymphocyte reaction or in animals challenged with Coxsackie B3 virus. HE3286 is currently in phase I/II clinical trials in rheumatoid arthritis and ulcerative colitis and these findings further strengthen the possibility that HE3286 may represent an effective anti-inflammatory agent useful for treating chronic inflammation with a more attractive safety profile than glucocorticoids or cyclooxygenase inhibitors.

Topics: Administration, Oral; Animals; Arthritis, Experimental; Arthritis, Rheumatoid; Body Weight; Dehydroepiandrosterone; Disease Models, Animal; Disease Progression; Enterovirus B, Human; Humans; Immunization; Interleukin-6; Lymphocyte Culture Test, Mixed; Male; Mice; Myocarditis; Organ Size; Peroxidase; Rats; Time Factors; Tumor Necrosis Factor-alpha

Bacopa monniera (L.) Wettst is an Ayurvedic herb with antirheumatic potential. This study investigated the therapeutic efficacy of Bacopa monniera in treating rheumatoid arthritis using a type II collagen-induced arthritis rat model. Arthritis was induced in male Wistar rats by immunization with bovine type II collagen in complete Freund's adjuvant. Bacopa monniera extract (BME) was administered after the development of arthritis from day 14 onwards. The total duration of experiment was 60 days. Paw swelling, arthritic index, inflammatory mediators such as cyclooxygenase, lipoxygenase, myeloperoxidase and serum anti-collagen IgG and IgM levels were analysed in control and experimental rats. Arthritic induction significantly increased paw edema and other classical signs of arthritis coupled to upregulation of inflammatory mediators such as cyclooxygenase, lipoxygenase, neutrophil infiltration and increased anti-collagen IgM and IgG levels in serum. BME significantly inhibited the footpad swelling and arthritic symptoms. BME was effective in inhibiting cyclooxygenase and lipoxygenase activities in arthritic rats. Decreased neutrophil infiltration was evident from decreased myeloperoxidase activity and histopathological data where an improvement in joint architecture was also observed. Serum anti-collagen IgM and IgG levels were consistently decreased. Thus the study demonstrates the potential antiarthritic effect of Bacopa monniera for treating arthritis which might confer its antirheumatic activity.

Topics: Animals; Antirheumatic Agents; Arthritis, Experimental; Arthritis, Rheumatoid; Bacopa; Cattle; Collagen Type II; Disease Models, Animal; Edema; Immunoglobulin G; Immunoglobulin M; Inflammation Mediators; Joints; Lipoxygenase; Male; Neutrophil Infiltration; Peroxidase; Phytotherapy; Plant Extracts; Prostaglandin-Endoperoxide Synthases; Rats; Rats, Wistar; Severity of Illness Index; Up-Regulation

We report on a 33-year-old woman who presented with positive myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) during rheumatoid arthritis treatment with infliximab. She had a history of worsening arthralgia, and urinalysis showed the new occurrence of hematuria and proteinuria. Renal biopsy showed necrotizing crescentic glomerulonephritis. Immunosuppressive therapy and discontinuation of the infliximab therapy alleviated her arthralgia and improved the urinalysis results. We report this rare case in which an anti-tumor necrosis factor-α (TNF-α) agent for ANCA-associated systemic vasculitis was studied.

Topics: Administration, Oral; Adult; Antibodies, Antineutrophil Cytoplasmic; Antibodies, Monoclonal; Antirheumatic Agents; Arthritis, Rheumatoid; Drug Substitution; Female; Glucocorticoids; Humans; Infliximab; Injections, Intravenous; Kidney; Kidney Diseases; Methylprednisolone; Peroxidase; Prednisolone; Treatment Outcome; Tumor Necrosis Factor-alpha; Vasculitis

To characterize the antiinflammatory function of high-density lipoprotein (HDL) in patients with rheumatoid arthritis (RA) and to identify specific differences in HDL-associated proteins and enzymes that distinguish proinflammatory HDL from normal, antiinflammatory HDL.. We studied 132 RA patients. The antiinflammatory function of HDL was assessed by a cell-free assay, and proinflammatory HDL was defined by an HDL inflammatory index > or =1. Plasma and HDL-associated protein levels of apolipoprotein A-I (Apo A-I), haptoglobin, hemopexin, hemoglobin, and myeloperoxidase (MPO) were measured by direct and sandwich enzyme-linked immunosorbent assays, respectively. Lecithin:cholesterol acyltransferase (LCAT) activity was measured by a commercially available assay.. Age, disease activity, the presence of erosive disease, non-Caucasian race, and smoking were significantly associated with proinflammatory HDL on multivariate analysis. Patients with proinflammatory HDL had higher measures of systemic inflammation, and a significant correlation was observed between RA disease activity (using the Disease Activity Score in 28 joints) and the HDL inflammatory index (r = 0.54, P < 0.0001). Compared with patients with antiinflammatory HDL, patients with proinflammatory HDL had significantly higher levels of haptoglobin, hemoglobin, Apo A-I, and MPO associated with HDL (P < 0.05 for all comparisons except MPO, which was P = 0.05). LCAT activity was lowest in patients with proinflammatory HDL, but was also significantly reduced in RA patients with antiinflammatory HDL as compared with healthy controls (P = 0.001).. Proinflammatory HDL in this RA patient cohort was associated with active disease and an altered protein cargo as compared with antiinflammatory HDL in RA patients and in healthy controls. The antiinflammatory function of HDL was inversely correlated with systemic inflammation in RA patients and may warrant further investigation as a mechanism by which active RA increases cardiovascular morbidity and mortality.

Topics: Adult; Aged; Antirheumatic Agents; Apolipoprotein A-I; Arthritis, Rheumatoid; Case-Control Studies; Cohort Studies; Cross-Sectional Studies; Female; Haptoglobins; Hemoglobins; Hemopexin; Humans; Lipoproteins, HDL; Male; Methotrexate; Middle Aged; Peroxidase; Phosphatidylcholine-Sterol O-Acyltransferase; Severity of Illness Index

Rheumatoid arthritis (RA) is an inflammatory disease associated with premature atherosclerosis. We hypothesized that mediators of inflammation associated with atherosclerosis in other populations (interleukin-6 [IL-6], tumor necrosis factor alpha [TNFalpha], serum amyloid A [SAA], vascular endothelial growth factor, neutrophil count, IL-1alpha, E-selectin, intercellular adhesion molecule 1 [ICAM-1], myeloperoxidase [MPO], matrix metalloproteinase 9, and vascular cell adhesion molecule 1) would be increased and associated with the severity of coronary atherosclerosis in patients with RA.. Clinical variables, concentrations of inflammatory mediators, and coronary artery calcification were measured in 169 patients with RA and 92 control subjects. Differences in concentrations of inflammatory mediators were compared using median quantile regression. The relationship of inflammatory mediators with the severity of coronary calcification in RA and control subjects was examined using proportional odds logistic regression, allowing for interaction with disease status. Models were adjusted for traditional cardiovascular risk factors.. Median serum concentrations of IL-6, SAA, ICAM-1, E-selectin, TNFalpha, and MPO and peripheral blood neutrophil count were higher in patients with RA than controls (all P < 0.05), independent of Framingham risk score and diabetes mellitus (DM). IL-6 (main effect odds ratio [OR] 1.72; 95% confidence interval [95% CI] 1.12, 2.66) and TNFalpha (main effect OR 1.49; 95% CI 1.16, 1.90) concentrations were significantly associated with higher amounts of coronary calcium, independent of Framingham risk score and DM, and such main effects significantly differed from controls (P = 0.001 and 0.03 for interaction, respectively).. TNFalpha and IL-6 are significantly associated with the severity of subclinical atherosclerosis, independent of Framingham risk score, in RA.

Topics: Adult; Age of Onset; Aged; Arthritis, Rheumatoid; Biomarkers; Coronary Artery Disease; E-Selectin; Female; Humans; Inflammation Mediators; Intercellular Adhesion Molecule-1; Interleukin-1alpha; Interleukin-6; Logistic Models; Male; Matrix Metalloproteinase 9; Middle Aged; Neutrophils; Peroxidase; Risk Factors; Serum Amyloid A Protein; Tumor Necrosis Factor-alpha; Vascular Endothelial Growth Factor A

Increased numbers of neutrophils expressing proteinase 3 on their membrane (mPR3) have been reported in anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) and are suggested to be involved in AAV immunopathogenesis. In most studies, neutrophils were analysed for mPR3 expression without priming with TNFalpha, suggesting that mPR3 expression on neutrophils is dependent on other priming events, such as isolation procedures . These priming events can be variable. Therefore, we analysed mPR3 expression on neutrophils before and after priming with TNFalpha to assess whether standardised assessment of mPR3 expression requires priming. Using neutrophils before and after priming with TNFalpha, we assessed percentages of mPR3(+) neutrophils in patients with AAV and in disease and healthy controls.. Neutrophils from patients with PR3-AAV and MPO-AAV, systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), and from healthy controls were analysed before and after priming with TNFalpha for mPR3 expression.. 42% of all individuals analysed showed minimal expression for mPR3 on all neutrophils before priming with TNFalpha, whereas after priming a clear mPR3(+) subset was observed next to mPR3(-) neutrophils, corresponding to bimodal mPR3 expression. In patients with PR3-AAV or MPO-AAV, the percentage of mPR3(+) neutrophils after priming with TNFalpha was significantly increased (p<0.01 and p<0.05, respectively) compared with healthy controls. Percentages of mPR3(+) PMN were also increased in patients with SLE (p<0.01) but not in RA.. Standardised assessment of proteinase 3 on the membrane of neutrophils requires priming with TNFalpha. Percentages of mPR3(+) PMN are increased in AAV and SLE, but not in RA.

Topics: Adult; Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Biomarkers; Cell Membrane; Female; Humans; Lupus Erythematosus, Systemic; Male; Middle Aged; Myeloblastin; Neutrophil Activation; Neutrophils; Peroxidase; Receptors, Complement 3b; Receptors, Tumor Necrosis Factor; Tumor Necrosis Factor-alpha; Vasculitis

Proteinase 3 (PR3), a serine proteinase contained in neutrophil azurophilic granules, is considered a risk factor for vasculitides and rheumatoid arthritis when expressed on the outer leaflet of neutrophil plasma membrane and is the preferred target of antineutrophil cytoplasm autoantibodies (ANCA) in Wegener granulomatosis. ANCA binding to PR3 expressed at the surface of neutrophils activates them. Evidence is provided that neutrophil apoptosis induced significantly more membrane PR3 expression without degranulation (but no enhanced membrane CD35, CD66b, CD63, myeloperoxidase, or elastase expression). This observation was confirmed on cytoplasts, a model of granule-free neutrophils. We hypothesized that PR3 could interact with proteins involved in membrane flip-flop (eg, phospholipid scramblase 1 [PLSCR1]). PR3-PLSCR1 interaction in neutrophils was demonstrated by confocal microscopy and coimmunoprecipitation. In the RBL-2H3 rat mast-cell line stably transfected with PR3 or its inactive mutant (PR3S203A), PR3 externalization depended on PLSCR1, as shown by less PR3 externalization in the presence of rPLSCR1 siRNA, but independently of its serine-proteinase activity. Finally, apoptosis-externalized PR3 decreased the human macrophage-phagocytosis rate of apoptotic PR3 transfectants. Therefore, in addition to ANCA binding in vasculitis, the proinflammatory role of membrane PR3 expression may involve interference with macrophage clearance of apoptotic neutrophils.

Topics: Animals; Antibodies, Antineutrophil Cytoplasmic; Antigens, CD; Apoptosis; Arthritis, Rheumatoid; Cell Line; Cell Membrane; Gene Expression Regulation, Enzymologic; Granulomatosis with Polyangiitis; Humans; Macrophages; Mast Cells; Mutation; Myeloblastin; Neutrophil Activation; Neutrophils; Pancreatic Elastase; Peroxidase; Phagocytosis; Phospholipid Transfer Proteins; Protein Transport; Rats; Risk Factors; RNA, Small Interfering; Secretory Vesicles; Vasculitis

Autoantibodies to myeloperoxidase (MPO) are a subset of anti-neutrophil cytoplasmic antibody (ANCA, MPO-ANCA) detected in the sera of some patients with primary systemic vasculitis. The titer of MPO-ANCA does not always reflect disease activity and this inconsistency may be attributable to differences in epitopic specificity by MPO-ANCA among various patients with vasculitis. Epitope analysis may also explain the occurrence of MPO-ANCA in different vasculitic syndromes. We screened the sera of 148 MPO-ANCA positive patients from six vasculitic syndromes: rapidly progressive gromerulonephritis (RPGN), microscopic polyangiitis (MPA), idiopathic crescentic glomerulonephritis (I-CrGN), classic polyangiitis nodosa (cPAN), Churg-Strauss syndrome (CSS), Kawasaki disease (KD); and from patients with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). The sera were collected by the Intractable Vasculitis Research Project Group in Japan. No serum showed epitopes La and Lb of light chain of MPO, and sera with 68.6% of patients showed a positive reaction to one or more epitopes in heavy chain of MPO. Analysis of binding level showed that RPGN, I-CrGN and MPA sera mainly reacted to the Ha epitope at the N-termimus of the MPO heavy chain, CSS sera reacted to Ha and the Hf epitope close to the C-terminus of the MPO heavy chain, KD reacted mainly to Hf, while SLE and RA sera reacted to all epitopes. These results suggest that MPO-ANCA recognizing specific regions of the N-terminus of the MPO H-chain confer an increased risk of vasculitis RPGN, I-CrGN, MPA and CSS. Furthermore, the epitopic specificity of MPO-ANCA differentiates vasculitic from non-vasculitic syndromes associated with MPO-ANCA positivity and differentiates in the cirtain type of vasculitis from various vasculitic syndromes. In particular, vasculitic syndromes associated with kidney involvement had similar epitopic reactivity which suggests that this pattern confers an increased risk of vasculitis.

Topics: Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Autoantibodies; Epitope Mapping; Glomerulonephritis; Humans; Japan; Lupus Erythematosus, Systemic; Mucocutaneous Lymph Node Syndrome; Peroxidase; Risk Factors; Vasculitis

Rheumatoid arthritis (RA) is a diffuse connective tissue disease and a multi-system disorder with inflammatory process affecting joints in the first place. RA is found in 1 to 3% of population; the first signs of it are usually found in people aged 35 to 50. Neurological pathology in RA is manifested by cervicocranialgia, cervical myelopathy, pathological changes in the upper cervical spine, and cerebral disorders. However, exact mechanisms of the development of central nervous system (CNS) lesions in RA have not been presented. The aim of this study was to clarify the pathophysiological mechanisms and clinical peculiarities of cerebral disturbances in RA. The subjects were 42 female patients, who underwent clinical, neurological, clinicolaboratory, immunological, and clinicophysiological examination. Subjective and objective symptoms were studied; the following syndromes of CNS pathology were distinguished: initial manifestations of cerebral functional insufficiency; disseminated cerebral micro symptoms; focal cerebral lesion. These disorders were accompanied by changes in biochemical parameters which evidenced the presence of connective tissue destruction and immune inflammation. Immunological tests revealed elevation of the level of myelin basic protein antibodies, which correlated with the degree of neurological disturbances and the duration of the disease. The level of myeloperoxidase was elevated, but the degree of this elevation did not depend on the degree of the cerebral disorder and displayed a negative correlation with the duration of the disease. The results of the study demonstrate primary lesion of small vessels in RA--secondary vasculitis followed by demyelinization of CNS white substance. Thus, three forms of cerebrovascular pathology, caused by acute or chronic cerebral vascular insufficiency in RA can be distinguished: initial manifestations of cerebral circulation insufficiency; discirculatory encephalopathy; transient cerebral circulation disturbances and cerebral stroke.

Topics: Adult; Aged; Antibodies; Arthritis, Rheumatoid; Cerebrovascular Disorders; Cervical Vertebrae; Electroencephalography; Female; Humans; Male; Middle Aged; Myelin Basic Protein; Neuralgia; Peroxidase

To determine the frequency of antithyroid antibodies and the presence of autoimmune thyroiditis among patients with primary Sjögren's syndrome.. A case-control study.. 53 consecutive patients with primary Sjögren's syndrome, 30 with rheumatoid arthritis, 12 with secondary Sjögren's syndrome associated with rheumatoid arthritis, 17 with autoimmune thyroiditis, and 53 apparently healthy controls were studied for anti-TG and anti-TPO antibodies as well as serum thyroid hormones and TSH levels.. The overall frequencies of thyroid antibodies were 6/53 (11%) in primary Sjögren's syndrome, 2/30 (7%) in rheumatoid arthritis, 2/12 (17%) in secondary Sjögren's syndrome, 4/53 (8%) in healthy controls, and 16/17 (94%) in autoimmune thyroiditis. There was no difference in the frequency of the thyroid antibodies among the groups if patients with autoimmune thyroiditis were excluded (p = 0.415 for anti-TPO; p = 0.275 for anti-TG; p = 0.696 for either anti-TG and/or anti-TPO). Only two patients with primary Sjogren's syndrome had clinical hypothyroidism associated with autoimmune thyroiditis.. In this Turkish population, no association between primary Sjögren's syndrome and autoimmune thyroiditis was found.

Topics: Adult; Antibodies; Arthritis, Rheumatoid; Case-Control Studies; Female; Humans; Male; Middle Aged; Peroxidase; Sjogren's Syndrome; Thyroglobulin; Thyroiditis, Autoimmune

To investigate platelets and different inflammatory markers in conjunction with a substantial inflammatory reaction. We used individuals with active rheumatoid arthritis (RA) as an experimental cohort.. We selected 16 patients with active RA having at least one affected joint. On day 1, platelet and neutrophil counts together with C-reactive protein (CRP) were determined. We further analysed platelet volume (MPV) and plasma levels of thrombopoietin (TPO), P-selectin, myeloperoxidase and interleukin 6 (IL-6). After 2 years when all patients failed to show any swollen joints all analyses were repeated.. As expected platelet count, CRP and IL-6 were elevated in active RA. The measures correlated with each other thus reflecting the same characteristic of the inflammatory response. The neutrophil count, MPV and myeloperoxidase also mirror disease activity. They failed to correlate with other activity markers thus providing unique information. MPV and myeloperoxidase on day 1 correlated with recovery values. Therefore, they could be suitable to use when following the inflammatory reaction over a long period of time.

Topics: Arthritis, Rheumatoid; Biomarkers; Blood Platelets; C-Reactive Protein; Cell Size; Female; Humans; Inflammation; Interleukin-6; Leukocyte Count; Male; Middle Aged; P-Selectin; Peroxidase; Platelet Count

To determine the prevalence and the associations of anti-neutrophil cytoplasmic antibodies (ANCA) and subtypes with clinical, biological, and radiological findings in patients with rheumatoid arthritis (RA).. This is a transversal study of 85 patients with RA (followed in Ibn-i Sina Hospital, Ankara University School of Medicine) with disease duration of 8.7 +/- 6.4 years. Besides clinical, biological, and radiological disease activity parameters, ANCA and ANCA against myeloperoxidase (MPO) and proteinase 3 (PR3) were examined.. The prevalence of ANCA, perinuclear ANCA (p-ANCA) and atypical ANCA (a-ANCA) were 18% (15/85 patients), 6% and 12%, respectively. Anti-MPO was found in six patients while anti-PR3 was not found. No significant association could be found between clinical, biological, and radiological disease activity assessments and ANCA (including indirect immunoflorescence subtypes). Similarly, ANCA were not associated with features suggestive of underlying vasculitis (noticed in 11/85 patients), and/or other extra-articular features.. Our results confirm that ANCA of various specificities (mainly a-ANCA) occur in a minority of RA. However, those ANCA were not associated with more severe RA, including the 6/85 patients positive for MPO (who were all free from vasculitis). The over-representation in RA sera of a-ANCA, as compared to p-ANCA, should be further studied.

Topics: Adult; Antibodies, Antineutrophil Cytoplasmic; Antibody Specificity; Arthritis, Rheumatoid; Female; Fluorescent Antibody Technique, Indirect; Humans; Male; Middle Aged; Peroxidase

The objective of the present study was to analyse salivary gland and free radical involvement in rheumatoid arthritis (RA).. Thirty-four consenting RA patients (rheumatoid factor-positive) and 18 healthy controls, matched in age and gender, participated in the study. Plasma and saliva samples were harvested and subjected to compositional analysis and various free radical-related tests.. The mean salivary flow rate was lower in the RA patients than in the control group, whereas all plasma and salivary antioxidants were increased. Mean values of plasma malondialdehyde and ceruloplasmin were higher in the RA patients.. The effects of RA on salivary gland flow rates and antioxidant compositional parameters may be of great importance for the further elucidation of the role of free radicals in RA pathogenesis and for its general diagnosis and evaluation. The demonstrated correlation between the altered salivary parameters and the severity of the disease may indicate that evaluation of the salivary status of RA patients is warranted.

Topics: Adult; Age Distribution; Antioxidants; Arthritis, Rheumatoid; Ceruloplasmin; Female; Humans; Male; Malondialdehyde; Middle Aged; Oxidative Stress; Peroxidase; Saliva; Salivation; Severity of Illness Index; Sex Distribution; Uric Acid

We report a rare case of nephrotic syndrome in an elderly woman with positive antineutrophil cytoplasmic antibody(ANCA). The patient was 81 years of age and had a history of interstitial pneumonia. She was diagnosed rheumatoid arthritis(RA) at admission. Rapidly progressing renal damage was found with mild microscopic hematuria and positive ANCA. The renal biopsy findings indicated membranous nephropathy. Neither gold nor anti-rheumatic drugs had been previously administered. She may have had an RA-specific membranous nephropathy. Crescentic formation was not clear. With hematuria, the leukocyte infiltration in the capillary lumen and the change in epithelial cells of Bowman's capsules would be histological findings suggesting ANCA-associated nephritis. This is a rare report on membranous nephropathy in an RA patient with ANCA-associated nephritis.

Topics: Aged; Aged, 80 and over; Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Female; Glomerulonephritis, Membranous; Humans; Kidney; Meningitis, Cryptococcal; Peroxidase; Prednisolone; Treatment Outcome

Macrophages have been described as 'factories' of pro-inflammatory cytokines. Several years ago the present investigators reported that binding of inactive myeloperoxidase (iMPO) to the macrophage-mannose receptor resulted in the induction of TNF and other cytokines. Also, if endothelial cells were incubated with iMPO, but not enzymatically active myeloperoxidase (MPO), upregulation of cytokine mRNA and cytokines was observed. Taken in their entirety, the data suggest a dichotomy of function for myeloperoxidase; that is, enzymatically active MPO functions primarily in cell killing through the 'cytotoxic triad' and iMPO functions as an immunoregulatory molecule through the induction of numerous cytokines. These studies underscore a previously unrecognized interaction among neutrophils, endothelial cells and macrophages, resulting in the induction of TNF and perpetuation of inflammation. The inflammation induced could be relevant in a number of diseases in which neutrophils play a prominent role. The importance of this interaction in the pathogenesis of rheumatoid arthritis is currently under investigation.

Topics: Arthritis, Rheumatoid; Cell Communication; Cytokines; Humans; Inflammation; Lectins, C-Type; Macrophages; Mannose Receptor; Mannose-Binding Lectins; Models, Biological; Neutrophils; Peroxidase; Receptors, Cell Surface; Signal Transduction

To investigate the prevalence and clinical relevance of immunoglobulin (Ig) isotypes of antimyeloperoxidase (MPO) and antilactoferrin (LF) antibodies in collagen diseases, enzyme-linked immunosorbent assay was employed to detect the Ig isotypes of both antibodies. The purified proteins of MPO and LF were used as two major representative antigens for anti-neutrophil cytoplasmic antibodies (ANCA) with a perinuclear staining pattern by an indirect immunofluorescent technique. We examined 131 serum samples from 79 patients with rheumatoid arthritis (RA), 32 with systemic lupus erythematosus (SLE), 14 with progressive systemic sclerosis (PSS), 6 with polymyositis/dermatomyositis (PM/DM), and 5 with idiopathic crescentic glomerulonephritis who served as positive controls and 36 healthy subjects who served as controls. A limited number of patients with RA (4-10%), SLE (6-9%), and PSS (7-14%) but not PM/DM showed positive IgG or IgA anti-MPO antibody (MPO-ANCA) but not IgM MPO-ANCA. However, 10-20% of RA, 40-60% of SLE, 20-36% of PSS but none of the PM/DM patients showed positive IgG, IgA, or IgM anti-LF antibody (LF-ANCA). MPO- and LF-ANCA positivity in RA patients was correlated with markers of disease activity such as the erythrocyte sedimentation rate, C-reactive protein, and serum Ig levels. IgG LF-ANCA but not MPO-ANCA positivity in SLE patients also was correlated with the disease activity index but not with clinical features. Neither MPO- nor LF-ANCA positivity in PSS patients was correlated with any clinical features. Overall, both MPO- and LF-ANCA were found mainly in RA, SLE, and PSS patients but not in PM/DM patients. The Ig isotypes of MPO- and LF-ANCA frequently belonged to both IgG and IgA and rarely to the IgM class. Both MPO- and LF-ANCA positivity reflected disease activity in RA and SLE rather than specific organ involvement.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Antineutrophil Cytoplasmic; Antibody Specificity; Arthritis, Rheumatoid; Autoantigens; Autoimmune Diseases; Collagen Diseases; Dermatomyositis; Enzyme-Linked Immunosorbent Assay; Female; Glomerulonephritis; Humans; Immunoglobulin A; Immunoglobulin G; Immunoglobulin Isotypes; Immunoglobulin M; Lactoferrin; Lupus Erythematosus, Systemic; Male; Middle Aged; Organ Specificity; Peroxidase; Polymyositis; Scleroderma, Systemic

We present 3 cases of anti-myeloperoxidase, anti-neutrophil cytoplasmic antibody (MPO-ANCA)-positive rapidly progressive glomerulonephritis developed during the treatment with D-penicillamine (D-PC) for rheumatoid arthritis. Rheumatoid arthritis was diagnosed in these patients, and D-PC was administered to them at doses of 100, 200, and 300 mg per day for 32, 42, and 39 months, respectively. They developed proteinuria, hematuria, renal insufficiency, and anemia, and D-PC was stopped. On admission, MPO-ANCA was strongly positive in their sera. Renal biopsy showed glomerulonephritis with cellular crescents. Immunofluorescence examination revealed deposits of granular IgG, IgM, IgA, C1q, and C3 in the mesangium. The 3 patients were treated with steroid pulse therapy along with administration of anticoagulants, and cyclophosphamide was also used in 2 patients. Their renal function improved gradually and MPO-ANCA disappeared after immunosuppressive treatment.

Topics: Adult; Antibodies, Antineutrophil Cytoplasmic; Antirheumatic Agents; Arthritis, Rheumatoid; Disease Progression; Female; Glomerulonephritis; Humans; Male; Middle Aged; Penicillamine; Peroxidase

Topics: Anti-Inflammatory Agents, Non-Steroidal; Arthritis, Rheumatoid; Cyclooxygenase 2; Humans; Isoenzymes; Membrane Proteins; Peroxidase; Prostaglandin-Endoperoxide Synthases

We have demonstrated previously that patients with rheumatoid arthritis (RA) show an increase in serum and synovial fluid levels of complexes between alpha1-proteinase inhibitor (alpha1PI) and IgA. These are believed to form through disulfide binding between the Cys232 residue on alpha1PI and the penultimate cysteine residue (Cys471) of the IgA alpha chain. The mechanism for this has not been elucidated. We show here that alpha1PI oxidized by the myeloperoxidase-hydrogen peroxide (MPO-H2O2) system promotes the formation of IgA-alpha1PI complexes when incubated with IgA and that such complexes have no inhibitory activity against porcine pancreatic elastase (PPE). The activity of alpha1PI was considerably reduced also in IgA-alpha1PI complexes isolated from serum of an RA patient. We suggest that formation of IgA-alpha1PI complexes in inflammation may involve oxidation of alpha1PI, and as a consequence the alpha1PI in such complexes has reduced elastase inhibitory activity.

Topics: alpha 1-Antitrypsin; Animals; Arthritis, Rheumatoid; Humans; Hydrogen Peroxide; Immunoglobulin A; Inflammation; Oxidation-Reduction; Pancreas; Pancreatic Elastase; Peroxidase; Protein Binding; Serine Proteinase Inhibitors; Swine

This investigation was designed to determine and compare the distribution pattern of anti-neutrophil cytoplasmic antibodies (ANCA) in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) in the presence or absence of periodontal disease.. Sera of 30 patients with SLE and 30 with RA were tested for ANCA utilizing an indirect enzyme immunosorbent assay (ELISA) directed to a neutrophil granular extract and 6 neutrophil granule proteins. A control group of 20 healthy individuals showing neither evidence of periodontal disease nor systemic compromise was also included in this study.. For RA, the number of ANCA-positive sera was very low but was evenly distributed among patients with and without periodontitis. Conversely, a high number of ANCA-positive sera in SLE was found mostly in individuals presenting periodontal compromise. A statistically significant association between ANCA and periodontitis in SLE patients was found (P <0.005, chi square test).. A marked difference in the number and distribution of ANCA with respect to periodontitis between RA and SLE was found. Hyperresponsiveness of B cells and polyclonal B activation to periodontopathic bacteria in SLE might be accountable for the high numbers of ANCA and the close association observed between those autoantibodies and periodontitis in SLE.

Topics: Adult; Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Autoantigens; B-Lymphocytes; Bacteria; Cathepsin G; Cathepsins; Chi-Square Distribution; Enzyme-Linked Immunosorbent Assay; Female; Humans; Lactoferrin; Leukocyte Elastase; Lupus Erythematosus, Systemic; Lymphocyte Activation; Male; Middle Aged; Muramidase; Myeloblastin; Neutrophils; Periodontitis; Peroxidase; Serine Endopeptidases

Rheumatoid arthritis is a systemic disease of unknown etiology. The purpose of this study was to elucidate an unrecognized interaction between neutrophilic myeloperoxidase (MPO) and macrophages (Mphi) which could perpetuate the inflammatory response associated with arthritis. A monoarticular arthritis was induced by intra-articular injection of group A streptococcus cell wall fragments (PG-APS) into the ankle joint of female Lewis rats. After swelling/erythema subsided, joints were reinjected with either recombinant MPO or enzymatically inactive MPO (iMPO). Joint measurements were made daily and arthritis was confirmed by histology. Neither iMPO nor MPO could initiate "clinical" arthritis; however, either form of the enzyme injected after PG-APS induced a dose-dependent increase in erythema and swelling. Mannans, which block the binding of MPO to Mo, ablated clinical symptoms. Also, the presence of tumor necrosis factor alpha was observed only in diseased joints using immunocytochemistry.

Topics: Animals; Arthritis, Rheumatoid; Disease Models, Animal; Female; Macrophages; Neutrophils; Peroxidase; Rats; Rats, Inbred Lew; Streptococcus pyogenes; Tumor Necrosis Factor-alpha

To evaluate a role of myeloperoxidase (MPO) and antibody to myeloperoxidase (anti-MPO) in vasculitis, MPO and anti-MPO were determined by enzyme-linked immunosorbent assays in sera from 43 patients with vasculitis, 40 with rheumatoid arthritis, 36 with systemic lupus erythematosus (SLE), 23 with mixed connective tissue disease, 13 with systemic sclerosis, 22 with polymyositis/dermatomyositis, 18 with Sjögren's syndrome, and 30 normal controls. Kidney and lung sections from patients with vasculitis were stained for MPO. Anti-MPO titers were significantly higher (p<0.005) in the patients with vasculitis (mean+/- SD absorbance at 405 nm: 0.53 +/- 0.37) than in any other groups (0.15 +/- 0.04 to approximately 0.21 +/- 0.11). MPO levels in patients with vasculitis were comparable with those in patients with other diseases except SLE. In two patients with vasculitis, anti-MPO decreased sharply with simultaneous increases in MPO 1-2 weeks after they developed pulmonary hemorrhage. Numerous cells positive for MPO infiltrated the Bowman's spaces. These results indicate that MPO may contribute to the pathogenesis of vasculitis and a sudden fall in anti-MPO may predict a poor prognosis in some cases.

Topics: Animals; Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Blood Proteins; Defensins; Dermatomyositis; Humans; Kidney Glomerulus; Lupus Erythematosus, Systemic; Mice; Mice, Inbred BALB C; Microcirculation; Mixed Connective Tissue Disease; Peroxidase; Proteins; Scleroderma, Systemic; Vasculitis

The aim of this work was to determine differences in pro- and anti-inflammatory cytokine and adhesion molecule expression in synovial tissue from patients with rheumatoid arthritis (RA) or osteoarthritis (OA). Synovial tissue samples were obtained from patients with RA and OA, and from healthy individuals. The expression of mRNA of interleukin (IL)-1beta, IL-4, IL-6, IL-8, IL-10, IL-13, tumour necrosis factor-alpha (TNF-alpha) and transforming growth-factor-beta1 (TGF-beta1) was evaluated by the polymerase chain reaction (PCR). In addition, IL-8 and IL-10 transcripts were measured by quantitative PCR. The expression of IL-8 and IL-10 proteins was determined by immunoperoxidase staining. To evaluate the inflammatory stage of synovial tissue, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) protein expression was also determined. RA patients were found to display higher levels of adhesion molecules than patients with OA. PCR analysis showed a similar profile of cytokine transcripts between the OA and RA groups. Gene expression of IL-4 and IL-13 in synovium was undetectable. In contrast, IL-1beta, IL-6, IL-8, IL-10, TNF-alpha and TGF-beta1 transcripts were expressed by both groups. Increased levels of IL-8 and IL-10 transcripts and their proteins were observed in synovium from RA patients when compared to patients with OA and healthy controls. Thus, our data show that IL-8, IL-10, ICAM-1 and VCAM-1 expression levels are higher in synovial tissue from patients with RA than in similar tissue from patients with OA.

Topics: Adult; Arthritis, Rheumatoid; Cytokines; Gene Expression; Humans; Immunoenzyme Techniques; Intercellular Adhesion Molecule-1; Interleukin-10; Interleukin-8; Middle Aged; Osteoarthritis; Peroxidase; Polymerase Chain Reaction; Synovial Membrane; Vascular Cell Adhesion Molecule-1

We report a myeloperoxidase antineutrophil cytoplasmic antibody-positive rheumatoid arthritis patient who developed necrotizing crescentic glomerulonephritis. Steroid therapy was given combined with an immunosuppressant agent, and double-filtration plasmapheresis was started with the aim of removing antibodies from the blood. This therapeutic regimen was found to be useful.

Topics: Adult; Anti-Inflammatory Agents; Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Cyclophosphamide; Female; Glomerulonephritis; Humans; Immunosuppressive Agents; Methylprednisolone; Peroxidase; Plasmapheresis

Haemosiderin-laden alveolar macrophages are a common finding in patients with alveolar bleeding. Iron-positive macrophages, suggestive of subclinical alveolar bleeding, were found to be fairly common in bronchoalveolar lavage (BAL) fluid in primary systemic vasculitis but uncommon in collagen vascular diseases (CVDs) and rheumatoid arthritis (RA). To substantiate the impression that subclinical alveolar bleeding may be a feature distinguishing between these disorders, fibreoptic bronchoscopy and BAL were performed in 49 patients with active Wegener's granulomatosis or Churg-Strauss syndrome and 44 patients with CVDs or RA, all of them without clinically manifest alveolar bleeding. The percentage of iron-positive cells was compared with clinical and radiological findings. Only a minority of the CVD and RA patients had iron-positive alveolar macrophages; the 95th percentile of the median number of such cells was 5%. Fifty-three per cent of the patients in the vasculitis group had >5% iron-positive cells, with individual counts ranging up to 95%. Patients with iron-positive macrophages had more extensive disease, more frequent microhaematuria, a higher antineutrophil cytoplasmic antibody titre, a higher myeloperoxidase concentration in the BAL fluid and somewhat more frequent low-attenuation opacities in pulmonary high-resolution computed tomography than the patients with a low iron-positive cell count. In conclusion, subclinical alveolar bleeding was, indeed, a common finding in antineutrophil cytoplasmic antibody-associated vasculitis, which distinguished these disorders from lung disease due to collagen vascular diseases or rheumatoid arthritis. Its association with indices of disease activity, although weak in this cross-sectional study, merits a longitudinal study of its value for the long-term monitoring of vasculitis patients.

Topics: Aged; Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Bronchoalveolar Lavage Fluid; Bronchoscopy; Cell Count; Churg-Strauss Syndrome; Collagen; Female; Granulomatosis with Polyangiitis; Hemorrhage; Humans; Iron; Lung Diseases; Macrophages, Alveolar; Male; Middle Aged; Peroxidase; Pulmonary Alveoli; Retrospective Studies; Severity of Illness Index; Tomography, X-Ray Computed

Estimate the contribution of monocytes/macrophages to the disease process in rheumatoid arthritis (RA), by measuring the serum levels of the leucocyte-derived granular proteins: lysozyme, myeloperoxidase (MPO), lactoferrin and human neutrophil lipocalin (HNL).. Serum levels of these granular proteins were measured in patients with RA (n=23) and in healthy controls (n=27), and in 10 patients with RA after treatment with low-dose prednisolone. The serum levels of the granular proteins were also measured before and after treatment with metyrapone, a substance that inhibits the synthesis of cortisol in the adrenals.. The serum levels of lysozyme and MPO were elevated in patients with RA, while the concentrations of lactoferrin and HNL were similar in both groups. Prednisolone treatment decreased the serum concentration of lysozyme and MPO. Metyrapone did not influence the level of the granular proteins measured.. The increased serum levels of lysozyme and MPO, but not of HNL and lactoferrin in RA could indicate a stimulated secretory activity of mononuclear phagocytes. The measurement of serum lysozyme, as an indicator of monocyte/macrophage activity, might be used to study disease activity in RA.

Topics: Acute-Phase Proteins; Adult; Aged; Aged, 80 and over; Anti-Inflammatory Agents; Arthritis, Rheumatoid; Biomarkers; Carrier Proteins; Female; Humans; Lactoferrin; Lipocalin-2; Lipocalins; Macrophages; Male; Metyrapone; Middle Aged; Monocytes; Muramidase; Oncogene Proteins; Peroxidase; Prednisolone; Proto-Oncogene Proteins

We present here a case of MPO-ANCA positive rapidly progressive glomerulonephritis (RPGN) after 34 months of D-penicillamine (D-PC) therapy for rheumatoid arthritis (RA). A 27-year-old Japanese woman was diagnosed as having RA in June 1994 at our out-patient clinic. Oral D-PC administration was initiated at a dose of 100 mg per day in January 1995. In August 1997, proteinuria, hematuria, renal insufficiency, and anemia developed. D-PC was withdrawn promptly, and prednisolone 5 mg per day was started. The patient was admitted to our hospital in September. On admission, anti-neutrophil cytoplasmic antibody against mycloperoxidase (MPO-ANCA) was strongly positive in the serum. Renal biopsy showed glomerulonephritis with cellular crescent formation in 60% of the glomeruli observed. Immunofluorescence examinations revealed deposits of granular IgG, IgA, C 1 q, and C 3 in the mesangium. The patient was treated with steroid pulse therapy along with administration of anti-coagulation and anti-platelet agents under the diagnosis of MPO-ANCA positive D-PC-induced RPGN. The renal function was gradually recovered and MPO-ANCA disappeared. Since RPGN is potentially a fatal disease, frequent monitoring of renal function and discontinuation of D-PC are required. In case MPO-ANCA becomes positive, prompt and correct diagnosis of the renal disorder could lead to a good prognosis as in this case. The present case may provide some important immunological insights into medical procedures to treat D-PC-induced RPGN and MPO-ANCA related glomerulonephritis.

Topics: Adult; Antibodies, Antineutrophil Cytoplasmic; Antirheumatic Agents; Arthritis, Rheumatoid; Chronic Disease; Female; Glomerulonephritis; Humans; Penicillamine; Peroxidase

It was investigated to what extent isolated, monomeric and polymeric carbohydrates as well as cartilage specimens are affected by hydroxyl radicals generated by gamma-irradiation or Fenton reaction and what products can be detected by means of NMR spectroscopy. Resonances of all protons in glucose and other monosaccharides as well as carbon resonances in 13C-enriched glucose were continuously diminished upon gamma-irradiation. Formate and malondialdehyde were found as NMR detectable products in irradiated glucose solutions under physiologically relevant (aerated) conditions. In polysaccharide solutions (e.g. hyaluronic acid) gamma-irradiation and also treatment with the Fenton reagent caused first an enhancement of resonances according to mobile N-acetyl groups at 2.02 ppm. This indicates a breakdown of glycosidic bonds in polysaccharides. Using higher radiation doses or higher concentrations of the Fenton reagent formate was also detected. The same sequence of events was observed upon treatment of bovine nasal cartilage with the Fenton reagent. First, glycosidic linkages in cartilage polysaccharides were cleaved and subsequently formate was formed. In contrast, collagen of cartilage was affected only to a very low extent. Thus, HO-radicals caused the same action on cartilage as on isolated polymer solutions, inducing a fragmentation of polysaccharides and the formation of formate.

Topics: Animals; Arthritis, Rheumatoid; Carbohydrate Metabolism; Carbohydrates; Cartilage; Cattle; Formates; Gamma Rays; Glucose; Hydrogen Peroxide; Hydroxyl Radical; Hypochlorous Acid; Iron; Luminescent Measurements; Magnetic Resonance Spectroscopy; Malondialdehyde; Monosaccharides; Peroxidase; Polysaccharides; Reactive Oxygen Species; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Synovial Fluid; Uronic Acids

Rheumatoid arthritis (RA) is characterized by an abnormal cellular and cytokine infiltration of inflamed joints. This study addresses a previously unrecognized interaction between neutrophilic-myeloperoxidase (MPO) and macrophages (Mphi) which could explain the perpetuation of inflammation associated with RA. A monoarticular arthritis was induced in female Lewis rats by injection of streptococcal cell wall extracts (PG-APS). After swelling and erythema subsided, joints were re-injected with one of the following: porcine MPO or partially inactivated MPO (iMPO). Injection with either MPO or iMPO induced a 'flare' of experimental RA. Blocking the Mphi-mannose receptor by mannans, ablated exacerbation of disease. These results indicate that MPO or iMPO can play a pivotal role in the perpetuation but not initiation of this RA model.

Topics: Animals; Arthritis, Rheumatoid; Disease Models, Animal; Female; Macrophage Activation; Macrophages; Neutrophils; Peroxidase; Rats; Rats, Inbred Lew

Two patients with rheumatoid arthritis (RA) developed necrotizing crescentic glomerulonephritis with high titers of anti-myeloperoxidase antibodies (MPO) in the absence of overt extrarenal vasculitis. We therefore suggest that in some patients with RA, MPO-ANCA necrotizing glomerulonephritis (GN) may occur as a kidney-limited form of rheumatoid vasculitis, and that RA should be added to the list of diseases potentially associated with necrotizing GN with anti-MPO antibodies. These observations also point out the importance of repeatedly evaluating titers of anti-MPO antibodies in the course of RA, especially if renal impairment or abnormal urinary sediment are present.

Topics: Aged; Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Autoantibodies; Biopsy; Female; Glomerulonephritis; Humans; Kidney Glomerulus; Male; Peroxidase

A 56-year-old man was admitted to our hospital due to gradually developing consciousness disturbance. He had an 11-year history of sero-negative rheumatoid arthritis (Stage III) maintained by daily administration of 10 mg of prednisolone and 300 mg of actarit. On admission, he showed meningeal irritation and a marked increase in eosinophils in his cerebrospinal fulid (CSF) (457/microliter), while eosinophils in his peripheral blood were not increased (0/microliter). Shortly after admission he fell into a coma. Upon measurement in the coma state, his peripheral blood eosinophil count was found to be increased (max: 1742/microliter). Parasitic infection, Angiostrongylus cantonensis in particular, was excluded both by repeated microscopic examination of CSF and by immunological approaches for CSF and serum. Serum examinations showed broad cross-reaction between various parasitic antigens and positive myeloperoxdase-antineutrophil cytoplasmic antibody (18 EU/ml). Three pulses of methylprednisolone (500 mg/day) followed by conventional prednisolone therapy (60 mg/day) was effective for alleviating the signs and symptoms of eosinophilic meningoencephalitis. In this patient, it was considered that the cerebrospinal angiitis resulting in eosinophilic meningoencephalitis had been elicited by immunological abnormalities.

Topics: Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Autoimmunity; Biomarkers; Eosinophilia; Humans; Male; Meningoencephalitis; Methylprednisolone; Middle Aged; Peroxidase; Prednisolone; Pulse Therapy, Drug; Treatment Outcome; Vasculitis, Central Nervous System

Topics: Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Humans; Peroxidase

We determined the occurrence of antineutrophil cytoplasmic antibodies (ANCAs) and their specificities in 77 rheumatoid arthritis (RA) patients and compared them with 25 patients with psoriatic arthritis (Pso), 19 with drug-induced lupus erythematosus (DI-LE) and 11 with systemic lupus erythematosus (SLE). Thirty-two percent of RA patients had positive indirect immunofluorescence (IIF) stains (P or atypical ANCA). Twenty-nine per cent of patients with rheumatoid vasculitis (RAV), 48% with long-standing RA (LSRA) and 20% with early RA (Ely RA) had positive ANCAs compared with 4% of Pso patients, 47% of DI-LE patients and 45% of SLE patients. Western blotting (with polymorphonuclear cell extracts or alpha-granules) and alpha-granule enzyme-linked immunosorbent assay (ELISA) yielded variable results and proved unhelpful for characterizing the specificities of ANCAs. ELISAs based on commercial purified lactoferrin (LF), myeloperoxidase (MPO), human elastase (HLE) and cathepsin G (CG) showed that anti-HLE antibody was the most prevalent (14%) antibody in RA, followed by anti-MPO antibody and anti-LF antibody (10% each). Statistical analysis of antibody prevalence by clinical presentation showed that LSRA patients were more likely to have anti-HLE antibody and that DI-LE patients were more likely to have anti-CG antibody compared with the other patient groups. In lupus patients serial ELISA titration of ANCAs (LF and MPO) was found to be reliable for predicting the outcome. The overall incidence of ANCAs in RA patients was 33% by IIF.

Topics: Antibodies, Anti-Idiotypic; Antibodies, Antineutrophil Cytoplasmic; Antibody Specificity; Arthritis, Psoriatic; Arthritis, Rheumatoid; Autoantibodies; Biomarkers; Humans; Immunoglobulin G; Lactoferrin; Lupus Erythematosus, Systemic; Pancreatic Elastase; Peroxidase; Time Factors

Recently, it has been reported that hypochlorous acid (HOCl), a special product of neutrophil myeloperoxidase, degrades N-acetyl groups of N-acetylglucosamine, chondroitin sulfate, hyaluronic acid, and minced articular cartilage via a transient product to acetate. This work concerns 1H NMR investigations of synovial fluids of patients with rheumatoid arthritis (RA). Synovial fluids of patients with severe forms of this disease are characterized by enhanced 1H NMR signals for N-acetyl groups (approximately 2.0 ppm) and acetate (1.90 ppm) and the appearance of a broad but less intense signal at 2.35 ppm. It is likely that this signal corresponds to the transient, chlorinated product of degradation of N-acetyl groups by hypochlorous acid. Moreover, 1H NMR signal intensities of N-acetyl groups and acetate strongly correlate with the myeloperoxidase activities in synovial fluids from patients with rheumatoid arthritis. These results have been confirmed by treatment of native sheep synovial fluid with sodium hypochlorite, resulting in the formation of the same resonances as observed in pathologically changed synovial fluids from humans. Thus, it is concluded that HOCl plays an important role for the cartilage degradation during rheumatoid arthritis.

Topics: Acetylgalactosamine; Acetylglucosamine; Animals; Arthritis, Rheumatoid; Humans; Hypochlorous Acid; Magnetic Resonance Spectroscopy; Peroxidase; Sheep; Synovial Fluid

Antineutrophil cytoplasmic antibodies (ANCA) are present in several vasculitides and in other immunomediated diseases. The reported prevalence of ANCA in rheumatoid arthritis (RA) is variable. In addition, the presence of such autoantibodies has been poorly investigated in synovial fluid (SF). The objectives of this study were (1) to investigate the presence of ANCA both in the serum and in SF from patients with RA and other forms of synovitis (OS); (2) to analyze the reactivity of ANCA against isolated antigens proteinase 3 (PR3), myeloperoxidase (MPO) and lactoferrin (LF); and (3) to evaluate the clinical relevance of these autoantibodies.. Twenty-eight patients with RA, 13 with OS, and 17 with osteoarthritis (OA) of the knee joint were studied. No patient had clinical manifestations of vasculitis. SF and serum samples were investigated for the presence of ANCA by indirect immunofluorescence (IIF); the reactivity against PR3, MPO and LF was assessed by ELISA.. ANCA were detected by IIF in SF of 39.3% patients with RA, 38.5% with OS, and 5.9% with OA. With 2 exceptions, patients who had ANCA in SF showed positivity also in serum. The presence of both anti-MPO and anti-LF antibodies was found in 3 patients with RA and 1 with OA; a patient with RA showed antibodies only against LF and another one with RA only against MPO. No reactivity was found against PR3. In patients with RA ANCA were not associated with disease activity.. We found an increased incidence of ANCA both in SF and serum from patients with RA and OS. The pathogenic role and the clinical relevance of such autoantibodies in these diseases remain to be established.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Antinuclear; Arthritis, Rheumatoid; Demography; Disease Progression; Dose-Response Relationship, Immunologic; Enzyme-Linked Immunosorbent Assay; Female; Fluorescent Antibody Technique, Indirect; Humans; Joint Diseases; Lactoferrin; Male; Middle Aged; Peroxidase; Synovial Fluid; Synovitis

The reports on the patients with rheumatoid arthritis (RA) complicated with the myeloperoxidase specific-antineutrophil cytoplasmic antibody (MPO-ANCA) associated glomerulonephritis, whose clinical feature is rapidly progressive glomerulonephritis (RPGN), have been rare. We here report three cases of RPGN with MPO-ANCA in RA patients. Case 1. A 44-year-old woman with RA for 25 years was admitted because of RPGN. The level of MPO-ANCA was markedly high (293 EU) and the histological examination of the kidney showed diffuse crescentic glomerulonephritis. In spite of the intensive immunosuppressive therapy, her renal function did not recover and she underwent hemodialysis (HD). Case 2. A 58-year-old man with RA for 5 years was admitted due to RPGN (MPO-ANCA ; 147 EU, Ccr ; 16 ml/min) with the nephrotic syndrome and fever. The treatment with the immunosuppressive agents and the plasma exchange was partially effective to stop the rapid progression of the disease, but a few months later, his renal function worsened (Ccr 7 ml/min). A recent histological examination of the kidney failed to establish the CrGN because of endstage kidney. Case 3. A 56-year-old woman with RA for the past 10 years was admitted because of RPGN (MPO-ANCA ; 652EU). Intensive therapy could not be performed because of an active duodenal ulcer and markedly impaired renal function (Ccr ; 6 ml/min), and soon she underwent HD. Renal biopsy was not done. These three cases suggest that RPGN can occur in part of RA patients with MPO-ANCA.

Topics: Adult; Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Disease Progression; Female; Glomerulonephritis; Humans; Male; Middle Aged; Peroxidase

It is suggested that some drugs may be converted by inflammatory cells to yield active species. The transformation may be non-enzymatic, although being driven by the enzymatic production of highly reactive species which are normal products of activated leukocytes, such as singlet oxygen, hydrogen peroxide, hypochlorite, hydroxyl radical and nitric oxide. Drugs which may be transformed in this fashion are the anti-rheumatic gold complexes which may be converted either to aurocyanide or to Au(III) complexes by myeloperoxidase in polymorphonuclear leukocytes. Salicylate may also be activated by its oxidation to dihydroxybenzoates although evidence for its transformation is weaker than for the gold complexes.

Topics: Animals; Anti-Inflammatory Agents; Arthritis, Rheumatoid; Biotransformation; Cyanates; Cyanides; Gold; Gold Compounds; Humans; Hydroxylation; Monocytes; Neutrophils; Oxidation-Reduction; Peroxidase; Salicylates

Autoimmune diseases, such as rheumatoid arthritis and inflammatory bowel disease are characterized by chronic inflammatory responses resulting in tissue damage. These diseases have a number of common denominators including: abnormal cytokine expression, aberrant antigen-antibody complexes, T cell anomalies, and increased numbers of neutrophils and macrophages. We propose that the interaction between neutrophils and macrophages induces a state of chronic inflammation which contributes to the disease state. One of the central players in this scenario is myeloperoxidase (MyPo). This enzyme functions in the 'cytotoxic triad' and is involved in cell killing. Studies done by the present investigators have known that MyPo, which is released from neutrophils, induces macrophages to secrete interleukin-1, interferon alpha beta and tumor necrosis factor alpha. Furthermore, our studies have suggested a major immunoregulatory role of this enzyme. We propose that the release of MyPo from neutrophils and subsequent binding to macrophages initiates a cascade of events which enhance the production of reactive oxygen intermediates and cytokine expression resulting in the chronic inflammatory state associated with autoimmune diseases.

Topics: Animals; Arthritis, Rheumatoid; Autoimmune Diseases; Chronic Disease; Cytokines; Humans; Inflammation; Inflammatory Bowel Diseases; Macrophages; Neutrophil Activation; Neutrophils; Peroxidase; Reactive Oxygen Species

We describe 2 cases of a lupus syndrome induced by sulfasalazine in rheumatoid arthritis. All symptoms resolved and antihistone antibodies disappeared when sulfasalazine was discontinued. In one patient, perinuclear antineutrophil cytoplasmic antibodies with specificity for myeloperoxidase were found critically increased just before the occurrence of vasculitis.

Topics: Aged; Antibodies, Antineutrophil Cytoplasmic; Antibodies, Antinuclear; Antibody Specificity; Arthritis, Rheumatoid; Autoantibodies; Female; Humans; Lupus Erythematosus, Systemic; Middle Aged; Peroxidase; Sulfasalazine; Syndrome

To determine the prevalence and clinical associations of autoantibodies to myeloperoxidase (MPO) in an unselected series of well-characterised outpatients with rheumatoid arthritis (RA) and to compare the distribution of IgG subclasses of anti-MPO antibodies in these patients with that in patients with systemic vasculitis.. A study was made of 97 patients with RA, who have been seen regularly in this department for up to 20 years, and 29 patients with anti-neutrophil cytoplasmic antibody (ANCA) positive systemic vasculitis. Anti-MPO antibodies were detected using a direct-binding enzyme-linked immunosorbent assay (ELISA) with MPO from human granulocytes as antigen. The IgG subclass of anti-MPO antibodies was determined by ELISA using isotype specific monoclonal antibodies.. Anti-MPO antibodies were detected in 12% of patients with RA. Six sera contained IgG anti-MPO antibodies only, 1 IgM only and 5 antibodies of both classes. In the patients with RA the predominant subclasses were IgG1 and IgG3: only 2 sera contained detectable IgG4 antibodies. This was in contrast to patients with vasculitis, in whom most sera contained IgG1, IgG3 and IgG4 anti-MPO antibodies. Anti-MPO antibodies in sera from both patient groups bound only to the native protein. None of the patients studied with RA had evidence of vasculitis affecting the nerves or kidney: three patients (1 positive for anti-MPO antibodies and 2 negative) had cutaneous vasculitis. In the patients with RA, positivity for anti-MPO antibodies was associated with nodules and number of active joints. Three patients with anti-MPO antibodies, and none without, had pulmonary fibrosis.. Twelve per cent of a group of unselected outpatients with RA, but without evidence of major systemic vasculitis, had anti-MPO antibodies in their serum. Positivity for anti-MPO antibodies was more common in patients with nodular disease and lung involvement but not in patients with cutaneous vasculitis. IgG4 sub-class anti-MPO antibodies were present in 90% of sera from patients with ANCA-positive vasculitis and only 2/11 (18%) of anti-MPO antibody containing sera from patients with RA.

Topics: Adult; Aged; Aged, 80 and over; Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Autoantibodies; Blotting, Western; Female; Humans; Immunoglobulin G; Immunoglobulin M; Male; Middle Aged; Peroxidase; Vasculitis

In this study we examined the sera from 42 randomly selected patients with RA. ANCA was demonstrated by indirect immunofluorescence on human granulocytes in 10 patients with active disease and in none of the patients with inactive disease. ELISA's for the detection of specific antigens showed the presence of anti-myeloperoxidase in 3 patients, and anti-lactoferrin in 1 patient. The specificity of the remaining antibodies was unidentified. All 3 patients with antibodies to myeloperoxidase had vasculitis.

Topics: Antibodies, Antineutrophil Cytoplasmic; Arthritis, Rheumatoid; Autoantibodies; Autoantigens; Fluorescent Antibody Technique; Humans; Lactoferrin; Peroxidase; Vasculitis

Complete functional deficiency of the phagocytic cell enzyme, myeloperoxidase, is described in a patient with rheumatoid arthritis. Measurement of oxygenation and free radical activity by blood monocytes and polymorphonuclear leucocytes shows gross reduction in myeloperoxidase-dependent chemiluminescence. Implications of these data for theories linking reactive oxygen species to inflammatory tissue damage in rheumatoid arthritis are discussed.

Topics: Adult; Antibodies, Monoclonal; Arthritis, Rheumatoid; Enzyme Activation; Female; Free Radicals; Humans; Luminescent Measurements; Monocytes; Neutrophils; Oxidation-Reduction; Peroxidase; Phagocytes; Superoxides

Previous work has shown that synovial fluid isolated from patients with active rheumatoid arthritis contains soluble (not sedimented by centrifugation at 11,600 g for two minutes) and insoluble (sedimented by centrifugation at 11,600 g for two minutes) immunoglobulin aggregates that are capable of activating reactive oxidant production by bloodstream neutrophils. The purpose of this study was to determine which of these types of immunoglobulin aggregates activated the secretion of reactive oxygen metabolites and granule enzymes from neutrophils.. Cell free synovial fluid (from patients with rheumatoid arthritis) was added to neutrophils isolated from blood of healthy controls that had been incubated in the presence and absence of granulocyte-macrophage colony stimulating factor (GM-CSF). Reactive oxidant production was measured by luminol chemiluminescence (which detects both intracellular and extracellular oxidant production) and by cytochrome c reduction (which measures superoxide secretion).. The soluble aggregates only activated neutrophils that were previously primed, and activated a rapid and transient burst of reactive oxidant secretion. On the other hand, the insoluble aggregates activated primed and unprimed neutrophils with similar efficacy and most of the oxidants generated (especially in unprimed cells) were intracellular. The soluble aggregates, but not the insoluble aggregates, also activated the secretion of myeloperoxidase from neutrophils that had either been pretreated with cytochalasin B or primed with GM-CSF.. It is thus proposed that these soluble immunoglobulin aggregates are responsible for activation of the release of tissue damaging granule enzymes and reactive oxidants from primed neutrophils within the rheumatoid joint.

Topics: Adult; Aged; Aged, 80 and over; Arthritis, Rheumatoid; Cells, Cultured; Dose-Response Relationship, Immunologic; Humans; Immunoglobulins; Luminescent Measurements; Middle Aged; Neutrophils; Oxygen; Peroxidase; Protein Denaturation; Solubility; Synovial Fluid

Insoluble immunoglobulin aggregates present in the synovial fluid of patients with rheumatoid arthritis have been examined for their ability to activate reactive oxidant and granule enzyme secretion from bloodstream neutrophils. These insoluble complexes activated luminol chemiluminescence, but did not activate O2-, H2O2 or granule enzyme secretion and did not activate lucigenin chemiluminescence, which also measures reactive oxidant secretion. Hence, the luminol chemiluminescence detected after activation by insoluble immunoglobulin aggregates must be due to intracellularly generated reactive oxidants, i.e. produced within phagolysosomes. Because reactive oxidant and granule enzyme secretion has occurred within rheumatoid joints, other mechanisms of neutrophil activation must exist.

Topics: Arthritis, Rheumatoid; Humans; Immunoglobulins; Luminescent Measurements; Luminol; Neutrophils; Oxidants; Peroxidase; Synovial Fluid

An inhibitor of myeloperoxidase has been identified in the synovial fluids and sera from patients with rheumatoid arthritis and sera from normal subjects. Initially, these fluids were found to inhibit stimulus induced degranulation of polymorphonuclear leucocytes independently of the stimulating agent. Subsequently, the fluids were shown to inhibit the released enzyme rather than the degranulation response of polymorphonuclear leucocytes. Both rheumatoid and normal serum samples contained high concentrations of the inhibitor but the concentrations were lower in rheumatoid synovial fluids. The inhibitory activity seemed to be specific for peroxidase as the fluids did not inhibit beta-glucuronidase activity. A protein of relative molecular mass (Mr) 150 kd was purified from synovial fluid by affinity chromatography on myeloperoxidase-Sepharose. It is concluded that serum and synovial fluid contain a novel myeloperoxidase inhibitor, which acts by binding to myeloperoxidase and thereby prevents myeloperoxidase releasing oxidative products in serum.

Topics: Adult; Aged; Arthritis, Rheumatoid; Chromatography, Affinity; Female; Humans; Male; Middle Aged; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Peroxidase; Synovial Fluid

Topics: Antibodies; Arthritis, Rheumatoid; Female; Fluorescent Antibody Technique; Humans; Male; Neutrophils; Peroxidase; Prospective Studies

Anti-neutrophil cytoplasm antibodies (ANCA) occur occasionally in rheumatoid arthritis (RA), but their incidence and clinical significance have been unclear. In this study we have investigated 58 patients with RA. In 22 patients the disease was inactive and the remaining 36 with active disease were further subdivided into those without clinical evidence of vasculitis (26), those with cutaneous vasculitis (8) and those with systemic vasculitis (2). ANCA were demonstrated by indirect immunofluorescence in 10 of the 58 patients (17%). While both perinuclear (pANCA) and cytoplasmic (cANCA) staining were detected, pANCA were more common (70%). Neutrophil-specific anti-nuclear antibodies (ANNA) were demonstrated in a further eight sera (14%) and ANA were detected on Hep-2 cells in 30 of the 58 sera (52%). ELISAs for the detection of anti-myeloperoxidase and anti-elastase antibodies were then established. Five sera with pANCA and five that contained ANNA were negative for both anti-myeloperoxidase and anti-elastase antibodies, suggesting other as yet unidentified cytoplasmic antigens as the target molecules. However, anti-myeloperoxidase or anti-elastase antibodies were found in four sera that had homogeneous or speckled ANA on both Hep-2 cells and neutrophils. One serum contained both antibodies. The presence of ANCA detected by indirect immunofluorescence or of anti-myeloperoxidase or anti-elastase antibodies in these patients with RA was not associated with disease activity nor with the demonstration of cutaneous vasculitis or renal disease (P NS). A possible association with systemic vasculitis remains to be confirmed. There is an incomplete correlation between indirect immunofluorescence patterns and antibody specificity in ELISA systems.

Topics: Antibodies, Antinuclear; Arthritis, Rheumatoid; Autoantigens; Blotting, Western; Cytoplasm; Fluorescent Antibody Technique; Humans; Kidney Diseases; Molecular Weight; Neutrophils; Pancreatic Elastase; Peroxidase; Vasculitis

The oxidative metabolism of neutrophils isolated from the bloodstream and synovial fluid of 16 patients with rheumatoid arthritis was compared by measuring the ability of neutrophils to generate luminol dependent chemiluminescence and to secrete O2-. Measurements of receptor mediated--that is, N-formyl-methionyl-leucyl-phenylalanine stimulated--activation or receptor and second message independent--that is phorbol myristate acetate stimulated--activation showed that synovial fluid neutrophils had biochemical characteristics to suggest that they had been either up-regulated (primed) or down-regulated (activated) in vivo. These conclusions were confirmed by comparison of these responses with the changes in oxidative metabolism observed during in vitro priming and activation of control neutrophils: synovial fluid neutrophils possessed lower levels of myeloperoxidase than paired bloodstream cells, and unlike bloodstream cells could not be primed in vitro. These data thus suggest that synovial fluid neutrophils have been exposed to both priming and activating agents within rheumatoid joints.

Topics: Adult; Aged; Aged, 80 and over; Arthritis, Rheumatoid; Cytochalasin B; Humans; Luminescent Measurements; Middle Aged; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; Oxygen; Peroxidase; Stimulation, Chemical; Synovial Fluid; Tetradecanoylphorbol Acetate

An inhibitor of myeloperoxidase (MPO) has been identified in normal human serum. Initial experiments confirmed that high levels of MPO inhibitory activity are present in sera and that the inhibitor did not act by interfering with the assay. Purification of the inhibitor activity by salt precipitation followed by ion exchange and affinity chromatography revealed the presence of a protein of 150 kD. The purified inhibitory activity displayed dose and time dependency and was not associated with IgG or IgA. It is considered that human serum contains an inhibitor of extracellular MPO capable of protecting against hypohalous acid release in host tissues and that if inhibitor levels are reduced such protection may fail.

Topics: Arthritis, Rheumatoid; Chromatography, Affinity; Chromatography, Ion Exchange; Dose-Response Relationship, Drug; Enzyme-Linked Immunosorbent Assay; Humans; Peroxidase; Serum Albumin; Synovial Fluid

Synovial fluid isolated from 16 patients with rheumatoid arthritis activated luminol dependent chemiluminescence in bloodstream neutrophils, and the maximal activity stimulated varied over a 50-fold range. In contrast, these same fluids only activated a much lower range (two- to threefold) of maximal rates of lucigenin dependent chemiluminescence and cytochrome c reduction, two assays which only measure oxidant secretion which is independent of myeloperoxidase. Over 95% of the luminol dependent chemiluminescence activated by all samples was inhibited by azide (indicating its dependence upon myeloperoxidase), but anti-(myeloperoxidase) IgG (which specifically inhibits only the extracellular activity of this enzyme) only inhibited the response stimulated by some samples: those fluids which activated the highest luminol dependent chemiluminescence also stimulated the greatest activity of an extracellular myeloperoxidase-H2O2 system. A clear correlation was shown to exist between the activity of myeloperoxidase already present in the fluids (after its secretion from neutrophils in situ within the rheumatoid joint) and the ability of the fluid to activate luminol dependent chemiluminescence. It is concluded, therefore, that all synovial fluid samples tested possess almost equivalent levels of a factor(s) which activated O2-/H2O2 secretion and that the variations in the measured activity of the extracellular myeloperoxidase-H2O2 system are dependent upon the level of degranulation which had occurred within the joint.

Topics: Acridines; Adult; Aged; Aged, 80 and over; Arthritis, Rheumatoid; Azides; Cytochrome c Group; Humans; Hydrogen Peroxide; Immunoglobulin G; Luminescent Measurements; Luminol; Middle Aged; Neutrophils; Peroxidase; Synovial Fluid

No difference was found between the degranulation responses to FMLP of synovial fluid (SF) polymorphonuclear leucocytes (PMNL), from patients with rheumatoid arthritis (RA), and either paired blood PMNL or blood PMNL from a healthy donor. In contrast, the response of SF PMNL to heat-aggregated IgG was often reduced compared with autologous blood PMNL. Similarly, SF from some (35%) RA patients stimulated degranulation of PMNL but the response of SF-derived PMNL to autologous stimulatory SF was reduced compared with the response of blood PMNL. The stimulatory activity of the SF was removed by sepharose-protein A. These results were taken to suggest that the activity is due to immunoglobulin aggregates and that SF PMNL (from some RA patients) are tachyphylactic to stimulation by immunoglobulin aggregates as measured by degranulation because they have been stimulated by immunoglobulin aggregates in vivo. In other studies the concentration of myeloperoxidase (MPO) was measured enzymically in RA SF and was found to be present in varying amounts. However, only a weak relationship was found between MPO levels and either PMNL numbers or levels of complement-bearing IgG aggregates in SF. It is considered that the relationship between MPO and immunoglobulin aggregates levels is obscured by the presence of a peroxidase inhibitor in the fluids and/or because only aggregates bound to tissue stimulate degranulation in vivo.

Topics: Adult; Aged; Arthritis, Rheumatoid; Cell Degranulation; Female; Humans; Immunoglobulin G; Male; Middle Aged; Neutrophils; Peroxidase; Synovial Fluid

Sixteen patients with classical rheumatoid arthritis (RA) complicated by severe vasculitis were studied and compared with a matched control group of 17 RA patients without vasculitis. A control group of 24 patients with unrelated disease was also included. Neither antineutrophil cytoplasmic antibodies (C-ANCA) nor anti-myeloperoxidase (anti-MPO) were found. Granulocyte specific antinuclear antibodies ("GS-ANA") were found in a higher frequency in the vasculitis group (75%) than in the RA control group (41%), but the difference was not statistically significant. No patient in the control group without RA had "GS-ANA".

Topics: Aged; Aged, 80 and over; Antibodies; Antibody Specificity; Arthritis, Rheumatoid; Cytoplasm; Enzyme-Linked Immunosorbent Assay; Female; Granulocytes; Humans; Male; Neutrophils; Peroxidase; Vasculitis

Alkaline phosphatase (AP), acid phosphatase and myeloperoxidase (MP) activity and the level of cation protein (CP) in blood and synovial fluid (SF) neutrophils were studied and compared in 54 patients with rheumatoid arthritis (RA) and in 22 patients suffering from primary osteoarthrosis deformans (OAD) combined with reactive synovitis. As compared to the patients with OAD, the patients with RA manifested a significant rise of AP, acid phosphatase and MP activity together with a decrease of the level of CP in blood neutrophils. Meanwhile in SF neutrophils from the patients with RA, all the parameters appeared higher than in OAD and were lower that in blood neutrophils in both the groups. As compared to the routine biochemical and cytological tests, the diagnostic information content of the cytochemical parameters of blood neutrophils (AP, acid phosphatase) and SF neutrophils (AP, acid phosphatase, MP) from the patients with RA (against the patients suffering from OAD) was noticeably higher.

Topics: Acid Phosphatase; Adult; Aged; Alkaline Phosphatase; Arthritis, Rheumatoid; Blood Proteins; Clinical Enzyme Tests; Diagnosis, Differential; Female; Histocytochemistry; Humans; Male; Middle Aged; Neutrophils; Osteoarthritis; Peroxidase; Synovial Fluid

Synovial fluid (SF) polymorphonuclear leucocytes (PMN) from patients with rheumatoid arthritis (RA) were compared to RA and normal circulating blood PMN. RA SF PMN were as viable as blood PMN and remained viable for up to 24 h in culture. Measurement of myeloperoxidase indicated that RA SF PMN had degranulated and secreted their myeloperoxidase prior to isolation, 26.5 +/- 11.7% being found extracellularly compared to less than 2.9% in RA and normal blood PMN. RA SF PMN alone showed a decrease in basal NADPH-oxidase activity as well as an increase in responsiveness to stimulation by chemotactic peptide during culture. Stimulation of PMN with phorbol-12-myrisitate-13-acetate evoked equivalent responses in each population before and after culture. These results demonstrate a major difference in resting and receptor-mediated activation of superoxide release by RA SF PMN. Together, these results have important implications in identifying the role of the activated PMN in RA.

Topics: Arthritis, Rheumatoid; Blood Cell Count; Cell Count; Cell Separation; Cell Survival; Cells, Cultured; Female; Firefly Luciferin; Humans; Luminescent Measurements; Male; Middle Aged; N-Formylmethionine Leucyl-Phenylalanine; NADH, NADPH Oxidoreductases; NADPH Oxidases; Neutrophils; Peroxidase; Superoxides; Synovial Fluid

We have used rocket immunoelectrophoresis and immunoblotting to detect myeloperoxidase in synovial fluid from patients with rheumatoid arthritis. This protein was enzymatically inactive but its identity as myeloperoxidase was confirmed by comparing its subunit structure with that of the purified enzyme. When neutrophils were stimulated to secrete myeloperoxidase in vitro, a polypeptide with an apparent molecular mass of 62 kDa was detected extracellularly by immunoblotting. Neutrophils isolated from synovial fluid showed a reduced level of this 62 kDa polypeptide but it was detected extracellularly in synovial fluid by immunoblotting. Thus, we conclude that neutrophils in synovial fluid from patients with rheumatoid arthritis have been activated in vivo to secrete myeloperoxidase and propose that the products of this enzyme system can contribute to the tissue damage associated with this disease.

Topics: Arthritis, Rheumatoid; Humans; Immunoelectrophoresis; Neutrophils; Peptides; Peroxidase; Proteins; Synovial Fluid

Although the etiology of rheumatoid interstitial lung disease (RILD) remains unknown, bronchoalveolar lavage (BAL) has been useful in studying potentially pathogenic mechanisms in this disorder. Previous investigations in patients with rheumatoid arthritis (RA) and RILD revealed abnormal BAL T-lymphocyte subpopulations and a significant elevation in BAL neutrophils. Because neutrophils have been implicated as important effector cells in inflammatory disorders such as ARDS and idiopathic pulmonary fibrosis, we evaluated BAL fluid in patients with RA for neutrophil chemotactic and activating properties and for evidence of neutrophil activation. The BAL fluid from patients with RILD contained significant neutrophil chemotactic activity derived from both lipid and nonlipid components. Evidence for neutrophil stimulation in the lower respiratory tract of patients with RILD was suggested by elevations in both myeloperoxidase activity and immunologically determined levels of human neutrophil elastase in BAL fluid. Free uninhibited elastolytic activity, however, was not demonstrated, suggesting that adequate protease inhibitor levels were present to inhibit active elastase activity. In addition to elevated myeloperoxidase activity, a potential role for neutrophil-derived oxidant injury was indirectly suggested by the enhanced release of superoxide anion (O2-) from resting normal human blood neutrophils challenged with concentrated BAL fluid from patients with RA and interstitial lung disease. Significant correlations were found between physiologic parameters and the percentage of BAL neutrophils, as well as levels of neutrophil-derived mediators. For example, levels of human neutrophil elastase were strongly correlated with diminished diffusion capacity (r = -0.73, p less than 0.001) and reduced forced vital capacity (r = -0.63, p less than 0.006).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Arthritis, Rheumatoid; Bronchoalveolar Lavage Fluid; Chemotaxis, Leukocyte; Chronic Disease; Humans; Leukocyte Count; Neutrophils; Pancreatic Elastase; Peroxidase; Prospective Studies; Pulmonary Fibrosis; Respiratory System; Superoxides

Topics: Acid Phosphatase; Adult; Alkaline Phosphatase; Arthritis, Rheumatoid; Catalase; Female; Glucuronidase; Humans; Microscopy, Electron; Middle Aged; Neutrophils; Peroxidase

Ascorbic acid, at physiological concentrations, can scavenge the myeloperoxidase-derived oxidant hypochlorous acid at rates sufficient to protect alpha 1-antiprotease against inactivation by this molecule. The rapid depletion of ascorbic acid at sites of inflammation, as in the inflamed rheumatoid joint, may therefore facilitate proteolytic damage.

Topics: alpha 1-Antitrypsin; Antioxidants; Arthritis, Rheumatoid; Ascorbic Acid; Chromatography, High Pressure Liquid; Hydrogen-Ion Concentration; Hydroxides; Hydroxyl Radical; Hypochlorous Acid; Oxidation-Reduction; Pancreatic Elastase; Peroxidase

Activated phagocytic cells produce superoxide (O2-) and hydrogen peroxide (H2O2); their production is important in bacterial killing by neutrophils and has been implicated in tissue damage by activated phagocytes. H2O2 and O2- are poorly reactive in aqueous solution and their damaging actions may be related to formation of more reactive species from them. One such species is hydroxyl radical (OH.), formed from H2O2 in the presence of iron- or copper-ion catalysts. A major determinant of the cytotoxicity of O2- and H2O2 is thus the availability and location of metal-ion catalysts of OH. formation. Hydroxyl radical is an initiator of lipid peroxidation. Iron promoters of OH. production present in vivo include ferritin, and loosely bound iron complexes detectable by the 'bleomycin assay'. The chelating agent Desferal (desferrioxamine B methanesulphonate) prevents iron-dependent formation of OH. and protects against phagocyte-dependent tissue injury in several animal models of human disease. The use of Desferal for human treatment should be approached with caution, because preliminary results upon human rheumatoid patients have revealed side effects. It is proposed that OH. radical is a major damaging agent in the inflamed rheumatoid joint and that its formation is facilitated by the release of iron from transferrin, which can be achieved at the low pH present in the micro-environment created by adherent activated phagocytic cells. It is further proposed that one function of lactoferrin is to protect against iron-dependent radical reactions rather than to act as a catalyst of OH. production.

Topics: Arthritis, Rheumatoid; Bleomycin; Blood Bactericidal Activity; Deferoxamine; Ferritins; Free Radicals; Humans; Hydroxides; Iron Chelating Agents; Lactoferrin; Metals; Oxygen; Oxygen Consumption; Peroxidase; Peroxides; Phagocytes; Transferrin

The maturity of peripheral blood mononuclear phagocytes (B-MPs) from patients with rheumatoid arthritis (RA), osteoarthritis (OA), and reference ("normal") subjects was compared. Mononuclear cell isolates from peripheral blood were separated on discontinuous gradients of Percoll into low density (more mature) and high density (less mature) subpopulations. Contrary to expectations, the proportion of immature B-MPs in RA patients was found to be significantly lower than that in reference subjects. In RA patients with synovial effusions the proportion of immature B-MPs approached but did not exceed those found in reference subjects, despite the fact that 31% of these patients displayed a peripheral blood monocytosis. It was concluded that the bone marrow precursor population had adapted to the long-term demand for B-MPs in the course of this chronic inflammatory disease.

Topics: Adult; Aged; Arthritis, Rheumatoid; Cell Differentiation; Cell Separation; Humans; Leukocyte Count; Middle Aged; Monocytes; Osteoarthritis; Peroxidase; Reference Values; Synovial Fluid

We investigated the effect of antiarthritic drugs containing thiol groups, such as D-penicillamine, tiopronin (N-[2-mercaptopropionyl]glycine), sodium aurothiomalate, and aurothioglucose, on the chlorinating activity of myeloperoxidase purified from human leukocytes. Hypochlorite, the reactive product of the reaction catalyzed by myeloperoxidase, was effectively scavenged by these antiarthritic drugs, and in addition, D-penicillamine and tiopronin inhibited myeloperoxidase itself. The above-mentioned effects of these drugs were observed at concentrations that occur in the serum of rheumatoid arthritis patients treated with these agents. We suggest that the therapeutic effect of these antiarthritic drugs may be due to the protection of tissues against the reactive HOCI released by activated granulocytes at inflamed sites.

Topics: Amino Acids, Sulfur; Arthritis, Rheumatoid; Aurothioglucose; Cyclohexanones; Gold Sodium Thiomalate; Humans; Hydrogen Peroxide; Hypochlorous Acid; Leukocytes; Penicillamine; Peroxidase; Tiopronin

Activated platelets release substances which potentially can contribute to joint lesions in inflammatory arthritides. To elucidate a possible participation of platelets in inflammatory joint reactions, the concentrations of the platelet protein beta-thromboglobulin (beta-TG) were measured in 90 inflammatory synovial fluids. Seven percent of the patients with rheumatoid arthritis and none of the patients with other inflammatory joint diseases (e.g., Reiter's disease, reactive or crystal arthritides) had beta-TG concentrations in synovial fluid exceeding the upper normal range of plasma beta-TG. The absent or very modest signs of local platelet activation were contrasted by the pronounced neutrophilic and monocytic activation, as assessed by the measurements of some granule proteins: lactoferrin, myeloperoxidase, lysozyme, and ferritin. No correlation was found between these inflammatory cell markers and beta-TG. A positive correlation (p less than 0.001) was noted between beta-TG and beta 2-microglobulin, which appeared in particularly high amounts in rheumatoid arthritis. This correlation may reflect a disturbed permeability of synovial membrane for LMW proteins or a related activation of platelets and lymphocytes. The present results do not give any evidence of platelet activation playing a major role in proliferative or destructive processes in arthritis.

Topics: Adolescent; Adult; Aged; Arthritis, Reactive; Arthritis, Rheumatoid; beta 2-Microglobulin; Beta-Globulins; beta-Thromboglobulin; Blood Platelets; Female; Humans; Lactoferrin; Male; Middle Aged; Peroxidase; Synovial Fluid

We investigated the effect of D-penicillamine on the ability of myeloperoxidase, purified from human leukocytes, to catalyse the oxidation of chloride ions to hypochlorite (HOCl) in the presence of H2O2. It is shown that, due to the interaction of D-penicillamine with both myeloperoxidase itself and HOCl, the chlorinating activity of myeloperoxidase in the presence of H2O2 and chloride ions is prevented. A concentration of 100 microM D-penicillamine inhibits the chlorinating activity of myeloperoxidase completely, which Is due to the stabilization of Compound II, an inactive form of the enzyme. In addition, HOCl reacts directly with D-penicillamine. Analysis of the reaction products of D-penicillamine and HOCl showed that D-penicillamine was oxidized to penicillamine disulphide and penicillamine sulphinic acid, and eventually deaminated (indicated by the release of ammonia). Lower concentrations of D-penicillamine (10 microM) inhibited myeloperoxidase less, but still acted as effective scavengers of HOCl. In very low concentrations (1 microM), D-penicillamine did not scavenge HOCl effectively, but rather stimulated the chlorinating activity of myeloperoxidase. However, when instead of D-penicillamine a comparable amount of ascorbate was added, a similar but even larger stimulation was observed. Since the concentration of free D-penicillamine in serum from rheumatoid patients treated with this drug is about 20 microM (Saetre, R. and Rabenstein, D.L. (1978) Anal. Chem. 50, 276-280), the therapeutic effect of D-penicillamine may be due to the protection of tissues against the reactive HOCl released by activated granulocytes at inflammation sites.

Topics: Amino Acids; Arthritis, Rheumatoid; Chlorides; Humans; Hydrogen Peroxide; Hydrogen-Ion Concentration; Penicillamine; Peroxidase; Peroxidases

Topics: alpha 1-Antitrypsin; Amino Acid Sequence; Animals; Arthritis, Rheumatoid; Chemical Phenomena; Chemistry; Humans; Oxidation-Reduction; Pancreatic Elastase; Peroxidase; Swine; Synovial Fluid

In 31 patients, covering a wide range of blood neutrophil counts and turnover rates, the plasma concentrations of myeloperoxidase and lactoferrin have been measured with radioimmunoassays and compared to neutrophil kinetic parameters, measured with DF32P-labeled neutrophils. It was found that the plasma concentrations of both proteins correlated significantly with the total number of neutrophils in the blood (TBGP=total blood granulocyte pool) as well as with the neutrophil turnover rate (GTR=granulocyte turnover rate), which is evidence that neutrophilic granulocytes are the main suppliers of myeloperoxidase and lactoferrin to the plasma. In contrast to the previously demonstrated better relationship between the GTR and plasma lysozyme, a protein also originating in neutrophil granules, both myeloperoxidase and lactoferrin correlated better with the TBGP. These differences may reflect differences in the mode of release of intragranular proteins from neutrophils to the plasma. The correlation of the plasma lactoferrin concentration with the TBGP was so good as to suggest its use in the clinical assessment of the TBGP.

Topics: Arthritis, Rheumatoid; Granulocytes; Hematologic Diseases; Hodgkin Disease; Humans; Lactoferrin; Lactoglobulins; Leukemia; Leukocyte Count; Liver Cirrhosis; Lymphoma, Non-Hodgkin; Neutrophils; Peroxidase; Peroxidases