cathepsin-g and Vasculitis

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

In patients with anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis, indirect immunofluorescence (IF) distinguishes between cytoplasmic (C-ANCA) and perinuclear (P-ANCA) neutrophil staining patterns. In patients with primary systemic vasculitis such as Wegener's granulomatosis, microscopic polyangiitis and Churg-Strauss syndrome, these IF staining patterns correspond broadly with antibodies to the two major antigens: the C-ANCA pattern is associated generally with antibodies to serine protease 3 (PR3) and the P-ANCA pattern with antibodies to myeloperoxidase (MPO). However, some sera positive for ANCA by IF are negative for anti-PR3 and anti-MPO antibodies, suggesting the presence of antibodies to minor antigens of PMN granules. We tested sera from a previously well-defined clinical cohort of patients for antibodies to four possible minor antigens: bactericidal permeability increasing protein, elastase, cathepsin G and lactoferrin. IF-positive (+) sera had significantly higher antibody frequencies to the minor antigens than did the IF-negative (-) sera (P < 0.01). Patients with IF(+) PR3(-)MPO(-) sera showed the most varied reactivity to the minor antigens. Among the IF(+) groups, the IF(+) PR3(+)/MPO(-) sera showed the lowest reactivity to the minor antigens. Patients with well-defined ANCA specificities, e.g. the PR3-ANCA response associated with Wegener's granulomatosis, are less likely than are other patient subsets to have antibodies to minor antigen targets. Autoantibodies to these minor antigens contribute to the overall pattern of ANCA identified by IF and help to explain why the correlation between IF and enzyme immunoassays show discrepancies. While the pathophysiological significance of antibodies to minor target antigens needs further evaluation, they may be markers of inflammation associated with disease processes.

Topics: Antibodies, Antineutrophil Cytoplasmic; Antimicrobial Cationic Peptides; Autoantibodies; Autoantigens; Blood Proteins; Cathepsin G; Cathepsins; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique, Indirect; Granulomatosis with Polyangiitis; Humans; Membrane Proteins; Neoplasm Proteins; Peroxidase; Serine Endopeptidases; Vasculitis

The detection rate of antineutrophil cytoplasmic antibodies (ANCA) in Chinese patients with clinically suspected small vessel vasculitis was investigated, and their antigen specificity and demographic features were analyzed. A number of sera (n = 5,604) sent to our referral laboratory for ANCA screening were tested by indirect immunofluorescence (IIF), enzyme-linked immunosorbent assays (ELISAs) for myeloperoxidase (MPO)- and proteinase 3 (PR3)-ANCA. Then the IIF-ANCA-positive sera that were negative for MPO- and PR3-ANCA were further tested by antigen-specific ELISA by using other five highly purified known ANCA antigens as solid-phase ligands. The known antigens included bactericidal/permeability-increasing protein (BPI), human leukocyte elastase (HLE), lactoferrin, cathepsin G, and azurocidins. Of the 5,604 sera, 267 (4.76%) sera were IIF-ANCA positive and 390 (7%) were antinuclear antibody (ANA) positive in the IIF assay. Of the IIF-positive samples, 213 were anti-MPO positive, 32 were anti-PR3 positive, and five cases were positive for both. Of the 48 sera positive for IIF-ANCA but negative for MPO- and PR3-ANCA, 13 sera (27%) recognized other target antigens, 7 sera recognized BPI, 5 recognized HLE, 1 recognize cathepsin G, and 1 recognized azurocidin. None of the sera recognized lactoferrin, and one serum sample recognized both BPI and HLE. The majority of ANCA-positive patients presented in summer or winter. There was no difference in gender (male/female ratio, 1:1.12) in ANCA-positive patients with a mean age of 53.1 years. The male/female ratio was 1.17:1 for patients over 60 years of age; however, it was 1:4 for patients under 20 years of age. We conclude that ANCA-related diseases are not rare in China, and the major antigens are MPO and PR3. When the IIF technique is used to detect ANCA, ANA should be carefully distinguished.

Topics: Adolescent; Adult; Aged; Anemia, Hemolytic; Antibodies, Antineutrophil Cytoplasmic; Antibodies, Antinuclear; Antibody Specificity; Antimicrobial Cationic Peptides; Autoantibodies; Blood Proteins; Cathepsin G; Cathepsins; Child; China; Colitis, Ulcerative; Enzyme-Linked Immunosorbent Assay; Female; Fluorescent Antibody Technique, Indirect; Granulomatosis with Polyangiitis; Humans; Lactoferrin; Leukocyte Elastase; Male; Membrane Proteins; Middle Aged; Myeloblastin; Peroxidase; Seasons; Serine Endopeptidases; Sex Factors; Vasculitis

To characterize the antigen specificity of circulating anti-neutrophil cytoplasmic antibodies (ANCAs) in inflammatory bowel disease (IBD).. Analysis of the prevalence of circulating ANCAs in patients with ulcerative colitis and Crohn's disease, by both non-specific methods (immunofluorescence against fixed neutrophil leukocytes) and specific antigen techniques (against purified neutrophil leukocyte constituents).. Indirect immunofluorescence against fixed polymorphonuclear leukocytes, and solid-phase enzyme-linked immunosorbent assay (ELISA) against neutrophil constituents (alpha-granules, elastase, myeloperoxidase, cathepsin g, lysozyme and lactoferrin).. Although results using immunofluorescence were typical of other studies (ulcerative colitis positive in 41%, Crohn's disease in 10%), ELISA studies showed antibody activity against neutrophil components in 69% of patients with ulcerative colitis and 39% of those with Crohn's disease. Antibodies in ulcerative colitis were commonly directed (in descending order) against lysozyme, cathepsin G, elastase, and lactoferrin, and in Crohn's disease against lysozyme.. Correlation of indirect immunofluorescence data and ELISA results indicated that even this large panel of specific antigens fails to identify all the ANCA targets in IBD. The lack of correlation between the findings of ANCAs, either in general or versus a specific target, and disease extent or activity in ulcerative colitis supports the suggestion that ANCAs are unlikely to be of primary importance in pathogenesis.

Topics: Adult; Aged; Antibodies; Antibodies, Antineutrophil Cytoplasmic; Autoantibodies; Cathepsin G; Cathepsins; Cholangitis, Sclerosing; Colitis, Ulcerative; Crohn Disease; Cytoplasmic Granules; Enzyme-Linked Immunosorbent Assay; Epitopes; Female; Fluorescent Antibody Technique, Indirect; Humans; Immunoglobulin G; Inflammatory Bowel Diseases; Lactoferrin; Leukocyte Elastase; Male; Middle Aged; Muramidase; Neutrophils; Pancreatic Elastase; Peroxidase; Serine Endopeptidases; Vasculitis

Topics: Antibodies, Antineutrophil Cytoplasmic; Autoantibodies; Blotting, Western; Cathepsin G; Cathepsins; Cytoplasmic Granules; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique; Humans; Immunoglobulin G; Lactoferrin; Muramidase; Myeloblastin; Neutrophils; Pancreatic Elastase; Peroxidase; Proteins; Serine Endopeptidases; Vasculitis