osteoprotegerin and Spondylitis--Ankylosing

We aimed to determine the association between serum receptor activator of nuclear factor-kappa B ligand (sRANKL) levels and ankylosing spondylitis (AS) in Chinese patients.. The PubMed, Cochrane Library, Embase, Chinese Biomedical Database, Web of Science, China National Knowledge Infrastructure, VIP, and Wan Fang databases were searched for studies conducted before October 1, 2020, without language restrictions. STATA version 12.0 and Revman version 5.3 were used to analyze the data. The standard mean differences (SMDs) and corresponding 95% confidence intervals (95% CIs) were calculated.. Twelve clinical case-control studies, including 585 patients with AS and 423 healthy controls, were included. The combined SMD for sRANKL suggested that the sRANKL level was significantly higher in Chinese patients with AS than in healthy controls (SMD: 3.27, 95% CI 2.11-4.43, P < 0.00001). Serum RANKL-related factor osteoprotegerin (OPG) levels (SMD: 0.86, 95% CI 0.09-1.64, P < 0.03) were lower in the Chinese patients with AS than in healthy controls, and the RANKL/OPG ratio (SMD = 1.05, 95% CI 0.64-1.46, P < 0.00001) in Chinese patients with AS was approximately the same as that of healthy controls. Subgroup analysis indicated that patients from North and South China had higher sRANKL levels than controls; the sRANKL levels of patients from South China were higher in the subgroup with a Bath Ankylosing Spondylitis Functional Index (BASFI) of > 4 than those of patients in other subgroups. In terms of duration, patients with AS for > 8 years had higher sRANKL levels than health controls. Other subgroup analyses were conducted by region, language, source of control, age, and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). In these subgroups, the sRANKL levels were significantly higher in the patients with AS than in healthy controls. The BASFI and BASDAI were sources of heterogeneity.. The sRANKL levels are higher in Chinese patients with AS, especially among those from South China. sRANKL levels may be positively correlated with the pathogenesis of AS among Chinese patients.

Topics: Asian People; Case-Control Studies; Humans; Language; Osteoprotegerin; RANK Ligand; Spondylitis, Ankylosing

With the growing awareness of the impact of chronic back pain and axial spondyloarthritis and recent breakthroughs in genetics and the development of novel treatments which may impact best on early disease, the need for markers that can facilitate early diagnosis and profiling those individuals at the highest risk for a bad outcome has never been greater. The genetic basis of ankylosing spondylitis has been considerably advanced, and HLA-B27 testing has a role in the diagnosis. Knowledge is still incomplete of the rest of the genetic contribution to disease susceptibility, and it is likely premature to use extensive genetic testing (other than HLA-B27) for diagnosis. Serum and plasma biomarkers have been examined extensively in assessing disease activity, treatment response, and as predictors or radiographic severity. For assessing disease activity, other than C-reactive protein and erythrocyte sedimentation rate, the most work has been in examining cytokines (particularly interleukin 17 and 23), matrix metalloproteinase (MMP) markers (particularly MMP3). For assessing those at the highest risk for radiographic progression, biomarkers of bony metabolism, cartilage and connective tissue degradation products, and adipokines have been most extensively assessed. The problem is that no individual biomarkers has been reproducibly shown to assess disease activity or predict outcome, and this area still remains an unmet need, of relevance to industry stakeholders, to regulatory bodies, to the healthcare system, to academic investigators, and finally to patients and providers.

Topics: Adipokines; Aggrecans; Biomarkers; Bone and Bones; Cartilage; Cartilage Oligomeric Matrix Protein; Chitinase-3-Like Protein 1; Connective Tissue; Cytokines; Disease Progression; Genetic Markers; HLA-B27 Antigen; Humans; Lectins; Leukocyte L1 Antigen Complex; Matrix Metalloproteinases; Osteoprotegerin; Spondylarthropathies; Spondylitis, Ankylosing; Treatment Outcome

To evaluate the efficacy and safety of an oral phosphodiesterase 4 inhibitor, apremilast, in treatment of ankylosing spondylitis (AS) by monitoring symptoms and signs in a pilot study including exploratory investigation of effects of PDE4 inhibition on blood biomarkers of bone biology.. In this double-blind, placebo-controlled, single-centre, Phase II study, patients with symptomatic AS with active disease on MRI were randomised to apremilast 30 mg BID or placebo over 12 weeks. Bath Indices were monitored serially. Patients were followed for 4 weeks after stopping medication. Bone biomarkers were assessed at baseline and day 85.. 38 subjects were randomised and 36 subjects completed the study. Although the primary end-point (change in BASDAI at week 12) was not met, apremilast was associated with numerically greater improvement from baseline for all clinical assessments compared with placebo with mean change in BASDAI (-1.59±1.48 vs -0.77±1.47), BASFI (-1.74±1.91 vs -0.28±1.61) and BASMI (-0.51±1.02 vs -0.21±0.67); however, differences did not achieve statistical significance. The clinical indices returned to baseline values by 4 weeks after cessation of apremilast. Six apremilast patients (35.3%) vs 3 placebo (15.8%) achieved ASAS20 responses (p=0.25). There were statistically significant decreases in serum RANKL and RANKL:osteoprotegrin ratio and plasma sclerostin but no significant changes in serum DKK-1, bone alkaline phosphatase, TRAP5b, MMP3, osteoprotegrin, or osteocalcin.. Although a small pilot study, these results suggest that apremilast may be effective and well tolerated in AS and modulates biomarkers of bone biology. These data support further research of apremilast in axial inflammation.

Topics: Adaptor Proteins, Signal Transducing; Administration, Oral; Adult; Aged; Anti-Inflammatory Agents, Non-Steroidal; Biomarkers; Bone and Bones; Bone Morphogenetic Proteins; Disability Evaluation; Double-Blind Method; Female; Genetic Markers; Health Status; Humans; Male; Middle Aged; Osteoprotegerin; Phosphodiesterase 4 Inhibitors; Pilot Projects; RANK Ligand; Severity of Illness Index; Spondylitis, Ankylosing; Thalidomide; Treatment Outcome

Tumor necrosis factor-alpha has a prominent role in the inflammatory process and bone resorption in patients with ankylosing spondylitis (AS). We evaluated the markers of clinical efficacy and bone biochemical changes in Korean patients with AS treated with etanercept therapy.. Serum samples from 26 patients receiving etanercept for refractory AS were obtained at baseline and 12 weeks after treatment. Clinical measures and serum levels of transforming growth factor-Beta (TGF-Beta), matrix metalloproteinase-3 (MMP-3), macrophage-colony stimulating factor (M-CSF), bone-specific alkaline phosphatase (BALP), osteocalcin, C-telopeptide (CTX), receptor activator of nuclear factor-kB ligand (RANKL), and osteoprotegerin (OPG) were measured at each timepoint.. Significant improvement of the Bath AS Disease Activity Index (BASDAI) and Functional Index (BASFI) was achieved after 12 weeks (p < 0.001). ASsessments in Ankylosing Spondylitis Working Group (ASAS) 20 criteria were achieved by 22 patients (84.6%) after 12 weeks' treatment. ASAS 50 and 70 were achieved by 10 (38.5%) and 7 patients (26.9%). Serum levels of BALP and osteocalcin were significantly increased after 12 weeks of treatment (p < 0.05). Serum levels of CTX were not changed after treatment. Serum levels of TGF-Beta, MMP-3, and M-CSF were significantly decreased after 12 weeks of treatment (p < 0.05). Serum levels of OPG and RANKL were not changed. Change of MMP-3 had a high correlation coefficient with changes of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) upon etanercept treatment (CRP, r = 0.446, p = 0.022; ESR, r = 0.449, p = 0.021).. In patients with AS, etanercept therapy may be effective for reducing disease activity and improving bone biochemical markers. MMP-3 may be a useful biomarker for monitoring etanercept therapy.

Topics: Adult; Alkaline Phosphatase; Antirheumatic Agents; Biomarkers; Collagen Type I; Dose-Response Relationship, Drug; Etanercept; Female; Humans; Immunoglobulin G; Korea; Macrophage Colony-Stimulating Factor; Male; Matrix Metalloproteinase 3; Middle Aged; Osteocalcin; Osteoprotegerin; Peptides; RANK Ligand; Receptors, Tumor Necrosis Factor; Severity of Illness Index; Spondylitis, Ankylosing; Transforming Growth Factor beta

Ankylosing spondylitis (AS) exhibits paradoxical bone features typically characterized by new bone formation and systemic bone loss. Although abnormal kynurenine (Kyn), a tryptophan metabolite, has been closely linked to the disease activity of AS, the distinct role of its pathological bone features remains unknown.. Kynurenine sera level was collected from healthy control (HC; n = 22) and AS (n = 87) patients and measured by ELISA. In the AS group, we analyzed and compared the Kyn level based on the modified stoke ankylosing spondylitis spinal score (mSASSS), MMP13, and OCN. Under osteoblast differentiation, the treatment with Kyn in AS-osteoprogenitors conducted cell proliferation, alkaline phosphatase activity, bone mineralization-related alizarin red s (ARS), von kossa (VON), hydroxyapatite (HA) staining, and mRNA expression markers (ALP, RUNX2, OCN, and OPG) for bone formation. TRAP and F-actin staining was used for osteoclast formation of mouse osteoclast precursors.. Kyn sera level was significantly elevated in the AS group compared to the HC. In addition, Kyn sera level was correlated with mSASSS (r = 0.03888, p = 0.067), MMP13 (r = 0.0327, p = 0.093), and OCN (r = 0.0436, p = 0.052). During osteoblast differentiation, treatment with Kyn exhibited no difference in cell proliferation and alkaline phosphate (ALP) activity for bone matrix maturation but promoted ARS, VON, and HA staining for bone mineralization. Interestingly, osteoprotegerin (OPG) and OCN expressions of AS-osteoprogenitors were augmented in the Kyn treatment during differentiation. In growth medium, Kyn treatment of AS-osteoprogenitors resulted in induction of OPG mRNA, protein expression, and Kyn-response genes (AhRR, CYP1b1, and TIPARP). Secreted OPG proteins were observed in the supernatant of AS-osteoprogenitors treated with Kyn. Notably, the supernatant of Kyn-treated AS-osteoprogenitors interrupted the RANKL-mediated osteoclastogenesis of mouse osteoclast precursor such as TRAP-positive osteoclast formation, NFATc1 expression, and osteoclast differentiation markers.. Our results revealed that elevated Kyn level increased the bone mineralization of osteoblast differentiation in AS and decreased RANKL-mediated osteoclast differentiation by inducing OPG expression. Out study have implication for potential coupling factors linking osteoclast and osteoblast where abnormal Kyn level could be involved in pathological bone features of AS.

Topics: Animals; Cell Differentiation; Gene Expression Regulation; Kynurenine; Matrix Metalloproteinase 13; Mice; Osteoblasts; Osteoclasts; Osteoprotegerin; RANK Ligand; RNA, Messenger; Spondylitis, Ankylosing

Clinical studies indicate that recombinant tumor necrosis factor receptor:Fc fusion protein (rhTNFR:Fc) quickly alleviates symptoms and physical signs of active Ankylosing Spondylitis (AS), improving the manifestation of spinal inflammation on radiological imaging. However, the regulatory mechanism of rhTNFR:Fc in the chemokine pathway is unclear. Thus we study the mechanism of phlogogenic activity of CXCL16/CXCR6 in AS and the related mechanism of rhTNFR: Fc treatment.. Thirty-two cases of active AS were treated with rhTNFR:Fc for 3 consecutive months. Clinical response was evaluated at baseline and after treatment. CXCL16/CXCR6 expression as well as Receptor Activator Of Nuclear Factor-Κb Ligand (RANKL)/Osteoprotegerin (OPG), essential molecules for osteoclast differentiation, were studied in AS before and after treatment. Further, the proliferation of lymphocytes and the RANKL level stimulated by recombinant human CXCL16 (rhCXCL16) were measured in vitro.. Thirty cases responded to rhTNFR:Fc treatment. The RANKL level, RANKL/OPG ratio, CXCLl6 level in serum, and CXCLl6 and CXCR6 mRNA levels in active AS were higher than those in controls and treated patients (P<0.001). rhCXCL16 treatment increased lymphocyte proliferation and RANKL level in active AS (P<0.001), but not in controls or treated patients (P>0.05). A positive linear correlation was noted between CXCL16 serum levels and RANKL/OPG ratio and between CXCL16 levels and C-reactive protein results (P<0.001).. Our findings suggest that rhTNFR:Fc suppresses inflammation and bone destruction of AS by reducing the RANKL/OPG ratio through inhibition of the CXCL16/CXCR6 pathway.

Topics: Adolescent; Adult; Chemokine CXCL16; Down-Regulation; Etanercept; Female; Humans; Injections, Subcutaneous; Male; Middle Aged; Osteoprotegerin; RANK Ligand; Receptors, CXCR6; Spondylitis, Ankylosing; Young Adult

The present study investigates the osteoclastogenic capacity of peripheral blood mononuclear cells (PBMCs) in male patients with ankylosing spondylitis (AS). We demonstrated that monocytes from these patients display a lower capacity to generate osteoclasts compared to cells from healthy controls, and osteoclastogenesis was negatively correlated with disease duration.. Ankylosing spondylitis (AS) is a disease characterized by new bone growth that leads to syndesmophyte formation but AS patients frequently present with low bone mineral density/fractures. Osteoclastogenesis in AS patients is poorly studied and controversial. The aim of this study is to determine if the osteoclastogenic capacity of PBMCs is different in AS patients compared to controls and the relationship between osteoclastogenesis and clinical/laboratory parameters.. PBMCs from 85 male AS patients and 59 controls were tested for CD16+ cells and induced to differentiate into osteoclasts over 3 weeks in vitro. Serum levels of RANKL, osteoprotegerin (OPG), C-terminal telopeptide of type I collagen (CTX), and amino-terminal pro-peptide of type I collagen (P1NP) were also evaluated.. PBMCs from AS patients had fewer CD16+ cells and produced fewer osteoclasts compared to controls. Apoptosis occurred less frequently in osteoclasts obtained from AS patients than in osteoclasts from the controls. A lower RANKL/OPG and CTX/P1NP were observed in AS patients compared to controls. AS patients taking NSAIDs presented no difference regarding the number of OCs produced and the percentage of CD16+ cells compared to controls. However, patients taking TNF inhibitors (TNFi) presented lower OC numbers than controls. A negative correlation was demonstrated between the number of osteoclasts generated from PBMCs of AS patients and disease duration.. Monocytes from male AS patients display a lower capacity to generate osteoclasts in vitro compared to cells from controls. Osteoclastogenesis was negatively correlated with disease duration. This finding supports the idea that osteoclasts play a role in the physiopathology of bone disease in AS patients.

Topics: Adult; Apoptosis; Bone Density; Case-Control Studies; Cell Differentiation; Cells, Cultured; Collagen Type I; Cytokines; Humans; Male; Middle Aged; Monocytes; Osteoclasts; Osteoprotegerin; Peptide Fragments; Peptides; Procollagen; RANK Ligand; Spondylitis, Ankylosing; Young Adult

Wnt signaling plays an important role in development and maintenance of many organs and tissues. The most-studied secreted Wnt inhibitors are sclerostin (SOST), Dickkopf-related protein 1 (DKK-1), and secreted frizzled related protein 1 (SFRP-1) which play important roles in bone turnover. The present study investigated the relationship between serum Wnt inhibitors and diseases with excessive ossification structures, such as ossification of posterior longitudinal ligament (OPLL), ankylosing spondylitis (AS), diffuse idiopathic skeletal hyperostosis (DISH), and ossification of yellow ligament (OYL).. Twenty-five patients with AS, DISH, OPLL, or OYL were recruited in this study. Fasting peripheral blood samples were collected from all patients and nine controls. Various biomarkers of bone turnover including osteocalcin (OSC), osteoprotegerin (OPG), SFRP-1, DKK-1, and SOST were investigated.. Our data showed that serum levels of OSC were higher, but Dkk-1 levels were lower in AS, DISH, OPLL, and OYL patients than those in the controls. Serum levels of SFRP-1 were significantly higher in DISH patients than those in the controls. Serum levels of SOST were significantly higher in DISH and OPLL patients than both levels in the controls. Serum levels of OPG were lower in AS patients than those in the controls. Serum levels of OSC were higher in the OPLL patients than those in the AS patients. Serum levels of DKK-1, SFRP-1, SOST, and OPG were not significantly different between the different disease groups.. In this exploratory study, both OSC and DKK-1 levels are correlated with the clinical conditions associated with excessive ossification, indicating that blood OSC and DKK-1 levels may serve as diagnostic biomarkers for AS, DISH, OPLL, and OYL. These findings may also help discover potential drug therapies for management of these diseases in the future.

Topics: Adaptor Proteins, Signal Transducing; Adult; Aged; Aged, 80 and over; Biomarkers; Bone Density; Bone Morphogenetic Proteins; Bone Remodeling; Female; Genetic Markers; Humans; Hyperostosis, Diffuse Idiopathic Skeletal; Intercellular Signaling Peptides and Proteins; Intracellular Signaling Peptides and Proteins; Male; Membrane Proteins; Middle Aged; Ossification of Posterior Longitudinal Ligament; Osteocalcin; Osteoprotegerin; Proteins; Spondylitis, Ankylosing; Wnt Proteins; Wnt Signaling Pathway

Patients with ankylosing spondylitis (AS) reportedly have a higher mortality and morbidity risk. Osteoprotegerin (OPG) was recently defined as an important cardiovascular (CV) marker in the general population. We aimed to assess the relationship of serum OPG levels with arterial stiffness, carotid intima media thickness (CIMT), and clinical and laboratory data in AS patients. We examined 60 AS patients without CV disease or risk factors and 50 healthy controls. Disease activity was evaluated using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and the Ankylosing Spondylitis Disease Activity Score (ASDAS), whereas functional capacity was evaluated using the Bath Ankylosing Spondylitis Functional Index (BASFI). Serum OPG levels were measured with the enzyme-linked immunosorbent assay. Carotid-femoral pulse wave velocity (PWV) was used as an indicator of arterial stiffness, whereas CIMT (examined via carotid ultrasonography) was used to evaluate preclinical atherosclerosis. The mean serum OPG level, PWV, and CIMT were significantly higher in AS patients than in controls (106.7 ± 50.9 vs. 58.1 ± 12.7 pg/mL; 7.4 ± 1.8 vs. 6.2 ± 1.2 m/s; 0.72 ± 0.13 vs. 0.57 ± 0.07 mm, respectively; P < 0.001 for all). In AS patients, the serum OPG levels were not significantly correlated with PWV and CIMT but were significantly correlated with erthrocyte sedimentation rate, BASFI, and ASDAS. AS patients without CV disease or risk exhibited high OPG levels and increased PWV and CIMT values. Although OPG levels were not significantly correlated with PWV or CIMT, future long-term follow-up studies will help define the predictive value of OPG in these patients.

Topics: Adult; Anti-Inflammatory Agents, Non-Steroidal; Antirheumatic Agents; Atherosclerosis; Biological Products; Carotid Intima-Media Thickness; Cross-Sectional Studies; Female; Humans; Male; Middle Aged; Osteoprotegerin; Pulse Wave Analysis; Severity of Illness Index; Spondylitis, Ankylosing; Ultrasonography; Vascular Stiffness

To evaluate the effect of anti-TNF treatments on bone mineral density (BMD), bone remodelling markers (BRM) and receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG) in patients with chronic inflammatory joint diseases.. A longitudinal prospective study was performed under clinical practice conditions on 31 patients diagnosed of rheumatoid arthritis, psoriatic arthropathy and ankylosing spondylitis who had received treatment with anti-TNF alpha drugs for one year. BMD, OPG and RANKL soluble form (sRANKL) were studied at the onset and end of the study. During the study (0, 3, 6, 9 and 12 month), disease activity (SDAI, BASDAI and CRP), functional capacity (HAQ, BASFI), BRM and vitamin D were studied.. BMD was not modified after one year of treatment. The patients who took corticosteroids had a mean bone mass loss of 3% in the lumbar spine (±1.6, P=.02). In regards to the BRM, did not experience significant changes over the course of the study. Disease activity, both SDAI (P=.002) and BASDAI (P=.002), decreased. OPG was maintained without changes during the year of treatment while both the sRANKL (0.28±0.22, P=.013) and sRANKL/OPG ratio significantly decreased (0.04±0.03, P=.031).. The patients being treated with anti-TNF did not present with a significant loss of DMO during the study (one year), at the same time experiencing an improvement in disease activity. This protection has been clearer in the responding patients.

Topics: Adalimumab; Adult; Aged; Anti-Inflammatory Agents; Arthritis, Psoriatic; Arthritis, Rheumatoid; Biomarkers; Bone Density; Bone Remodeling; Chronic Disease; Etanercept; Female; Humans; Infliximab; Longitudinal Studies; Male; Middle Aged; Osteoprotegerin; Prospective Studies; RANK Ligand; Spondylitis, Ankylosing; Treatment Outcome; Tumor Necrosis Factor-alpha

Insight into the most important inflammatory pathways in ankylosing spondylitis (AS) could be of importance in risk stratification and the development of treatment strategies. Therefore, we aimed to compare circulating levels of inflammatory biomarkers between AS patients and controls, and explore associations between these biomarkers and clinical measures of disease activity.. In a cross-sectional study, 143 AS patients were compared with 124 population controls. Blood samples were analysed by immunoassays for interleukin (IL)-6, IL-17a, IL-23, soluble tumour necrosis factor receptor 1 (sTNF-R1) and 2 (sTNF-R2), and osteoprotegerin (OPG). Disease activity was measured by the AS Disease Activity Score (ASDAS) and the Bath AS Disease Activity Index (BASDAI).. Analysis of covariance (ANCOVA) demonstrated elevated plasma levels of sTNF-R1 [geometrical mean 0.94 (95% CI 0.88-1.00) vs. 0.83 (95% CI 0.78-0.89) ng/mL, p < 0.01] and OPG (2.3, 95% CI 2.1-2.4 vs. 2.0, 95% CI 1.9-2.2 ng/mL, p = 0.02) and, although not significant, of IL-23 (122, 95% CI 108-139 vs. 106, 95% CI 93-120 pg/mL, p = 0.07) in AS patients vs.. More AS patients had a high level of sTNF-R2 than controls (22 vs. 1, p < 0.01). No differences between the groups were seen for IL-6 and IL-17a. In patients, no significant associations were seen between inflammatory markers and disease activity measures after adjusting for personal characteristics.. Significantly higher plasma levels of sTNF-R1, sTNF-R2, and OPG and numerically but non-significantly higher levels of IL-23 were found in AS patients compared to controls, indicating that these cytokines and cytokine receptors are important inflammatory pathways. Clinical measures of disease activity were not significantly correlated with circulating inflammatory markers.

Topics: Adult; Biomarkers; Case-Control Studies; Cross-Sectional Studies; Cytokines; Female; Humans; Interleukin-23; Male; Middle Aged; Osteoprotegerin; Receptors, Cytokine; Receptors, Tumor Necrosis Factor, Type I; Receptors, Tumor Necrosis Factor, Type II; Severity of Illness Index; Spondylitis, Ankylosing

Ankylosing spondylitis (AS) patients whose symptom onset occurs before 16 years of age are termed juvenile-onset ankylosing spondylitis (JAS). Investigations suggested that JAS had worse functional outcome, and abnormality of bone metabolism can appear in early stage of AS. The objectives of this study are to compare changes of serum inflammatory and bone metabolic markers and to explore the relationship between these biomarkers and disease activity in JAS with different HLA-B27 subtypes. Serum matrix metallopeptidase-3 (MMP-3), soluble receptor activator of nuclear factor-κB ligand (sRANKL), and osteoprotegerin (OPG) were detected by ELISA in 56, 62, and 68 JAS patients, respectively, and 32 healthy individuals were as controls. Serum MMP-3 and sRANKL were significantly higher and OPG in JAS was slightly higher than those in controls. There was no significant difference in the level of MMP-3, sRANKL, and OPG among JAS patients with B27 negativity, B*2704, B*2705, and B*2715, respectively. Serum levels of MMP-3 showed positive correlation with BASDAI and BASFI (Bath Ankylosing Spondylitis Disease Activity Index and Functional Index). Serum level of sRANKL showed positive correlation with MMP-3 and negative correlation with disease duration. The significantly higher sRANKL expression suggested the enhanced osteoclast function and imbalance of RANKL/OPG system in the inflammatory process of JAS patients carrying different B27 subtypes. It should be paid attention to the abnormality of bone metabolism during the treatment of JAS.

Topics: Adolescent; Adult; Age of Onset; Biomarkers; Child; Female; HLA-B27 Antigen; Humans; Male; Matrix Metalloproteinase 3; Osteoprotegerin; RANK Ligand; Severity of Illness Index; Spondylitis, Ankylosing; Young Adult

To identify biomarkers for bone metabolism in patients with ankylosing spondylitis (AS) and to determine the relationship between these biomarkers and disease activity, back mobility, osteoproliferation, and bone mineral density (BMD).. Serum levels of Wingless protein (Wnt-3a), Dickkopf-1 (DKK-1), sclerostin, soluble receptor activator of nuclear factor-κB ligand (sRANKL), and osteoprotegerin were assessed using ELISA. Ankylosing Spondylitis Disease Activity Score-C reactive protein, Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis patient global score, and C-reactive protein (CRP) were used as disease activity measures, and Bath Ankylosing Spondylitis Metrology Index (BASMI) as a measure of spinal mobility. Lateral spine radiographs were scored for chronic AS-related changes (mSASSS). BMD was measured with dual-energy x-ray absorptiometry.. Two hundred four patients with AS (NY criteria; 57% men), with a mean age of 50 ± 13 years and disease duration 15 ± 11 years, and 80 age and sex-matched controls were included. The patients with AS had significantly higher serum levels of Wnt-3a (p < 0.001) and lower levels of sclerostin (p = 0.014) and sRANKL (p = 0.047) compared with the controls. High CRP was associated with low sclerostin (r(S) = -0.21, p = 0.003) and DKK-1 (r(S) = -0.14, p = 0.045). In multiple linear regression analyses, increasing BASMI and mSASSS were independently associated with older age, male sex, high CRP, and elevated serum levels of Wnt-3a. In addition, mSASSS remained associated with a high number of smoking pack-years after adjusting for age. Low BMD of femoral neck was associated with high mSASSS after adjusting for age.. Serum levels of Wnt-3a are elevated in AS and associated with increased BASMI and mSASSS, independent of age, indicating that Wnt-3a could be a biomarker for the osteoproliferative process.

Topics: Adaptor Proteins, Signal Transducing; Adolescent; Adult; Aged; Biomarkers; Bone and Bones; Bone Density; Bone Morphogenetic Proteins; Female; Genetic Markers; Humans; Male; Middle Aged; Osteoporosis; Osteoprotegerin; RANK Ligand; Severity of Illness Index; Spondylitis, Ankylosing; Wnt3A Protein; Young Adult

(1) To compare the serum levels of Dickkopf-1 (DKK-1) and bone biomarkers in patients with ankylosing spondylitis (AS) and healthy controls. (2) To examine the effects of anti-tumor necrosis factor-α (TNF-α) therapy for 3 months on bone biomarkers in patients with AS. We measured the levels of DKK-1, osteocalcin, osteoprotegerin, and C-terminal telopeptide of type I collagen (CTX-1) in patients with AS and in healthy controls at baseline and 3 months after initiating anti-TNF-α therapy in AS patients. Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores were also measured before and after anti-TNF-α therapy in AS patients. Serum levels of DKK-1 were significantly lower in the AS patients than in the controls (P < 0.0001). Osteocalcin and osteoprotegerin levels were significantly higher in the AS patients than in the controls (P < 0.0001). Serum levels of DKK-1 were not changed after the 3-month anti-TNF-α therapy. Osteocalcin level increased (P < 0.0001), osteoprotegerin level and BASDAI scores decreased (P = 0.025 and P < 0.0001, respectively) significantly after the 3-months anti-TNF-α therapy. Serum DKK-1 level was lower in patients with AS than in healthy controls and did not change after 3 months of anti-TNF-α therapy in the AS patients despite the marked improvement in BASDAI scores. These findings suggest the low serum DKK-1 level is related to the pathogenesis of new bone formation in AS, which is resistant to TNF-α blocking therapy.

Topics: Adalimumab; Adult; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Biomarkers; Case-Control Studies; Collagen Type I; Down-Regulation; Etanercept; Female; Humans; Immunoglobulin G; Immunologic Factors; Infliximab; Intercellular Signaling Peptides and Proteins; Male; Middle Aged; Osteocalcin; Osteogenesis; Osteoprotegerin; Peptides; Receptors, Tumor Necrosis Factor; Republic of Korea; Severity of Illness Index; Spondylitis, Ankylosing; Time Factors; Treatment Outcome; Tumor Necrosis Factor-alpha

To study the mechanism of Bushen Qiangdu Recipe (BQR) for regulating osteoprotegerin receptor activator for nuclear factor kappa B ligand (OPG/RANKL) pathway in ankylosing spondylitis (AS).. Thirty active AS inpatients or outpatients were recruited from Department of CM Rheumatology, China-Japan Friendship Hospital from January to May 2009. All patients were treated with BQR for 3 successive months, one dose daily, once in the morning and once in the evening. Besides, 30 healthy volunteers were recruited. The serum of patients and volunteers were collected. The osteoblast cell lines hFOB1. 19 were divided into 3 groups: the pre-treatment group, the post-treatment group, and the healthy volunteer group (as the control group). All cell lines were cultured by corresponding culture medium containing each serum. The supernatant from osteoblast cell lines was collected. The protein content of OPG/RANKL was detected using ELISA, and the protein expression of OPG/RANKL was detected using RT-PCR.. Compared with the control group, the OPG content, the mRNA and protein expressions of OPG, and the mRNA and protein expressions of OPG/RANKL all decreased, while the mRNA expression of RANKL increased in the pre-treatment group, showing statistical difference (P<0.05, P<0.01). Compared with the pre-treatment group, the OPG content, the mRNA and protein expressions of OPG significantly increased, and the mRNA and protein expressions of OPG/RANKL increased, while the mRNA expression of RANKL decreased in the post-treatment group, showing statistical difference (P<0.05, P<0.01).. AS patients' serum could directly inhibit the expression of OPG in osteoblasts, promote the expression of RANKL, and down-regulate the OPG/RANKL ratio. BQR containing serum might promote the osteogenesis and inhibit the bone resorption possibly through directly up-regulating the OPG/RANKL ratio in osteoblast, thus inhibiting the differentiation and function of osteoclast.

Topics: Adult; Case-Control Studies; Cell Line; Drugs, Chinese Herbal; Female; Humans; Male; Osteoblasts; Osteogenesis; Osteoprotegerin; RANK Ligand; Serum; Spondylitis, Ankylosing; Young Adult

Ankylosing spondylitis (AS) is a chronic inflammatory disease of spine and sacroiliac joints; it is characterized by new bone formation, and the disease processes can be accompanied by osteoporosis. In the present study, we investigated changes in bone mineral density (BMD) and in the levels of various bone turnover-related biomarkers and cytokines in a cohort of AS patients, with regard to clinical parameters, disease activity, and treatment regimen.. 55 AS patients and 33 healthy controls included in the study. Spinal mobility was assessed by the Bath Ankylosing Spondylitis Metrology Index (BASMI), and radiologic changes were scored by the Bath Ankylosing Spondylitis Radiologic Index (BASRI). Patients were also evaluated with the Bath Ankylosing Spondylitis Functional Index (BASFI) and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Bone mineral density (BMD) assessed by dual energy X-ray absorptiometry. Various biomarkers and cytokines of bone turnover including osteoprotegerin (OPG), serum band 5 tartrate-resistant acid phosphatase (TRAP-5), soluble receptor activator of nuclear factor kappa-B ligand (sRANKL), secreted frizzled-related protein 1 (sFRP-1), Dickkopf-related protein 1 (DKK-1), and sclerostin were studied.. The levels of TRAP-5, NTX, sRANKL, sclerostin, sFRP-1, DKK-1, and IFNγ, were similar between the patients and controls (p > 0.05), while BMD of femoral neck, and OPG levels were significantly lower in AS patients (p < 0.05). In a subgroup analysis, patients with active disease had significantly higher concentrations of OPG compared with the inactive group. Rest of the biomarkers and cytokines of bone turnover were similar between the active and inactive disease groups. Subgroup analysis of patients receiving anti-TNFα agents and conventional therapy revealed that OPG concentrations were significantly lower in the patients receiving biological drugs, while BAP and DKK-1 were significantly higher in the patients treated with conventional agents.. In this cross-sectional study we showed that OPG levels were significantly lower in AS patients compared to healthy subjects. On the other hand, the levels of wingless (Wnt) signal pathway inhibitors seem not altered. Ectopic bone formation in AS may be related to dysfunction of these molecules at the cellular level.

Topics: Absorptiometry, Photon; Acid Phosphatase; Adaptor Proteins, Signal Transducing; Adult; Ataxia Telangiectasia Mutated Proteins; Biomarkers; Biomechanical Phenomena; Bone Density; Bone Morphogenetic Proteins; Bone Remodeling; Case-Control Studies; Cell Cycle Proteins; Cross-Sectional Studies; Cytokines; Female; Femur Neck; Genetic Markers; Humans; Immunosuppressive Agents; Intercellular Signaling Peptides and Proteins; Isoenzymes; Male; Middle Aged; Osteoprotegerin; Protein Serine-Threonine Kinases; RANK Ligand; Severity of Illness Index; Spine; Spondylitis, Ankylosing; Tartrate-Resistant Acid Phosphatase; Treatment Outcome; Tumor Necrosis Factor-alpha; Young Adult

Osteoporosis is one of the recognized features of AS. It is known that RANK ligand (RANKL), which binds to RANK, can cause the activation of bone resorption. Osteoprotegerin (OPG) also competes with RANK by binding to RANKL and inhibiting bone absorption. Therefore, we designed a case-control study to evaluate the association between occurrence and clinical features of AS and RANK, RANKL and OPG genetic polymorphisms.. A total of 330 AS patients and 330 age- and gender-matched controls were recruited. PCR-restriction fragment length polymorphism was applied to identify RANK C575T, RANKL C-290T and OPG G1181C genotypes.. OPG GG genotype carriers had an elevated risk of AS compared with those with the GC and CC genotypes (matched odds ratio 1.74; 95% CI 1.26, 2.40). Age of symptom onset and frequency of peripheral arthritis significantly differed among AS patients by OPG G1181C genotypes. HLA-B27(+) patients with the OPG C allele had the earliest age of symptom onset [mean (s.d.) 26.6 (9.6) years], followed by HLA-B27(+) patients with the OPG G allele [32.6 (12.2) years], HLA-B27(-) patients with the OPG G allele [38.1 (13.6) years] and HLA-B27(-) patients with the OPG C allele [38.6 (9.8) years]. CONCLUSION. OPG G1181C polymorphism may be associated with AS development and clinical manifestations.

Topics: Adult; Age of Onset; Bone Resorption; Case-Control Studies; Female; HLA-B27 Antigen; Humans; Logistic Models; Male; Middle Aged; Osteoporosis; Osteoprotegerin; Polymorphism, Genetic; RANK Ligand; Spondylitis, Ankylosing

New bone formation of the spine is a typical feature of ankylosing spondylitis (AS). It is unknown whether new bone formation is part of a physiological repair process or a unique pathological entity of the disease.. We analyzed zygapophyseal joints from patients with AS and osteoarthritis (OA) undergoing spinal surgery for rigid hyperkyphosis (AS) or radiculopathy caused by severe OA. In 17 patients with AS, 11 with OA, and 5 controls we performed immunohistochemical analysis of osteoprotegerin (OPG), nuclear factor-kappaB ligand (RANKL), and osteocalcin (OC) expression in osteoblasts and determined the trabecular thickness in AS and OA patients and controls. Osteoclasts were detected by tartrate-resistant alkaline phosphatase (TRAP) staining.. Trabecular thickness was significantly lower in patients with AS compared to OA (p = 0.01). The absolute number of CD56+ osteoblasts (p < 0.001) and OC+ (p = 0.002), OPG+ (p = 0.003), and RANKL+ osteoblasts (p = 0.03) in AS patients was also significantly lower than in OA patients. The percentages of OC+, OPG+, and RANKL+ osteoblasts did not differ between AS and OA (p > 0.05 in all cases). In controls, the percentages of OPG+ (p = 0.013) and OC+ (p = 0.034) but not RANKL+ (p > 0.05) osteoblasts were significantly lower compared to AS patients. The frequency of TRAP+ osteoclasts in AS patients was significantly lower compared to OA (p < 0.001), but higher compared to controls.. Immunohistochemical analysis of zygapophyseal joints suggested that osteoblast activity is similar in AS and OA, indicating that new bone formation is possibly a physiological function of repair in both diseases.

Topics: Adult; Alkaline Phosphatase; Female; Humans; Immunohistochemistry; Male; Middle Aged; Osteoarthritis; Osteoblasts; Osteocalcin; Osteoclasts; Osteoprotegerin; RANK Ligand; Spondylitis, Ankylosing; Statistics, Nonparametric; Zygapophyseal Joint

The objective of the study was to investigate the role of receptor activator of nuclear factor-kappaB ligand (RANKL) and osteoprotegerin (OPG) in ankylosing spondylitis (AS). Serum levels of soluble RANKL (sRANKL) and OPG were measured in 42 AS patients and 26 healthy controls. We evaluated the AS patient's disease activity, functional ability, global assessment, and physical mobility and tested markers of systemic inflammation, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels. Serum levels of sRANKL [mean (SD), 4.75 (1.88) vs. 3.70 (1.14) pmol/l, p = 0.015] and OPG [mean (SD), 5.18 (1.19) vs. 4.52 (0.85) pmol/l, p = 0.026] were significantly higher in the 42 AS patients than the 26 healthy controls. Interestingly, serum OPG levels correlated significantly with ESR (r = 0.417, p = 0.007), CRP (r = 0.524, p < 0.001), tragus-to-wall distance (r = 0.556, p < 0.001), fingertip-to-floor distance (r = 0.423, p = 0.007), and occiput-to-wall distance (r = 0.465, p = 0.002) and correlated inversely with modified Schober index (r = -0.525, p = 0.001), cervical rotation (r = -0.403, p = 0.022), lateral lumbar flexion (r = -0.587, p < 0.001), and chest expansion (r = -0.553, p < 0.001). Moreover, in the AS patients with higher (> or =4.925 pmol/l, n = 21) serum OPG levels, there were significant increases in the tragus-to-wall distance (p = 0.007), fingertip-to-floor distance (p = 0.023), and CRP levels (p = 0.014) and decreased in the modified Schober index (p = 0.012), lateral lumbar flexion (p = 0.019), and chest expansion (p = 0.005). Serum levels of sRANKL and OPG are increased in the AS patients and may participate in the disease process of AS. Production of OPG has association with poor physical mobility and may reflect systemic inflammation in AS.

Topics: Adult; Blood Sedimentation; C-Reactive Protein; Female; Humans; Inflammation; Male; Middle Aged; Osteoprotegerin; Range of Motion, Articular; RANK Ligand; Seveso Accidental Release; Spondylitis, Ankylosing; Statistics, Nonparametric

To examine the effects of infliximab on bone resorption by osteoclast precursor cells (OCPs) in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS) and to compare the results with changes in disease activity.. Before and during 24 weeks of infliximab treatment, peripheral blood mononuclear cells of 9 RA and 10 AS patients were seeded onto ivory wafers and adherent cells, including OCPs, were grown in medium promoting osteoclast differentiation. Bone resorption was evaluated morphometrically and correlated to disease activity. A total of 19 healthy individuals were studied in parallel. In addition, biochemical bone markers were assessed in all patients at baseline and after 24 weeks.. OCPs from RA patients showed a higher bone resorption at baseline when compared to AS patients. Blocking of tumour necrosis factor (TNF)alpha with infliximab resulted in a strong reduction of bone resorption by OCPs in both cohorts and occurred faster in RA compared to AS patients. This inhibition coincided with a reduction of clinical disease activity in both patient cohorts and with an increase of serum osteocalcin levels and a relative decrease of collagen crosslinks in RA compared to AS patients.. These results provide an explanation on the cellular level for the anticatabolic effect of TNF neutralisation on bone. The variation in the kinetics of bone resorption by the OCPs in patients with RA and AS suggests disease-specific differences in the type or in the preactivation of OCPs.

Topics: Adult; Aged; Amino Acids; Antibodies, Monoclonal; Antirheumatic Agents; Arthritis, Rheumatoid; Biomarkers; Bone Resorption; Case-Control Studies; Cells, Cultured; Female; Humans; Infliximab; Male; Middle Aged; Osteocalcin; Osteoclasts; Osteoprotegerin; RANK Ligand; Spondylitis, Ankylosing; Tumor Necrosis Factor-alpha

Ankylosing spondylitis (AS) is characterized by ankylosis of axial joints but osteoporosis is also a well-reported feature. T cells have been implicated as a source of receptor activator of NFkappaB ligand (RANKL) in inflammatory bone diseases. Hence, we assessed whether T cells in patients with AS act as a source of RANKL too. Therefore, we investigated the expression of RANKL on T cells from 21 patients with AS by flow cytometry. Bone mineral density (BMD) was evaluated by quantitative computer tomography (QCT) and dual X-ray absorptiometry (DXA) and correlated with serum levels of osteoprotegerin (OPG) and RANKL. BMD was decreased in 45% of all patients when measured with DXA (48% with QCT) and correlated negatively with OPG. Expression of intracellular RANKL was increased on CD4+ (84 vs. 70%) and CD8+ (85.2 vs. 65.3%, P < 0.05) T cells in patients with AS, whereas expression of membrane-bound RANKL was significantly lower (CD4+: 2.2 vs. 8.5% and CD8+: 0.7 vs. 3.2%, P < 0.01). Our results indicate that surface and intracellular RANKL production is differentially regulated on T cells of patients with AS.

Topics: Absorptiometry, Photon; Adult; Aged; Bone Density; Bone Diseases, Metabolic; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Female; Flow Cytometry; Humans; Male; Middle Aged; Osteoporosis; Osteoprotegerin; RANK Ligand; Receptors, Cell Surface; Spondylitis, Ankylosing

Topics: Antirheumatic Agents; Biomarkers; Bone Matrix; Bone Morphogenetic Protein 7; Bone Morphogenetic Proteins; Bone Remodeling; Etanercept; Humans; Immunoglobulin G; Macrophage Colony-Stimulating Factor; Matrix Metalloproteinase 3; Osteoprotegerin; Receptors, Tumor Necrosis Factor; Spondylitis, Ankylosing; Transforming Growth Factor beta; Treatment Outcome

To assess bone mineral density (BMD), serum levels of soluble receptor activator of nuclear factors-kappaB ligand (sRANKL) and osteoprotegerin (OPG) in patients with ankylosing spondylitis (AS), and to determine their relationships with disease activities.. Serum levels of sRANKL and OPG in AS were measured by sandwich enzyme-linked immunosorbent assay. The disease activities were determined using Bath Ankylosing Spondylitis Disease Activity Score Index, Bath Ankylosing Spondylitis Functional Index , Bath Ankylosing Spondylitis Metrology Index and Bath Ankylosing Spondylitis Patient Global Score. BMD of femur and lumbar spine was measured by dual energy X-ray absorptiometry. Radiological grading was determined by New York criteria for sacroiliitis and modified Stoke Ankylosing Spondylitis Spine Score.. Osteoporosis and osteopaenia of femoral neck were found in 33 and 41% of patients, respectively. BMD of femoral neck showed negative correlation with disease activity indexes, erythrocyte sedimentation rate and C-reactive protein. The serum sRANKL levels and the ratio of sRANKL to OPG were significantly higher in patients with AS than those of controls. The sRANKL/OPG ratio tended to increase in patients with reduced BMD and radiological findings of active inflammation.. About 74% of AS patients have reduced BMD and this change reflects disease activity. Serum sRANKL levels and sRANKL/OPG ratios are up-regulated in patients with AS and have relationship with BMD and radiological changes. These results suggest that the imbalance between RANKL and OPG might be involved in the pathogenesis and clinical courses of osteoporosis in AS.

Topics: Absorptiometry, Photon; Acute Disease; Adolescent; Adult; Biomarkers; Bone Density; Case-Control Studies; Female; Femur Neck; Humans; Interleukin-17; Male; Middle Aged; Osteoporosis; Osteoprotegerin; RANK Ligand; Spondylitis, Ankylosing; Tumor Necrosis Factor-alpha

To evaluate bone metabolism in patients with ankylosing spondylitis (AS) and test the hypothesis that osteoprotegerin (OPG) serum concentrations are correlated with the severity of bone loss as assessed by bone mineral density (BMD) and biochemical markers of bone turnover. Osteoporosis occurs frequently in patients with AS and OPG represents a soluble decoy receptor that neutralizes receptor activator of nuclear factor-kB ligand (RANKL), an essential cytokine for osteoclast function.. Clinical data, radiographs of the spine, BMD of lumbar spine and the femur, biochemical markers of bone turnover, and serum levels of OPG were evaluated in 264 patients with AS (72% men) and 240 age-matched healthy controls (76% men).. OPG serum levels were significantly lower in patients with AS compared to controls (1.84 +/- 1.15 vs 3.54 +/- 2.18 pmol/l, p < 0.001), and in contrast to controls, were not positively correlated with age. In addition, BMD of the hip and the femoral neck were significantly lower in patients with AS than in controls. There were positive correlations in patients with AS between BMD of the femoral neck and free testosterone serum levels in men and free estradiol serum levels in women, respectively. Patients with AS and osteoporosis had higher biochemical markers of bone resorption and inflammatory activity.. Bone loss in patients with AS is associated with low sex steroid hormone serum levels, high biochemical markers of bone resorption and inflammatory activity, low OPG serum levels, and lack of compensatory age-related increase of OPG serum levels.

Topics: Adolescent; Adult; Aged; Bone and Bones; Bone Density; Estradiol; Female; Glycoproteins; Gonadal Steroid Hormones; Humans; Male; Middle Aged; Osteoporosis; Osteoprotegerin; Radiography; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Spondylitis, Ankylosing; Testosterone

To test if markers of bone metabolism are altered in patients with seronegative spondyloarthropathies (SSpA).. We studied biochemical markers of bone resorption and bone formation, osteoprotegerin (OPG), and bone mineral density (BMD) in patients with psoriatic arthritis (PsA), ankylosing spondylitis (AS), and reactive arthritis (ReA) and healthy volunteers.. The bone resorption markers urinary deoxypyridinoline and crosslinked telopeptide of collagen-I were significantly increased in patients with AS, PsA, and ReA; in PsA they correlated with the acute phase response (C-reactive protein and erythrocyte sedimentation rate). The bone formation markers were divergent: bone-specific alkaline phosphatase was increased in PsA, but not in AS or ReA. Osteocalcin levels were only elevated in AS. Serum levels of OPG were significantly increased in both AS and PsA. Dual energy x-ray absorptiometry (DEXA) measurements of lumbar spine and femoral neck revealed osteopenia in patients with AS, whereas the DEXA distribution was within normal range in PsA.. Our data indicate high and, particularly in AS, unbalanced bone turnover in SSpA, consistent with the decrease in BMD found in patients with AS.

Topics: Absorptiometry, Photon; Adolescent; Adult; Aged; Amino Acids; Arthritis, Psoriatic; Arthritis, Reactive; Biomarkers; Bone Density; Bone Resorption; Cohort Studies; Female; Glycoproteins; Humans; Male; Middle Aged; Osteocalcin; Osteoprotegerin; Probability; Prognosis; Prohibitins; Prospective Studies; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Risk Assessment; Sensitivity and Specificity; Severity of Illness Index; Spondylitis, Ankylosing; Tumor Necrosis Factor-alpha

Topics: Amino Acids; Glycoproteins; Humans; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Spondylitis, Ankylosing

Rheumatic diseases are often associated with changes in bone metabolism. Excessive production and release of cytokines and other growth factors due to inflammation, e.g. tumor necrosis factor-alpha (TNF-alpha), receptor activator of NF-kappaB ligand (RANKL), interleukins such as IL-1 and IL-6, may cause alterations in bone homeostasis leading to bone degradation. Other components such as osteoprotegerin (OPG) and possibly the ligand-receptor pair hepatocyte growth factor (HGF) and c-met may counteract this destruction, we have measured the levels of OPG, and HGF c-met, in serum, synovial fluid (SF), and cartilage from patients with rheumatoid arthritis (RA) and other arthritides. We found a) elevated levels of both OPG and HGF in SF from RA patients relative to arthritides of other causes, b) increased levels of both OPG and HGF in SF from seropositive RA patients (RA+) compared to seronegative RA patients (RA-), c) elevated levels or both OPG and HGF in serum from RA patients compared to healthy controls, d) no correlation between severity of inflammation and levels of OPG or HGF, and e) presence of HGF c-met in both cartilage and synovial tissue. The most significant elevations of OPG and HGF were found in patients with RA, the rheumatic disease most frequently associated with the development of secondary osteoporosis.

Topics: Adult; Arthritis, Rheumatoid; Cartilage, Articular; Enzyme-Linked Immunosorbent Assay; Female; Fluorescent Antibody Technique, Indirect; Glycoproteins; Hepatocyte Growth Factor; Humans; Male; Middle Aged; Osteoarthritis; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Spondylitis, Ankylosing; Synovial Fluid