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OBJECTIVE: Osteocytes are considered to be sensors of bone damage and regulators of bone mass by specifically expressing sclerostin, an inhibitor of bone formation. The contribution of osteocytes in regulating local bone remodeling in arthritis is unknown. The aim of this study was to investigate the role of osteocytes as contributors to bone remodeling in ankylosing spondylitis (AS). METHODS: Sclerostin expression and osteocyte death were assessed by immunohistochemistry in joints derived from patients with AS, patients with rheumatoid arthritis (RA), and patients with osteoarthritis (OA), as well as from control subjects. In addition, the serum level of sclerostin was assessed by enzyme-linked immunosorbent assay in healthy subjects and patients with AS; this assessment included the longitudinal correlation of sclerostin serum levels and radiographic progression in the spine of patients with AS. RESULTS: Sclerostin expression was confined exclusively to osteocytes. Whereas the majority of osteocytes in healthy individuals and patients with RA were sclerostin positive, expression was significantly reduced in patients with OA and was virtually absent in patients with AS. Moreover, serum levels of sclerostin were significantly lower in patients with AS than in healthy individuals. Importantly, low serum sclerostin levels in patients with AS were significantly associated with the formation of new syndesmophytes (P = 0.007). CONCLUSION: Sclerostin expression is impaired in patients with AS, suggesting a specific alteration of osteocyte function in this disease. A low serum level of sclerostin in the setting of AS is linked to increased structural damage, emphasizing the role of sclerostin in the suppression of bone formation. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Analysis of the histopathologic features of hip arthritis in patients with ankylosing spondylitis (AS) has revealed accumulation of infiltrating mononuclear cells in the bone end plate and presence of hyaline articular cartilage that is not found in areas of total cartilage destruction. This study was undertaken to assess whether chondrocytes attract lymphocytes and whether cartilage chondrocytes from patients with AS have the potential to directly stimulate T cells in an HLA-restricted manner. METHODS: Human HLA-B27+ T cell lines, specific for the Epstein-Barr virus-derived peptide EBNA(258-266), and autologous chondrocytes, serving as nonprofessional antigen-presenting cells (APCs), were available for use in a model system to study chondrocyte functions in femoral head joint cartilage of patients with AS. Peptide functionality of cytotoxic T cells was assessed by flow cytometry, and cellular interactions were detected by fluorescence confocal microscopy. RESULTS: When maintained in an alginate matrix, chondrocytes isolated from the femoral heads of patients with AS constitutively expressed type II collagen and CD80. When pulsed with the EBNA(258-266) peptide, autologous chondrocytes functioned as APCs and, specifically, induced interferon-gamma production in CD8+ T cells. In mixed chondrocyte-T cell cultures, cell-cell contacts were dependent on the presence of the EBNA(258-266) peptide. T cells adjacent to chondrocytes produced perforin and granzyme B; both molecules were found in focal aggregates, a prerequisite for antigen-specific lysis of target cells. CONCLUSION: Antigen presentation through human chondrocytes allows the stimulation of peptide-specific CD8+ T cells. These results indicate that human chondrocytes can act as nonprofessional APCs, and suggest that there is an interferon-gamma-triggered autocrine loop of immune cell-mediated chondrocyte activation in the already inflamed environment. Thus, local HLA-dependent activation of peptide-specific cytotoxic CD8+ T cells by chondrocytes might contribute to inflammatory processes in the spondylarthritides. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Ankylosing spondylitis (AS) is diagnosed late, because radiographs of the sacroiliac joints often do not show definite sacroiliitis at the time of disease onset. The aim of this study was to investigate whether patients without definite radiographically defined sacroiliitis, referred to as nonradiographic axial spondylarthritis (SpA), are different from patients with AS with regard to clinical manifestations and disease activity measures. Moreover, we sought to identify determinants of the development of radiographic sacroiliitis. METHODS: In a cross-sectional analysis of 462 patients, we compared 226 patients with nonradiographic axial SpA (symptom duration

OBJECTIVE: To evaluate the efficacy and safety of golimumab in patients with ankylosing spondylitis (AS) in the GO-RAISE study. METHODS: Patients with active AS, a Bath AS Disease Activity Index (BASDAI) score >/=4, and a back pain score of >/=4 were randomly assigned in a 1.8:1.8:1 ratio to receive subcutaneous injections of golimumab (50 mg or 100 mg) or placebo every 4 weeks. The primary end point was the proportion of patients with at least 20% improvement in the ASsessment in AS (ASAS20) criteria at week 14. RESULTS: At randomization, 138, 140, and 78 patients were assigned to the 50-mg, 100-mg, and placebo groups, respectively. After 14 weeks, 59.4%, 60.0%, and 21.8% of patients, respectively, were ASAS20 responders (P < 0.001). A 40% improvement in the ASAS criteria at week 24 occurred in 43.5%, 54.3%, and 15.4% of patients, respectively. Patients receiving golimumab also showed significant improvement in the physical and mental component summary scores of the Short Form 36 Health Survey, the Jenkins Sleep Evaluation Questionnaire score, the BASDAI score, and the Bath AS Functional Index score, but not the Bath AS Metrology Index score. Through week 24, 85.6% of golimumab-treated patients and 76.6% of patients in the placebo group had >/=1 adverse event, and 5.4% and 6.5% of patients, respectively, had >/=1 serious adverse event. Eight golimumab-treated patients and 1 placebo-treated patient had markedly abnormal liver enzyme values (>/=100% increase from baseline and a value >150 IU/liter), which were transient. CONCLUSION: Golimumab was effective and well tolerated in a large cohort of patients with AS during a 24-week study period. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To evaluate the efficacy and safety of the tumor necrosis factor (TNF) antagonist adalimumab in patients with axial spondylarthritis (SpA) without radiographically defined sacroiliitis refractory to conventional treatment. METHODS: Patients with active axial SpA (n = 46) were randomized to receive placebo or adalimumab at a dosage of 40 mg subcutaneously every other week for 12 weeks, followed by an open-label extension that continued up to week 52. The diagnosis of axial SpA required the presence of 3 of 6 diagnostic criteria, including 2 of the following 3 criteria: inflammatory back pain, HLA-B27 positivity, or acute inflammation of the spine or sacroiliac joints on magnetic resonance imaging, in the absence of radiographic evidence of sacroiliitis. The primary end point was a 40% response according to the improvement criteria of the Assessment of SpondyloArthritis international Society (ASAS40). RESULTS: All 46 patients (22 receiving adalimumab and 24 receiving placebo) completed the 12-week trial; 38 patients completed the extension period to week 52. At week 12, an ASAS40 response was achieved by 54.5% of the adalimumab-treated patients, as compared with 12.5% of the placebo-treated patients (P = 0.004). After switching to adalimumab, a similar degree of efficacy was also achieved by the patients who were initially treated with placebo. Efficacy was maintained in all patients until week 52. Young age at study entry and an elevated C-reactive protein concentration were the best predictors of achieving an ASAS40 response. Serious adverse events occurred in 5 patients, none of which was related to the study drug. CONCLUSION: Adalimumab is the first TNF antagonist to demonstrate good clinical efficacy and safety in patients with axial SpA without radiographically defined sacroiliitis. [ABSTRACT FROM AUTHOR]

OBJECTIVE: In reactive arthritis (ReA), a bacteria-specific T cell response to the triggering microbe is detected in synovial fluid. So far, direct characterization of bacteria-specific T cells and identification of the immunodominant fine specificities remain difficult due to the lack of appropriate techniques. The aim of the present study was to directly determine the fine specificity of CD4+ T cells specific to ReA-associated bacteria-derived protein. METHODS: In 2 patients with Yersinia-induced ReA, live Yersinia Hsp60-specific CD4+ T cells were directly isolated from synovial fluid after stimulation with Yersinia-derived protein Hsp60 using a cytometric cytokine secretion assay. Generated short-term T cell lines were then tested in vitro for their peptide epitope specificity. Also, direct cross-reactivity of one line with Chlamydia- and human-derived Hsp60 was assessed. RESULTS: Generated short-term CD4+ T cell lines were highly antigen-specific and revealed single immunodominant peptide epitopes that were confirmed by direct testing with single peptides in both peripheral blood and synovial fluid cells. Yersinia Hsp60-specific T cells of one patient cross-reacted directly with human Hsp60. CONCLUSION: Our results demonstrate the feasibility of direct assessment of live, potentially pathogenic, antigen-specific interferon-gamma+ CD4+ T cells taken from inflammatory lesions of patients with rheumatic diseases such as ReA. This might have implications not only regarding pathogenesis, but also in the design of new immunotherapies. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Previous histopathologic and magnetic resonance imaging studies suggest that the subchondral bone marrow might be the primary site of inflammation in patients with ankylosing spondylitis (AS) and that this might be reflected by inflammation found in hip joints. The aim of this study was to conduct an immunohistologic assessment of the bone-cartilage interface and subchondral bone marrow in AS patients with hip arthritis. METHODS: We collected femoral heads from patients with AS, osteoarthritis (OA), and rheumatoid arthritis (RA) who were undergoing hip replacement. The subchondral bone marrow and bone-cartilage interface were assessed immunohistochemically by evaluating infiltrating T cells, microvessel density, and osteoclasts. Areas of the femoral head surface with and without cartilage were assessed separately. RESULTS: At sites with surface cartilage, we found subchondral infiltration of CD3+ T cell aggregates at significantly higher numbers in AS patients as compared with OA patients, but not RA patients. At sites of complete cartilage destruction, the frequency of CD3+ T cell aggregates was significantly reduced as compared with sites with cartilage on the surface in AS patients, but not in RA patients. Similar differences were found for CD4+ and CD8+ T cells. Only at sites with surface cartilage, but not those without, angiogenesis and osteoclastic foci in the subchondral bone marrow in AS patients were significantly increased as compared with RA patients and with OA patients. CONCLUSION: These findings suggest that the subchondral bone marrow and bone-cartilage interface are primary sites of inflammation in AS and that cartilage might be necessary for the induction of inflammation. [ABSTRACT FROM AUTHOR]