The effects of interferon-beta treatment of synovial inflammation and expression of metalloproteinases in patients with rheumatoid arthritis.

OBJECTIVE: Interferon-beta (IFNbeta) treatment is emerging as a potentially effective form of therapy in various immune-mediated conditions. This study evaluated the effects of IFNbeta therapy on the cell infiltrate, cytokine profile, and expression of metalloproteinase 1 (MMP-1) in synovial tissue from patients with rheumatoid arthritis (RA). To further assess the mechanism of action, in vitro experiments were conducted to determine the effects of IFNbeta on the production of MMP-1, MMP-3, tissue inhibitor of metalloproteinases 1 (TIMP-1), and prostaglandin E2 (PGE2) by human fibroblast-like synoviocytes (FLS). METHODS: Eleven patients were treated for 12 weeks with purified natural fibroblast IFNbeta (Frone; Ares-Serono, Geneva, Switzerland) subcutaneously 3 times weekly with the following dosages: 6 million IU (n = 4), 12 million IU (n = 3), and 18 million IU (n = 4). Synovial biopsy specimens were obtained by needle arthroscopy at 3 time points: directly before and at 1 month and 3 months after initiation of treatment. Immunohistologic analysis was performed using monoclonal antibodies specific for the following phenotypic markers and mediators of joint inflammation and destruction: CD3, CD38, CD68, CD55, tumor necrosis factor alpha (TNFalpha), interleukin-1beta (IL-1beta), IL-6, MMP-1, and TIMP-1. In addition, we measured the production of MMP-1, MMP-3, TIMP-1, and PGE2 by RA FLS and dermal fibroblasts in the presence and absence of IFNbeta. RESULTS: A statistically significant reduction in the mean immunohistologic scores for CD3+ T cells and the expression of MMP-1 and TIMP-1 at 1 month, CD38+ plasma cells and the expression of IL-6 at 3 months, and the expression of IL-1beta at both 1 and 3 months was observed in synovial tissue after IFNbeta treatment. The scores for CD68+ macrophages and TNFalpha expression also tended to decrease, but the differences did not reach statistical significance. The in vitro experiments revealed inhibition of MMP-1, MMP-3, and PGE2 production by RA FLS, whereas TIMP-1 production was only slightly decreased. These effects were more consistent in RA FLS than in dermal fibroblasts. CONCLUSION: The changes in synovial tissue after IFNbeta treatment and the in vitro data support the view that IFNbeta therapy has immunomodulating effects on rheumatoid synovium and might help to diminish both joint inflammation and destruction. Larger well-controlled studies are warranted to show the efficacy of IFNbeta treatment for RA.

Immunohistological analysis of synovial tissue for differential diagnosis in early arthritis.

OBJECTIVE: An early diagnosis in patients presenting with arthritis is important to provide information about prognosis and to initiate treatment. The objective of this study was to determine which markers applied in immunohistological analysis of synovial tissue (ST) specimens could be used to differentiate rheumatoid arthritis (RA) from other forms of arthritis. METHODS: Synovial biopsies were obtained by blind needle techniques from 95 patients with early arthritis. After follow-up of at least 2 yr to verify the diagnosis, the patients could be classified as follows: RA (n=36), undifferentiated arthritis (UA; n=21), osteoarthritis (OA; n=17), reactive arthritis (ReA; n=10), ankylosing spondylitis (AS; n=3), psoriatic arthritis (PsA; n=2) and crystal-induced arthritis (CA; n=6). ST sections were analysed by immunohistochemistry using monoclonal antibodies against CD3, CD4, CD8, CD22 (B cells), CD38 (plasma cells), CD68 (macrophages) and CD55 (fibroblast-like synoviocytes). RESULTS: Logistic regression analysis revealed that the higher scores for the numbers of CD38+ plasma cells and CD22+ B cells in RA were the best discriminating markers comparing RA to non-RA patients (CD38: P=0.0001; CD22: P<0.05). Polychotomous regression analysis comparing three diagnostic categories (1: RA; 2: UA, ReA, AS and PsA; 3: OA and CA) also identified the score for the number of CD38+ plasma cells (P<0.0001) as well as the numbers of CD68+ macrophages in the synovial sublining (P=0.05) as discriminating markers. CONCLUSION: The results suggest that immunohistochemical analysis of ST specimens from early arthritis patients can be used to differentiate RA from non-RA patients. The numbers of plasma cells, B cells and macrophages are especially increased in ST of patients with RA. Future studies in early arthritis patients with clinical features which do not allow an immediate confident diagnosis may clarify the role of this test system in differential diagnosis.

Expression of the thioredoxin-thioredoxin reductase system in the inflamed joints of patients with rheumatoid arthritis.

OBJECTIVE: To examine the expression of the thioredoxin (TRX)-thioredoxin reductase (TR) system in patients with rheumatoid arthritis (RA) and patients with other rheumatic diseases. METHODS: Levels of TRX in plasma and synovial fluid (SF) were measured using enzyme-linked immunosorbent assay. Cellular distribution of TRX was determined by flow cytometry and histochemistry. Cellular expression of TR was studied by in situ messenger RNA (mRNA) hybridization. The effect of oxidative stress and tumor necrosis factor alpha (TNF alpha) on TRX expression by cultured rheumatoid fibroblast-like synoviocytes was studied. RESULTS: Significantly increased TRX levels were found in the SF from 22 patients with RA, when compared with plasma levels in the same patients (P < 0.001) and compared with SF TRX levels in 15 patients with osteoarthritis (P < 0.001), 13 patients with gout (P < 0.05), and 9 patients with reactive arthritis (P < 0.0001). The presence of TRX could be demonstrated within the SF-derived mononuclear cells and synovial tissue (ST) of RA patients. Concordantly, expression of TR mRNA was observed in the ST of these patients. Stimulation of synovial fibroblast-like synoviocytes with either H2O2 or TNF alpha induced an increase in the production of TRX. CONCLUSION: The data demonstrate significantly increased concentrations of TRX in the SF and ST of RA patients when compared with the levels in patients with other joint diseases. Evidence is presented that the local environment in the rheumatic joint contributes to increased TRX production. Based on its growth-promoting and cytokine-like properties, it is proposed that increased expression of TRX contributes to the disease activity in RA.

Analysis of serial synovial biopsies in patients with rheumatoid arthritis: description of a control group without clinical improvement after treatment with interleukin 10 or placebo.

OBJECTIVE: Analysis of serial synovial biopsy specimens is increasingly used as an outcome measure for the evaluation of therapeutic interventions. However, observations in placebo treated groups are scarce. We describe the immunohistologic features of the synovium in placebo treated patients with RA and in those who received interleukin 10 (IL-10). METHODS: Ten patients with active RA received dosages of either placebo (n = 7) or 5 microg/kg (n = 1) or 10 microg/kg (n = 2) of recombinant human IL-10 (rhIL-10; SCH 52000, Schering-Plough, Kenilworth, NJ, USA) daily for 28 consecutive days. Synovial biopsy specimens from the knee joint were obtained by needle arthroscopy before and 4 weeks after initiation of treatment. Immunohistochemistry was performed using monoclonal antibodies specific for the following surface markers and cytokines: CD3, CD4, CD8, CD38, CD68, CD55, IL-1beta, IL-6, and tumor necrosis factor-alpha. RESULTS: No patient exhibited clinical improvement after treatment with placebo or any rhIL-10 dosage. Microscopic analysis of synovial tissue revealed no significant change in the scores for infiltration by inflammatory cells or in the scores for the expression of cytokines after treatment. CONCLUSION: Studies of serial synovial biopsies from patients treated with placebo or IL-10 revealed no changes in immunohistologic scores. This suggests that the biopsy procedure itself has no effect on the features of the synovium.