Objective. To determine the effect of pulse methyprednisolone (PMP 1000 mg) on the expression of monocyte chemoattractant protein (MCP)-1 and macrophage inflammatory protein (MIP)-1 alpha in rheumatoid synovial membrane.Methods. Seven patients with rheumatoid arthritis (RA) were studied. Arthroscopically-directed synovial biopsies were taken before and 24 hours after treatment with intravenous PMP. Synovial membranes were stained by immunohistochemical techniques with monoclonal antibodies against MCP-1. MIP-1 alpha and CD68 (a macrophage marker). Quantitation of staining was performed by computer-assisted color video image analysis.Results. PMP therapy was associated with a rapid (within 24 hours) and substantial decrease in the expression of MCP-1 and MIP-1 alpha expression by a mean of 55% (p = 0.05) and 45% (p = 0.03), respectively, with no effect on CD68 expression in the synovial lining layer. There was no significant change in MCP-1, MIP-1 alpha or CD68 expression in the synovial sublining.Conclusion. PMP therapy rapidly reduces MCP-1 and MIP-1 alpha levels in the synovial lining layer without a fall in macrophage numbers. It thus appears that the initial effect of PMP is that of reducing macrophage activation.

OBJECTIVE:To investigate the effects of a 1000 mg i.v. pulse of methylprednisolone succinate (pulse therapy) on the expression of matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases-1 (TIMP-1) in the synovial membrane of the knee in patients with rheumatoid arthritis (RA).METHODS:Sequential arthroscopic biopsies of the knee were taken before and 24 h after pulse therapy (11 patients), at disease relapse (three patients) and after retreatment with pulse therapy (one patient). Immunoperoxidase staining for MMP-1 (interstitial collagenase), MMP-3 (stromelysin-1) and TIMP-1 was performed and the immunoreactive staining quantified by colour video image analysis.RESULTS:In the synovial lining layer, MMP-1 and TIMP-1 immunostaining was reduced by a mean of 47% (P = 0.02) and 72% (P = 0.05), respectively, 24 h after pulse methylprednisolone therapy. In the synovial sublining layer, MMP-1 was reduced by a mean of 51% (P = 0.08) and TIMP-1 by a mean of 73% (P = 0.02) 24 h after pulse methylprednisolone therapy. There was no change in MMP-3 staining in the synovial lining or sublining layer.CONCLUSIONS:High-dose pulse methylprednisolone therapy is associated with a rapid (within 24 h) and substantial decrease in the expression of MMP-1 and TIMP-1 but not MMP-3 in the synovial membrane in RA.

Microscopic measurement of inflammation in synovial tissue may be important in studies of clinical status, prognosis and response to treatment. The aim of this study was to compare quantitative microscopic analysis of inflammation with a semiquantitative grading system in rheumatoid arthritis (RA) synovial membrane. Knee synovial membrane samples from 16 patients with RA, including paired samples taken before and after treatment in nine patients, were immunostained with anti-CD68 and anti-CD3 monoclonal antibodies using standard techniques. The intensity of macrophage and T-lymphocyte infiltration was measured both by quantitative and semiquantitative techniques, and the results were compared. In a cross-sectional comparison, both methods correlated significantly for lining layer macrophage infiltration, as well as sublining layer macrophage and T-cell infiltration. However, in some patients demonstrating a clinical response to treatment, semiquantitative analysis lacked sensitivity to biologically relevant changes in mononuclear cell infiltration. These observations have important implications for future studies of therapeutic modalities.

OBJECTIVE To establish the presence of inflammation in and cytokine production by synovial membranes from patients with various stages of early osteoarthritis (OA), with knee pain, normal knee radiographs, and arthroscopic evidence of chondral damage. METHODS Synovial membrane samples were obtained from the knees of 63 patients at the time of arthroscopy for unexplained knee pain or at the time of joint replacement surgery. Evaluations of synovial membrane variables including thickness of lining layer, vascularity, and inflammatory cell infiltrate were by a blinded observer. In a subset of 20 patients, production of interleukin 1 alpha (IL-1 alpha), interleukin 1 beta (IL-1 beta), tumor necrosis factor alpha (TNF-alpha), and IL-1 receptor antagonist (IL-1ra) at the mRNA and protein levels was determined using in situ hybridization with biotin labeled ribo-probes and immunohistochemistry. RESULTS There was evidence of thickening of the lining layer, increased vascularity, and inflammatory cell infiltration in synovial membranes from patients with all grades of OA, with the most marked changes seen in synovial tissue from patients with advanced grades of OA. Similarly, production of IL-1 alpha, IL-1 beta, and TNF-alpha was present in synovial membranes from all patients with OA, irrespective of the degree of articular cartilage damage. There was a trend to decreased levels of IL-1ra in synovial membranes from patients with OA that did not attain statistical significance. Similarly, there was a decrease in the ratio of IL-1ra to IL-1 alpha and beta with increasing grades of OA. CONCLUSION Chronic inflammatory changes with production of proinflammatory cytokines are a feature of synovial membranes from patients with early OA, with the most severe changes seen in patients at the time of joint replacement surgery resembling those seen in rheumatoid arthritis. This low grade synovitis results in the production of cytokines that may contribute to the pathogenesis of OA.

We describe the cellular infiltrate and cytokine profile in sequential synovial membrane biopsies from a patient with acute followed by chronic synovitis after intravesical bacillus Calmette-Guérin (BCG) therapy for an in situ transitional cell carcinoma of the bladder. Histological and immunohistochemical analysis of 3 synovial biopsies were done sequentially over a 9 month period. The patient was HLA-B27 positive, but HLA-DR4 negative, and did not have the "shared epitope." Unlike other cases, this patient's arthritis did not respond initially to nonsteroidal antiinflammatory drugs and was exacerbated by corticosteroid therapy. The synovitis took a neutrophilic form, with marked synovial membrane content of interleukin 8 (IL-8) and tumor necrosis factor alpha (TNF-alpha). It subsequently developed into chronic lymphoplasmacytoid synovitis, similar to rheumatoid arthritis (RA), with decreased IL-8 but continuing IL-1 and TNF-alpha production in the synovial membrane. The synovitis resolved to a fibrotic synovium with residual thickening of the synovial lining layer and continued production of TNF-alpha. Thus, during the evolution of this arthritis, the synovial layer and continued production of TNF-alpha. Thus, during the evolution of this arthritis, the synovial membrane yielded a cellular infiltrate and cytokine content that had marked similarities with that seen in RA; however, the arthritis eventually remitted spontaneously.

Recently it was shown that tumor necrosis factor-alpha (TNF) receptors on neutrophils may be down-regulated after stimulation with proinflammatory mediators. Since in rheumatoid arthritis neutrophils are likely to encounter these mediators in the circulation, we tested the hypothesis that rheumatoid arthritis neutrophil TNF receptors are down-regulated. Peripheral blood neutrophils from patients with rheumatoid arthritis and healthy subjects were compared with respect to their TNF binding activity and ability to be primed by TNF. There were no differences between rheumatoid arthritis and control neutrophils in receptor-mediated TNF binding, superoxide release in response to agonist, and TNF priming of this respiratory burst or in the ability to degrade cartilage in vitro and TNF priming for increased cartilage damage. It is evident that rheumatoid arthritis blood neutrophils retain the ability to bind TNF and can be primed by TNF for increased oxygen radical production and augmented cartilage damage. These findings further implicate the role of neutrophils in the pathogenesis of arthritis.