rheumatoid arthritis and osteoarthritis

Objective-To measure the amounts of interleukin-1 receptor antagonist (IL-Ira) protein produced by cultured synovial cells obtained from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Methods-Synovial cells obtained from patients with either RA or OA were cultured and the supernatants were measured for IL-lra by enzyme linked immunosorbent assay. Results-The synovial celis obtained from patients with RA produced significantly smaller amounts of IL-Ira than did those obtained from patients with OA, in a late passage (third to fifth) without stimulation and a first passage both with and without stimulation (p < 0 025, respectively). In addition, when the patients with RA were divided into two groups according to the maximum number of lining cell layers, the amounts of IL-Ira produced by the proliferative type were smaller than those produced by the less proliferative type (p < 0.025). Conclusions-The above findings suggest that IL-Ira production in RA synovial cells is suppressed, and that reduced IL-Ira protein production is one of the causes which leads to the proliferation of lining cells and persistent joint inflammation. RA and osteoarthritis (OA) were measured by an enzyme linked immunosorbent assay (ELISA). Patients and methods Synovial tissue specimens were obtained from 18 patients (10 with RA and eight with OA) at the time of knee joint replacement. Each patient satisfied the diagnostic criteria of the American College of Rheumatology.7 8 All RA patients were treated with prednisolone, disease modifying antirheumatic drugs (DMARDs) and non-steroidal anti-inflammatory drugs (NSAIDs). All OA patients took NSAIDs without taking prednisolone. HISTOLOGICAL ANALYSIS OF SYNOVIAL