Inflammatory cytokines and enzymes in synovial fluid of patients with rheumatoid arthritis and other arthritides.

Cytokines and lysosomal enzymes, which are produced by inflammatory cells, play a role in inflammation. We have found that synovial fluid (SF) in rheumatoid and septic arthritis contained a large number of white blood cells (WBCs) and high levels of cytokines and enzymes, while in contrast the SF of osteoarthritis and traumatic arthritis did not contain significant amounts. Measurements of WBCs, cytokines and enzymes in SF are useful for evaluating clinical disease activity. Assays for WBCs and enzymes are simple and rapid when compared to those for cytokines.