Suppression and stimulation of immunoglobulin synthesis by agents present in rheumatoid synovial effusions.

Synovial effusions from 14 patients with rheumatoid arthritis contain factors capable of enhancing and suppressing the production of immunoglobulin when added to normal peripheral lymphocyte cultures in vitro. Utilizing a radioactive immune coprecipitation technique it could be demonstrated that enhancement was observed upon addition of relatively small amounts of synovial fluid, while addition of higher amounts resulted in suppression of immunoglobulin synthesis. Nine of ten non-rheumatoid joint effusions showed neither enhancing nor suppressing activities. The possible relationship of these events to lymphokine production in the joint is discussed.