Search for antigen in rheumatoid synovial macrophages.

Peripheral blood monocytes and synovial macrophages obtained from 21 patients with rheumatoid arthritis and from 13 controls were cultured with autologous peripheral blood lymphocytes and stimulation measured by thymidine uptake. Rheumatoid macrophages and monocytes induced a small but significant degree of lymphocyte transformation, and those from the controls did not. The degree of stimulation appears to be more consistent with the nonspecific effect of lymphocyte activating factor, rather than with the presence of a specific synovial antigen.