SYNOVIAL-FLUID ANTIGEN-PRESENTING CELL-FUNCTION IN RHEUMATOID-ARTHRITIS

We have previously demonstrated enhanced synovial fluid (SF) antigen-p resenting cell (APC) function in inflammatory arthritis patients selec ted on the basis of marked SF mononuclear cell (MNC) responsiveness to reactive arthritis-associated bacteria (Clin Exp Immunol 1990; 79:189 -94). In this study we have assessed whether similarly enhanced synovi al APC function is present in other inflammatory arthritis patients by using two assay systems to study 18 rheumatoid arthritis patients who se MNC responsiveness had not been determined in advance. We demonstra te that rheumatoid SF APC are much more potent than peripheral blood ( PB) APC in stimulating the responses of autologous PB T cells to a ran ge of recall antigens. In addition, SF APC are shown to be efficient s timulators of the antigen-specific responses of MHC-compatible, cloned T cells. Enhanced synovial APC function is thus likely to be a genera l feature of inflammatory arthritis and may play an important role in its pathogenesis.