The influence of synovial fluid from patients with rheumatoid arthritis on the proliferation of peripheral blood lymphocytes and the prostanoid release from monocytes.

The present study was designed to characterize leukocytes of patients with rheumatoid arthritis (RA) with regard to proliferation of peripheral blood lymphocytes (PBL) and prostanoid release from circulating monocytes (M phi. Compared to cells of healthy individuals, PBL from RA patients exhibited a reduced mitogenic response to concanavalin A (Con A) which was associated with an increased capacity of circulating M phi to synthesize PGE and thromboxane B2 (TXB2). Addition of synovial fluid exudates of RA patients (RA-SFE) to peripheral blood leucocyte cultures produced three effects: A spontaneous proliferation of normal and RA-PBL, a reduction of the Con A response of normal and RA-PBL, a reduction of the Con A response of normal and RA-PBL, and an enhanced release of PGE and TXB2 from RA-M phi only. To elucidate the cellular origin of these activities, normal and RA-PBL were incubated with supernatants (SNT) os synovial cell cultures from RA patients and patients with non-RA joint diseases. SNT from Con A-stimulated synovial lymphocytes of both RA and control patients induced a spontaneous proliferation of normal and RA-PBL. In contrast, SNT from non-lymphoid adherent synovial cells of RA and control patients reduced the Con A response of normal and RA-PBL but a striking difference was noted in that an enhanced PGE and TXB2 release occurred only from M phi of RA patients.