title: Evidence for enhanced interleukin 2 (IL-2) secretion and IL-2 receptor presentation by synovial fluid lymphocytes in rheumatoid arthritis.
abstract: Synovial fluid lymphocytes (SFL) and peripheral blood lymphocytes (PBL) from patients with rheumatoid arthritis (RA) and reactive oligoarthritis were investigated for activated T cells (Ia+SIg-), IL-2 receptor bearing cells (Tac+) and IL-2 production in vivo and in vitro. In contrast to negative results with blood, the synovial fluid of the arthritic joints contains considerable amounts of IL-2 activity (median: 11.8 mu/ml), elevated proportions of Ia+SIg- activated T cells (median: 12.5%) and of IL-2 receptor bearing cells (median: 2.5%). In vitro, after stimulation with several Concanavalin A (Con A) doses, SFL develop proportions of IL-2 receptor cells comparable to PBL. Furthermore, they produce higher values of IL-2 activity than comparable PBL cultures. The proportions of Ia+SIg- activated T cells increase only moderately after Con A stimulation compared to in vivo data, indicating different activated T cell subsets in the synovial fluid (Ia+SIg-, Tac+). The findings are discussed as an expression of an acute hyperactivation of lymphocytes in an inflamed joint.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D011971:Receptors, Immunologic / Q000032:analysis*; D015375:Receptors, Interleukin-2; D013582:Synovial Fluid / Q000276:immunology*; D013601:T-Lymphocytes / Q000187:drug effects / Q000276:immunology*
chemical_list: D007376:Interleukin-2; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D003208:Concanavalin A