title: Cell-mediated immune response in the diseased joints in patients with reactive arthritis.
abstract: To evaluate the level of lymphocyte activation in reactive and rheumatoid arthritis, density gradient-isolated, synovial fluid mononuclear cells were stained with a panel of antisera directed at lymphocyte activation markers using an avidin-biotin-peroxidase complex (ABC) method. More specifically, we studied the expression of immune response-associated class II HLA antigen (Ia), of receptors for interleukin 2 (Tac) and transferrin (T9), as well as of gp 40/80 glycoprotein (4F2). Although Ia+ cells formed about 60% of all the synovial fluid mononuclear cells in both disease conditions, the proportion of Tac+ (33 +/- 4% vs 3 +/- 1%, P less than 0.001), T9+ (34 +/- 4% vs 5 +/- 2%, P less than 0.001), and 4F2+ (48 +/- 6% vs 3 +/- 2%, P less than 0.001) cells was high only in reactive arthritis. All the patients who had reactive arthritis followed a favourable clinical course during the 4-month-long prospective follow-up, whereas disease activity was stable in patients with rheumatoid arthritis. These findings suggest that the diseased joints in reactive arthritis are a site for an active, but normally down-regulated, cell-mediated immune response.
mesh_terms: D000911:Antibodies, Monoclonal; D001170:Arthritis, Infectious / Q000276:immunology*; D001172:Arthritis, Rheumatoid / Q000276:immunology; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006801:Humans; D007111:Immunity, Cellular; D008213:Lymphocyte Activation; D011956:Receptors, Cell Surface / Q000032:analysis; D011971:Receptors, Immunologic / Q000032:analysis; D015375:Receptors, Interleukin-2; D011990:Receptors, Transferrin; D013582:Synovial Fluid / Q000276:immunology*
chemical_list: D000911:Antibodies, Monoclonal; D000949:Histocompatibility Antigens Class II; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D011990:Receptors, Transferrin