title: Immunologic studies of rheumatoid arthritis patients treated with methotrexate.
abstract: Immunologic functions of peripheral blood mononuclear cells were studied in rheumatoid arthritis (RA) patients treated with methotrexate (MTX). Spontaneous IgM rheumatoid factor (IgM-RF) synthesis by unstimulated cultured blood mononuclear cells was seen in only 3 of 18 MTX-treated patients, compared with 31 of 54 RA patients who were not receiving long-acting drugs. Total IgM production by unstimulated cultured mononuclear cells, pokeweed mitogen-induced antibody synthesis, and plasma levels of IgM-RF were also lower in MTX-treated patients than in other RA patients. The numbers of circulating B cells, T4 and T8 cells, the T4:T8 cell ratio, and mitogen-induced proliferation indices were similar in MTX-treated and non-MTX-treated patients. Eleven additional patients were studied prospectively after initiation of MTX therapy. All showed significant decreases in spontaneous IgM-RF synthesis, with declining IgM-RF:IgM ratios, including all of the 9 who were studied during the first 24 hours of treatment. The results indicate that MTX has rapid effects on IgM-RF synthesis, and this action might be associated with its therapeutic efficacy in RA.
mesh_terms: D001172:Arthritis, Rheumatoid / Q000188:drug therapy / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000096:biosynthesis; D008727:Methotrexate / Q000627:therapeutic use*; D009000:Monocytes / Q000276:immunology; D012217:Rheumatoid Factor / Q000096:biosynthesis
chemical_list: D007075:Immunoglobulin M; D012217:Rheumatoid Factor; D008727:Methotrexate