Stimulation of lymphocyte transformation by autologous serum fractions from patients with rheumatoid arthritis.

lymphocyte transformation was used in an attempt to demonstrate hypersensitivity reaction to gamma-globulin in patients with rheumatoid arthritis. Peripheral blood lymphocytes from Latex-positive rheumatoid patients were cultured in TC 199 fluid for 3 days in the presence of autologous gamma-globulin preparations (concentrations of 0.01–11 mg/ml), and the percentage blast formation determined microscopically on 1000 cells. Negative controls and phytohaemagglutinin controls were included. Transformation of 10 per cent or more was considered significant. Whole gamma-globulin obtained by ammonium sulphate precipitation failed to stimulate autologous lymphocyte transformation. IgM and IgG fractions obtained by gel filtration on Sephadex G-200 at pH 4.05 stimulated transformation in five out of ten and eight out of ten autologous lymphocyte cultures. The activities of the IgM and IgG fractions could be distinguished by their specificities (homo- and auto-specificity, respectively). Controls including IgM and IgG fractions from healthy persons, Latex-negative rheumatoids, and patients with other connective tissue diseases in autologous culture and IgG from rheumatoids in homologous culture failed to stimulate transformation. Further fractionation of blasto-genically active IgG fractions on DEAE—cellulose and on goat antihuman IgG coupled to Sepharose, in order to determine if the activity was associated with IgG, was unsuccessful, since most of the activity was lost during the procedures.