Nonspecific suppressor function in rheumatoid arthritis.

Patients with rheumatoid arthritis (RA) have diminished peripheral blood cellular immune responses in vivo and in vitro. To determine whether these changes reflected excessive peripheral blood suppressor function, we compared suppressor function in 52 patients with RA with 57 normal subjects. We examined suppressor cell function for (i) preincubation sensitivity, (ii) glass adherence, (iii) indomethacin sensitivity, (iv) concanavalin (con) A inducibility, (v) aggregated IgG inducibility and (vi) quantitated Tmu and Tgamma cell populations. Con A-generated suppressor cell function was further studied by evaluating unseparated-, T-cell, glass adherent-, indomethacin sensitive-, radiosensitive-, and radioresistant-suppressor cell effects upon mitogen-stimulated allogeneic and autologous unseparated, T-cell, B-cell and IM9 lymphoblastoid cell line responses, the latter representing a newly devised and simplified assay system. We found that patients with RA exhibited: (i) significantly increased incubation-sensitive suppressor function; (ii) generally normal nonspecific suppression function in other assays, although individual patients were strikingly abnormal; and (iii) significantly increased sensitivity of B-cell proliferation to aggregated-IgG-induced T-cell suppressor function.