In vitro stimulation of lymphocytes from patients with rheumatoid arthritis

Peripheral blood lymphocytes from patients with rheumatoid arthritis (RA) and from normal controls were compared in 20 microliters droplet cultures following stimulation with phytohemagglutinin or concanavalin A. The dynamics of proliferation were significantly changed in RA. Higher numbers of cells in culture were needed to achieve the same response. This may explain the low proliferative responses of lymphocytes from some patients with RA, and apparent changes of in vitro suppressor effects, reported by other authors. Diurnal variations of lymphocytes in RA patients were also studied. No differences in the response to mitogen of lymphocytes taken at 7 AM and 7 PM were found.