Altered reactivity in mixed lymphocyte culture of lymphocytes from patients with rheumatoid arthritis

Abstract Lymphocytes from patients with rheumatoid arthritis were studied in one‐way stimulation mixed leukocyte culture (MLC) and results compared with cultured pairs of rheumatoid and normal lymphocytes. In 14 of 22 experiments, no lymphocyte stimulation was noted when rheumatoid arthritis lymphocytes obtained from unrelated patients were studied in MLC. Normal lymphocytes produced stimulation of rheumatoid cells in 16 of 22 instances, and rheumatoid lymphocytes induced transformation of normal subjects' lymphocytes in 19 of 22 experiments. Marked alteration in mutual lymphocyte stimulation was thus recorded when cells from some patients with rheumatoid arthritis were studied together.