Cell-mediated immunity in rheumatic diseases. II. Mitogen responses in RA, SLE, and other illnesses: correlation with T- and B-lymphocyte populations.

Lymphocyte responses to phytohemagglutinin, concanavalin A, and pokeweed mitogen were tested in normal patients and in patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), scleroderma (PSS), other connective tissue disease, and other illnesses. The relationship of lymphocyte response to diagnosis, therapy, and T- and B-lymphocyte populations was analyzed. Additional studies included the determination of proliferative responses of various combinations of purified T and B lymphocytes cultured with plant mitogens. Lymphocytes from patients with RA and SLE incorporated significantly less thymidine in the presence of plant mitogens as compared to normal and comparably ill subjects. Treatment had no effect on mitogen response. Responses to all three mitogens correlated closely in patients with RA, SLE, or PSS; no correlation was noted between the response to mitogen of lymphocytes in culture and the number of T cells cultured.