Immunoglobulin synthesis by peripheral blood cells in systemic lupus erythematosus.

A study of the immunoglobulin (Ig) synthesis by peripheral blood cells of patients with systemic lupus erythematosus (SLE), rheumatoid arthritis, and controls was carried out. Synthesis was markedly elevated in patients with active SLE, whereas patients with the active SLE or RA showed normal values. Treatment of 3 patients with active SLE resulted in a reduction of Ig synthesis that correlated well with the disappearance of disease activity. There results indicate that the abnormal immune process in active SLE, characterized by intense B-lymphocyte stimulation, is associated with the appearance of more highly differentiated B cells in the blood.