Lymphokine production in rheumatoid arthritis and systemic lupus erythematosus.

The production of interferon (IFN) by peripheral blood lymphocytes from patients with rheumatoid arthritis (RA) and of IFN and interleukin 2 (IL-2) in systemic lupus erythematosus (SLE) was compared with that of healthy controls. Patients with SLE showed a significant reduction in IL-2 production compared to controls if the PBL were irradiated before mitogen stimulation. No patient with RA or SLE studied had impaired IFN production regardless of disease activity and the IFN produced was always IFN-gamma in type. We conclude that there is an abnormality in IL-2 production in SLE but there is no abnormality in IFN-gamma production in either RA or SLE.