Interferon production of vitro by leucocytes from patients with systemic lupus erythematosus and rheumatoid arthritis.

The production of interferons (IFN) by peripheral blood leucocytes from normal donors an patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) has been investigated in response to several IFN inducers in vitro. Whereas IFN responses of RA donors did not differ significantly from the normal group, those of SLE patients were significantly reduced, and many of these patients failed to respond to all. Patients with active or acute SLE responded significantly less well than those with inactive disease. There was no apparent effect of steroid therapy on the IFN responses of either SLE or RA patients. These data may indicate a basic immunological defect of the circulating leucocytes of SLE patients, which may be responsible for some of the in vitro lymphocyte anomalies reported for this disease.