Reduced production of interferon alpha and interferon gamma in leukocyte cultures from patients with active...

Tests for lymphoproliferation and interferon induction in normal blood donors and patients with rheumatoid arthritis (RA) were performed in a whole-blood assay. Patients with high inflammatory RA showed significantly reduced lymphoproliferation and interferon gamma production after stimulation with phytohemagglutinin (PHA) and concanavalin A (Con A) when compared with patients with low inflammatory activity, or with normal control individuals. Similarly, patients with high and low inflammatory RA exhibited a significantly reduced interferon alpha production after stimulation with Newcastle Disease Virus (NDV) when compared with normal blood donors. Our findings may point to an important immunodeficiency of the circulating lymphocytes of RA patients and may explain some of the in vitro immunoregulatory abnormalities reported in this disease.