Mitogen stimulation of whole blood microcultures from patients with rheumatic disease.

In this study the lymphocyte function of therapy matched rheumatoid and non-rheumatoid patients in the mitogen mediated in vitro whole blood microculture system has been analyzed. Normal responses to phytohemagglutinin (PHA) and poke weed mitogen (PWM) and depressed responses to concanavalin A (Con A) were found. The PHA and Con A responses were influenced by drug therapy. Differences in the relative activity of PHA to Con A among the groups studied further supports the contention that rheumatoid arthritis (RA) patients have functional abnormalities in their T cell subpopulations. These differences were not due to a decrease in circulating lymphocytes or in the ratio of T lymphocyte numbers but likely reflects a disproportionate representation of Con A reactive T cells in the circulating T cell pool of RA patients.