Lymphocyte populations in rheumatoid arthritis

Abstract
For each of 28 patients with RA and 27 normal controls, the in vitro lymphocyte responses to PHA and to Con A were simultaneously determined on aliquots of the same cell preparation. In the case of RA lymphocytes, the response to Con A was abnormally low when compared with the simultaneous response to PHA (P < 0.01). Cells capable of responding to PHA were specifically killed with BUdR. The cells remaining after this procedure showed a relatively greater response to Con A than did the original population. In the case of RA lymphocytes, this relative increase in the response to Con A was significantly less than normal (0.02 > P > 0.01). These results suggest that a lymphocyte subpopulation, responding principally to Con A, is relatively reduced in RA.