T lymphocyte subpopulations in rheumatoid arthritis.

The number of various lymphocyte subpopulations in the peripheral blood of 28 patients with definite rheumatoid arthritis (RA) were studied. The results were correlated with the disease activity, as assessed by the Ritchie index, erythrocyte sedimentation rate and clinical impression. Patients with active RA showed decreased numbers of T mu lymphocytes, strongly increased numbers of Tnull lymphocytes and slightly increased percentages of Fc gamma lymphocytes as compared to 22 healthy donors. Patients with inactive RA had similar, less striking, but significant changes in T mu and Tnull lymphocytes, but in contrast to patients with active RA had Increased numbers of T gamma lymphocytes. The imbalances in T mu and Tnull cells in patients with RA might be explained by endogenous T mu cell activation, resulting in increased numbers of Tnull cells.