The effect of cyclosporin A on peripheral blood T cell subpopulations in renal allografts.

Treatment with cyclosporin A (CyA) produces a reversal of the normal ratio of OKT4+ (inducer type) to OKT84 (suppressor-cytotoxic type) cells so that renal allograft recipients on CyA alone develop a four-fold increase in the absolute number of circulating OKT8 positive cells. Conventional immunosuppression with azathioprine and prednisolone reduces both populations of T cells without altering the ratio of OKT4+ to OKT8+ cells. This effect of CyA may help to explain its action as an immunosuppressive agent.