Depletion of lymphocytes with membrane markers of helper phenotype: a feature of acute and chronic drug-induced immunosuppression.

T cell subsets tested with markers for Fc receptors for Ig (TM, TG and EAhu rosettes) or monoclonal antibodies (T4 and T8 lymphocytes) were investigated both in normal volunteers and in kidney transplant recipients with a well functioning graft and receiving low immunosuppressive therapy, before and 4 hr after administration of 100 mg of hydrocortisone. Hydrocortisone induced a redistribution which was characterized by a decrease in the percentages of TM (38 +/- 2.4 before; 22 +/- 2.9 after; P less than 0.0005) and T4 (48 +/- 2.6 before; 35.8 +/- 2.7 after; P less than 0.0025) lymphocytes. Transplanted patients under chronic immunosuppression already disclosed a reduction of the percentages of TM (19.4 +/- 2.6; P less than 0.005) and T4 (41.1 +/- 3.6; P less than 0.05) lymphocytes before the administration of hydrocortisone when compared to the values obtained in normals. Moreover, significant decrease of percentages of TM lymphocytes (19.4 +/- 2.6 before; 12.8 +/- 2.6 after; P less than 0.01) were obtained after hydrocortisone injection. In contrast, T8, TG and EAhu rosettes percentages were characterized by a relative resistance to immunosuppressive agents--the only exception being TG lymphocytes in transplant recipients. It is concluded that TM and T4 depletion is a common feature of acute and chronic drug-induced immunosuppression, suggesting that helper-inducer cells are important targets for immunosuppressive therapy.