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 [T(M), T(G) and EA(hu) 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 T(M) (38 ± 2.4 before; 22 ± 2.9 after; P < 0.0005) and T4 (48 ± 2.6 before; 35.8 ± 2.7 after; P < 0.0025) lymphocytes. Transplanted patients under chronic immunosuppression already disclosed a reduction of the percentages of T(M) (19.4 ± 2.6; P < 0.005) and T4 (41.1 ± 3.6; P < 0.05) lymphocytes before the administration of hydrocortisone when compared to the values obtained in normals. Moreover, significant decrease of percentages of T(M) lymphocytes (19.4 ± 2.6 before; 12.8 ± 2.6 after; P < 0.01) were obtained after hydrocortisone injection. In contrast, T8, T(G) and EA(hu) rosettes percentages were characterized by a relative resistance to immunosuppressive agents - the only exception being T(G) lymphocytes in transplant recipients. It is concluded that T(M) 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.SCOPUS: ar.j