Immunosuppressive effects of glucocorticosteroids: differential effects of acute vs chronic administration on...

The effects of acute vs. chronic glucocorticosteroid administration on established cellular immune responses were studied in guinea pigs previously sensitized to tuberculin. A greater than 50% reduction in circulating lymphocytes was observed 4 hr after injection of soluble hydrocortisone and 24 hr after daily subcutaneous injections of depot cortisone acetate. After a single dose of hydrocortisone, peripheral lymphocyte migration inhibitory factor (MIF) production and antigen and mitogen-induced proliferation were unchanged. However, the peripheral lymphocytes remaining in the circulation after chronic cortisone treatment showed a marked decrease in both antigen-induced MIF and proliferation, although mitogen responses remained normal. Although similar levels of lymphocytopenia were induced by acute and chronic glucocorticosteroid administration, only chronic treatment was associated with depression of certain cell-mediated lymphocyte functions. The available evidence suggests that these changes may depend on GCS-induced selective alterations in the circulation patterns of certain subpopulations of lymphocytes.