The effect of acute and prolonged administration of prednisolone and ACTH on lymphocyte subpopulations.

The effect of acute and prolonged three week administration of prednisolone and ACTH on the numbers and function of T- and B-lymphocyte subpopulations in patients requiring corticosteroid therapy was studied. Prednisolone caused severe reduction in E-rosette-forming lymphocytes, phytohaemagglutinin response, EAC-rosette-forming lymphocytes and surface-membrane mu-positive B-lymphocytes maximal at 4--6 hr after administration with reversal sometimes to supernormal levels by 24 hr. Prolonged administration resulted in a similar pattern of response. Acute but not prolonged prednisolone administration caused a reduction in the percentage of E-rosette-forming lymphocytes maximal at 4 hr. ACTH caused moderate reduction in these parameters at 4 and 6 hr which remained low at 24 hr after prolonged administration.