ACTH antibodies in patients receiving depot porcine ACTH to hasten recovery from pituitary-adrenal suppression.

Six patients who had experienced prolonged steroid-induced pituitary-adrenal suppression were treated with 100 U of depot procine ACTH every 2 to 4 days for several months. Such treatment did not hasten the recovery of normal pituitary-adrenal function compared with the rate of recovery of a group of similarly suppressed patients who received no depot ACTH. Eight of nine patients who received prolonged courses of depot porcine ACTH developed antibodies to ACTH that cross-reacted with endogenous ACTH, binding it in the circulation in inactive form and retarding its removal from the circulation. The presence of such antibodies did not in itself grossly alter pituitary-adrenal interrelationships.