Antibody to 1-24 ACTH and Hypofunction of the Adrenal Cortex in a Patient who was Unilaterally Adrenalectomized for Cushing's Syndrome

Abstract

We report here on a patient who was unilaterally adrenalectomized for Cushing's syndrome, and who developed antibodies to 1-24 ACTH. A 49-year-old nurse had undergone right adrenalectomy for adrenal adenoma. After surgery, she was treated with 0.5 mg of 1-24 ACTH-Z together with glucocorticoid replacement therapy for 40 days. Thereafter she was given 0.25-0.5 mg of ACTH-Z every other day for 4 months. ACTH-Z was then stopped for a year but glucocorticoid therapy was continued. About one year prior to this admission, 1 mg of ACTH-Z was again initiated 1 to 2 times a week. Glucocorticoid therapy was not withdrawn during the four years after adrenalectomy. She was admitted for the purpose of withdrawal of glucocorticoids. Her serum was found to bind labeled ACTH. This labeled ACTH was competitively displaced from binding by unlabeled hormones. Finally, reaction with specific antihuman Ig demonstrated an antibody of the IgG class. The titer of the antibodies gradually decreased after the discontinuation of ACTH-Z, but it is still present in measurable quantity in her serum. The clinical significance of the circulating anti-ACTH antibody in her serum is discussed.