Pituitary-adrenal responses to corticotropin-releasing factor in late onset 21-hydroxylase deficiency.

Intravenous corticotropin-releasing factor (CRF) and adrenocorticotropin hormone (ACTH) were administered in patients with adult onset 21-hydroxylase deficiency to compare their diagnostic capability as well as to investigate hypothalamic-pituitary-adrenal function in this disorder. Responses of 17-hydroxyprogesterone, which were markedly elevated compared with controls, were identical with CRF and ACTH. However, intravenous ACTH resulted in higher androstenedione levels in comparison to CRF. Adrenocorticotropin hormone also resulted in decreased cortisol responses, confirming a defect in steroidogenesis, a finding that was not evident with CRF. Plasma ACTH responses to CRF were similar in patients and controls. We conclude that CRF may be as useful as ACTH as a diagnostic test for adult onset 21-hydroxylase deficiency, and that because normal levels of plasma ACTH were evoked by CRF in 21-hydroxylase deficiency, lower doses of exogenous ACTH may be sufficient for making this diagnosis. Although no obvious hypothalamic-pituitary dysfunction could be demonstrated in our patients with 21-hydroxylase deficiency by using CRF, our data confirm the adrenal sensitivity of patients with adult onset 21-hydroxylase deficiency.