Large molecular weight ACTH immunoactivity in a patient with adrenoleukomyeloneuropathy

Very high ACTH immunoactivity was measured in a patient with adrenoleukomyeloneuropathy. The basal adrenocortical function was hyperactive, whereas the response to exogenous ACTH was depressed. Most of the ACTH immunoactivity was a large molecule (55,000 daltons), which weakly stimulated steroidogenesis of adrenocortical cells in vitro, but inhibited the binding of 125I-iodoACTH to the cells and suppressed ACTH-induced steroid production. Abnormalities in the pituitary-adrenal axis in adrenoleukomyeloneuropathy have been considered to be solely attributable to destruction of the adrenal cortex. In the current case, however, large molecular weight ACTH immunoactivity is present and might have some role in the adrenocortical dysfunction.