Expression of the addisonian autoantigen in human adrenal tumors

Sera of patients with Addison's disease contain autoantibodies recognizing antigen(s) in the adrenal cortex. In the present study we have examined the antigen expression in normal (n = 6) and pathological human adrenal tissues (n = 24) and also in the human steroid-producing adrenocortical cell line NCI-H295. Sera from two patients with Addison's disease were selected as they strongly stained the human adrenal gland and identified a 54 kDa autoantigen previously demonstrated as 21-hydroxylase. These sera reacted with normal human adrenal cortex (n = 6), all hyperplasias (n = 5) and all the adrenocortical cancers (n = 9), whereas slight or no reactivity was observed in the adenomas without any detectable excess of peripheral steroids (n = 4). Both patient sera reacted in an identical manner with each tissue specimen and they also reacted strongly with the steroid-producing cell line. The data demonstrate that the expression of the Addisonian autoantigen correlates with the functional activity of adrenocortical neoplasms. Furthermore they suggest, that immunohistochemical stainings for steroid-producing enzymes may be clinically useful in the characterization of adrenal lesions.