A rapid radioimmunoassay for determination of dehydroepiandrosterone sulphate in human plasma.

A rapid radioimmunoassay for the determination of dehydroepiandrosterone sulphate (DHEA-S) in diluted human plasma is described. The radioimmunoassay is performed using an antiserum to DHEA-3-hemisuccinate-BSA. A charcoal-dextran mixture is used for separation of the bound from the free fraction. The reliability criteria of the method in terms of precision, accuracy, sensitivity and specificity have been evaluated. The mean level of DHEA-S in plasma samples from normal men (age range 24-37) is 241-5+/-72-5 mug/dl. In normal premenopausal women the highest values are in the second third of the menstrual cycle (corresponding to the ovulatory phase). In normal old men (age range 64-86) and in post-menopausal women (age range 55-88) the mean values are, respectively, 51-9+/-33-8 and 53-8+/-34-0. The DHEA-S levels found in several cases of adreno-cortical disorders are reported. In primary adrenal insufficiency and in Cushing's syndrome due to adrenal adenoma or bilateral multinodular hyperplasia low values are found; in Cushing's syndrome due to bilateral adrenal hyperplasia normal values are usually found.