Autoimmune Adrenal Insufficiency

Abstract

The main cause of Addison’s disease is an autoimmune organ-specific destruction of the cells in the adrenal cortex by an autoreactive process of activated immune cells directed against the steroid-synthesising enzyme 21-hydroxylase. The diagnosis of Addison’s disease is suspected in a patient presenting with symptoms of fatigue, bodyweight loss, anorexia, salt craving, and signs of low blood pressure and hyperpigmentation of the skin. Laboratory findings include electrolyte disturbances, and typically an elevated serum potassium level and sometimes a low serum sodium level is found together with low plasma levels of basal and corticotropin-stimulated hydrocortisone (cortisol). An aetiological diagnosis can rapidly be made using commercially available assays demonstrating the presence of autoantibodies directed against 21-hydroxylase. Determination of 21-hydroxylase autoantibodies also permits early diagnosis before a complete adrenocortical destruction has occurred. Thus, a window of opportunity for an early immunomodulatory intervention therapy may exist. Patients presenting with an acute adrenocortical crisis should be treated with 100mg of hydrocortisone and saline intravenously without awaiting laboratory results. Maintenance therapy includes substitution of glucocorticoid and mineralocorticoid steroids, using divided and lower total dosages of glucocorticoids than previously used.