LAUSR

Isolated adrenocorticotropic hormone (ACTH) deficiency (IAD) is a rare pituitary disorder characterized by decreased secretion of ACTH, leading to cortisol deficiency, with normal secretion of other pituitary hormones. Diagnostics remains a challenge due to variable and nonspecific clinical presentation: weakness, weight loss, and low blood pressure. Hyponatremia and anemia are typical abnormalities in basic laboratory tests. Diagnostic procedures for IAD are based on results of low morning cortisol with low/normal ACTH concentrations, with flat response of these hormones in dynamic tests [with insulin/glucagon/corticotropin-releasing hormone (CRH)]. There is also no cortisol response to Synacthen during the standard (not extended) test duration. Several aetiologies lead to the development of IAD. The congenital form is typical of childhood onset. In adults, autoimmune aetiology prevails, including lymphocytic hypophysitis, and rarer - pituitary injury or other lesions in the gland. IAD has recently been demonstrated as a complication in patients receiving therapy with immune checkpoint inhibitors. Also, in the case of IAD, paraneoplastic autoimmune hypophysitis should be considered. Next, alcohol abuse has been reported to be a reason of IAD in single cases. Treatment with oral hydrocortisone usually causes significant improvement. As an example, we present 2 patients diagnosed with IAD. Both were older males, with history of alcohol abuse, long lasting hyponatremia, and weakness. Their clinical state normalized after receiving replacement therapy with hydrocortisone.