Pituitary-adrenal-immune system in normal subjects and in patients with anorexia nervosa: the number of circulating helper T lymphocytes (CD4) expressing the homing receptor Leu8 is regulated in part by pituitary-adrenal products

The association between plasma pituitary-adrenal (PA) hormones and the number of certain populations of peripheral blood lymphocytes (PBL) was examined in subjects with normal PA function and in patients with anorexia nervosa (AN). AN patients display several neuroendocrine dysfunctions, including hypercortisolemia. In the normal subjects there were positive correlations between adrenocorticotropic hormone (ACTH) and the number of PBL and helper T lymphocytes expressing the homing receptor Leu8 (CD4+Leu8+); there was a negative relationship between cortisol and these lymphocyte populations. These latter, inverse correlations did not occur in the AN patients, either while underweight or after weight recovery, with some persistence of hypercortisolemia. Administration of dexamethasone (DEX) suppressed cortisol levels and reduced, perhaps via a receptor-mediated mechanism, the number of circulating PBL and CD4+Leu8+ in the normal subjects but not in the AN patients. These results support the physiological relevance of PA-CMI interaction in subjects with normal PA function and indicate that the PA-CMI interrelationship is disrupted in AN patients with hypercortisolemia.