Evidence for a positive correlation between serum cortisol levels and IL-1beta production by peripheral mononuclear cells in anorexia nervosa

A hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis has been r eported in anorexia nervosa (AN), together with some immunological abnormal ities, involving citokine - and particularly Tumor Necrosis-Factor-alpha (T NF-alpha) - production by polymorphonuclear cells. The ability of pro-infla mmatory cytokines to activate the HPA axis is well known; however, there ar e no data demonstrating an interdependence between immunological and endocr ine response in AN. To investigate the presence of a correlation between im mune response and pituitary-adrenal function, plasma ACTH and serum cortiso l concentrations were measured in 13 AN patients and in the same number of controls. TNF-alpha and interleukin (IL)-1 beta production by ex-vivo unsti mulated and LPS-stimulated peripheral mononuclear cells was also assessed. Circulating cortisol concentrations were higher (p<0.01) in AN (156.7+/-45. 1 mu g/l, mean+/-SD) than in controls (105.9+/-25.7 mu g/l). Unstimulated I L-1 beta release in supernatants of mononuclear cell cultures was slightly but not significantly higher in AN than in controls, while TNF-alpha releas e was similar in the two groups. A positive correlation was found between I L-1 beta concentrations in unstimulated culture supranatants and serum cort isol levels in AN (r=0.782, p=0.002), while in normal subjects there was a trend toward a negative correlation; a slight positive correlation, while n ot significant, between IL-1 beta and plasma ACTH, as well as between TNF-a lpha and serum cortisol was also found in AN. These data suggest that the n ormal relationship between pro-inflammatory cytokines release, particularly IL-1 beta, and cortisol secretion is deranged in AN. (C) 2000, Editrice Ku rtis.