Cytokine production by blood mononuclear cells from in-patients with anorexia nervosa

Although protein-energy malnutrition is a common cause of immunodeficiency, the immune function in underweight anorexia nervosa (AN) patients usually seems to be better preserved than would be expected. However, a deranged cytokine production and its consequences are currently being investigated in these patients. This study was aimed at measuring, over time, the capacity of peripheral blood mononuclear cells (PBMC) from AN in-patients to produce several cytokines involved in the regulation of immune responses. The in vitro production of interferon (IFN)-gamma, interleukin (IL)-2, tumour necrosis factor (TNF)-alpha, IL-6 and IL-1 beta by phytohaemagglutinin-stimulated PBMC were assessed on forty female adolescents with AN. These measures were carried out twice, upon hospital admission and at discharge, which occurred on average after 1 month. Thirty-five control subjects were also studied. Cytokines were measured by ELISA kits. The production of TNF-alpha and IL-6 was lower and production of IL-1 beta higher in AN patients than in the control group at both time points of assessment. Refeeding for 1 month was not enough time to reverse these differences and patients still had a low body weight at discharge. IFN-gamma production was lower in the patients than in control subjects only at discharge and no differences were found in IL-2 production between both groups. The results suggest that a mechanism involving modifications in the secretion pattern of proinflammatory cytokines could explain some immune function findings in underweight AN patients.