Cell-mediated immunity in anorexia nervosa augmented lymphocyte transformation response to concanavalin A and lack of increased risk of infection.

Cell-mediated immunity (CMI) was studied in 33 consecutively admitted patients with anorexia nervosa (AN) who had a mean weight loss of 30%. Clinical infections were not diagnosed in the patients. The acute phase reactant, C-reactive protein, was slightly elevated in only one patient, but was within the normal range in the remainder. The absolute number of T-lymphocytes in peripheral blood was significantly increased (p < 0.01) in the AN-patients compared to the control group while the number of granulocytes was reduced (p < 0.01). However, a significant negative correlation between the relative weight loss and the numbers of both total and T-lymphocytes in the AN-patients was established (p < 0.05). Mitogen stimulation of lymphocytes with phytohemagglutinin (PHA), poke-weed-mitogen (PWM) and concanavalin A (Con A) showed no reduction in the proliferative response in AN-patients compared to the control group. On the contrary, Con A transformation was significantly higher (p < 0.03) in the AN-patients. The lymphocyte response to PWM (p < 0.02) was, however, diminished in the patients with the most advanced weight loss compared to those with the least weight loss.