PPD AND MITOGEN RESPONSIVENESS OF LYMPHOCYTES FROM PATIENTS WITH ATOPIC-DERMATITIS

Abstract

Lymphocytes from 25 patients with atopic dermatitis were investigated for their in vitro reactivity to stimulation with tuberculin (PPD), [Escherichia coli] lipopolysaccharide (LPS), phytohemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM). The response to a low dose of Con A was increased, and the reactivity in unstimulated cultures tended to be lower than similar cultures from the control group. Addition of inactivated autologous plasma to the cultures had an inhibitory effect when the plasma came from patients with high levels of IgE [immunoglobulin E]. The patients'' in vitro reactivity to PPD in a leukocyte migration test was equal to that found in normal persons, and no effect was observed after addition of autologous serum. The mean percentage of E [erythrocyte] rosette forming cells was significantly reduced in patients with high levels of IgE. The number of EAC [E, antibody, complement complex] rosette forming cells was within normal range. The observations could reflect the existence of suppressor mechanisms in patients in which the immune system is strongly stimulated.