Lymphocyte suppressor activity in atopic eczema

Abstract

Previous studies have shown that patients with atopic eczema have depressed cell-mediated immunity. Whether this defect can be attributed to abnormal suppressor cell activity or to the presence of mediators of the allergic response has not been studied before. Lymphocyte transformation was found to be enhanced in patients with mild eczema and markedly depressed in patients with severe eczema, when compared with normal controls. Pre-incubation of cultures for 48 hr without mitogen prior to transformation studies restored normal lymphocyte thymidine uptake in cells from severe atopics, suggesting a labile suppressor cell population, or a labile suppressor substance. Since mononuclear cell supernatants from patients with severe eczema failed to suppress lymphocyte transformation more than supernatants from normals, it is unlikely that the depressed lymphocyte function seen in severe eczema is due to an abnormal suppressor cell population. The possibility that mediators of the allergic response may be acting as a labile suppressor substance was evaluated by adding various concentrations of histamine, cyclic-AMP, or prostaglandin E₁ to lymphocytes undergoing mitogenesis. Histamine enhanced thymidine incorporation at low concentrations and depressed uptake at high concentrations; cyclic-AMP and prostaglandin E₁ have similar effects on transformation. It is possible that the enhancement of transformation seen in mild eczema and the depression of this response in severe eczema may be related to the concentrations or degree of allergic mediator release.