Lymphocytes with Immunoglobulin E Fc Receptors in Patients with Atopic Disorders

Abstract

Lymphocytes from normal nonallergic donors and patients with atopic disorders were analyzed for subpopulations bearing Fc receptors for immunoglobulin (Ig)E (Fc_ε) and IgG (Fc_γ), surface IgM (sIgM) and IgD (sIgD), and for T cells forming spontaneous rosettes with sheep erythrocytes (E). The patients were divided into three groups according to serum IgE concentrations and systemic corticosteroid treatment. Group I consisted of 12 atopic patients with either normal or moderately increased IgE levels up to 4,000 U/ml. Four patients of group II and three of group III had 10,500-31,000 U/ml and severe atopic dermatitis. Patients of group III, but not I and II, were receiving corticosteroids systemically. The percentage (mean ±SD) and total number of Fc_ε⁺ lymphocytes were 1.2±0.5%, 41±24/mm³ in 12 normals; 1.6±0.9%, 59±43/mm³ in patients of group I: 7.0±2.0%, 187±67/mm³ in group II; and 0.3±0.1%, 13±5/mm³ in patients of group III. The increase in group II and decrease in group III of Fc_ε⁺ cells were statistically significantly different from the normal persons and patients of group I. In contrast, the patients did not differ significantly from the donors in sIgM⁺, sIgD⁺, Fc_γ⁺, and E⁺ cell populations. As shown by depletion of sIg⁺ cells in four patients with atopic disorders, the great majority of the Fc_ε⁺ lymphocytes were B cells. However, two patients with elevated Fc_ε⁺ cell numbers had small numbers of mixed E- and Fc_ε-rosetting cells, presumably T cells. Two patients of group II were examined during an acute herpes simplex infection. Both showed an ≅80% decrease of Fc_ε⁺ cells at that time. No apparent correlation between numbers of Fc_ε⁺ cells and IgE level existed in patients of group I. Injection of an IgE myeloma protein into two monkeys did not significantly change their percentages of Fc_ε⁺ lymphocytes. The data indicate that Fc_ε⁺ lymphocytes are increased in patients with markedly elevated serum IgE and severe atopic disease, suggesting that these cells may be involved in the regulation and(or) synthesis of IgE antibody formation.