Formation of IgE-binding factors by lymphocytes of HIV-infected patients

Peripheral blood mononuclear cells of human immunodeficiency virus infected patients were cultured in the presence or absence of 10 μg/ml human IgE, and culture filtrates were fractionated on IgE-Sepharose. IgE-binding factors were assessed in the acid eluate fraction from IgE-Sepharose by both rosette inhibition assay and radioimmunoassay. Among 22 cases studied, mononuclear cells from 9 patients formed IgE-binding factors in the absence of IgE, and those of 13 cases formed the factors upon incubation with IgE. The major cell source of IgE-binding factors was T cells. In 2 cases of human immunodeficiency virus infection, Fc(ε) receptors were detected on both Leu-2⁺ and Leu-3⁺ T cells.