The detection of IgE-secreting cells in the peripheral blood of patients with atopic dermatitis

Abstract

We report, for the first time, the identification of IgE-secreting cells in human peripheral blood with an ELISA plaque assay that detects the fingerprint of individual IgE-secreting cells. No IgE-secreting cells could be detected in the blood of normal individuals (IgE, <100 IU/ml) or atopic patients (IgE, <1000 IU/ml), but in patients with atopic dermatitis (AD) whose IgE was >2000 IU/ ml, there was an average of 49 ± 9 IgE-secreting cells per 10 6 peripheral blood mononuclear cells (PBMNCs). The rate of IgE production per cell per day from the PBMNCs of patients with AD varied from 0.051 to 0.628 IU/ml, and the number of IgE-secreting cells was positively correlated with the serum-IgE levels of these subjects ( r = 0.74; p < 0.001) and the amount of IgE detected in the culture supernatant ( r = 0.085: p < 0.02). Secretion of IgE by these cells could be completely inhibited (96.2% ± 3%) by the addition of 75 μg of cyclohexamide to the cultures. Preformed intracellular IgE comprised 10% of the IgE detected in the supernatants of 7-day cultures. PBMNCs from patients with AD depleted of monocytes by adherence and T cells by E rosetting, all contained some detectable IgE-secreting cells, whereas isolated T cells and monocytes did not, supporting the view that cells secreting IgE that were detected were indeed B cells.