The metabolism of IgE in patients with immunodeficiency states and neoplastic conditions.

Serum IgE concentrations were determined and IgE turnover studies were performed in control individuals as well as in patients with several disease states. Patients with common variable hypogammaglobulinemia, thymoma and hypogammaglobulinemia, ataxia telangiectasia, and selective IgA deficiency had significantly decreased mean serum IgE concentrations. In turnover studies, this was found to be due to decreased IgE synthesis. In spite of these depressed mean values, some patients with common variable hypogammaglobulinemia had normal serum IgE concentrations and synthetic rates. Patients with the Wiskott-Aldrich syndrome had a significantly elevated mean serum IgE concentration. In one of four patients studied with the turnover technique, a strikingly high IgE concentration was present and was associated with an elevated IgE synthetic rate. Three other patients had both normal serum IgE concentrations and synthetic rates. Patients with chronic lymphocytic leukemia had significantly decreased mean serum concentrations and synthetic rates for IgE. The depressed IgE synthesis was associated with a significantly prolonged IgE half-life. Patients with Hodgkin's disease had significantly increased serum IgE concentrations. One of three patients studied had a high serum IgE concentration and synthetic rate of IgE. The two other patients had normal serum IgE concentrations associated with normal synthetic rates. Finally patients with protein-losing enteropathy or familial hypercatabolic hypoproteinemia had normal IgE concentrations associated with normal IgE metabolic parameters. In these cases, the disorder in the catabolic rate was not severe enough to affect the total amount of circulating IgE because IgE normally has a very high fractional catabolic rate. In general, IgE levels in a variety of disease states were correlated with IgE synthetic rates and abnormalities in the catabolic rate of IgE in disease did not exert an important effect on IgE concentration.