The role of IgE in atopic diseases

The fact that about 20% of the patients with severe atopic disease have normal or subnormal serum IgE levels, and that the severity of the disease does not always correlate with IgE levels, does not reduce the importance of this antibody in the onset of the illness. A possibility is suggested here that even low IgE concentrations are capable of playing a key role in the pathogenesis of the disease, and being directly responsible for its clinical manifestations. Namely, atopic patients who show low IgE levels seem to have high tissue sensitivity even to these low levels of IgE and to react with these low concentrations of the antibody.