Serum IgE levels in healthy black American children: a case for environmental influences on IgE.

Serum IgE was determined in 115 healthy, non-atopic black American children, aged 0-16 years, living in Urban Chicago. The mean IgE level varied from 1.48 u/ml at birth to 70 u/ml at adolescence. These values are comparable to those observed in American whites but differ significantly from the IgE levels of both African blacks and European Caucasians. Thus, environmental factors apparently exert a strong influence on IgE production in non-atopic individual.