Serum levels of total IgE in non-allergic children. Influence of genetic and environmental factors.

The purpose of this study was to establish the range of total serum IgE in a healthy population lacking personal and family history of allergy, as well as the influence of genetic factors (family history of allergy), environmental factors (degree of air pollution), age, and sex on the serum IgE levels. Using a commercial enzyme immunoassay (Phadezym IgE Prist) the mean serum level of IgE was determined in 363 non-atopic children from 0 to 12 years of age. The geometric mean of serum IgE increased according to age, indicating a positive correlation between both. Higher mean values of serum IgE were found for children with a family history of allergy, than for children without (27.82 and 14.49 U/ml respectively). The percentage of variation due to age was about 94.5% in children with no family history of allergy. The mean value of serum IgE increased with the degree of air pollution in the living area (15.49 U/ml in non-polluted areas, 20.78 U/ml in very polluted areas). However, the influence of air pollution was smaller than the influence of family history on the mean values of serum IgE. The mean value of serum IgE was not modified by sex.