Circulating IgE levels in a normal human population.

Circulating IgE levels were measured in a non-selected normal population using a solid phase radioimmunoassay (Phadebas Radioimmunosorbenttest "RIST"). The population was divided according to age into 6 subpopulations. Both the main and the subpopulation showed multimodal distributions with 3 maxima of their IgE levels and not a Gaussian distribution. According to the maxima, the multimodal distribution was divided into 3 groups designated AA, Aa and aa. The IgE geometric mean in each group differs statistically significant (p less than 0.01). The proportions of individuals in each group agreed with the theoretical frequencies derived from the Hardy-Weinberg law and with frequencies for atopic (a) and non-atopic (A) alleles (0.152 and 0.846, respectively), as calculated from clinical studies by WIENER et al. (1). After exclusion of Aa and aa individuals from the population the distribution was shown to be normal. The IgE geometric mean in the "net" main population was found to be 33 U/ml. This value is slightly higher than those of recent studies on IgE levels. The mean level of IgE in the different age-groups did not vary significantly from that of the main population although a tendency for a decrease of IgE levels with increasing age was noticeable.