Basal serum IgE levels and HLA antigen frequencies in allergic subjects

In allergic Caucasian subjects, IgE-mediated responsiveness to the rye grass Group I (Rye I) antigen is significantly associated with possession of HLA-B8 (p = 0.001). Analysis of this association relative to basal total serum IgE level showed a marked relationship in Rye I-negative subjects, where the frequency of B8 was much higher at high than at low IgE levels. In Rye I-positive subjects, there was evidence for the converse situation. In the case of people sensitive to ragweed antigen E, we found no association with any HLA specificity, even in patients with low IgE levels. TheHLA-associated specific IgE responses to rye grass Group I, and those we have previously reported for ragweed Ra3 and Ra5, lead us to speculate about the possible locations within theHLA complex of putativeIr loci controlling recognition of these allergens. Further, we postulate the existence of twoI regions.I-1, which contains “Ir-Rye I” and“Ir-Ra5”, andI-2, which contains “Ir-Ra3”. Alternative explanations of our findings are also discussed in detail.