HLA-Dw2: a genetic marker for human immune response to short ragweed pollen allergen Ra5. I. Response resulting primarily from natural antigenic exposure.

Abstract

Ultra-pure short ragweed pollen allergen Ra5 (5000 MW) was used to investigate the relationship between HLA type and IgE and IgG antibody (Ab) responses to Ra5 in 2 groups of Caucasian subjects, totaling 447 people. Using highly sensitive radioimmunoassay procedures to measure serum IgE and IgG Ab, qualitative responses to Ra5 in both groups were strongly associated with HLA-Dw2 (P < 0.0001). For example, 95% of 38 people with IgE Ab vs. 22% of 139 ragweed-allergic persons having no detectable IgE Ab to Ra5 were Dw2+. Quantitative log [IgE Ab] and log[IgG Ab] responses to Ra5 were highly correlated with Dw2 (P = 10-5 to 10-14) in 4 separate multiple regression analyses, examining the relationship between HLA type (and other variables) and Ab levels in the 2 study groups. Further studies showed that the primary association of Ra5 response was with Dw2 rather than DR2 and that various combinations of A3, B7 and Dw2 were less strongly associated than Dw2 alone.