Studies of HLA antigen frequencies, IgE levels, and specific allergic sensitivities in patients having ragweed hayfever, with and without asthma.

In order to study genetic and immunological features which might be important in the pathogenesis of asthma, forty-one ragweed allergic seasonal asthmatics were first matched with forty-one ragweed allergic nonasthmatics on the basis of similar total IgE levels. No significant differences were observed in their sensitivity to ragweed antigen E (measured by histamine release), or in their skin response to ragweed antigens E, Ra3 and Ra5. An increased frequency of HLA-B5 was observed in nonasthmatics as compared to asthmatics (P = 0-03). Although frequencies of HLA-A1 and B8 were also elevated in nonasthmatics and HLA-B40 in asthmatics, these differences were not significant. The forty-one asthmatic patients were than paired with forty-one nonasthmatics patients were then paired with forty-one nonasthmatics on the basis of leucocyte sensitivity to ragweed antigen E. Similar HLA differences were found which were non-significant. No significant difference in total IgE levels were found between the two groups. Whereas no differences in IgE synthesis or antigen sensitivity was found in the two populations, the frequency of HLA antigens needs further study in larger groups.