Blood eosinophilia in bronchial asthma and its relationship to IgE-mediated reactions.

The correlation between blood eosinophilia and anti-IgE-mediated histamine release was investigated in 22 bronchial asthma patients with peripheral eosinophilia (over 8%). In the cases (Group A-1 and Group A-2) in which house dust was the specific antigen, significant histamine release from basophils was induced by anti-IgE and house dust. The result indicates a relationship between eosinophilia and the IgE-mediated mechanism of disease onset. In the cases (Group A-3) with RAST scores of 0+ and 1+ to house dust, the anti-IgE-induced histamine release varied from low to high percentages, and the participation of the IgE-mediated pathway was indicated in some cases. In the cases (Group B) with negative skin reactions, few patients had a family history of allergic disease. Their ages at onset were higher, and they demonstrated lower total IgE levels. These cases showed an extremely low percent of histamine release from basophils, which indicated the absence of a correlation between eosinophilia and IgE-mediated mechanisms.