Immunoallergological studies were carried out to clarify the differences between 24 patients with drug-induced asthma (DIA) and 240 with non-drug-induced asthma (non-DIA). The mean values of age, skin reaction to Candida albicans (C. albicans), serum IgE levels, specific IgE antibodies to house dust (HD) and C. albicans, bronchial sensitivity and leukotriene B4 (LTB4) synthesis from peripheral venous blood in patients with DIA were not significantly different from those in patients with non-DIA. In contrast, the frequency of positive skin reaction to HD and histamine release from peripheral basophils by anti-IgE were significantly lower in DIA than in non-DIA. These results agree with the reports that DIA was often observed in non-atopic asthma. But, the mean value of serum IgE was very high in DIA as well as in non-DIA. This result suggests that IgE mediated reaction in DIA is important. Furthermore, the proportion of neutrophils in bronchoalveolar lavage fluid (BALF) was significantly lower in DIA than in non-DIA. Our findings suggest that a decrease of intrapulmonary neutrophils might play an important role in the pathophysiology of DIA.</p
