[An immunohistochemical study on cellular infiltration of bronchial walls in bronchial asthma]

Inflammatory cell reactions in bronchial asthma have been considered to contribute directly to asthmatic attacks. Therefore, attention has been focused on the role of inflammatory cells in the airway wall. In this study, we investigated inflammatory cells in the airway wall of bronchial asthma histologically and immunohistologically using 20 autopsy cases who died of the asthma attacks (Group A) and 11 autopsy cases who died of other causes (Group B). Six autopsy cases were treated as controls (Group C). A significantly larger number of eosinophils in the bronchi and bronchioles were found in Group A. The majority of eosinophils were found to be stained with EG2. Parts of the bronchial epithelium with marked infiltration of EG2 positive eosinophils were detached from the basal layer. Immunoelectron microscopically, the matrix of EG2 positive areas within the eosinophils corresponded to that of eosinophil granules. A significantly larger number of lymphocytes in the bronchi and bronchioles was observed in Groups A and B. Almost all of these lymphocytes were determined to be activated T lymphocytes. There were significantly more IgE positive cells in cases with bronchial asthma, especially in Group A. The majority of IgE positive cells were determined to be mast cells. These results suggest that eosinophils, lymphocytes and mast cells play an important role in the pathogenesis of bronchial asthma.