[The changes in cell population and chemical mediators in BALF following local allergen challenge]

In eight subjects who showed dual asthmatic response (DAR) in bronchial provocation tests (BPT) with specific allergens, local allergen challenge (LAC) was conducted using a flexible bronchofiberscope. We examined the concentrations of histamine, leukotriene B4 and C4 (LTB4 and LTC4) and cell populations in bronchoalveolar lavage fluid (BALF) collected before LAC (control), during the immediate response phase (IR), and the late response phase (LR). Control BALF was collected from the left lingula (B4 or B5), and BALF in the IR or LR phase from the right middle lobe (B4 or B5). Each BAL was conducted with 50 ml of saline at 37 degrees C and repeated three times in succession. It was noted that histamine increased significantly (p less than 0.05) in IR-BALF from the control level. In addition, the concentrations of LTC4 and the numbers of eosinophils increased in IR-BALF. In LR-BALF, the numbers of eosinophils (p less than 0.01), and the concentrations of histamine (p less than 0.05), LTC4 (p less than 0.05) and LTB4 increased. From these results, it was suggested that infiltration of eosinophils and various chemical mediators in the bronchial mucosa play important roles in the development of late asthmatic response.