Endobronchial allergen challenge

Abstract

LEAC offers a very practical means of studying the pathophysiology of asthma. Despite the local nature of the challenge, LEAC often has a significant effect on FEV1 and may cause short-term destabilization of asthma. In common with other bronchoscopic methods used to study human asthma, samples obtained by LEAC show a considerable degree of variability and it is therefore necessary to use groups of 12-15 subjects to minimize the risk of Type II statistical errors. Comparisons between different studies of allergen exposure are made difficult by a variety of technical considerations. Chief among these are subject selection, the technique used for allergen exposure, the timing of sampling, and the analysis techniques. Dose-response studies in nonasthmatic allergic subjects indicate that the degree of BAL eosinophilia is related to the dose of antigen [17] but there is as yet no agreement on how LEAC might be standardized. Notwithstanding these reservations, local endobronchial allergen challenge has already yielded valuable information on the pathophysiology of asthma and will remain a useful complement to other investigational techniques in the future exploration of this disease.