EFFECT OF REGULAR INHALED ALBUTEROL ON ALLERGEN-INDUCED LATE RESPONSES AND SPUTUM EOSINOPHILS IN ASTHMATIC SUBJECTS

Treatment with inhaled beta(2)-agonists immediately before allergen in halation inhibits allergen-induced early, but not late asthmatic respo nses (LAR). By contrast, 2 wk treatment with inhaled albuterol increas es airway responses to inhaled allergen. We examined the effects of re gular albuterol treatment on allergen-induced increases in inflammator y cells in blood and induced sputum. Ten mild, stable allergic asthmat ics inhaled albuterol (800 mu g/day) or placebo for 7 d in a controlle d, randomized, double-blind, crossover study. Allergen inhalation was performed 12 h after the final dose. Methacholine airway responsivenes s and blood samples were analyzed before and 24 h after, and induced s putum was obtained before, 7 h and 24 h after allergen. Allergen signi ficantly reduced methacholine PC20, increased blood eosinophil numbers , and numbers of sputum neutrophils, EG2 positive and metachromatic ce lls (p < 0.05), without significant differences between treatments. Al buterol treatment significantly increased the LAR compared to placebo treatment (p = 0.003) and significantly enhanced the number of sputum eosinophils (p = 0.009) and sputum ECP (p = 0.04) at 7 h but not 24 h post-allergen (p > 0.05). We conclude that regular use of inhaled albu terol significantly increases the LAR to inhaled allergen, in associat ion with an increase in the number of sputum eosinophils and the relea se of ECP, suggesting albuterol increases the late response by increas ing eosinophil influx into the airways.