Effect of a single dose of salmeterol on the increase in airway eosinophils induced by allergen challenge in asthmatic subjects

摘要

BACKGROUND—The longacting β2 agonist salmeterol is very effective inpreventing asthmatic responses to specific stimuli, and this effect could theoretically be due to some anti-inflammatory property inaddition to bronchodilator property.
METHODS—The protectiveeffect of a single dose of salmeterol (50 µg) on allergen inducedearly and late responses and on the associated airway inflammation wasinvestigated in a double blind, placebo controlled, crossover study in11 atopic asthmatic subjects. Eosinophil percentages and concentrationsof eosinophil cationic protein (ECP) in peripheral blood and inhypertonic saline induced sputum were measured 24 hours after allergen inhalation.
RESULTS—Salmeteroleffectively inhibited both early and late asthmatic responses incomparison with placebo. Salmeterol also inhibited the increase in thepercentage of eosinophils in the sputum 24hours after allergeninhalation (median (range) baseline 6% (1-36), after placebo 31%(5-75), after salmeterol 12% (1-63)). However, the increase in bothsputum and serum ECP concentrations 24 hours after allergen challengewas not affected by pretreatment with salmeterol.
CONCLUSIONS—A singledose of salmeterol inhibits the allergen induced airway responses andthe increase in sputum eosinophils after allergen challenge.