Background: Allergen inhalation challenge is a useful clinical model to investigate the effects of asthma therapies on allergen-induced airway responses; however, the repeatability of allergen-induced airway inflammation is not known.
Objective: The purpose of this study was to investigate the repeatability of allergen-induced increases in sputum eosinophils. This information will allow the prediction of the number of subjects required in studies evaluating asthma therapies.