Role of Cigarette Smoking in Regulating Allergen-induced Early and Late Responses in Mild Asthmatics

The objective of this study is to determine the effect of cigarette smoking on inflammatory cell recruitment to the lungs after an allergen challenge, in non-smoking and currently smoking mild asthmatic subjects. When comparing non-smoking asthmatics to smoking asthmatics, do differential cell counts obtained from inflammatory cells in induced sputum after allergen challenge differ? Will differential cell counts show a decline in inflammatory cells in the induced sputum of asthmatics who have refrained from smoking for eight weeks? This study is a randomized, case-controlled study. The first part of the study requires smoking and non-smoking subjects who will attend 2 study periods of 3 consecutive days (triad). In each triad, they will be challenged with allergen or diluent by inhalation, in a random order, and each triad is separated by a washout period. In the second part of the study, current smokers will be invited to undergo another allergen challenge 8 weeks of smoking cessation.