Bronchial reactivity to cigarette smoke; relation to lung function, respiratory symptoms, serum-immunoglobulin E and blood eosinophil and leukocyte counts

Study objectives: The aim of the study was to investigate the relationship between the immediate bronchial response to inhaled cigarette smoke [cigarette smoke bronchial reactivity (CBR)] and lung function, respiratory symptoms and markers of allergy and inflammation. Design, participants and measurements: This cross-sectional study included 98 smokers. Their lung function and reversibility to inhaled terbutaline was measured. Their clinical history was obtained, an allergological examination was done, and bronchial reactivity to methacholine and inhaled cigarette smoke was measured. Questionnaires about respiratory symptoms, smoking history and drug usage were completed and a blood sample was obtained. Participants were divided into three groups: with asthma, chronic bronchitis and persons without asthma or chronic bronchitis (the respiratory healthy). Results: Forced expiratory volume in 1sec (FEV1) residuals were independently related to the % fall in FEV1 after 12 cigarette smoke inhalations (DFEV%) in all participants (P<0.01), in asthmatic smokers (P<0.001) and in smokers with chronic bronchitis (P<0.05). In smokers with asthma and chronic bronchitis FEV1 residuals explained 51% and 13% of the variation in DFEV%, respectively, but only 8% (P<0.05) and 1% (N.S.) of the Variation in the methacholine bronchial reactivity. In the total population the presence of wheeze (P<0.01), attacks of breathlessness (P<0.05) and daily expectoration (P<0.001) were related to higher DFEV% readings. Serum immunonoglobulin (ES-IgE) was independently related to DFEV% in all participants (P<0.01), in smokers with chronic bronchitis (P<0.01) and in the respiratory healthy (0.05<P<0.1). The eosinophil brood count was, in similar analyses, related to DFEV% in all participants (P<0.05) and in persons with chronic bronchitis (0.05<P<0.1). Conclusion: Cigarette smoke bronchial reactivity was strongly associated to actual FEV1 in smokers with asthma and bronchitis, overall to most respiratory symptoms and in smokers without asthma to S-IgE. Cigarette smoke bronchial reactivity might be suitable to test further how cigarette smoke influences the pathophysiology of the bronchial wall, especially in smokers with asthma. (C) 2000 HARCOURT PUBLISHERS LTD.