RT Journal Article SR Electronic T1 Lung function of school children with low levels of α1-antitrypsin and tobacco smoke exposure JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 1099 OP 1106 DO 10.1183/09031936.02.00104302 VO 19 IS 6 A1 von Ehrenstein, O.S. A1 von Mutius, E. A1 Maier, E. A1 Hirsch, T. A1 Carr, D. A1 Schaal, W. A1 Roscher, A.A. A1 Olgemöller, B. A1 Nicolai, T. A1 Weiland, S.K. YR 2002 UL http://erj.ersjournals.com/content/19/6/1099.abstract AB Exposure to environmental tobacco smoke (ETS) and other air pollutants has been associated with small decrements in lung function. The susceptibility to pollution exposure may, however, vary substantially between individuals. Children with an impaired protease-antiprotease balance may be particularly vulnerable. Therefore this study aimed to investigate the effects of ETS exposure on children with reduced levels of α1-antitrypsin (α1-AT). Random samples of school children (aged 9–11 yrs) (n=3,526) were studied according to the International Study of Asthma and Allergies in Childhood (ISAAC) phase II protocol, including parental questionnaires, pulmonary function and allergy testing. Blood samples were obtained to measure plasma levels of α1-AT and to genotype for pleomorphic protein inhibitor (Pi)Z and PiS alleles. Children with low levels of α1-AT (≤116 mg·dL−1) showed significant, albeit small decrements in baseline lung function. When exposed to ETS, pronounced decrements of pulmonary function, particularly in measures of mid- to end-expiratory flow rates, were seen in these children as compared to exposed children with normal levels of α1-AT. The mean levels of % predicted±se in both groups were: maximum expiratory flow at 50% of vital capacity 79.4±7.2 versus 99.0±1.5, maximum expiratory flow at 25% of vital capacity 67.4±10.0 versus 100.3±2.1, maximal midexpiratory flow 73.7±8.6 versus 99.9±1.7. These findings suggest that school children with low levels of α1-antitrypsin are at risk of developing pronounced decrements in pulmonary function, particularly if they are exposed to environmental tobacco smoke. Parents of children with heterozygous α1-antitrypsin deficiency resulting in significantly reduced blood concentrations should be advised to prevent their children from being exposed to environmental tobacco smoke and dissuade them from taking up smoking. This Work was supported by the Bundesministerium für Bildung, Forschung und Technologie (German Ministry for the Sciences and Technology) and the Center for Environment and Health (Project Environment and Health, Baden-Württemberg).