Transforming growth factor-β1 polymorphisms, airway responsiveness and lung function decline in smokers

Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation in the airways, parenchyma and vessels, which can cause a structural remodeling with increased fibrosis that narrows and fixes the airway lumen. Transforming growth factor-ss 1 (TGF-ss 1), a multifunctional growth factor, was reported to be increased in the airways of COPD patients. In this study, we hypothesized that polymorphisms in the TGF-ss 1 gene would be associated with an accelerated rate of decline of forced expiratory volume in 1 s (FEV1). Three polymorphisms, -509 (C -> T), +869 (T -> C) and +915 (G -> C), located in TGF-ss 1 gene were genotyped. We determined the prevalence of these polymorphisms in 590 continuing smokers who had the fastest (n = 283) and slowest (n = 307) rate of decline of lung function from the NHLBI Lung Health Study. There was no association between these TGF-ss 1 polymorphisms and the rate of decline of FEV1, but in a post-hoc analysis the genotype distribution at +869 was significantly different between high and tow responders to methacholine (P = 0.04). These data suggest that the T-C polymorphism at position +869 in the TGF-ss 1 gene contributes to airway hyperresponsiveness, but not to rapid decline of lung function. (C) 2006 Elsevier Ltd. All rights reserved.