Exposure to environmental tobacco smoke, human E-cadherin C-160A polymorphism, and childhood asthma

摘要

Background Environmental tobacco smoke (ETS) is a risk factor for asthma. Importantly, cigarette smoke can decrease the adherence of epithelial cells and increase detachment. The adhesion molecule E-cadherin (CDH1) has an essential role in the formation of epithelial junction. Turnover of the extracellular matrix, which is characterized by airway remodeling, depends on the imbalance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs). Objective To evaluate the effects of ETS exposure and CDH1, MMP-3, and TIMP-1 genetic polymorphisms on childhood asthma. Methods The CDH1 C-160A, MMP-3 -1171, and TIMP-1 T372C genotypes were identified by polymerase chain reaction in 299 asthmatic children and 383 healthy controls. Results More ETS exposure (>5 vs 0 cigarettes/day; odds ratio [OR], 1.45; 95% confidence interval [CI], 1.05-2.01) and the presence of CDH1 AA/CA genotypes (OR, 1.53; 95% CI, 1.08-2.17) were associated with childhood asthma. Compared with children with less ETS exposure (0-5 cigarettes/day) and the CDH1 CC genotype, those with less ETS exposure and the CDH1 AA/CA genotypes and those with more ETS exposure and the CDH1 CC genotype had a moderate risk of asthma. The greatest risk for asthma was in children with more ETS exposure and the CDH1 AA/CA genotypes (OR, 3.03; 95% CI, 1.81-5.06), and this interaction between CDH1 polymorphism and ETS exposure was significant. In addition, asthma cases with more ETS exposure or the CDH1 AA/CA genotypes had obviously increased eosinophil counts. Conclusion Susceptible CDH1 genotypes might modulate the development of asthma, especially for children exposed to ETS.