title: Relationship between polymorphisms of genes encoding microsomal epoxide hydrolase and glutathione S-transferase P1 and chronic obstructive pulmonary disease.
abstract: BACKGROUND
  Cigarette smoking is the major risk factor for chronic obstructive pulmonary disease (COPD). However, only 10% - 20% of chronic heavy cigarette smokers develop symptomatic disease. COPD is most likely the result of complex interactions between environmental and genetic factors. Genetic susceptibility to COPD might depend on the variations in enzyme activities that detoxify cigarette smoke products, such as microsomal epoxide hydrolase (mEH) and glutathione S-transferase (GST). In this study, we investigated the relationship between polymorphisms in the genes encoding mEH and glutathione S-transferase P1 (GSTP1) and COPD in a Chinese population.
  
  
  METHODS
  Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was performed to find mEH polymorphism in exon 3 (Tyr113-->His), exon 4 (His139-->Arg) and GSTP1 polymorphism in exon 5 (Ile105-->Val) in 100 COPD patients and 100 age- and sex-matched healthy controls.
  
  
  RESULTS
  The proportion of mEH exon 3 heterozygotes was significantly higher in patients with COPD than that in the control subjects (42% vs 32%). The odds ratio (OR) adjusted by age, sex, body mass index (BMI) and cigarette years was 2.96 (95% CI 1.24 - 7.09). There was no marked difference in very slow activity genotype versus other genotypes between COPD patients and the controls. When COPD patients were non-smokers, the OR of very slow activity genotype versus other genotypes was more than 1.00; and when COPD patients were smokers (current smokers and ex-smokers), the OR was less than 1.00. There was no significant difference in GSTP1 polymorphism adjusted by age, sex, BMI and smoking between COPD patients and the controls.
  
  
  CONCLUSIONS
  mEH exon 3 heterozygotes might be associated with susceptibility to COPD in China. The interaction might exist between mEH genotype and smoke. The gene polymorphism for GSTP1 might not be associated with susceptibility to COPD in the Chinese population.
authors.affiliation: Beijing Institute of Respiratory Medicine, Beijing Chaoyang Hospital, Capital University of Medical Sciences, Beijing 100020, China. luaixiao@sina.com
authors.forename: Dan
authors.initials: D
authors.lastname: Xiao
authors.forename: Chen
authors.initials: C
authors.lastname: Wang
authors.forename: Min-jie
authors.initials: MJ
authors.lastname: Du
authors.forename: Bao-sen
authors.initials: BS
authors.lastname: Pang
authors.forename: Hong-yu
authors.initials: HY
authors.lastname: Zhang
authors.forename: Bai
authors.initials: B
authors.lastname: Xiao
authors.forename: Jing-zhong
authors.initials: JZ
authors.lastname: Liu
authors.forename: Xin-zhi
authors.initials: XZ
authors.lastname: Weng
authors.forename: Li
authors.initials: L
authors.lastname: Su
authors.forename: David C
authors.initials: DC
authors.lastname: Christiani
mesh_terms: D000368:Aged; D004851:Epoxide Hydrolases / Q000235:genetics*; D005260:Female; D005838:Genotype; D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D007527:Isoenzymes / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011110:Polymorphism, Genetic; D029424:Pulmonary Disease, Chronic Obstructive / Q000209:etiology / Q000235:genetics*
chemical_list: D007527:Isoenzymes; C496556:GSTP1 protein, human; D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase; D004851:Epoxide Hydrolases