title: Association of ET-1 gene polymorphisms with COPD phenotypes in a Caucasian population.
abstract: OBJECTIVE
  The phenotypic expression of COPD consists of pulmonary emphysema and chronic bronchitis. An imprecise phenotypic definition may result in inconsistencies among genetic studies regarding COPD pathogenesis. Endothelin-1 gene polymorphisms have been linked to increased susceptibility of COPD development. The present study examined the involvement of +138 insA/delA and G198T ET-1 polymorphisms with emphysematous and bronchitic COPD phenotypes.
  
  
  METHODS
  In order to narrow down the phenotypic choices to either COPD-associated pulmonary emphysema or chronic bronchitis, a DLCO < 60% predicted threshold was chosen as an indicator of severe emphysema. 116 COPD smokers and 74 non-related, non-COPD smokers were evaluated.
  
  
  RESULTS
  Statistical analysis showed that the 4A allele of the +138insA/delA SNP and the 4A:T haplotype were associated predominantly with a chronic bronchitis phenotype, whereas the TT genotype of the G198T SNP was found to be protective from emphysema development.
  
  
  CONCLUSIONS
  The presence of both the 4A and T allele seems to modify the final expression of COPD towards a chronic bronchitis phenotype, since the G:3A haplotype was associated with a predominantly emphysematous phenotype in our study.
authors.affiliation: Pulmonary Department, Division of Internal Medicine, University Hospital of Patras, Greece. pneumonas@hotmail.com
authors.forename: A
authors.initials: A
authors.lastname: Kaparianos
authors.forename: F
authors.initials: F
authors.lastname: Sampsonas
authors.forename: D
authors.initials: D
authors.lastname: Lykouras
authors.forename: G
authors.initials: G
authors.lastname: Efremidis
authors.forename: P
authors.initials: P
authors.lastname: Drakatos
authors.forename: K
authors.initials: K
authors.lastname: Karkoulias
authors.forename: C
authors.initials: C
authors.lastname: Gogos
authors.forename: K
authors.initials: K
authors.lastname: Spiropoulos
mesh_terms: D019332:Endothelin-1 / Q000235:genetics*; D005541:Forced Expiratory Volume; D005828:Genetics, Population; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D029424:Pulmonary Disease, Chronic Obstructive / Q000235:genetics*; D044465:White People / Q000235:genetics*
chemical_list: D019332:Endothelin-1