The principal determining factors influencing the development of the airway disease and emphysema components of chronic obstructive pulmonary disease (COPD) have not been clearly defined. Genetic variability in COPD patients might influence the varying degrees of involvement of airway disease and emphysema. Therefore, we investigated the genetic association of single nucleotide polymorphisms (SNPs) in COPD candidate genes for association with emphysema severity and airway wall thickness phenotypes.
Polymorphisms in six candidate genes were analysed in 379 subjects of the National Emphysema Treatment Trial (NETT) Genetics Ancillary Study with quantitative chest computed tomography (CT) data. Genetic association with per cent of lung area below -950 HU (LAA950), airway wall thickness, and derived square root wall area (SRWA) of 10-mm internal perimeter airways were investigated.
Three SNPs in EPHX1, five SNPs in SERPINE2 and one SNP in GSTP1 were significantly associated with LAA950. Five SNPs in TGFB1, two SNPs in EPHX1, one SNP in SERPINE2 and two SNPs in ADRB2 were associated with airway wall phenotypes in NETT.
In conclusion, several COPD candidate genes showed evidence for association with airway wall thickness and emphysema severity using CT in a severe COPD population. Further investigation will be required to replicate these genetic associations for emphysema and airway wall phenotypes.
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This manuscript is subject to the NIH Public Access Policy (http://publicaccess.nih.gov/). This study was funded by the following grants. NIH R01 HL075478, P01 HL083069, R01 HL084323, U01 HL089856, K23HL089353, and the Parker B. Francis Foundation. Funding was also provided by GlaxoSmithKline.
Statement of Interest
Statements of interest for E. Hoffman and E.K. Silverman, and for the study itself can be found at www.erj.ersjournals.com/site/misc/statements.xhtml
- Received November 1, 2009.
- Accepted April 28, 2010.
- ©ERS 2011