ECLIPSE was a three year observational study conducted at 46 centers in 12 countries [14]. ECLIPSE recruited 2083 COPD subjects ages 40–75 with a smoking history of at least 10 pack-years (cigarettes smoked per day multiplied by years smoked, divided by 20 to convert to packs), 332 control smokers with at least 10 pack-years smoking history and normal lung function, and 237 non-smoking controls [15]. COPD was defined by GOLD stage 2 or greater (FEV1/FVC<0.7 with FEV1<80% predicted) [10]. Genome-wide SNP genotyping was performed on all ECLIPSE subjects using the Illumina HumanHap550 BeadChip. GWAS analysis included 1736 cases COPD cases and 175 controls [11]. Sputum induction was performed on a subset of COPD cases at 14 sites, using a standard protocol [16]. RNA was extracted from sputum cell pellets using TRIzol and amplified with the Nugen Ovation RNA Amplification kit. Gene expression profiling was performed on RNA extracted from sputum samples of 145 COPD cases (all ex-smokers) using the Affymetrix Human U133 Plus2 array [17]. MIAME-compliant array data are available in the Gene Expression Omnibus database (http://www.ncbi.nlm.nih.gov/geo), accession GSE22148. Only Caucasian subjects were included in this analysis.
