Logo image
Alpha-1 Antitrypsin PiMZ Genotype Is Associated with Chronic Obstructive Pulmonary Disease in Two Racial Groups
Journal article   Open access   Peer reviewed

Alpha-1 Antitrypsin PiMZ Genotype Is Associated with Chronic Obstructive Pulmonary Disease in Two Racial Groups

Marilyn G Foreman, Carla Wilson, Dawn L DeMeo, Craig P Hersh, Terri H Beaty, Michael H Cho, John Ziniti, Douglas Curran-Everett, Gerard Criner, John E Hokanson, …
Annals of the American Thoracic Society, Vol.14(8), pp.1280-1287
08/2017
DOI: 10.1513/AnnalsATS.201611-838OC
PMCID: PMC5566271
PMID: 28380308
url
https://doi.org/10.1513/AnnalsATS.201611-838OCView
Published (Version of record) Open Access

Abstract

Rationale: Alpha-1 antitrypsin deficiency, caused primarily by homozygosity for the Z allele of the SERPINA1 gene, is a well-established genetic cause of chronic obstructive pulmonary disease (COPD). Whether the heterozygous PiMZ genotype for alpha-1 antitrypsin confers increased risk for COPD has been debated. Objectives: We analyzed 8,271 subjects in the Genetic Epidemiology of COPD (COPDGene) Study, hypothesizing that PiMZ would independently associate with COPD and COPD-related phenotypes. Methods: The COPDGene Study comprises a multiethnic, cross-sectional, observational cohort of non-Hispanic white and African American current and former smokers with at least 10 pack-years of smoking who were enrolled for detailed clinical and genetic studies of COPD and COPD-related traits. We performed multivariate logistic regression analysis for moderate to severe COPD and assessed Pi genotype with other relevant covariates in models stratified by race. We analyzed quantitative characteristics on the basis of volumetric computed tomography with generalized linear models controlling for genotype, scanner type, and similar covariates. Results: White PiMZ COPDGene subjects had significantly lower lung function, FEV 1 percent predicted (68 ± 28 vs. 75 ± 27; P  = 0.0005), and FEV 1 /FVC ratio (0.59 ± 0.18 vs. 0.63 ± 0.17; P  = 0.0008), as well as more radiographic emphysema ( P  = 0.001), than subjects without alpha-1 antitrypsin Z risk alleles. Similarly, African American PiMZ subjects had lower lung function, FEV 1 percent predicted (65 ± 33 vs. 84 ± 25; P  = 0.009) and FEV 1 /FVC (0.61 ± 0.21 vs. 0.71 ± 0.15; P  = 0.03). Conclusions: In the COPDGene Study, we demonstrate that PiMZ heterozygous individuals who smoke are at increased risk for COPD and obstructive lung function impairment compared with Z-allele noncarriers, regardless of race. Although severe alpha-1 antitrypsin deficiency is uncommon in African Americans, our study adds further support for initial targeted detection of all subjects with COPD for alpha-1 antitrypsin deficiency, including African Americans. Clinical trial registered with www.clinicaltrials.gov (NCT00608784).
African Americans Genetics alpha-1 antitrypsin deficiency Original Research chronic obstructive pulmonary disease emphysema

Details

Logo image