The effects of rare SERPINA1 variants on lung function and emphysema in SPIROMICS

Victor E. Ortega, Xingnan Li, Wanda K. O'Neal, Lela Lackey, Elizabeth Ampleford, Gregory A. Hawkins, Philip J. Grayeski, Alain Laederach, Igor Barjaktarevic, R. Graham Barr, Christopher Cooper, David Couper, Mei Lan K. Han, Richard E. Kanner, Eric C. Kleerup, Fernando J. Martinez, Robert Paine, Stephen P. Peters, Cheryl Pirozzi, Stephen I. RennardPrescott G. Woodruff, Eric A. Hoffman, Deborah A. Meyers, Eugene R. Bleecker

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Rationale: The role of PI (protease inhibitor) type Z heterozygotes and additional rare variant genotypes in the gene encoding alpha-1 antitrypsin, SERPINA1 (serpin peptidase inhibitor, clade A,member 1), in determining chronic obstructive pulmonary disease risk and severity is controversial. Objectives: To comprehensively evaluate the effects of rare SERPINA1 variants on lung function and emphysema phenotypes in subjects with significant tobacco smoke exposure using deep gene resequencing and alpha-1 antitrypsin concentrations. Methods: DNA samples from 1,693 non-Hispanic white individuals, 385 African Americans, and 90 Hispanics with >20 pack-years smoking were resequenced for the identification of rare variants (allele frequency,0.05) in 16.9 kB of SERPINA1. Measurements and Main Results: White PI Z heterozygotes confirmed by sequencing (MZ; n = 74) had lower postbronchodilator FEV1 (P = 0.007), FEV1/FVC (P = 0.003), and greater computed tomography-based emphysema (P = 0.02) compared with 1,411 white individuals without PI Z, S, or additional rare variants denoted as VR. PI Z-containing compound heterozygotes (ZS/ZVR; n = 7) had lower FEV1/FVC (P = 0.02) and forced expiratory flow, midexpiratory phase (P = 0.009). Nineteen white heterozygotes for five non-S/Z coding variants associated with lower alpha-1 antitrypsin had greater computed tomography-based emphysema compared with those without rare variants. In African Americans, a 59 untranslated region insertion (rs568223361) was associated with lower alpha-1 antitrypsin and functional small airway disease (P = 0.007). Conclusions: In this integrative deep sequencing study of SERPINA1 with alpha-1 antitrypsin concentrations in a heavy smoker and chronic obstructive pulmonary disease cohort, we confirmed the effects of PI Z heterozygote and compound heterozygote genotypes. We demonstrate the cumulative effects of multiple SERPINA1 variants on alpha-1 antitrypsin deficiency, lung function, and emphysema, thus significantly increasing the frequency of SERPINA1 variation associated with respiratory disease in at-risk smokers.

Original languageEnglish (US)
Pages (from-to)540-554
Number of pages15
JournalAmerican Journal of Respiratory and Critical Care Medicine
Volume201
Issue number5
DOIs
StatePublished - Mar 1 2020

Keywords

  • Alpha-1 antitrypsin
  • Chronic obstructive pulmonary disease
  • Emphysema
  • Rare variant
  • SERPINA1

ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine
  • Critical Care and Intensive Care Medicine

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