Genetic polymorphisms of peptidase inhibitor 3 (elafin) are associated with acute respiratory distress syndrome

Am J Respir Cell Mol Biol. 2009 Dec;41(6):696-704. doi: 10.1165/rcmb.2008-0410OC. Epub 2009 Feb 27.


Peptidase inhibitor 3 (PI3, elafin) is a protease inhibitor produced locally in the lung, where it plays a central role in controlling excessive activity of neutrophil elastase. Our previous study revealed that PI3 gene expression is down-regulated during the acute stage of acute respiratory distress syndrome (ARDS). We conducted a case-control study to investigate whether genetic variants in PI3 gene are associated with ARDS development. Based on resequencing data from 29 unrelated white subjects, three tagging single-nucleotide polymorphisms were selected and genotyped in a prospective cohort consisting of 449 white patients with ARDS (cases) and 1,031 critically ill patients (at-risk control subjects). We found that the variant allele of rs2664581 (T34P) was significantly associated with increased ARDS risk (odds ratio [OR], 1.35; 95% confidence interval [CI], 1.09-1.67; P = 0.006; false discovery rate adjusted P = 0.018). Moreover, this association was stronger among subjects with extrapulmonary injury. The common haplotype Hap2 (TTC), containing the variant allele of rs2664581, was also identified as a risk haplotype for ARDS (OR, 1.31; 95% CI, 1.05-1.64; P = 0.015). Furthermore, the rs2664581 polymorphism was associated with circulating PI3 levels in multivariate analyses. Patients with ARDS homozygous for the wild-type A allele of rs2664581 showed significant lower PI3 plasma level (P = 0.019) at ARDS onset as compared with those homozygous or heterozygous for the variant C allele. Our data suggest that polymorphisms in PI3 gene are significantly associated with ARDS risk and with circulating PI3 levels.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Alleles
  • Case-Control Studies
  • Cohort Studies
  • Elafin / blood
  • Elafin / genetics*
  • Female
  • Genetic Predisposition to Disease
  • Haplotypes
  • Heterozygote
  • Homozygote
  • Humans
  • Male
  • Middle Aged
  • Mutagenesis, Insertional
  • Polymorphism, Genetic*
  • Polymorphism, Single Nucleotide
  • Prospective Studies
  • Respiratory Distress Syndrome / blood
  • Respiratory Distress Syndrome / genetics*
  • Respiratory Distress Syndrome / mortality
  • Risk Factors
  • Sequence Deletion


  • Elafin
  • PI3 protein, human