TGF-β1 T869C Polymorphism May Affect Susceptibility to Idiopathic Pulmonary Fibrosis and Disease Severity

Abstract

Transforming growth factor-β1 (TGF-β1) is a key cytokine that plays a critical role in idiopathic pulmonary fibrosis (IPF). The genotypes of T869C polymorphism may be associated with the susceptibility to fibrotic lung disease. We investigated a single-nucleotide polymorphism at exon 1 nucleotide position 29 (T→C) of the TGF-β1 gene. Eighty-five healthy controls and 85 subjects with surgically confirmed IPF were investigated using polymerase chain reaction and restriction enzyme fragment length polymorphism techniques. The IPF patients consisted of 55 men and 30 women. The mean age was 61±8years. Fifty-one (60%) of the 85 IPF patients were smokers and 34 were nonsmokers. The distribution of genotypes between IPF patients and controls was significantly different (IPF: TT 43.5% and TC or CC 56.5%; controls: TT 27.1% and TC or CC 72.9%, p=0.037). TT genotype was significantly associated with decreased PaO2 and increased D(A-a)O2 upon initial diagnosis (p=0.006 and 0.009, respectively). There was a positive association between TT genotype and IPF development (odds ratio [OR]=2.1, 95% confidence interval [CI]=1.1-4.0, p=0.028). This study suggests that the TGF-β1 gene T869C polymorphism may affect susceptibility to IPF in Koreans. Larger studies are required to confirm the genetic association of TGF-β1 gene polymorphism and IPF.