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

Abstract

BACKGROUND: 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. METHODS: 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. RESULTS: The IPF patients consisted of 55 men and 30 women. The mean age was 61 ± 8 years. 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). CONCLUSIONS: 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.