T869C polymorphism in the transforming growth factor-β1 gene may be associated with the predisposition to idiopathic pulmonary fibrosis in Korean

Abstract

[한글]

[영문]Background: Transforming growth factor-β1 (TGF-β1) is a key cytokine that plays a critical role in the development of idiopathic pulmonary fibrosis (IPF). The genotypes of T869C polymorphism are associated with the predisposition 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 age- and sex-matched 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. With regard to smoking status, fifty-one (60%) of the 85 IPF patients were smokers, and 34 non-smokers. The distribution of genotypes in IPF patients was TT 37 cases (43.5%), and TC or CC 48 cases (56.5%). It was significantly different from that of the controls (TT 27.1%, and TC or CC 72.9%, p=0.039). The presence of TT genotype was significantly associated with a reduction in PaO2 and a increase in D(A-a)O2 upon initial diagnosis (t-test, p=0.006 and 0.009, respectively), but TT genotype was not associated with disease progression or survival. Conditional logistic regression including smoking status and genotype of TGF-β1 T869C polymorphism suggested that the TT genotype carried a 2 fold higher risk of IPF development, as compared with the TC or CC genotype (95% CI 1.053~3.799, p=0.034).Conclusions: This study suggests that TGF-β1 gene T869C polymorphism may be associated with a predisposition to IPF in Korea. Larger studies are required to confirm genetic association for TGF-β1 gene polymorphism and IPF.