BACKGROUNDIdiopathic pulmonary fibrosis (IPF) is a progressive and lethal fibrotic lung disease of unknown etiology. Host susceptibility or genetic factors may be important for the predisposition to it. Transforming growth factor-β1 (TGF-β1, a potent profibrotic cytokine) and plasminogen activator inhibitor 1 (PAI-1) play important roles in the development of pulmonary fibrosis. The objective of the study was to investigate the association between the gene polymorphisms of TGF-β1 869 T > C and PAI-1 4G/5G and the susceptibility to IPF in Han ethnicity.

METHODSPolymerase chain reaction (PCR) and restriction fragment length polymorphism were performed to analyse the gene polymorphisms of TGF-β1 in 869T > C and PAI-1 4G/5G in 85 IPF patients and 85 healthy controls matched in age, gender, race and smoker status.

RESULTSThere was a significant difference in 869T > C genotype distribution of TGF-β1 between IPF cases and controls, a significant negative association between TC genotype and the development of IPF (OR = 0.508, 95%CI: 0.275 - 0.941) and a positive association between CC genotype and the development of IPF (OR = 1.967, 95%CI: 1.063 - 3.641). There was a significant positive association between PAI-1 5G/5G genotype and the development of IPF (OR = 0.418, 95%CI: 0.193 - 0.904).

CONCLUSIONSGene polymorphisms of TGF-β1 in 869T > C and PAI-1 4G/5G may affect the susceptibility to IPF in Han ethnicity. Further investigations are needed to confirm these findings and assess their biological significance in the development of the disease in this ethnic population.