FOXP3 polymorphisms in interstitial lung disease among Chinese Han population: A genetic association study.

INTRODUCTION

Both genetic and environmental factors are implicated in the pathogenesis of interstitial lung disease (ILD). Single-nucleotide polymorphisms (SNPs) in FOXP3 genes were implicated in the causation of some autoimmune diseases; however, association of these genes and ILD has not been reported.

OBJECTIVES

To investigate whether FOXP3 polymorphisms are associated with ILD in a representative Chinese population.

METHODS

One hundred and fifty-seven ILD patients and 170 healthy controls were recruited; SNPs were genotyped by the Sequenom MassARRAY platform and SHEsis was used to estimate the haplotype frequencies of SNPs.

RESULTS

The CC and TC genotypes of FOXP3 rs2280883 were associated with a significantly higher risk of connective tissue disease-associated ILD (CTP-ILD) than the TT genotype (P = .006). Patients with idiopathic interstitial pneumonia (IIP) showed a significantly higher frequency of rs3761547 (GG genotype) and rs3761549 (CC genotype) polymorphisms of FOXP3 as compared to that in controls (P = .038 and P = .026, respectively). The rs2294021 (TC genotype) was less frequently observed among IIP patients as compared to that in controls (P = 0.029). In addition, the FOXP3 CAATC haplotype was associated with a greater risk for CTD-ILD (P =.048) as compared to controls, and the FOXP3 TCCCC haplotype showed an increased IIP risk (P = .001); however, patients with the FOXP3 TACTT haplotype showed a significant protective effect against IIP (P = .036).

CONCLUSION

FOXP3 polymorphisms may be important markers to determine susceptibility to IIP or CTP-ILD in Chinese population.