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

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.

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

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.

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).

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