Association of HLA and cytokine gene polymorphisms with idiopathic pulmonary fibrosis

Abstract

Idiopathic pulmonary fibrosis (IPF) is a rare, progressive, and lethal interstitial lung disease with unknown etiology. Divergent observations have suggested that genetic factors contribute to IPF susceptibility. This study investigated the relationship between human leukocyte antigen (HLA), cytokine gene polymorphisms, and IPF in a Chinese Han population. The gene polymorphisms of HLA-A, -B, -DRB1, tumor necrosis factor alpha [TNF-α (-308 A/G)], transforming growth factor beta [TGF-β1 (+869 T/C)], interleukin 10 [IL-10 (-592 C/A, -819 T/C, and -1082 G/A)], and interferon gamma [IFN-γ (+874 T/A)] were detected in 102 individuals with IPF and 266 unrelated normal controls using PCR with sequence-specific primers and a high-resolution melt (HRM) approach. The data showed that there was no difference in HLA allele frequencies between the IPF and control groups. However, the data showed the frequency of HLA-A*02-DRB1*04 haplotype in the IPF group was significantly higher than that in the control group [odds ratio (OR) = 4.69, 95% confidence interval (CI) = 1.82-12.08, p < 0.001]. In addition, no differences in the allele and genotype distributions of the cytokines were found between the IPF and control groups (p > 0.01). Our findings suggest that there is an association between specific HLA haplotype and IPF genetic susceptibility and that the genetic variability of some cytokines may not be involved in the pathogenesis of IPF.