Autoimmune hepatitis association with single nucleotide polymorphism of interleukin-2, but not interferon-gamma

Background: Autoimmune hepatitis (AIH) is a chronic inflammation in hepatocellular tissues associated with circulating autoantibodies. Imbalance in T-cells population and dysregulation in several cytokine profiles has been implicated in pathogenesis of AIH. This study was performed to assess potential association of AIH with interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) genes single nucleotide polymorphisms (SNPs). Methods: Fifty-six patients with AIH and 139 healthy individuals were enrolled in this study. IL-2 and IFN-gamma typing was performed, using polymerase chain reaction with sequence-specific primers (PCR-SSP) assay. The frequencies of alleles, genotypes and haplotypes in AIH patients were compared to healthy controls. Results: IL-2 T allele at position + 166 (rs2069763) showed significant higher frequency in AIH group (36%), compared to the controls (21%) (OR = 2.06; 95% CI, 1.24-3.43, P-value < 0.01). The frequency of IL-2 TT genotype at + 166 position was also associated with AIH (OR = 18.68, 95% CI 3.74-126.04, P-value < 0.01). G/T alleles of IL-2 at -330 (rs2069762) and A/T alleles on UTR 5644 position at IFN-gamma and their subsequent haplotypes, did not show significant association with AIH. Conclusions: This study identified IL-2 T allele at + 166 position and TT genotype as susceptibility gene in AIH which would provide better understandings into the mechanisms of AIH and potential immune modulation therapies. (C) 2017 Elsevier Masson SAS. All rights reserved.