A single nucleotide polymorphism of the interferon-γ gene and susceptibility to hepatitis B virus-related cirrhosis: a randomized controlled trial.

Objective: This study aimed to explore the correlation between a single nucleotide polymorphism (SNP) of the interferon-γ (IFN-γ) gene and susceptibility to hepatitis B virus (HBV) -related cirrhosis in the Chinese population.

Method: PCR-LDR was employed for the genotyping of two SNPs, rs1861494 and rs2069718, of the IFN-γ gene in 230 patients with HBV-related cirrhosis and 320 inactive HBsAg carriers without cirrhosis. It was then determined whether the Hardy-Weinberg (H-W) equilibrium was satisfied. The odds ratio (OR) and 95% confidence interval (CI) were analyzed using the chi-square test and univariate non-conditional logistic regression. Haplotypes were established using SHEsis and SNPStats online software and their interaction with non-genetic factors was analyzed.

Results: Compared with the AA genotype of rs1861494 SNP, AG+GG genotypes increased the risk of HBV-related cirrhosis. There was a significant difference in the distribution of A and G alleles between the case group and the control group (P<0.05). There was also a significant difference in the distribution of AA, AG, GG, AA, and AG+GG genotypes and A/G alleles between the case group and the control group (P<0.05). This indicated that the G allele may be a risk factor for HBV-related cirrhosis. By analyzing the different distribution of haplotypes in the case group and the control group, we observed significant differences in the distribution of AA, AG and GA haplotypes between the case and control groups (P<0.05). Haplotypes of the IFN-γ gene did not interact with other relevant factors.

Conclusion: The G allele of rs1861494 SNP as well as AG and GG genotypes and G allele of rs2069718 SNP may be risk factors of HBV-related cirrhosis. The AA haplotype may be a protective factor for HBV-related cirrhosis, while the AG haplotype is a risk factor for HBV-related cirrhosis.