Association between IFN-γ genetic polymorphisms and susceptibility to hepatitis B virus infection: A meta-analysis

Association of an IFN-γ variant with susceptibility to chronic hepatitis B by the enhancement of HBV DNA replication

Interferon gamma (IFN-γ) is a crucial cytokine in host immune response to hepatitis B virus (HBV) infection. This study aimed to determine whether a functional polymorphism +874T/A in IFN-γ gene linked to high and low producer phenotypes [IFN-γ (+874T^high → A^low)] may alter the outcomes of chronic HBV infection in Tunisian population. The +874T/A was analysed by ARMS-PCR method in the group of 200 patients chronically infected with HBV and 200 healthy controls. We observed that minor +874A allele, minor +874AA and +874TA genotypes were significantly more frequent in the chronic hepatitis B group in comparison to the control group [49 vs. 31%, P < 10^-4; 24 vs. 13%, P < 10^-4; 52 vs. 38%, P < 10^-4; respectively]. Besides, they were associated with susceptibility to hepatitis B infection [OR = 2.15, 3.87 and 2.84, respectively]. The minor +874A allele and +874AA genotype were statistically more representative in the sub-group of patients with high viral DNA load when compared with the sub-group of patients with low HBV DNA load [(57% vs. 43%, P = 0.003, OR = 1.79); (33% vs. 14%, P = 0.003, OR = 3.59), respectively]. Collectively, our study suggests an association between the IFN-γ +874T/A SNP and persistence of HBV by the enhancement of HBV DNA replication.

Genetic polymorphisms of interleukin-6 influence the development of hepatitis B virus-related liver cirrhosis in the Han Chinese population

BACKGROUND

Interleukin-6 (IL-6) plays an important role in chronic inflammation. Thus, we aimed to investigate the effects of IL-6 polymorphisms on predicting the progression of hepatitis B virus (HBV)-r elated liver cirrhosis.

METHODS

A cross-sectional study was conducted to analyse IL-6 polymorphisms and serum levels of IL-6 in HBV-infected patients at different clinical phases and in healthy controls. IL-6 polymorphisms were detected by the TaqMan PCR method, and plasma IL-6 levels were assessed by ELISA.

RESULTS

Our analysis included 182 chronic hepatitis B (CHB) patients, 190 HBV-infected liver cirrhosis cases, 125 inactive HBsAg carriers, and 246 healthy controls. Seven SNPs in IL-6 including rs10499563, rs17147230, rs1800796, rs2069837, rs1524107, rs2066992, and rs2069852 were analysed. In a haplotype analysis between HBV-infected liver cirrhosis cases and CHB patients, inactive HBV carriers or healthy controls, haplotype CT in block 1 and haplotype GGCGG in block 2 were associated with liver cirrhosis (P <0.05). Moreover, the genotype or allele frequencies were significantly different in IL-6 rs10499563 and rs2069837 when HBV-infected liver cirrhosis patients were compared with CHB patients, inactive HBV carriers or healthy controls. A further study found that compared with that in the healthy controls, inactive HBV carriers or CHB patients, plasma IL-6 was elevated in HBV-infected liver cirrhosis patients.

CONCLUSION

In conclusion, the IL-6 rs10499563 and rs2069837 polymorphisms are associated with incidence of liver cirrhosis may through their effects on IL-6 expression and these two single nucleotide polymorphisms can be used as potential prognostic markers of HBV-related liver cirrhosis.

Single Nucleotide Polymorphisms in IFN-γ Signaling Pathway Associated with Risk of Hepatitis B Virus Infection in Chinese Children

Hepatitis B virus (HBV) infection is a challenging public health problem in China and worldwide. Mother-to-child transmission is one of the main transmission routes of HBV in highly endemic regions. However, the mechanisms of HBV perinatal transmission in children have not been clearly defined. The aim of this study was to demonstrate the association between single-nucleotide polymorphisms (SNPs) in IFN-γ signaling pathway and HBV infection or breakthrough infection in children. Two hundred and seventy-four HBV-infected children defined as test positive for hepatitis B surface antigen (HBsAg) and 353 controls defined as negative for HBsAg in China were recruited from October 2013 to May 2015. SNPs in IFN-γ signaling pathway including IFNG, IFNGR1, IFNGR2, and IL12B were genotyped. Rs2234711 in IFNGR1 was significantly associated with HBV infection in children (OR = 0.641, 95% CI: 0.450–0.913). In addition, rs2234711 was also significantly associated with HBV breakthrough infection in children born to HBsAg-positive mothers (OR = 0.452, 95% CI: 0.205–0.998). Our study confirmed that genetic variants in IFN-γ signaling pathway have significant associations with HBV infection, especially with HBV breakthrough in children. This study provides insight into HBV infection in children and could be used to help design effective strategies for reducing immunoprophylaxis failure.