IL-6 polymorphism in patients with hepatitis B virus infection
Previous studies reported an association between some cytokines polymorphisms and human viral infections. In HBV infection, IL-6 plays a role in the induction of immune tolerance by inhibiting IL-1 and tumor necrosis factors, which exert anti-inflammatory properties and prevent cell damage. IL-6 has a potential role in HBV-induced hepatocellular carcinoma, liver fibrosis, and liver cirrhosis. IL-6 levels increased in subjects infected with hepatitis B virus, and genetic susceptibility was reported in viral infection. This study aims to determine IL-6 polymorphism in humans infected with hepatitis B virus. In this case-control study, 50 individuals with hepatitis C virus infection were included. The -174G/C promoter polymorphism of the IL-6 gene by Amplification Refractory Mutation System Polymerase Chain Reaction (ARMS-PCR) procedure. There were highly significant differences in (-174G/C) promoter polymorphism of IL-6 between the control group and the patients group. Two homozygous GG and CC genotypes were in patients, while one heterozygous (GC) and one homozygous (GG) genotype pattern was detected in controls. The GG and CC IL-6 (-174G/C) genotypes were predominant in patients compared to controls. In contrast, the GC IL-6 genotype was present in 52.5% of the controls, and none was found in HBV-infected patients. IL-6 GG genotype and G allele may be associated with HBV infection susceptibility in Iraqi subjects, and IL-6 gene plays a potential role in the pathogenicity of HBV infection. However, a large-scale study that included many positions was warranted.