Polymorphism of IFN-γ (+874 T/A) in Syrian patients with chronic hepatitis B

AIM: This study aimed to investigate the association of IFN- γ +874 (T/A) polymorphism with susceptibility to chronic HBV infection in the Syrian population. BACKGROUND: Accumulating evidence indicate that the inadequate immune responses are responsible for HBV persistency. Therefore, polymorphisms in genes encoding the cytokines, which are responsible for regulation of the immune response, can affect the course and outcome of the infection. The IFN-γ +874 T/A polymorphism affects the expression of IFN-γ, which has been shown to be crucial to HBV clearance. METHODS: In this case-control study, 140 samples were collected (70 healthy individuals, 70 chronic HBV patients), and genomic DNA was isolated. Sequencing and ARMS-PCR were performed to genotype the IFN-γ +874 T/A polymorphism. RESULTS: Results of this study showed an association between IFN- γ +874 T/A polymorphism and the susceptibility to chronic HBV infection (P < 0.05). In addition, results showed that the AA genotype increased the risk of chronicity (OR = 3.05, 95% CI = 1.35 – 6.89), whereas the AT and TT genotypes reduced the risk of chronicity (OR = 0.33, 95% CI = 0.150 – 0.753). CONCLUSION: Results of this study conclude that the IFN- γ +874 T/A polymorphism may be associated with the chronic HBV infection, according to the genetic model AA vs. AT&TT.