The Influence of Foxp3 Treg Cell Gene Polymorphism (rs3761548) on FoxP3 Gene Expression in Patients with Chronic Hepatitis B Virus Infection

Immune responses are pivotal in hepatitis B virus (HBV) infection, where Regulatory T cells (Treg) can contribute to sustaining the infection by suppressing immune responses. Forkhead box P3 (FoxP3) is the central regulator of Treg cells. In this case-control study, we investigated the role of FoxP3 -3279 (rs3761548) C/A polymorphism in the context of HBV infection. The study encompassed 140 healthy individuals as the control group and 70 individuals with chronic hepatitis B virus (CHBV) as the case group. The rs3761548 polymorphism was analyzed using the restriction fragment length polymorphism-PCR (PCR-RFLP) method. Furthermore, we evaluated FoxP3 gene expression in both HBV-positive and control groups using Real-Time PCR. The results revealed that the frequency of the AA genotype in the case and control groups was 52.9% and 44.3%, respectively, yielding an odds ratio (OR) of 1.411 with a 95% confidence interval (CI) ranging from 0.793 to 2.509. However, this difference did not achieve statistical significance (P = 0.242). Notably, the AC genotype was significantly more prevalent in the control group compared to the case group (P = 0.000). Moreover, FoxP3 gene expression was significantly higher in CHBV infection cases compared to the control group (P = 0.000). These findings suggest that the observed polymorphism may play a role in the pathogenesis and persistence of HBV infection. Nevertheless, further research is warranted to comprehensively investigate this phenomenon.