Impact of Gene Polymorphism rs2275913 and Serum IL-17A Levels on Liver Fibrosis Severity Across the Natural History of Chronic Hepatitis B in Indonesia

Background: A complex interplay between viral activity and host immune responses drives the progression of liver fibrosis in chronic hepatitis B. The T helper 17 (Th17) immune pathway, which produces the pro-inflammatory cytokine interleukin-17A (IL-17A), has been implicated in hepatic fibrogenesis. However, the relationship between IL-17A levels, IL-17A G197A (rs2275913) gene SNP, and the degree of liver fibrosis across different phases of the natural history of chronic hepatitis B remains insufficiently explored. Methods: This study employed an analytical observational design with a cross-sectional approach in treatment-naïve patients with chronic hepatitis B. The degree of liver fibrosis was assessed using liver elastography. IL-17A (rs2275913) gene SNP was analysed using Real-Time PCR, while serum IL-17A levels were measured using enzyme-linked immunosorbent assay. Statistical analyses included Spearman’s correlation, the contingency coefficient, the Chi-square test, the Kruskal–Wallis test, and the Mann–Whitney test, with a significance level set at p < 0.05. Results: A total of 76 patients with chronic hepatitis B were included in this study. The phase of disease progression was significantly associated with the degree of liver fibrosis (p = 0.016). Median IL-17A levels increased in parallel with fibrosis severity (p = 0.003), with a particularly significant association observed during the R phase (p = 0.002). However, no significant association was found between the IL-17A G197A (rs2275913) gene SNP and either liver fibrosis severity or serum IL-17A levels. Conclusions: Elevated serum IL-17A levels were associated with greater liver fibrosis severity, particularly during the reactivation phase of chronic hepatitis B. These findings suggest a potential relationship between IL-17A-mediated immune responses and liver fibrosis in patients with chronic hepatitis B.