Interleukin-6 Gene (-174 G>C) Polymorphisms in Patients with Chronic Hepatitis C Virus; A Case-Control Study

Background: Recent studies have suggested that polymorphisms in the Interleukin (IL)-6 gene promoter might be linked to chronic hepatitis C virus (HCV) infection, potentially affecting the infection's outcome. Objectives: The purpose of this study was to determine whether the genetic variant of IL-6 gene polymorphisms (-174 G>C) is associated with HCV in patients compared to control subjects. Methods: Seventy-one patients infected with HCV and 79 healthy individuals referred to a hepatitis clinic in Mashhad, northeast Iran, were enrolled in the study. Blood samples were collected, and laboratory tests, including enzyme-linked immunosorbent assay (ELISA) for HCV antibodies and reverse transcription polymerase chain reaction (RT-PCR) for confirming HCV-positive results, were conducted. Genomic DNA was extracted from whole blood, and the ARMS-PCR method was used for genotyping the IL-6 gene polymorphisms (-174 G>C). Statistical analyses were performed using SPSS version 21 software. Results: The C allele was found to be more frequent in HCV-infected patients compared to controls (P < 0.05; odds ratio [OR] = 2.91, 95% CI: 1.85 - 3.16), but this association was not significant after adjusting for confounders. Additionally, in a recessive model analysis (CC vs. GG + GC), the CC genotype was more prevalent among HCV-infected patients than in healthy individuals, though not significantly (P = 0.21; OR = 2.91, 95% CI: 0.55 - 15.53). The GG polymorphism was the most common genotype in both groups (P = 0.44), while the CC genotype was the least common (P = 0.12). Conclusions: The IL-6 gene polymorphism at this position may impart a certain level of risk for HCV infection, with carriers of the C allele potentially more susceptible to this infection. However, to further elucidate the role of this polymorphism in HCV, a larger cohort of HCV-infected patients and healthy individuals may be required.