Lack of Genetic Association between Interleukin-18 Gene Polymorphism (rs1946518) and Chronic Hepatitis B Infection

BACKGROUND AND OBJECTIVE: Interleukin 18 is a member of the cytokines that play an important role in the Th1-mediated immune response by inducing interferon-gamma activity in collaboration with Interleukin-12 (IL-18). Interleukin 12 and Interleukin 18 can play an important role in purifying viruses. Considering the importance of IL-18, this study was conducted to investigate the relationship between Interleukin-18 Gene polymorphism (-607 C/A: rs1946518) and the susceptibility to chronic hepatitis B infection. METHODS: In this case-control study, the genomic DNA of 115 patients with chronic hepatitis B (with positive results of HBsAg and Anti-HBcAb serology testing) and 115 non-HBV-infected controls (negative results of HBsAg and AntiHbcAb serology testing and no history of liver disease) was extracted by salting-out method and the genotype of singlenucleotide polymorphism (-607 C / A: rs1946518) was sequenced using PCR-RFLP method. FINDING: The genotype frequency of TT, GT, and GG in patients was 40%, 49.6%, and 10.4% in patients, and 41.7%, 42.6%, and 15.7% in the control group, respectively. No significant difference was found between the patients group and the control group. CONCLUSION: Based on the results of this study, there was no clear relationship between IL-18 polymorphism and the potential for chronic hepatitis B infection. Therefore, this polymorphism cannot be a potential factor for chronic hepatitis B.