Role of IL-18 Gene Promoter Polymorphisms, Serum IL-18 Levels, and Risk of Hepatitis B Virus-related Liver Disease in the Guangxi Zhuang Population: a Retrospective Case-Control Study

Abstract

<b>Background:</b> The aim of this study was to assess the relationship between IL-18 gene polymorphismsand HBV-related diseases and whether these polymorphisms influence its expression in the Guangxi Zhuangpopulation. Materials and <br/><b>Methods</b>: We enrolled 129 chronic HBV infected (CHB) patients, 86 HBV-related livercirrhosis (LC) patients and 160 healthy controls in our study. Polymerase chain reaction-restriction fragmentlength polymorphism methods were used to detect IL-18 gene -607C/A, -137G/C polymorphisms, and an ELISAkit was employed to determine serum IL-18 levels. <br/><b>Results</b>: No correlation was found between the -607C/Apolymorphism and risk of HBV-related disease. For the -137G/C polymorphism, the GC genotype and C allelewere associated with a significantly lower risk of CHB (95%CI: 0.32-0.95, p=0.034 and 95%CI: 0.35-0.91,p=0.018) and HBV-related LC (95%CI: 0.24-0.89, p=0.022 and 95%CI: 0.28-0.90, p=0.021). A similar decreasedrisk was also found with the A-607C-137 haplotype. With respect to IL-18 expression, it was significantly lowerin both patient groups, but no association was noted between the two polymorphisms in the IL-18 gene and itsexpression. <br/><b>Conclusions</b>: Our study indicated that the -137C allele in the IL-18 gene may be a protective factorfor HBV-related disease, and serum IL-18 level may be inversely associated with CHB and HBV-related LC.