title: Association between IL-18 polymorphisms, serum levels, and HBV-related hepatocellular carcinoma in a Chinese population: a retrospective case-control study.
abstract: BACKGROUND
  Interleukin (IL)-18 gene polymorphisms have been found to play multiple roles in various diseases. However, studies focused on its involvement in hepatocellular carcinoma (HCC) remains controversial, and no much study has taken IL-18 serum levels into consideration. This study investigates the association between IL-18 polymorphisms and risk of hepatitis B virus-related HCC and their impact on serum IL-18 serum levels.
  
  
  METHODS
  A total of 153 patients and 165 healthy controls were enrolled in this study. Polymorphisms at positions -607C/A and -137G/C in the IL-18 gene were determined using the polymerase chain reaction-restriction fragment length polymorphism method. Serum IL-18 levels were determined with an ELISA kit.
  
  
  RESULTS
  No relationship was found between the -607C/A polymorphism and an individual's susceptibility to HCC. For the -137G/C polymorphism, the GC genotype and C allele were found to be significantly associated with decreased HCC risk (OR 0.506, 95% CI 0.290-0.882, P = 0.016 and OR 0.520, 95% CI 0.332-0.814, P = 0.004, respectively). The A(-607)C(-137) haplotype was also associated with a significant decreased risk of HCC (OR 0.495, 95% CI 0.294-0.834, P = 0.007). Serum IL-18 levels were found to be significantly lower in HCC patients compared to the control group in both the overall population and subjects with the different SNPs. Further, no association was found between serum IL-18 levels and the different genotypes within the same SNP.
  
  
  CONCLUSIONS
  These findings suggest that the -137G/C SNP in IL-18 may be a protective factor against HCC. Nevertheless, none of the studied SNPs was associated with the expression of IL-18.
authors.affiliation: Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021 Guangxi China.
authors.forename: Jingui
authors.initials: J
authors.lastname: Bao
authors.affiliation: Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021 Guangxi China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021 Guangxi China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021 Guangxi China.
authors.forename: Chengzhi
authors.initials: C
authors.lastname: Rong
authors.affiliation: Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021 Guangxi China.
authors.forename: Yanqiong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021 Guangxi China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Huang
authors.affiliation: Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021 Guangxi China.
authors.forename: Liuying
authors.initials: L
authors.lastname: Song
authors.affiliation: Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021 Guangxi China.
authors.forename: Shan
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Clinical Laboratory, First Affiliated Hospital of Guangxi Medical University, Nanning, 530021 Guangxi China.
authors.forename: Xue
authors.initials: X
authors.lastname: Qin
keywords: Hepatocellular carcinoma; Interleukin-18; Polymorphisms