Association between interleukin-18 gene polymorphisms and hepatocellular carcinoma caused by hepatitis B virus

Abstract

To investigate the association between the single nucleotide polymorphisms (SNPs) IL-18-137G/C (rs187238) and IL-18-607A/C (rs1946518) in interleukin-18 (IL-18) gene and hepatocellular carcinoma (HCC) caused by the hepatitis B virus (HBV). The subjects were divided into HBV-related HCC group (109 patients), chronic HBV infection group (113 patients), and healthy control group (127 patients). The polymerase chain reaction-ligase detection reaction (PCR-LDR) was used to determine the alleles and genotypes of the two SNPs IL-18-137G/C and IL-18-607A/C. The t-test and chi-square test were used for baseline data. The chi-square test was used to investigate the differences in genotype and allele frequencies across the three groups. Non-conditional logistic regression analysis was used to compare the odds ratios (ORs) and 95% confidence intervals (CIs) for different genotypes/alleles in predicting the risk of HBV-related HCC. The HBV-related HCC group showed significantly higher AA genotype and A allele frequencies of the SNP IL-18-607A/C than the healthy control group (AA genotype frequency: 29.4% vs 18.1%, χ (2) = 4.152, P < 0.05; A allele frequency: 54.6% vs 44.1%, 5.169, P < 0.05), which were positively correlated with the risk of HBV-related HCC (AA genotype frequency: OR = 1.879, 95% CI: 1.020-3.464; A allele frequency: OR = 1.524, 95% CI: 1.059-2.193). The chronic HBV infection group had a significantly higher A allele frequency of the SNP IL-18-607A/C than the healthy control group (54.0% vs 44.1%, χ (2) = 4.680, P < 0.05), which was positively correlated with the risk of chronic HBV infection (OR = 1.487, 95% CI: 1.037-2.132). The genotype and allele frequencies of the SNP IL-18-607A/C showed no significant differences between the HBV-related HCC group and the chronic HBV infection group (P > 0.05). The genotype and allele frequencies of the SNP IL-18-137G/C showed no significant differences between any two groups of the three groups (P > 0.05). The AA genotype and A allele frequencies of the SNP IL-18-607A/C are positively correlated with the morbidity of HBV-related HCC, and the A allele frequency of the SNP IL-18-607A/C is positively correlated with the morbidity of chronic HBV infection.