Gene polymorphisms of interleukin 28B and the risk to chronic hepatitis B virus infection in Thai

In this study, we aimed to evaluate the effect of two single nucleotide polymorphisms (SNPs) of interleukin 28B (IL28B) (rs12979860C/T and rs8099917G/T) on chronic hepatitis B virus (CHB) infection in Thai population. We studied 375 subjects: 83 CHB with hepatocellular carcinoma (HCC) patients, 128 CHB without HCC and 164 individuals with self-limited HBV infection, by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and TaqMan allelic discrimination assay. Results revealed significant risk of IL28B rs8099917T allele associated with CHB without HCC compared with self-limited HBV [odds ratio (OR) (95% confidence interval (CI))=2.56 (1.08-6.28), P=0.019]. The effect of this T allele was similar to that of an autosomal recessive gene in the presence of TT genotype compared with GG and GT genotype [OR (95% CI)=2.70 (1.11-6.77), P=0.016, P (logistic regression)=0.048]. The two locus haplotype analysis of the two IL28B SNP loci did not show any association with CHB (P>0.05). In conclusion, these results suggested a IL28B rs8099917T allele predispose for susceptibility to chronic HBV infection but not leading to HCC in Thai population.