Association of Interleukin 28B Polymorphism with Clearance of Hepatitis C Virus: A Mini Review

The highly infectious hepatitis C virus (HCV) is the major cause of chronic hepatitis around the globe. Approximately 3% of the world's population has been affected by both chronic and acute HCV. In this study, we highlight the relationship between single-nucleotide proteins (SNPs) and interleukin (IL) IL28B on chromosome 19 with the treatment response of chronic HCV infection along with its sustained virologic response (SVR). Four SNPs are strongly linked with HCV self-clearance: rs8099917 TT, rs12980275 AA, rs8105790 TT, and rs10853728 CC. Most SNPs, including rs12979860, are located upstream of the IL28B gene fragment, encoding interferon (IFN)-λ3. We find that IL28B variants rs8099917 and rs12979860 strongly influence results of combined pegylated (PEG)-IFN/ribavirin (RBV) therapy. In the case of SNP rs12979860, the CC genotype is linked with greater than a twofold higher SVR than that with TT or CT genotypes. These SNPs are associated with expression of intrahepatic IFN-stimulated genes in liver. Past research shows that females are more efficient in resolving HCV infection, regardless of IL28B genotype. Similar results of IL28B polymorphisms associated with spontaneous HCV clearance were also obtained in Chinese and Taiwanese HCV patients. Another report of RBV and PEG-IFN-treated patients revealed that age, viral load, rs8099917 genotype, and fibrosis were major predictors of antiviral therapeutic response. To select favorable antiviral regimes for treatment using IFN, a combination of host genetic data and viral genotyping may be useful in treating chronic HCV. We propose that these predictive factors must be considered before commencing treatment in HCV patients.