The Impact of Interleukin-28B rs12979860 Polymorphism on Peginterferon-alpha and Ribavirin Combination Therapy in Iranian Patients with Hepatitis C Virus Genotype 1 Infection

Background: Hepatitis C virus (HCV) infection is a global health problem. Most cases of HCV infection do not resolve spontaneously. Combination therapy with pegylated interferon-α (PegIFN-alpha) and ribavirin (RBV) is the standard treatment for patients with HCV infection. The success of treatment is affected by several host, viral, and treatment factors. Available works have demonstrated significant role of interleukin 28B (IL28B) polymorphisms in predicting HCV infection treatment outcomes. This suggests the possibility of tailored therapy in HCV infected patients. HCV is one of the most common causes of liver disease worldwide. If untreated, this infection can develop chronic hepatitis in 50%-85% of patients. The aim of current study is to determine the association of interleukin-28B (IL-28B) rs-12979860 polymorphism in response to peginterferon-alpha (PegIFN-alpha) and ribavirin combination therapy in Iranian patients with chronic hepatitis C genotype 1 infection. Methods: This cross-sectional study was carried out on 70 Iranian patients with chronic hepatitis C infection (genotype 1) receiving PegIFN-alpha and ribavirin. DNA was extracted from blood samples. Specific primers were used to amplify targeted polymorphisms. Results: In this study, 71.4% of patients reached sustained virological response (SVR). The prevalence of CC, CT and TT genotypes were 38.6%, 42.8% and 18.6% respectively. The rate of SVR was 96.3 for CC genotype, whereas this rate was 66.7 for CT and 30.8 for TT genotypes. We found an association between end of treatment response (ETR) and IL-28B genotypes as 100% of patients bearing CC genotype reached ETR, but ETR rate was 45.85% in CT group and 10.2% in TT group. Six months follow-up showed that there was a significant difference between response to treatment in patients IL-28B-CC and TT (P < 0.001). Data regression analysis showed that CC genotype was an independent predicting factor, significantly associated with higher SVR (P = 0.005 (OR=36.1; 95% CI = 3 - 434.2)). In contrast, absence of C allele (TT genotype) was significantly correlated with the failure of response (P = 0.005 (OR = 36.1; 95% CI = 3 - 434.2)). Conclusions: The results showed that IL-28B rs12979860 was an important predictor of HCV treatment response.