Pharmacogenomic Testing in the Era of Patient-Tailored HCV Treatment

Abstract

Hepatitis C affects approximately 180 million people worldwide, with 3-4 million newly infected each year. Hepatitis C virus (HCV) has been classified into seven different genotype categories, wherein HCV genotype 1 (HCV-1) is the most prevalent. To date, there is still no vaccine available against HCV infection. Until recently, combination therapy of pegylated interferon-a (PegIFN) and ribavirin (RBV) has been the standard of care. Nevertheless, for many patients, particularly those infected with HCV genotype 1 (HCV-1), this treatment has resulted with unsatisfactory treatment response rates and high adverse drug reaction (ADR) rates. Many clinical factors, including pharmacogenetics, influence the treatment response rate. This review focuses on the association between pharmacogenetics and HCV antiviral therapy in patients infected with HCV genotype 1 and other genotypes (GT); patients reinfected with HCV after liver transplantation; and patients coinfected with HCV and human immunodeficiency virus. Data considering triple therapy in HCV-infected patients are also reviewed. Additionally, various genetic polymorphisms, with an emphasis to IL-28B, and their association with pharmacogenetic testing in HCV are discussed.