Footnotes Conflict of interest: No potential conflict of interest relevant to this article was reported.
Hepatitis C virus (HCV) infection is a leading cause of liver disease with an estimated

200 million people infected worldwide.1 If untreated, the inflammatory response to the virus promotes hepatic fibrosis and development of cirrhosis which may be complicated by hepatocellular cancer (HCC). As a result, HCV infection has now become the most common indication for liver transplantation. Unfortunately, HCV reinfection of the graft occurs universally and is associated with an aggressive course Inhibitors,research,lifescience,medical in a proportion of patients, leading to graft cirrhosis in 10%–30% of recipients within 3–5 years.2 Therefore, the 5-year survival of HCV-positive liver transplant Inhibitors,research,lifescience,medical recipients is Selumetinib overall significantly lower than that of HCV-negative patients.2 The goal of HCV treatment is to prevent hepatic (cirrhosis and hepatocellular cancer) and extrahepatic complications by permanently eradicating the virus. At present, the standard of care for treating chronic HCV is the combination of weekly subcutaneous injections of pegylated interferon-α (PegIFNα) and ribavirin (RBV) for 24–48 weeks, depending on the viral

Inhibitors,research,lifescience,medical genotype. Treatment with PegIFNα/RBV needs to be prolonged (6–12 months), and compliance is a necessity. To add to this, the treatment is expensive and is associated with significant side-effects.3 The rate of a sustained

viral response (SVR) following this therapy is at best 50% overall.4–6 Presently, a number of host and viral factors are associated with response to therapy. These include race, viral genotype, alcohol intake, and liver histology Inhibitors,research,lifescience,medical (amount of steatosis and stage of fibrosis).7–10 Genetic diversity of the host contributes to the outcome of HCV infection and antiviral treatment. The sequencing of the human genome together with the development of new technologies, such as Inhibitors,research,lifescience,medical gene expression profiling and high-throughput protein analysis, has provided opportunities for rapid and accurate characterization of gene expression in tissues, and for the detection of individual host genetic polymorphisms. For example, our group has recently identified consistent patterns of gene expression in the pre-treatment liver biopsies which were predictive of treatment response.11 Identification of biomarkers to predict anti-viral treatment response would provide important diagnostic reagents in the management Phosphoprotein phosphatase of HCV and may allow for the development of novel therapeutics for patients with HCV infection. IMMUNITY TO HCV Both the innate and adaptive immune responses are important for viral clearance.12 In innate immunity, a number of innate effector cells and cytokines have been shown to be important for clearance of HCV infection. Natural killer (NK) cells play a key role in the innate anti-viral immune responses to HCV.