Endogenous Intrahepatic Interferons and Association with IFN-free HCV Treatment Outcome

Hepatitis C virus (HCV) chronically infects 170 million people worldwide and is a leading cause of liver-related mortality due to hepatocellular carcinoma and cirrhosis1. Standard-of-care treatment is shifting from interferon-alpha (IFNα)-based to IFNα-free directly acting antiviral (DAA) regimens, which demonstrate improved efficacy and tolerability in clinical trials2,3. Virologic relapse after completion of DAA therapy is a common cause of treatment failure, although mechanisms are unclear2,3. We conducted a clinical trial using the DAA sofosbuvir with ribavirin (SOF/RBV)4, and report here detailed mRNA expression analysis of pre- and end-of-treatment (EOT) liver biopsies and blood samples. On-treatment viral clearance was accompanied by rapid down-regulation of interferon-stimulated genes (ISGs) in liver and blood. Analysis of paired liver biopsies from patients who achieved a sustained virologic response (SVR) revealed that viral clearance was accompanied by decreased expression of ISGs, IFNG, and IFNLs, but increased expression of IFNA2. Patients who achieved SVR had higher expression of a hepatic type-I interferon gene signature in unpaired EOT liver biopsies than patients who later relapsed. Together, these results support a model whereby restoration of type-I intrahepatic interferon signaling at the EOT is associated with sustained hepatic HCV suppression and prevention of relapse upon withdrawal of SOF/RBV. Sustained Virologic Response for Chronic Hepatitis C Patients Treated with Sofosbuvir and Ribavirin