Single nucleotide insertion in the 5'-untranslated region of hepatitis C virus with clearance of the viral RNA in a liver transplant recipient during acute hepatitis B virus superinfection

Hepatitis C virus (HCV) infection is an important etiology in patients undergoing orthotopic liver transplantation (OLT) world-wide. Antiviral therapy-related clearance of HCV RNA may occur both in patients with chronic HCV infection and in transplanted patients for HCV-related liver cirrhosis, but the role of the 5'-untranslated region (UTR) of HCV containing the internal ribosome entry site (IRES), which directs the translation of the viral open reading frame has not hitherto been evaluated. We studied the 5'-UTR in an HCV-infected recipient of a liver graft that showed spontaneous clearance of HCV RNA during an acute hepatitis B virus (HBV) superinfection. Sequencing of the 5'-UTR of HCV showed a nucleotide A insertion at position 193 of the IRES.