title: Occult hepatitis B virus and hepatocellular carcinoma.
abstract: Occult hepatitis B virus (HBV) infection (OBI) is a challenging pathobiological and clinical issue that has been widely debated for several decades. By definition, OBI is characterized by the persistence of HBV DNA in the liver tissue (and in some cases also in the serum) in the absence of circulating HBV surface antigen (HBsAg). Many epidemiological and molecular studies have indicated that OBI is an important risk factor for hepatocellular carcinoma (HCC) development. OBI may exert direct pro-oncogenic effects through the activation of the same oncogenic mechanisms that are activated in the course of an HBsAg-positive infection. Indeed, in OBI as in HBV-positive infection, HBV DNA can persist in the hepatocytes both integrated into the host genome as well as free episome, and may maintain the capacity to produce proteins-mainly X protein and truncated preS-S protein - provided with potential transforming properties. Furthermore, OBI may indirectly favor HCC development. It has been shown that the persistence of very low viral replicative activity during OBI may induce mild liver necro-inflammation continuing for life, and substantial clinical evidence indicates that OBI can accelerate the progression of liver disease towards cirrhosis that is considered the most important risk factor for HCC development.
authors.affiliation: Teresa Pollicino, Department of Pediatric, Gynecologic, Microbiological, and Biomedical Sciences, University Hospital of Messina, 98124 Messina, Italy.
authors.forename: Teresa
authors.initials: T
authors.lastname: Pollicino
authors.affiliation: Teresa Pollicino, Department of Pediatric, Gynecologic, Microbiological, and Biomedical Sciences, University Hospital of Messina, 98124 Messina, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Saitta
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000150:complications / Q000821:virology; D004279:DNA, Viral / Q000032:analysis; D018450:Disease Progression; D016679:Genome, Viral; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006515:Hepatitis B virus; D019694:Hepatitis B, Chronic / Q000150:complications / Q000175:diagnosis / Q000473:pathology*; D022781:Hepatocytes / Q000821:virology; D006801:Humans; D007249:Inflammation; D008099:Liver / Q000473:pathology; D008113:Liver Neoplasms / Q000150:complications / Q000175:diagnosis / Q000821:virology; D012307:Risk Factors; D016896:Treatment Outcome
chemical_list: D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens
keywords: HBx protein; Hepatitis B virus; Hepatitis B virus DNA; Hepatitis B virus surface antigen; Hepatocellular carcinoma; Occult hepatitis B virus infection