Review
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Meta-Anal. Apr 28, 2020; 8(2): 67-77
Published online Apr 28, 2020. doi: 10.13105/wjma.v8.i2.67
Pathological characterization of occult hepatitis B virus infection in hepatitis C virus-associated or non-alcoholic steatohepatitis-related hepatocellular carcinoma
Hatem Elalfy, Tarek Besheer, Dina Elhammady, Ahmed El Mesery, Shaker Wagih Shaltout, Mohamed Abd El-Maksoud, Ahmed I Amin, Ahmed Nasr Bekhit, Mahmoud Abd El Aziz, Mahmoud El-Bendary
Hatem Elalfy, Tarek Besheer, Dina Elhammady, Ahmed El Mesery, Mohamed Abd El-Maksoud, Mahmoud Abd El Aziz, Mahmoud El-Bendary, Endemic Medicine Department, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt
Shaker Wagih Shaltout, Tropical Medicine Department, Faculty of Medicine, Port Said University, Port Said 42511, Egypt
Ahmed I Amin, Internal Medicine Department, Faculty of Medicine, Port Said University, Port Said 42511, Egypt
Ahmed Nasr Bekhit, Tropical Medicine Department, Zagazig General Hospital, Zagazig 44511, Egypt
Author contributions: Elalfy H collected the data; Besheer T, Elhammady D, El Mesery A, Shaker Shaltout W, Abd El-Maksoud M, Amin AI, Bekhit AN, Abd El Aziz M and El-Bendary M wrote the paper.
Conflict-of-interest statement: Authors declare no conflict of interests related to this article.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Hatem Elalfy, MD, Assistant Professor, Endemic Medicine Department, Faculty of Medicine, Mansoura University, Mansoura 35516, Egypt. elalfy2004@mans.edu.eg
Received: November 12, 2019
Peer-review started: November 12, 2019
First decision: December 20, 2019
Revised: January 8, 2020
Accepted: April 10, 2020
Article in press: April 10, 2020
Published online: April 28, 2020
Abstract

Occult hepatitis B virus (HBV) infection, by definition, is a state in which infection with this virus does not manifest with the conventional diagnostic laboratory criteria reserved for the obvious form of HBV infection. As a result, occult HBV infection is commonly a surprise finding discovered accidently during the evaluation of other apparent liver diseases, such as hepatitis C virus (HCV) infection or non-alcoholic fatty liver disease and, more importantly, their evolution into life-threatening hepatocellular carcinoma. As infection with HCV and occult HBV is rarely considered when assessing these more obvious conditions, and in an attempt to offer a better understanding of this phenomenon, this study attempted to shed some light onto the uniqueness of occult HBV infection by addressing the natural history of HBV and HCV infections, as well as non-alcoholic fatty liver disease. This was carried out by taking into account the exclusive integration process undertaken by the HBV genome into infected host hepatocytes, with consideration given to conditions which afford reactivation of the occult infection and stress on the molecular mechanisms that underlie occult HBV infection. Finally, the clinical outcome of occult HBV infection and its relation to hepatocellular carcinoma is analyzed.

Keywords: Occult hepatitis B virus, Hepatitis C virus, Non-alcoholic fatty liver disease, Hepatocellular carcinoma, Clinical outcome, Pathophysiology of occult hepatitis B virus

Core tip: Occult hepatitis B infection is a common clinical situation among chronic liver diseases including hepatitis C virus infection and non-alcoholic fatty liver disease. It is masked, not routinely diagnosed by common laboratory tools, it has a different clinical impact and may increase the incidence of hepatocellular carcinoma in patients with these chronic liver diseases. This systematic review analyzes the data on this clinical situation and highlights different studies which have investigated this clinical entity.