Review
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 7, 2016; 22(13): 3531-3546
Published online Apr 7, 2016. doi: 10.3748/wjg.v22.i13.3531
Genetic variation of occult hepatitis B virus infection
Hui-Lan Zhu, Xu Li, Jun Li, Zhen-Hua Zhang
Hui-Lan Zhu, Xu Li, Zhen-Hua Zhang, Department of Infectious Diseases, the First Affiliated Hospital, Anhui Medical University, Hefei 230022, Anhui Province, China
Jun Li, Zhen-Hua Zhang, School of Pharmacy, Anhui Medical University, Hefei 230032, Anhui Province, China
Author contributions: Zhu HL contributed to analysis and interpretation of data, drafting the article; Li X and Li J contributed to revising the article for important intellectual content; Zhang ZH contributed to conception and design, analysis and interpretation of data, drafting and revising the article for important intellectual content.
Supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China, No. 20093420120005; and the National Science Foundation of China, No. 81273142.
Conflict-of-interest statement: The authors have declared that no potential conflict of interest exists.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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/
Correspondence to: Zhen-Hua Zhang, MD, PhD, Department of Infectious Diseases, the First Affiliated Hospital, Anhui Medical University, 218 Jixi Road, Hefei 230022, Anhui Province, China. zzh1974cn@163.com
Telephone: +86-551-62922912 Fax: +86-551-62922912
Received: October 29, 2015
Peer-review started: October 30, 2015
First decision: November 27, 2015
Revised: December 13, 2015
Accepted: December 30, 2015
Article in press: December 30, 2015
Published online: April 7, 2016
Processing time: 150 Days and 21.9 Hours
Abstract

Occult hepatitis B virus infection (OBI), characterized as the persistence of hepatitis B virus (HBV) surface antigen (HBsAg) seronegativity and low viral load in blood or liver, is a special form of HBV infection. OBI may be related mainly to mutations in the HBV genome, although the underlying mechanism of it remains to be clarified. Mutations especially within the immunodominant “α” determinant of S protein are “hot spots” that could contribute to the occurrence of OBI via affecting antigenicity and immunogenicity of HBsAg or replication and secretion of virion. Clinical reports account for a large proportion of previous studies on OBI, while functional analyses, especially those based on full-length HBV genome, are rare.

Keywords: Hepatitis B virus; Occult; Variation; Hepatitis B surface antigen

Core tip: With error-prone reverse transcription during replication, hepatitis B virus (HBV) displays a high rate of mutation, and a single mutation may affect the biological properties of HBV. Occult HBV infection (OBI) is a special form of HBV infection and a frequent phenomenon. Many previous publications have explored the association of OBI with the “hot spots” mutations that occur within the immunodominant “α” determinant of S proteins. However, there are no reviews available that elaborate on the relationship between OBI and mutations throughout the entire HBV genome. This review attempts to provide a comprehensive summary of HBV genetic variants that have been associated with OBI.