Observational Study
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Mar 21, 2016; 22(11): 3268-3274
Published online Mar 21, 2016. doi: 10.3748/wjg.v22.i11.3268
Mutations in pre-core and basic core promoter regions of hepatitis B virus in chronic hepatitis B patients
Xiao-Ling Wang, Jian-Ping Ren, Xue-Qing Wang, Xiao-Hong Wang, Shao-Fang Yang, Yi Xiong
Xiao-Ling Wang, Jian-Ping Ren, Xue-Qing Wang, Xiao-Hong Wang, Shao-Fang Yang, Yi Xiong, Department of Clinical Laboratory, Shanxi Provincial Hospital of Traditional Chinese Medicine, Taiyuan 030012, Shanxi Province, China
Author contributions: Wang XL and Ren JP contributed equally to this work; Wang XL, Ren JP and Wang XQ designed the research; Wang XL, Wang XH, Wang XQ, Yang SF, Xiong Y performed this research;; Wang XL contributed new reagents/analytic tools; and Wang XL analyzed the data and wrote the paper.
Supported by Youth Foundation of Health and Family Planning Commission of Shanxi Province, No. 201301024.
Institutional review board statement: The study was reviewed and approved by the Ethic Committee of Shanxi Provincial Hospital of Traditional Chinese Medicine.
Informed consent statement: The authors of this paper guarantee that all study participants or their legal guardian provided informed written consent about personal and medical data collection prior to study enrolment.
Conflict-of-interest statement: There are no conflicts of interest in relation to this manuscript.
Data sharing statement: No additional data are available.
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: Xiao-Ling Wang, MD, Department of Clinical Laboratory, Shanxi Provincial Hospital of Traditional Chinese Medicine, 46 Bingzhou West Street, Yingze District, Taiyuan 030012, Shanxi Province, China. wangxiaoling24@163.com
Telephone: +86-351-4668392
Received: November 8, 2015
Peer-review started: November 8, 2015
First decision: November 27, 2015
Revised: December 14, 2015
Accepted: December 30, 2015
Article in press: December 30, 2015
Published online: March 21, 2016
Abstract

AIM: To investigate the frequency of mutations in pre-core (pre-C) and basic core promoter (BCP) regions of hepatitis B virus (HBV) from Shanxi Province, and the association between mutations and disease related indexes.

METHODS: One hundred chronic hepatitis B patients treated at Shanxi Province Hospital of Traditional Chinese Medicine were included in this study. PCR-reverse dot blot hybridization and mismatch amplification mutation assay (MAMA)-PCR were used to detect the mutations in the HBV pre-C and BCP regions. HBV DNA content and liver function were compared between patients with mutant HBV pre-C and BCP loci and those with wild-type loci. The consistency between PCR-reverse dot blot hybridization and MAMA-PCR for detecting mutations in the HBV pre-C and BCP regions was assessed.

RESULTS: Of the 100 serum samples detected, 9.38% had single mutations in the pre-C region, 29.17% had single mutations in the BCP region, 41.67% had mutations in both BCP and pre-C regions, and 19.79% had wild-type loci. The rates of BCP and pre-C mutations were 65.7% and 34.3%, respectively, in hepatitis B e antigen (HBeAg) positive patients, and 84.6% and 96.2%, respectively, in HBeAg negative patients. The rate of pre-C mutations was significantly higher in HBeAg negative patients than in HBeAg positive patients (χ2 = 26.62, P = 0.00), but there was no significant difference in the distribution of mutations in the BCP region between HBeAg positive and negative patients (χ2 = 2.43, P = 0.12). The presence of mutations in the pre-C (Wilcoxon W = 1802.5, P = 0.00) and BCP regions (Wilcoxon W = 2906.5, P = 0.00) was more common in patients with low HBV DNA content. Both AST and GGT were significantly higher in patients with mutant pre-C and BCP loci than in those with wild-type loci (P < 0.05). PCR-reverse dot blot hybridization and MAMA-PCR for detection of mutations in the BCP and pre-C regions had good consistency, and the Kappa values obtained were 0.91 and 0.58, respectively.

CONCLUSION: HBeAg negative patients tend to have HBV pre-C mutations. However, these mutations do not cause increased DNA copies, but associate with damage of liver function.

Keywords: Basic core promoter region, Pre-core region, Liver injury, Reverse dot blot hybridization, Mismatch amplification mutation assay

Core tip: There is no exact evidence about the frequency of mutations in hepatitis B virus (HBV) pre-C and basic core promoter (BCP) regions of HBV in Shanxi Province and the correlation between mutations and disease-related indicators. Here, we found that the frequency of pre-C mutations was higher in hepatitis B e antigen (HBeAg) negative patients, and liver function parameters AST and GGT in the mutation group were higher than those in the wild-type group; however, DNA replication did not increase in the presence of HBV pre-C and BCP mutations. Taken together, HBeAg-negative patients tend to have HBV pre-C mutation. However, these mutations do not cause increased DNA copies, but associate with liver function damage.