Yang SS, Fu F, Xuan QK, Zhang ZX, Li ZJ, Li GB, Yu XY. Hepatitis B surface antigen-negative but hepatitis B envelope antigen-positive false occult hepatitis B virus infection: A case report. World J Hepatol 2024; 16(10): 1199-1207 [PMID: 39474578 DOI: 10.4254/wjh.v16.i10.1199]
Corresponding Author of This Article
Xiao-Yu Yu, PhD, Associate Chief Technician, Department of Laboratory Medicine, Shanghai East Hospital, Tongji University School of Medicine, No. 1800 Yuntai Road, Pudong District, Shanghai 200123, China. flyyuxx@163.com
Research Domain of This Article
Virology
Article-Type of This Article
Case Report
Open-Access Policy of This Article
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/
Shu-Sheng Yang, Qian-Kun Xuan, Zhi-Jun Li, Guang-Bo Li, Xiao-Yu Yu, Department of Laboratory Medicine, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200123, China
Fei Fu, Zhou-Xiang Zhang, Department of Obstetrics and Gynecology, Shanghai East Hospital, Tongji University School of Medicine, Shanghai 200123, China
Co-first authors: Shu-Sheng Yang and Fei Fu.
Co-corresponding authors: Guang-Bo Li and Xiao-Yu Yu.
Author contributions: Yang SS, Li GB, and Yu XY contributed to conceptualization and methodology; Fu F contributed to data curation and writing the original draft; Xuan QK, Zhang ZX, and Li ZJ contributed to data collection and investigation; Fu F and Yu XY contributed to manuscript writing, reviewing, and editing.
Supported bythe Shanghai Municipal Commission of Health and Family Planning, No. PKJ2018-Y05.
Informed consent statement: Written informed consent was obtained from the patient for the publication of this case report.
Conflict-of-interest statement: The authors declare that they have no conflict of interest to disclose.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
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: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Xiao-Yu Yu, PhD, Associate Chief Technician, Department of Laboratory Medicine, Shanghai East Hospital, Tongji University School of Medicine, No. 1800 Yuntai Road, Pudong District, Shanghai 200123, China. flyyuxx@163.com
Received: March 9, 2024 Revised: August 13, 2024 Accepted: September 14, 2024 Published online: October 27, 2024 Processing time: 225 Days and 11.1 Hours
Abstract
BACKGROUND
Occult hepatitis B infection (OBI) is characterized by the detection of hepatitis B virus (HBV) DNA in serum (usually HBV DNA < 200 IU/mL) or the liver but negativity for hepatitis B surface antigen (HBsAg). The diagnosis of OBI relies on the sensitivity of assays used in the detection of HBV DNA and HBsAg. HBsAg assays with inadequate sensitivity or inability to detect HBV S variants may lead to misdiagnosis of OBI in people with overt HBV infection.
CASE SUMMARY
We report a HBsAg-negative but hepatitis B envelope antigen-positive patient who had a significant HBV DNA level. The patient was initially diagnosed as having OBI. However, sequence analysis revealed a unique insertion of amino acid residues at positions 120-124 in the S protein, which affects the formation of a disulfide bond that is associated with the formation of a loop. It is well known that there is an overlap between the S protein and Pol protein. We found that this new insertion site occurred in polymerase/reverse transcriptase domain, indicating that this insertion might be involved in HBV pathogenicity. The patient was finally diagnosed with a false OBI.
CONCLUSION
An insertion of amino acid residues at positions 120-124 of the S protein affects the formation of immunodominant epitopes and results in negative HBsAg levels.
Core Tip: We report a hepatitis B surface antigen-negative but hepatitis B envelope antigen-positive patient who had a significant hepatitis B virus (HBV) DNA level. The patient was initially diagnosed as having OBI. However, sequence analysis revealed a unique insertion of amino acid residues at positions 120-124 in the S protein, which affects the formation of a disulfide bond that is associated with the formation of a loop. It is well known that there is an overlap between the S protein and Pol protein. We found that this new insertion site occurred in polymerase/reverse transcriptase domain, indicating that this insertion might be involved in HBV pathogenicity. The patient was finally diagnosed with a false OBI.
