Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Aug 28, 2019; 25(32): 4580-4597
Published online Aug 28, 2019. doi: 10.3748/wjg.v25.i32.4580
Chronic hepatitis delta: A state-of-the-art review and new therapies
Christy Gilman, Theo Heller, Christopher Koh
Christy Gilman, Theo Heller, Christopher Koh, Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, United States
Author contributions: All authors contributed equally to this manuscript in regard to design, literature review, analysis, revision and approval of the final version.
Conflict-of-interest statement: The authors have no conflict of interest to report.
Open-Access: This 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 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:
Corresponding author: Christopher Koh, FAASLD,FACP,MD, Attending Doctor, Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 10 Center Drive, Building 10, Room 9B-16, MSC 1800, Bethesda, MD 20892, United States.
Telephone: +1-301-4356121 Fax: +1-301-4020491
Received: May 21, 2019
Peer-review started: May 21, 2019
First decision: June 9, 2019
Revised: July 3, 2019
Accepted: July 19, 2019
Article in press: July 19, 2019
Published online: August 28, 2019

Chronic delta hepatitis is the most severe form of viral hepatitis affecting nearly 65 million people worldwide. Individuals with this devastating illness are at higher risk for developing cirrhosis and hepatocellular carcinoma. Delta virus is a defective RNA virus that requires hepatitis B surface antigen for propagation in humans. Infection can occur in the form of a co-infection with hepatitis B, which can be self-limiting, vs superinfection in a patient with established hepatitis B infection, which often leads to chronicity in majority of cases. Current noninvasive tools to assess for advanced liver disease have limited utility in delta hepatitis. Guidelines recommend treatment with pegylated interferon, but this is limited to patients with compensated disease and is efficacious in about 30% of those treated. Due to limited treatment options, novel agents are being investigated and include entry, assembly and export inhibitors of viral particles in addition to stimulators of the host immune response. Future clinical trials should take into consideration the interaction of hepatitis B and hepatitis D as suppression of one virus can lead to the activation of the other. Also, surrogate markers of treatment efficacy have been proposed.

Keywords: Hepatitis delta, Epidemiology, Treatment

Core tip: Delta hepatitis is a progressive disease affecting millions worldwide. Current treatment options have limited efficacy. This review focuses on the history of interferon therapy, novel therapies that have been developed and future treatment options for a possible functional cure.