HBsAg Loss as a Treatment Endpoint for Chronic HBV Infection: HBV Cure
by Maryam Moini
1 and Scott Fung
2,*
1
Department of Medicine, University of Ottawa, Ottawa, ON K1Y 4E9, Canada
2
Department of Medicine, University of Toronto, Toronto, ON M5G 2C4, Canada
*
Author to whom correspondence should be addressed.
Academic Editor: Carla S. Coffin
Viruses 2022, 14(4), 657; https://doi.org/10.3390/v14040657
Received: 7 February 2022 / Revised: 1 March 2022 / Accepted: 10 March 2022 / Published: 22 March 2022
(This article belongs to the Special Issue Recent Advances in Management of Hepatitis B and towards Achieving a HBV Cure)
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Abstract
Despite the availability of effective vaccines and antiviral therapy over the past two to three decades, chronic hepatitis B virus (HBV) infection remains a major global health threat as a leading cause of cirrhosis and liver cancer. Functional HBV cure defined as hepatitis B surface antigen (HBsAg) loss and undetectable serum HBV DNA is associated with improved clinical outcomes in patients with chronic HBV infection. However, spontaneous loss of HBsAg is rare and occurs in only 1% of all HBsAg-positive individuals annually. Furthermore, the rate of functional cure with currently available antiviral therapy is even lower, <1% patients on treatment per year. Nonetheless, HBsAg loss has become the new target or therapeutic endpoint for antiviral treatment. Recently, there has been much excitement surrounding the development of novel antiviral agents such as small interfering RNA (siRNA), core assembly modulators (CAMs), nucleic acid polymers (NAPs) among others, which may be used in combination with nucleos(t)ide analogs and possibly immunomodulatory therapies to achieve functional cure in a significant proportion of patients with chronic hepatitis B. Novel assays with improved sensitivity for detection of very low levels of HBsAg and to determine the source of HBsAg production will also be required to measure efficacy of newer antiviral treatments for HBV cure. In this narrative review, we will define HBV cure, discuss various sources of HBsAg production, evaluate rates of HBsAg loss with current and future antiviral agents, review clinical factors associated with spontaneous HBsAg loss, and explore clinical implications of functional cure. View Full-Text
Keywords: hepatitis B virus (HBV); HBV cure; hepatitis B surface antigen (HBsAg); antiviral therapy 作者: StephenW 时间: 2022-4-23 20:30