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World J Gastroenterol. Jun 28, 2014; 20(24): 7686-7695
Published online Jun 28, 2014. doi: 10.3748/wjg.v20.i24.7686
Serum hepatitis B surface antigen levels predict treatment response to nucleos(t)ide analogues
Chien-Hung Chen, Yi-Chun Chiu, Sheng-Nan Lu, Chuan-Mo Lee, Jing-Houng Wang, Tsung-Hui Hu, Chao-Hung Hung
Chien-Hung Chen, Yi-Chun Chiu, Sheng-Nan Lu, Chuan-Mo Lee, Jing-Houng Wang, Tsung-Hui Hu, Chao-Hung Hung, Division of Hepato-Gastroenterology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, Kaohsiung 833, Taiwan
Author contributions: Chen CH performed the literature review and wrote the paper; Chiu YC, Lu SN, Lee CM, Wang JH and Hu TH contributed to acquisition of data; and Hung CH performed the critical revision.
Correspondence to: Chao-Hung Hung, MD, Division of Hepato-Gastroenterology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, 123 Ta Pei Road, Kaohsiung 833, Taiwan. chh4366@yahoo.com.tw
Telephone: +886-7-7317123 Fax: +886-7-7318762
Received: October 24, 2013
Revised: January 1, 2014
Accepted: May 23, 2014
Published online: June 28, 2014
Abstract

Quantification of hepatitis B surface antigen (HBsAg) has been suggested to be helpful in the management of chronic hepatitis B (CHB) patients. Nucleos(t)ide analogs (NAs) are the therapy of choice for CHB and are used in the majority of CHB patients. NAs are able to induce hepatitis B virus (HBV) viral suppression, normalization of alanine aminotransferase (ALT) levels, and improvement in liver histology. Automated quantitative assays for serum HBsAg have recently become available, facilitating standardized quantification of serum HBsAg. This has led to increased interest in the clinical application of quantitative serum HBsAg for predicting therapeutic response to NAs. Recent studies have shown that a decline in serum HBsAg levels in patients receiving peginterferon may signal successful induction of immune control over HBV, and can therefore be used to predict therapeutic response. NA treatment typically induces a less rapid decline in HBsAg than interferon treatment; it has been estimated that full HBsAg clearance can require decades of NA treatment. However, a rapid HBsAg decline during NA therapy may identify patients who will show clearance of HBsAg. Currently, there is no consensus on the clinical utility of serum HBsAg monitoring for evaluating patient responses to NA therapy. This review focuses on recent findings regarding the potential application of HBsAg quantification in the management of CHB patients receiving NA therapy.

Keywords: Alanine aminotransferase, Hepatitis B virus, Hepatitis B surface antigen, Nucleos(t)ide analogs, Virological response

Core tip: Patients receiving nucleos(t)ide analog (NA) treatment typically exhibit slow declines in serum hepatitis B surface antigen (HBsAg), with many patients requiring decades of treatment to achieve HBsAg clearance. However, a low baseline HBsAg level or a rapid reduction in HBsAg during NA therapy may identify patients who will show HBsAg clearance, and predict virological response or hepatitis B e antigen (HBeAg) loss/seroconversion in HBeAg-positive patients. Viral breakthrough due to drug resistance can increase HBsAg titers. Among Asian patients, HBsAg levels of < 100-200 IU/mL at the end of treatment may predict lower risk of hepatitis B virus relapse and cessation of treatment can be considered in HBeAg-negative patients.