title: Update on hepatitis B virus infection.
abstract: Chronic infection with hepatitis B virus (HBV) leads to the development of hepatocellular carcinoma and/or chronic liver failure. Despite extensive research, the immunopathogenesis is not completely understood. Viral persistence and clinical outcomes following HBV infection depend on viral factors and host factors; including genetic factors that determine a host's immune mechanisms. The primary goal of chronic hepatitis B (CHB) treatment is to eradicate HBV or to at least maintain suppression of HBV replication. Despite recent advances in anti-viral agents for chronic HBV infection, complete eradication of the virus has been difficult to achieve. Agents for the treatment of CHB are divided mainly into two groups: immunomodulating agents and antiviral nucleos(t)ide analogues (NAs). Although NAs are safe, effective and easily administered orally, their long-term use poses the risk of drug resistance. Currently, international evidence-based guidelines have been developed to support physicians in managing CHB patients. However, treatment of patients with drug resistance is still challenging, as only a few classes of anti-HBV drugs are available and cross-resistance between drugs can occur. In addition, as the currently available genotypic test for detection of drug resistance still has limitations in identifying the different substitutions present in the same viral genome, the development of a new virologic test to overcome this limitation is necessary. Among the predictive factors associated with response to pegylated interferon (PEG-IFN) therapy, hepatitis B surface antigen quantification is considered to be a surrogate marker for monitoring response to PEG-IFN. Current practice guidelines stress the importance of profound and durable HBV viral suppression in the treatment of CHB patients. To this end, it is essential to choose a potent antiviral drug with a low risk of resistance for initial treatment of CHB to achieve sustained virological response. This review highlights recent advances in the understanding of the immunopathogenesis of HBV and currently available and developing treatment strategies against HBV infection.
authors.affiliation: Chan Ran You, Sung Won Lee, Jeong Won Jang, Seung Kew Yoon, Division of Hepatology, Department of Internal Medicine, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul 137-701, South Korea.
authors.forename: Chan Ran
authors.initials: CR
authors.lastname: You
authors.affiliation: Chan Ran You, Sung Won Lee, Jeong Won Jang, Seung Kew Yoon, Division of Hepatology, Department of Internal Medicine, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul 137-701, South Korea.
authors.forename: Sung Won
authors.initials: SW
authors.lastname: Lee
authors.affiliation: Chan Ran You, Sung Won Lee, Jeong Won Jang, Seung Kew Yoon, Division of Hepatology, Department of Internal Medicine, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul 137-701, South Korea.
authors.forename: Jeong Won
authors.initials: JW
authors.lastname: Jang
authors.affiliation: Chan Ran You, Sung Won Lee, Jeong Won Jang, Seung Kew Yoon, Division of Hepatology, Department of Internal Medicine, College of Medicine, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul 137-701, South Korea.
authors.forename: Seung Kew
authors.initials: SK
authors.lastname: Yoon
mesh_terms: D000998:Antiviral Agents / Q000009:adverse effects / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D004279:DNA, Viral / Q000097:blood; D024882:Drug Resistance, Viral / Q000235:genetics; D005838:Genotype; D006514:Hepatitis B Surface Antigens / Q000097:blood; D006513:Hepatitis B e Antigens / Q000097:blood; D006515:Hepatitis B virus / Q000187:drug effects* / Q000235:genetics / Q000276:immunology; D019694:Hepatitis B, Chronic / Q000175:diagnosis / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D011237:Predictive Value of Tests; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D019562:Viral Load; D014779:Virus Replication
chemical_list: D000998:Antiviral Agents; D015415:Biomarkers; D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens
keywords: Antiviral therapy; Chronic hepatitis B; Hepatitis B virus; Nucleos(t)ide analogue; Pegylated interferon