Hepatitis B viral genotypes: Clinical relevance and molecular characteristics
Journal
Journal of Gastroenterology and Hepatology (Australia)
Journal Volume
17
Journal Issue
6
Pages
643-650
Date Issued
2002
Author(s)
Abstract
Hepatitis B virus (HBV) infection is a global health problem and the clinical outcome of chronic HBV infection depends on the frequency and severity of hepatitis flares in the immune clearance phase. Currently, four subtypes and seven genotypes of HBV are identified and most have specific geographic distributions. The impact of HBV genotypes on the clinical outcome of chronic HBV infection has been partially clarified. In Taiwan, genotype C is associated with more severe liver disease and genotype B is associated with the development of hepatocellular carcinoma (HCC) in young non-cirrhotic patients. In contrast, genotype B has a relatively good prognosis in Japan and China and is rarely associated with the development of HCC. Similarly, genotype D is associated with more severe liver disease than genotype A in India and may predict occurrence of HCC in young patients. Although superinfection of HBV on top of hepatitis B carriers occurs in Taiwan, it is rarely associated with acute exacerbations. As to the response to antiviral treatment, genotypes C and D are associated with a lower response rate to interferon therapy compared with genotypes B and A. In addition, the subtype adw is reported to be associated with a higher risk of lamivudine resistance than ayw. In HBV subtype adw-infected HCC patients, genotype B responds better to embolization therapy and has a lower rate of HCC recurrence than genotype C. In summary, pathogenic and therapeutic differences do exist among HBV genotypes and determining the genotype in patients with chronic HBV infection would help gain further information for etiologic, clinical, virologic and anthropologic investigations. Further studies to clarify the molecular virological factors that contribute to these differences are awaited. ? 2002 Blackwell Publishing Asia Pty Ltd.
Subjects
Chronic hepatitis; Clinical outcome; Genomic variability; Genotype; Hepatitis B virus; Hepatocellular carcinoma; Liver cirrhosis; Molecular epidemiology; Subtype; Superinfection
SDGs
Other Subjects
antivirus agent; interferon; lamivudine; virus DNA; artificial embolism; cancer recurrence; disease severity; disease transmission; gene mutation; genotype; geographic distribution; hepatitis B; Hepatitis B virus; human; liver cell carcinoma; liver disease; prediction; priority journal; prognosis; promoter region; review; stop codon; superinfection; treatment outcome; virus genome; genetics; genotype; hepatitis B; Hepatitis B virus; immunology; liver cell carcinoma; liver cirrhosis; liver tumor; superinfection; virology; Carcinoma, Hepatocellular; DNA, Viral; Embolization, Therapeutic; Genotype; Hepatitis B; Hepatitis B virus; Humans; Liver Cirrhosis; Liver Neoplasms; Superinfection
Publisher
Blackwell Publishing
Type
review