| [ Summary ] |
Hepatitis B virus (HBV) infection is a major health problem. Hepatitis B is endemic, especially in East Asia, including Japan. Chronic HBV infection can lead to severe chronic liver disease, namely cirrhosis or hepatocellular carcinoma (HCC). Recently, the HBV genotype has been suggested to correlate with differences in the clinical features of chronic HBV infection. ln East Asia, where genotypes B and C are the predominant HBV strains, genotype C is closely associated with the development of HCC and genotype B is associated with better prognoses. In northern Taiwan, however, genotype B is associated with the development of HCC in young non-cirrhotic patlents, in contrast to genotype B in Japan and China. Furthermore, HCC has been reported in association with basal core promoter (BCP) mutations (T 1762/A 1764). In a study from Hong Kong, by multiple logistic regression analysis, the only independent factor associated with HCC was BCP mutations, but genotype C HBV was not a significant factor. This result suggests that an association between HCC and genotype C is probably not genuine but is due to a high percentage of BCP mutations in patlents with genotype C. The genotype B can be devided into two subtypes [Ba (a for Asia) and Bj (j for Japan)] and the epidemiological and virological differences between these have been reported. However, these differences cannot explain the variable clinical outcomes of patients with genotype B HBV infection, at least in Taiwan. Further virological, environmental, and genetic studies are necessary. |