Profile, spectrum and significance of HBV genotypes in chronic liver disease patients in the Indian Subcontinent

Background and Aim: Certain hepatitis B virus (HBV) genotypes have been alleged to be associated with the development of cirrhosis and hepatocellular carcinoma (HCC), and the response to interferon therapy in Taiwanese patients. We undertook to study the prevalence and significance of HBV genotypes in the Indian subcontinent. Methods: One hundred and thirty histopathologically proven chronic HBV-infected patients, including 52 incidentally detected asymptomatic hepatitis B surface antigen (HBsAg)-positive subjects (IDAHS) with chronic HBV infection (group I), 48 cirrhotics (group II) and 30 hepatocellular carcinoma (HCC; group III) patients were studied. Hepatitis B virus genotypes were determined by using restriction fragment length polymorphism, and direct sequencing of the s gene including the 'a' determinant region. Results: Only genotypes A (46%) and D (48%) were found in the chronic HBV-infected patients. A mixed infection with genotypes A and D was seen in 6% of patients. Genotype A was found in 42, 48 and 50%, and genotype D in 48, 50 and 47% of group I, II and III patients, respectively (P = NS). The patients who had mixed genotypes were significantly younger (P < 0.05). In group I (IDAHS) patients infected with genotype D, none had a histological activity index (HAI) of < four. Genotype D was significantly more common in group I patients with HAI > 4 as compared to genotype A (53 vs 32%, P < 0.05). Similarly, genotype D was associated with more severe liver diseases (61 vs 30%, P < 0.05). Genotype D was more prevalent in HCC patients of < 40 years of age, as compared to IDAHS (63 vs 44%, P = 0.06). Conclusions: (i) Hepatitis B virus genotypes A and D are prevalent in chronic liver disease patients of Indian origin; and (ii) HBV genotype D is associated with more severe diseases and may predict the occurrence of HCC in young patients