학술논문
A phylogenetic study of hepatitis B virus in chronically infected Brazilian patients of Western and Asian descent.
Document Type
Academic Journal
Author
Clemente CM; Carrilho FJ; Pinho JR; Ono-Nita SK; Silva LC; Moreira RC; Lemos MF; de Carvalho Mello IM; Clemente, Cintia Mendes; Carrilho, Flair José; Pinho, João Renato Rebello; Ono-Nita, Suzane Kioko; Da Silva, Luiz Caetano; Moreira, Regina Célia; Lemos, Marcílio Figueiredo; de Carvalho Mello, Isabel Maria Vicente Guedes
Source
Subject
Language
English
ISSN
0944-1174
Abstract
Background: Hepatitis B virus (HBV) causes one of the most important chronic viral infections worldwide. HBV is classified into eight genotypes whose epidemiology varies geographically. In Brazil, genotypes A, D, and F are more frequent, while in East Asia, genotypes B and C predominate. Several studies showed that immigrants retain the HBV infection pattern of their ancestral country.Purpose: To identify HBV genotypes infecting chronic carriers in Brazilian families of Western and Asian descent by Hepatitis B surface antigen gene sequencing and analyze the route of viral transmission by phylogenetic analysis of viral sequences.Methods: Eighty-seven people chronically infected with HBV were separated into two groups: Western descent (27) and Asian descent (60). Surface and pre-core/core genes were amplified from serum HBV-DNA and sequences were subjected to phylogenetic analysis.Results: HBV genotype A was found in 74% of Western subjects, while genotype C was found in 94% of Asian patients. Thirty-eight percent of Western families were infected with HBV with similar pre-core/core sequences, while only 25% of Asian families showed similarity in these sequences.Conclusions: Phylogenetical analysis of pre-core/core HBV gene suggested intra-familial transmission of HBV in 38% of Western families and 25% of Asian families. Analysis of HBsAg gene sequences helped to define the HBV genotype but did not allow inferring route of transmission as its sequences showed a smaller phylogenetic signal than pre-core/core sequences. Chronic HBV carriers of Asian descent born in or living in Brazil were infected with the same HBV genotype predominant in their ancestral country.