CaracterizaÃÃo genÃtica do vÃrus da hepatite B em Alagoas

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Hepatitis B virus (HBV) has been classified into eight genotypes (A to H), with distinct geographical distributions. The divergences between the genotypes have been defined arbitrarily, based on a difference of more than 8% in the virus genome sequence. Naturally variants are found in regions pre-S/S, pre-core/C and P. The mutation of the precore region (G1896A) is most frequently detected in genotypes B, C, D, E and F, in hepatitis B virus (HBV) infections, while mutations in the basal core promoter (BCP) region (1762T/1764A) have been described in all genotypes. The aim of this study was to investigate the genotypes and the presence of pre-core mutations G1896A and BCP A1762T and G1764A in HBV, analyzing, viral load, profile HBeAg / anti-HBe and serum levels of alanine aminotransferase (ALT) in patients with infections HBV. This was a descriptive cross-sectional study involving patients referred by the Reference Center on Viral Hepatitis of the State of Alagoas, Brazil, during the period September 2006 to April 2008. We selected 119 patients with HBsAg and anti-HBc positive, including 2.5% (3) had the diagnosis of acute hepatitis, 69.7% (83) of asymptomatic carriers and 27.8% (33) of chronic hepatitis. Blood samples were subjected to the procedures for extraction and amplification of the viral genome to the partial sequencing of the gene S and pre-core region. The HBV DNA was detected in 70.6% (84/119) of patients and the genotypes in 95.2% (80/84). The following genotypes were identified: genotype A in 92.5% (74/80), followed by genotype C in 5.0% (4/80) and 1.25% (1/80) for both genotypes D and F. In genotype A, the presence of thymine/cytosine at position 1858 was identified in 50% (13/26) of the sequences analyzed, the G1896A mutation in 3.8% (1/26) and the BCP mutations in 52.4% (11/21). The research showed that genotype A was predominant in Alagoas, Brazil, most of the infections had reduced viral load, normal serum concentration of ALT and serum-conversion of HBeAg to anti-HBe, characterizing the residual phase of chronic HBV infection. BCP mutations were detected equally in asymptomatic carriers and chronic hepatitis, independently the viral load and serum levels of ALT

ASSUNTO(S)

mutation in the core promoter hepatitis b virus genotypes genÃtipos vÃrus da hepatite b mutaÃÃo prÃ-core mutaÃÃo no promotor core medicina pre-core mutation

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