Identification of hepatitis B virus A1762T/G1764A double mutant strain in patients in Southern Brazil

• Main Author: Silva Souza,Adaliany Cecília da
• Publication Date: 2017
• Other Authors: Souza Marasca,Giórgia de, Kretzmann-Filho,Nélson Alexandre, Dall-Bello,Aline, Kliemann,Dimas Alexandre, Tovo,Cristiane Valle, Veiga,Ana Beatriz Gorini da
• Format: Article
• Language: eng
• Source: Brazilian Journal of Infectious Diseases
• Download full: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1413-86702017000500525
• topic: Hepatitis B; HBV; A1762T/G1764A mutation

Abstract Infection by hepatitis B virus (HBV) is a worldwide public health problem. Chronic HBV infection with high viral replication may lead to cirrhosis and/or hepatocellular carcinoma. Mutant HBV strains, such as the HBV A1762T/G1764A double mutant, have been associated with poor prognosis and higher risk of the patient for developing cirrhosis and/or hepatocellular carcinoma. This study analyzed the presence of the HBV A1762T/G1764A double mutant in patients with chronic HBV and its association with clinical parameters such as viral load, aminotransferases, and HBV antigens. A total of 49 patients with chronic hepatitis B were included in the study, and the HBV A1762T/G1764A double mutant strain was detected in four samples (8.16%) by polymerase chain reaction followed by restriction fragment length analysis (PCR-RFLP). The viral load was not significantly different between patients with or without the double mutant strain (p = 0.43). On the other hand, carriers of the HBV A1762T/G1764A double mutant had higher levels of ALT (p = 0.0028), while AST levels did not differ between groups (p = 0.051). In this study, 75% of the samples with the HBV A1762T/G1764A double mutation were HBeAg negative and anti-HBe positive, reflecting seroconversion even though they still displayed high viral loads. Our study has shown that the HBV A1762T/G1764A double mutant strain circulates in Brazilian patients, and is associated with elevated levels of ALT and HBeAg seroconversion.