The Brazilian Journal of Infectious Diseases The Brazilian Journal of Infectious Diseases
Original article
Identification of hepatitis B virus A1762T/G1764A double mutant strain in patients in Southern Brazil
Adaliany Cecília da Silva Souzaa, Giórgia de Souza Marascaa, Nélson Alexandre Kretzmann-Filhoa, Aline Dall-Belloa, Dimas Alexandre Kliemanna,b, Cristiane Valle Tovoa,b, Ana Beatriz Gorini da Veigaa,,
a Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), Programa de Pos-Graduação em Medicina: Hepatologia, Porto Alegre, RS, Brazil
b Hospital Nossa Senhora da Conceição (HNSC), Porto Alegre, RS, Brazil
Received 18 January 2017, Accepted 11 May 2017

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.

Hepatitis B, HBV, A1762T/G1764A mutation