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

• Main Authors: Adaliany Cecília da Silva Souza, Giórgia de Souza Marasca, Nélson Alexandre Kretzmann-Filho, Aline Dall-Bello, Dimas Alexandre Kliemann, Cristiane Valle Tovo, Ana Beatriz Gorini da Veiga
• Format: Article
• Language: English
• Published: Elsevier 2017-09-01
• Series: Brazilian Journal of Infectious Diseases
• Online Access: http://www.sciencedirect.com/science/article/pii/S1413867017300582

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. Keywords: Hepatitis B, HBV, A1762T/G1764A mutation