Anti-HBV drug resistant mutations in acute symptomatic Hep B in the United States

The latest issue of the Journal of Hepatology evaluates anti-HBV drug resistant mutations among patients with acute symptomatic Hepatitis B in the United States.

Reported HBV drug resistance mutations among previously untreated patients with chronic hepatitis B are variable.

Whether resistant HBV strains are transmitted in the acute setting is uncertain.

Dr Dwayne Baxa and colleagues documented the presence of antiviral resistance mutations in patients with acute HBV infection.

Acuted Hepatitis B infection was defined by HBsAg/IgM anti-HBc positivity, ALT>10X the upper limit of normal and compatible clinical history.

The doctors noted that the TRUGENE HBV kit was used to perform genotyping and direct sequencing of the viral polymerase.

INNO-LiPA HBV DRv2 and DRv3 were used to detect antiviral resistance mutations.

The research team assessed that clonal sequencing was conducted on selected specimens.

The team evaluated 23 patients.

Clonal sequencing showed rtA181T mutations at an overall frequency of 1.5%

Journal of Hepatology

The researchers reported that the mean peak ALT was 1554.2IU/L and mean peak total serum bilirubin was 12mg/dl.

The HBV DNA median viral load was about 5 log10IU/ml.

The doctors noted that 19 patients were genotype A, and 1 each were genotype C, D, E and G.

HBV drug resistance mutations were not detected by direct sequencing or INNO-LiPA.

Clonal sequencing was conducted on 192 clones isolated from 3 patients and showed rtA181T, rtM250V and rtS202G mutations at an overall frequency of 1.5%, 1.4%, and 1.7% respectively.

Dr Baxa's team concluded, "We detected adefovir/lamivudine and entecavir relevant mutations in a minor population of viral clones by clonal sequencing only."

"The clinical significance of these mutations is uncertain and may represent small populations of quasi-species vs transmission of drug resistant strains."