Format

Send to

Choose Destination
J Hepatol. 2017 Aug;67(2):246-254. doi: 10.1016/j.jhep.2017.03.027. Epub 2017 Apr 7.

Selection of the highly replicative and partially multidrug resistant rtS78T HBV polymerase mutation during TDF-ETV combination therapy.

Author information

1
Department of Medicine III, RWTH-University Hospital Aachen, Aachen, Germany; Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
2
Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
3
Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III, Madrid, Spain; Liver Unit, Vall d'Hebron Institute of Research (VHIR), Universitat Autònoma de Barcelona (UAB), Barcelona, Spain.
4
Medical Care Centre, Dr Stein and Colleagues, Mönchengladbach, Germany.
5
Roche Diagnostics SL, Sant Cugat del Vallès, Spain.
6
Department of Medicine III, RWTH-University Hospital Aachen, Aachen, Germany.
7
Department of Medicine III, RWTH-University Hospital Aachen, Aachen, Germany. Electronic address: frank.tacke@gmx.net.

Abstract

BACKGROUND & AIMS:

Patients chronically infected with the hepatitis B virus (HBV) and receiving long-term treatment with nucleoside or nucleotide analogues are at risk of selecting HBV strains with complex mutational patterns. We herein report two cases of HBV-infected patients with insufficient viral suppression, despite dual antiviral therapy with entecavir (ETV) and tenofovir (TDF). One patient died from aggressive hepatocellular carcinoma (HCC).

METHODS:

Serum samples from the two patients at different time points were analyzed using ultra-deep pyrosequencing analysis. HBV mutations were identified and transiently transfected into hepatoma cells in vitro using replication-competent HBV vectors, and functionally analyzed. We assessed replication efficacy, resistance to antivirals and potential impact on HBV secretion (viral particles, exosomes).

RESULTS:

Sequencing analyses revealed the selection of the rtS78T HBV polymerase mutation in both cases that simultaneously creates a premature stop codon at sC69 and thereby deletes almost the entire small HBV surface protein. One of the patients had an additional 261bp deletion in the preS1/S2 region. Functional analyses of the mutations in vitro revealed that the rtS78T/sC69∗ mutation, but not the preS1/S2 deletion, significantly enhanced viral replication and conferred reduced susceptibility to ETV and TDF. The sC69∗ mutation caused truncation of HBs protein, leading to impaired detection by commercial HBsAg assay, without causing intracellular HBsAg retention or affecting HBV secretion.

CONCLUSIONS:

The rtS78T/sC69∗ HBV mutation, associated with enhanced replication and insufficient response to antiviral treatment, may favor long-term persistence of these isolates. In addition to the increased production of HBV transcripts and the sustained secretion of viral particles in the absence of antigenic domains of S protein, this HBV mutation may predispose patients to carcinogenic effects.

LAY SUMMARY:

Long-term treatment with antiviral drugs carries the risk of selecting mutations in the hepatitis B virus (HBV). We herein report two cases of patients with insufficient response to dual tenofovir and entecavir therapy. Molecular analyses identified a distinct mutation, rtS78T/sC69∗, that abolishes HBsAg detection, enhances replication, sustains exosome-mediated virion secretion and decreases susceptibility to antivirals, thereby representing a potentially high-risk mutation for HBV-infected individuals.

KEYWORDS:

Carcinoma; Drug resistance; Exosomes; Hepatitis B surface antigens; Hepatitis B virus; Hepatocellular; Mutations

PMID:
28392234
PMCID:
PMC6016549
DOI:
10.1016/j.jhep.2017.03.027
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Elsevier Science Icon for PubMed Central
Loading ...
Support Center