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Detection of Low Copy Number Integrated Viral DNA Formed by In Vitro Hepatitis B Infection
Published on: November 7, 2018
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Differences in sequences between HBV-relaxed circular DNA and covalently closed circular DNA
Magda Rybicka1, Anna Woziwodzka1, Tomasz Romanowski1
1Department of Molecular Diagnostics, Intercollegiate Faculty of Biotechnology, University of Gdansk and Medical University of Gdansk, Abrahama 58, Gdansk 80-307, Poland.
Emerging Microbes & Infections
|June 22, 2017
Summary
Hepatitis B virus (HBV) DNA sequences in serum and liver tissue show variations between relaxed circular DNA (RCDNA) and covalently closed circular DNA (cccDNA) forms. These genetic differences may influence treatment strategies for chronic HBV infection.
Area of Science:
- Virology
- Hepatology
- Molecular Biology
Background:
- The hepatitis B virus (HBV) genome exists as relaxed circular DNA (RCDNA) in serum and covalently closed circular DNA (cccDNA) in liver cells.
- Understanding sequence variations between these forms is crucial for managing chronic HBV infection.
Purpose of the Study:
- To investigate sequence differences between HBV RCDNA and cccDNA in paired serum and liver tissue samples.
- To analyze the impact of these sequence variations on HBV genetic regions and clinical parameters.
Main Methods:
- Paired serum and liver biopsy samples from 67 chronically infected patients were analyzed.
- Genotyping of RCDNA and cccDNA was performed using mass spectrometry.
- Mutations in HBV pol (P) and basal core promoter/pre-core (BCP/PC) regions were assessed.
Main Results:
- Significant differences were observed in BCP/PC and P sequences between RCDNA from liver and blood (39% and 16% of patients, respectively).
- Sequence variations were also found between RCDNA and cccDNA within the same liver specimen.
- HBV cccDNA BCP/PC sequence variations impacted virological and clinical parameters.
Conclusions:
- HBV RCDNA and cccDNA sequences exhibit differences within the same liver tissue.
- Further research is needed to determine if cccDNA acts as a mutation reservoir.
- These findings may inform therapeutic decisions for treatment-experienced patients.
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