Hepatitis B virus mutations associated with antiviral therapy

Area of Science:

• Virology
• Molecular Biology
• Genetics

Background:

• Hepatitis B virus (HBV) replication involves an error-prone reverse transcriptase, generating diverse quasispecies.
• Antiviral drug pressure selects for pre-existing HBV mutants, leading to dominant resistant strains.
• HBV's overlapping reading frames complicate mutation impact, as polymerase (Pol) gene mutations affect surface antigen (HBsAg).

Purpose of the Study:

• To analyze the emergence and characteristics of antiviral drug-resistant HBV mutants.
• To highlight the role of HBV genomic databases in monitoring mutations and aiding diagnostic development.
• To underscore the need for improved treatment strategies against HBV drug resistance.

Main Methods:

• Analysis of HBV genomic databases to identify mutation profiles under antiviral selection.
• Review of factors contributing to antiviral drug resistance emergence.
• Characterization of HBsAg mutations selected during antiviral treatment.

Main Results:

• HBV quasispecies harbor mutations, with drug resistance emerging under selective pressure.
• Pol gene mutations can impact HBsAg function due to overlapping reading frames.
• Genomic databases facilitate monitoring of HBV polymerase and envelope mutations.

Conclusions:

• Antiviral resistance in HBV is multifactorial, influenced by mutation frequency, target site mutability, drug pressure, replication dynamics, and fitness.
• Limited characterization of HBsAg mutations necessitates further investigation into their diagnostic and public health implications.
• Urgent development of improved treatment strategies is required to combat the rise of HBV drug-resistant mutants.