Hepatitis Delta Virus

  • Author: Mario Rizzetto, MD (More Info)
  • Editor In Chief: Stefan Zeuzem, MD
  • Last Reviewed: 6/1/18 (What's New)

Summary

Introduction

  • HDV is a unique human pathogen dependent for infection on the hepatitis B virus
    • Patients coinfected with HDV and HBV experience more severe liver disease, more rapid progression to cirrhosis, and are more likely to experience hepatic decompensation and death vs patients infected with HBV alone
  • The exact mechanism by which HDV causes these consequences is not yet fully understood, and treatment options for patients with HDV infection are limited

Virology

  • HDV is a unique RNA pathogen that replicates through a double rolling circle mechanism unknown in other animal viruses
  • HDV is dependent on HBV for infection and can thrive only in patients with HBsAg
    • The only function of HBV required from HDV is the HBsAg coat for morphogenesis
    • Infection with HDV is not correlated with the level of HBV DNA
  • HDV has no replicative function of its own; it is replicated by host machinery
  • HDV genome contains a ribozyme and encodes for 2 proteins, S-HDAg and L-HDAg
    • The ribozyme, an RNA segment of approximately 85 nucleotides that self-cleaves and self-ligates without the need of enzymatic functions, is critical to the life cycle of the virus[...

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