Hepatitis D virus (HDV)

Hepatitis D virus (HDV) is a unique human pathogen and the smallest known animal virus, characterized by a circular, single-stranded RNA genome and the hepatitis delta antigen (HDAg) (NIH, 2023). It is a satellite virus that is obligatorily dependent on the Hepatitis B virus (HBV) for its envelope proteins, which are necessary for virion assembly and entry into host hepatocytes via the sodium-taurocholate cotransporting polypeptide (NTCP) receptor (WHO, 2023). HDV infection, which occurs either as a co-infection with HBV or a superinfection in chronic HBV carriers, leads to the most severe form of chronic viral hepatitis, rapidly progressing to cirrhosis and increasing the risk of hepatocellular carcinoma (PubMed, PMID: 33531136). Therapeutic strategies against HDV focus on blocking viral entry by targeting the NTCP receptor or inhibiting the post-translational modification (prenylation) of the large delta antigen required for viral packaging (EMA, 2020). Current clinical management involves entry inhibitors like bulevirtide and investigational farnesyltransferase inhibitors like lonafarnib, alongside pegylated interferon-alpha.

Other names

Hepatitis delta virusDelta virusHDV

Inhibition of viral entry via NTCP receptor binding, inhibition of large delta antigen prenylation via farnesyltransferase inhibition, and immunomodulation through interferon signaling.