AISF-SIMIT practice guidance on treatment of hepatitis d virus (HDV): A 2025 update.

Chronic hepatitis Delta virus (HDV) infection represents the most severe form of viral hepatitis, characterized by accelerated progression to cirrhosis, end-stage liver disease, and hepatocellular carcinoma. For decades, Pegylated Interferon (PegIFNα) has been the only therapeutic option, with limited efficacy and poor tolerability. The approval of the HBV/HDV entry inhibitor Bulevirtide marked a turning point, by providing the first anti-HDV specific antiviral drug. This position paper, developed jointly by the Italian Association for the Study of the Liver (AISF) and the Italian Society of Infectious and Tropical Diseases (SIMIT), updates prior national guidance by providing practical recommendations for diagnosis, staging, and treatment of chronic HDV infection.