Current Management of HBV/HDV Coinfection and Future Perspectives

Abstract

The hepatitis delta virus (HDV) is the smallest virus known to infect humans. It depends on the helper function of the hepatitis B surface antigen (HBsAg), and HDV infection is therefore only possible in patients infected with hepatitis B. Worldwide, an estimated 10–20 million individuals are coinfected with HDV. Migration of patients from highly prevalent areas accounts for the majority of hepatitis delta cases in Europe and North America. Chronic hepatitis delta is the most severe form of viral hepatitis with accelerated fibrosis progression, more frequent development of liver cirrhosis, earlier hepatic decompensation, and reduced survival rates compared to HBV monoinfection. Currently, only pegylated interferon alfa can be used to treat HDV, leading to HDV RNA suppression in 25–47 % of cases. However, interferon alfa rarely induced cure of HDV infection as long-term relapses have been described in many patients. Currently, alternative treatment options like prenylation inhibitors and HBV entry inhibitors are tested in early clinical trials. Moreover, other novel compounds aiming to achieve serological cure of HBV infection would be of particular importance for hepatitis delta as HBsAg elimination would be the ultimate goal also for hepatitis delta. In this review, we summarize the current state of the art on the management of HDV infection and highlight some perspectives for novel therapies.