Hepatitis delta virus infection: molecular biology and treatment.

Hepatitis delta virus is a defective human infectious agent which causes severe hepatic damage in hepatitis B virus-infected patients. Although prophylactic steps and the development, in certain countries, of efficient vaccination programs against hepatitis B virus have led to a diminution of the incidence rate of this disease, hepatitis D is still an important health problem. Hepatitis D infection is therefore associated with a worse clinical evolution than hepatitis B infection alone. On the other hand, the different therapeutic strategies being assayed at present including the use of interferon, have shown to be inefficient in the treatment of this disease. In this article, different aspects of the molecular biology and natural history of the infection, specially focused on those unknown aspects of this virus, are discussed. Finally, we have included a revision of the current state of hepatitis D treatment, as well as a comment of the new experimental strategies, like the use of antisense probes and trans-ribozyme activities.