Hepatitis D revival

Abstract

More than 30 years after Mario Rizzetto and colleagues described a new antigen in livers of HBsAg-positive patients called the ''delta antigen'', a reemerging interest in hepatitis delta is currently observed. The state-of-the art on basic and clinical research on hepatitis delta was presented during a monothematic conference organized by the European Association for the Study of the Liver (EASL) in September 2010. Hepatitis delta is caused by infection with the hepatitis D virus (HDV) which requires presence of HBsAg for complete replication and transmission. Recent data confirmed the severe long-term course of HDV infection with high rates of hepatic decompensation while controversial data on the risk for the development of hepatocellular carcinoma were reported. Pegylated interferon alpha can lead to sustained HDV RNA elimination in about one quarter of patients while HBV polymerase inhibitors are ineffective against HDV. Novel treatment options include prenylation inhibitors and HBV entry inhibitors which are currently in early clinical development.

Mathematical models of the interrelated dynamics of hepatitis D and B

“…While HDV is capable of copying its genome in great numbers in infected hepatocytes, it requires the hepatitis B surface antigen (HBsAg) in order to create new free virus particles [1,2]. Thus, in order for HDV to successfully complete its replication cycle, a hepatocyte must be coinfected with HBV and HDV.…”

“…There is currently no effective treatment for chronically infected patients, and it is unclear why the outcomes for patients with HDV are so much worse than those for patients with HBV alone [1,5]. Further, the measured levels of HBV and HDV can exhibit a wide range of dynamic behaviors in different patients, including synchronized and alternating oscillations [3].…”

Molecular and clinical aspects of hepatitis D virus infections

“…To cure patients, long-term IFN treatment is required for undetectable HDV RNA and further treatment is required for HBsAg loss [67] . During therapy, monitoring of HDV RNA and HBsAg might help in the surveillance of therapy, although HDV RNA does not correlate with activity or stage of liver disease [68] . Overall, more long-term data as well as a better understanding of the viral life cycle and HDV/HBV interactions are needed for an efficient HDV treatment.…”

Study on seroprevalence of hepatitis delta in a regional hospital in western Turkey

“…Genotype I is the most prevalent. This genotype is commonly detected in Turkey, Greece, Italy, and various African countries [6]. HBV is essential for HDV replication.…”

“…These two clinical situations have different prognoses. The chronicity of coinfection is 2% to 7%, while the chronicity of superinfection is 70% to 90% [1,3,5,6].…”