HDV
not annotated - annotated - LINNAEUS only
20962099
Replicative and transcriptional activities of hepatitis B virus in patients coinfected with hepatitis B and hepatitis delta virusesviruses.
Hepatitis B virus (HBV) and hepatitis delta virus (HDV) interplay was investigated by examining liver and serum samples from 21 coinfected and 22 HBV-monoinfected patients with chronic liver disease. Different real-time PCR assays were applied to evaluate intrahepatic amounts of HBV DNA, covalently closed circular DNA (cccDNA), pregenomic RNA (pgRNA), pre-S/S RNAs, and HDV RNA. Besides HBV DNA and HDV RNA levels, HBsAg concentrations in the sera were also determined. HDV-coinfected cases showed significantly lower median levels of serum HBV DNA (-5 log), intrahepatic relaxed-circular DNA (-2 log), and cccDNA (-2 log) than those of HBV-monoinfected cases. Interestingly, pgRNA and pre-S/S RNA amounts were significantly lower (both -1 log) in HDV-positive patients, whereas serum HBsAg concentrations were comparable between the two patient groups. Pre-S/S RNA and HBsAg amounts per cccDNA molecule were higher in HDV-positive patients (3-fold and 1 log, respectively), showing that HBV replication was reduced, whereas synthesis of envelope proteins was not specifically decreased. The ratios of cccDNA to intracellular total HBV DNA showed a larger proportion of cccDNA molecules in HDV-positive cases. For these patients, both intrahepatic and serum HDV RNA amounts were associated with cccDNA but not with HBsAg or HBV DNA levels. Finally, HBV genomes with large deletions in the basal core promoter/precore region were detected in 5/21 HDV-positive patients but in no HDV-negative patients and were associated with lower viremia levels. These findings provide significant information about the interference exerted by HDV on HBV replication and transcription activities in the human liver.
21511329
Hepatitis delta virus.
Hepatitis delta virus (HDV) is a small, defective RNA virus that can infect only individuals who have hepatitis B virus (HBV); worldwide more than 15 million people are co-infected. There are eight reported genotypes of HDV with unexplained variations in their geographical distribution and pathogenicity. The hepatitis D virion is composed of a coat of HBV envelope proteins surrounding the nucleocapsid, which consists of a single-stranded, circular RNA genome complexed with delta antigen, the viral protein. HDV is clinically important because although it suppresses HBV replication, it causes severe liver disease with rapid progression to cirrhosis and hepatic decompensation. The range of clinical presentation is wide, varying from mild disease to fulminant liver failure. The prevalence of HDV is declining in some endemic areas but increasing in northern and central Europe because of immigration. Treatment of HDV is with pegylated interferon alfa; however, response rates are poor. Increased understanding of the molecular virology of HDV will identify novel therapeutic targets for this most severe form of chronic viral hepatitis.