Hepatitis delta virus (HDV) is a unique defective RNA virus that requires the helper function of hepatitis B virus (HBV), which provides the essential coat protein for virion assembly and propagation. It is the smallest animal virus and the only one to possess a circular RNA genome, as seen in plant viruses. HDV has evolved into three major genotypes that differ in their geographic distribution...

Hepatitis delta virus (HDV) contains two types of hepatitis delta antigens (HDAg) in the virion. The small form (S-HDAg) is required for HDV RNA replication, whereas the large form (L-HDAg) potently inhibits it by a dominant-negative inhibitory mechanism. The sequential appearance of these two forms in the infected cells regulates HDV RNA synthesis during the viral life cycle. However, the pres...

BACKGROUNDS AND AIMS Hepatitis Delta Virus (HDV) is a defective ssRNA virus requiring the provision of hepatitis B virus (HBV) for packaging of new HDV virions. Since the epidemiological features of HDV in this part of Iran seem to be unknown, the aim of this research was to determine the seroprevalence of HDV of hepatitis B surface antigen positive (HBsAg+) in blood donors, injecting drug user...

Various domains of hepatitis B surface antigen (HBsAg) are essential for the assembly and secretion of hepatitis D virus (HDV). This study investigated the influences of the levels and sequences of HBsAg of naturally occurring HBV variants on the assembly and secretion of HDV. Six hepatitis B virus (HBV)-producing plasmids (three genotype B and three genotype C) and six HBsAg expression plasmid...

CONTEXT Hepatitis delta virus (HDV) leads to the most severe form of chronic viral hepatitis. OBJECTIVES To determine the prevalence of HDV and create pooled estimations of possible risk factors, a systematic review was conducted to collect all epidemiological studies on HDV among chronic hepatitis B patients in Iran. DATA SOURCES In this systematic review, databases such as PubMed, Embase,...

Hepatitis delta virus (HDV) contains a viroid-like circular RNA that is presumed to replicate via a rolling circle replication mechanism mediated by cellular RNA polymerases. However, the exact mechanism of rolling circle replication for HDV RNA and viroids is not clear. Using our recently described cDNA-free transfection system (L. E. Modahl and M. M. Lai, J. Virol. 72:5449-5456, 1998), we hav...

OBJECTIVE We evaluated the influence of hepatitis B virus (HBV) genotype on the course of disease in patients coinfected with HBV and hepatitis delta virus (HDV). METHODS We evaluated HBV genotypes in 190 patients, 140 of whom had chronic HBV monoinfection and 50 of whom had chronic HBV-HDV coinfection. Real-time polymerase chain reactions for the amplification of HBV DNA and HDV RNA were dev...

Hepatitis delta virus (HDV) is composed of four specific components. The first component is envelope protein which contains hepatitis B surface antigens. The second and third components are nucleocapsid proteins, referred to as small and large hepatitis delta antigens (HDAgs). The final component is a single-stranded circular RNA molecule known as the viral genome. In order to study the mechani...

BACKGROUND Approximately 5% of hepatitis B virus (HBV) carriers are coinfected with hepatitis D virus (HDV). HBV/HDV coinfection is a major cause of cirrhosis and end stage liver disease in chronic HBsAg carriers. The only approved therapy for chronic hepatitis delta is interferon alpha (IFN α) in either pegylated or conventional forms. Although higher doses and longer durations of IFN α therap...

Hepatitis delta antigen (HDAg), the only protein encoded by the hepatitis delta virus (HDV), binds specifically genomic and antigenomic strands of the HDV RNA. In a previous study, three recombinant HDAg subdomains were synthesized, covering residues 11 to 78, 79 to 163 and 164 to 212, and only the middle domain was shown to be responsible for the binding to HDV RNA. To investigate HDAg sequenc...