Clinical relevance of the detection of hepatitis delta virus RNA in serum by RNA hybridization and polymerase chain reaction

Analysis on the clinical features of 507 HDV-infected patients

The objective of this study was to analyze the clinical feature of hepatitis delta virus (HDV)-infected patients and to discuss the pathological mechanism of hepatitis D. A total of 507 patients with hepatitis due to the infection of HDV were included. The incidence rates of various hepatitis subtypes, the sequelae, the clinical manifestation, the hepatic function, and the hepatic virus makers for all the 507 patients were analyzed statistically. A cohort of 213 patients with hepatitis B, who were also HDV free, served as the control. HDV infection significantly contributed to the increased incidence rate and mortality of severe hepatitis (SH) and cirrhosis (P < 0.01). HDV was also associated with higher incidence rates of hemorrhage in the gastrointestinal tract, abdominal ascites and hepatic encephalopathy, repetitive augmentation of alanine transaminase, and its enhanced magnitude (P < 0.01 or 0.05). The major liver function changes in patients with SH or chronic serious hepatitis was significant compared to the control (P < 0.01). Within the HDV(+) category, HBeAg(-) expression was significantly higher in the HBV DNA(-) group than the HBV DNA(+) group (P < 0.01). The expression of HDAg(+) HBeAg(-) in acute hepatitis, SH, and cirrhosis was significantly higher than that of HDAg(+) HBeAg(+) (P < 0.01 or P < 0.05). The HDV infection was closely associated with the development and prognosis of chronic serious hepatitis, SH, and cirrhosis. HDV infection could inhibit the HBV DNA replication or the HBcAg expression. The direct cytotoxicity of HDV might be the leading pathological factor in AH. HDV might play a major role in the deterioration and chronicization of HDV-co-infected hepatitis B and was responsible for the increased mortality of HBV/HDV patients.

Efficacy of peginterferon alpha-2b in chronic hepatitis delta: relevance of quantitative RT-PCR for follow-up

Hepatitis delta virus (HDV) can cause severe acute and chronic liver disease in patients infected by hepatitis B virus. Interferon alpha at high doses, although poorly efficient, is the only treatment reported to provide some benefit in chronic hepatitis delta. Pegylated interferon alpha (PEG-IFN) has not yet been evaluated. Treatment is usually monitored by the qualitative detection of HDV-RNA in serum. In this study, safety and efficacy of PEG-IFN were assessed in chronic hepatitis delta, and serum HDV-RNA kinetics were determined using quantitative RT-PCR. Fourteen patients with chronic hepatitis delta received subcutaneous PEG-IFN alpha-2b during 12 months (1.5 microg/kg per week). Serum HDV-RNA was quantified at initiation and during the course of therapy, and during the posttreatment follow-up period, which ranged from 6 to 42 months (median 16 months). PEG-IFN alpha-2b was well tolerated, inducing no serious adverse effect. Sustained biochemical response was obtained in 8 patients (57%). At the end of treatment, 8 patients (57%) had achieved virological response (undetectable HDV-RNA). Sustained virological response throughout the posttreatment follow-up period was observed in 6 patients (43%). HDV-RNA kinetics were predictive of the response: after 3 months of PEG-IFN, HDV-RNA levels were significantly lower in the responders than in the nonresponders group (P=.018). After 6 months of therapy, a negative HDV-RNA was predictive of sustained response (P=.021). In conclusion, this preliminary study indicates that PEG-IFN alpha-2b is safe and efficient for treatment of chronic hepatitis delta. The follow-up of HDV-RNA levels during therapy, which allows the differentiation of various profiles of virological responses, improves treatment monitoring.

Hepatitis delta virus: the molecular basis of laboratory diagnosis

Infection with hepatitis delta virus (HDV), a satellite virus of hepatitis B virus (HBV), is associated with severe and sometimes fulminant hepatitis. The traditional methods for the diagnosis of HDV infection, such as detection of serum anti-HD antibodies, are sufficient for the clinical diagnosis of delta infection. However, such techniques lack the sensitivity and specificity required to more accurately characterize the nature of HDV infection and to assess the efficacy of therapies. Recent improvements in molecular techniques, such as HDV RNA hybridization and RT-PCR, have provided increased diagnostic precision and a more thorough understanding of the natural course of HDV infection. These advances have enhanced the clinician's ability to accurately evaluate the stage of HDV infection, response to therapy, and occurrence of reinfection after orthotopic liver transplant. This review focuses on the recent advances in the understanding of the molecular biology of HDV and in the laboratory diagnosis of HDV infection.

Diagnostic value of anti-hepatitis D virus (HDV) antibodies revisited: a study of total and IgM anti-HDV compared with detection of HDV-RNA by polymerase chain reaction

A high serum titre (> or = 1000 or > or = 5000) of total antibody to hepatitis D virus (anti-HDV) and positive for immunoglobulin (Ig)M anti-HDV have been used to represent HDV replication, while reverse transcription-polymerase chain reaction (RT-PCR) is currently the most sensitive assay for detecting HDV viraemia. The aim of the present study was to re-evaluate the correlation of total anti-HDV and IgM anti-HDV with HDV viraemia based on RT-PCR and to assess the clinical significance of these markers in acute and chronic HDV superinfection. Chronic HDV infection was defined as positive HDV-RNA by RT-PCR for more than 6 months, while total anti-HDV titre was defined by serial dilution. Of 178 hepatitis B virus (HBV) carrier patients studied, 119 cases had been anti-HDV positive for more than 6 months. Two-thirds (79/119) were positive for HDV viraemia by RT-PCR. Only half the chronic HDV viraemic patients had a high titre (> or = 1000) of total anti-HDV, and there was only moderate agreement (kappa = 0.41) between total anti-HDV titre/IgM anti-HDV and HDV-RNA and chronic HDV viraemia. Based on cross-sectional and longitudinal follow-up analyses, serum total anti-HDV titres > or = 100 appeared to be an excellent cut-off titre (kappa = 0.91) in differentiating chronic from acute HDV infection among viraemic patients. In summary, IgM and a high titre total of anti-HDV are not good markers of HDV viraemia, but an anti-HDV titre of > or = 100 appears to be an excellent marker for the differentiation of acute from chronic HDV superinfection.

Review: hepatitis delta

The causative agent of hepatitis delta virus (HDV) is the most unusual of all causative agents for all hepatitis viruses. Current knowledge of the molecular biology of HDV strengthens its proposed classification within the satellites, a family of subviral agents, some of which are pathogens of higher plants. Hepatitis delta virus is the only virus in the satellite family known to infect animal species, with hepatitis D having affected more than 10 million people worldwide who are also infected with its helper virus, HBV. Recently, the world map for hepatitis D appears somewhat modified, with decreasing HDV prevalence in certain areas and some new foci of HDV endemicity. Despite changing HDV prevalence, hepatitis. D, particularly the chronic form, is still an important health problem worldwide in terms of morbidity and mortality (mainly due to chronic liver disease, including hepatocellular carcinoma). Molecular studies have greatly advanced our understanding of the life cycle of HDV and of the function of its proteins. The new molecular information is of clinical relevance, with implications for the pathogenesis of liver damage, the diagnosis of HDV infection, for the natural course of the disease and, potentially, for therapy. Sensitive assays for HDV-RNA by polymerase chain reaction and sequencing techniques have clarified the patterns of HDV transmission and have confirmed the existence of unusual clinical forms of the virus and their relationship to replicative levels and genotypes of HDV. Prevention and treatment of hepatitis D are still in their infancy. However, liver transplantation for delta cirrhosis has proven far more successful than in any other viral form of cirrhosis, with few reinfections of the grafted liver, and has given important information on HDV biology and the pathogenesis of liver damage.