Chronic Hepatitis D Virus Research Articles

Effects of Polymorphisms in Interferon λ 3 (Interleukin 28B) on Sustained Virologic Response to Therapy in Patients With Chronic Hepatitis D Virus Infection

We investigated the association between interferon λ 3 (IFNL3) genotype (also known as interleukin 28B) and response to IFNα therapy in patients with chronic hepatitis D virus (HDV) infection. We studied IFNL3 genotypes of 32 patients (19 men; median age, 42.5 y) with chronic HDV infection. Nineteen patients (59%) were treated with pegylated IFNα and 13 patients (41%) were treated with standard IFNα, for at least 12 months. Levels of HDV RNA were measured before the initiation of treatment and every 6 months thereafter; patients were followed up for a median time of 16 months (range, 6-164 mo) after treatment ended. We used real-time polymerase chain reaction to classify the IFNL3 polymorphism rs12979860 as CC, CT, or TT, and rs8099917 as TT, GT, or GG. A virologic response was defined as undetectable HDV RNA in serum, and a sustained virologic response (SVR) was defined as undetectable HDV RNA after cessation of treatment until the end of the follow-up period. We evaluated the association between IFNL3 polymorphism and treatment response using univariate and multivariate analyses. After treatment, a response was achieved in 16 patients (50%) and an SVR was achieved in 9 (28%). The percentages of patients with CC, CT, and TT at rs12979860 were 47%, 47%, and 6%, respectively; the percentages of patients with TT, GT, and GG at rs8099917 were 69%, 28%, and 3%, respectively. Rates of SVR were 27%, 27%, and 50% in patients with CC, CT, TT at rs12979860 (P = .78 for CC vs CT vs TT) and 36%, 11%, and 0% in patients with TT, GT, and GG at rs8099917 (P = .30 for TT vs GT vs GG). The IFNL3 polymorphisms rs12979860 and rs8099917 do not significantly affect responses of patients with chronic HDV infection to treatment with IFNα.

Treatment Options for Hepatitis Delta Virus Infection

The hepatitis D virus (HDV), the smallest virus known to infect man, causes the most severe form of chronic viral hepatitis, hepatitis delta. It is estimated that about 15 to 20 million people are suffering from chronic HDV infection. HDV is a defective satellite virus depending on the hepatitis B surface antigen (HBsAg) for transmission. Chronic hepatitis delta is associated with a rapid progression of liver fibrosis and a high prevalence of liver cirrhosis, even in younger patients. Immunization against hepatitis B virus (HBV) protects from HDV infection, but there is no specific vaccine against HDV available for HBsAg-positive individuals. Treatment options for hepatitis delta patients are limited. So far, only interferon-alpha has shown an antiviral efficacy against HDV. Recent trials showed sustained virological response rates concerning HDV in 25%-30% of patients treated with pegylated interferons. HDV is dominant over HBV in the majority of cases, but HBV DNA-positive subjects should be treated with HBV polymerase inhibitors. Combination therapy of pegylated interferon-alpha and adefovir showed a more pronounced HBsAg decline, but the exact role of combination therapies in hepatitis delta requires further investigation. Alternative future treatment strategies may include prenylation inhibitors and HBV entry inhibitors, which are in early clinical development.

A Population-Based Study of Hepatitis D Virus as Potential Risk Factor for Hepatocellular Carcinoma

Hepatitis D virus (HDV) is dependent on the presence of hepatitis B virus (HBV) for transmission and replication because of its inability to produce its own coat. It remains unclear whether HDV infection increases the risk of hepatocellular carcinoma. Using the Swedish Hospital Discharge Register and Outpatient Registry, we identified 9160 patients with chronic HBV infection between 1997 and 2008, of whom 327 had chronic HDV infection and 323 had acute HDV infection. Standardized incidence ratios (SIRs) were calculated for these patients compared with the general population. The risk of hepatocellular carcinoma was greatly increased in patients with HBV and HDV (SIR = 137.17, 95% confidence interval [CI] = 62.19 to 261.51). The risk of hepatocellular carcinoma among patients with HBV and HDV was increased (SIR = 6.11, 95% CI = 2.77 to 11.65) when patients with chronic HBV infection alone were used as the reference population. Similar results were observed for patients with chronic HDV infection (SIR = 99.26, 95% CI = 42.39 to 196.55). Our findings indicate that HDV is a strong risk factor for hepatocellular carcinoma.

Hepatitis D virus‐specific cytokine responses in patients with chronic hepatitis delta before and during interferon alfa‐treatment

Hepatitis delta is caused by infection with the hepatitis D virus (HDV) and is considered the most severe form of viral hepatitis. Treatment options for hepatitis delta are limited, with only 25% of patients responding to interferon (IFN)-alfa-based therapies. The role of the adaptive immune system in controlling HDV infection during spontaneous or treatment-induced viral clearance is not well understood. We studied HDV-specific cytokine production of peripheral blood mononuclear cells stimulated with HDV peptide pools as well as serum cytokine levels in well-characterized patients with chronic HDV infection before and during pegylated-interferon-alfa±adefovir therapy. Hepatitis D virus-specific interleukin (IL)-2, IFN-γ-, interferon-inducible protein-10 and IL-10-responses were detectable in 53%, 35%, 65% and 6% of hepatitis delta patients. HDV-specific IFN-γ responses tended to be more common in patients with low HDV viral loads. HDV-specific cytokine responses declined during pegylated (PEG)-IFNa therapy and patterns of changes were associated with the treatment response. Serum cytokine levels also showed distinct changes during PEG-IFNa treatment. We suggest that cellular HDV-specific immune responses contribute to the control of HDV infection and that cytokine responses may indicate response to type-I-IFN-based antiviral therapy of hepatitis delta.

Rapid early HDV RNA decline in the peripheral blood but prolonged intrahepatic hepatitis delta antigen persistence after liver transplantation

Chronic HDV infection is an inflammatory liver disease and liver transplantation (LTX) remains the only curative treatment option for most patients. The hepatitis D virus (HDV) uses HBsAg as its surface protein, however, it is controversial to what extend HDV may be detected independently of HBsAg in blood and liver after LTX. The aims of this study were to investigate kinetics of HDV RNA and HBsAg early after LTX, to apply the data to a mathematical model and to study long-term persistence of HDV after LTX. We retrospectively analyzed 26 patients with chronic hepatitis delta who underwent LTX between 1994 and 2009. Blood samples were obtained every 1-3 days during the first 14 days after LTX. Data were applied to a mathematical model to study viral kinetics. Available liver biopsy samples were stained for HBV and HDV viral antigens and tested for HBV DNA/cccDNA. HBsAg and HDV RNA became negative after a median of 5 days (range 1-13) and 4 days (range 1-10), respectively. Early HDV RNA and HBsAg decline paralleled almost exactly in all patients; however the mathematical model showed a high variability of virion death. HDAg stained positive in transplanted livers in six patients in the absence of liver HBV DNA/cccDNA, serum-HBsAg, and HDV RNA for up to 19 months after LTX. HDV RNA and HBsAg decline follow almost identical kinetic patterns within the first days after LTX. Nevertheless, intrahepatic latency of HDAg has to be considered when exploring novel concepts to withdraw HBIG.

Diagnosis and monitoring of chronic viral hepatitis serologic and molecular markers

Chronic Hepatitis B (HBV) and Hepatitis C (HCV) virus infections are global health problems which may cause cirrhosis and even hepatocellular carcinoma. Hepatitis D virus (HDV) though a satellite virus of HBV, can also cause chronic infection. Serologic and molecular tools are needed for the diagnosis, monitoring and therapeutic management of chronic viral hepatitis associated with HBV, HDV and HCV. In HBV infection several serological markers are available for diagnosis and staging; while molecular assays are important for pretreatment evaluation, assessing drug response and identification of mutants. The endpoint of chronic HCV and HDV treatment is the sustained virological response, defined by an undetectable HCV/HDV RNA in serum with a sensitive assay 6 months after completion of treatment. HCV genotype and quantitative HCV RNA testing plays an important role in determining treatment duration, doses and also assess the likelihood of treatment response. Thus, virological assays are important in the diagnosis and management of individuals infected with chronic viral hepatitis.

Epidemiology, pathogenesis and management of hepatitis D: update and challenges ahead

Hepatitis D is caused by infection with the hepatitis D virus (HDV) and is considered to be the most severe form of viral hepatitis in humans. Hepatitis D occurs only in individuals positive for the HBV surface antigen (HBsAg) as HDV is a defective RNA viroid that requires HBsAg for transmission. At least eight different HDV genotypes have been described and each has a characteristic geographic distribution and a distinct clinical course. HDV and HBV coinfection can be associated with complex and dynamic viral dominance patterns. Chronic HDV infection leads to more severe liver disease than HBV monoinfection and is associated with accelerated fibrosis progression, earlier hepatic decompensation and an increased risk for the development of hepatocellular carcinoma. So far, only IFN-alpha treatment has proven antiviral activity against HDV in humans and has been linked to improved long-term outcomes. Studies conducted in the past 2 years on the use of PEG-IFN-alpha show that a sustained virologic response to therapy, measured in terms of undetectable serum HDV RNA levels, can be achieved in about one quarter of patients with hepatitis D. Novel alternative treatment options including prenylation inhibitors are awaiting clinical development for use in hepatitis D.

Positive Selection of Hepatitis Delta Antigen in Chronic Hepatitis D Patients

Liver disease may become ameliorated in some patients with chronic hepatitis D virus (HDV) infection. We present here a study based on longitudinal sampling to investigate the viral dynamics in chronic HDV infection. We examined the HDV variants from different time points, especially those before and after the elevation of serum aminotransferase levels. The datasets from each patient were tested for positive selection by using maximum-likelihood methods with heterogeneous selective pressures along the nucleotide sequence. An average of 4.9%, ranging from 3.1 to 6.8%, of the entire delta antigen sites was regulated by a diversifying selection. Most of the positively selected sites were associated with immunogenic domains. Likelihood ratio tests revealed a significant fitness of positive selection over neutrality of the hepatitis delta antigen gene in all patients. We further adapted a neural network method to predict potential cytotoxic T ligand epitopes. Among the HLA-A*0201 cytotoxic T ligand epitopes, three consistent epitopes across all three genotypes were identified: amino acids (aa) 43 to 51, 50 to 58, and 114 to 122. Three patients (60%) had sites evolving under positive selection in the epitope from aa 43 to 51, and four patients (80%) had sites evolving under positive selection in the epitope from aa 114 to 122. The discovery of immunogenic epitopes, especially cytotoxic-T-lymphocyte ligands, associated with chronic HDV infection may be crucial for further development of novel treatments or designs in vaccine for HDV superinfection.

Genotypes and Viremia of Hepatitis B and D Viruses Are Associated With Outcomes of Chronic Hepatitis D Patients

Genotypes and viremia of hepatitis D virus (HDV) and hepatitis B virus (HBV) may be associated with outcomes. This study evaluated the impact of viral genotypes and viremia on outcomes of dual HBV and HDV infection. Viremia and viral genotypes were analyzed in 194 consecutive chronic hepatitis B patients with HDV superinfection and correlated with outcomes. The numbers of HBV genotype A, B, C, and nonclassified were 4, 57, 23, and 110, respectively. There were 51 genotype I HDV, 74 genotype II HDV, 8 genotype IV HDV, and 61 nonclassified HDV genotype. In a median follow-up of 135 months, 24 progressed to cirrhosis and 41 developed hepatocellular carcinoma. Patients infected with genotype I HDV had a lower remission rate (15.2% vs 40.2%; P = .007) and more adverse outcomes (cirrhosis, hepatocellular carcinoma, or mortality) (52.2% vs 25.0%; P= .005) than those with genotype II HDV. Patients infected with genotype C HBV had a lower remission rate (0 vs 32.1%; P = .005) and more adverse outcomes (70.0% vs 33.9%; P = .005) than those with genotype B HBV. The presence of HBV or HDV viremia was associated with lower remission rates compared with those negative for both (26.4% and 24.3% vs 69.2%; P < .001). In multivariate analysis, age, genotype C HBV, and genotype I HDV were independent factors associated with adverse outcomes. In chronic HBV and HDV dual infections, older age, genotype I HDV, and genotype C HBV correlated with adverse outcomes.

“Defective” mutations of hepatitis D viruses in chronic hepatitis D patients

To verify whether "defective" mutations existed in hepatitis D virus (HDV). Hepatitis delta antigen (HDAg)-coding sequences were amplified using Pfu DNA polymerases with proof-reading activities from sera of five patients with chronic hepatitis D. Multiple colonies were sequenced for each patient. Pfu analyzed a total of 270 HDV clones. Three representative defective HDV clones were constructed in expression plasmids and transfected into a human hepatoma cell line. Cellular proteins were extracted and analyzed by Western blot. Four of five cases (80%) showed defective HDV genomes in their sera. The percentage of defective genomes was 3.7% (10/270). The majority (90%) of the defective mutations were insertions or deletions that resulted in frameshift and abnormal stop translation of the HDAg. The predicted mutated HDAg ranged from 45 amino acids to >214 amino acids in length. Various domains of HDAg associated with viral replication or packaging were affected in different HDV isolates. Western blot analysis showed defected HDAg in predicted positions. "Defective" viruses do exist in chronic HDV infected patients, but represented as minor strains. The clinical significance of the "defected" HDV needs further study to evaluate.

Anticardiolipin antibodies in chronic hepatitis B and chronic hepatitis D infection, and hepatitis B-related hepatocellular carcinoma. Relationship with portal vein thrombosis.

To assess the presence of anticardiolipin antibodies (ACAs) in patients with chronic hepatitis B virus (HBV) infection, chronic hepatitis D virus (HDV) infection and HBV-related hepatocellular carcinoma (HCC) and to associate this with the incidence of portal vein thrombosis (PVT) in HCC patients. Sixty-five cirrhotic patients with HBV-related HCC, 28 naive patients with chronic HBV infection and 14 naive patients with chronic HDV infection were enrolled prospectively in the study. Thirty-two healthy blood donors were used as controls. The ACAs (immunoglobulin G and immunoglobulin M) were measured using an enzyme-linked immunosorbent assay system. Statistical analysis used non-parametric methodology (chi-squared test, Student t-test and Fisher exact test, P value<0.05). Eleven of the 65 patients with HCC (16.9%) showed a positive ACA titre and 22 of the patients (34%) had PVT. Of these patients, eight (36%) had a positive ACA titre. In contrast, from the 43 patients without PVT, only three (11%) showed a positive titre. From the 28 HBV patients, six (21.5%) had a positive ACA titre, and six out of 14 (42.8%) HDV patients also showed a positive ACA titre. Three of the six ACA positive HBV patients presented an extrahepatic manifestation of the disease. One out of 32 control patients (3%) had positive ACAs. Both chronic HBV and chronic HDV infections are potent stimulants for the production of ACAs. The presence of ACAs in a great proportion of HBV-cirrhosis-related HCC patients with PVT suggests their possible participation in thrombotic mechanisms and in the hypercoagulable state that occurs in advanced liver disease and HCC.

Hepatitis D

The hepatitis D virus (HDV), also called delta virus, is a small circular RNA virus. The HDV is dependent on the hepatitis B virus (HBV) and can cause infection in normal individuals with hepatitis B or yet, superinfect chronic HBV carriers. Three genotypes have already been cloned and sequenced. Infection with HDV has a worldwide distribution and a high HDV endemicity has been documented in the western Amazon region, in Brazil. It has been estimated that 18 million people are infected with this virus amongst the 350 million carriers of the HBV around the world. The HDV transmission and risk factors for infection are similar to those for HBV infection. The diagnosis is based on the immunohistological identification of HDAg in the liver and detection of IgM and IgG anti-HD in serum using RIA or EIA. The clinical course of hepatitis D is variable. Fulminant disease occurs more commonly in hepatitis B and D than in other forms of acute viral hepatitis. Chronic HDV infection is usually associated with severe histological changes in the liver and with a rapidly progressive course, that can lead to cirrhosis, liver failure and death. Treatment of chronic hepatitis D is currently unsatisfactory and interferon alpha is the only agent found to have some effect on the course of chronic hepatitis. Orthotopic liver transplantation is indicated for terminal cases of cirrhosis. Prophylaxis for HDV infection is possible by vaccination against the hepatitis B virus.

Recent updates in hepatitis vaccination and the prevention of hepatocellular carcinoma.

Recent updates in hepatitis vaccination and the prevention of hepatocellular carcinoma.

Introduction of a new hepatitis agent in retrospect: genetic studies of Swedish hepatitis D virus strains.

The supposedly first outbreak of hepatitis D virus (HDV) infection in Sweden occurred among intravenous drug addicts in the Malmö area in the mid-1970s. Stored sera from this outbreak were used for viral RNA extraction and analysis. By sequence comparisons, the HDV genomes from those Swedish patients fell into two separate clusters, within which the RNA sequences were closely related. These two HDV groups genetically resembled the French and US-1 isolates of genotype I, respectively, indicating that there had been at least two separate sources of HDV infection. The genetic alterations of the HDV RNA were investigated by sequence analysis of nine annually drawn serum samples from one patient and paired samples collected between 2 and more than 10 years apart from six patients with chronic HDV infection. Only mutational changes were observed, and no insertion or deletion appeared throughout the periods observed. It was found that the Swedish HDV isolates mutationally evolved at an average rate of 1.1 x 10(-3) substitutions per nucleotide per year over a long time course of chronic HDV infection, which is of the same magnitude as that of other RNA viruses.

Splenomegaly in asymptomatic chronic carriers of hepatitis B and D viruses

To investigate whether splenomegaly, a common and striking feature of hepatitis D virus (HDV)-related cirrhosis, is manifested in both the late cirrhotic phase and the early and asymptomatic stages of chronic HDV infection. A blind ultrasonographic study of HDV-positive and -negative hepatitis B surface antigen (HBsAg) carriers in the Community of Archangelos of Rhodes Island, Greece, where HDV infection is endemic. The ultrasonographic findings were compared with clinical, biochemical and demographic data by uni- and multivariate analysis. The study population comprised 47 HDV-positive and 78 HDV-negative asymptomatic HBsAg carriers. A maximal longitudinal diameter of the spleen of >12cm and >15cm was detected in 13 of 47 (27.7%) and three of 47 (6.4%) of the HDV-positive and in 13 of 78 (16.7%) and three of 78 (3.8%) of the HDV-negative group, respectively (P>0.1). Splenomegaly (>12cm) was associated with significant dilation of the portal vein and enlargement of the left hepatic lobe. Multivariate analysis demonstrated that in both the HDV-positive and -negative HBsAg carriers, factors associated with chronic hepatic injury and/or biochemical markers of liver necro-inflammation correlated significantly with splenomegaly and could explain most of the variability in splenic size, particularly in the HDV-positive group. Although splenomegaly is more frequent and pronounced in chronic liver disease due to HDV than in HBV disease alone, it does not appear to be a feature specific to chronic HDV infection. The main determinants of splenic enlargement in the present field study of HBsAg carriers were found to be liver necro-inflammation and ultrasonographic indices of portal hypertension, regardless of the presence or absence of HDV infection.

Differential effect of chronic hepatitis D virus infection on intrahepatic expression of hepatitis B viral antigen.

To determine how chronic hepatitis D virus (HDV) infection affects intrahepatic hepatitis B virus (HBV) antigen expression. Ninety eight liver biopsy specimens from 68 patients seropositive for total antibody to HDV were studied by immunohistochemistry, and the amount of HBV antigens was also quantified by radioimmunoassay in 12 patients and compared with 30 patients with chronic HBV infection. Forty nine of the 68 patients were positive for intrahepatic HDV antigen and only five were positive for HBV core antigen (HBcAg). HBV surface antigen (HBsAg) was present in 55 (80.9%) patients and was always cytoplasmic in distribution. Hepatic pre-S1 and pre-S2 expressions paralleled that of HBsAg, and were detected in 53 (77.9%) and 54 (79.4%) patients, respectively. There was no relation between the intrahepatic expression of HDV antigen and HBsAg/pre-S1/pre-S2. Follow up biopsy specimens in 25 patients showed either static or deteriorating histology while intrahepatic HDV antigen remained the same or fell. The patients with intrahepatic expression of HBcAg had either absent or noticeably decreased expression of HBcAg in their follow up biopsy specimens (median two years). In contrast, HBsAg/pre-S1/pre-S2 were the same or increased (p less than 0.001). Quantification of intrahepatic HBsAg in patients with chronic HDV infection (0.61 pg/hepatocyte, range: 0.05-1.08, n = 12) showed no difference with patients with chronic HBV infection alone (0.64 pg/hepatocyte, range: 0.02-1.02, n = 30, p = NS). These data indicate that chronic HDV infection suppresses intrahepatic expression of HBcAg but not HbsAg and pre-S antigens, suggesting a differential effect of chronic HDV infection on HBV gene expression.

Significance of IgM anti‐hepatitis D virus (HDV) in chronic HDV infection

Intrahepatic hepatitis D virus (HDV) antigen (HDAg) and serum HDV RNA are excellent markers of active HDV replication but the relation of IgM anti-HDV to HDV replication and histological activity is less certain. To further elucidate the significance of serum IgM anti-HDV, 90 paired sera and liver biopsies from 64 patients seropositive for total antibody to HDV were analysed for IgM anti-HDV, intrahepatic HDAg expression, and histological inflammatory activity. IgM anti-HDV was strongly associated with intrahepatic HDAg expression with a sensitivity of 94.1% but the assay lacked specificity since 14 out of 22 cases negative for intrahepatic HDAg were also positive for IgM anti-HDV. In 20 patients in whom follow-up biopsies and paired sera were available, two patients lost intrahepatic HDAg but paired serum remained IgM anti-HDV positive. Although the presence of serum IgM anti-HDV correlated significantly with a higher histological inflammatory activity (P = 0.001), there was a considerable overlap with the group seronegative for IgM anti-HDV, again indicating a poor specificity. This lack of specificity of IgM anti-HDV for both HDV replication and histological activity indicates that this assay provides no additional information over and above assay for total antibody to HDV.

The serology of delta hepatitis and the detection of IgM anti-HD by EIA using serum derived delta antigen

A sensitive and specific capture assay for IgM antibody to hepatitis D virus (HDV) was developed employing serum-derived delta antigen (HDAg). In a retrospective and prospective study of an outbreak of hepatitis B (HB), 135 hepatitis B surface antigen (HBsAg) positive drug-abusers with acute hepatitis and 18 HBsAg carriers, attending various hospitals and clinics in Dublin, were found to be infected with HDV. Serological follow-up was available from 24 of those with acute hepatitis allowing a comparison of the duration and level of IgM anti-HD with the more commonly used markers, HDAg and anti-delta (anti-HD), and an assessment of the usefulness of each. HDV and HB serology was grossly altered by human immunodeficiency virus (HIV) in two patients, with severe clinical manifestation in one. All 135 patients with HDV co-infection had delta antigenaemia. In co-infections with optimum sampling times, the mean duration of delta antigenaemia was 21 days. IgM anti-HD was always found between HDAg and sero-conversion to anti-delta and was the only ‘window’ marker present in five cases. The mean duration of IgM anti-HD was four weeks (optimum at 2.8 weeks) and was of moderate or low titre and occurred simultaneously with HDAg in 78%. In HDV-infected HBsAg carriers, high-litre IgM anti-HD ( > 1 10000 ) persisted for the duration of the study and is a useful indicator of chronic HDV infection. IgM anti-HD was not found in 202 random blood donors nor in 205 patients with non-B hepatitis or other disorders. Total (IgG) anti-HD persisted in all patients (except the two reactivations) at titres of less than 1 1000 in co-infections and greater than 1 5000 in carriers, for the duration of follow-up. We conclude that HDAg is singly the best marker of HDV co-infection and. where only late specimens are available. IgM anti-HD is also useful. IgM anti-HD will also distinguish between chronic HDV infection and previous exposure.

Chronic hepatitis D virus (HDV) infection in hepatitis B virus carrier chimpanzees experimentally superinfected with HDV.

Chimpanzees that were chronic hepatitis B virus carriers and that were superinfected with hepatitis D virus (HDV) apparently developed acute, self-limited type D hepatitis. Reevaluation with a sensitive hybridization-based assay using RNA probes specific for the HDV genome, however, demonstrated that greater than 50% of these animals still had detectable signs of ongoing HDV replication an average of 2.4 y (range, 1-6.4 y) after inoculation. The only positive marker for the presence of HDV was serum HDV RNA; HDV antigen was undetectable in both serum and the liver by an immunoblot assay and immunofluorescence, respectively. Because the detected amount of viral genome was very low, the previous failure to identify the chronic HDV carrier state in the chimpanzee can be attributed to the lower sensitivity of previously described assays.