Clinical and virological heterogeneity of hepatitis delta in different regions world-wide: The Hepatitis Delta International Network (HDIN)

New epidemiology of hepatitis delta

Hepatitis D virus (HDV) is a defective pathogen that needs hepatitis B virus (HBV) for infection. Co-infection of HBsAg-positive individuals with HDV is commonly associated with a more rapid progression to cirrhosis, a higher incidence of hepatocellular carcinoma (HCC) and increased mortality. Initial studies have shown that about 5% of chronic HBV carriers worldwide (15-20 millions) were also infected with HDV. However, recent studies suggest that the prevalence of HDV is at least two- to three-fold higher than previous estimations. Improved diagnostic techniques have shown that HDV infection remains endemic in certain areas of the world. Injection drug users, individuals with high-risk sexual behaviour and patients co-infected with human immunodeficiency virus (HIV) represent the major reservoir of the disease in the Western world. Although the burden of HDV infection significantly decreased in Europe in the nineties, there has been no further decrease in the last decade, probably because of migration from HDV endemic countries. Until new and more effective therapies are available, public health measures should be reinforced by increasing prophylactic HBV vaccination programs, preventing transmission of the virus among parenteral drug users and implementing universal HDV screening of all HBV-infected individuals.

Treatment of chronic hepatitis due to hepatitis B and hepatitis delta virus coinfection

An estimated 20-40 million individuals worldwide are infected with hepatitis delta virus (HDV), mostly with rapidly evolving liver disease. Therapy of chronic HDV infection remains an unmet need. To date, only interferon (IFN)-based therapy is recommended for HDV infection and response rates are unsatisfactory; in addition, many patients are intolerant to or ineligible for IFN treatment. In recent years, innovative approaches have been in development, including the following: targeting virus entry into hepatocytes; inhibition of the host enzyme farnesyltransferase by prenylation inhibitors, leading to inhibition of complete virion formation and release; blockade of hepatitis B surface antigen (HBsAg) secretion, inhibiting virus release; and IFN-lambda, which causes fewer adverse effects than IFN-alfa. Clinical trials are ongoing with encouraging preliminary results.

Chronic hepatitis delta: A state-of-the-art review and new therapies

Chronic delta hepatitis is the most severe form of viral hepatitis affecting nearly 65 million people worldwide. Individuals with this devastating illness are at higher risk for developing cirrhosis and hepatocellular carcinoma. Delta virus is a defective RNA virus that requires hepatitis B surface antigen for propagation in humans. Infection can occur in the form of a co-infection with hepatitis B, which can be self-limiting, vs superinfection in a patient with established hepatitis B infection, which often leads to chronicity in majority of cases. Current noninvasive tools to assess for advanced liver disease have limited utility in delta hepatitis. Guidelines recommend treatment with pegylated interferon, but this is limited to patients with compensated disease and is efficacious in about 30% of those treated. Due to limited treatment options, novel agents are being investigated and include entry, assembly and export inhibitors of viral particles in addition to stimulators of the host immune response. Future clinical trials should take into consideration the interaction of hepatitis B and hepatitis D as suppression of one virus can lead to the activation of the other. Also, surrogate markers of treatment efficacy have been proposed.

Biobanking for Viral Hepatitis Research

Introduction: Viral hepatitis is a worldwide, important health issue. The optimal management of viral hepatitis infections faces numerous challenges. In this paper, we describe how biobanking of biological samples derived from viral hepatitis patients collected both in-hospital and during community outreach screenings provides a unique collection of samples. Materials and Methods: All samples and materials were provided with a study code within the SLIMS system Study protocols and an informed consent form were approved by the Antwerp University Hospital/University of Antwerp Ethical Committee. Systematic biobanking was initiated in October 2014. Collected sample types include: (1) serum and plasma of all newly diagnosed HBV, HCV, HDV, and HEV positive patients; (2) left-over serum and plasma samples from all PCR analyses for HBV and HCV performed in the context of routine clinical care; (3) left-over liver tissue not needed for routine histological diagnosis after liver biopsy; and (4) additional virus-specific, appropriate sample types using a scientific rationale-based approach. A community outreach screening program was performed in three major Belgian cities. Serum, EDTA, Tempus Blood RNA and BD Vacutainer CPT were collected. CPT tubes were centrifuged on-site and mononuclear cells collected within 24 h. Results: Concerning community screening: 298 individuals supplied all 4 sample types. Samples were stored at -150°C and were logged in the biobank SLIMS database. Samples were used for HBV-related immunological and biomarker studies. DNA isolated from plasma samples derived from chronic HBV patients was used to investigate Single Nucleotide Polymorphism rs 1790008. Serum samples collected from chronic hepatitis C patients were used to assess the efficacy of HCV treatment. Peripheral Blood Mononuclear Cells (PBMC) isolated from chronic HBV patients and healthy controls were used for different immunological study purposes. Virus isolated from biobanked stool of a chronic hepatitis E patient was used to establish a mouse model for Hepatitis E infections, allowing further HEV virology studies. Conclusion: The establishment of a biobank with samples collected both in-hospital and during community-outreach screening resulted in a unique, continuously expanding collection of biological samples which provides an excellent platform for prompt answers to clinically and translational relevant research questions.

Recurrence of Hepatitis D Virus in Liver Transplant Recipients With Hepatitis B and D Virus-Related Chronic Liver Disease

PURPOSE

Data on recurrence of hepatitis D virus (HDV) and its long-term impact on liver transplant (LT) are limited. In this study, we investigated the incidence of hepatitis B virus (HBV) and the long-term effect of postoperative HDV recurrence HDV coinfection in our liver transplant patients.

PATIENTS AND METHODS

Between 2004 and 2018, all patients with LT because of HBV (n = 361; 37.3%) were reviewed, and those with HBV and HDV coinfection (n = 104; 30% of all HBV patients) were enrolled in our study. All patients received post-transplant combination therapy with nucleos(t)ide analogue and antihepatitis B immunoglobulins. Breakthrough infection was defined as reemergence of HBV DNA or hepatitis B surface antigen during postoperative treatment. In case of recurrence, another oral nucleos(t)ide analogue was added and antihepatitis B immunoglobulins were stopped.

RESULTS

During the study period, the frequency of HDV (+) was decreased (41% to 14%). Median follow-up time was 82 months (range, 1-274 months). Post LT survival and HBV recurrence were 97% (n = 15) and 13.4%, respectively. Only 15 patients (14%) developed breakthrough infection. There was no predictive factor for recurrent HDV infection, including demographics data and concomitant hepatocellular carcinoma (P = .73). Mortality was similar between patients with and without recurrence (2.2% vs 7.1%, P = .35) CONCLUSIONS: Patients who received transplants for hepatitis B and D virus cirrhosis had favorable prognosis and good long-term results despite recurrent infection. Close follow-up of patients and effective postoperative viral suppression with appropriate medications seems to be favorable for both prevention and management of recurrence and provides comparable outcome with patients without recurrence.

Hepatitis D infection: from initial discovery to current investigational therapies

Hepatitis D is the most severe form of viral hepatitis associated with a more rapid progression to cirrhosis and an increased risk of hepatocellular carcinoma and mortality compared with hepatitis B mono-infection. Although once thought of as a disappearing disease, hepatitis D is now becoming recognized as a serious worldwide issue due to improvement in diagnostic testing and immigration from endemic countries. Despite these concerns, there is currently only one accepted medical therapy (pegylated-interferon-α) for the treatment of hepatitis D with less than desirable efficacy and significant side effects. Due to these reasons, many patients never undergo treatment. However, increasing knowledge about the virus and its life cycle has led to the clinical development of multiple promising new therapies that hope to alter the natural history of this disease and improve patient outcome. In this article, we will review the literature from discovery to the current investigational therapies.

The oncogenic role of hepatitis delta virus in hepatocellular carcinoma

Hepatitis delta virus (HDV) is a small defective virus that needs hepatitis B virus (HBV) to replicate and propagate. HDV infection affects 20-40 million people worldwide and pegylated interferon (PegIFN) is the only recommended therapy. There is limited data on the contribution of HDV infection to HBV-related liver disease or liver cancer. Evidence from retrospective and cohort studies suggests that HBV/HDV coinfection accelerates progression to cirrhosis and is associated with an increased risk of hepatocellular carcinoma (HCC) development compared to HBV monoinfection. Although the life cycle of HDV is relatively well known, there is only ancillary information on the molecular mechanisms that can drive specific HDV-related oncogenesis. No thorough reports on the specific landscape of mutations or molecular classes of HDV-related HCC have been published. This information could be critical to better understand the uniqueness, if any, of HDV-related HCC and help identify novel targetable mutations. Herein, we review the evidence supporting an oncogenic role of HDV, the main reported mechanisms of HDV involvement and their impact on HCC development.

A review on hepatitis D: From virology to new therapies

Hepatitis delta virus (HDV) is a defective virus that requires the hepatitis B virus (HBV) to complete its life cycle in human hepatocytes. HDV virions contain an envelope incorporating HBV surface antigen protein and a ribonucleoprotein containing the viral circular single-stranded RNA genome associated with both forms of hepatitis delta antigen, the only viral encoded protein. Replication is mediated by the host cell DNA-dependent RNA polymerases. HDV infects up to72 million people worldwide and is associated with an increased risk of severe and rapidly progressive liver disease. Pegylated interferon-alpha is still the only available treatment for chronic hepatitis D, with poor tolerance and dismal success rate. Although the development of antivirals inhibiting the viral replication is challenging, as HDV does not possess its own polymerase, several antiviral molecules targeting other steps of the viral life cycle are currently under clinical development: Myrcludex B, which blocks HDV entry into hepatocytes, lonafarnib, a prenylation inhibitor that prevents virion assembly, and finally REP 2139, which is thought to inhibit HBsAg release from hepatocytes and interact with hepatitis delta antigen. This review updates the epidemiology, virology and management of HDV infection.

Evaluation of dried blood spots for hepatitis B and D serology and nucleic acid testing

Areas with the highest burden of hepatitis B virus (HBV) infection are often low-middle-income countries with limited access to diagnosis due to isolation, affordability, and/or feasibility. Dried blood spots (DBSs) provide an alternative for remote areas where collection and transportation of serum is impractical. In this study, the application of DBS for serological and molecular detection of HBV and hepatitis D virus (HDV) was evaluated. Hepatitis B surface antigen was detected in 87 of 91 (95.6%) DBS. Seventeen of 21 (81%) had detectable HBeAg and 52 of 71 (73.2%) were anti-HBe positive. Anti-HD was detectable in 11 of 12 (91.6%) spiked control DBS after an initial failure to detect in patient DBS. HBV DNA was detected from 50 of 70 (71.4%) DBS with serum loads greater than 200 IU/mL in an in-house assay and 18 of 24 (75%) DBS with loads exceeding 389 IU/mL in a commercial assay. Using linear regression, HBV DNA loads from DBS were able to predict serum loads in 46 of 50 (92%) samples to within 1 log of actual serum load. HDV RNA was detected in 42 of 47 (89%) DBS with serum levels greater than 7200 IU/mL. DBSs are recommended for diagnosis of HBV, monitoring, and detection of high loads in pregnant women where peripheral blood testing remains unfeasible. Detection of HDV RNA from DBS may prove useful in endemic areas.

Clinical outcomes in patients with hepatitis D, cirrhosis and persistent hepatitis B virus replication, and receiving long-term tenofovir or entecavir

BACKGROUND

Suppression of hepatitis B virus (HBV) replication with nucelos(t)ide analogues should be considered for patients with chronic hepatitis D virus (HDV) infection and ongoing HBV replication.

AIM

To verify the clinical outcome after long-term entecavir or tenofovir treatment in patients with advanced fibrosis/cirrhosis, ineligible to peg-interferon therapy.

METHODS

Patients were prospectively followed-up at 3-6 month intervals; measured outcomes were decompensation, hepatocellular carcinoma (HCC), liver transplant and liver related death. HBV monoinfected patients receiving the same treatment served as reference after 1:1 matching by age, gender, platelet count, albumin level, bilirubin and INR.

RESULTS

56 HDV patients (48 with cirrhosis; median follow-up 50 months) were enrolled; all achieved HBV DNA suppression. Death or liver transplant occurred in 19 patients, with a rate (n/1000 patient-months) of 2.92 in HDV patients vs 0.38 in HBV monoinfected patients (P < 0.001); similarly, decompensation occurred at a rate of 1.53 vs 0.13 (P = 0.015), respectively, and the rate of HCC was almost thrice in HDV cohort (3.12 vs 1.12; P = 0.02) Platelet count, Child-Pugh score and marginally HDV infection were associated with HCC development.

CONCLUSION

Patients with HDV infection and advanced liver disease maintain an increased risk of severe clinical events as compared with HBV monoinfected patients, during prolonged HBV DNA suppression with potent NA.

Profile of hepatocellular carcinoma in the Republic of Moldova: first-hand information on the presentation, distribution and etiologies

INTRODUCTION

Moldova is the European country with the highest incidence of hepatocellular carcinoma (HCC) in both sexes. There is, however, no data comprehensively describing the presentation and the risk factors of HCC in the country. We decided to analyze cases of HCC recently received in a tertiary healthcare Institution from Chisinau, the Moldovian capital.

METHODS

A series of 148 primary liver tumors including 139 cases of HCC were retrospectively analyzed for demographic features, serological and biochemical data, and clinical presentation.

RESULTS

The mean age of patients was 59 ± 10 years (range: 19-66) with a M:F sex ratio of 1.9. Tumors appeared on full-blown liver cirrhosis in 83% of cases and were composed of multiple nodules at diagnosis in 36% of patients. Serum Alpha-fetoprotein was exceeding 10ng/mL in 76% of cases. Liver tumor and hepatitis were co-discovered in 34% of cases. More than 81% of hepatocellular carcinomas were associated with at least one hepatitis virus. Carriers of anti-hepatitis C virus were predominating (55% of cases) over patients seropositive for hepatitis B virus surface antigen (36%). Half of the latter were also infected with hepatitis Delta virus. In total, dual or triple infections were present in 24% and 7% of cases.

CONCLUSIONS

The burden of infections with hepatitis viruses is particularly important in Moldova and corresponds to a situation commonly observed in countries of the Southern hemisphere. A pro-active policy of screening for persistent liver infection targeting population at risk of HCC (> 50 years) and coupled with the distribution of antivirals in positive cases should be rapidly implemented in Moldova to reduce incidence or primary liver cancer.

Recombinant identification, molecular classification and proposed reference genomes for hepatitis delta virus

Hepatitis delta virus (HDV), as a defective sub-virus that co-infects with hepatitis B virus, imposes an emerging global health burden. However, genetic characteristics and molecular classification of HDV remain under investigated. In this study, we have systematically retrieved and analysed a large set of HDV full-length genome sequences and identified novel recombinants. Based on phylogenetic and genetic analyses, we have established an updated classification system for HDV when recombinants were excluded. Furthermore, we have mapped the global distribution of different genotypes and subtypes. Finally, we have compiled a complete set of reference genomes for each subtype and proposed criteria for future identification of novel genotypes and subtypes. Of note, the global distribution map indicates that currently available HDV genetic data remain limited, and thus our proposed classification will likely evolve as future epidemiological data will accumulate. These results will facilitate the future research on the diagnosis, screening, epidemiology, evolution, prevention and clinical management of HDV infection.

The Epidemiology of Hepatitis D Virus in North Africa: A Systematic Review and Meta-Analysis

BACKGROUND

Hepatitis D virus (HDV) infection has been considered a serious neglected pandemic, particularly in developing countries. The virus causes a more severe disease than mono infection with hepatitis B virus (HBV). The epidemiology of HDV is not well documented in North Africa, which is known to be endemic for HBV. In this study, we explored the prevalence of HDV infection and also attempted to identify factors associated with hepatitis D positive status among chronic hepatitis B patients in North Africa.

METHODS

The electronic databases PubMed, Embase, Scopus, Science Direct, Web of Science, and Google Scholar were comprehensively searched for all papers published between January 1, 1998, and December 31, 2017, using appropriate strategies containing all related keywords, including North Africa, names of countries in the region, and all permutations of hepatitis D virus. The estimated prevalence of HDV in North Africa was calculated as an average of the pooled infection prevalence in each country weighted by the ratio of the country's hepatitis D virus population to the study's sample size in the survey data analysis.

FINDINGS

A total of 312 studies were identified and 32 were included in this study, with a total sample of 4907 individuals screened for HDV. There was considerable variability in the prevalence estimates of HDV within the countries of the region. The overall prevalence of HDV in the general population of North Africa was 5·01% (95% CI: 1·25-8·27) and in liver disease patients it was 20.7% (95% CI:9.87-44.53). Genotype-1 was the most prominent genotype reported in five published studies. Ten studies reported on HDV RNA in participants who were seropositive for HDV, and four studies highlighted the impact of demographic factors (sex and age). No study showed the impact of risk factors on the prevalence of HDV in North Africa.

INTERPRETATION

This review provides a comprehensive assessment of the burden of HDV in Northern Africa. There were significant differences in seroprevalence, study population, and diagnostic testing between the countries in the region. The results presented here will alert health professionals to implement clear policies based on evidence to diminish the burden of HDV infection. Such measures may include but are not restricted to improving the laboratory diagnostic tests and initiating patient data registries and blood screening. Further epidemiological and research studies are needed to explore the risk factors, coinfections, and approaches to increase testing for HDV, particularly in high-risk subpopulations, such as intravenous drug users and immigrants, and to define the consequences of HDV infection in North Africa.

Screening for hepatitis D and PEG-Interferon over Tenofovir enhance general hepatitis control efforts in Brazil

Background

Hepatitis D virus (HDV), which requires the presence of hepatitis B virus (HBV), is a deadly yet neglected disease that rapidly leads to liver cancer and disease-induced mortality. This co-dependence creates complex transmission dynamics that make it difficult to predict the efficacy of interventions aimed at HBV and/or HDV control in endemic regions, such as certain municipalities of Brazil, where up to 65% of HBV-infected persons are co-infected.

Methodology

We created a mathematical model that captures the joint transmission dynamics of HBV and HDV, incorporating mother-to-child, sexual and household transmission. With an aim to minimize the number of total infections and disease-induced mortality in 2027, we then determined optimal strategies for Brazil and its sub-regions under a constrained budget, which was dynamically allocated among HBV and HDV screening, HBV and HDV treatment, HBV newborn and adult vaccination, and awareness programs. Three treatment options were considered, namely: Tenofovir, PEGylated-Interferon, and nucleic acid polymers (NAP).

Results

The additional cost of HDV screening and the use of a more expensive PEGylated-Interferon are offset by not wasting resources on treating co-infected persons with Tenofovir. The introductory price of NAP treatment must be less than $16,000 per course to become competitive with Tenofovir and PEGylated-Interferon in Brazil.

Conclusion

Additional screening for HDV is beneficial, even in a low HBV and HDV endemic regions of Brazil. We recommend PEGylated-Interferon, wherever possible, for both HBV and HDV. If PEGylated-Interferon is not available in abundance, PEGylated-Interferon for co-infections and 4-year Tenofovir treatment for mono-infections is recommended.

Prevalence and incidence of hepatitis delta in patients with chronic hepatitis B in Spain

BACKGROUND

Hepatitis delta virus (HDV) is a defective agent that only replicates in the presence of the hepatitis B virus. Accordingly, HDV acquisition may occur as superinfection of HBsAg+ carriers or following acute dual HDV and hepatitis B virus exposure. Herein, we examined the global and incident rates of HDV infections in Spain.

PATIENTS AND METHODS

The presence of anti-HDV antibody and new HDV superinfections was examined in all HBsAg+ patients who attended one large tertiary outclinic in Spain since year 2000. Anti-HDV antibodies were tested repeatedly every 5 years in those previously negative.

RESULTS

During a median follow-up of 12 years, 478 individuals were diagnosed as HBsAg+. Overall, 64.4% were male, median age was 55 years, 88.1% were native Spaniards, 6.5% were coinfected with HIV, and 7.3% were reactive for hepatitis C virus (HCV) antibodies.A total of 19 (4%) patients had anti-HDV antibody at first diagnosis. There were no further HDV seroconversions. Most anti-HDV+ patients were male (n=12), former injection drug users (n=13), and native Spaniards (n=16). Coinfection with HIV was found in six, and 12 had HCV antibodies. Interestingly, three of seven women with delta hepatitis were foreigners (Asian or African), denied injection drug use, were younger than 40 years old, and negative for both HCV and HIV.

CONCLUSION

The prevalence of chronic hepatitis delta is currently very low (<5%) among chronic HBsAg+ carriers in Spain, with lower rates in recent years. Moreover, new incident HDV infections were not seen in 478 chronic hepatitis B carriers since year 2000, following drastic declines in injection drug use.

HDV Can Constrain HBV Genetic Evolution in HBsAg: Implications for the Identification of Innovative Pharmacological Targets

Chronic HBV + HDV infection is associated with greater risk of liver fibrosis, earlier hepatic decompensation, and liver cirrhosis hepatocellular carcinoma compared to HBV mono-infection. However, to-date no direct anti-HDV drugs are available in clinical practice. Here, we identified conserved and variable regions in HBsAg and HDAg domains in HBV + HDV infection, a critical finding for the design of innovative therapeutic agents. The extent of amino-acid variability was measured by Shannon-Entropy (Sn) in HBsAg genotype-d sequences from 31 HBV + HDV infected and 62 HBV mono-infected patients (comparable for demographics and virological-parameters), and in 47 HDAg genotype-1 sequences. Positions with Sn = 0 were defined as conserved. The percentage of conserved HBsAg-positions was significantly higher in HBV + HDV infection than HBV mono-infection (p = 0.001). Results were confirmed after stratification for HBeAg-status and patients’ age. A Sn = 0 at specific positions in the C-terminus HBsAg were correlated with higher HDV-RNA, suggesting that conservation of these positions can preserve HDV-fitness. Conversely, HDAg was characterized by a lower percentage of conserved-residues than HBsAg (p < 0.001), indicating higher functional plasticity. Furthermore, specific HDAg-mutations were significantly correlated with higher HDV-RNA, suggesting a role in conferring HDV replicative-advantage. Among HDAg-domains, only the virus-assembly signal exhibited a high genetic conservation (75% of conserved-residues). In conclusion, HDV can constrain HBsAg genetic evolution to preserve its fitness. The identification of conserved regions in HDAg poses the basis for designing innovative targets against HDV-infection.