Hepatitis delta: virological and clinical aspects

The effect of Hepatitis D co-infection on the immunologic and molecular profile of Hepatitis B in asymptomatic Chronic Hepatitis B patients in southwest Nigeria

Introduction: Hepatitis D infection causes severe form of viral hepatitis in humans and only affects those with hepatitis B either as a co-infection or superinfection. The aim of this study was to determine the prevalence of Hepatitis D and its effect on the immunologic and molecular profile of Hepatitis B among asymptomatic Chronic Hepatitis B patients in Abeokuta.Methodology: A cross-sectional study of 99 chronic HBV patient who met the inclusion criteria. All the patients were tested for HBsAg, anti HCV, HDV antigen, anti HDV, HBsAg quantification, and HBV DNA quantification. Associations were tested for and P value less than 0.05 was considered significant.Results: The participants included 53 (58%) male and 38 (42%) females with ages ranging from 18 to 69 (means 39 ± 11) years. Ten (11%) participants were positive for HDV-Ag while 1 (1.1%) was positive for anti-HDV. Five (5.5%) were positive for HIV 1 &2 while 1 (1.1%) was positive for anti HCV. HBV DNA quantification ranged from 15 to 17,000,000 IU/ml while HBsAg quantification ranged from 0.25 to45,520 IU/ml. There was no statistically significant relationship between HDV-Ag and age (p = .51), sex (p = .73), HBV DNA (p = .8) and HBsAg quantification (p = 1).Conclusion: The prevalence of HDV-Ag among asymptomatic treatment naïve chronic hepatitis B patients in Abeokuta was 11% and there was no significant difference in the levels of HBV DNA and HBsAg among those with or without hepatitis D.

Targeting the Host for New Therapeutic Perspectives in Hepatitis D

Hepatitis D virus (HDV) is a small satellite virus of hepatitis B virus (HBV) requiring HBV infection to complete its life cycle. It has been recently estimated that 13% of chronic HBV infected patients (60 million) are co-infected with HDV. Chronic hepatitis D is the most severe form of viral hepatitis with the highest risk to develop cirrhosis and liver cancer. Current treatment is based on pegylated-interferon-alpha which rarely controls HDV infection and is complicated by serious side effects. The development of novel antiviral strategies based on host targeting agents has shown promising results in phase I/II clinical trials. This review summarizes HDV molecular virology and physiopathology as well as new therapeutic approaches targeting HDV host factors.

Phylodynamic and Phylogeographic Analysis of Hepatitis Delta Virus Genotype 3 Isolated in South America

The hepatitis delta virus (HDV) is a globally distributed agent, and its genetic variability allows for it to be organized into eight genotypes with different geographic distributions. In South America, genotype 3 (HDV-3) is frequently isolated and responsible for the most severe form of infection. The objective of this study was to evaluate the evolutionary and epidemiological dynamics of HDV-3 over the years and to describe its distribution throughout this continent in an evolutionary perspective. While using Bayesian analysis, with strains being deposited in the Nucleotide database, the most recent common ancestor was dated back to 1964 and phylogenetic analysis indicated that the dispersion may have started in Brazil, spreading to Venezuela and then to Colombia, respectively. Exponential growth in the effective number of infections was observed between the 1950s and 1970s, years after the first report of the presence of HDV on the continent, during the Labrea Black Fever outbreak, which showed that the virus continued to spread, increasing the number of cases decades after the first reports. Subsequently, the analysis showed a decrease in the epidemiological levels of HDV, which was probably due to the implantation of the vaccine against its helper virus, hepatitis B virus, and serological screening methods implemented in the blood banks.

Prevalence of hepatitis delta infections among HBs-antigen-positive inhabitants of southeastern and northwestern parts of Poland

Hepatitis delta (HDV) virus still poses a serious health problem worldwide. Being a satellite particle, it may complete its life cycle only in the presence of HBs antigen produced by hepatitis B virus (HBV). According to epidemiological data, about 5% of HBs antigen carriers are infected with this virus, which equates to approximately 15-20 million individuals worldwide. Although the infection with both HBV and HDV viruses is considered to be the worst form of viral hepatitis, the only approved treatment, with pegylated interferon α, is not satisfactory. Thus effective and safe therapy is still lacking, which stands in contrast to the latest development in therapeutic areas of HBV and hepatitis C virus (HCV) infections. As the exact data on prevalence of this infection in some countries as well as natural history of this disease are still incomplete, further studies are warranted. Polish investigations on this field are very scarce and at most dating from the 1990s. This publication makes another attempt to broaden our knowledge of this temporarily forgotten but still ongoing and complex problem.

Comparison of anti-hepatitis D virus (HDV) ETI-AB-DELTAK-2 assay and the novel LIAISON® XL MUREX anti-HDV assay in the diagnosis of HDV infection

Hepatitis B/D virus infection leads to severe liver disease. HDV infection is not routinely investigated since the diagnosis is based on enzyme immunoassays (EIAs), which are not available in all laboratories. This study investigates the performance of new automated assay for anti HDV Ab detection: LIAISON® XL Murex anti-HDV. HBsAg-positive samples were evaluated for HDV serology using the ETI-AB-DELTAK-2 and the new LIAISON® XL Murex with a concordance of 97.5% and 2.42% discordant results. The discordant specimens reacted negatively with EIA and positively with the new test. Dilutions of HDV-purified antibodies and HDV-positive samples were tested with both assays, showing a lower detection limit for the new assay. In conclusion, LIAISON® XL Murex showed a good concordance with the reference method and allowed a more rapid HDV detection. This new diagnostic tool may be useful for a more efficient approach to the HDV diagnosis and evaluation of HDV epidemiology.

Evolutionary trends in the prevalence of anti-HDV antibodies among patients positive for HBsAg referred to a national laboratory in Cameroon from 2012 to 2017

Objective

The aim of this study was to update the data on the prevalence of anti-HDV antibodies in Cameroon.

Results

Antibodies against hepatitis Delta virus (Anti-HDV) were found in 16.48% (95% CI 11.46–18.77%) of 426 hepatitis B virus surface antigen positive patients in Cameroon. Remarkably, they were significantly higher among people over 40 years and those living in the East and South regions of Cameroon at 66.7%, 50%, and 40%, respectively. These results suggest that older age and living in areas in the dense forest may be risk factors for Hepatitis D infection.

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.

Access to 3-spiroindolizines containing an isoindole ring through intra-molecular arylation of spiro-N-acyliminium species: a new family of potent farnesyltransferase inhibitors

Based on N-acyliminium species, two efficient and rapid approaches to diversify spirocyclic systems connected by two different carbon centers to the isoindole ring have been developed. The imide reduction and the tandem oxidative cleavage of olefin/formyl-amide equilibration were at first selected as the key steps for these strategies. Ultimately the intramolecular α-amidoalkylation reaction was achieved through the arylation of α-acetoxy lactams or α-hydroxy lactams using, respectively, a Lewis acid or a Brønsted acid depending on the nature of N-acyliminium precursors. The latter led, in addition to the spiro-6-membered aza-heterocycles, to the formation of scarce spiro-5-membered analogues which show promising inhibitory activities on human farnesyltransferase in the nanomolar range demonstrating improved IC50 values of up to 1.5 nM.

Hepatitis Delta Prevalence in South America: A Systematic Review and Meta-Analysis

Hepatitis delta virus (HDV) has been associated with acute or chronic hepatitis in Latin America, but there is no prevalence study covering South American countries. This meta-analysis aimed to estimate anti-HDV prevalence through a systematic review of published articles in English, Portuguese and Spanish until December 2017. Searches were conducted in Health Virtual Library, Capes, Lilacs, PubMed, and SciELO, according to defined criteria regarding participant selection and geographical setting. Study quality was assessed using the GRADE guidelines. Pooled anti-HDV prevalence was calculated using the DerSimonian-Laird random-effects model with Freeman-Tukey double arcsine transformation. Out of the 405 identified articles, only 31 met the eligibility criteria for inclusion in the meta-analysis. In South America, pooled anti-HDV prevalence among hepatitis B virus carriers was 22.37% (95% confidence interval: 13.72-32.26), though it appeared less frequently in some countries and populations, according to the data collection date. The findings indicated significant successive reductions in anti-HDV prevalence over thirty years. However, there was a scarcity of HDV epidemiological studies outside the Amazon Basin, notably in the Southwest continent and absence of target population standardization. There was a high HDV prevalence in South American countries, despite differences in methodological characteristics and outcomes, highlighting a drastic decline in the last decades. Future studies should identify HDV prevalence estimates in other regions of the continent and identify risk factors.

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.

Molecular epidemiology of hepatitis delta and hepatitis B viruses circulating in two major provinces (East and North-West) of Pakistan

OBJECTIVES

HBV and HDV are major public health problems with millions affected globally and Pakistan accounts for a significant proportion of the global Hepatitis burden. This cross sectional study was designed to assess the general epidemiological and virological features of HBV and HDV in the Punjab and Khyber Pakhtunkhawa (KP) provinces of Pakistan.

METHODS

A total of 1890 HBV patients from March 2016 to May 2017 were recruited in the study and the presence of HDV was retrospectively evaluated in all participants. Most participants were young adults (from 21 to 30 years). Genotyping was based on PCR amplification using primers specific for HBV genotypes A-F, and HDV. 405 nucleotide fragments of HDV were sequenced. MEGA was used for phylogenetic analysis.

RESULTS

Overall prevalence of HBV was 14.08% (266/1890). Higher prevalence was observed in males (66.85%) as compared to females (33.15%). Co-infection of HDV was found in 39 (14.66%) patients. HBV genotype-D was prevalent in dual infections followed by HDV/A (p < 0.05).While HDV genotype 1 was predominant in all HBV positive samples. Compared to Punjab, coinfection was higher in KP (14.3% versus15.2%; p < 0.05).

CONCLUSION

The prevalence of HBV and HDV is high in Pakistan. The description of HBV and HDV genotypes circulating in East and North-West Pakistan can contribute to a better understanding of their relevance in regional epidemics. These infections are highly endemic in the KP, where their control is confounded by its vast territorial dimension with small, hard-to-reach municipalities and diverse ethnic populations.

Hepatitis D infection in Brazil: Prevalence and geographical distribution of anti-Delta antibody

In Brazil, the Amazon Basin is endemic for hepatitis D virus (HDV) infection; however, studies in other regions of the country are scarce. This study aims to map the seroepidemiological situation of anti-Delta antibodies in chronic hepatitis B carriers in all five Brazilian geographic regions. Serum samples from 1240 HBsAg positive individuals (55.4% men; mean age 43.1 ± 13.4 years) from 24 of 26 Brazilian states were tested for the presence of anti-Delta antibodies using a commercial immunoassay. Anti-Delta antibodies were detected in 40 samples (3.2%; 52.5% female; mean age of 38.1 ± 13.8 years). Age less than 20 years was significantly associated with anti-HDV positivity (P < 0.001). The distribution of anti-Delta differed markedly in the diverse regions of the country. The highest prevalence of anti-HDV was found in the North (8.5%; P < 0.001), followed by Central West (2.5%), Southeast (1.7%), Northeast (0.8%), and South (0.0%). Anti-Delta antibodies were detected in 12 states, but more than 60% of the positive cases were observed in two states, Amazonas and Acre, located in the western portion of the Amazon region. The overall HDV prevalence of 3.2% emphasizes that HDV is far from being a disease under control in Brazil. Despite the low HDV prevalence in non-endemic regions, this infection persists as a major concern in two states (Acre and Amazonas) in the north of the country, indicating that a continuous epidemiological surveillance program should be implemented in all Brazilian regions.