Hepatitis B virus (HBV)/hepatitis D virus (HDV) coinfection in outbreaks of acute hepatitis in the Peruvian Amazon basin: the roles of HDV genotype III and HBV genotype F

Prevalence and determinants of hepatitis delta virus infection among HIV/hepatitis B-coinfected adults in care in the United States

Hepatitis delta virus (HDV) infection increases the risk of liver complications compared to hepatitis B virus (HBV) alone, particularly among persons with human immunodeficiency virus (HIV). However, no studies have evaluated the prevalence or determinants of HDV infection among people with HIV/HBV in the US. We performed a cross-sectional study among adults with HIV/HBV coinfection receiving care at eight sites within the Center for AIDS Research Network of Integrated Clinical Systems (CNICS) between 1996 and 2019. Among patients with available serum/plasma specimens, we selected the first specimen on or after their initial HBV qualifying test. All samples were tested for HDV IgG antibody and HDV RNA. Multivariable log-binomial generalized linear models were used to estimate prevalence ratios (PRs) with 95% CIs of HDV IgG antibody-positivity associated with determinants of interest (age, injection drug use [IDU], high-risk sexual behaviour). Among 597 adults with HIV/HBV coinfection in CNICS and available serum/plasma samples (median age, 43 years; 89.9% male; 52.8% Black; 42.4% White), 24/597 (4.0%; 95% CI, 2.4%-5.6%) were HDV IgG antibody-positive, and 10/596 (1.7%; 95% CI, 0.6%-2.7%) had detectable HDV RNA. In multivariable analysis, IDU was associated with exposure to HDV infection (adjusted PR = 2.50; 95% CI, 1.09-5.74). In conclusion, among a sample of adults with HIV/HBV coinfection in care in the US, 4.0% were HDV IgG antibody-positive, among whom 41.7% had detectable HDV RNA. History of IDU was associated with exposure to HDV infection. These findings emphasize the importance of HDV testing among persons with HIV/HBV coinfection, especially those with a history of IDU.

Diagnosis of HDV: From virology to non-invasive markers of fibrosis

Hepatitis D viral infection in humans is a disease that requires the establishment of hepatitis B, relying on hepatitis B surface Ag and host cellular machinery to replicate and propagate the infection. Since its discovery in 1977, substantial progress has been made to better understand the hepatitis D viral life cycle, pathogenesis and modes of transmission along with expanding on clinical knowledge related to prevention, diagnosis, monitoring and treatment. The availability of serologic diagnostic assays for hepatitis D infection has evolved over time with current widespread availability, improved detection and standardized reporting. With human migration, the epidemiology of hepatitis D infection has changed over time. Thus, the ability to use diagnostic assays remains essential to monitor the global impact of hepatitis D infection. Separately, while liver biopsy remains the gold standard for the staging of this rapidly progressive and severe form of chronic viral hepatitis, there is an unmet need for clinical monitoring of chronic hepatitis D infection for management of progressive disease. Thus, exploration of the utility of non-invasive fibrosis markers in hepatitis D is ongoing. In this review, we discuss the virology, the evolution of diagnostics and the development of non-invasive markers for the detection and monitoring of fibrosis in patients with hepatitis D infection.

Development of quantitative multiplex RT-qPCR one step assay for detection of hepatitis delta virus

Hepatitis Delta is a disease caused by exposure to hepatitis B (HBV) and hepatitis D (HDV) viruses, usually with a more severe clinical outcome when compared to an HBV monoinfection. To date, the real prevalence of HDV infection is underestimated and detection methods are poorly available, especially in more endemic regions. Therefore, a one-step RT-qPCR method for quantification of HDV-RNA was developed. Biological samples were selected between 2017 and 2023 from patients at the Ambulatório Especializado em Hepatites Virais of the Centro de Pesquisa em Medicina Tropical de Rondônia and Serviço de Assistência Especializada and underwent the test developed by this study and a second quantitative RT-qPCR assay. The slope of the initial quantitative assay was - 3.321 with an efficiency of 100.04% and amplification factor equal to 2. Analysis of the repeatability data revealed a Limit of Quantification of 5 copies/reaction and Limit of Detection (95%) of 2.83 copies per reaction. In the diagnostic sensitivity tests, there was an accuracy of 97.37% when compared to the reference test. This assay proved to be highly efficient and reproducible, making it a valuable tool to monitor hepatitis Delta patients and assess the risk of disease progression, as well as the effectiveness of treatment.

Systemic Inflammatory Molecules Are Associated with Advanced Fibrosis in Patients from Brazil Infected with Hepatitis Delta Virus Genotype 3 (HDV-3)

BACKGROUND AND AIMS

Hepatitis Delta virus (HDV) genotype 3 is responsible for outbreaks of fulminant hepatitis in Northeastern South America. This study investigates if systemic inflammatory molecules are differentially expressed in patients with advanced fibrosis chronically infected with Hepatitis Delta virusgenotype 3(HDV-3).

METHODS

Sixty-one patients from the north of Brazil coinfected with hepatitis B virus (HBV)/HDV-3 were analyzed. HDV quantification and genotyping were performed by semi-nested real-time polymerase chain reaction (RT-PCR) and restriction fragment length polymorphism (RFLP) methodologies. Ninety-two systemic inflammatory molecules (SIMs) were measured by Proximity Extension Assay (PEA) technology. The Shapiro-Wilk, Student's t-test, Mann-Whitney tests, and logistic regression analysis were used when appropriate.

RESULTS

The median age was 41 years, and all patients were HBeAg negative. Advanced fibrosis or cirrhosis was diagnosed by histological staging in 17 patients, while 44 presented with minimal or no fibrosis. Advanced necroinflammatory activity correlated positively with serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Established non-invasive fibrosis scores (APRI, FIB-4, and AST/ALT ratio) revealed low sensitivities and positive predictive values (PPVs) with an AUROC maximum of 0.586. Among the 92 SIMs analyzed, MCP.4, CCL19, EN.RAGE, SCF, and IL18 showed a positive correlation with fibrosis stage. A combined score including CCL19 and MCP.4 revealed a sensitivity of 81% and an odds ratio of 2.202 for advanced fibrosis.

CONCLUSIONS

Standard non-invasive fibrosis scores showed poor performance in HDV-3 infection. We here suggest that the determination of CCL19 and MCP.4 may be used to identify patients with advanced fibrosis. Moreover, this study gives novel insights into the immunopathogenesis of HDV-3 infection.

Epidemiology, presentation, and therapeutic approaches for hepatitis D infections

INTRODUCTION

Chronic Hepatitis D virus (HDV) infection remains an important global public health problem, with a changing epidemiological landscape over the past decade along with widespread implementation of hepatitis B vaccination and human migration. The landscape of HDV treatments has been changing, with therapies that have been under development for the last decade now in late stage clinical trials. The anticipated availability of these new therapies will hopefully replace the current therapies which are minimally effective.

AREAS COVERED

This narrative review discusses the clinical course, screening and diagnosis, transmission risk factors, epidemiology, current and investigational therapies, and liver transplantation in HDV. Literature review was performed using PubMed and ClinicalTrials.gov and includes relevant articles from 1977 to 2022.

EXPERT OPINION

HDV infection is an important global public health issue with a true prevalence that is still unknown. The distribution of HDV infection has changed globally with the availability of HBV vaccination and patterns of human migration. As HDV infection is associated with accelerated disease courses and poor outcomes, the global community needs to agree upon a uniform HDV screening strategy to understand the truth of global prevalence such that new therapies can target appropriate individuals as they become available in the future.

Different evolutionary dynamics of hepatitis B virus genotypes A and D, and hepatitis D virus genotypes 1 and 2 in an endemic area of Yakutia, Russia

Background

The geographic distribution of the hepatitis B virus (HBV) and the hepatitis D virus (HDV) genotypes is uneven. We reconstructed the temporal evolution of HBV and HDV in Yakutia, one of the regions of Russia most affected by HBV and HDV, in an attempt to understand the possible mechanisms that led to unusual for Russia pattern of viral genotypes and to identify current distribution trends.

Methods

HBV and HDV genotypes were determined in sera collected in 2018–2019 in Yakutia from randomly selected 140 patients with HBV monoinfection and 59 patients with HBV/HDV. Total 86 HBV and 88 HDV genomic sequences isolated in Yakutia between 1997 and 2019 were subjected to phylodynamic and philogeographic Bayesian analysis using BEAST v1.10.4 software package. Bayesian SkyGrid reconstruction and Birth–Death Skyline analysis were applied to estimate HBV and HDV population dynamics.

Results

Currently, HBV-A and HDV-D genotypes are prevalent in Yakutia, in both monoinfected and HDV-coinfected patients. Bayesian analysis has shown that the high prevalence of HBV-A in Yakutia, which is not typical for Russia, initially emerged after the genotype was introduced from Eastern Europe in the fifteenth century (around 600 (95% HPD: 50–715) years ago). The acute hepatitis B epidemics in the 1990s in Yakutia were largely associated with this particular genotype, as indicated by temporal changes in HBV-A population dynamics. HBV-D had a longer history in Yakutia and demonstrated stable population dynamics, indicating ongoing viral circulation despite vaccination. No correlation between HBV and HDV genotypes was observed for coinfected patients in Yakutia (r = − 0.016069332). HDV-2b circulates in Russia in Yakutia only and resulted from a single wave of introduction from Central Asia 135 years ago (95% HPD: 60–350 years), while HDV-1 strains resulted from multiple introductions from Europe, the Middle East, Central Asia, and different parts of Russia starting 180 years ago (95% HPD: 150–210 years) and continuing to the present day. The population dynamics of HDV-1 and HDV-2 show no signs of decline despite 20 years of HBV vaccination. The Birth–Death Skyline analysis showed an increase in the viral population in recent years for both HDV genotypes, indicating ongoing HDV epidemics.

Conclusions

Taken together, these data call for strict control of HBV vaccination quality and coverage, and implementation of HBV and HDV screening programs in Yakutia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07444-w.

Hepatitis B/D-Related Hepatocellular Carcinoma. A Clinical Literature Review

AIM

Given the current literature data, this article aims to shed light on the epidemiological and clinical effects of HBV, as well as its impact on the development of hepatocellular carcinoma (HCC).

METHODS

A review of the English language literature based on a MEDLINE (PubMed) database was searched. The keywords were cirrhosis, hepatocellular carcinoma, epidemiology, hepatitis delta virus, hepatitis B virus, and co-infection. All references from retrieved papers were reviewed systematically to find additional collection of reports.

RESULTS

The study has broadly confirmed the contribution of HDV viremia to liver disease and cirrhosis. However, uncertainty over the mechanism of action on HCC development remains. As the recent data has demonstrated, the HCC-HDV has a unique molecular profile which is distinct from that of HBV-HCC.

CONCLUSION

Owing to the dependence of HDV on HBV, it is not clear whether HCC is a consequence of the cumulative effect of both HBV and HDV, an effect of the underlying cirrhosis, or a direct oncogenic effect of HDV. Many questions concerning the oncogenic role of HDV remain unanswered. To better understand the role of HDV in carcinogenesis, studies at the molecular level that consider genotype differences should be increased. Multicenter, high-volume, and prospective studies that compare HBV/HDV co-infected and HBV-infected individuals will be pivotal in determining the oncogenic role of HDV.

Strong Replication Interference Between Hepatitis Delta Viruses in Human Liver Chimeric Mice

Background

Hepatitis D Virus (HDV) is classified into eight genotypes with distinct clinical outcomes. Despite the maintenance of highly conserved functional motifs, it is unknown whether sequence divergence between genotypes, such as HDV-1 and HDV-3, or viral interference mechanisms may affect co-infection in the same host and cell, thus hindering the development of HDV inter-genotypic recombinants. We aimed to investigate virological differences of HDV-1 and HDV-3 and assessed their capacity to infect and replicate within the same liver and human hepatocyte in vivo.

Methods

Human liver chimeric mice were infected with hepatitis B virus (HBV) and with one of the two HDV genotypes or with HDV-1 and HDV-3 simultaneously. In a second set of experiments, HBV-infected mice were first infected with HDV-1 and after 9 weeks with HDV-3, or vice versa. Also two distinct HDV-1 strains were used to infect mice simultaneously and sequentially. Virological parameters were determined by strain-specific qRT-PCR, RNA in situ hybridization and immunofluorescence staining.

Results

HBV/HDV co-infection studies indicated faster spreading kinetics and higher intrahepatic levels of HDV-3 compared to HDV-1. In mice that simultaneously received both HDV strains, HDV-3 became the dominant genotype. Interestingly, antigenomic HDV-1 and HDV-3 RNA were detected within the same liver but hardly within the same cell. Surprisingly, sequential super-infection experiments revealed a clear dominance of the HDV strain that was inoculated first, indicating that HDV-infected cells may acquire resistance to super-infection.

Conclusion

Infection with two largely divergent HDV genotypes could be established in the same liver, but rarely within the same hepatocyte. Sequential super-infection with distinct HDV genotypes and even with two HDV-1 isolates was strongly impaired, suggesting that virus interference mechanisms hamper productive replication in the same cell and hence recombination events even in a system lacking adaptive immune responses.

Hepatitis Delta Virus (HDV) and Delta-Like Agents: Insights Into Their Origin

Hepatitis delta virus (HDV) is a human pathogen, and the only known species in the genus Deltavirus. HDV is a satellite virus and depends on the hepatitis B virus (HBV) for packaging, release, and transmission. Extracellular HDV virions contain the genomic HDV RNA, a single-stranded negative-sense and covalently closed circular RNA molecule, which is associated with the HDV-encoded delta antigen forming a ribonucleoprotein complex, and enveloped by the HBV surface antigens. Replication occurs in the nucleus and is mediated by host enzymes and assisted by cis-acting ribozymes allowing the formation of monomer length molecules which are ligated by host ligases to form unbranched rod-like circles. Recently, meta-transcriptomic studies investigating various vertebrate and invertebrate samples identified RNA species with similarities to HDV RNA. The delta-like agents may be representatives of novel subviral agents or satellite viruses which share with HDV, the self-complementarity of the circular RNA genome, the ability to encode a protein, and the presence of ribozyme sequences. The widespread distribution of delta-like agents across different taxa with considerable phylogenetic distances may be instrumental in comprehending their evolutionary history by elucidating the transition from transcriptome to cellular circular RNAs to infectious subviral agents.

Hepatitis B virus genotypes in Brazil: Introduction and dissemination

Hepatitis B is a viral infectious disease highly spread worldwide with a long evolutionary history associated with human migrations through the continents and countries. Hepatitis B virus (HBV) was disseminated probably from Africa and diverged into ten genotypes (HBV-A to HBV-J) distributed around the world. In Brazil, almost all HBV genotypes were already reported, with a predominance of three ones: A (52.1%), D (36.8%), and F (7.7%). This review aimed to evaluate the introduction and dissemination of the main HBV genotypes and subgenotypes in Brazil over the last centuries to explain the current epidemic scenario. The highest frequency of HBV-A is a consequence of the introduction and spreading of HBV-A1 in the 16th to 19th centuries due to the African slave trade, but the more recent introduction of HBV-A2 from Europe also contributed to the current situation. HBV-D is the second most frequent genotype because it was consecutively introduced by migrations from Europe (mainly subgenotype D3, but also D2) and the Middle East (D1) in the 19th to 20th centuries. On contrary, HBV-F (F1a, F1b, F2a, F2b, F3, and F4) was disseminated by the Amerindians in all South American countries, including Brazil, by migrations inside the continent for more than three centuries ago. Other HBV genotypes are rare and eventually frequent in some human groups because of the dissemination by very specific epidemiological routes. In conclusion, the current scenario of the HBV epidemics is a consequence of the introduction and dissemination of some subgenotypes from the three main genotypes A, D, and F over the last five centuries.

In Vivo Models of HDV Infection: Is Humanizing NTCP Enough?

The discovery of sodium taurocholate co-transporting polypeptide (NTCP) as a hepatitis B (HBV) and delta virus (HDV) entry receptor has encouraged the development of new animal models of infection. This review provides an overview of the different in vivo models that are currently available to study HDV either in the absence or presence of HBV. By presenting new advances and remaining drawbacks, we will discuss human host factors which, in addition to NTCP, need to be investigated or identified to enable a persistent HDV infection in murine hepatocytes. Detailed knowledge on species-specific factors involved in HDV persistence also shall contribute to the development of therapeutic strategies.

HBV/HDV Co-Infection: Epidemiological and Clinical Changes, Recent Knowledge and Future Challenges

Several investigations have been published on Hepatitis Delta Virus (HDV) infection in recent years, from which we have drawn the salient data to provide readers with useful information to improve their knowledge on the subject. HDV genotypes 5–8 have been recently imported to Western countries from central Africa, whose clinical relevance deserves further investigation. Ongoing HDV replication has been identified as an independent predictor of progression to cirrhosis and HCC for patients with HDV chronic hepatitis (HDV-CH). Long-term treatments of HDV-CH with standard or pegylated interferon alfa (peg-IFN-α) have all been unsatisfactory, leading to a sustained virological response (SVR) only in 20–30% of patients treated, faced with a poor tolerability and frequent serious adverse reactions; the addition of HBV nucleo(s)tide analogues to peg-IFN- α did not improve the rate of SVR. The improved knowledge of the HDV life cycle has allowed the development of direct acting agents towards key-points of the HDV life cycle, namely bulevirtide, lonafarnib and nucleic acid polymers. Preliminary data have shown that these drugs are more effective than interferon-based therapies, but adverse reactions are also common, which however seem toned down in combination therapy with other antivirals.

Murine hepatocytes do not support persistence of Hepatitis D virus mono-infection in vivo

BACKGROUNDS & AIMS

As a result of the limited availability of in vivo models for hepatitis D virus (HDV), treatment options for HDV chronically infected patients are still scant. The discovery of sodium taurocholate cotransporting polypeptide (NTCP) as HDV entry receptor has enabled the development of new infection models.

AIM

To comparatively assess the efficacy and persistence of HDV mono-infection in murine and human hepatocytes in vivo.

METHODS

Mice with humanized NTCP (hNTCP^ed84-87 mice) were generated by editing amino acid residues 84-87 of murine NTCP in C57BL/6J mice. HDV infection was assessed in hNTCP^ed84-87 mice and in immune deficient uPA/SCID/beige (USB) mice, whose livers were reconstituted with human or murine (hNTCP^ed84-87 ) hepatocytes. Livers were analysed between 5 and 42 days post-HDV inoculation by qRT-PCR, immunofluorescence and RNA in situ hybridization (ISH).

RESULTS

hNTCP^ed84-87 mice could be infected with HDV genotype 1 or 3. ISH analysis demonstrated the presence of antigenomic HDV RNA positive murine hepatocytes with both genotypes, proving initiation of HDV replication. Strikingly, murine hepatocytes cleared HDV within 21 days both in immunocompetent hNTCP^ed84-87 mice and in immunodeficient USB mice xenografted with murine hepatocytes. In contrast, HDV infection remained stable for at least 42 days in human hepatocytes. Intrinsic innate responses were not enhanced in any of the HDV mono-infected cells and livers.

CONCLUSION

These findings suggest that in addition to NTCP, further species-specific factors limit HDV infection efficacy and persistence in murine hepatocytes. Identifying such species barriers may be crucial to develop novel potential therapeutic targets of HDV.

Epidemiology, Natural History, and Treatment of Hepatitis Delta Virus Infection in HIV/Hepatitis B Virus Coinfection

PURPOSE OF REVIEW

Limited data exist on the prevalence, determinants, and outcomes of hepatitis delta virus (HDV) infection among HIV/hepatitis B virus (HBV)-coinfected persons. This review provides current evidence on the epidemiology, natural history, and treatment of HDV infection in patients with HIV/HBV coinfection and highlights future research needs.

RECENT FINDINGS

Cross-sectional studies in Europe, Africa, South America, and Asia show that the prevalence of HDV among HIV/HBV-coinfected patients ranges from 1.2 to 25%. No studies have evaluated the prevalence of HDV infection among HIV/HBV-coinfected patients in the USA. HDV infection increases the risk of hepatic decompensation and hepatocellular carcinoma among HIV/HBV-coinfected patients. HDV treatment remains limited to pegylated interferon-alpha, which results in sustained virologic response in fewer than 25%. Data on the epidemiology, natural history, and treatment of HDV among HIV/HBV-coinfected persons remain limited. More research is needed to address these knowledge gaps in order to better manage HDV coinfection in HIV/HBV-coinfected patients.

Origin, HDV genotype and persistent viremia determine outcome and treatment response in patients with chronic hepatitis delta

BACKGROUND & AIMS

HDV infection causes severe chronic liver disease in individuals infected with HBV. However, the factors associated with poor prognosis are largely unknown. Thus, we aimed to identify prognostic factors in patients with HDV infection.

METHODS

The French National Reference Centre for HDV performed a nationwide retrospective study on 1,112 HDV-infected patients, collecting epidemiological, clinical, virological and histological data from the initial referral to the last recorded follow-up.

RESULTS

The median age of our cohort was 36.5 (29.9-43.2) years and 68.6% of our cohort were male. Most patients whose birthplace was known were immigrants from sub-Saharan Africa (52.5%), southern and eastern Europe (21.3%), northern Africa and the Middle East (6.2%), Asia (5.9%) and South America (0.3%). Only 150 patients (13.8%) were French native. HDV load was positive in 659 of 748 tested patients (88.1%). HDV-1 was predominant (75.9%), followed by sub-Saharan genotypes: HDV-5 (17.6%), HDV-7 (2.9%), HDV-6 (1.8%) and HDV-8 (1.6%). At referral, 312 patients (28.2%) had cirrhosis, half having experienced at least 1 episode of hepatic decompensation. Cirrhosis was significantly less frequent in African than in European patients regardless of HDV genotype. At the end of follow-up (median 3.0 [0.8-7.2] years), 48.8% of the patients had developed cirrhosis, 24.2% had ≥1 episode(s) of decompensation and 9.2% had hepatocellular carcinoma. European HDV-1 and African HDV-5 patients were more at risk of developing cirrhosis. Persistent replicative HDV infection was associated with decompensation, hepatocellular carcinoma and death. African patients displayed better response to interferon therapy than non-African patients (46.4% vs. 29.1%, p <0.001). HDV viral load at baseline was significantly lower in responders than in non-responders.

CONCLUSION

Place of birth, HDV genotype and persistent viremia constitute the main determinants of liver involvement and response to treatment in chronic HDV-infected patients.

LAY SUMMARY

Chronic liver infection by hepatitis delta virus (HDV) is the most severe form of chronic viral hepatitis. Despite the fact that at least 15-20 million people are chronically infected by HDV worldwide, factors determining the severity of liver involvement are largely unknown. By investigating a large cohort of 1,112 HDV-infected patients followed-up in France, but coming from different areas of the world, we were able to determine that HDV genotype, place of birth (reflecting both viral and host-related factors) and persistent viremia constitute the main determinants of liver involvement and response to treatment.

The evolution and clinical impact of hepatitis B virus genome diversity

The global burden of hepatitis B virus (HBV) is enormous, with 257 million persons chronically infected, resulting in more than 880,000 deaths per year worldwide. HBV exists as nine different genotypes, which differ in disease progression, natural history and response to therapy. HBV is an ancient virus, with the latest reports greatly expanding the host range of the Hepadnaviridae (to include fish and reptiles) and casting new light on the origins and evolution of this viral family. Although there is an effective preventive vaccine, there is no cure for chronic hepatitis B, largely owing to the persistence of a viral minichromosome that is not targeted by current therapies. HBV persistence is also facilitated through aberrant host immune responses, possibly due to the diverse intra-host viral populations that can respond to host-mounted and therapeutic selection pressures. This Review summarizes current knowledge on the influence of HBV diversity on disease progression and treatment response and the potential effect on new HBV therapies in the pipeline. The mechanisms by which HBV diversity can occur both within the individual host and at a population level are also discussed.

Comment: Mis-Genotyping of Some Hepatitis D Virus Genotype 2 and 5 Sequences Using HDVdb

Evidence that Hepatitis D virus (HDV) genotype is involved in HDV infection pathogenesis is increasing. Indeed, HDV genotypes have been shown to be linked to different outcomes in terms of liver fibrosis and treatment response. Herein, we show that the promising HDVdb genotyping tool available online can lead to wrong genotyping results. The current HDVdb algorithm should be carefully considered as a “beta-version” and warrants algorithm core corrections, as soon as possible, for an optimal and beneficial use.

Noninvasive Models for Predicting Liver Fibrosis in Individuals with Hepatitis D Virus/Hepatitis B Virus Coinfection in the Brazilian Amazon Region

Hepatitis D virus (HDV) genotype III is endemic in the western Amazon basin and is considered to cause the most severe form of chronic viral hepatitis. Recently, noninvasive fibrosis scores to determine the stage of liver fibrosis have been evaluated in individuals positive for HDV genotype I, but their utility in HDV genotype III-positive patients is unknown. In this retrospective study conducted in an outpatient viral hepatitis referral clinic in the Brazilian Amazon region, the aspartate aminotransferase (AST) to Aspartate aminotransferase to Platelet Ratio Index (APRI) and Fibrosis Index for Liver Fibrosis (FIB-4) values were calculated and compared with histological fibrosis stages. Among the 50 patients analyzed, the median age at liver biopsy was 35.6 years, 66% were male, and all had compensated liver disease. Histological staging revealed fibrosis stages 0, 1, 2, 3, and 4 in four (8%), eight (16%), 11 (22), 11 (22%), and 16 (32%) patients, respectively. The area under the receiver operating curve (AUROC) of AST-to-alanine aminotransferase (ALT) ratio, APRI, and FIB-4 for detection of significant fibrosis (F ≥ 2) was 0.550 (P = 0.601), 0.853 (P < 0.001), and 0.853 (P < 0.0001), respectively. Lower AUROC values were obtained for cirrhosis: the AST-to-ALT ratio was 0.640 (P = 0.114), APRI was 0.671 (P = 0.053), and FIB-4 was 0.701 (P = 0.023). The optimal cutoff value for significant fibrosis for APRI was 0.708 (sensitivity 84% and specificity 92%) and for FIB-4 was 1.36 (sensitivity 76% and specificity 92%). Aspartate aminotransferase to Platelet Ratio Index and FIB-4 were less useful to predict cirrhosis. In contrast to recent reports from Europe and North America, both APRI and FIB-4 may identify significant fibrosis in HDV-III-infected patients from northwestern Brazil.

HDV infection in immigrant populations

AIMS

Little data have been published so far on the epidemiological aspects of hepatitis D virus (HDV) infection in immigrant populations and even poorer is the information on the virological, phylogenetic, and clinical aspects of this infection in these populations. This review article, aimed primarily at physicians caring for immigrants, summarizes the information available on HDV infection and analyzes data on this topic concerning the immigrant populations.

METHODS AND RESULTS

The prevalence of HDV infection in HBsAg-positive immigrants varies according to the country of origin. For example, in immigrants from sub-Saharan Africa, this prevalence is higher in those born in Equatorial Guinea (24.4%) than those from other African countries (10.3%). The epidemiological impact of HDV infection linked to migratory flows is a function of the different endemicity between countries of origin and countries in which a new existence has been established. This impact is high when immigrants from areas endemic to HDV infection (eg, Equatorial Guinea) settle in areas of low endemicity (eg, Germany or England, with a prevalence of around 4%), while the impact is lesser or nonexistent if the migratory flows are directed toward countries with intermediate endemicity (eg, Italy and Greece, with a prevalence of around 10%).

CONCLUSION

This impact of immigration on HDV epidemiology can be strong when HDV endemicity is high in the country of origin and low in the host country and slight when immigrants move to high or medium endemic countries.

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.

Characterization of hepatitis delta virus strains spreading in Abuja, Nigeria

Hepatitis delta virus (HDV) is responsible for the most severe form of liver disease in humans. So far, eight genotypes (HDV-1 to -8) have been individualized worldwide. Little is known about HDV strains that spread in Nigeria. HDV genotyping was performed in 15 anti-HDV positive samples from a cohort of 306 hepatitis B virus (HBV)-infected patients in Abuja (Nigeria). Phylogenetic analyses revealed 90% were HDV-1, two among them clustering with European/Asian HDV-1, the remaining one being HDV-6. It was also found that two members of a couple superinfected with the same HDV strain, were enveloped by two different HBV strains of genotype E.

Treating chronic hepatitis delta: The need for surrogate markers of treatment efficacy

Chronic hepatitis delta represents the most severe form of chronic viral hepatitis. The current treatment of hepatitis delta virus (HDV) infection consists of the use of interferons and is largely unsatisfactory. Several new compounds are currently in development for the treatment of HDV infection. However, surrogate markers that can be used to develop clinical endpoints in HDV infection are not well defined. In the current manuscript, we aimed to evaluate the existing data on treatment of HDV infection and to suggest treatment goals (possible "trial endpoints") that could be used across different clinical trials.

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.

Non-F HBV/HDV-3 coinfection is associated with severe liver disease in Western Brazilian Amazon

The clinical outcome of hepatitis B virus (HBV) infection may be related to host and viral genetic factors, as well as to the type of infection (monoinfection and coinfection). To analyze the distribution/combination of HBV/hepatitis D virus (HDV) genotypes and the associated clinical characteristics, 409 serum samples from patients with chronic HBV (94 of them coinfected by HDV) followed at the Viral Hepatitis Referral Center of Rio Branco, Brazil were enrolled. HBV DNA and HDV RNA were amplified, respectively, by polymerase chain reaction (PCR) and nested PCR using specific primers in the PreC/C region and the S gene, and by reverse-transcription PCR and seminested PCR using specific primers in the delta antigen region and sequenced. The proportion of women (56.1%) was significantly higher than males in this cohort ( P < 0.01). Women were significantly younger (39.8 years; 8-77 years) than males (44.7 years; 12-79 years; P < 0.01). Sixty-eight (18%) patients were infected with HBV-F genotype and 264 (69.8%) with HBV/non-F genotypes. Coinfection by HDV was detected in 23.9% (94 of 409) of this population and was more frequent in male (54.2%, 51 of 94) than in female patients (44.7%, 42 of 94; P = 0.015). HDV-3 was the most prevalent (88.9%) genotype. Almost 70% of HDV-3 coinfected patients were infected with HBV/non-F genotypes. Severe liver disease was diagnosed in 41 patients, 60.9% (25 of 41) of them coinfected with HDV. HBV/HDV coinfection was associated with male sex, age above 30 years, severe liver disease, and increased alanine aminotransferase levels. HBV/HDV-3 coinfection is associated with severe liver disease, in Rio Branco, Brazil.

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.

A 79-year-old Woman with Acute Hepatitis B Caused by the Infection of Subgenotype D1 Hepatitis B Virus in Japan: A Case Study

A 79-year-old Japanese woman was diagnosed with acute hepatitis B based on laboratory tests showing positivity for IgM-class antibody against hepatitis B virus (HBV) core and hepatitis B surface antigen (HBsAg) as well as elevated transaminases. A phylogenetic analysis revealed that the HBV strain obtained from the patient belonged to genotype D/subgenotype D1, similar to strains circulating in foreign countries but different from those in Japan. The clinical course was favorable. HBsAg became negative within 10 weeks after the onset. To our knowledge, this is the first report of acute hepatitis B caused by subgenotype D1 HBV in Japan.

Early-onset liver cancer in South America associates with low hepatitis B virus DNA burden

In Peru, hepatocellular carcinoma (HCC) arises in young non-cirrhotic patients. Hepatitis B virus (HBV) is suspected to be the prominent etiological agent. We thus performed a comprehensive molecular study of HBV infection in 65 Peruvian HCC patients. Only 51% were considered as persistently infected at the onset. HBV DNA was found by PCR in the tumor and/or matched non-tumor liver tissues in more than 80% of cases (n = 53/65). HBV DNA was significantly more abundant in livers of younger patients than in those of the older ones. We consistently observed low viral DNA burden (0.1–6.5 copies for 100 cells), with viral genomes in younger patients displaying higher proportion of mutations at di-pyrimidines (TpT and CpC, P = 0.006). A drastic activation of multiple DNA repair pathways in tumors of younger patients was observed. Our observations clearly challenge the current vision that associates high HBV DNA load with earlier tumor development. We concluded that in Peru, and maybe in other populations with Americas’ indigenous ancestry, HBV-associated liver tumorigenesis might differ significantly from that generally observed in the rest of the world. Procedures used to screen for HCC development in subjects at risk should be adapted to the local situation.

High prevalence of hepatitis delta virus in Cameroon

Hepatitis delta virus (HDV), a satellite virus of hepatitis B virus (HBV), infects an estimated 15–20 million people worldwide and confers a greater risk for accelerated progression to liver disease. However, limited HDV surveillance data are available in sub-Saharan Africa where HDV diversity is high. To determine the prevalence and diversity of HDV in Cameroon, serological and molecular characterization was performed on 1928 HBsAg positive specimens selected from retrospective viral surveillance studies conducted in Cameroon from 2010–2016. Samples were screened for HDV antibodies on the Abbott ARCHITECT instrument and for HDV RNA on the Abbott m2000 instrument by research assays. HDV positive specimens with sufficient viral load were selected for genomic sequencing. The seroprevalence of HDV in HBsAg positive samples from Cameroon was 46.73% [95% CI; 44.51–48.96%], with prevalence of active HDV infection being 34.2% [95% CI; 32.09–36.41%]. HDV genotypes 1, 6, 7 and 8 were identified amongst N = 211 sequences, including N = 145 genomes. HDV prevalence is high within the study cohort, indicating that a large portion of HBV infected individuals in Cameroon are at elevated risk for severe hepatitis and death. Collectively, these results emphasize the need for HBV vaccination and HDV testing in HBsAg positive patients in Cameroon.

Hepatitis delta virus and hepatocellular carcinoma: an update

Hepatitis delta virus (HDV) is a defective RNA virus that depends on the presence of hepatitis B virus (HBV) for the creation of new virions and propagation of the infection to hepatocytes. Chronic infection with HDV is usually associated with a worsening of HBV infection, leading more frequently to cirrhosis, increased risk of liver decompensation and hepatocellular carcinoma (HCC) occurrence. In spite of a progressive declining prevalence of both acute and chronic HDV infection observed over several years, mainly due to increased global health policies and mass vaccination against HBV, several European countries have more recently observed stable HDV prevalence mainly due to migrants from non-European countries. Persistent HDV replication has been widely demonstrated as associated with cirrhosis development and, as a consequence, development of liver decompensation and occurrence of HCC. Several treatment options have been attempted with poor results in terms of HDV eradication and improvement of long-term prognosis. A global effort is deemed urgent to enhance the models already existing as well as to learn more about HDV infection and correlated tumourigenesis mechanisms.

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.

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

BACKGROUND & AIMS

Chronic hepatitis D (delta) is a major global health burden. Clinical and virological characteristics of patients with hepatitis D virus (HDV) infection and treatment approaches in different regions world-wide are poorly defined.

METHODS

The Hepatitis Delta International Network (HDIN) registry was established in 2011 with centres in Europe, Asia, North- and South America. Here, we report on clinical/ virological characteristics of the first 1576 patients with ongoing or past HDV infection included in the database until October 2016 and performed a retrospective outcome analysis. The primary aim was to investigate if the region of origin was associated with HDV replication and clinical outcome.

RESULTS

The majority of patients was male (n = 979, 62%) and the mean age was 36.7 years (range 1-79, with 9% of patients younger than 20 years). Most patients were HBeAg-negative (77%) and HDV-RNA positive (85%). Cirrhosis was reported in 48.7% of cases which included 13% of patients with previous or ongoing liver decompensation. Hepatocellular carcinoma (HCC) developed in 30 patients (2.5%) and 44 (3.6%) underwent liver transplantation. Regions of origin were independently associated with clinical endpoints and detectability of HDV RNA. Antiviral therapy was administered to 356 patients with different treatment uptakes in different regions. Of these, 264 patients were treated with interferon-a and 92 were treated with HBV-Nucs only.

CONCLUSIONS

The HDIN registry confirms the severity of hepatitis delta but also highlights the heterogeneity of patient characteristics and clinical outcomes in different regions. There is an urgent need for novel treatment options for HDV infection.

Elevated serum β2-microglobulin in individuals coinfected with hepatitis B and hepatitis D virus in a rural settings in Southwest Nigeria

OBJECTIVE

Coinfection of hepatitis B virus (HBV) with hepatitis D virus (HDV) has being reported to increase severity of progression to hepatocellular carcinoma (HCC) and liver cirrhosis (LC). Beta microglobulin (2βM) which is present on the surfaces of blood cells in acceptable levels is a tumor marker which may become elevated in disease conditions. This study hence observed the prevalence of HBV and HDV coinfection in a rural population and their 2βM concentration.

RESULTS

Of the 368 samples, 66 (17.9%) were positive to hepatitis B surface antigen (HBsAg) and 33 (50%) were coinfected with HDV, 8 (2.1%) were monoinfected with HDV. 2βM concentration increased beyond the normal level in individuals coinfected with HBV and HDV as compared with the monoinfected individuals. Coinfection resulted in the increased concentration of 2βM in HBV and HDV coinfection and the likelihood of progression to HCC and LC may not be ruled out. Monoinfection with HDV also had high 2βM concentration but this is due to having being infected with a non-detected HBV or chronic infection in which HBV is clearing.

Hepatitis delta: virological and clinical aspects

There are an estimated 400 million chronic carriers of HBV worldwide; between 15 and 20 million have serological evidence of exposure to HDV. Traditionally, regions with high rates of endemicity are central and northern Africa, the Amazon Basin, eastern Europe and the Mediterranean, the Middle East and parts of Asia. There are two types of HDV/HBV infection which are differentiated by the previous status infection by HBV for the individual. Individuals with acute HBV infection contaminated by HDV is an HDV/HBV co-infection, while individuals with chronic HBV infection contaminated by HDV represent an HDV/HBV super-infection. The appropriate treatment for chronic hepatitis delta is still widely discussed since it does not have an effective drug. Alpha interferon is currently the only licensed therapy for the treatment of chronic hepatitis D. The most widely used drug is pegylated interferon but only approximately 25% of patients maintain a sustained viral response after 1 year of treatment. The best marker of therapeutic success would be the clearance of HBsAg, but this data is rare in clinical practice. Therefore, the best way to predict a sustained virologic response is the maintenance of undetectable HDV RNA levels.

Recent advances in managing hepatitis D

Hepatitis D virus (HDV) infection leads to the most severe form of chronic viral hepatitis and requires the attention of a liver specialist. In this review, I will recapitulate recent advances in the management of HDV, present background information on HDV infection as well as current chronic hepatitis D treatment, briefly examine the HDV life cycle and discuss new management strategies.

Hepatitis delta virus: insights into a peculiar pathogen and novel treatment options

Chronic hepatitis D is the most severe form of viral hepatitis, affecting ∼20 million HBV-infected people worldwide. The causative agent, hepatitis delta virus (HDV), is a unique human pathogen: it is the smallest known virus; it depends on HBV to disseminate its viroid-like RNA; it encodes only one protein (HDAg), which has both structural and regulatory functions; and it replicates using predominantly host proteins. The failure of HBV-specific nucleoside analogues to suppress the HBV helper function, and the limitations of experimental systems to study the HDV life cycle, have impeded the development of HDV-specific drugs. Thus, the only clinical regimen for HDV is IFNα, which shows some efficacy but long-term virological responses are rare. Insights into the receptor-mediated entry of HDV, and the observation that HDV assembly requires farnesyltransferase, have enabled novel therapeutic strategies to be developed. Interference with entry, for example through blockade of the HBV-HDV-specific receptor sodium/taurocholate cotransporting polypeptide NTCP by Myrcludex B, and inhibition of assembly by blockade of farnesyltransferase using lonafarnib or nucleic acid polymers such as REP 2139-Ca, have shown promising results in phase II studies. In this Review, we summarize our knowledge of HDV epidemiology, pathogenesis and molecular biology, with a particular emphasis on possible future developments.

Is Hepatitis Delta infections important in Brazil?

Background

The Hepatitis Delta Virus (HDV) can increase the incidence of fulminant hepatitis. For this infection occurs, the host must also be infected with Hepatitis B Virus. Previous studies demonstrated the endemicity and near exclusivity of this infection in the Amazon region, and as a consequence of the difficulty in accessing this area we used dried blood spots (DBS) in sample collection. The aims of this study were to investigate the presence of recombination, to analyze the epidemiology, ancestry and evolutionary pressures on HDV in Brazil.

Methods

Blood samples from 50 individuals were collected using dried-blood spots (DBS 903, Whatman), and sent via regular mail to Retrovirology Laboratory from Federal University of São Paulo, where the samples were processed. In the analysis the following software were used: PhyML, RDP, BEAST, jModelTest and CODEML.

Results

Our results confirm the prevalence of HDV-3 in the Amazon region of Brazil, with the absence of inter-genotypic recombination. It was identified a positive selection in probable epitopes of HDV on B lymphocytes that might indicate that the virus is changing to escape the humoral response of the host. The analysis of the time of the most common ancestor demonstrated the exponential growth of this virus in late 1970s that lasted until 1995, after which it remained constant. It was also observed a probable founder effect in two cities, which demonstrate the need to focus on prevention methods against HBV/HDV infection.

Conclusion

We confirmed the prevalence of HDV-3 in the Amazon region of Brazil, without inter-genotypic recombination. The analysis of the time of the most common ancestor showed that this infection remain constant in the studied area. Taking into account the probable founder effect established in the cities of Rio Branco and Porto Velho, a focus on preventive methods is recommended against these infections.

High prevalence of HBV/A1 subgenotype in native south Americans may be explained by recent economic developments in the Amazon

Native American populations present the highest prevalence of Hepatitis B Virus (HBV) infection in the Americas, which may be associated to severe disease outcomes. Ten HBV genotypes (A–J) have been described, displaying a remarkable geographic structure, which most likely reflects historic patterns of human migrations. In this study, we characterize the HBV strains circulating in a historical sample of Native South Americans to characterize the historical viral dynamics in this population. The sample consisted of 1070 individuals belonging to 38 populations collected between 1965 and 1997. Presence of HBV DNA was checked by quantitative real-time PCR, and determination of HBV genotypes and subgenotypes was performed through sequencing and phylogenetic analysis of a fragment including part of HBsAg and Pol coding regions (S/Pol). A Bayesian Skyline Plot analysis was performed to compare the viral population dynamics of HBV/A1 strains found in Native Americans and in the general Brazilian population. A total of 109 individuals were positive for HBV DNA (~ 10%), and 70 samples were successfully sequenced and genotyped. Subgenotype A1 (HBV/A1), related to African populations and the African slave trade, was the most prevalent (66–94%). The Skyline Plot analysis showed a marked population expansion of HBV/A1 in Native Americans occurring more recently (1945–1965) than in the general Brazilian population. Our results suggest that historic processes that contributed to formation of HBV/A1 circulating in Native American are related with more recent migratory waves towards the Amazon basin, which generated a different viral dynamics in this region.

Investigation of the roles of trace elements during hepatitis C virus infection using protein-protein interactions and a shortest path algorithm

BACKGROUND

Hepatitis is a type of infectious disease that induces inflammation of the liver without pinpointing a particular pathogen or pathogenesis. Type C hepatitis, as a type of hepatitis, has been reported to induce cirrhosis and hepatocellular carcinoma within a very short amount of time. It is a great threat to human health. Some studies have revealed that trace elements are associated with infection with and immune rejection against hepatitis C virus (HCV). However, the mechanism underlying this phenomenon is still unclear.

METHODS

In this study, we aimed to expand our knowledge of this phenomenon by designing a computational method to identify genes that may be related to both HCV and trace element metabolic processes. The searching procedure included three stages. First, a shortest path algorithm was applied to a large network, constructed by protein-protein interactions, to identify potential genes of interest. Second, a permutation test was executed to exclude false discoveries. Finally, some rules based on the betweenness and associations between candidate genes and HCV and trace elements were built to select core genes among the remaining genes.

RESULTS

12 lists of genes, corresponding to 12 types of trace elements, were obtained. These genes are deemed to be associated with HCV infection and trace elements metabolism.

CONCLUSIONS

The analyses indicate that some genes may be related to both HCV and trace element metabolic processes, further confirming the associations between HCV and trace elements. The method was further tested on another set of HCV genes, the results indicate that this method is quite robustness.

GENERAL SIGNIFICANCE

The newly found genes may partially reveal unknown mechanisms between HCV infection and trace element metabolism. This article is part of a Special Issue entitled "System Genetics" Guest Editor: Dr. Yudong Cai and Dr. Tao Huang.

Hepatitis D virus and hepatitis B virus infection in Amerindian communities of the Amazonas state, Colombia

BACKGROUND

In Colombia, cases of Hepatitis D virus (HDV) infection have been officially described since 1985 mainly in Amerindian population from Sierra Nevada de Santa Marta (North Caribbean Coast), Uraba (North West), and Amazon (South East). The last official report of a clinical case of HDV infection in Colombia was registered in 2005.

OBJECTIVES

The aims of this study were to identify cases of HDV and/or Hepatitis B virus (HBV) infection in asymptomatic Amerindians from Amazonas state, South East Colombia, and to describe the circulating viral genotypes in this population.

STUDY DESIGN

The study population was recruited in 19 Amerindian communities in the Amazonas state. Individuals over 18 years old were screened by rapid test for Hepatitis B surface Antigen (HBsAg). Blood samples obtained from individuals positives for HBsAg in the rapid-test assay were analyzed for HBsAg, anti-HBc, anti-HDV IgM/IgG by ELISA. The detection of HBV DNA and HDV RNA was performed by PCR amplification. The viral genotype was determined by sequencing and phylogenetic analysis.

RESULTS

A total of 23/861 individuals were positive for HBsAg detection by rapid test. Serological and/or molecular markers of HDV infection were demonstrated in 43.5 % (10/23) of samples from Amerindians. The phylogenetic analysis demonstrated the exclusive circulation of HBV subgenotype F1b of and HDV 3 in this population.

CONCLUSIONS

A high frequency of HBV/HDV infection was found in Amerindian population from Amazonas State, Colombia (43.5 %, 10/23). Nine cases were identified in a population of 861 asymptomatic Amerindian individuals; one symptomatic case (with diagnosis of end-stage hepatic disease) was also identified in the study. The circulation of HDV 3 and HBV subgenotype F1b suggests a constant flow of these viral genotypes as a result of the interaction of the Amerindian populations from Amazon basin. Further studies are necessary to confirm whether HBV subgenotype F1b is the prevalent in the population from South East region in Colombia.

Therapy of Delta Hepatitis

Delta hepatitis is the less frequently encountered but most severe form of viral hepatitis. Acute delta hepatitis, as a result of coinfection with hepatitis B and hepatitis delta, is rare, but may lead to fulminant hepatitis, and no therapy exists for this form. Chronic delta hepatitis (CDH) mostly develops as a result of superinfection of a hepatitis B surface antigen (HBsAg) carrier with hepatitis delta virus (HDV). In general, HDV is the dominant virus. However, a dynamic shift of the dominant virus may occur with time in rare instances, and hepatitis B virus (HBV) may become the dominant virus, at which time nucleos(t)ide analog therapy may be indicated. Otherwise, the only established management of CDH consists of conventional or pegylated interferon therapy, which has to be administered at doses used for hepatitis B for a duration of at least 1 year. Posttreatment week-24 virologic response is the most widely used surrogate marker of treatment efficacy, but it does not represent a sustained virologic response, and late relapse can occur. As an easy-to-use simple serological test, anti-HDV-immunoglobulin M (IgM) correlates with histological inflammatory activity and clinical long-term outcome; however, it is not as sensitive as HDV RNA in assessing treatment response. No evidence-based rules for treating CDH exist, and treatment duration needs to be individualized based on virologic response at end of treatment or end of follow-up. Effective treatment may decrease liver-related complications, such as decompensation or liver-related mortality. In patients with decompensated cirrhosis, interferons are contraindicated and liver transplantation has to be considered. Alternative treatment options are an urgent need in CDH. New treatment strategies targeting different steps of the HDV life cycle, such as hepatocyte entry inhibitors or prenylation inhibitors, are emerging and provide hope for the future.

Genomic Diversity of Hepatitis B Virus Infection Associated With Fulminant Hepatitis B Development

CONTEXT

After five decades of Hepatitis B Virus (HBV) vaccine discovery, HBV is still a major public health problem. Due to the high genetic diversity of HBV and selective pressure of the host immune system, intra-host evolution of this virus in different clinical manifestations is a hot topic of research. HBV infection causes a range of clinical manifestations from acute to chronic infection, cirrhosis and hepatocellular carcinoma. Among all forms of HBV infection manifestations, fulminant hepatitis B infection possesses the highest fatality rate. Almost 1% of the acutely infected patients develop fulminant hepatitis B, in which the mortality rate is around 70%.

EVIDENCE ACQUISITION

All published papers deposited in Genbank, on the topic of fulminant hepatitis were reviewed and their virological aspects were investigated. In this review, we highlight the genomic diversity of HBV reported from patients with fulminant HBV infection.

RESULTS

The most commonly detected diversities affect regulatory motifs of HBV in the core and S region, indicating that these alterations may convert the virus to an aggressive strain. Moreover, mutations at T-cell and B-cell epitopes located in pre-S1 and pre-S2 proteins may lead to an immune evasion of the virus, likely favoring a more severe clinical course of infection. Furthermore, point and frame shift mutations in the core region increase the viral replication of HBV and help virus to evade from immune system and guarantee its persistence.

CONCLUSIONS

Fulminant hepatitis B is associated with distinct mutational patterns of HBV, underlining that genomic diversity of the virus is an important factor determining its pathogenicity.

Chronic HDV/HBV co-infection: predictors of disease stage---a case series of HDV-3 patients

BACKGROUND & AIMS

Chronic HDV/HBV co-infection is perhaps the most intriguing amongst all viral hepatitis. Only few studies focus deeply on this topic, particularly with patients infected with HDV-3. This study aimed to identify predictors of advanced disease, examining a cross-sectional data of 64 patients.

METHODS

Histological grading was used to characterize the disease stages and viral loads were tested as predictors of necroinflammatory activity and fibrosis.

RESULTS

We identified three HDV/HBV co-infection patterns: patients with predominant HDV replication (56.3%), patients with similar viral loads of both viruses (40.6%), and patients with predominant HBV replication (3.1%). Mean HDV-RNA showed a positive trend regarding inflammatory activity and grade of fibrosis. HDV viral load correlated positively with serum levels of liver enzymes and inversely with platelets count. HBV viral load showed no correlation with any of the above parameters. Advanced fibrosis was associated with age, splenomegaly, and HDV viral load of more than 2 log10. Multiple logistic regression confirmed the independent effect of HDV viral predominance. Advanced necroinflammatory activity was independently associated with HDV viral load and splenomegaly.

CONCLUSIONS

HDV may possibly play an important and direct role in the establishment of necroinflammatory activity and fibrosis. Data show an indigenous HDV genotype, HDV-3, similar to those described in the Amazon region.

HBV/HDV co-infection in the Western Brazilian Amazonia: an intriguing mutation among HDV genotype 3 carriers

HDV infection still remains a serious public health problem in Amazonia. There are few data regarding the biomolecular aspects of HBV/HDV co-infection in this region. We studied 92 patients HBsAg(+) /anti-HDV IgG(+) followed at the Hepatitis Referral Centers of Porto Velho (RO), Rio Branco and Cruzeiro do Sul (AC), Brazil, from March 2006 to March 2007 for whom the HDV and/or the HBV genotype could be determined. The HDV genotype could be determined in 90 patients, while the HBV genotypes could be positively determined in 74. HBV subgenotype F2 is the most prevalent (40.2%), followed by the subgenotypes A1 (15.2%) and D3 (8.7%), while 16.4% were other subgenotypes or genotypes, 4.3% were discordant and 15.2% were unamplifiable. Surprisingly, HDV genotype 3 (HDV-3) was found in all of the HBV/HDV-infected patients that could be genotyped for HDV, confirming that HDV-3 can associate with non-F HBV genotypes. However, a HDV-3 mutant was found in 29.3% of patients and was more frequently associated with non-F HBV genotypes (P < 0.001) than were nonmutant strains, suggesting that the mutation may facilitate association of HDV-3 with non-F HBV genotypes.

Hepatitis B virus subgenotype A1: evolutionary relationships between Brazilian, African and Asian isolates

Brazil is a country of low hepatitis B virus (HBV) endemicity in which the genotype A of HBV (HBV/A) is the most prevalent. The complete nucleotide sequences of 26 HBV/A isolates, originating from eight Brazilian states, were determined. All were adw2. Twenty-three belonged to subgenotype A1 and three to A2. By phylogenetic analysis, it was shown that all the 23 HBV/A1 isolates clustered together with isolates from Bangladesh, India, Japan, Nepal, the Philippines and United Arab Emirates, but not with those of Congo, Kenya, Malawi, Rwanda, South Africa, Tanzania, Uganda and Zimbabwe. Four amino acid residues in the polymerase (His138 in the terminal protein domain, Pro18 and His90 in the spacer, and Ser109 in the reverse transcriptase), and one (Phe17) in the precore region, predominated in Latin American and Asian HBV/A1 isolates, but were rarely encountered in African isolates, with the exception of those from Somalia. Specific variations of two adjacent amino acids in the C-terminal domain of the HBx protein, namely Ala146 and Pro147, were found in all the Brazilian, but rarely in the other HBV/A1 isolates. By Bayesian analysis, the existence of an 'Asian-American' clade within subgenotype A1 was supported by a posterior probability value of 0.996. The close relatedness of the Brazilian, Asian and Somalian isolates suggests that the HBV/A1 strains predominant in Brazil did not originate from the five million slaves who were imported from Central and Western Africa from 1551 to 1840, but rather from the 300-400,000 captives forcibly removed from southeast Africa at the middle of the 19th century.

Molecular epidemiology of hepatitis B and hepatitis delta viruses circulating in the Western Amazon region, North Brazil

Background

Hepatitis B virus (HBV) and hepatitis D virus (HDV) represent important public health problems in the Western Amazon region with reported cases of fulminant hepatitis. This cross sectional study describes HBV and HDV genotypes circulating in the Brazilian Amazon region.

Methods

HBsAg positive individuals (n = 224) were recruited in Manaus/Amazonas State (130 blood donors from the Hematology and Hemotherapy Foundation from Amazonas/HEMOAM; 60 subjects from outpatient clinic) and in Eirunepe city (n = 34) from 2003–2009. Most participants (n = 153) lived in Manaus, 63 were from 20 remote isolated municipalities, 8 lived outside Amazonas State. Genotyping was based on PCR products: HBV genotype A-F specific primers, restricted length polymorphism for HDV. HDV isolates were directly sequenced (delta antigen 405 nucleotide fragment) and phylogenetic analysis performed (MEGA; neighbor-joining, Kimura’s two parameter).

Results

Most participants were young adult males and HBV mono-infection predominated (70.5%, 158/224). Among blood donors, outpatient subjects and individuals from Eirunepe, HBV/A prevailed followed by HBV/D and F (p > 0.05). HBV/A was more frequent in blood donors (p < 0.05). HBV-HDV coinfection rate was 8.5% in blood donors (11/130), 65.0% (39/60) in outpatient subjects and 47.0% (16/34) in individuals from Eirunepe. Compared to blood donors, coinfection was higher in outpatient subjects (65.0% versus 8.5%; RR = 5.0; CI 3.4-7.9; p < 0.0001) and in subjects from Eirunepe (47.0% versus 8.5%; RR = 5.5; CI 3.0-9.9; p < 0.0001). HBV-HDV coinfection rates were higher in patients from highly endemic remote cities. Only HDV genotype 3 was detected, HBV/F-HDV/3 predominated (20/38; 52.7%), followed by HBV/A-HDV/3 (31.6%; 12/38) and HBV/D-HDV/3 (15.8%; 6/38).

Conclusions

The description of HBV and HDV genotypes circulating in the western Amazon can contribute to a better understanding of their relevance on the regional epidemics. These infections are highly endemic in the Amazon where their control is challenged by its vast territorial dimension with small, hard-to-reach municipalities dispersed into the jungle and populated by diverse ethnic groups.

High prevalence and significance of hepatitis D virus infection among treatment-naïve HBsAg-positive patients in Northern Vietnam

Background

Hepatitis D virus (HDV) infection is considered to cause more severe hepatitis than hepatitis B virus (HBV) monoinfection. With more than 9.5 million HBV-infected people, Vietnam will face an enormous health burden. The prevalence of HDV in Vietnamese HBsAg-positive patients is speculative. Therefore, we assessed the prevalence of HDV in Vietnamese patients, determined the HDV-genotype distribution and compared the findings with the clinical outcome.

Methods

266 sera of well-characterized HBsAg-positive patients in Northern Vietnam were analysed for the presence of HDV using newly developed HDV-specific RT-PCRs. Sequencing and phylogenetic analysis were performed for HDV-genotyping.

Results

The HDV-genome prevalence observed in the Vietnamese HBsAg-positive patients was high with 15.4% while patients with acute hepatitis showed 43.3%. Phylogenetic analysis demonstrated a predominance of HDV-genotype 1 clustering in an Asian clade while HDV-genotype 2 could be also detected. The serum aminotransferase levels (AST, ALT) as well as total and direct bilirubin were significantly elevated in HDV-positive individuals (p<0.05). HDV loads were mainly low (<300 to 4.108 HDV-copies/ml). Of note, higher HDV loads were mainly found in HBV-genotype mix samples in contrast to single HBV-infections. In HBV/HDV-coinfections, HBV loads were significantly higher in HBV-genotype C in comparison to HBV-genotype A samples (p<0.05).

Conclusion

HDV prevalence is high in Vietnamese individuals, especially in patients with acute hepatitis B. HDV replication activity showed a HBV-genotype dependency and could be associated with elevated liver parameters. Besides serological assays molecular tests are recommended for diagnosis of HDV. Finally, the high prevalence of HBV and HDV prompts the urgent need for HBV-vaccination coverage.