Hepatitis Delta Research Articles

A holistic evaluation of patients with chronic Hepatitis D virus (HDV) infection enrolled in the Italian PITER-B and delta cohort

Background and AimsWe aimed to characterize the epidemiologic and comorbidities profiles of patients with chronic Hepatitis D (CHD) followed in clinical practice in Italy and explored their interferon (IFN) eligibility. MethodsThis was a cross-sectional study of the PITER cohort consisting of consecutive HBsAg-positive patients from 59 centers over the period 2019-2023. Multivariable analysis was performed by logistic regression model. ResultsOf 5492 HBsAg-positive enrolled patients, 4152 (75.6%) were screened for HDV, 422 (10.2%) were anti-HDV positive. Compared with HBsAg mono-infected, anti-HDV positive patients were more often younger, non-Italians, with a history of drug use, had elevated alanine transaminase (ALT), cirrhosis, or hepatocellular carcinoma (HCC). Compared with Italians, anti-HDV positive non-Italians were younger (42.2% age ≤ 40 years vs. 2.1%; P < 0.001), more often females (males 43.0% vs. 68.6%; P < 0.001) with less frequent cirrhosis and HCC. HDV-RNA was detected in 63.2% of anti-HDV-positive patients, who were more likely to have elevated ALT, cirrhosis, and HCC. Extrahepatic comorbidities were present in 47.4% of anti-HDV positive patients and could affect the eligibility of IFN-containing therapies in at least 53.0% of patients in care. ConclusionsCHD affects young, foreign-born patients and older Italians, of whom two-thirds had cirrhosis or HCC. Comorbidities were frequent in both Italians and non-Italians and impacted eligibility for IFN.

Exosomes as Conduits: Facilitating Hepatitis B Virus-Independent Hepatitis D Virus Transmission and Propagation in Hepatocytes.

A number of research studies, including ours, have spotlighted exosomes as critical facilitators of viral dissemination. While hepatitis B virus (HBV) transmission through exosomes has been studied, the focus on its satellite virus, the hepatitis delta virus (HDV), has been unexplored in this context. HDV, although being a defective virus, can replicate its genome autonomously within hepatocytes, independently of HBV. Investigations on Huh7 cells revealed an intriguing phenomenon: the HDV proteins, S-HDAg and L-HDAg, are transmitted between cells without a complete viral structure. Detailed analysis further revealed that the expression of these proteins not only bolstered exosome secretion but also ensured their enrichment within these vesicles. Our experimental approach utilized transfection of various plasmids to examine the role of HDV RNA and proteins in the process. One salient finding was the differential propagation of the HDV proteins S-HDAg and L-HDAg, suggesting intricate molecular mechanisms behind their transmission. Notably, the purity of our exosome preparations was monitored using markers such as TSG101 and CD81. Importantly, these exosomes were found to carry both HDV RNA and proteins, highlighting their role in HDV dissemination. This novel study underscores the role of exosomes in mediating the transmission of HDV components between hepatocytes independent of HBV. These revelations about the exosomal pathway of HDV transmission provide a foundation for the development of innovative therapeutic strategies against HDV infections.

Investigating the Genetic Diversity of Hepatitis Delta Virus in Hepatocellular Carcinoma (HCC): Impact on Viral Evolution and Oncogenesis in HCC.

Hepatitis delta virus (HDV), an RNA virus with two forms of the delta antigen (HDAg), relies on hepatitis B virus (HBV) for envelope proteins essential for hepatocyte entry. Hepatocellular carcinoma (HCC) ranks third in global cancer deaths, yet HDV's involvement remains uncertain. Among 300 HBV-associated HCC serum samples from Taiwan's National Health Research Institutes, 2.7% (8/300) tested anti-HDV positive, with 62.7% (5/8) of these also HDV RNA positive. Genotyping revealed HDV-2 in one sample, HDV-4 in two, and two samples showed mixed HDV-2/HDV-4 infection with RNA recombination. A mixed-genotype infection revealed novel mutations at the polyadenylation signal, coinciding with the ochre termination codon for the L-HDAg. To delve deeper into the possible oncogenic properties of HDV-2, the predominant genotype in Taiwan, which was previously thought to be less associated with severe disease outcomes, an HDV-2 cDNA clone was isolated from HCC for study. It demonstrated a replication level reaching up to 74% of that observed for a widely used HDV-1 strain in transfected cultured cells. Surprisingly, both forms of HDV-2 HDAg promoted cell migration and invasion, affecting the rearrangement of actin cytoskeleton and the expression of epithelial-mesenchymal transition markers. In summary, this study underscores the prevalence of HDV-2, HDV-4, and their mixed infections in HCC, highlighting the genetic diversity in HCC as well as the potential role of both forms of the HDAg in HCC oncogenesis.

Prevalence, clinical and virological characteristics and short-term prognosis of hepatitis delta infection among patients with HIV/HBV in Nouakchott, Mauritania.

Patients living with HIV infection (PLWH) are at risk of acquiring HBV and HDV. The present study aimed to determine the prevalence and characteristics of HIV-HDV-HBV tri-infection in comparison with HIV-HBV coinfection and to estimate severities and outcomes of associated liver diseases in Mauritanian PLWH. Two-hundred-ninety-two consecutive HBsAg-positive PLWH were included (mean age: 37 years). Clinical data were recorded. Anti-HDV antibodies, HBV and HDV viral loads (VLs) and genotype were determined. APRI, FIB-4 and FibroScan were performed to evaluate the severity of liver disease. The anti-HDV antibodies prevalence was 37% and HDV RNA was positive in 40.7% of patients. Genetic diversities were found with HDV genotype 1 (93%) and HBV genotypes D (42.5%) and E (38%). The HBV VL was detectable in 108 patients at inclusion, and mutations associated with HBV resistance were found in 20. For almost all variables studied, including FIB-4 and APRI scores, no significant differences were found between anti-HDV-Ab positive or negative patients. FibroScan examination, which was performed in 110 patients at end-of-follow-up showed higher, but NS values, in HDV positive patients. After a mean follow-up of 24.55 ± 8.01 months (n = 217 patients), a highly significant worsening of APRI and FIB-4 scores was found. Moreover, patients with HDV showed more severe liver disease progression despite an efficient therapy. In a substantial Mauritanian cohort of relatively young PLWH, we found high HDV prevalence and worsening liver disease. In high-risk countries, screening for HDV and providing appropriate follow-up and treatments are warranted in PLWH.

Highlights from the 2023 International Meeting on the Molecular Biology of Hepatitis B virus.

Since its discovery in 1965, our understanding of the hepatitis B virus (HBV) replication cycle and host immune responses has increased markedly. In contrast, our knowledge of the molecular biology of hepatitis delta virus (HDV), which is associated with more severe liver disease, is less well understood. Despite the progress made, critical gaps remain in our knowledge of HBV and HDV replication and the mechanisms underlying viral persistence and evasion of host immunity. The International HBV Meeting is the leading annual scientific meeting for presenting the latest advances in HBV and HDV molecular virology, immunology, and epidemiology. In 2023, the annual scientific meeting was held in Kobe, Japan and this review summarises some of the advances presented at the Meeting and lists gaps in our knowledge that may facilitate the development of new therapies.

Protective role of RIPK1 scaffolding against HDV-induced hepatocyte cell death and the significance of cytokines in mice.

Hepatitis delta virus (HDV) infection represents the most severe form of human viral hepatitis; however, the mechanisms underlying its pathology remain incompletely understood. We recently developed an HDV mouse model by injecting adeno-associated viral vectors (AAV) containing replication-competent HBV and HDV genomes. This model replicates many features of human infection, including liver injury. Notably, the extent of liver damage can be diminished with anti-TNF-α treatment. Here, we found that TNF-α is mainly produced by macrophages. Downstream of the TNF-α receptor (TNFR), the receptor-interacting serine/threonine-protein kinase 1 (RIPK1) serves as a cell fate regulator, playing roles in both cell survival and death pathways. In this study, we explored the function of RIPK1 and other host factors in HDV-induced cell death. We determined that the scaffolding function of RIPK1, and not its kinase activity, offers partial protection against HDV-induced apoptosis. A reduction in RIPK1 expression in hepatocytes through CRISPR-Cas9-mediated gene editing significantly intensifies HDV-induced damage. Contrary to our expectations, the protective effect of RIPK1 was not linked to TNF-α or macrophage activation, as their absence did not alter the extent of damage. Intriguingly, in the absence of RIPK1, macrophages confer a protective role. However, in animals unresponsive to type-I IFNs, RIPK1 downregulation did not exacerbate the damage, suggesting RIPK1's role in shielding hepatocytes from type-I IFN-induced cell death. Interestingly, while the damage extent is similar between IFNα/βR KO and wild type mice in terms of transaminase elevation, their cell death mechanisms differ. In conclusion, our findings reveal that HDV-induced type-I IFN production is central to inducing hepatocyte death, and RIPK1's scaffolding function offers protective benefits. Thus, type-I IFN together with TNF-α, contribute to HDV-induced liver damage. These insights may guide the development of novel therapeutic strategies to mitigate HDV-induced liver damage and halt disease progression.

Hepatocyte Intrinsic Innate Antiviral Immunity against Hepatitis Delta Virus Infection: The Voices of Bona Fide Human Hepatocytes.

The pathogenesis of viral infection is attributed to two folds: intrinsic cell death pathway activation due to the viral cytopathic effect, and immune-mediated extrinsic cellular injuries. The immune system, encompassing both innate and adaptive immunity, therefore acts as a double-edged sword in viral infection. Insufficient potency permits pathogens to establish lifelong persistent infection and its consequences, while excessive activation leads to organ damage beyond its mission to control viral pathogens. The innate immune response serves as the front line of defense against viral infection, which is triggered through the recognition of viral products, referred to as pathogen-associated molecular patterns (PAMPs), by host cell pattern recognition receptors (PRRs). The PRRs-PAMPs interaction results in the induction of interferon-stimulated genes (ISGs) in infected cells, as well as the secretion of interferons (IFNs), to establish a tissue-wide antiviral state in an autocrine and paracrine manner. Cumulative evidence suggests significant variability in the expression patterns of PRRs, the induction potency of ISGs and IFNs, and the IFN response across different cell types and species. Hence, in our understanding of viral hepatitis pathogenesis, insights gained through hepatoma cell lines or murine-based experimental systems are uncertain in precisely recapitulating the innate antiviral response of genuine human hepatocytes. Accordingly, this review article aims to extract and summarize evidence made possible with bona fide human hepatocytes-based study tools, along with their clinical relevance and implications, as well as to identify the remaining gaps in knowledge for future investigations.

Development of a dual channel detection system for pan-genotypic simultaneous quantification of hepatitis B and delta viruses

Hepatitis B virus (HBV) infection remains a major public health problem and, in associated co-infection with hepatitis delta virus (HDV), causes the most severe viral hepatitis and accelerated liver disease progression. As a defective satellite RNA virus, HDV can only propagate in the presence of HBV infection, which makes HBV DNA and HDV RNA the standard biomarkers for monitoring the virological response upon antiviral therapy, in co-infected patients. Although assays have been described to quantify these viral nucleic acids in circulation independently, a method for monitoring both viruses simultaneously is not available, thus hampering characterization of their complex dynamic interactions. Here, we describe the development of a dual fluorescence channel detection system for pan-genotypic, simultaneous quantification of HBV DNA and HDV RNA through a one-step quantitative PCR. The sensitivity for both HBV and HDV is about 10 copies per microliter without significant interference between these two detection targets. This assay provides reliable detection for HBV and HDV basic research in vitro and in human liver chimeric mice. Preclinical validation of this system on serum samples from patient on or off antiviral therapy also illustrates a promising application that is rapid and cost-effective in monitoring HBV and HDV viral loads simultaneously.

Bulevirtide monotherapy in patients with chronic HDV: Efficacy and safety results through week 96 from a phase III randomized trial

Bulevirtide (BLV), a first-in-class entry inhibitor, is approved in Europe for the treatment of chronic hepatitis delta (CHD). BLV monotherapy was superior to delayed treatment at week (W) 48, the primary efficacy endpoint, in the MYR301 study (NCT03852719). Here, we assessed if continued BLV therapy until W96 would improve virologic and biochemical response rates, particularly among patients who did not achieve virologic response at W24. In this ongoing, open-label, randomized phase III study, patients with CHD (N= 150) were randomized (1:1:1) to treatment with BLV 2mg/day (n= 49) or 10mg/day (n= 50), each for 144 weeks, or to delayed treatment for 48 weeks followed by BLV 10mg/day for 96 weeks (n= 51). Combined response was defined as undetectable hepatitis delta virus (HDV) RNA or a decrease in HDV RNA by ≥2 log10 IU/ml from baseline and alanine aminotransferase (ALT) normalization. Other endpoints included virologic response, ALT normalization, and change in HDV RNA. Of 150 patients, 143 (95%) completed 96 weeks of the study. Efficacy responses were maintained and/or improved between W48 and W96, with similar combined, virologic, and biochemical response rates between BLV 2 and 10mg. Of the patients with a suboptimal early virologic response at W24, 43% of non-responders and 82% of partial responders achieved virologic response at W96. Biochemical improvement often occurred independently of virologic response. Adverse events were mostly mild, with no serious adverse events related to BLV. Virologic and biochemical responses were maintained and/or increased with longer term BLV therapy, including in those with suboptimal early virologic response. BLV monotherapy for CHD was safe and well tolerated through W96. In July 2023, bulevirtide was fully approved for the treatment of chronic hepatitis delta (CHD) in Europe based on clinical study results from up to 48 weeks of treatment. Understanding the efficacy and safety of bulevirtide over the longer term is important for healthcare providers. In this analysis, we demonstrate that bulevirtide monotherapy for 96 weeks in patients with CHD was associated with continued improvements in combined, virologic, and biochemical responses as well as liver stiffness from week 48at both the 2mg and 10mg doses. Patients with suboptimal virologic responses to bulevirtide at week 24 also benefited from continued therapy, with the majority achieving virologic response or biochemical improvement by week96. NCT03852719.

Clinical profile and parameters of patients monoinfected with HBV and infected with HDV in Western Amazon

BackgroundHepatitis Delta represents a greater risk in the progression of advanced liver disease and HCC compared with HBV. The exact mechanism that determines the spontaneous clearance of delta virus or its progression to cirrhosis remains unknown. Therefore, this study aimed to analyze the clinical profile of HBV and HBV/HDV individuals in the Western Amazon. MethodsThe study was carried out at the Specialized Outpatient Clinic for Viral Hepatitis belonging to the Centro de Pesquisa em Medicina Tropical de Rondônia/CEPEM. 100 individuals were included, stratified into two groups: 50 with hepatitis B virus and 50 with hepatitis Delta virus. ResultsThe overall mean age was 48 years. For the HBV and HDV groups, 66 % (33/50) and 54 % (27/50) were men and 56 % (28/50) and 58 % (29/50) were on antiviral treatment, respectively. Patients with detectable HDV-RNA demonstrated high levels of ALT and AST compared to individuals with undetectable HDV-RNA. Comparative analysis between HBV carriers and infected with HDV shows significant differences in terms of age, HBV-DNA levels, albumin, hepatomegaly and splenomegaly. ConclusionSeveral markers were important for differentiating HBV and HDV infections. HDV-RNA detectable showed significant changes in biomarkers compared to undetectable patients, suggesting a possible worse prognostic effect in this group.

Hepatitis delta testing trends in a US national cohort: An analysis of patient and provider-level predictive factors.

The low prevalence of HDV infection in the United States could be attributed to insufficient testing rate, which can result in an underestimation of the true burden of HDV. The primary objective of this study is to quantify the prevalence of and factors associated with HDV antibody (anti-HDV) or RNA testing, among participants with positive HBsAg in the Veterans Health Administration (VHA). We conducted a retrospective cohort study of participants who tested positive for HBsAg between January 2000 and December 2022 within the VHA. We identified those who were tested for HDV, and patient and provider-level factors associated with HDV testing. Of 41,658 participants with positive HBsAg who had follow-up, 4438 (10.7%) were tested at least once for HDV, of which 135 (3.0%) were positive. Participants in the Northeast (adjusted odds ratio [aOR]: 1.30, 95% CI: 1.17-1.44, p<0.001), and receiving hepatology care (aOR: 1.38, 95% CI: 1.24-1.54, p<0.001) were more likely, while those in the Midwest (aOR: 0.69, 95% CI: 0.60-0.79, p<0.001), under the care of a primary care provider (aOR: 0.61, 95% CI: 0.50-0.74, p<0.001), Blacks (aOR: 0.85, 95% CI: 0.77-0.94, p=0.001), participants who were HCV antibody-positive (aOR: 0.89, 95% CI: 0.81-0.99, p=0.03), and participants who were HIV-positive (aOR: 0.80, 95% CI: 0.71-0.90, p<0.001) were less likely to be tested for HDV. HDV screening rates in the VHA remain low overall. Participants who are Black, living in the Midwest, patients who are HIV-positive, and patients who are HCV-positive are less likely to be tested for HDV. These results suggest that risk-based screening strategies are ineffective in the VHA and highlight the need for refining testing strategies to increase HDV screening rates.

Prevalence, characteristics, and virologic correlations of hepatitis delta (D) among patients with hepatitis B surface antigen in Mongolia.

Clinical and biochemical features of hepatitis delta virus (HDV) infections in Mongolia remain largely unknown. We aimed to investigate the clinical characteristics of HDV patients in Mongolia using several markers. The 143 hepatitis B surface antigen (HBsAg)-positive patients were divided into 122 HDV-positive and 21 HDV-negative patients by HDV RNA positivity. Subgroup analysis was performed between hepatitis B e antigen (HBeAg)-positive and -negative HDV-positive patients. Liver function, quantitative HBsAg (qHBsAg), anti-HDV Immunoglobulin (Ig) M, Mac-2 binding protein glycosylation isomer (M2BPGi), hepatitis B virus (HBV) DNA level, and HDV RNA level were tested. HDV RNA was positive in 85.3% (122/143) of patients showing anti-HDV IgG. Liver disease activity was higher in HDV-positive patients than in HDV-negative patients. The HDV-positive group included a higher proportion of patients with high qHBsAg and M2BPGi levels (p < 0.001). The positivity rate for anti-HDV IgM was significantly higher in the HDV-positive group (p < 0.001). HDV RNA levels showed an inverse correlation with qHBsAg levels in HBeAg-positive-HDV-positive patients (r = -0.49, p = 0.034), and a positive correlation with qHBsAg levels in HBeAg-negative patients (r = 0.35, p < 0.001). Hepatitis B virus (HBV) DNA and HDV RNA levels did not show any correlation. M2BPGi levels likewise did not correlate with HDV RNA levels. A high positivity rate for HDV RNA was observed for HBV patients in Mongolia using the highly sensitive HDV RNA assay. The positivity rate for anti-HDV IgM was high in HDV RNA-positive patients. Severity of liver disease and M2BPGi levels were both high in the HDV RNA-positive group.

Cell Culture Models for Hepatitis B and D Viruses Infection: Old Challenges, New Developments and Future Strategies.

Chronic Hepatitis B and D Virus (HBV and HDV) co-infection is responsible for the most severe form of viral Hepatitis, the Hepatitis Delta. Despite an efficient vaccine against HBV, the HBV/HDV infection remains a global health burden. Notably, no efficient curative treatment exists against any of these viruses. While physiologically distinct, HBV and HDV life cycles are closely linked. HDV is a deficient virus that relies on HBV to fulfil is viral cycle. As a result, the cellular response to HDV also influences HBV replication. In vitro studying of HBV and HDV infection and co-infection rely on various cell culture models that differ greatly in terms of biological relevance and amenability to classical virology experiments. Here, we review the various cell culture models available to scientists to decipher HBV and HDV virology and host-pathogen interactions. We discuss their relevance and how they may help address the remaining questions, with one objective in mind: the development of new therapeutic approaches allowing viral clearance in patients.

Prospective study of hepatitis B and D epidemiology and risk factors in Romania: A 10-year update.

The global burden of hepatitis D virus (HDV) infection represents a major medical challenge and a public health crisis worldwide. However, there is a lack of accurate data on the epidemiology and risk factors for HDV. Hepatitis B virus (HBV) and HDV coinfection causes the most severe form of viral hepatitis, leading to a higher cumulative incidence of liver-related events compared with HBV monoinfection, including the need for liver transplantation and death. To investigate the epidemiology, natural history, risk factors and clinical management of HBV and HDV coinfection in Romanian patients. This prospective study was conducted between January and July 2022 in six tertiary gastroenterology and hepatology referral centres in Romania. All consecutive adults admitted for any gastroenterology diagnosis who were HBV-positive were enrolled. Patients with acute hepatitis or incomplete data were excluded. Of the 25390 individuals who presented with any type of gastroenterology diagnosis during the study period, 963 met the inclusion criteria. Testing for anti-HDV antibodies and HDV RNA was performed for all participants. Demographic and risk factor data were collected by investigators using medical charts and patient questionnaires. All data were stored in an anonymized online database during the study. The prevalence of HBV was 3.8%; among these patients, the prevalence of HBV/HDV coinfection was 33.1%. The median age of the study population was 54.0 years, and it consisted of 55.1% men. A higher prevalence of HBV/HDV coinfection was observed in patients 50-69 years old. Patients with HBV/HDV coinfection were significantly older than those with HBV monoinfection (P = 0.03). Multivariate multiple regression analysis identified female gender (P = 0.0006), imprisonment (P < 0.0001), older age at diagnosis (P = 0.01) and sexual contact with persons with known viral hepatitis (P = 0.0003) as significant risk factors for HDV. This study shows that HDV infection among those with HBV remains endemic in Romania and updates our understanding of HDV epidemiology and associated risk factors. It emphasizes the need for systematic screening for HDV infection and collaborative initiatives for controlling and preventing HBV and HDV infection.

Hepatitis Delta Virus and Hepatocellular Carcinoma.

The hepatitis D virus (HDV) is a compact, enveloped, circular RNA virus that relies on hepatitis B virus (HBV) envelope proteins to initiate a primary infection in hepatocytes, assemble, and secrete new virions. Globally, HDV infection affects an estimated 12 million to 72 million people, carrying a significantly elevated risk of developing cirrhosis, liver failure, and hepatocellular carcinoma (HCC) compared to an HBV mono-infection. Furthermore, HDV-associated HCC often manifests at a younger age and exhibits more aggressive characteristics. The intricate mechanisms driving the synergistic carcinogenicity of the HDV and HBV are not fully elucidated but are believed to involve chronic inflammation, immune dysregulation, and the direct oncogenic effects of the HDV. Indeed, recent data highlight that the molecular profile of HCC associated with HDV is unique and distinct from that of HBV-induced HCC. However, the question of whether the HDV is an oncogenic virus remains unanswered. In this review, we comprehensively examined several crucial aspects of the HDV, encompassing its epidemiology, molecular biology, immunology, and the associated risks of liver disease progression and HCC development.

Hepatitis B Delta: assessment of the knowledge and practices of hepato-gastroenterologists practicing in non-academic settings in France.

Data on the management of Hepatitis B-Delta (HB-D) by hepatogastroenterologists (HGs) practicing in nonacademic hospitals or private practices are unknown in France. We aimed to evaluate the knowledge and practices of HGs practicing in nonacademic settings regarding HB-D. A Google form document was sent to those HGs from May to September 2021. A total of 130 HGs (mean age, 45 years) have participated in this survey. Among HBsAg-positive patients, Delta infection was sought in only 89% of cases. Liver fibrosis was assessed using FibroScan in 77% of the cases and by liver biopsy in 81% of the cases. A treatment was proposed for patients with >F2 liver fibrosis in 49% of the cases regardless of transaminase levels and for all the patients by 39% of HGs. Responding HGs proposed a treatment using pegylated interferon in 50% of cases, bulevirtide in 45% of cases and a combination of pegylated interferon and bulevirtide in 40.5% of cases. Among the criteria to evaluate the treatment efficacy, a decrease or a normalization of transaminases was retained by 89% of responding HGs, a reduction of liver fibrosis score for 70% of them, an undetectable delta RNA and HBsAg for 55% of them and a 2 log 10 decline in delta viremia for 62% of the cases. Hepatitis Delta screening was not systematically performed in HBsAg-positive patients despite the probable awareness and knowledge of the few responders who were able to prescribe treatments of hepatitis delta.

Dismantling Barriers to Hepatitis B and Delta Screening, Prevention, and Linkage to Care among the PWUD Community in Philadelphia.

The prevalence of hepatitis B and delta viruses (HBV/HDV) among people who use drugs (PWUD) remains largely unknown. In the context of one Philadelphia-based harm reduction organization (HRO), this study aimed to assess HBV/HDV prevalence and facilitate linkage to care. Participants completed a demographic HBV/HDV risk factor survey and were screened for HBV and reflexively for HDV if positive for HBV surface antigen or isolated core antibody. Fisher's exact tests and regression were used to understand relationships between risks and HBV blood markers. Of the 498 participants, 126 (25.3%) did not have hepatitis B immunity, 52.6% had been vaccinated against HBV, and 17.9% had recovered from a past infection. Eleven (2.2%) participants tested positive for isolated HBV core antibody, 10 (2.0%) for HBV surface antigen, and one (0.2%) for HDV antibody. History of incarceration was associated with current HBV infection, while transactional sex and experience of homelessness were predictive of previous exposure. This study found high rates of current and past HBV infection, and a 10% HBV/HDV co-infection rate. Despite availability of vaccine, one quarter of participants remained vulnerable to infection. Findings demonstrate the need to improve low-threshold HBV/HDV screening, vaccination, and linkage to care among PWUD. The study also identified gaps in the HBV/HDV care cascade, including lack of point-of-care diagnostics and lack of support for HROs to provide HBV services.

Higher correlation between neutralizing antibodies and surrogate neutralizing or binding antibodies in COVID-19 patients than vaccine recipients.

This study determined the seropositive rates and levels of antibodies to severe acute respiratory syndrome coronavirus-2 in 50 patients and 108 vaccinees using microneutralization test (MNT), surrogate virus neutralization test (sVNT), chemiluminescent microparticle immunoassay (CMIA), and electrochemiluminescence immunoassay (ECLIA). MNT, as the reference method, employed living clade S and Delta viruses to measure neutralizing (NT) antibodies, while sVNT employed wild type strain and Delta receptor-binding domains (RBD) as the test antigens to measure sVNT antibodies. CMIA and ECLIA employed only one version of RBD to measure the binding antibodies. Our study performed S gene sequencing of the test virus to exclude undesired mutants that might lead to changes in antibody levels in MNT assay. We showed that spike protein amino acid sequences of our Delta virus contained 13 amino acid changes, with 3 related to the reduced neutralization. The MNT assay showed a significant reduction in seropositive rates and antibody levels in the patients' sera when the Delta variant replaced clade S as the test virus. In contrast, the seropositive rates determined by sVNT assay using wild type strain RBD and Delta RBD were non-significantly different, suggesting that sVNT assay could not identify the difference between the antigenicity of wild type RBD and Delta RBD. Furthermore, the correlation between the levels of NT and sVNT antibodies was moderate with the patients' sera but modest with the post-vaccination sera. The seropositive rates in the patients, as determined by CMIA or ECLIA, were not different from the MNT assay using clade S, but not Delta, as the test virus. In all analyses, the correlations between the antibody levels measured by MNT and the other 3 assays were modest to moderate, with the r-values of 0.3500-0.7882.

An updated assessment of hepatitis delta prevalence among adults in Canada: A meta-analysis.

Foreign-born (FB) persons represent a large proportion of adults with chronic hepatitis B (CHB) in Canada due to higher prevalence rates in countries of birth for FB persons. Suboptimal awareness and low rates of hepatitis delta virus (HDV) testing contribute to underdiagnosis and gaps in accurate estimates of Canada HDV prevalence. We aim to provide an assessment of CHB and HDV prevalence in Canada using a comprehensive literature review and meta-analysis. A comprehensive literature review of articles reporting HBsAg seroprevalence and anti-HDV prevalence was conducted to calculate country-specific rates and pooled prevalence of CHB and HDV using meta-analyses. Country-specific CHB and HDV rate estimates were combined with number of FB persons in Canada in 2021 from Statistics Canada to estimate total numbers of FB with CHB and HDV, respectively. These estimates were combined with estimates of Canada-born persons with CHB and HDV to yield the total number of persons with CHB and HDV. In 2021, we estimated 0.550 million (M) (95% CI 0.488-0.615) persons with CHB; 0.344 M (95% CI 0.288-0.401) were FB and 0.206 M (95% CI: 0.200-0.214) were Canada-born. The weighted average HDV prevalence among FB persons in Canada was 5.19% (17,848 [95% CI 9611-26,052] persons), among whom 50% emigrated from Asia and 31% from Africa. When combined with estimates of Canada-born persons with HDV, we estimate 35,059 (95% CI: 18,744-52,083) persons with HDV in Canada. In conclusion, we estimate 0.550 M and 35,059 persons living with CHB and HDV, respectively, in Canada in 2021.

Multiple Barriers Impede Screening for Hepatitis Delta: An Internet-Based Survey of Healthcare Providers.

Hepatitis delta virus (HDV) increases risk of cirrhosis and hepatocellular carcinoma in patients with hepatitis B; however, HDV screening rates are low. We assessed providers' perceived barriers to HDV screening and management. We distributed an Internet-based survey to members of 3 gastroenterology/hepatology organizations. Most respondents, 69.3%, correctly identified the appropriate HDV screening test. Several reported barriers to HDV care, including uncertainty of screening criteria, 55.5%, and lack of treatment knowledge, 66.7%. Our findings highlight the need for increased education regarding HDV care. Education should be combined with standardized approaches that increase ease of HDV screening.