Search Results (52)

Hepatitis delta virus (HDV) infection is associated with severe hepatic complications and rapid progression towards liver cirrhosis and hepatocellular carcinoma. Accurate measurement of HDV RNA is critical for monitoring therapeutic responses, especially during treatment with novel therapies such as bulevirtide (BLV). This study compared the analytical performance of two HDV RNA quantification assays, Bosphore (Anatolia) and AltoStar^® (Altona), focusing on their sensitivity, specificity, and potential implications for clinical management. Sixty-one clinical samples from twenty-four patients, including fifteen HDV-infected patients receiving BLV treatment and nine controls, were tested using each assay. Of 30 samples identified as HDV-negative by the Bosphore assay, 17 (56.7%) were HDV-positive with AltoStar^®, demonstrating the superior sensitivity (p < 0.0001) of the latter assay. Quantitative analyses revealed consistently higher viral load measurements with AltoStar^® compared to Bosphore, with a difference of 1.23 Log IU/mL and a moderate correlation (r² = 0.7385) between assays. Each assay demonstrated a high specificity, with no false positives detected among control samples. However, our findings suggest that differences in assay sensitivity could impact the evaluation of virological response, highlighting the risk of false-negative results in chronically HDV-infected patients with low-level viremia. This emphasizes the need for careful assay selection to accurately monitor treatment outcomes. Full article

Hepatitis E virus (HEV) is a positive-sense, single-stranded RNA virus that poses a significant public health risk, yet its study is hindered by the complexity of conventional RNA-based reverse genetics systems. These systems require multiple steps, including genome cloning, in vitro transcription, and capping, making them labor-intensive and susceptible to RNA degradation. In this study, we developed a single-step, plasmid-based HEV expression system that enabled direct intracellular transcription of the full-length HEV genome under a cytomegalovirus immediate-early (CMV-IE) promoter. The viral genome was flanked by hammerhead (HH) and hepatitis delta virus (HDV) ribozymes to ensure precise self-cleavage and the generation of authentic 5′ and 3′ termini. This system successfully supported HEV genome replication, viral protein expression, and progeny virion production at levels comparable to those obtained using in vitro-transcribed, capped HEV RNA. Additionally, a genetic marker introduced into the plasmid construct was stably retained in progeny virions, demonstrating the feasibility of targeted genetic modifications. However, plasmid-derived HEV exhibited delayed replication kinetics, likely due to the absence of an immediate 5′ cap. Attempts to enhance capping efficiency through co-expression of the vaccinia virus capping enzyme failed to improve HEV replication, suggesting that alternative strategies, such as optimizing the promoter design for capping, may be required. This plasmid-based HEV reverse genetics system simplifies the study of HEV replication and pathogenesis and provides a versatile platform for the genetic engineering of the HEV genome. Full article

In 2022, scientific societies agreed on a document with recommendations for a comprehensive diagnosis of viral hepatitis (B, C, and D). The aim was to evaluate the situation in Spain regarding the comprehensive diagnosis of viral hepatitis in a single blood draw before it is recommended. A panel of experts prepared a structured survey directed at hospitals (public or private with teaching accreditation) with ≥200 beds (sent 20 October 2022, closed 1 December 2022). The response rate was 61% (79/129; 52 hospitals with >500 beds). Among the participating hospitals, all could perform tests for HBsAg, anti-HCV, and HIV serology; 94% could perform PCR testing for HCV, 63% could test for anti-HDV, and 28% could test for HDV-RNA (67% [53/79] outsourced this testing). Point-of-care (POC) testing availability was low (24%), with 84% of these tests being supervised by the reference microbiological laboratory and the results being registered in the patients’ medical history. Ninety percent of the centers carried out the diagnosis in a single step (99% HCV, 70% HBV, 48% HDV, and 44% HBV-HDV). In addition, 77% used some communication strategy when an active infection was encountered (100% HCV, 49% HBV, and 31% HDV). Only 20% had an automated system for scheduling a specialist physician appointment. Most hospitals had the means for a comprehensive diagnosis of viral hepatitis in a single sample, but <50% could test for HBV/HDV. Alerts for continuity of care were available for HCV, but not HBV or HDV. POC device implementation is important for decentralized testing. Full article

This study aimed to assess the prevalence of HDV (hepatitis delta virus), HCV (hepatitis C virus), and HIV (human immunodeficiency virus) coinfections among HBsAg-positive patients and to determine the severity of liver fibrosis and biochemical markers. Furthermore, the study sought to evaluate the noninvasive fibrosis scores (APRI and FIB4) in predicting the severity of liver disease in patients with hepatitis B. A retrospective analysis of 1434 patients with chronic HBV admitted between January 2020 and December 2024 was conducted at Sincan Tertiary Hospital. The positivity rates of the following antibodies were the focus of the study: anti-HDV, anti-HCV, and anti-HIV. In addition to these, the levels of HIV-RNA, HCV-RNA and HBV-DNA, as well as several biochemical markers (ALT, AST, INR, albumin, bilirubin and platelet count) were also evaluated. The APRI and FIB-4 scores were calculated. Of the 1434 patients, 49 (3.4%) tested positive for anti-HDV, 784 were screened for anti-HCV, and 749 were screened for anti-HIV. The positivity rates were 3.4% (27/784) and 3.4% (26/749), respectively. According to ROC analysis, the FIB-4 score had a statistically significant effect on predicting anti-HDV negativity (AUC = 0.59, p = 0.031). However, the APRI score was not a significant predictor for anti-HDV positivity (AUC = 0.53, p > 0.05). APRI and FIB-4 scores did not have a statistically significant discriminatory power in predicting anti-HCV and anti-HIV positivity (p > 0.05). The cut-off value for the FIB-4 score in predicting anti-HDV positivity was 1.72, with a sensitivity of 61.4% and a specificity of 42.9% (p = 0.031). Among the HCV/RNA-positive patients (n = 5), all were male, and two also had positive anti-HBe results with undetectable HBV/DNA levels. One HIV/RNA-positive patient, a foreign national, was confirmed to have HIV/HBV/HDV infection. All HBsAg-positive patients should undergo routine anti-HDV testing. Vaccination programmes are vital in preventing the spread of HDV. Dual screening strategies are essential for identifying infected individuals and developing prevention and treatment programmes. Anti-HDV positivity indicates advanced liver fibrosis, emphasising the importance of screening and monitoring. However, the limited accuracy of the APRI and FIB-4 scores for detecting coinfections highlights the need to integrate noninvasive methods with molecular diagnostics for precise management. Full article

Introduction: Hepatitis D virus (HDV) infection remains a significant global health challenge due to its severity and high risk of progression to cirrhosis and hepatocellular carcinoma (HCC). Bulevirtide, a novel HDV entry inhibitor, has shown promise in managing chronic hepatitis D by blocking viral entry into hepatocytes. This study evaluated the efficacy and safety of bulevirtide in reducing HDV RNA levels and improving liver function in a real-life cohort of Italian patients with HDV infection. Methods: This multicenter prospective trial enrolled 108 consecutive patients with chronic HDV infection, from June 2023 to June 2024, who received 2 mg/day of bulevirtide in combination with a nucleoside/nucleotide analogue for hepatitis B virus (HBV) infection. Patients with any stage of liver fibrosis or compensated cirrhosis were included. Data collected included demographic and clinical characteristics, liver function tests, HDV RNA levels, and adverse events at baseline and 6 months. Results: The virological response was achieved in 54.6% of patients (n = 59), with 36 demonstrating undetectable HDV RNA levels. Among responders, ALT levels decreased significantly from 67.0 U/mL [IQR 44.0–116.3] to 31.5 U/mL [IQR 24.0–36.5, p = 0.001], and AST levels from 66.0 U/mL [IQR 46.5–91.0] to 32.5 U/mL [IQR 28.0–38.0, p = 0.021]. Median HDV RNA dropped from 29,800 IU/mL [IQR 3100–375,000] to 0 IU/mL [IQR 0–291, p < 0.001]. No significant predictors of response emerged. Mild adverse events, including pruritus (5.6%) and injection-site reactions (1.9%) and flu-like syndrome (0.9) were reported, with no treatment discontinuation. Conclusions: Bulevirtide effectively reduces HDV RNA levels and improves liver function with a favorable safety profile, offering a promising therapeutic option for chronic hepatitis D. Further large-scale studies are needed to confirm these findings and explore long-term outcomes. Full article

Background: Hepatitis delta virus (HDV) infection represents the most severe form of viral hepatitis and is a significant global health challenge. Bulevirtide (BLV) is a novel therapeutic treatment that has resulted in variable response rates in HBV/HDV-coinfected patients. We evaluated clinical, virological, and polymorphic factors for the purpose of predicting BLV treatment success. Methods: Thirty HBV/HDV-coinfected patients received BLV monotherapy (2 mg/day) for 24 to 48 weeks. Baseline (BL) serum samples were collected to assess clinical parameters and virological markers (HDV RNA, HBV DNA, HBsAg, HBcrAg, anti-HBc IgG) at treatment weeks 24 (TW24) and 48 (TW48). Additionally, full-genome HDV sequencing and a phylogenetic analysis were performed. Finally, analyses of the HDAg protein sequence and HDV RNA secondary structure were conducted to evaluate potential associations with treatment response. Results: A significant reduction in HDV RNA levels was observed at TW48, with a virological response (HDV RNA undetectable or ≥2 Log decline from BL) achieved by 58% of patients. Median BL levels of anti-HBc IgG were significantly different between virological responders (39.3 COI; interquartile range [IQR] 31.6–47.1) and virological non-responders (244.7 COI; IQR 127.0–299.4) (p = 0.0001). HDV genotype 1e was predominant across the cohort, and no specific HDAg polymorphisms predicted the response. However, secondary structure analysis of HDV RNA revealed that a specific pattern of internal loops in the region 63–100 nucleotides downstream of the editing site may influence treatment response by impacting editing efficacy. Conclusions: This study revealed key factors influencing BLV efficacy in HBV/HDV coinfection. Lower baseline anti-HBc IgG levels strongly correlated with a positive virological response, suggesting that the liver’s inflammatory state affects treatment success. Additionally, the analysis of HDV RNA secondary structure in patients receiving BLV treatment revealed a higher editing efficiency in virological responders, highlighting areas for further research. Full article

Background: The World Health Organization (WHO) recommends hepatitis D virus (HDV) screening among hepatitis B virus (HBV) infected individuals, with a focus on priority populations in resource-limited settings like Nigeria. HDV infection is a growing public health challenge, particularly among individuals with chronic hepatitis B virus (HBV) infection. HDV accelerates liver disease progression and significantly increases the risk of cirrhosis and hepatocellular carcinoma. Despite this, the epidemiology of HDV in Nigeria remains inadequately documented. This scoping review critically evaluates the prevalence, risk factors, and clinical outcomes of HDV co-infection among HBV patients in Nigeria. Method: We conducted a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. The review included observational cross-sectional studies published between 2009 and 2024. We focused on studies that used Immunoglobulin G (IgG) antibody testing or RNA-based diagnostics to assess HDV prevalence. We included PubMed, Google Scholar, and Dimensions databases due to their broad indexing and coverage of peer-reviewed articles and accessibility. We screened the studies for their relevance to HDV prevalence, risk factors, and clinical outcomes, while excluding those that only tested for IgM or HDV antigen. Eleven studies, with a combined sample size of 2308 participants, were included in the final analysis. We performed a narrative synthesis of the findings, considering geographic, gender, and age-based variations in HDV prevalence and clinical impact. Results: HDV prevalence among HBV-infected individuals in Nigeria ranged from 2.0% to 31.6%. The highest prevalence was reported in the Southwest (31.6%) among malaria patients, while lower rates were observed in the Southeast (2.8%). Prevalence was higher in males, particularly those aged 21–30 years in the Southwest and 31–40 years in other regions. RNA-based testing provided more accurate data on active viremia, with viremic HDV prevalence rates ranging from 3.2% to 16%. Triple infection with HIV/HBV/HDV was associated with significantly lower CD4+ cell counts and worse clinical outcomes, including elevated liver enzymes and rapid progression to liver cancer. Key risk factors for HDV co-infection included multiple sexual partners, sharing of needles, and unsafe medical practices. Co-infected patients demonstrated worse clinical outcomes, such as elevated liver enzymes, decompensated cirrhosis, and higher rates of hepatocellular carcinoma. Conclusions: Our review underscores the urgent need for routine HDV screening among HBV patients in Nigeria, especially given the severe clinical consequences of co-infection. The recent WHO guidelines recommending HDV screening align with our findings, which emphasize the importance of RNA-based HDV testing among HBV-positive patients to improve diagnostic accuracy. Public health efforts should prioritize tailored interventions based on geographic, age, and gender disparities in HDV prevalence. Triple infection with HIV/HBV/HDV requires integrated care models to address both immune suppressions as indicated by diminished CD4 cell count and liver disease progression, as these patients face worse outcomes. Targeted HDV screening in mostly affected demographics and geographies and improved Nigeria capacity for cheaper HDV RNA/PCR diagnostics can reduce liver-related morbidity and mortality caused by HBV, which can be worsened and accelerated by HDV coinfection. Full article

More than 12 million individuals worldwide are chronically infected with the hepatitis D virus (HDV). HDV infection is the most severe form of viral hepatitis since it requires hepatitis B virus co-infection and accelerates progression to cirrhosis and hepatocellular carcinoma. Therefore, treatment modalities to slow the progression of the disease are essential but not yet available. In addition, no antiviral treatment to date has been shown to reliably eradicate HDV. Pegylated interferon (PEG-IFN) is the only universally used treatment to suppress HDV RNA replication and improve liver inflammation and fibrosis. This treatment can be completed in 12–18 months, but cure rates remain low, and success does not reliably increase with the addition of a nucleos(t)ide analog. PEG-IFN therapy is also limited by poor tolerability and multiple adverse effects, including neutropenia, thrombocytopenia, and neuropsychiatric symptoms. Newer antiviral therapies in development target unique aspects of HDV viral replication and show promising results in combination with PEG-IFN for long-term HDV RNA suppression. These newer antiviral therapies include buleviritide (which blocks HDV entry), lonafarnib (which prevents HDV assembly), and REP-2139 (which prevents HDV export). In this manuscript, we discuss the characteristics of HDV infection and review the new antiviral therapies approved for treatment and those under investigation. Full article

The hepatitis D virus (HDV) superinfection of individuals with chronic hepatitis B virus (HBV) infection causes severe liver damage and the poorest long-term prognosis among viral hepatitis. This is attributed to the unique pathogenic mechanisms of HDV characterized by a direct cytopathic effect on hepatocytes and a significant impairment of the host immune response. The HDV genotype largely influences the extent of the pathogenic mechanisms with consequences on disease progression towards cirrhosis, liver decompensation, or hepatocellular carcinoma. In this context, identifying the circulating HDV genotypes in European regions with high prevalence, such as Romania, is crucial for effectively managing the long-term liver health. Here, we report the first comprehensive HDV study in Romania that clinically characterizes 82 patients and performs HDV genotyping by combining the nested-PCR reaction with sequencing analysis in 49 samples with an HDV-RNA load higher than 5000 IU/mL. While all isolates in our study belong to the HDV-1 genotype, the phylogenetic analysis based on sequence data from GenBank reveals the presence of the following potential three groups: (i) Italy and France; (ii) Spain; and (iii) Turkey, Iran, Pakistan, and Germany. This broad clustering highlights the recent surge in migration to and from Western Europe and the Middle East. Equally important, no differences in viral markers, clinical and paraclinical parameters, or treatment options were observed between these identified clusters. Nevertheless, this study considerably advances the understanding of hepatitis D epidemiology and clinical aspects in Romania. Full article

Hepatitis delta virus (HDV) infection is the most severe form of viral hepatitis. Genotype 1 (HDV-1) is by far the most prevalent in Europe and globally, while HDV-5 predominates in Western Africa. Data about HDV seroprevalence in Portugal are scarce and genotyping studies have not been performed yet. We aimed to assess the seroprevalence and genotypes of HDV in a large cohort of HBsAg-positive patients followed in our Hepatology Unit between 2012 and 2022. The anti-HDV-positive patients were subjected to a cross-sectional analysis, including blood sample collection for HDV RNA testing and genotype determination. In the cohort of HBsAg-positive patients, 57.5% (480/835) were born in African countries and 665/835 (79.6%) had been screened for anti-HDV antibodies. The HDV seroprevalence obtained was 6.5% (43/665). Twenty-one patients (age 41.2 ± 9.9 years; 57.1% male) were included in further molecular analyses. HDV RNA was positive in 8/21 (38.0%) and classified as HDV-5 in 7 patients (6 from Guinea-Bissau and 1 from Cape Verde) and HDV-1 in 1 patient (from Ukraine). In the largest and most comprehensive study performed in Portugal regarding HDV epidemiology to date, seroprevalence and genotype distribution of HDV (with predominance of HDV-5) were strongly influenced by immigration, notably from African countries. Full article

Hepatitis delta virus (HDV) is a satellite of hepatitis B virus (HBV), which requires the HBV surface antigen (HBsAg) for its assembly and propagation. Although countries affected by HBV infection in Africa are well identified, data on HDV infection are still scarce, like in Nigeria, where HBV infection is endemic. In this study, we aimed to determine the prevalence of HDV infection and identify the circulating genotypes/strains in the country. A nationwide study was performed on 1281 HBsAg-positive samples collected from patients across eleven sites drawn from the six geopolitical zones in Nigeria. Anti-HDV antibody (HDV-Ab) screening and HDV-RNA viral load quantification were performed using a commercial ELISA assay and real-time RT-PCR kit, respectively. HDV genotyping was performed by the Sanger sequencing of amplicons from the so-called R0 region of the viral genome, followed by phylogenetic analyses. Of the 1281 HBsAg-positive samples, 61 (4.8%) were HDV-Ab positive, among which, 12 (19.7%) were HDV-RNA positive. Genotypes were obtained for nine of them: seven “African” HDV-1, one “Asian/European” HDV-1 and one HDV-6. This study shows that Nigeria is a country of low HDV prevalence where mainly “African” genotype-1 strains are circulating. Full article

This study assesses the prevalence of hepatitis D virus (HDV) in people living with HIV (PLWHIV) in Greece. Given the compounding effects of HDV and hepatitis B (HBV) on liver disease progression, as well as the emergence of new therapeutic options such as bulevirtide, understanding regional disparities and the epidemiological impact of such co-infections is vital. A cross-sectional analysis was conducted utilizing 696 serum samples from PLWHIV attending five major university hospitals. The methodology included HDV antibody detection by ELISA and HDV RNA confirmation. Of the 30 HBsAg-positive samples analyzed, the study population was primarily male (93%), with a median age of 54 years. Participants had been on antiretroviral therapy for a median of 10 years, and the median CD4 count was 738 (539–1006) copies/mL. Additional serological findings revealed a 7% prevalence of hepatitis C virus (HCV) IgG antibodies and a 55% prevalence of hepatitis A virus (HAV) IgG antibodies. Seroreactivity for syphilis (RPR/VDRL/TPHA positive) was identified in 33% of the participants. The results indicated a low HDV prevalence, with only one individual (3%) testing positive for anti-HDV IgG antibodies and none for HDV RNA. This indicates a lower prevalence of HDV among PLWHIV with chronic HBV in Greece compared to global data. Full article

Previous studies reported that the hepatitis C virus (HCV) could help disseminate the hepatitis D virus (HDV) in vivo through the unrelated hepatitis B virus (HBV), but with essentially inconclusive results. To try to shed light on this still-debated topic, 146 anti-HCV-positive subjects (of whom 91 HCV/HIV co-infected, and 43 with prior HCV eradication) were screened for anti-HDV antibodies (anti-HD), after careful selection for negativity to any serologic or virologic marker of current or past HBV infection. One single HCV/HIV co-infected patient (0.7%) tested highly positive for anti-HD, but with no positive HDV-RNA. Her husband, in turn, was a HCV/HIV co-infected subject with a previous contact with HBV. While conducting a thorough review of the relevant literature, the authors attempted to exhaustively describe the medical history of both the anti-HD-positive patient and her partner, believing it to be the key to dissecting the possible complex mechanisms of HDV transmission from one subject to another, and speculating that in the present case, it may have been HCV itself that behaved as an HDV helper virus. In conclusion, this preliminary research, while needing further validation in large prospective studies, provided some further evidence of a role of HCV in HDV dissemination in humans. Full article

The human hepatitis delta virus (HDV) is a satellite RNA virus that depends on hepatitis B virus (HBV) surface proteins (HBsAg) to assemble into infectious virions targeting the same organ (liver) as HBV. Until recently, the evolutionary origin of HDV remained largely unknown. The application of bioinformatics on whole sequence databases lead to discoveries of HDV-like agents (DLA) and shed light on HDV’s evolution, expanding our understanding of HDV biology. DLA were identified in heterogeneous groups of vertebrates and invertebrates, highlighting that the evolution of HDV, represented by eight distinct genotypes, is broader and more complex than previously foreseen. In this study, we focused on the characterization of three mammalian DLA discovered in woodchuck (Marmota monax), white-tailed deer (Odocoileus virginianus), and lesser dog-like bat (Peropteryx macrotis) in terms of replication, cell-type permissiveness, and spreading pathways. We generated replication-competent constructs expressing 1.1-fold over-length antigenomic RNA of each DLA. Replication was initiated by transfecting the cDNAs into human (HuH7, HeLa, HEK293T, A549) and non-human (Vero E6, CHO, PaKi, LMH) cell lines. Upon transfection and replication establishment, none of the DLA expressed a large delta antigen. A cell division-mediated viral amplification assay demonstrated the capability of non-human DLA to replicate and propagate in hepatic and non-hepatic tissues, without the requirement of envelope proteins from a helper virus. Remarkably L-HDAg but not S-HDAg from HDV can artificially mediate envelopment of WoDV and DeDV ribonucleoproteins (RNPs) by HBsAg to form infectious particles, as demonstrated by co-transfection of HuH7 cells with the respective DLA expression constructs and a plasmid encoding HBV envelope proteins. These chimeric viruses are sensitive to HDV entry inhibitors and allow synchronized infections for comparative replication studies. Our results provide a more detailed understanding of the molecular biology, evolution, and virus–host interaction of this unique group of animal viroid-like agents in relation to HDV. Full article

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. Full article