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BACKGROUND & AIMS: Hepatitis E virus (HEV), primarily genotype 1 (HEV-1), causes approximately 20.1 million infections, 44,000 deaths, and 3000 stillbirths annually. Current evidence indicates that HEV-1 is only transmitted in humans. Here, we evaluated whether Mongolian gerbils can serve as animal models for HEV-1 infection. METHODS: Mongolian gerbils were used for HEV-1 and hepatitis E virus genotype 3 infection experiments. HEV infection parameters, including detection of HEV RNA and HEV antigen, liver function assessment, and histopathology, were evaluated. RESULTS: We adapted a clinical isolate of HEV-1 for Mongolian gerbils by serial passaging in feces of aged male gerbils. The gerbil-adapted strain obtained at passage 3 induced a robust, acute HEV infection, characterized by stable fecal virus shedding, elevated liver enzymes, histopathologic changes in the liver, and seroconversion to anti-HEV. An infectious complementary DNA clone of the adapted virus was generated. HEV-1-infected pregnant gerbils showed a high rate of maternal mortality and vertical transmission. HEV RNA or antigens were detected in the liver, kidney, intestine, placenta, testis, and fetus liver. Liver and placental transcriptomic analyses indicated activation of host immunity. Tacrolimus prolonged HEV-1 infection, whereas ribavirin cleared infection. The protective efficacy of a licensed HEV vaccine was validated using this model. CONCLUSIONS: HEV-1 efficiently infected Mongolian gerbils. This HEV-1 infection model will be valuable for investigating hepatitis E immunopathogenesis and evaluating vaccines and antivirals against HEV.
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Modelos Animales de Enfermedad , Genotipo , Gerbillinae , Virus de la Hepatitis E , Hepatitis E , Inmunocompetencia , Hígado , ARN Viral , Animales , Virus de la Hepatitis E/genética , Virus de la Hepatitis E/patogenicidad , Virus de la Hepatitis E/inmunología , Hepatitis E/virología , Hepatitis E/inmunología , Hepatitis E/transmisión , Masculino , Femenino , ARN Viral/aislamiento & purificación , ARN Viral/análisis , Hígado/virología , Hígado/patología , Heces/virología , Embarazo , Transmisión Vertical de Enfermedad Infecciosa , Antivirales/uso terapéutico , Antivirales/farmacología , Esparcimiento de Virus , Ribavirina/uso terapéutico , Ribavirina/farmacología , Complicaciones Infecciosas del Embarazo/virología , Complicaciones Infecciosas del Embarazo/inmunologíaRESUMEN
Hepatitis E virus (HEV) infection in pregnant women has a high incidence of developing fulminant hepatic failure (FHF) with significant mortality. Multiple amino acid changes in genotype 1 HEV (HEV-1) are reportedly linked to FHF clinical cases, but experimental confirmation of the roles of these changes in FHF is lacking. By utilizing the HEV-1 indicator replicon and infectious clone, we generated 11 HEV-1 single mutants, each with an individual mutation, and investigated the effect of these mutations on HEV replication and infection in human liver cells. We demonstrated that most of the mutations actually impaired HEV-1 replication efficiency compared with the wild type (WT), likely due to altered physicochemical properties and structural conformations. However, two mutations, A317T and V1120I, significantly increased HEV-1 replication. Notably, these two mutations simultaneously occurred in 100% of 21 HEV-1 variants from patients with FHF in Bangladesh. We further created an HEV-1 A317T/V1120I double mutant and found that it greatly enhanced HEV replication, which may explain the rapid viral replication and severe disease. Furthermore, we tested the effect of these FHF-associated mutations on genotype 3 HEV (HEV-3) replication and found that all the mutants had a reduced level of replication ability and infectivity, which is not unexpected due to distinct infection patterns between HEV-1 and HEV-3. Additionally, we demonstrated that these FHF-associated mutations do not appear to alter their sensitivity to ribavirin (RBV), suggesting that ribavirin remains a viable option for antiviral therapy for patients with FHF. The results have important implications for understanding the mechanism of HEV-1-associated FHF.
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Virus de la Hepatitis E , Hepatitis E , Fallo Hepático Agudo , Femenino , Genotipo , Hepatitis E/genética , Virus de la Hepatitis E/genética , Humanos , Fallo Hepático Agudo/virología , Mutación , Embarazo , Ribavirina , Replicación ViralRESUMEN
Hepatitis E virus (HEV) is an important but understudied zoonotic virus causing both acute and chronic viral hepatitis. A proportion of HEV-infected individuals also developed neurological diseases such as Guillain-Barré syndrome, neuralgic amyotrophy, encephalitis, and myelitis, although the mechanism remains unknown. In this study, by using an in vitro blood-brain barrier (BBB) model, we first investigated whether HEV can cross the BBB and whether the quasi-enveloped HEV virions are more permissible to the BBB than the nonenveloped virions. We found that both quasi-enveloped and nonenveloped HEVs can similarly cross the BBB and that addition of proinflammatory cytokine tumor necrosis factor alpha (TNF-α) has no significant effect on the ability of HEV to cross the BBB in vitro. To explore the possible mechanism of HEV entry across the BBB, we tested the susceptibility of human brain microvascular endothelial cells lining the BBB to HEV infection and showed that brain microvascular endothelial cells support productive HEV infection. To further confirm the in vitro observation, we conducted an experimental HEV infection study in pigs and showed that both quasi-enveloped and nonenveloped HEVs invade the central nervous system (CNS) in pigs, as HEV RNA was detected in the brain and spinal cord of infected pigs. The HEV-infected pigs with detectable viral RNA in CNS tissues had histological lesions in brain and spinal cord and significantly higher levels of proinflammatory cytokines TNF-α and interleukin 18 than the HEV-infected pigs without detectable viral RNA in CNS tissues. The findings suggest a potential mechanism of HEV-associated neuroinvasion.
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Barrera Hematoencefálica , Sistema Nervioso Central , Virus de la Hepatitis E , Hepatitis E , Animales , Barrera Hematoencefálica/virología , Sistema Nervioso Central/virología , Células Endoteliales/virología , Hepatitis E/virología , Virus de la Hepatitis E/patogenicidad , Humanos , ARN Viral/genética , Porcinos , Factor de Necrosis Tumoral alfa/metabolismoRESUMEN
Acute hepatitis E virus infection is a serious global health problem, which a significant cause of morbidity and mortality. The aim of the present study was to characterise the clinical features and therapeutic response of patients with acute HEV infection and identify risk factors for poor prognosis. In a retrospective study from 01 January 2014 to 01 Januray 2022, we collected baseline data from all patients eligible for acute hepatitis E virus (HEV) infection and followed up with all patients via interviews and medical records. We explored the clinical feature of Chinese patients with acute HEV infection. The follow-up data of patients were used to identify risk factors for poor prognosis. In total, 628 acute hepatitis E (AHE) patients fulfilled the inclusion criteria and did not meet the exclusion criteria. Among them, 452 were males and 176 were females (M:F = 2.57:1). The median age at diagnosis was 57.0 years (interquartile range: 46-64 years). The median baseline serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and total bilirubin (TBIL) were elevated in this cohort (642.3 U/L, 216.2 U/L, 104.1 µmol/L, respectively). The median hospitalisation duration was 16 days. Compared with patients without other liver diseases, patients with liver cirrhosis show lower baseline ALT and AST level, poorer coagulation indices and higher MELD scores. According to multivariate analysis, liver cirrhosis, high MELD score, low albumin concentration was found to be independent predictors of poor prognosis in patients with AHE. Our study used a lager sample size to validate that some demographic and serological features were quite different between patients with/without CLDs. Liver cirrhosis was a significant independent predictor of poor prognosis in acute HEV hepatitis.
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Hepatitis E virus (HEV) is a foodborne virus transmitted through the faecal-oral route that causes viral hepatitis in humans worldwide. Ever since its discovery as a zoonotic agent, HEV was isolated from several species with an expanding range of hosts. HEV possesses several features of other RNA viruses but also has certain HEV-specific traits that make its viral-host interactions inimitable. HEV leads to severe morbidity and mortality in immunocompromised people and pregnant women across the world. The situation in underdeveloped countries is even more alarming. Even after creating a menace across the world, we still lack an effective vaccine against HEV. Till date, there is only one licensed vaccine for HEV available only in China. The development of an anti-HEV vaccine that can reduce HEV-induced morbidity and mortality is required. Live attenuated and killed vaccines against HEV are not accessible due to the lack of a tolerant cell culture system, slow viral replication kinetics and varying growth conditions. Thus, the main focus for anti-HEV vaccine development is now on the molecular approaches. In the current study, we have designed a multi-epitope vaccine against HEV through a reverse vaccinology approach. For the first time, we have used viral ORF3, capsid protein and polyprotein altogether for epitope prediction. These are crucial for viral replication and persistence and are major vaccine targets against HEV. The proposed in silico vaccine construct comprises of highly immunogenic and antigenic T-cell and B-cell epitopes of HEV proteins. The construct is capable of inducing an effective and long-lasting host immune response as evident from the simulation results. In addition, the construct is stable, non-allergic and antigenic for the host. Altogether, our findings suggest that the in silico vaccine construct may be useful as a vaccine candidate for preventing HEV infections.
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Simulación por Computador , Hepatitis E , Vacunas de Subunidades Proteicas , Vacunas contra Hepatitis Viral , Humanos , Epítopos/inmunología , Epítopos/genética , Epítopos de Linfocito B/inmunología , Epítopos de Linfocito B/genética , Epítopos de Linfocito T/inmunología , Epítopos de Linfocito T/genética , Hepatitis E/prevención & control , Hepatitis E/inmunología , Virus de la Hepatitis E/inmunología , Virus de la Hepatitis E/genética , Vacunas de Subunidades Proteicas/inmunología , Desarrollo de Vacunas , Vacunas contra Hepatitis Viral/inmunología , Proteínas Virales/inmunología , Proteínas Virales/genéticaRESUMEN
Hepatitis E virus (HEV) infection in pregnant women is associated with a wide spectrum of adverse consequences for both mother and fetus. The high mortality in this population appears to be associated with hormonal changes and consequent immunological changes. This study conducted an analysis of immune responses in pregnant women infected with HEV manifesting varying severity. Data mining analysis of the GSE79197 was utilized to examine differentially biological functions in pregnant women with HEV infection (P-HEV) versus without HEV infection (P-nHEV), P-HEV progressing to ALF (P-ALF) versus P-HEV, and P-HEV versus non-pregnant women with HEV infection (nP-HEV). We found cellular response to interleukin and immune response-regulating signalings were activated in P-HEV compared with P-nHEV. However, there was a significant decrease of immune responses, such as T cell activation, leukocyte cell-cell adhesion, regulation of lymphocyte activation, and immune response-regulating signaling pathway in P-ALF patient than P-HEV patient. Compared with nP-HEV, MHC protein complex binding function was inhibited in P-HEV. Further microRNA enrichment analysis showed that MAPK and T cell receptor signaling pathways were inhibited in P-HEV compared with nP-HEV. In summary, immune responses were activated during HEV infection while being suppressed when developing ALF during pregnancy, heightening the importance of immune mediation in the pathogenesis of severe outcome in HEV infected pregnant women.
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Virus de la Hepatitis E , Hepatitis E , Complicaciones Infecciosas del Embarazo , Humanos , Femenino , Embarazo , Hepatitis E/inmunología , Hepatitis E/virología , Complicaciones Infecciosas del Embarazo/virología , Complicaciones Infecciosas del Embarazo/inmunología , Virus de la Hepatitis E/inmunología , Transducción de Señal , Fallo Hepático Agudo/inmunología , Fallo Hepático Agudo/virología , MicroARNs/genética , AdultoRESUMEN
Recently, hepatitis E virus (HEV, Paslahepevirus balayani) particles were detected for the first time in the ejaculate of two chronically infected patients. Since then, we have been able to detect HEV in ejaculate in five further patients, and thus in a total of seven out of nine (78%) chronically infected men (age 36-67 years, median 56 years). In five patients, the HEV RNA concentration was more than 100-fold higher compared to the serum, while in two patients, the viral load was more than 10-fold lower. However, it has remained unclear whether viral particles shed in the ejaculate were infectious, as a previous cell culture model had failed to demonstrate the infectivity. In the current study, we employed an optimized HEV cell culture system based on overconfluent PLC/PRF/5 cells to investigate the infectivity of HEV particles from ejaculate and other body fluids. With this approach, we were able to show for the first time that HEV particles in the ejaculate from several patients were infectious. HEV replicated to high viral loads of 1e9 HEV RNA copies per ml. This indicates that HEV-positive ejaculate could bear a risk of infection for sexual partners.
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Virus de la Hepatitis E , Hepatitis E , ARN Viral , Carga Viral , Humanos , Virus de la Hepatitis E/aislamiento & purificación , Persona de Mediana Edad , Hepatitis E/virología , Masculino , Adulto , Anciano , ARN Viral/análisis , Semen/virología , Virión , Línea Celular , Esparcimiento de VirusRESUMEN
The hepatitis E virus (HEV) is a major cause of acute viral hepatitis worldwide. HEV is classified into eight genotypes, labeled HEV-1 through HEV-8. Genotypes 1 and 2 exclusively infect humans, while genotypes 3, 4, and 7 can infect both humans and animals. In contrast, genotypes 5, 6, and 8 are restricted to infecting animals. While most individuals with a strong immune system experience a self-limiting infection, those who are immunosuppressed may develop chronic hepatitis. Pregnant women are particularly vulnerable to severe illness and mortality due to HEV infection. In addition to liver-related complications, HEV can also cause extrahepatic manifestations, including neurological disorders. The immune response is vital in determining the outcome of HEV infection. Deficiencies in T cells, NK cells, and antibody responses are linked to poor prognosis. Interestingly, HEV itself contains microRNAs that regulate its replication and modify the host's antiviral response. Diagnosis of HEV infection involves the detection of HEV RNA and anti-HEV IgM/IgG antibodies. Supportive care is the mainstay of treatment for acute infection, while chronic HEV infection may be cleared with the use of ribavirin and pegylated interferon. Prevention remains the best approach against HEV, focusing on sanitation infrastructure improvements and vaccination, with one vaccine already licensed in China. This comprehensive review provides insights into the spread, genotypes, prevalence, and clinical effects of HEV. Furthermore, it emphasizes the need for further research and attention to HEV, particularly in cases of acute hepatitis, especially among solid-organ transplant recipients.
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Genotipo , Virus de la Hepatitis E , Hepatitis E , Hepatitis E/tratamiento farmacológico , Hepatitis E/virología , Hepatitis E/epidemiología , Hepatitis E/inmunología , Virus de la Hepatitis E/genética , Virus de la Hepatitis E/inmunología , Humanos , Animales , Antivirales/uso terapéuticoRESUMEN
Hepatitis E virus (HEV) is a positive-sense, single-stranded RNA virus and causes primarily acute self-limiting infections. The ORF1 of the HEV genome encodes a polyprotein around 190 kDa, which contains several putative domains, including helicase and RNA-dependent RNA polymerase. The HEV-encoded helicase is a member of the superfamily 1 helicase family and possesses multiple enzymatic functions, such as RNA 5'-triphosphatase, RNA unwinding, and NTPase, which are thought to contribute to viral RNA synthesis. However, the helicase interaction with cellular proteins remains less known. Oxysterol binding protein (OSBP) is a lipid regulator that shuffles between the Golgi apparatus and the endoplasmic reticulum for cholesterol and phosphatidylinositol-4-phosphate exchange and controls the efflux of cholesterol from cells. In this study, the RNAi-mediated silencing of OSBP significantly reduced HEV replication. Further studies indicate that the HEV helicase interacted with OSBP, shown by co-immunoprecipitation and co-localization in co-transfected cells. The presence of helicase blocked OSBP preferential translocation to the Golgi apparatus. These results demonstrate that OSBP contributes to HEV replication and enrich our understanding of the HEV-cell interactions.
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Aparato de Golgi , Virus de la Hepatitis E , Receptores de Esteroides , Replicación Viral , Virus de la Hepatitis E/fisiología , Virus de la Hepatitis E/genética , Receptores de Esteroides/metabolismo , Receptores de Esteroides/genética , Humanos , Aparato de Golgi/metabolismo , Aparato de Golgi/virología , Interacciones Huésped-Patógeno , Línea Celular , Unión Proteica , Hepatitis E/virología , Hepatitis E/metabolismoRESUMEN
To date, no studies comparing the prevalence of hepatitis E virus (HEV) infection between the general and human immunodeficiency virus 2 (HIV-2) populations are available. With the purpose of filling this gap, this prevalence was assessed in the HIV-2 population from central Portugal. HEV seropositivity was 19.4%, which did not differ significantly from that found in the matched control population, and was not associated with CD4 cell count, HIV-2 viral load, and geographic origin or travel history to regions considered highly endemic for HEV. The results suggest that HIV-2 is not a risk factor for HEV infection, neither for an increased occurrence of chronic HEV infection.
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BACKGROUND: Acute hepatitis E infection (HEV), with its high incidence in Europe, should be considered as a differential diagnosis of acute viral hepatitis and can in some cases manifest with pronounced neurological symptoms. CLINICAL CASE: We report on a 33-year-old female patient with severe arthralgia, myalgia, headache and psychomotor deterioration. Laboratory analyses showed elevated transaminases without signs of cholestasis. Acute hepatitis E virus infection was detected in serum. She reported fatigue and dysesthesias not responsive to analgesics. Cerebrospinal fluid (CSF) analysis revealed an inflammatory syndrome. HEV RNA was detected in the CSF. The infection remained mild, but dysesthesias persisted. Eight weeks after the first admission, the symptoms worsened again. Complete and sustained remission was achieved following intravenous corticosteroid treatment. CONCLUSION: In patients with acute neurological symptoms and liver enzyme elevation, HEV infection should be considered. Neurologic symptoms such as fatigue, arthralgia, myalgia and dysesthesia along with psychomotor retardation should prompt CSF analysis.
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Hepatitis E virus (HEV) is the major pathogen of viral hepatitis. Immunocompromised individuals infected by HEV are prone to chronic hepatitis and increase the risk of hepato-cellular carcinoma (HCC). Inhibitor of growth family member 5 (ING5) is a tumor suppressor that is expressed at low levels in cancer tumors or cells. However, the underlying relationship between ING5 and HEV infection is unclear. In the present study, acute and chronic HEV animal models are used to explore the interaction between ING5 and HEV. Notably, the expression of ING5 is significantly increased in both the livers of acute HEV-infected BALB/c mice and chronic HEV-infected rhesus macaques. In addition, the relationship between HEV infection and ING5 expression is further identified in human hepatoma (HepG-2) cells. In conclusion, HEV infection strongly upregulates ING5 expression both in vivo and in vitro, which has significant implications for further understanding the pathogenic mechanism of HEV infection.
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Hepatitis E , Macaca mulatta , Ratones Endogámicos BALB C , Proteínas Supresoras de Tumor , Regulación hacia Arriba , Animales , Humanos , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismo , Hepatitis E/virología , Hepatitis E/metabolismo , Hepatitis E/genética , Ratones , Virus de la Hepatitis E/genética , Células Hep G2 , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Hígado/metabolismo , Hígado/virología , Modelos Animales de EnfermedadRESUMEN
Hepatitis E virus (HEV) is the causative agent of foodborne infections occurring in high income countries mainly by consumption of undercooked and raw pork products. The virus is zoonotic with pigs and wild boars as the main reservoirs. Several studies proved the presence of HEV-RNA in pork liver sausages, pâté and other pork by-products. However, the detection of HEV nucleic acids does not necessary correspond to infectious virus and information on the persistence of the virus in the food is still limited. To which extent and how long the virus can survive after conventional industrial and home-made conservation and cooking procedures is largely unknown. In the present study, we investigated the persistence of two subtypes of HEV-3, by measuring the viral RNA on cell supernatant of infected A549 cells, after long-term storage at +4 °C and -20 °C and after heating for short or long-time span. Results confirmed that either low temperature storage (+4 °C) or freezing (-20 °C) do not influence the survival of the virus, and only a moderate reduction of presence of its RNA after 12 weeks at +4 °C was observed. To the other side, heating at 56 °C for long time (1 h) or at higher temperatures (>65 °C) for shorter time inactivated the virus successfully.
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Virus de la Hepatitis E , Hepatitis E , Productos de la Carne , Enfermedades de los Porcinos , Porcinos , Animales , Virus de la Hepatitis E/genética , Calor , ARN Viral/genética , Filogenia , Sus scrofaRESUMEN
Hepatitis E virus (HEV) infection is typically a self-limiting, acute illness that spreads through the gastrointestinal tract but replicates in the liver. However, chronic infections are possible in immunocompromised individuals. The HEV virion has two shapes: exosome-like membrane-associated quasi-enveloped virions (eHEV) found in circulating blood or in the supernatant of infected cell cultures and non-enveloped virions ("naked") found in infected hosts' feces and bile to mediate inter-host transmission. Although HEV is mainly spread via enteric routes, it is unclear how it penetrates the gut wall to reach the portal bloodstream. Both virion types are infectious, but they infect cells in different ways. To develop personalized treatment/prevention strategies and reduce HEV impact on public health, it is necessary to decipher the entry mechanism for both virion types using robust cell culture and animal models. The contemporary knowledge of the cell entry mechanism for these two HEV virions as possible therapeutic target candidates is summarized in this narrative review.
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Virus de la Hepatitis E , Hepatitis E , Humanos , Virus de la Hepatitis E/fisiología , Virus de la Hepatitis E/patogenicidad , Hepatitis E/transmisión , Hepatitis E/virología , Virión/fisiología , AnimalesRESUMEN
Background & Objective: Viral hepatitis is a major public health concern in low-middle income countries. Hepatitis-E infection (HEV) is found globally but most prevalent in low-income countries especially those with poor sanitation systems, access to clean drinking water and health services. Superinfection with HEV in patients with chronic liver disease (CLD) can cause severe hepatic decompensation leading to increased morbidity and mortality. To determine the frequency of seroprevalence of Hepatitis-E virus Immunoglobulin g (IgG) and its association with chronic liver disease. Methods: A cross-sectional study was conducted in Asian Institute of Medical Sciences, Hyderabad, Pakistan from January till May 2022. A total of 196 patients of aged ≥ 18 years, presenting in gastroenterology clinics were included in the study after informed consent. Result: Among 196 patients, one third of patient were male (73.5%). Out of which 162 (82.7%) had liver disease and 34 (17.3%) were without liver disease. The median age of patient was 45 (33-51) years. The overall seroprevalence of HEV IgG among study population was 69.4%. HEV IgG was present in 114 and 22 in CLD and non CLD patients respectively. Multivariable regression shows no association between seroprevalence of HEV in CLD and non-CLD patient (AOR 1.02, 95% CI 0.45-2.313). Conclusion: Our study showed high frequency of HEV seropositivity. No difference was observed in HEV seropositivity among CLD and non-CLD patients.
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Objective: To determine the etiologies and outcomes of liver disease in pregnancy in a developing country. Method: A total of 336 consecutive pregnant women with liver disease were included in this prospective cohort study conducted at the Department of Gastroenterology, Jinnah Postgraduate Medical Center, Karachi from August 2019 to August 2021. Patients' baseline demographic, clinical, and laboratory data and outcomes were collected on a pre-designed questionnaire. Results: Among all the pregnant females, the most common liver disease was acute hepatitis E virus (HEV) infection (37.2%), followed by preeclampsia (PEC)/eclampsia (EC), hemolysis, elevated liver enzymes & low platelets (HELLP) syndrome, and hyperemesis gravidarum (HG). The most common maternal complications were fulminant hepatic failure (FHF) in 14.9% and placental abruption in 11.0%. Fetal complications included intrauterine death (IUD) in 20.8% and preterm birth in 8.6%. The maternal and neonatal mortality rates were 11.6% and 39.6%, respectively. Among the predictors, low maternal weight, low body mass index (BMI), and low hemoglobin (Hb) were associated with increased maternal mortality. Low fetal weight, height, maternal systolic blood pressure (SBP), and low maternal Hb were independent predictors of fetal mortality. Conclusion: In our cohort of pregnant females in a tertiary care medical center, acute HEV was the most common liver disease, followed by PEC/EC, HELLP, and HG. Maternal and fetal deaths were alarming in this group of patients and demanded careful management.
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In a 3-year period, 38 of 48 persons testing positive for hepatitis E virus (HEV) immunoglobulin M in Los Angeles County did not meet the acute HEV case definition. Healthcare providers should restrict HEV serologic testing for persons with clinically compatible symptoms or epidemiologic risk factors.
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Virus de la Hepatitis E , Hepatitis E , Humanos , Hepatitis E/diagnóstico , Hepatitis E/epidemiología , Virus de la Hepatitis E/genética , Los Angeles/epidemiología , Inmunoglobulina M , Anticuerpos AntihepatitisRESUMEN
BACKGROUND & AIMS: Appropriate treatment options are lacking for hepatitis E virus (HEV)-infected pregnant women and immunocompromised individuals. Thus, we aimed to identify efficient anti-HEV drugs through high-throughput screening, validate them in vitro and in vivo (in a preclinical animal study), and elucidate their underlying antiviral mechanism of action. METHODS: Using appropriate cellular and rodent HEV infection models, we studied a critical pathway for host-HEV interactions and performed a preclinical study of the corresponding antivirals, which target proteostasis of the HEV replicase. RESULTS: We found 17 inhibitors that target HEV-HSP90 interactions by unbiased compound library screening on human hepatocytes harboring an HEV replicon. Inhibitors of HSP90 (iHSP90) markedly suppressed HEV replication with efficacy exceeding that of conventional antivirals (IFNα and ribavirin) in vitro. Mechanistically, iHSP90 treatment released the viral replicase ORF1 protein from the ORF1-HSP90 complex and triggered rapid ubiquitin/proteasome-mediated degradation of ORF1, resulting in abrogated HEV replication. Furthermore, a preclinical trial in a Mongolian gerbil HEV infection model showed this novel anti-HEV strategy to be safe, efficient, and able to prevent HEV-induced liver damage. CONCLUSIONS: In this study, we uncover a proteostatic pathway that is critical for host-HEV interactions and we provide a foundation from which to translate this new understanding of the HEV life cycle into clinically promising antivirals. IMPACT AND IMPLICATIONS: Appropriate treatment options for hepatitis E virus (HEV)-infected pregnant women and immunocompromised patients are lacking; hence, there is an urgent need for safe and effective HEV-specific therapies. This study identified new antivirals (inhibitors of HSP90) that significantly limit HEV infection by targeting the viral replicase for degradation. Moreover, these anti-HEV drugs were validated in an HEV rodent model and were found to be safe and efficient for prevention of HEV-induced liver injury in preclinical experiments. Our findings substantially promote the understanding of HEV pathobiology and pave the way for antiviral development.
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Virus de la Hepatitis E , Hepatitis E , Animales , Humanos , Femenino , Embarazo , Proteostasis , Proteinas del Complejo de Replicasa Viral , Hepatitis E/tratamiento farmacológico , Antivirales/farmacología , Antivirales/uso terapéutico , Proteínas Virales , Replicación ViralRESUMEN
Hepatitis E virus (HEV) is an emerging pathogen responsible for more than 20 million cases of acute hepatitis globally per annum. Healthy individuals typically have a self-limiting infection, but mortality rates in some populations such as pregnant women can reach 30â%. A detailed understanding of the virus lifecycle is lacking, mainly due to limitations in experimental systems. In this regard, the cyclophilins are an important family of proteins that have peptidyl-prolyl isomerase activity and play roles in the replication of a number of positive-sense RNA viruses, including hepatotropic viruses such as hepatitis C virus (HCV). Cyclophilins A and B (CypA/B) are the two most abundant Cyps in hepatocytes and are therefore potential targets for pan-viral therapeutics. Here, we investigated the importance of CypA and CypB for HEV genome replication using sub-genomic replicons. Using a combination of pharmacological inhibition by cyclosporine A (CsA), and silencing by small hairpin RNA we find that CypA and CypB are not essential for HEV replication. However, we find that silencing of CypB reduces replication of some HEV isolates in some cells. Furthermore, sensitivity to Cyp silencing appears to be partly conferred by the sequence within the hypervariable region of the viral polyprotein. These data suggest HEV is atypical in its requirements for cyclophilin for viral genome replication and that this phenomenon could be genotype- and sequence-specific.
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Hepatitis C , Virus de la Hepatitis E , Embarazo , Femenino , Humanos , Ciclofilinas/genética , Ciclofilinas/metabolismo , Virus de la Hepatitis E/genética , Hepacivirus/genética , Ciclosporina/farmacología , Replicación ViralRESUMEN
Hepatitis E virus (HEV) egresses from infected hepatocytes as quasienveloped particles containing open reading frame 3 (ORF3) protein. HEV ORF3 (small phosphoprotein) interacts with host proteins to establish a favourable environment for virus replication. It is a functional viroporin that plays an important role during virus release. Our study provides evidence that pORF3 plays a pivotal role in inducing Beclin1-mediated autophagy that helps HEV-1 replication as well as its exit from cells. The ORF3 interacts with host proteins involved in regulation of transcriptional activity, immune response, cellular and molecular processes, and modulation of autophagy, by interacting with proteins, DAPK1, ATG2B, ATG16L2 and also several histone deacetylases (HDACs). For autophagy induction, the ORF3 utilizes non-canonical NF-κB2 pathway and sequesters p52NF-κB and HDAC2 to upregulate DAPK1 expression, leading to enhanced Beclin1 phosphorylation. By sequestering several HDACs, HEV may prevent histone deacetylation to maintain overall cellular transcription intact to promote cell survival. Our findings highlight a novel crosstalk between cell survival pathways participating in ORF3-mediated autophagy.