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Inoue J, Weber D, Fernandes JF, Adegnika AA, Agnandji ST, Lell B, Kremsner PG, Grobusch MP, Mordmüller B, Held J. HHV-6 infections in hospitalized young children of Gabon. Infection 2023; 51:1759-1765. [PMID: 37501013 PMCID: PMC10665219 DOI: 10.1007/s15010-023-02077-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 07/15/2023] [Indexed: 07/29/2023]
Abstract
PURPOSE Fever is a common cause for hospitalization among the pediatric population. The spectrum of causative agents is diverse. Human herpesvirus 6 (HHV-6) is a ubiquitous virus that often causes hospitalization of children in western countries. Previously, we investigated the cause of fever of 600 febrile hospitalized children in Gabon, and in 91 cases the causative pathogen was not determined. In this study, we assessed HHV-6 infection as potential cause of hospitalization in this group. METHODS Blood samples were assessed for HHV-6 using real-time quantitative PCR. Three groups were investigated: (1) group of interest: 91 hospitalized children with febrile illness without a diagnosed causing pathogen; (2) hospitalized control: 91 age-matched children hospitalized with febrile illness with a potentially disease-causing pathogen identified; both groups were recruited at the Albert Schweitzer Hospital in Lambaréné, Gabon and (3) healthy control: 91 healthy children from the same area. RESULTS Samples from 273 children were assessed. Age range was two months to 14 years, median (IQR) age was 36 (12-71) months; 52% were female. HHV-6 was detected in 64% (58/91), 41% (37/91), and 26% (24/91) of the samples from groups 1, 2, and 3, respectively; with statistically significant odds of being infected with HHV-6 in group 1 (OR = 4.62, 95% CI [2.46, 8.90]). Only HHV-6B was detected. CONCLUSIONS Although tropical diseases account for a large proportion of children's hospitalizations, considering common childhood diseases such as HHV-6 when diagnosing febrile illnesses in pediatric populations in tropical countries is of importance.
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Affiliation(s)
- Juliana Inoue
- Institute of Tropical Medicine, Eberhard Karls University Tübingen, Tübingen, Germany
| | - David Weber
- Institute of Tropical Medicine, Eberhard Karls University Tübingen, Tübingen, Germany
| | - José Francisco Fernandes
- Institute of Tropical Medicine, Eberhard Karls University Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany
- Centre of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Amsterdam Infection & Immunity, Amsterdam Public Health, Amsterdam University Medical Centres, Location University of Amsterdam, Amsterdam, The Netherlands
| | - Ayola Akim Adegnika
- Institute of Tropical Medicine, Eberhard Karls University Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany
| | - Selidji Todagbe Agnandji
- Institute of Tropical Medicine, Eberhard Karls University Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany
| | - Bertrand Lell
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Department of Medicine I, Division of Infectious Diseases and Tropical Medicine, Medical University of Vienna, Vienna, Austria
| | - Peter G Kremsner
- Institute of Tropical Medicine, Eberhard Karls University Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany
| | - Martin Peter Grobusch
- Institute of Tropical Medicine, Eberhard Karls University Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Centre of Tropical Medicine and Travel Medicine, Department of Infectious Diseases, Amsterdam Infection & Immunity, Amsterdam Public Health, Amsterdam University Medical Centres, Location University of Amsterdam, Amsterdam, The Netherlands
- Institute of Infectious Diseases and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Masanga Medical Research Unit, Masanga, Sierra Leone
| | - Benjamin Mordmüller
- Institute of Tropical Medicine, Eberhard Karls University Tübingen, Tübingen, Germany
- Centre de Recherches Médicales de Lambaréné (CERMEL), Lambaréné, Gabon
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jana Held
- Institute of Tropical Medicine, Eberhard Karls University Tübingen, Tübingen, Germany.
- German Center for Infection Research (DZIF), Partner Site Tübingen, Tübingen, Germany.
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Oumarou Hama H, Aboudharam G, Barbieri R, Lepidi H, Drancourt M. Immunohistochemical diagnosis of human infectious diseases: a review. Diagn Pathol 2022; 17:17. [PMID: 35094696 PMCID: PMC8801197 DOI: 10.1186/s13000-022-01197-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 01/18/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Immunohistochemistry (IHC) using monoclonal and polyclonal antibodies is a useful diagnostic method for detecting pathogen antigens in fixed tissues, complementing the direct diagnosis of infectious diseases by PCR and culture on fresh tissues. It was first implemented in a seminal publication by Albert Coons in 1941. MAIN BODY Of 14,198 publications retrieved from the PubMed, Google, Google Scholar and Science Direct databases up to December 2021, 230 were selected for a review of IHC techniques, protocols and results. The methodological evolutions of IHC and its application to the diagnosis of infectious diseases, more specifically lice-borne diseases, sexually transmitted diseases and skin infections, were critically examined. A total of 59 different pathogens have been detected once in 22 different tissues and organs; and yet non-cultured, fastidious and intracellular pathogens accounted for the vast majority of pathogens detected by IHC. Auto-IHC, incorporating patient serum as the primary antibody, applied to diseased heart valves surgically collected from blood culture-negative endocarditis patients, detected unidentified Gram-positive cocci and microorganisms which were subsequently identified as Coxiella burnetii, Bartonella quintana, Bartonella henselae and Tropheryma whipplei. The application of IHC to ancient tissues dated between the ends of the Ptolemaic period to over 70 years ago, have also contributed to paleomicrobiology diagnoses. CONCLUSION IHC plays an important role in diagnostic of infectious diseases in tissue samples. Paleo-auto-IHC derived from auto-IHC, is under development for detecting non-identified pathogens from ancient specimens.
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Affiliation(s)
- Hamadou Oumarou Hama
- IHU Méditerranée Infection, Marseille, France
- Aix-Marseille-Univ., IRD, MEPHI, IHU Méditerranée Infection, Marseille, France
| | - Gérard Aboudharam
- Aix-Marseille-Univ., IRD, MEPHI, IHU Méditerranée Infection, Marseille, France
- Aix-Marseille-Univ., Ecole de Médecine Dentaire, Marseille, France
| | - Rémi Barbieri
- IHU Méditerranée Infection, Marseille, France
- Aix-Marseille-Univ., IRD, MEPHI, IHU Méditerranée Infection, Marseille, France
| | - Hubert Lepidi
- Aix-Marseille-Univ., IRD, MEPHI, IHU Méditerranée Infection, Marseille, France
- Laboratoire d'Histologie, Faculté de Médecine, Université de la Méditerranée, Marseille, France
| | - Michel Drancourt
- IHU Méditerranée Infection, Marseille, France.
- Aix-Marseille-Univ., IRD, MEPHI, IHU Méditerranée Infection, Marseille, France.
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Human Herpesvirus-6 and -7 in the Brain Microenvironment of Persons with Neurological Pathology and Healthy People. Int J Mol Sci 2021; 22:ijms22052364. [PMID: 33673426 PMCID: PMC7956495 DOI: 10.3390/ijms22052364] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/19/2021] [Accepted: 02/24/2021] [Indexed: 01/02/2023] Open
Abstract
During persistent human beta-herpesvirus (HHV) infection, clinical manifestations may not appear. However, the lifelong influence of HHV is often associated with pathological changes in the central nervous system. Herein, we evaluated possible associations between immunoexpression of HHV-6, -7, and cellular immune response across different brain regions. The study aimed to explore HHV-6, -7 infection within the cortical lobes in cases of unspecified encephalopathy (UEP) and nonpathological conditions. We confirmed the presence of viral DNA by nPCR and viral antigens by immunohistochemistry. Overall, we have shown a significant increase (p < 0.001) of HHV antigen expression, especially HHV-7 in the temporal gray matter. Although HHV-infected neurons were found notably in the case of HHV-7, our observations suggest that higher (p < 0.001) cell tropism is associated with glial and endothelial cells in both UEP group and controls. HHV-6, predominantly detected in oligodendrocytes (p < 0.001), and HHV-7, predominantly detected in both astrocytes and oligodendrocytes (p < 0.001), exhibit varying effects on neural homeostasis. This indicates a high number (p < 0.001) of activated microglia observed in the temporal lobe in the UEP group. The question remains of whether human HHV contributes to neurological diseases or are markers for some aspect of the disease process.
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Santpere G, Telford M, Andrés-Benito P, Navarro A, Ferrer I. The Presence of Human Herpesvirus 6 in the Brain in Health and Disease. Biomolecules 2020; 10:E1520. [PMID: 33172107 PMCID: PMC7694807 DOI: 10.3390/biom10111520] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/03/2020] [Accepted: 11/05/2020] [Indexed: 01/03/2023] Open
Abstract
The human herpesvirus 6 (HHV-6) -A and -B are two dsDNA beta-herpesviruses infectingalmost the entire worldwide population. These viruses have been implicated in multipleneurological conditions in individuals of various ages and immunological status, includingencephalitis, epilepsy, and febrile seizures. HHV-6s have also been suggested as playing a role inthe etiology of neurodegenerative diseases such as multiple sclerosis and Alzheimer's disease. Theapparent robustness of these suggested associations is contingent on the accuracy of HHV-6detection in the nervous system. The effort of more than three decades of researching HHV-6 in thebrain has yielded numerous observations, albeit using variable technical approaches in terms oftissue preservation, detection techniques, sample sizes, brain regions, and comorbidities. In thisreview, we aimed to summarize current knowledge about the entry routes and direct presence ofHHV-6 in the brain parenchyma at the level of DNA, RNA, proteins, and specific cell types, inhealthy subjects and in those with neurological conditions. We also discuss recent findings relatedto the presence of HHV-6 in the brains of patients with Alzheimer's disease in light of availableevidence.
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Affiliation(s)
- Gabriel Santpere
- Neurogenomics Group, Research Programme on Biomedical Informatics (GRIB), Hospital del Mar Medical Research Institute (IMIM), DCEXS, Universitat Pompeu Fabra, 08003 Barcelona, Catalonia, Spain
| | - Marco Telford
- Institute of Evolutionary Biology (UPF-CSIC), Departament de Ciències Experimentals i la Salut, Universitat Pompeu Fabra, PRBB, 08003 Barcelona, Catalonia, Spain; (M.T.); (A.N.)
| | - Pol Andrés-Benito
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain;
| | - Arcadi Navarro
- Institute of Evolutionary Biology (UPF-CSIC), Departament de Ciències Experimentals i la Salut, Universitat Pompeu Fabra, PRBB, 08003 Barcelona, Catalonia, Spain; (M.T.); (A.N.)
- Catalan Institution of Research and Advanced Studies (ICREA), Passeig de Lluís Companys 23, 08010 Barcelona, Spain
- Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Carrer del Dr. Aiguader 88, 08003 Barcelona, Spain
- Barcelonaβeta Brain Research Center (BBRC), Pasqual Maragall Foundation, Wellington 30, 08005 Barcelona, Spain
| | - Isidre Ferrer
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), 28031 Madrid, Spain;
- Department of Pathology and Experimental Therapeutics, University of Barcelona, Hospitalet de Llobregat, 08907 Barcelona, Spain
- Bellvitge University Hospital, IDIBELL (Bellvitge Biomedical Research Centre), Hospitalet de Llobregat, 08908 Barcelona, Spain
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Leibovitch EC, Caruso B, Ha SK, Schindler MK, Lee NJ, Luciano NJ, Billioux BJ, Guy JR, Yen C, Sati P, Silva AC, Reich DS, Jacobson S. Herpesvirus trigger accelerates neuroinflammation in a nonhuman primate model of multiple sclerosis. Proc Natl Acad Sci U S A 2018; 115:11292-11297. [PMID: 30322946 PMCID: PMC6217390 DOI: 10.1073/pnas.1811974115] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Pathogens, particularly human herpesviruses (HHVs), are implicated as triggers of disease onset/progression in multiple sclerosis (MS) and other neuroinflammatory disorders. However, the time between viral acquisition in childhood and disease onset in adulthood complicates the study of this association. Using nonhuman primates, we demonstrate that intranasal inoculations with HHV-6A and HHV-6B accelerate an MS-like neuroinflammatory disease, experimental autoimmune encephalomyelitis (EAE). Although animals inoculated intranasally with HHV-6 (virus/EAE marmosets) were asymptomatic, they exhibited significantly accelerated clinical EAE compared with control animals. Expansion of a proinflammatory CD8 subset correlated with post-EAE survival in virus/EAE marmosets, suggesting that a peripheral (viral?) antigen-driven expansion may have occurred post-EAE induction. HHV-6 viral antigen in virus/EAE marmosets was markedly elevated and concentrated in brain lesions, similar to previously reported localizations of HHV-6 in MS brain lesions. Collectively, we demonstrate that asymptomatic intranasal viral acquisition accelerates subsequent neuroinflammation in a nonhuman primate model of MS.
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Affiliation(s)
- Emily C Leibovitch
- Viral Immunology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Breanna Caruso
- Viral Immunology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Seung Kwon Ha
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Matthew K Schindler
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Nathanael J Lee
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Nicholas J Luciano
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Bridgette J Billioux
- Viral Immunology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Joseph R Guy
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Cecil Yen
- Cerebral Microcirculation Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Pascal Sati
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Afonso C Silva
- Cerebral Microcirculation Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Daniel S Reich
- Translational Neuroradiology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
| | - Steven Jacobson
- Viral Immunology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892;
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EBV and HHV-6 Circulating Subtypes in People Living with HIV in Burkina Faso, Impact on CD4 T cell count and HIV Viral Load. Mediterr J Hematol Infect Dis 2017; 9:e2017049. [PMID: 28894558 PMCID: PMC5584768 DOI: 10.4084/mjhid.2017.049] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 08/05/2017] [Indexed: 12/13/2022] Open
Abstract
Epstein Barr Virus (EBV) and Human Herpes Virus 6 (HHV-6) are responsible for severe diseases, particularly in immunocompromised persons. There is limited data of the infection of these opportunistic viruses in Burkina Faso. The purpose of this study was to characterize EBV and HHV-6 subtypes and to assess their impact on CD4 T cell count, HIV-1 viral load and antiretroviral treatment in people living with HIV-1. The study population consisted of 238 HIV-positive patients with information on the CD4 T cell count, HIV-1 viral load and HAART. Venous blood samples collected in EDTA tubes were used for EBV and HHV-6 Real Time PCR subtyping. An infection rate of 6.7% (16/238) and 7.1% (17/238) were found respectively for EBV and HHV-6 in the present study. Among EBV infections, similar prevalence was noted for both subtypes (3.9% (9/238) for EBV-1 vs 4.6% (11/238) for EBV-2) with 2.1% (5/238) of co-infection. HHV-6A infection represented 6.3% (15/238) of the study population against 5.0% (12/238) for HHV-6B. EBV-2 infection was significantly higher in patients with CD4 T cell count ≥ 500 compared to those with CD4 T cell count less than 500 cells (1.65% vs 8.56%, p = 0,011). The prevalence of EBV and HHV-6 infections was almost similar in HAART-naive and HAART-experienced patients. The present study provides information on the prevalence of EBV and HHV-6 subtypes in people living with HIV-1 in Burkina Faso. The study also suggests that HAART treatment has no effect on infection with these opportunistic viruses in people living with HIV-1.
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Abstract
Human roseoloviruses include three different species, human herpesviruses 6A, 6B, and 7 (HHV-6A, HHV-6B, HHV-7), genetically related to human cytomegalovirus. They exhibit a wide cell tropism in vivo and, like other herpesviruses, induce a lifelong latent infection in humans. In about 1% of the general population, HHV-6 DNA is covalently integrated into the subtelomeric region of cell chromosomes (ciHHV-6). Many active infections, corresponding to primary infections, reactivations, or exogenous reinfections, are asymptomatic. They also may cause serious diseases, particularly in immunocompromised individuals, including hematopoietic stem-cell transplant (HSCT) and solid-organ transplant recipients, and acquired immunodeficiency syndrome (AIDS) patients. This opportunistic pathogenic role is formally established for HHV-6 infection and less clear for HHV-7. It mainly concerns the central-nervous system, bone marrow, lungs, gastrointestinal tract, skin, and liver. As the best example, HHV-6 causes both exanthema subitum, a benign disease associated with primary infection, and severe encephalitis associated with virus reactivations in HSCT recipients. Diagnosis using serologic and direct antigen-detection methods currently exhibits limitations. The most prominent technique is the quantification of viral DNA in blood, other body fluids, and organs by means of real-time polymerase-chain reaction (PCR). The antiviral compounds ganciclovir, foscarnet, and cidofovir are effective against active infections, but there is currently no consensus regarding the indications of treatment or specifics of drug administration. Numerous questions about HHV-6A, HHV-6B, HHV-7 are still pending, concerning in particular clinical impact and therapeutic options in immunocompromised patients.
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Ongrádi J, Ablashi DV, Yoshikawa T, Stercz B, Ogata M. Roseolovirus-associated encephalitis in immunocompetent and immunocompromised individuals. J Neurovirol 2017; 23:1-19. [PMID: 27538995 PMCID: PMC5329081 DOI: 10.1007/s13365-016-0473-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 06/15/2016] [Accepted: 07/17/2016] [Indexed: 01/26/2023]
Abstract
The roseoloviruses, human herpesvirus (HHV)-6A, HHV-6B, and HHV-7, can cause severe encephalitis or encephalopathy. In immunocompetent children, primary HHV-6B infection is occasionally accompanied by diverse clinical forms of encephalitis. Roseolovirus coinfections with heterologous viruses and delayed primary HHV-7 infection in immunocompetent adults result in very severe neurological and generalized symptoms. Recovery from neurological sequelae is slow and sometimes incomplete. In immunocompromised patients with underlying hematological malignancies and transplantation, frequent single or simultaneous reactivation of roseoloviruses elicit severe, lethal organ dysfunctions, including damages in the limbic system, brain stem, and hippocampus. Most cases have been due to HHV-6B with HHV-6A accounting for 2-3%. The most severe manifestation of HHV-6B reactivation is post-transplantation limbic encephalitis. Seizures, cognitive problems, and abnormal EEG are common. Major risk factors for HHV-6B-associated encephalitis include unrelated cord blood cell transplantation and repeated hematopoietic stem cell transplantation. Rare genetic disorders, male gender, certain HLA constellation, and immune tolerance to replicating HHV-6 in persons carrying chromosomally integrated HHV-6 might also predispose an individual to roseolovirus-associated brain damage. At this time, little is known about the risk factors for HHV-7-associated encephalitis. Intrathecal glial cell destruction due to virus replication, overexpression of proinflammatory cytokines, and viral mimicry of chemokines all contribute to brain dysfunction. High virus load in the cerebrospinal fluid, hippocampal astrogliosis, and viral protein expression in HHV-6B-associated cases and multiple microscopic neuronal degeneration in HHV-7-associated cases are typical laboratory findings. Early empirical therapy with ganciclovir or foscarnet might save the life of a patient with roseolovirus-associated encephalitis.
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Affiliation(s)
- Joseph Ongrádi
- Institute of Medical Microbiology, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary.
| | - Dharam V Ablashi
- HHV-6 Foundation, 1482 East Valley Road, Santa Barbara, CA, 93101, USA
| | - Tetsushi Yoshikawa
- Department of Pediatrics, Fujita Health University School of Medicine, 1-98, Kotsukake-cho, Dengakugakolo, Toyoake, Aichi, 470-1192, Japan
| | - Balázs Stercz
- Institute of Medical Microbiology, Semmelweis University, Nagyvárad tér 4, Budapest, 1089, Hungary
| | - Masao Ogata
- Department of Medical Oncology and Hematology, Oita University Hospital, Hasama-machi, Yufu City, 879-5593, Japan
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Agut H, Bonnafous P, Gautheret-Dejean A. Laboratory and clinical aspects of human herpesvirus 6 infections. Clin Microbiol Rev 2015; 28:313-35. [PMID: 25762531 PMCID: PMC4402955 DOI: 10.1128/cmr.00122-14] [Citation(s) in RCA: 182] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Human herpesvirus 6 (HHV-6) is a widespread betaherpesvirus which is genetically related to human cytomegalovirus (HCMV) and now encompasses two different species: HHV-6A and HHV-6B. HHV-6 exhibits a wide cell tropism in vivo and, like other herpesviruses, induces a lifelong latent infection in humans. As a noticeable difference with respect to other human herpesviruses, genomic HHV-6 DNA is covalently integrated into the subtelomeric region of cell chromosomes (ciHHV-6) in about 1% of the general population. Although it is infrequent, this may be a confounding factor for the diagnosis of active viral infection. The diagnosis of HHV-6 infection is performed by both serologic and direct methods. The most prominent technique is the quantification of viral DNA in blood, other body fluids, and organs by means of real-time PCR. Many active HHV-6 infections, corresponding to primary infections, reactivations, or exogenous reinfections, are asymptomatic. However, the virus may be the cause of serious diseases, particularly in immunocompromised individuals. As emblematic examples of HHV-6 pathogenicity, exanthema subitum, a benign disease of infancy, is associated with primary infection, whereas further virus reactivations can induce severe encephalitis cases, particularly in hematopoietic stem cell transplant recipients. Generally speaking, the formal demonstration of the causative role of HHV-6 in many acute and chronic human diseases is difficult due to the ubiquitous nature of the virus, chronicity of infection, existence of two distinct species, and limitations of current investigational tools. The antiviral compounds ganciclovir, foscarnet, and cidofovir are effective against active HHV-6 infections, but the indications for treatment, as well as the conditions of drug administration, are not formally approved to date. There are still numerous pending questions about HHV-6 which should stimulate future research works on the pathophysiology, diagnosis, and therapy of this remarkable human virus.
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Affiliation(s)
- Henri Agut
- Sorbonne Universités, UPMC, CIMI-Paris UMRS CR7, PVI Team, Paris, France INSERM, CIMI-Paris U1135, PVI Team, Paris, France AP-HP, Hôpitaux Universitaires Pitié Salpêtrière-Charles Foix, Service de Virologie, Paris, France
| | - Pascale Bonnafous
- Sorbonne Universités, UPMC, CIMI-Paris UMRS CR7, PVI Team, Paris, France INSERM, CIMI-Paris U1135, PVI Team, Paris, France
| | - Agnès Gautheret-Dejean
- Sorbonne Universités, UPMC, CIMI-Paris UMRS CR7, PVI Team, Paris, France INSERM, CIMI-Paris U1135, PVI Team, Paris, France AP-HP, Hôpitaux Universitaires Pitié Salpêtrière-Charles Foix, Service de Virologie, Paris, France Université René Descartes, Faculté de Pharmacie, Laboratoire de Microbiologie UPRES EA 4065, Paris, France
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Affiliation(s)
- Joshua A Hill
- Division of Allergy and Infectious Diseases, University of Washington, Seattle, WA, USA.
| | - Nagagopal Venna
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
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Agut H. Deciphering the clinical impact of acute human herpesvirus 6 (HHV-6) infections. J Clin Virol 2011; 52:164-71. [DOI: 10.1016/j.jcv.2011.06.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 06/09/2011] [Accepted: 06/24/2011] [Indexed: 02/07/2023]
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Abstract
Human herpesvirus-6 (HHV-6) belongs to the herpesvirus family and is categorized into variant A and B (HHV-6A and HHV-6B). Primary HHV-6 infection in children and its related diseases are almost exclusively caused by HHV-6B and no disease caused by HHV-6A has been identified. The cellular receptor of HHV-6 has been shown to be a human CD46, and its viral ligand is an envelope glycoprotein complex, gH/gL/gQ1/gQ2 in HHV-6A. Furthermore, both cellular and viral lipid rafts play an important role in the HHV-6 entry process, suggesting that HHV-6 may enter its target cells through a lipid raft-associated mechanism.
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Affiliation(s)
- Huamin Tang
- Laboratoy of Virology, Division of Biomedical Research, National Institute of Biomedical Innovation, 7-6-8, Saito-Asagi, Ibaraki, Osaka 567-0085, Japan
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Razonable RR, Lautenschlager I. Impact of human herpes virus 6 in liver transplantation. World J Hepatol 2010; 2:345-53. [PMID: 21161019 PMCID: PMC2998978 DOI: 10.4254/wjh.v2.i9.345] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 07/14/2010] [Accepted: 07/21/2010] [Indexed: 02/06/2023] Open
Abstract
Human herpes virus 6 (HHV-6) infects > 95% of humans. Primary infection which occurs mostly during the first 2 years of life in the form of roseola infantum, non-specific febrile illness, or an asymptomatic illness, results in latency. Reactivation of latent HHV-6 is common after liver transplantation. Since the majority of human beings harbor the latent virus, HHV-6 infections after liver transplantation are most probably caused by endogenous reactivation or superinfection. In a minority of cases, primary HHV-6 infection may occur when an HHV-6-seronegative individual receives a liver allograft from an HHV-6-seropositive donor. The vast majority of HHV-6 infections after liver transplantation are asymptomatic. Only in a minority of cases, when HHV-6 causes a febrile illness associated with rash and myelosuppression, hepatitis, gastroenteritis, pneumonitis, and encephalitis after liver transplantation. In addition, HHV-6 has been implicated in a variety of indirect effects, such as allograft rejection and increased predisposition to and severity of other infections, including cytomegalovirus, hepatitis C virus, and opportunistic fungi. Because of the uncommon nature of the clinical illnesses directly attributed to HHV-6, there is currently no recommended HHV-6-specific approach prevention after liver transplantation. Asymptomatic HHV-6 infection does not require antiviral treatment, while treatment of established HHV-6 disease is treated with intravenous ganciclovir, foscarnet, or cidofovir and this should be complemented by a reduction in immunosuppression.
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Affiliation(s)
- Raymund R Razonable
- Raymund R Razonable, Division of Infectious Diseases, Department of Medicine, and the William J von Liebig Transplant Center, College of Medicine, Mayo Clinic, Rochester, MN 55905, United States
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Mancuso R, Hernis A, Cavarretta R, Caputo D, Calabrese E, Nemni R, Ferrante P, Delbue S, Clerici M. Detection of viral DNA sequences in the cerebrospinal fluid of patients with multiple sclerosis. J Med Virol 2010; 82:1051-7. [DOI: 10.1002/jmv.21764] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Shintaku M, Kaneda D, Tada K, Katano H, Sata T. Human herpes virus 6 encephalomyelitis after bone marrow transplantation: Report of an autopsy case. Neuropathology 2010; 30:50-5. [DOI: 10.1111/j.1440-1789.2009.01020.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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17
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Abstract
Human herpesvirus 6 (HHV-6) infections occur in > 95% of humans. Primary infection, which occurs in early childhood as an asymptomatic illness or manifested clinically as roseola infantum, leads to a state of subclinical viral persistence and latency. Reactivation of latent HHV-6 is common after liver transplantation, possibly induced and facilitated by allograft rejection and immunosuppressive therapy. Since the vast majority of humans harbor the virus in a latent state, HHV-6 infections after liver transplantation are believed to be mostly due to endogenous reactivation or superinfection (reactivation in the transplanted organ). In a minority of cases, however, primary HHV-6 infection may occur when an HHV-6 negative individual receives a liver allograft from an HHV-6 positive donor. The vast majority of documented HHV-6 infections after liver transplantation are asymptomatic. In a minority of cases, HHV-6 has been implicated as a cause of febrile illness with rash and myelosuppression, hepatitis, pneumonitis, and encephalitis after liver transplantation. In addition, HHV-6 has been associated with a variety of indirect effects such as allograft rejection, and increased predisposition and severity of other infections including cytomegalovirus (CMV), hepatitis C virus, and opportunistic fungi. Because of the uncommon nature of the clinical illnesses directly attributed to HHV-6, there is currently no recommended HHV-6-specific approach to prevention. However, ganciclovir and valganciclovir, which are primarily intended for the prevention of CMV disease, are also active against HHV-6 and may prevent its reactivation after transplantation. The treatment of established HHV-6 disease is usually with intravenous ganciclovir, cidofovir, or foscarnet, complemented by reduction in the degree of immunosuppression. This article reviews the current advances in the pathogenesis, clinical diagnosis, and therapeutic modalities against HHV6 in the setting of liver transplantation.
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Provenzale JM, vanLandingham KE, Lewis DV, Mukundan S, White LE. Extrahippocampal involvement in human herpesvirus 6 encephalitis depicted at MR imaging. Radiology 2008; 249:955-63. [PMID: 18849501 DOI: 10.1148/radiol.2492071917] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To test the hypothesis that patterns of signal intensity abnormality in human herpesvirus 6 (HHV6)-positive patients would allow distinction from patients who did not test positive for HHV6 encephalitis. MATERIALS AND METHODS This retrospective study was performed with institutional review board committee approval by using a waiver of informed consent. Sixteen immunocompromised patients (nine males, seven females; age range, 2-39 years) underwent magnetic resonance (MR) imaging and cerebrospinal fluid polymerase chain reaction (PCR) testing for HHV6 DNA on the basis of clinical findings suspicious for encephalitis. MR images acquired during acute illness were examined without knowing PCR results. RESULTS Nine patients were HHV6 positive. Seven showed signal intensity abnormalities, with prominent involvement of the hippocampus, and six showed additional involvement of the amygdala. Three HHV6-positive patients showed signal intensity abnormality in extrahippocampal divisions of the olfactory cortex and cortical and subcortical structures that maintain prominent connections with the hippocampal formation. Among the seven HHV6-negative patients, six had abnormalities in the hippocampus but only two showed extrahippocampal involvement, which was restricted to the amygdala. CONCLUSION Most patients with HHV6 encephalitis have signal intensity abnormalities in the hippocampal formation and amygdala and, contrary to prior reports, some also have involvement of limbic structures outside of the medial temporal lobe. The presence of MR signal intensity abnormality in the medial temporal lobe should raise the diagnosis of HHV6 encephalitis in immunosuppressed patients, especially when hyperintense lesions are seen in the insular region and inferior frontal lobe.
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Affiliation(s)
- James M Provenzale
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA.
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Akhyani N, Fotheringham J, Yao K, Rashti F, Jacobson S. Efficacy of antiviral compounds in human herpesvirus-6-infected glial cells. J Neurovirol 2006; 12:284-93. [PMID: 16966219 DOI: 10.1080/13550280600880772] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The beta-herpesvirus human herpesvirus-6 (HHV-6) is becoming increasingly recognized as an important pathogen in immunocompromised patients, particularly in post bone marrow transplant (BMT). Reactivation of latent HHV-6 resulting in encephalitis has been reported in BMT and stem cell transplant (SCT) patients. The development of HHV-6 encephalitis can be a fatal complication, the frequency of which is increasing likely due to improved diagnosis with quantitative polymerase chain reaction (PCR) of cerebrospinal fluid. There are currently no antiviral compounds approved for HHV-6, nor have any controlled clinical trials been conducted. The frequency and severity of HHV-6 encephalitis in both immunocompetent and immunocompromised patients necessitates studies on the usefulness of currently available anti-viral compounds. The authors compared the antiviral efficacy of four drugs currently used for cytomegalovirus (CMV) infection, a beta-herpesvirus sharing homology with HHV-6. In HHV-6A- and HHV-6B-infected T cells, acyclovir, ganciclovir, foscarnet, and cidofovir exhibited antiviral activity consistent with that published in other studies. In HHV-6-infected human astrocytes (U251), however, only foscarnet and cidofovir exhibited antiviral activity and this effect was restricted to infection with HHV-6 variant A. In pathological brain sections from patients with neurological disorders such as multiple sclerosis and epilepsy, HHV-6 has been localized to glial cells. Determination of antiviral activity in human glial fibrillary acidic protein (GFAP)-positive astrocytes of currently used antiviral compounds is essential for potential treatment of HHV-6 and neurological disorders. Our data highlight the necessity for further study of antiviral compound in HHV-6-infected glial cells as well as the development of more selective compounds for HHV-6.
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Affiliation(s)
- Nahid Akhyani
- Viral Immunology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA
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Astriti M, Zeller V, Boutolleau D, Gautheret-Dejean A, Allen G, Seilhean D, Agut H, Bricaire F, Katlama C, Bossi P. Fatal HHV-6 associated encephalitis in an HIV-1 infected patient treated with cidofovir. J Infect 2006; 52:237-42. [PMID: 16188320 DOI: 10.1016/j.jinf.2005.07.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2005] [Accepted: 07/23/2005] [Indexed: 11/24/2022]
Abstract
We describe the case of a patient infected with HIV and a concomitant HHV-6 encephalitis. The patient experienced virological failure following cidofovir treatment. RT-PCR was used both for early diagnosis and follow-up.
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Affiliation(s)
- Myrto Astriti
- Department of Infectious Diseases, Pitié-Salpêtrière Hospital, 47-83 Boulevard de l'Hôpital, 75651 Paris Cedex 13, France
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Riel-Romero RMS. Neurologic Manifestations of Human Herpesvirus-6 Infection. INFECTIOUS DISEASES IN CLINICAL PRACTICE 2005. [DOI: 10.1097/01.idc.0000152467.88222.40] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Debiasi RL, Tyler KL. Molecular methods for diagnosis of viral encephalitis. Clin Microbiol Rev 2005; 17:903-25, table of contents. [PMID: 15489354 PMCID: PMC523566 DOI: 10.1128/cmr.17.4.903-925.2004] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hundreds of viruses cause central nervous system (CNS) disease, including meningoencephalitis and postinfectious encephalomyelitis, in humans. The cerebrospinal fluid (CSF) is abnormal in >90% of cases; however, routine CSF studies only rarely lead to identification of a specific etiologic agent. Diagnosis of viral infections of the CNS has been revolutionized by the advent of new molecular diagnostic technologies to amplify viral nucleic acid from CSF, including PCR, nucleic acid sequence-based amplification, and branched-DNA assay. PCR is ideally suited for identifying fastidious organisms that may be difficult or impossible to culture and has been widely applied for detection of both DNA and RNA viruses in CSF. The technique can be performed rapidly and inexpensively and has become an integral component of diagnostic medical practice in the United States and other developed countries. In addition to its use for identification of etiologic agents of CNS disease in the clinical setting, PCR has also been used to quantitate viral load and monitor duration and adequacy of antiviral drug therapy. PCR has also been applied in the research setting to help discriminate active versus postinfectious immune-mediate disease, identify determinants of drug resistance, and investigate the etiology of neurologic disease of uncertain cause. This review discusses general principles of PCR and reverse transcription-PCR, including qualitative, quantitative, and multiplex techniques, with comment on issues of sensitivity, specificity, and positive and negative predictive values. The application of molecular diagnostic methods for diagnosis of specific infectious entities is reviewed in detail, including viruses for which PCR is of proven efficacy and is widely available, viruses for which PCR is less widely available or for which PCR has unproven sensitivity and specificity, and nonviral entities which can mimic viral CNS disease.
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Affiliation(s)
- Roberta L Debiasi
- Department of Pediatrics, Division of Infectious Diseases, University of Colorado Health Sciences Center, Box A036/B055, Denver, CO 80262, USA.
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De Bolle L, Naesens L, De Clercq E. Update on human herpesvirus 6 biology, clinical features, and therapy. Clin Microbiol Rev 2005; 18:217-45. [PMID: 15653828 PMCID: PMC544175 DOI: 10.1128/cmr.18.1.217-245.2005] [Citation(s) in RCA: 341] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Human herpesvirus 6 (HHV-6) is a betaherpesvirus that is closely related to human cytomegalovirus. It was discovered in 1986, and HHV-6 literature has expanded considerably in the past 10 years. We here present an up-to-date and complete overview of the recent developments concerning HHV-6 biological features, clinical associations, and therapeutic approaches. HHV-6 gene expression regulation and gene products have been systematically characterized, and the multiple interactions between HHV-6 and the host immune system have been explored. Moreover, the discovery of the cellular receptor for HHV-6, CD46, has shed a new light on HHV-6 cell tropism. Furthermore, the in vitro interactions between HHV-6 and other viruses, particularly human immunodeficiency virus, and their relevance for the in vivo situation are discussed, as well as the transactivating capacities of several HHV-6 proteins. The insight into the clinical spectrum of HHV-6 is still evolving and, apart from being recognized as a major pathogen in transplant recipients (as exemplified by the rising number of prospective clinical studies), its role in central nervous system disease has become increasingly apparent. Finally, we present an overview of therapeutic options for HHV-6 therapy (including modes of action and resistance mechanisms).
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Affiliation(s)
- Leen De Bolle
- Rega Institute for Medical Research, Minderbroedersstraat 10, B-3000 Leuven, Belgium
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Abstract
BACKGROUND Viral encephalitis occurs in epidemic settings or is sporadic. New encephalitis patterns reflect the roles that biologic reservoirs and vectors play in determining virus-human interactions. "New" viral encephalitis can also result from human host modifications that increase susceptibility to neuroinvasive viral infection. REVIEW SUMMARY Three human viruses, Nipah virus, Human Herpesvirus-6, and West Nile virus, present examples of how "new" viral encephalitides emerge in a specific geographic region or clinical setting. Nipah virus encephalitis emerged after the molecular evolution of a new zoonotic viral genus within the Paramyxovirinae family. Human herpesvirus-6 encephalitis has emerged in the immune suppressed human host harboring this ubiquitous but typically benign herpesvirus. West Nile virus encephalitis has emerged in the Western hemisphere after apparent abrupt translocation of this mosquito-borne virus to a distant geographic region with immunologically naive avian and human hosts. CONCLUSION While the clinical features of these viral encephalitides are somewhat distinct, they each emerged as the result of human-derived factors that altered the biologic dynamic between humans and their viral pathogens.
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Affiliation(s)
- Micheline McCarthy
- Department of Neurology, University of Miami School of Medicine, Miami, Florida 33125, USA.
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Gravel A, Tomoiu A, Cloutier N, Gosselin J, Flamand L. Characterization of the immediate-early 2 protein of human herpesvirus 6, a promiscuous transcriptional activator. Virology 2003; 308:340-53. [PMID: 12706083 DOI: 10.1016/s0042-6822(03)00007-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
In the present work we report the cloning of a full-length cDNA encoding the immediate-early (IE) 2 protein from human herpesvirus 6 (HHV-6) variant A (GS strain). The transcript is 4690 nucleotides long and composed of 5 exons. Translation initiation occurs within the third exon and proceeds to the end of U86. Kinetic studies indicate that the 5.5-kb IE2 mRNA is expressed under IE condition, within 2-4 h of infection. IE2 transcripts from both variants A and B are expressed under similar kinetics with IE2 transcripts accumulating up to 96 h postinfection. Although several large transcripts (>5.5 kb) hybridized with the IE2 probe, suggesting multiple transcription initiation sites, a single form of the IE2 protein, in excess of 200 kDa, was detected by Western blot. Within cells, the IE2 protein was detected (8-48 h) as intranuclear granules while at later time points (72-120 h), the IE2 protein coalesced into a few large immunoreactive patches. Transfection of cells with an IE2 expression vector (pBK-IE2A) failed to reproduce the patch-like distribution, suggesting that other viral proteins are necessary for this process to occur. Last, IE2 was found to behave as a promiscuous transcriptional activator. Cotransfection experiments in T cells indicate that IE2 can induce the transcription of a complex promoter, such as the HIV-LTR, as well as simpler promoters, whose expression is driven by a unique set of responsive elements (CRE, NFAT, NF-kB). Moreover, minimal promoters having a single TATA box or no defined eukaryotic regulatory elements were significantly activated by IE2, suggesting that IE2 is likely to play an important role in initiating the expression of several HHV-6 genes. In all, the work presented represents the first report on the successful cloning, expression, and functional characterization of the major regulatory IE2 gene/protein of HHV-6.
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Affiliation(s)
- Annie Gravel
- Laboratory of Virology, Rheumatology and Immunology Research Center, CHUL Research Center and Faculty of Medicine, Laval University, Québec, Canada
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Cinque P, Bossolasco S, Lundkvist A. Molecular analysis of cerebrospinal fluid in viral diseases of the central nervous system. J Clin Virol 2003; 26:1-28. [PMID: 12589831 PMCID: PMC7128469 DOI: 10.1016/s1386-6532(02)00173-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The use of nucleic acid (NA) amplification techniques has transformed the diagnosis of viral infections of the central nervous system (CNS). Because of their enhanced sensitivity, these methods enable detection of even low amounts of viral genomes in cerebrospinal fluid. Following more than 10 years of experience, the polymerase chain reaction or other NA-based amplification techniques are nowadays performed in most diagnostic laboratories and have become the test of choice for the diagnosis of several viral CNS infections, such as herpes encephalitis, enterovirus meningitis and other viral infections occurring in human immunodeficiency virus-infected persons. Furthermore, they have been useful to establish a viral etiology in neurological syndromes of dubious origin and to recognise unusual or poorly characterised CNS diseases. Quantitative methods have provided a valuable additional tool for clinical management of these diseases, whereas post-amplification techniques have enabled precise genome characterisation. Current efforts are aiming at further improvement of the diagnostic efficiency of molecular techniques, their speed and standardisation, and to reduce the costs. The most relevant NA amplification strategies and clinical applications of to date will be the object of this review.
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Affiliation(s)
- Paola Cinque
- Clinic of Infectious Diseases, San Raffaele Hospital, Via Stamira d'Ancona, 20, 20127, Milan, Italy.
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Caselli E, Boni M, Bracci A, Rotola A, Cermelli C, Castellazzi M, Di Luca D, Cassai E. Detection of antibodies directed against human herpesvirus 6 U94/REP in sera of patients affected by multiple sclerosis. J Clin Microbiol 2002; 40:4131-7. [PMID: 12409386 PMCID: PMC139661 DOI: 10.1128/jcm.40.11.4131-4137.2002] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The association between human herpesvirus 6 (HHV-6) and multiple sclerosis (MS) is controversial. In fact, it is difficult to establish a causative role of HHV-6, due to the high prevalence of latently infected individuals in the healthy population. Therefore, the presence of virus sequences in tissue biopsy does not support a viral role, and serological assays do not show significant differences between MS patients and control populations. The only viral gene expressed during latency is U94/rep. Therefore, we have developed a serological assay for the detection of antibodies specifically directed against U94/REP protein. Different populations were analyzed by enzyme-linked immunosorbent assay, including healthy controls, MS patients, and subjects with diseases unrelated to HHV-6 infection, including other neurological diseases. The results show statistically significant differences (P > 0.01) between MS patients and control groups, both in antibody prevalence (87 and 43.9%, respectively) and in geometric mean titer (1:515 and 1:190, respectively). The detection of antibodies specific for HHV-6 U94/REP shows that the immune system is exposed to this antigen during natural infection. The higher prevalence and higher titers of antibodies to U94/REP suggest that MS patients and control groups might experience different exposures to HHV-6.
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Affiliation(s)
- Elisabetta Caselli
- Section of Microbiology, Department of Experimental and Diagnostic Medicine. Section of Neurology, Department of Medical Surgical, Communication and Behavioral Sciences, University of Ferrara, Ferrara, Italy
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Mori Y, Seya T, Huang HL, Akkapaiboon P, Dhepakson P, Yamanishi K. Human herpesvirus 6 variant A but not variant B induces fusion from without in a variety of human cells through a human herpesvirus 6 entry receptor, CD46. J Virol 2002; 76:6750-61. [PMID: 12050388 PMCID: PMC136280 DOI: 10.1128/jvi.76.13.6750-6761.2002] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human herpesvirus 6 (HHV-6) is a lymphotropic betaherpesvirus that productively infects T cells and monocytes. HHV-6 isolates can be differentiated into two groups, variants A and B (HHV-6A and HHV-6B). Here, we show a functional difference between HHV-6A and -6B in that HHV-6A induced syncytium formation of diverse human cells but HHV-6B did not. The syncytium formation induced by HHV-6A was observed 2 h after infection; moreover, it was found in the presence of cycloheximide, indicating that HHV-6A induced fusion from without (FFWO) in the target cells. Furthermore, the fusion event was dependent on the expression of the HHV-6 entry receptor, CD46, on the target cell membrane. In addition, we determined that short consensus repeat 2 (SCR2), -3, and -4 of the CD46 ectodomain were essential for the formation of the virus-induced syncytia. Monoclonal antibodies against glycoproteins B and H of HHV-6A inhibited the fusion event, indicating that the syncytium formation induced by HHV-6A required glycoproteins H and B. These findings suggest that FFWO, which HHV-6A induced in a variety of cell lines, may play an important role in the pathogenesis of HHV-6A, not only in lymphocytes but also in various tissues, because CD46 is expressed ubiquitously in human tissues.
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Affiliation(s)
- Yasuko Mori
- Department of Microbiology, Osaka University Medical School, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan.
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Leach CT, Pollock BH, McClain KL, Parmley RT, Murphy SB, Jenson HB. Human herpesvirus 6 and cytomegalovirus infections in children with human immunodeficiency virus infection and cancer. Pediatr Infect Dis J 2002; 21:125-32. [PMID: 11840079 DOI: 10.1097/00006454-200202000-00008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIM Measure the prevalence of human herpesvirus 6 (HHV-6) and cytomegalovirus (CMV) infections in children and adolescents with HIV infection and malignancy. METHODS Semiquantitative polymerase chain reaction and serology were used to test for HHV-6 and CMV infections in 31 cases (HIV-infected children with cancer), 56 HIV controls (HIV-infected children without cancer) and 30 cancer controls (HIV-uninfected children with cancer). RESULTS In cases, HIV controls and cancer controls, HHV-6 DNA was detected in 29, 39 and 34%, respectively, and CMV DNA was detected in 13, 4 and 7%, respectively. Four cases (13%) and no HIV controls or cancer controls harbored HHV-6 subtype A (P = 0.014). In cases, HIV controls and cancer controls, the prevalence of HHV-6 antibodies was 58, 68 and 93%, respectively, and the prevalence of CMV antibodies was 71, 48 and 70%, respectively. HHV-6 seroprevalence was lower in cases than in cancer controls (P = 0.002), even with adjustments for age and CD4 concentrations; however, HHV-6 infection rates (presence of HHV-6 DNA and/or HHV-6 antibodies) were similar in all groups. Stratification showed that CMV infection was more common in younger patients (ages < 8 years) without severe immune suppression (CD4 concentration >200 cells/microl) than in HIV controls (odds ration, 10.343; 95% confidence interval, 1.65, 121.57). Geometric mean titers of serum anti-CMV antibodies, but not anti-HHV-6 antibodies, were higher in cases (1:71) than in HIV controls (1:33) (P = 0.005). CONCLUSIONS HHV-6 and CMV infections were common among children with HIV infection and cancer. CMV seropositivity also was associated with cancer in younger HIV-infected patients who did not have severe immune suppression. HHV-6A was detected only in HIV-infected children with cancer.
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Affiliation(s)
- Charles T Leach
- Department of Pediatrics, Division of Infectious Diseases, The University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
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30
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Caserta MT, Mock DJ, Dewhurst S. Human herpesvirus 6. Clin Infect Dis 2001; 33:829-33. [PMID: 11512088 DOI: 10.1086/322691] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2001] [Revised: 03/07/2001] [Indexed: 11/03/2022] Open
Abstract
The development of techniques for the culture of lymphoid cells and the isolation of viruses that infect these cells led to the discovery of human herpesvirus (HHV) 6 in 1986. At the time, HHV-6 was the first new human herpesvirus to be discovered in roughly a quarter of a century, and its isolation marked the beginning of an era of discovery in herpesvirology, with the identification of HHV-7 and HHV-8 (Kaposi's sarcoma-associated herpesvirus) during the following decade. Like most human herpesviruses, HHV-6 is ubiquitous and capable of establishing a lifelong, latent infection of its host. HHV-6 is particularly efficient at infecting infants and young children, and primary infection with the virus is associated with roseola infantum (exanthem subitum) and, most commonly, an undifferentiated febrile illness. Viral reactivation in the immunocompromised host has been linked to a variety of diseases, including encephalitis, and HHV-6 has been tentatively associated with multiple sclerosis. This article discusses the major properties of HHV-6, its association with human disease, and the pathobiological significance of viral reactivation.
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Affiliation(s)
- M T Caserta
- Department of Pediatrics, University of Rochester Medical Center, Rochester, NY 14642, USA
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Daibata M, Hatakeyama N, Kamioka M, Nemoto Y, Hiroi M, Miyoshi I, Taguchi H. Detection of human herpesvirus 6 and JC virus in progressive multifocal leukoencephalopathy complicating follicular lymphoma. Am J Hematol 2001; 67:200-5. [PMID: 11391720 DOI: 10.1002/ajh.1108] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Progressive multifocal leukoencephalopathy (PML), a demyelinating infectious disease caused by JC virus (JCV), occurs almost exclusively in immunocompromised patients usually with malignant diseases. We report here a Japanese female with follicular lymphoma who subsequently developed PML. In addition to JCV, human herpesvirus 6 (HHV-6) was detected in the affected brain lesions of the patient by polymerase chain reaction and by in situ hybridization. HHV-6, recognized as a neurotropic virus, is known to be reactivated during immunosuppression and can cause fatal complications such as encephalitis/encephalopathy. It is likely that impaired immunity associated with lymphoma and the additional immunosuppression following cytopenia-inducing chemotherapies predisposed the patient to reactivated HHV-6 infection. Although it remains to be clarified whether HHV-6 plays an important role as a co-agent with JCV in causing demyelination of the brain, our observation alerts physicians to the possible association of HHV-6 with the pathogenesis of PML.
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MESH Headings
- Adult
- Antineoplastic Combined Chemotherapy Protocols/adverse effects
- Antineoplastic Combined Chemotherapy Protocols/therapeutic use
- Bleomycin/administration & dosage
- Bleomycin/adverse effects
- Brain/pathology
- Brain/virology
- Cyclophosphamide/administration & dosage
- Cyclophosphamide/adverse effects
- DNA, Viral/isolation & purification
- Doxorubicin/administration & dosage
- Doxorubicin/adverse effects
- Etoposide/administration & dosage
- Etoposide/adverse effects
- Fatal Outcome
- Female
- Herpesviridae Infections/complications
- Herpesviridae Infections/virology
- Herpesvirus 6, Human/isolation & purification
- Herpesvirus 6, Human/pathogenicity
- Herpesvirus 6, Human/physiology
- Humans
- Immunity, Cellular/drug effects
- Immunocompromised Host
- JC Virus/isolation & purification
- JC Virus/pathogenicity
- JC Virus/physiology
- Leukoencephalopathy, Progressive Multifocal/etiology
- Leukoencephalopathy, Progressive Multifocal/pathology
- Leukoencephalopathy, Progressive Multifocal/virology
- Lymphoma, Follicular/complications
- Lymphoma, Follicular/drug therapy
- Magnetic Resonance Imaging
- Mitoxantrone/administration & dosage
- Mitoxantrone/adverse effects
- Nitrosourea Compounds/administration & dosage
- Nitrosourea Compounds/adverse effects
- Papillomavirus Infections/complications
- Papillomavirus Infections/virology
- Piperazines/administration & dosage
- Piperazines/adverse effects
- Polymerase Chain Reaction
- Prednisolone/administration & dosage
- Prednisolone/adverse effects
- Recurrence
- Salvage Therapy
- Vincristine/administration & dosage
- Vincristine/adverse effects
- Vindesine/administration & dosage
- Vindesine/adverse effects
- Virus Activation
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Affiliation(s)
- M Daibata
- Department of Medicine, Kochi Medical School, Kochi, Japan.
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32
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Abstract
Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system whose cause is still unknown. Many findings suggest an infectious etiology or, at least, that infectious agents in association with host genetic factors may play a role in the pathogenesis of this disease. Accumulating data, including animal models, human models of virus induced demyelination, epidemiologic, and laboratory findings, demonstrate that viruses and host genetic factors can interact to cause immune-mediated demyelination. While many viruses have been postulated as a possible cause of MS, to date, no "MS virus" has been definitively shown to be associated with this disease. Alternatively, ubiquitous viruses are being considered as the environmental "triggers" that have been postulated to be involved in the MS disease process. We will focus on recent studies with human herpesvirus 6 and MS as how a common virus may be associated with this disorder in a subset of infected individuals.
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Affiliation(s)
- C Cermelli
- Viral Immunology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892, USA
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33
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Khare MD. Human herpesvirus 6: its impact and influence on infectious diseases and their management. Expert Opin Pharmacother 2001; 2:213-21. [PMID: 11336581 DOI: 10.1517/14656566.2.2.213] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Human herpesvirus (HHV)-6 was discovered 15 years ago and was then grouped as a member of the family human herpesviridae. Its first clinical manifestation was identified 2 years later as the agent responsible for exanthem subitum. With the advent of newer molecular techniques, its diagnosis is easier and prospective studies have shown that it is the most common pathogen responsible for febrile illness in infants. In some infants, it is associated with febrile convulsions. Two subtypes, A and B, have been identified, B subtype commonly being responsible for primary infection in infants. Primary infection in healthy adults is rare. Most of the clinical manifestations are mild, self-limiting and rarely fatal. Reactivation of HHV-6 is frequently found in bone marrow as well as solid organ transplant recipients. HHV-6 has been shown to be an independent risk factor responsible for recurrence of cytomegalovirus infection, especially in solid organ transplants. In bone marrow transplant recipients, HHV-6 has been associated with various manifestations like marrow suppression and graft versus host disease, although most infections present as usually mild febrile illness with or without rash. It has been reported to cause encephalitis in transplant recipients. Although HHV-6 has been shown to be responsible for upregulation of HIV in vitro studies, its exact role in AIDS is yet to be defined. In addition to its neurotropic manifestation of febrile convulsion in infancy, it has been found in plaques in the brain of multiple sclerosis and progressive multifocal leukoencephalopathy. Further studies are needed before its role in the pathogenesis of these neurological illnesses can be established. Its lymphotropic feature was responsible for its discovery and now it has only been detected in some lesions of primary ocular mucosa associated lymphoid tissue lymphoma. As HHV-6 is found to be responsible for more and more illnesses, especially causing serious illnesses in the immunocompromised, it is becoming necessary to find effective treatment. Some agents, like cidofovir and phosphonoformic acid, are effective in in vitro studies and some have shown effectiveness in a clinical setting. Further studies are needed to identify its role in the pathogenesis of various neurological and malignant lesions and AIDS. Various treatment regimens should be tested in clinical scenario and especially in immunocompromised transplant recipients.
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Affiliation(s)
- M D Khare
- St. George's Hospital Medical School, Cranmer Terrace, London SW17 0RE, UK.
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34
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Abstract
Although it has been recognised that human herpesvirus 7 (HHV-7) establishes latent infection in CD4+ T lymphocytes and productive infection in salivary glands, recent data suggest that its in vivo tropism may be more widespread. In this study, the prevalence and distribution of HHV-7 in brain tissues of 30 consecutive post-mortems were examined by nested polymerase chain reaction. For each post-mortem, 10 fresh autopsy tissue samples were collected respectively from the cerebellum, frontal, temporal, parietal, and occipital lobes of both cerebral hemispheres. These patients were aged from 20-95 years (mean = 61.4, SD = 20.2) with a male:female ratio of 2:1. Three patients died of intracranial haemorrhage, the others died of causes unrelated to the central nervous system. Overall, 5% (15/300) of the brain tissue samples were positive for HHV-7 DNA. The positive rates with respect to anatomical positions were similar (0-3/30). When analysed by patient, 36.7% (11/30) were HHV-7 DNA positive. The viral DNA-positive and -negative groups did not show a significant difference in gender or age distribution. The majority (81.8%) of viral DNA-positive patients had HHV-7 DNA detected at only one anatomical position; only two patients had viral DNA detected simultaneously at three anatomical sites. These results suggest that HHV-7 persists in brain tissues of a substantial proportion of the adult population, and in most individuals, its distribution is probably confined to one site rather than pervasive. Further studies to elucidate the role of this ubiquitous virus in neuropathology are warranted.
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Affiliation(s)
- P K Chan
- Department of Microbiology, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories.
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35
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Knox KK, Brewer JH, Henry JM, Harrington DJ, Carrigan DR. Human herpesvirus 6 and multiple sclerosis: systemic active infections in patients with early disease. Clin Infect Dis 2000; 31:894-903. [PMID: 11049767 DOI: 10.1086/318141] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/1999] [Revised: 02/23/2000] [Indexed: 11/03/2022] Open
Abstract
By means of immunohistochemical staining, cells actively infected with human herpesvirus 6 (HHV-6) were found in central nervous system tissues from 8 (73%) of 11 patients with definite multiple sclerosis (MS). Interestingly, 17 (90%) of 19 tissue sections showing active demyelination were positive for HHV-6-infected cells compared with only 3 (13%) of 23 tissue sections free of active disease (P<.0001). Central nervous system tissues from 2 of 28 normal persons and patients with other inflammatory demyelinative diseases were positive for HHV-6-infected cells (P<.0001), and the 2 positive cases were diagnosed as having HHV-6 leukoencephalitis. By use of a rapid culture assay, blood samples from 22 (54%) of 41 patients with definite MS were found to contain active HHV-6 infections, compared with 0 of 61 normal controls (P<.0001). No significant difference was found between HHV-6 viremia-positive and HHV-6 viremia-negative MS patients with respect to type of disease (relapsing/remitting or progressive). In contrast, patients with active HHV-6 viremia were significantly younger and had shorter durations of disease than did HHV-6 viremia-negative patients.
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Affiliation(s)
- K K Knox
- Institute for Viral Pathogenesis, Milwaukee, WI 53226, USA.
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36
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Abstract
Human herpesvirus-6 (HHV-6) and -7 (HHV-7) infections typically are silent or manifested as mild febrile illnesses including classic roseola. In addition, case reports and epidemiologic data support the rare occurrence of HHV-6 encephalitis in immunocompromised as well as immunocompetent subjects. Although many other diseases have been putatively associated with HHV-6 or HHV-7, these associations are not well documented due to small numbers, use of tests incapable of distinguishing latent from replicating virus, potential virus cross-reactivity, or contradictory results. Further careful studies are needed to confirm these disease associations. Laboratory tests for diagnosing active HHV-6 and HHV-7 infections include virus culture, antigen detection, and polymerase chain reaction of cell-free biologic fluid. Although HHV-6 and HHV-7 are inhibited by several antiviral drugs in the laboratory, including ganciclovir and foscarnet, no clinical trials have assessed their benefit. Nevertheless, treatment may be considered for patients with serious HHV-6- or HHV-7-associated disease confirmed with accurate virologic tests.
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Affiliation(s)
- C T Leach
- Department of Pediatrics, University of Texas Health Science Center at San Antonio 78229-3900, USA
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37
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Baillargeon J, Piper J, Leach CT. Epidemiology of human herpesvirus 6 (HHV-6) infection in pregnant and nonpregnant women. J Clin Virol 2000; 16:149-57. [PMID: 10738135 DOI: 10.1016/s1386-6532(99)00086-4] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Human herpesvirus 6 (HHV-6) is a ubiquitous virus primarily associated with benign conditions such as febrile syndromes and exanthem subitum (roseola infantum). Sexual, horizontal, and vertical transmission have been suggested. Little information is available regarding HHV-6 infection in women of reproductive age. OBJECTIVE Describe epidemiology of HHV-6 infection in pregnant and nonpregnant women. STUDY DESIGN The study sample consisted of 569 women, age 18-45, who attended a university family planning clinic (nonpregnant, n=224) and two obstetrics clinics (pregnant [first trimester], n=345) in San Antonio, TX between October 1995 and May 1998. Blood and a vaginal swab, as well as sociodemographic information, were collected from each participant. Plasma was tested for HHV-6 IgG antibodies using a standard immunofluorescence assay (IFA). Lysed material from vaginal swabs was tested for HHV-6 DNA by polymerase chain reaction (PCR). Products were screened by enzyme-linked immunosorbent assay and positive tests were confirmed by repeat PCR followed by Southern analysis. PCR-positive samples were subtyped using an established method. RESULTS All subjects were HHV-6 antibody positive. Geometric mean titers of HHV-6 antibodies were significantly higher among nonpregnant versus pregnant women. Moreover, a higher proportion of nonpregnant versus pregnant women had antibody titers >/=160 and >/=320. This association persisted even after adjusting for a number of sociodemographic and clinical factors. Low rates of HHV-6 shedding in the genital tract were observed for both groups (pregnant, 7/297 [2.0%]; nonpregnant, 8/214 [3.7%]). Of 14 samples subtyped, four (29%) were subtype A. CONCLUSION The present study showed that 100% of the study sample was infected with HHV-6. Higher HHV-6 antibody titers, however, were noted in nonpregnant women. Both groups shed virus at low rates in the genital tract. HHV-6 subtype A was identified more commonly than previously reported. Further longitudinal studies are required to assess the consequences of maternal HHV-6 infection.
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Affiliation(s)
- J Baillargeon
- Departments of Pediatrics, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, USA
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38
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Suga S, Suzuki K, Ihira M, Yoshikawa T, Kajita Y, Ozaki T, Iida K, Saito Y, Asano Y. Clinical characteristics of febrile convulsions during primary HHV-6 infection. Arch Dis Child 2000; 82:62-6. [PMID: 10630916 PMCID: PMC1718177 DOI: 10.1136/adc.82.1.62] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE To clarify clinical characteristics of children with febrile convulsions during primary human herpesvirus 6 (HHV-6) infection. SUBJECTS AND METHODS The clinical characteristics of first febrile convulsion were compared between those with and without primary HHV-6 infection in 105 children. HHV-6 infection was verified by culture or acute/convalescent anti-HHV-6 antibody titres. RESULTS Primary infection with HHV-6 was seen in 21 of 105 patients with febrile convulsions (3 upper respiratory infection, 1 lower respiratory infection, and 17 exanthem subitum). 13 of 23 patients < 1 year, 19 of 79 patients with first febrile convulsion, and 2 of 15 with second convulsion were infected with HHV-6. The median age of patients with first febrile convulsion and HHV-6 was significantly lower than those without infection. The frequency of clustering seizures, long lasting seizures, partial seizures, and postictal paralysis was significantly higher among those with primary HHV-6 infection than among those without. The frequency of atypical seizures in 19 patients with first febrile convulsion associated with primary infection was significantly higher than in 60 patients without primary infection. The frequency in infants younger than 1 year of age was also significantly higher than that in 10 age matched infants without primary infection. CONCLUSIONS These findings suggest that primary infection with HHV-6 is frequently associated with febrile convulsions in infants and young children and that it often results in the development of a more severe form of convulsions, such as partial seizures, prolonged seizures, and repeated seizures, and might be a risk factor for subsequent development of epilepsy.
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Affiliation(s)
- S Suga
- Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi 470-1192, Japan
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39
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Santoro F, Kennedy PE, Locatelli G, Malnati MS, Berger EA, Lusso P. CD46 is a cellular receptor for human herpesvirus 6. Cell 1999; 99:817-27. [PMID: 10619434 DOI: 10.1016/s0092-8674(00)81678-5] [Citation(s) in RCA: 368] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Human herpesvirus 6 (HHV-6) is the etiologic agent of exanthema subitum, causes opportunistic infections in immunocompromised patients, and has been implicated in multiple sclerosis and in the progression of AIDS. Here, we show that the two major HHV-6 subgroups (A and B) use human CD46 as a cellular receptor. Downregulation of surface CD46 was documented during the course of HHV-6 infection. Both acute infection and cell fusion mediated by HHV-6 were specifically inhibited by a monoclonal antibody to CD46; fusion was also blocked by soluble CD46. Nonhuman cells that were resistant to HHV-6 fusion and entry became susceptible upon expression of recombinant human CD46. The use of a ubiquitous immunoregulatory receptor opens novel perspectives for understanding the tropism and pathogenicity of HHV-6.
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MESH Headings
- Antibodies, Monoclonal/metabolism
- Antigens, CD/immunology
- Antigens, CD/metabolism
- Cell Fusion/genetics
- Cell Fusion/physiology
- Cells, Cultured
- Herpesviridae Infections/metabolism
- Herpesviridae Infections/virology
- Herpesvirus 6, Human/metabolism
- Herpesvirus 6, Human/pathogenicity
- Humans
- Leukocytes, Mononuclear/cytology
- Leukocytes, Mononuclear/metabolism
- Leukocytes, Mononuclear/virology
- Membrane Cofactor Protein
- Membrane Glycoproteins/immunology
- Membrane Glycoproteins/metabolism
- Receptors, Virus/immunology
- Receptors, Virus/metabolism
- Recombinant Proteins/metabolism
- Transfection
- Transgenes/genetics
- Transgenes/physiology
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Affiliation(s)
- F Santoro
- Unit of Human Virology, DIBIT, San Raffaele Scientific Institute, Milano, Italy
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40
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Abstract
The three novel human herpesviruses (HHV) 6, 7, and 8 are predominantly, but not exclusively, lymphotropic. In an attempt to elucidate their neurotropism in vivo, viral DNA sequences present in fresh autopsy cortical brain tissues obtained from 84 consecutive Chinese subjects (mean age, 66.9 years; range, 21-98 years) were detected by a nested polymerase chain reaction. These patients were apparently immunocompetent and free of clinical signs of viral diseases. HHV-6 DNA was detected in 36 of 84 (42.9%) patients, and the DNA-positive and -negative groups did not show a significant difference in age or sex distribution. Of the 36 HHV-6 DNA-positive cases, 9 (25%) were variant A and 27 (75%) were variant B. In view of the lower prevalence of variant A than variant B in the adult population, the two variants may share a comparable neuroinvasive potential. HHV-7 and HHV-8 DNA were detected respectively in three and two patients. The low positive rates of HHV-7 and HHV-8 may represent a relatively lower neuroinvasive potential of the viruses. Alternatively, the localization of HHV-7 and HHV-8 may be more restricted and the sampled cortical tissues may not represent the most abundant site of persistence in the nervous system. The results provide molecular evidence of the presence of the three newly identified herpesviruses in brain tissue. The pathogenic role for HHV-7 and HHV-8, as with HHV-6, in neurological diseases should not be overlooked.
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Affiliation(s)
- P K Chan
- Department of Microbiology, Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong, China.
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41
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French C, Menegazzi P, Nicholson L, Macaulay H, DiLuca D, Gompels UA. Novel, nonconsensus cellular splicing regulates expression of a gene encoding a chemokine-like protein that shows high variation and is specific for human herpesvirus 6. Virology 1999; 262:139-51. [PMID: 10489348 DOI: 10.1006/viro.1999.9875] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
There are few genes that are specific and diagnostic for human herpesvirus-6. U83 and U22 are two of them. U22 is unique, whereas U83 encodes distant similarity with some cellular chemokines. Reverse transcription-polymerase chain reaction, cDNA cloning, and sequence analyses show polyadenylated RNA transcripts corresponding to minor full-length and abundant spliced forms of U83 in human herpesvirus 6-infected cells. The splice donor and acceptor sites do not fit consensus sequences for either major GT-AG or minor AT-AC introns. However, the spliced form can also be detected in a U83 transfected cell line; thus the novel sites are used by cellular mechanisms. This intron may represent a new minor CT-AC splicing class. The novel splicing regulates gene expression by introducing a central stop codon that abrogates production of the chemokine-like molecule, resulting in an encoded truncated peptide. The use of metabolic inhibitors and an infection time course showed expression of the two RNA transcripts with immediate early kinetics. However, the full-length product accumulated later, dependent on virus DNA replication, similar to U22. Sequence analyses of 16 strains showed high variation (13%) in U83, with conservation of the novel splice sites. Representative strain variants had similar kinetics of expression and spliced products.
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Affiliation(s)
- C French
- London School of Hygiene and Tropical Medicine, University of London, London, WC1E 7HT, United Kingdom
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42
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Human Herpesvirus-6 and Sudden Death in Infancy: Report of a Case and Review of the Literature. J Forensic Sci 1999. [DOI: 10.1520/jfs14481j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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43
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Abstract
Infections with human herpesvirus 6 (HHV-6), a beta-herpesvirus of which two variant groups (A and B) are recognized, is very common, approaching 100% in seroprevalence. Primary infection with HHV-6B causes roseola infantum or exanthem subitum, a common childhood disease that resolves spontaneously. After primary infection, the virus replicates in the salivary glands and is shed in saliva, the recognized route of transmission for variant B strains; it remains latent in lymphocytes and monocytes and persists at low levels in cells and tissues. Not usually associated with disease in the immunocompetent, HHV-6 infection is a major cause of opportunistic viral infections in the immunosuppressed, typically AIDS patients and transplant recipients, in whom HHV-6 infection/reactivation may culminate in rejection of transplanted organs and death. Other opportunistic viruses, human cytomegalovirus and HHV-7, also infect or reactivate in persons at risk. Another disease whose pathogenesis may be correlated with HHV-6 is multiple sclerosis. Data in favor of and against the correlation are discussed.
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44
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Caserta MT, Hall CB. A practitioner's guide to human herpesvirus-6 (HHV-6) and human herpesvirus-7 (HHV-7). AIDS Patient Care STDS 1998; 12:833-42. [PMID: 11362039 DOI: 10.1089/apc.1998.12.833] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Human herpesvirus-6 (HHV-6) and HHV-7 are newly recognized ubiquitous human viruses first discovered in patients with AIDS or lymphoproliferative disorders. Much more information is available about the clinical characteristics of infection with HHV-6 than HHV-7. Primary infection with HHV-6 occurs in early childhood and is most commonly manifested as an undifferentiated highly febrile illness, with seizures noted to be the most common complication. A subset of children develop the classic manifestations of roseola infantum or exanthem subitum. Other neurologic diseases in adults such as encephalitis and multiple sclerosis also have been linked to HHV-6; however, the role of HHV-6 in these clinical entities has not been fully elucidated. Although HHV-6 and HIV are both tropic for CD4+ lymphocytes and interact in vitro, there is no evidence at present that HHV-6 plays a role in HIV disease. HHV-7 is similar to HHV-6 in genetic organization and structure. Little is known of the clinical characteristics of infection with HHV-7 or its ability to cause disease in children or reactivation in adults.
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Affiliation(s)
- M T Caserta
- Department of Pediatrics, University of Rochester School of Medicine and Dentistry, New York, USA
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45
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Abstract
The neuroradiologic findings of the brain lesions in eight infants with exanthema subitum were normal in three, suspected vascular lesions in two, and symmetric thalamic lesions with or without diffuse brain edema in the other three. In addition, diffuse brain edema or focal cerebral lesions were observed in 13 previously reported Japanese infants. These findings suggest that the pathogeneses of the brain lesions related to exanthema subitum are variable.
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Affiliation(s)
- S Kimura
- Department of Pediatrics, Urafune Hospital of Yokohama City University School of Medicine, Yokohama, Kanagawa, Japan
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46
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Wagner M, Müller-Berghaus J, Schroeder R, Sollberg S, Luka J, Leyssens N, Schneider B, Krueger GR. Human herpesvirus-6 (HHV-6)-associated necrotizing encephalitis in Griscelli's syndrome. J Med Virol 1997; 53:306-12. [PMID: 9365900 DOI: 10.1002/(sici)1096-9071(199711)53:3<306::aid-jmv21>3.0.co;2-d] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We report a male caucasian German pediatric patient of no Arab or Mediterranean ancestry with virus associated CNS lesions in Griscelli's syndrome (GS; McKusick No. 214450). The boy presented with recurrent infections, and meningitis with subsequent progressive signs of increased intracranial pressure leading to death at 32 weeks of age. At autopsy, various sites of the CNS revealed necroses in gray and white matter. CNS histology revealed numerous and massive predominantly perivascular CD8 positive lymphohistiocytic infiltrates. These findings were associated strictly with the presence of human herpesvirus-6 (HHV-6) genome or the HHV-6 specific late antigen H-AR 3, found in neurons, oligodendrocytes, and astrocytes. The search for HHV-6 replication dependent antigen, HHV-7 DNA, CMV, adenovirus, Coxsackie B1, B2, and B4-antigens, and mycobacteria was not successful. Detection of viruses was attempted using immunohistochemistry, in situ hybridization or nested polymerase chain reaction, respectively. Lymphocyte typing was carried out immunohistochemically. In GS, virus induced CNS damage does not seem to require necessarily active virus replication. It may also appear as a consequence of an immune reaction triggered by antigen expression.
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Affiliation(s)
- M Wagner
- Department of Pathology, University of Cologne Medical School, Germany
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47
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Linde A, Klapper PE, Monteyne P, Echevarria JM, Cinque P, Rozenberg F, Vestergaard BF, Ciardi M, Lebon P, Cleator GM. Specific diagnostic methods for herpesvirus infections of the central nervous system: a consensus review by the European Union Concerted Action on Virus Meningitis and Encephalitis. CLINICAL AND DIAGNOSTIC VIROLOGY 1997; 8:83-104. [PMID: 9316731 DOI: 10.1016/s0928-0197(97)00015-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Herpesvirus infections of the central nervous system are often severe but are fortunately rare. The incidence of these infections has however, increased in recent years as a consequence of an increase in the number of immune-compromised individuals. New diagnostic procedures have improved our ability to diagnose these infections and herpesviruses may yet be implicated as the cause of further neurological diseases with no known aetiology. Methodological standards for selection and evaluation of patient materials are essential to the provision of reliable diagnosis, yet few studies have addressed this important issue. OBJECTIVES To describe and define methodological standards and reference methodology for diagnosis of herpesvirus infections of the CNS. STUDY DESIGN Information gathered by literature review. RESULTS Only for herpes simplex encephalitis is there sufficient data to allow the definition of reference methodology. Good methodological standards exist but few studies have adhered to these standards. As methods for the detection of specific intrathecal antibody synthesis are well established yet under-used in diagnostic virology, the principle of these measurements is reviewed in some detail. CONCLUSIONS Herpesvirus infections of the CNS are of increasing importance. High quality, multi-centre studies are needed to establish the value of the new diagnostic test procedures if further improvement in the diagnostic sensitivity and specificity of these procedures is to be achieved.
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Affiliation(s)
- A Linde
- Manchester Royal Infirmary, UK
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48
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Novoa LJ, Nagra RM, Nakawatase T, Edwards-Lee T, Tourtellotte WW, Cornford ME. Fulminant demyelinating encephalomyelitis associated with productive HHV-6 infection in an immunocompetent adult. J Med Virol 1997; 52:301-8. [PMID: 9210040 DOI: 10.1002/(sici)1096-9071(199707)52:3<301::aid-jmv11>3.0.co;2-l] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Human herpesvirus 6 (HHV-6), the etiologic agent of roseola in young children, has been reported to be detectable in the brain of many neurologically normal adults, although regional localization to plaques of multiple sclerosis has also been demonstrated. Large amounts of this virus were present in multifocal demyelinating white matter lesions of fulminant encephalomyelitis with seizures in a 21-year-old woman with normal immune parameters. Brain biopsy after 3 weeks of neurologic deterioration revealed a viral etiology by light and electron microscopy; the virus was identified as HHV-6 by immunohistochemistry and by polymerase chain reaction (PCR) amplification in biopsy and autopsy specimens.
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Affiliation(s)
- L J Novoa
- Department of Pathology, Harbor-UCLA Medical Center, Torrance 90509, USA
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49
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Abstract
Human herpesvirus 6 variant A (HHV-6A) and human herpesvirus 6 variant B (HHV-6B) are two closely related yet distinct viruses. These visuses belong to the Roseolovirus genus of the betaherpesvirus subfamily; they are most closely related to human herpesvirus 7 and then to human cytomegalovirus. Over 95% of people older than 2 years of age are seropositive for either or both HHV-6 variants, and current serologic methods are incapable of discriminating infection with one variant from infection with the other. HHV-6A has not been etiologically linked to any human disease, but such an association will probably be found soon. HHV-6B is the etiologic agent of the common childhood illness exanthem subitum (roseola infantum or sixth disease) and related febrile illnesses. These viruses are frequently active and associated with illness in immunocompromised patients and may play a role in the etiology of Hodgkin's disease and other malignancies. HHV-6 is a commensal inhabitant of brains; various neurologic manifestations, including convulsions and encephalitis, can occur during primary HHV-6 infection or in immunocompromised patients. HHV-6 and distribution in the central nervous system are altered in patients with multiple sclerosis; the significance of this is under investigation.
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Affiliation(s)
- D K Braun
- Eli Lilly, Lilly Corporate Center, Indianapolis, Indiana 46285, USA
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van Loon N, Dykes C, Deng H, Dominguez G, Nicholas J, Dewhurst S. Identification and analysis of a lytic-phase origin of DNA replication in human herpesvirus 7. J Virol 1997; 71:3279-84. [PMID: 9060695 PMCID: PMC191464 DOI: 10.1128/jvi.71.4.3279-3284.1997] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Human herpesvirus 7 (HHV-7) DNA sequences colinear with the HHV-6 lytic-phase origin of DNA replication (oriLyt) were amplified by PCR. Plasmid constructs containing these sequences were replicated in HHV-7-infected cord blood mononuclear cells but not in HHV-6-infected cells. In contrast, plasmids bearing HHV-6 oriLyt were replicated in both HHV-6- and HHV-7-infected cells. Finally, the minimal HHV-7 DNA element necessary for replicator activity was mapped to a 600-bp region which contains two sites with high homology to the consensus binding site for the HHV-6 origin binding protein. At least one of these binding sites was shown to be essential for replicator function of HHV-7 oriLyt.
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Affiliation(s)
- N van Loon
- Department of Microbiology and Immunology, Medical Center, University of Rochester, New York 14642, USA
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