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Kasimir F, Toomey D, Liu Z, Kaiping AC, Ariza ME, Prusty BK. Tissue specific signature of HHV-6 infection in ME/CFS. Front Mol Biosci 2022; 9:1044964. [PMID: 36589231 PMCID: PMC9795011 DOI: 10.3389/fmolb.2022.1044964] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 12/05/2022] [Indexed: 12/15/2022] Open
Abstract
First exposure to various human herpesviruses (HHVs) including HHV-6, HCMV and EBV does not cause a life-threatening disease. In fact, most individuals are frequently unaware of their first exposure to such pathogens. These herpesviruses acquire lifelong latency in the human body where they show minimal genomic activity required for their survival. We hypothesized that it is not the latency itself but a timely, regionally restricted viral reactivation in a sub-set of host cells that plays a key role in disease development. HHV-6 (HHV-6A and HHV-6B) and HHV-7 are unique HHVs that acquire latency by integration of the viral genome into sub-telomeric region of human chromosomes. HHV-6 reactivation has been linked to Alzheimer's Disease, Chronic Fatigue Syndrome, and many other diseases. However, lack of viral activity in commonly tested biological materials including blood or serum strongly suggests tissue specific localization of active HHV-6 genome. Here in this paper, we attempted to analyze active HHV-6 transcripts in postmortem tissue biopsies from a small cohort of ME/CFS patients and matched controls by fluorescence in situ hybridization using a probe against HHV-6 microRNA (miRNA), miR-aU14. Our results show abundant viral miRNA in various regions of the human brain and associated neuronal tissues including the spinal cord that is only detected in ME/CFS patients and not in controls. Our findings provide evidence of tissue-specific active HHV-6 and EBV infection in ME/CFS, which along with recent work demonstrating a possible relationship between herpesvirus infection and ME/CFS, provide grounds for renewed discussion on the role of herpesviruses in ME/CFS.
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Affiliation(s)
- Francesca Kasimir
- Institute for Virology and Immunobiology, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Danny Toomey
- HHV-6 Foundation, Santa Barbara, CA, United States
| | - Zheng Liu
- Institute for Virology and Immunobiology, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Agnes C. Kaiping
- Institute for Virology and Immunobiology, Julius-Maximilians-University of Würzburg, Würzburg, Germany
| | - Maria Eugenia Ariza
- Department of Cancer Biology and Genetics (CBG), Institute for Behavioral Medicine Research (IBMR), The Ohio State University, Columbus, OH, United States
| | - Bhupesh K. Prusty
- Institute for Virology and Immunobiology, Julius-Maximilians-University of Würzburg, Würzburg, Germany,*Correspondence: Bhupesh K. Prusty,
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Bayturan S, Sapmaz ŞY, Uzun AD, Kandemir H, Ecemiş T. Relationship of herpesvirus (HSV1, EBV, CMV, HHV6) seropositivity with depressive disorder and its clinical aspects: The first study in children. J Med Virol 2022; 94:5484-5491. [PMID: 35821494 DOI: 10.1002/jmv.27995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 06/24/2022] [Accepted: 06/29/2022] [Indexed: 12/15/2022]
Abstract
Infections can lead to the onset of mood disorders in adults, partly through inflammatory mechanisms. However pediatric data are lacking. The aim of this study is to evaluate the relationship between depressive disorder and seropositivity of herpes virus infections in children. The sample group consisted of patients diagnosed with depressive disorder according to DSM-5 diagnostic criteria and healthy volunteers, being between 11 and 18 years with clinically normal mental capacity. All children completed DSM-5-Level-2 Depression Scale, DSM-5-Level-2 Irritability Scale, DSM-5-Level-2 Sleep Scale, DSM-5-Level-2 Somatic Symptoms Scale. The levels of anti-HSV1-IgG, anti-CMV-IgG, anti-EBNA, and anti-HHV6-IgG were examined in all participants. Patients with an antibody value above the cut-off values specified in the test kits were evaluated as seropositive. The mean age was 15.54 ± 1.57 years in the depression group (DG), 14.87 ± 1.76 years in the healthy control group (CG). There were 4 boys (11.2%), 32 girls (88.8%) in the DG, 9 boys (21.9%) and 32 girls (78.04%) in the CG. There was no statistically significant difference between the groups in terms of the presence of seropositivity of HSV1, CMV, EBV, and HHV6. HHV6 antibody levels were significantly higher in the DG (p = 0.000). A significant positive correlation was found between HHV6 antibodies and DSM-5 level-2 somatic symptoms scale score. HHV6 antibody levels were found to be significantly higher in patients with existing suicidal ideation in the DG (n = 13) compared to those without existing suicidal ideation in the DG (p = 0.043). HHV6 persistent infections may be responsible for somatic symptoms and etiology of suicidal ideation in childhood depressive disorder.
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Affiliation(s)
- Semra Bayturan
- Department of Pediatrics, School of Medicine, Division of Pediatric Infectious Disease, Manisa Celal Bayar University, Manisa, Turkey
| | - Şermin Yalın Sapmaz
- Department of Child and Adolescent Psychiatry, School of Medicine, Manisa Celal Bayar University, Manisa, Turkey
| | - Aylin Deniz Uzun
- Department of Child and Adolescent Psychiatry, School of Medicine, Manisa Celal Bayar University, Manisa, Turkey
| | - Hasan Kandemir
- Department of Child and Adolescent Psychiatry, School of Medicine, Manisa Celal Bayar University, Manisa, Turkey
| | - Talat Ecemiş
- Department of Microbiology, School of Medicine, Manisa Celal Bayar University, Manisa, Turkey
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Wang JQ, Yang HY, Shao X, Jiang XY, Li JM. Latent, Early or Late Human Herpes Virus-6B Expression in Adult Mesial Temporal Lobe Epilepsy: Association of Virus Life Cycle with Inflammatory Cytokines in Brain Tissue and Cerebral Spinal Fluid. Neuroscience 2022; 504:21-32. [PMID: 36067950 DOI: 10.1016/j.neuroscience.2022.08.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 08/08/2022] [Accepted: 08/25/2022] [Indexed: 10/31/2022]
Abstract
BACKGROUND Human herpes virus-6B (HHV-6B) was suggested as an important etiologic factor of mesial temporal lobe epilepsy, while the mechanism is still unknown. Here, we aimed to analyze antigens representing latent, early and late HHV-6B infection and the association with inflammatory cytokines in brain tissue and cerebral spinal fluid (CSF) from MTLE patients with HHV-6B-positivity. METHODS Nested polymerase chain reaction (nPCR), real-time PCR, immunohistochemistry (ICH) and suspension bead array for cytokines were performed. RESULTS Nested polymerase chain reaction (nPCR) in brain tissue revealed HHV-6B DNA in 19 of 49 MTLE patients (39%) and 1 of 19 controls (5%) (P < 0.001), but not in CSF. ICH showed HHV-6B early antigen (P41) positivity in 3 patients (6%), late antigen (gp116/54/64) positivity in 5 patients (10%), latent antigen (U94) positivity in 8 patients (16%), and multiple antigen (early and late or/and latent) positivity in 9 patients (18%). None of these HHV-6B related proteins were found positive in control brain tissue. PCR revealed significant up-regulation of IL-1a, IL-2 and IL-7 mRNA levels in the brain tissue from MTLE patients expressing early antigens compared to those expressing late, latent, multiple antigens, negative antigens and the controls. Suspension bead array of the CSF confirmed significant up-regulation of IL-1a and IL-7 protein expression from MTLE patients expressing early antigens compared to the other groups. CONCLUSIONS Our finding suggests HHV-6B is a common etiologic agent of MTLE. Different virus life cycle may play an important modifying role in inflammatory biology that warrants further investigation. Though virus DNA is difficult detected in CSF, up-regulation of IL-1a and IL-7 in CSF indicates the two cytokines may be taken as indirect biomarker of HHV-6B infection.
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Affiliation(s)
- Jia-Qi Wang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Hong-Yu Yang
- University of Electronic Science and Technology of China Hospital, China
| | | | - Xin-Yue Jiang
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China; Chengdu Second People's Hospital, Chengdu, Sichuan Province, China
| | - Jin-Mei Li
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.
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Kawamura Y, Maesawa S, Numoto S, Saito R, Yoshikawa T, Okumura A. Human herpesvirus 6 DNA was not detected in a brain specimen from a patient with mesial temporal sclerosis after status epilepticus due to human herpesvirus 6 infection. Epilepsia Open 2022; 7:817-821. [PMID: 35916714 PMCID: PMC9712467 DOI: 10.1002/epi4.12634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 07/28/2022] [Indexed: 12/30/2022] Open
Abstract
We performed virological analysis of resected brain tissues from a patient with temporal lobe epilepsy associated with mesial temporal sclerosis after febrile status epilepticus caused by human herpesvirus 6 infection. The patient had febrile status epilepticus at 9 months of age associated with human herpesvirus 6 infection. Magnetic resonance imaging revealed reduced water diffusion in the right temporal lobe and hippocampus. Polymerase chain reaction analysis detected 1.6 × 105 copies/μg of human herpesvirus 6 DNA in whole blood, but none in the cerebrospinal fluid. The patient developed temporal lobe epilepsy associated with mesial temporal sclerosis at 67 months of age, necessitating surgical treatment. Anterior temporal lobectomy was performed at 171 months of age. Real-time polymerase chain reaction analysis of resected brain tissues revealed no viral DNA. In our patient, human herpesvirus 6 infection triggered febrile status epilepticus, while direct evidence to prove contribution of HHV-6 to the development of MTS was not obtained.
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Affiliation(s)
- Yoshiki Kawamura
- Department of PediatricsFujita Health University School of MedicineAichiJapan
| | - Satoshi Maesawa
- Department of NeurosurgeryNagoya University Graduate School of MedicineAichiJapan
| | - Shingo Numoto
- Department of PediatricsAichi Medical UniversityAichiJapan
| | - Ryuta Saito
- Department of NeurosurgeryNagoya University Graduate School of MedicineAichiJapan
| | - Tetsushi Yoshikawa
- Department of PediatricsFujita Health University School of MedicineAichiJapan
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Tong J, Zou Q, Wang S, Liu J, Chen R, Chen Y, Zhao W, Ma L, Li Q. Human herpesvirus 6B infection in mesial temporal lobe epilepsy: a meta-analysis. ACTA EPILEPTOLOGICA 2022. [DOI: 10.1186/s42494-022-00083-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Whether human herpesvirus 6B (HHV-6B) can affect mesial temporal lobe epilepsy (MTLE) remains controversial. The present meta-analysis was aimed to evaluate whether HHV-6B is significantly associated with MTLE.
Methods
Six studies were included in this meta-analysis, comprising 183 MTLE patients and 75 controls. In these studies, HHV-6B infection in astrocytes and brain samples of MTLE patients and controls was investigated by polymerase chain reaction and immunofluorescence.
Results
The frequency of HHV-6B infection detection is significantly higher in the MTLE group than in the control group (OR = 9.42, 95%CI: 3.66–24.25), P < 0.00001). Although febrile convulsion is strongly associated with MTLE, the formation of febrile convulsion leading to MTLE is not associated with HHV-6B infection (OR = 2.68, 95%CI: 0.93–7.73), P = 0.07). Moreover, the HHV-6B-specific antigen is co-localized to cells positive for GFAP that morphologically resemble astrocytes. HHV-6B mainly infects astrocytes, oligodendrocytes and microglia, and could damage the vascular endothelial cells of the central nervous system.
Conclusions
There is an association between HHV-6B infection and MTLE. Future large-scale, multi-center, controlled, prospective studies are required to confirm these findings. In addition, the exact mechanism underlying the effects of HHV-6B infection on MTLE needs to be further investigated.
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Theodore WH, Leibovitch E, Billioux BJ, Inati SK, Zaghloul K, Heiss J, Gaillard WD, Jacobson S. Human herpesvirus 6 and epilepsy. Epilepsia Open 2021; 6:777-780. [PMID: 34324277 PMCID: PMC8633468 DOI: 10.1002/epi4.12531] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/21/2021] [Accepted: 07/22/2021] [Indexed: 01/12/2023] Open
Abstract
We investigated the association between human herpesvirus 6 (HHV‐6) and mesial temporal sclerosis (MTS) in 87 patients who had surgery for drug‐resistant epilepsy. Fifty‐four had MTS, 22 focal cortical dysplasia (FCD), four tumors, three vascular malformations, and three a history of encephalitis. We extracted DNA from fresh brain tissue immediately after surgery and performed viral detection with quantitative real‐time polymerase chain reaction (PCR) or digital droplet PCR specific for HHV‐6A and HHV‐6B. Tissue was studied with standard clinical techniques, including hematoxylin and eosin, glial fibrillary acidic protein, and NeuN stains. Twenty‐nine of 54 patients with MTS, six of 23 with focal cortical dysplasia (FCD), and one of three with a history of encephalitis were positive for HHV‐6 (P < .02). Febrile seizure history was not associated with HHV‐6 detection. Patients with MTS had significantly lower seizure onset age than those with other pathologies. Thirteen patients had positron emission tomography with [11C]PBR28, a marker for reactive astrocytes and activated microglia; there was a trend for HHV‐6‐positive patients to have higher binding in their seizure foci, suggesting inflammation. Our study supports a potential role for HHV‐6 in the etiology of MTS.
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Affiliation(s)
- William H Theodore
- Division of Intramural Research, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Emily Leibovitch
- Division of Intramural Research, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Bridgette J Billioux
- Division of Intramural Research, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Sara K Inati
- Division of Intramural Research, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - Kareem Zaghloul
- Division of Intramural Research, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - John Heiss
- Division of Intramural Research, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
| | - William D Gaillard
- Department of Neurology, Children's National Medical Center, Washington, DC, USA
| | - Steven Jacobson
- Division of Intramural Research, National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA
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Analysis of autoantibody spectrum and human herpesvirus 6 in adult patients with 'early' versus 'late' diagnosis of 'possible limbic encephalitis'. Epilepsy Res 2021; 176:106698. [PMID: 34246119 DOI: 10.1016/j.eplepsyres.2021.106698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 06/11/2021] [Accepted: 06/19/2021] [Indexed: 11/22/2022]
Abstract
New onset temporal seizures are increasingly encountered in adult patients. Many of those fulfill diagnostic criteria for possible or definite limbic encephalitis (LE). LE is associated with autoantibodies (autoABs) against neuronal surface structures ('neuronal' autoABs), 'onconeuronal' or GAD65. AutoABs can emerge in a paraneoplastic setting. However, by far not all patients with possible/definite LE have an oncological history. AutoABs have also found to arise in the context of viral encephalitis. Rare associations between autoAB-positive LE and human herpes virus 6 (HHV-6) infection have been as well reported. Our present analysis was dedicated to learn about potentially different autoAB spectra and HHV-6 detection rates in adult-onset temporal seizure patients with possible LE and largely different time spans between first seizure events and referral to a tertiary epileptological center due to pharmacoresistent seizures. We scrutinized serum/CSF samples obtained from adults with 'early diagnosis' of possible LE (≤ 30 months after first seizure event; n = 94) versus a patient group with 'late diagnosis' of possible LE (≥ 97 months; n = 45) for the presence of autoABs and HHV-6 DNA. AutoABs were detected in CSF and/or serum samples (n = 20) in 21.3 % of the early diagnosis patients with the highest abundance of anti-LGI1 (n = 8), significantly more frequent than in the late diagnosis group (autoAB positive: n = 4 (8.9 %); *p < 0.05, Fisher's Exact Test). Quantitative PCR revealed viral HHV-6 DNA in only one serum sample of the early diagnosis cohort but no evidence in corresponding CSF samples or in any sample of the late diagnosis group. The present data demonstrate a higher incidence of distinct autoABs in adults with early diagnosis of possible LE. The distinct spectra of autoABs have to be taken into account in the differential diagnosis of possible LE patients with short versus more sustained duration of temporal seizure activity.
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Abstract
AbstractHuman herpes virus 6 (HHV-6) is a ubiquitous and most common pathogen that affects humans. Human herpes virus 6B (HHV-6B) is a wide spread human herpesvirus that infects most people when they are children, establishes latent infections in the central nervous system (CNS), especially in the hippocampus and amygdala, and induces neurologic diseases. HHV-6 can establish a latent infection and be reactivated by various stimuli. Recently, viral genomic DNA of HHV-6B has been detected in surgically removed brain tissues of intractable epilepsy patients, suggesting the involvement of HHV-6B in the pathogenesis of epilepsy. Temporal lobe epilepsy (TLE) has been shown to be closely related with HHV-6B. TLE patients with HHV-6B in their brains suffer from reiterative attacks of febrile seizures and hippocampal sclerosis. However, the mechanisms underlying the contribution of this virus to the development of TLE remains unknown. The direct damage and immune activation caused by the virus are involved in the process of neuron damage, abnormal neural circuit formation and glial cell proliferation. In addition, some cytokines like interleukin-17A (IL-17A), nuclear factor-kappa B (NF-κb), transforming growth factor-β (TGF-β), mitogen-activated protein kinase (MAPK) and phospholipase A2 are up-regulated and involved in the pathological process of TLE. More studies are needed to clarify the mechanisms underlying the link between HHV-6B and epilepsy, and identify biomarkers to recognize different patient groups for anti-inflammatory or immunomodulatory therapies.
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Wouk J, Rechenchoski DZ, Rodrigues BCD, Ribelato EV, Faccin-Galhardi LC. Viral infections and their relationship to neurological disorders. Arch Virol 2021; 166:733-753. [PMID: 33502593 PMCID: PMC7838016 DOI: 10.1007/s00705-021-04959-6] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/27/2020] [Indexed: 01/26/2023]
Abstract
The chronic dysfunction of neuronal cells, both central and peripheral, a characteristic of neurological disorders, may be caused by irreversible damage and cell death. In 2016, more than 276 million cases of neurological disorders were reported worldwide. Moreover, neurological disorders are the second leading cause of death. Generally, the etiology of neurological diseases is not fully understood. Recent studies have related the onset of neurological disorders to viral infections, which may cause neurological symptoms or lead to immune responses that trigger these pathological signs. Currently, this relationship is mostly based on epidemiological data on infections and seroprevalence of patients who present with neurological disorders. The number of studies aiming to elucidate the mechanism of action by which viral infections may directly or indirectly contribute to the development of neurological disorders has been increasing over the years but these studies are still scarce. Comprehending the pathogenesis of these diseases and exploring novel theories may favor the development of new strategies for diagnosis and therapy in the future. Therefore, the objective of the present study was to review the main pieces of evidence for the relationship between viral infection and neurological disorders such as Alzheimer's disease, Parkinson's disease, Guillain-Barré syndrome, multiple sclerosis, and epilepsy. Viruses belonging to the families Herpesviridae, Orthomyxoviridae, Flaviviridae, and Retroviridae have been reported to be involved in one or more of these conditions. Also, neurological symptoms and the future impact of infection with SARS-CoV-2, a member of the family Coronaviridae that is responsible for the COVID-19 pandemic that started in late 2019, are reported and discussed.
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Affiliation(s)
- Jéssica Wouk
- Post-Graduation Program of Pharmaceutical Science, Midwest State University, CEDETEG Campus, Guarapuava, Paraná Brazil
| | | | | | - Elisa Vicente Ribelato
- Department of Microbiology, Biological Science Center, Londrina State University, Londrina, Paraná Brazil
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Komaroff AL, Pellett PE, Jacobson S. Human Herpesviruses 6A and 6B in Brain Diseases: Association versus Causation. Clin Microbiol Rev 2020; 34:e00143-20. [PMID: 33177186 PMCID: PMC7667666 DOI: 10.1128/cmr.00143-20] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Human herpesvirus 6A (HHV-6A) and human herpesvirus 6B (HHV-6B), collectively termed HHV-6A/B, are neurotropic viruses that permanently infect most humans from an early age. Although most people infected with these viruses appear to suffer no ill effects, the viruses are a well-established cause of encephalitis in immunocompromised patients. In this review, we summarize the evidence that the viruses may also be one trigger for febrile seizures (including febrile status epilepticus) in immunocompetent infants and children, mesial temporal lobe epilepsy, multiple sclerosis (MS), and, possibly, Alzheimer's disease. We propose criteria for linking ubiquitous infectious agents capable of producing lifelong infection to any neurologic disease, and then we examine to what extent these criteria have been met for these viruses and these diseases.
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Affiliation(s)
- Anthony L Komaroff
- Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Philip E Pellett
- Department of Microbiology and Immunology, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Steven Jacobson
- Virology/Immunology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
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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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Akinsoji EO, Leibovitch E, Billioux BJ, Abath Neto OL, Ray-Chaudhury A, Inati SK, Zaghloul K, Heiss J, Jacobson S, Theodore WH. HHV-6 and hippocampal volume in patients with mesial temporal sclerosis. Ann Clin Transl Neurol 2020; 7:1674-1680. [PMID: 33325656 PMCID: PMC7480901 DOI: 10.1002/acn3.51152] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 07/16/2020] [Indexed: 12/11/2022] Open
Abstract
Objective To study the effects of human herpes virus 6 (HHV‐6) on the hippocampal volume in patients with mesial temporal sclerosis (MTS). Background HHV‐6 may play an etiologic role in MTS. Previous studies found a possible association with febrile status epilepticus. Several investigators have reported a higher prevalence of HHV‐6 in MTS resections compared to other epilepsy etiologies. Design/Methods We used FreeSurfer to segment cortical structures and obtain whole hippocampal and subfield volumes in 41 patients with intractable epilepsy. In addition, an investigator blinded to other data traced hippocampi manually on each slice. The main study outcome measure was the asymmetry index (AI) between hippocampal volumes ipsilateral and contralateral to seizure foci compared between HHV‐6 positive and negative patients. Viral DNA was isolated from fresh brain tissue obtained at temporal lobectomy. For 25 patients, viral detection was performed using quantitative real‐time PCR specific for HHV‐6A and HHV‐6B. For 16 patients, viral DNA detection was performed using digital droplet PCR specific for HHV‐6A and HHV‐6B. Results Twenty‐two patients were positive (14 of 25 tested with real‐time PCR, and 8 of 16 with digital droplet PCR), and 19 negatives for HHV‐6. HHV‐6 negative patients had significantly greater AI and lower total hippocampal volume ipsilateral to seizure foci than HHV‐6 positive patients. Epilepsy duration and age of onset did not affect results. Interpretation Our data suggest multiple potential etiologies for MTS. HHV‐6 may have a less severe effect on the hippocampus than other etiologies.
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Affiliation(s)
- Elizabeth O Akinsoji
- Clinical Epilepsy Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland
| | - Emily Leibovitch
- Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland
| | - B Jeanne Billioux
- Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland
| | - Osorio Lopes Abath Neto
- National Institute of Neurological Disorders and Stroke, National Cancer Institute, NIH, Bethesda, Maryland
| | - Abhik Ray-Chaudhury
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland
| | - Sara K Inati
- EEG Laboratory, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland
| | - Kareem Zaghloul
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland
| | - John Heiss
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland
| | - Steven Jacobson
- Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland
| | - William H Theodore
- Clinical Epilepsy Section, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland
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13
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Persistent Roseoloviruses Infection in Adult Patients with Epilepsy. Brain Sci 2020; 10:brainsci10050287. [PMID: 32403392 PMCID: PMC7288180 DOI: 10.3390/brainsci10050287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 05/08/2020] [Accepted: 05/09/2020] [Indexed: 12/31/2022] Open
Abstract
Background: Human herpesviruses (HHV)-6A, HHV-6B and HHV-7 are considered to be involved in the pathogenesis of epilepsy, a common neurological disorder. The objective of this study was to determine the association of roseoloviruses infection with epilepsy. Methods: 53 epilepsy patients and 104 ordinary blood donors were analyzed to determine presence of virus-specific antibodies by enzyme-linked immunosorbent assay (ELISA) and immunofluorescence assay (IFA), genomic sequences, viral load and gene expression by polymerase chain reactions (PCRs) and restriction analysis, HHV-6 protein expression by IFA and level of cytokines by ELISA. Results: Roseoloviruses genomic sequences in DNA samples from whole blood were found in 86.8% of patients versus 54.8% of controls and active infection was revealed only in patients with epilepsy (19.6% of roseolovirus-positive patients). Significantly higher viral load and more frequent gene expression was detected in patients compared to the controls. HHV-6-encoded protein expression was demonstrated in 53.3% of patients with previously detected HHV-6 DNA. Changes in level of cytokines were determined in patients with elevated viral load compared to the patients without elevated viral loads and to the controls. Conclusions: Results on frequent active HHV-6 and HHV-7 infection in epilepsy patient’ peripheral blood indicate on possible involvement of these viruses in the disease development.
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14
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HHV-6-Associated Neurological Disease in Children: Epidemiologic, Clinical, Diagnostic, and Treatment Considerations. Pediatr Neurol 2020; 105:10-20. [PMID: 31932119 DOI: 10.1016/j.pediatrneurol.2019.10.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 10/12/2019] [Accepted: 10/17/2019] [Indexed: 02/04/2023]
Abstract
Human herpesviruses 6A and 6B, often referred to collectively as human herpesvirus 6, are a pair of beta-herpesviruses known to cause a variety of clinical syndromes in both immunocompetent and immunocompromised individuals. Most humans are infected with human herpesvirus 6B, and many with human herpesvirus 6A. Primary infection typically occurs in early childhood, although large-scale reviews on the topic are limited. Herein, the authors explore the clinical manifestations of human herpesvirus 6-associated disease in both immunocompetent and immunocompromised pediatric patients, the risk factors for development of human herpesvirus 6-associated neurological disease, the risk of autoimmunity associated with development of active or latent infection, the relevance of human herpesvirus 6-specific diagnostic tests, and the medications used to treat human herpesvirus 6. The goal of this review is to improve the current understanding of human herpesvirus 6 in pediatric populations and to examine the most effective diagnostic and therapeutic interventions in this disease state.
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15
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Braganza O. A simple model suggesting economically rational sample-size choice drives irreproducibility. PLoS One 2020; 15:e0229615. [PMID: 32160229 PMCID: PMC7065751 DOI: 10.1371/journal.pone.0229615] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 02/10/2020] [Indexed: 11/30/2022] Open
Abstract
Several systematic studies have suggested that a large fraction of published research is not reproducible. One probable reason for low reproducibility is insufficient sample size, resulting in low power and low positive predictive value. It has been suggested that insufficient sample-size choice is driven by a combination of scientific competition and 'positive publication bias'. Here we formalize this intuition in a simple model, in which scientists choose economically rational sample sizes, balancing the cost of experimentation with income from publication. Specifically, assuming that a scientist's income derives only from 'positive' findings (positive publication bias) and that individual samples cost a fixed amount, allows to leverage basic statistical formulas into an economic optimality prediction. We find that if effects have i) low base probability, ii) small effect size or iii) low grant income per publication, then the rational (economically optimal) sample size is small. Furthermore, for plausible distributions of these parameters we find a robust emergence of a bimodal distribution of obtained statistical power and low overall reproducibility rates, both matching empirical findings. Finally, we explore conditional equivalence testing as a means to align economic incentives with adequate sample sizes. Overall, the model describes a simple mechanism explaining both the prevalence and the persistence of small sample sizes, and is well suited for empirical validation. It proposes economic rationality, or economic pressures, as a principal driver of irreproducibility and suggests strategies to change this.
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Affiliation(s)
- Oliver Braganza
- Institute for Experimental Epileptology and Cognition Research, University of Bonn, Bonn, Germany
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16
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Asadi-Pooya AA, Bartolini L. Prevention and treatment of temporal lobe epilepsy: lessons from hepatitis B story! Int J Neurosci 2020; 130:1151-1155. [PMID: 32053411 DOI: 10.1080/00207454.2020.1730370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Temporal lobe epilepsy (TLE) is the most common type of drug-resistant epilepsy and hippocampal sclerosis (HS) is the most common pathological substrate of TLE. Considering the significant consequences of uncontrolled seizures (e.g. increased morbidity and mortality), epilepsy prevention remains a necessity that potentially could save many lives. Human herpes virus-6 (HHV-6) has been linked to TLE in humans. The relationship between HHV-6 and HS-TLE could be attributed to a neuro-inflammatory cascade triggered by the infection, involving direct neuronal damage and production of several pro-inflammatory cytokines under certain conditions that are still incompletely understood. Hepatitis B virus (HBV) infection is another chronic viral infection with a life-long latency. HBV infection is linked to various clinical conditions, including liver cirrhosis. There are currently three ways to fight HBV infection and its consequences; primary prevention (by vaccination), secondary prevention (by drug therapy), and tertiary prevention (by liver transplantation). Considering the similarities between the natural histories of HHV-6 and HBV infections, and also the successful strategies which are currently available to fight HBV infection and its long-term consequences, here, we propose three strategies to fight HHV-6 and its possible long-term consequence (i.e. HS-TLE): Primary prevention: by developing vaccines to prevent HHV-6 infection; Secondary prevention: by considering trials of antiviral drugs to treat HHV-6 infection, when it happens in the childhood to hopefully prevent its long-term consequences; and, Tertiary prevention: by stem cell therapy for drug-resistant epilepsy.
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Affiliation(s)
- Ali A Asadi-Pooya
- Epilepsy Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.,Jefferson Comprehensive Epilepsy Center, Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Luca Bartolini
- Hasbro Children's Hospital/Alpert Medical School of Brown University, Providence, RI, USA
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17
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Prusty BK, Gulve N, Govind S, Krueger GRF, Feichtinger J, Larcombe L, Aspinall R, Ablashi DV, Toro CT. Active HHV-6 Infection of Cerebellar Purkinje Cells in Mood Disorders. Front Microbiol 2018; 9:1955. [PMID: 30186267 PMCID: PMC6110891 DOI: 10.3389/fmicb.2018.01955] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 08/02/2018] [Indexed: 12/25/2022] Open
Abstract
Early-life infections and associated neuroinflammation is incriminated in the pathogenesis of various mood disorders. Infection with human roseoloviruses, HHV-6A and HHV-6B, allows viral latency in the central nervous system and other tissues, which can later be activated causing cognitive and behavioral disturbances. Hence, this study was designed to evaluate possible association of HHV-6A and HHV-6B activation with three different groups of psychiatric patients. DNA qPCR, immunofluorescence and FISH studies were carried out in post-mortem posterior cerebellum from 50 cases each of bipolar disorder (BPD), schizophrenia, 15 major depressive disorder (MDD) and 50 appropriate control samples obtained from two well-known brain collections (Stanley Medical Research Institute). HHV-6A and HHV-6B late proteins (indicating active infection) and viral DNA were detected more frequently (p < 0.001 for each virus) in human cerebellum in MDD and BPD relative to controls. These roseolovirus proteins and DNA were found less frequently in schizophrenia cases. Active HHV-6A and HHV-6B infection in cerebellar Purkinje cells were detected frequently in BPD and MDD cases. Furthermore, we found a significant association of HHV-6A infection with reduced Purkinje cell size, suggesting virus-mediated abnormal Purkinje cell function in these disorders. Finally, gene expression analysis of cerebellar tissue revealed changes in pathways reflecting an inflammatory response possibly to HHV-6A infection. Our results provide molecular evidence to support a role for active HHV-6A and HHV-6B infection in BPD and MDD.
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Affiliation(s)
- Bhupesh K Prusty
- Biocenter, Department of Microbiology, University of Würzburg, Würzburg, Germany.,Institute for Virology and Immunobiology, University of Würzburg, Würzburg, Germany
| | - Nitish Gulve
- Biocenter, Department of Microbiology, University of Würzburg, Würzburg, Germany
| | - Sheila Govind
- Division of Virology, National Institute for Biological Standards and Control, Hertfordshire, United Kingdom
| | - Gerhard R F Krueger
- Department of Pathology and Laboratory Medicine, UT-Houston Medical School, Houston, TX, United States
| | - Julia Feichtinger
- Institute of Computational Biotechnology, Graz University of Technology, Graz, Austria.,BioTechMed Omics Center, Graz, Austria
| | - Lee Larcombe
- Applied Exomics Ltd., Stevenage Bioscience Catalyst, Stevenage, United Kingdom
| | - Richard Aspinall
- Faculty of Health and Life Sciences, Coventry University, Coventry, United Kingdom
| | | | - Carla T Toro
- HHV-6 Foundation, Santa Barbara, CA, United States.,The Institute of Digital Healthcare, The University of Warwick, Warwick, United Kingdom
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18
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Engdahl E, Niehusmann P, Fogdell-Hahn A. The effect of human herpesvirus 6B infection on the MAPK pathway. Virus Res 2018; 256:134-141. [PMID: 30130603 DOI: 10.1016/j.virusres.2018.08.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 08/03/2018] [Accepted: 08/16/2018] [Indexed: 12/24/2022]
Abstract
BACKGROUND Human herpesvirus 6B (HHV-6B) is a neurotropic virus that has been repeatedly associated with mesial temporal lobe epilepsy (MTLE). However, the mechanism behind this suggested association is not known. Therefore, the aim of this study was to investigate what genes were affected by HHV-6B, possibly revealing HHV-6B induced disease causing mechanisms. MATERIAL AND METHOD First, gene expression in MTLE tissue positive for HHV-6B DNA (n = 10) and negative for HHV-6B DNA (n = 14) was compared using the Affymetrix® Human Gene 2.1 ST Array. Secondly, in vitro experiments were conducted where Molt-3 T cells were infected with HHV-6B and gene expression of MAP2K4 (MKK4) and 89 other genes in the MAPK signaling pathway was investigated using qPCR. In addition, phosphorylated MKK4 was assessed using IFA and the DNA methylation investigated with Illumina Infinium HumanMethylation450 BeadChip array. RESULTS MAP2K4 was one of the most differently expressed genes in the Affymetrix array, suggesting an upregulation by HHV-6B infection in MTLE tissue. No gene reached statistical significance but MAP2K4 was selected for further investigation in vitro, where it was clearly upregulated by HHV-6B infection both on gene expression and protein expression level. Further investigating expression of genes in the MAPK pathways in vitro revealed that several genes were affected by HHV-6B infection, but none of these genes displayed viral induced changes in DNA methylation. CONCLUSIONS As the MAPK pathways are involved in transforming different stimuli (like stress) into a cellular responses (like apoptosis or inflammation), it may not be surprising that genes in these pathways are affected by virus infection. This is the first report of HHV-6B's effect on these signaling cascades and given that both dysregulation of the MAPK pathways and an association with HHV-6B have been previously observed in epilepsy, a possible link of infection induced dysregulation of MAPK in epilepsy warrant further investigation.
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Affiliation(s)
- Elin Engdahl
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Pitt Niehusmann
- Department of Neurology/Pathology, Oslo University Hospital, 0450, Oslo, Norway; Department of Neuropathology, University of Bonn Medical Center, 53113, Bonn, Germany
| | - Anna Fogdell-Hahn
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
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19
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Wipfler P, Dunn N, Beiki O, Trinka E, Fogdell-Hahn A. The Viral Hypothesis of Mesial Temporal Lobe Epilepsy – Is Human Herpes Virus-6 the Missing Link? A systematic review and meta-analysis. Seizure 2018; 54:33-40. [DOI: 10.1016/j.seizure.2017.11.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 11/21/2017] [Accepted: 11/24/2017] [Indexed: 12/26/2022] Open
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20
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Poulheim F, Esposito L, Elger CE, Eis-Hübinger AM, Becker AJ, Niehusmann P. Large-scale analysis of herpesviridae in epilepsy-patients with signs of autoimmune encephalitis. Seizure 2017; 53:100-102. [DOI: 10.1016/j.seizure.2017.11.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 11/12/2017] [Accepted: 11/16/2017] [Indexed: 12/11/2022] Open
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21
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Bauer J, Becker AJ, Elyaman W, Peltola J, Rüegg S, Titulaer MJ, Varley JA, Beghi E. Innate and adaptive immunity in human epilepsies. Epilepsia 2017; 58 Suppl 3:57-68. [PMID: 28675562 PMCID: PMC5535008 DOI: 10.1111/epi.13784] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2017] [Indexed: 01/10/2023]
Abstract
Inflammatory mechanisms have been increasingly implicated in the origin of seizures and epilepsy. These mechanisms are involved in the genesis of encephalitides in which seizures are a common complaint. Experimental and clinical evidence suggests different inflammatory responses in the brains of patients with epilepsy depending on the etiology. In general, activation of both innate and adaptive immunity plays a role in refractory forms of epilepsy. Epilepsies in which seizures develop after infiltration of cells of the adaptive immune system in the central nervous system (CNS) include a broad range of epileptic disorders with different (known or unknown) etiologies. Infiltration of lymphocytes is observed in autoimmune epilepsies, especially the classical paraneoplastic encephalitides with antibodies against intracellular tumor antigens. The presence of lymphocytes in the CNS also has been found in focal cerebral dysplasia type 2 and in cortical tubers. Various autoantibodies have been shown to be associated with temporal lobe epilepsy (TLE) and hippocampal sclerosis of unknown etiology, which may be due to the presence of viral DNA. During the last decade, an increasing number of antineuronal autoantibodies directed against membranous epitopes have been discovered and are associated with various neurologic syndromes, including limbic encephalitis. A major challenge in epilepsy is to define biomarkers, which would allow the recognition of patient populations who might benefit from immune-modulatory therapies. Some peripheral inflammatory markers appear to be differentially expressed in patients with medically controlled and medically refractory and, as such, could be used for diagnostic, prognostic, or therapeutic purposes. Establishing an autoimmune basis in patients with drug-resistant epilepsy allows for efficacious and targeted immunotherapy. Although current immunotherapies can give great benefit to the correctly identified patient, there are limitations to their efficacy and they may have considerable side effects. Thus the identification of new immunomodulatory compounds remains of utmost importance.
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Affiliation(s)
- Jan Bauer
- Department of Neuroimmunology, Center for Brain Research Medical University of Vienna, Vienna, Austria
| | - Albert J Becker
- Section for Translational Epilepsy Research, Department of Neuropathology, University of Bonn - Medical Center, Bonn, Germany
| | - Wassim Elyaman
- Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, U.S.A.,The Broad Institute, Cambridge, Massachusetts, U.S.A
| | - Jukka Peltola
- Department Neurology, Tampere University Hospital, Tampere, Finland
| | - Stephan Rüegg
- Department Neurology, University Hospital Basel, Basel, Switzerland
| | - Maarten J Titulaer
- Department Neurology, Erasmus University Medical Center, Rotterdam, The Netherlands
| | - James A Varley
- Nuffield Department Clinical Neurosciences, John Radcliffe Hospital, Oxford, United Kingdom
| | - Ettore Beghi
- IRCCS-Mario Negri Institute for Pharmacological Research, Milano, Italy
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22
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Human Herpesvirus 6B Induces Hypomethylation on Chromosome 17p13.3, Correlating with Increased Gene Expression and Virus Integration. J Virol 2017; 91:JVI.02105-16. [PMID: 28298607 DOI: 10.1128/jvi.02105-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 03/03/2017] [Indexed: 12/21/2022] Open
Abstract
Human herpesvirus 6B (HHV-6B) is a neurotropic betaherpesvirus that achieves latency by integrating its genome into host cell chromosomes. Several viruses can induce epigenetic modifications in their host cells, but no study has investigated the epigenetic modifications induced by HHV-6B. This study analyzed methylation with an Illumina 450K array, comparing HHV-6B-infected and uninfected Molt-3 T cells 3 days postinfection. Bisulfite pyrosequencing was used to validate the Illumina results and to investigate methylation over time in vitro Expression of genes was investigated using quantitative PCR (qPCR), and virus integration was investigated with PCR. A total of 406 CpG sites showed a significant HHV-6B-induced change in methylation in vitro Remarkably, 86% (351/406) of these CpGs were located <1 Mb from chromosomal ends and were all hypomethylated in virus-infected cells. This was most evident at chromosome 17p13.3, where HHV-6B had induced CpG hypomethylation after 2 days of infection, possibly through TET2, which was found to be upregulated by the virus. In addition, virus-induced cytosine hydroxymethylation was observed. Genes located in the hypomethylated region at 17p13.3 showed significantly upregulated expression in HHV-6B-infected cells. A temporal experiment revealed HHV-6B integration in Molt-3 cell DNA 3 days after infection. The telomere at 17p has repeatedly been described as an integration site for HHV-6B, and we show for the first time that HHV-6B induces hypomethylation in this region during acute infection, which may play a role in the integration process, possibly by making the DNA more accessible.IMPORTANCE The ability to establish latency in the host is a hallmark of herpesviruses, but the mechanisms differ. Human herpesvirus 6B (HHV-6B) is known to establish latency through integration of its genome into the telomeric regions of host cells, with the ability to reactivate. Our study is the first to show that HHV-6B specifically induces hypomethylated regions close to the telomeres and that integrating viruses may use the host methylation machinery to facilitate their integration process. The results from this study contribute to knowledge of HHV-6B biology and virus-host interaction. This in turn will lead to further progress in our understanding of the underlying mechanisms by which HHV-6B contributes to pathological processes and may have important implications in both disease prevention and treatment.
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23
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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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24
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Mohammadpour Touserkani F, Gaínza-Lein M, Jafarpour S, Brinegar K, Kapur K, Loddenkemper T. HHV-6 and seizure: A systematic review and meta-analysis. J Med Virol 2016; 89:161-169. [PMID: 27272972 DOI: 10.1002/jmv.24594] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2016] [Indexed: 12/26/2022]
Abstract
Human herpesvirus-6 (HHV-6) is a common infection in childhood. This systematic review aims to assess the relationship between HHV-6 infection and seizure disorders based on available literature. MEDLINE database was searched using a search strategy. We included studies that were published after 1993 in English, and described patients with HHV-6 infection and accompanying seizure or status epilepticus. We identified 503 articles, and included 147 studies. Meta-analysis results showed a 0.21 detection rate of HHV-6 in febrile seizure patients. In the febrile seizure group (110 cases), 76 patients had simple and 34 had complex febrile seizures. Patients with "HHV-6 infection and status epilepticus" had a mean age of 16.24 months. In children with febrile illnesses, a higher index of clinical suspicion for HHV-6 infection may be required. Further studies including CSF and brain tissue may be needed to validate relationships between HHV6 infection and epilepsy. J. Med. Virol. 89:161-169, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Fatemeh Mohammadpour Touserkani
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
| | - Marina Gaínza-Lein
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,Universidad Austral de Chile, Valdivia, Chile
| | - Saba Jafarpour
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Katelyn Brinegar
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.,Division of Biomedical Engineering, Department of Medicine, Biomaterials Innovation Research Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.,Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Kush Kapur
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Tobias Loddenkemper
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
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25
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Vezzani A, Fujinami RS, White HS, Preux PM, Blümcke I, Sander JW, Löscher W. Infections, inflammation and epilepsy. Acta Neuropathol 2016; 131:211-234. [PMID: 26423537 DOI: 10.1007/s00401-015-1481-5] [Citation(s) in RCA: 296] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 09/18/2015] [Accepted: 09/20/2015] [Indexed: 12/15/2022]
Abstract
Epilepsy is the tendency to have unprovoked epileptic seizures. Anything causing structural or functional derangement of brain physiology may lead to seizures, and different conditions may express themselves solely by recurrent seizures and thus be labelled "epilepsy." Worldwide, epilepsy is the most common serious neurological condition. The range of risk factors for the development of epilepsy varies with age and geographic location. Congenital, developmental and genetic conditions are mostly associated with the development of epilepsy in childhood, adolescence and early adulthood. Head trauma, infections of the central nervous system (CNS) and tumours may occur at any age and may lead to the development of epilepsy. Infections of the CNS are a major risk factor for epilepsy. The reported risk of unprovoked seizures in population-based cohorts of survivors of CNS infections from developed countries is between 6.8 and 8.3 %, and is much higher in resource-poor countries. In this review, the various viral, bacterial, fungal and parasitic infectious diseases of the CNS which result in seizures and epilepsy are discussed. The pathogenesis of epilepsy due to brain infections, as well as the role of experimental models to study mechanisms of epileptogenesis induced by infectious agents, is reviewed. The sterile (non-infectious) inflammatory response that occurs following brain insults is also discussed, as well as its overlap with inflammation due to infections, and the potential role in epileptogenesis. Furthermore, autoimmune encephalitis as a cause of seizures is reviewed. Potential strategies to prevent epilepsy resulting from brain infections and non-infectious inflammation are also considered.
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Affiliation(s)
- Annamaria Vezzani
- Department of Neuroscience, IRCCS-"Mario Negri" Institute for Pharmacological Research, Milan, Italy
| | - Robert S Fujinami
- Department of Pathology, University of Utah, Salt Lake City, UT, USA
| | - H Steve White
- Department of Pharmacology, University of Utah, Salt Lake City, UT, USA
| | - Pierre-Marie Preux
- INSERM UMR1094, Tropical Neuroepidemiology, Limoges, France
- Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, University of Limoges, Limoges, France
- Center of Epidemiology, Biostatistics, and Research Methodology, CHU Limoges, Limoges, France
| | - Ingmar Blümcke
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Josemir W Sander
- NIHR University College London Hospitals Biomedical Research Centre, UCL Institute of Neurology, London, WC1N £BG, UK
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, 30559, Hannover, Germany.
- Center for Systems Neuroscience, Hannover, Germany.
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26
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Niehusmann P, Widman G, Eis-Hübinger AM, Greschus S, Robens BK, Grote A, Becker AJ. Non-paraneoplastic limbic encephalitis and central nervous HHV-6B reactivation: Causality or coincidence? Neuropathology 2016; 36:376-80. [DOI: 10.1111/neup.12283] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 11/24/2015] [Accepted: 11/24/2015] [Indexed: 01/19/2023]
Affiliation(s)
- Pitt Niehusmann
- Department of Neurology / Pathology; Oslo University Hospital; Oslo Norway
- Department of Neuropathology; University of Bonn Medical Center; Bonn Germany
| | - Guido Widman
- Department of Epileptology; University of Bonn Medical Center; Bonn Germany
| | | | - Susanne Greschus
- Department of Radiology; University of Bonn Medical Center; Bonn Germany
| | - Barbara K. Robens
- Department of Neurology / Pathology; Oslo University Hospital; Oslo Norway
| | - Alexander Grote
- Department of Neurosurgery; University of Bonn Medical Center; Bonn Germany
| | - Albert J. Becker
- Department of Neurology / Pathology; Oslo University Hospital; Oslo Norway
- Translational Epilepsy Research Section; University of Bonn Medical Center; Bonn Germany
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27
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Chapenko S, Roga S, Skuja S, Rasa S, Cistjakovs M, Svirskis S, Zaserska Z, Groma V, Murovska M. Detection frequency of human herpesviruses-6A, -6B, and -7 genomic sequences in central nervous system DNA samples from post-mortem individuals with unspecified encephalopathy. J Neurovirol 2016; 22:488-97. [PMID: 26727906 DOI: 10.1007/s13365-015-0417-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 11/25/2015] [Accepted: 12/09/2015] [Indexed: 12/22/2022]
Abstract
In this autopsy-based study, human herpesvirus-6 (HHV-6) and -7 (HHV-7) genomic sequence frequency, HHV-6 variants, HHV-6 load and the expression of HHV-6 antigens in brain samples from the individuals, with and without unspecified encephalopathy (controls), using nested and real-time polymerase chain reactions, restriction endonuclease, and immunohistochemical analysis were examined. GraphPad Prism 6.0 Mann-Whitney nonparametric and chi-square test and Fisher's exact test were used for statistical analysis. The encephalopathy diagnoses were shown by magnetic resonance imaging made during their lifetime and macro- and microscopically studied autopsy tissue materials. Widespread HHV-6 and/or HHV-7 positivity was detected in the brain tissue of various individuals with encephalopathy, as well as in controls (51/57, 89.4 % and 35/51, 68.6 %, respectively; p = 0.009). Significantly higher detection frequency of single HHV-6 and concurrent HHV-6 + HHV-7 DNA was found in pia mater meninges, frontal lobe, temporal lobe, and olfactory tract DNAs in individuals with encephalopathy compared to the control group. HHV-6 load and higher frequency of the viral load >10 copies/10(6) cells significantly differed in samples from individuals with and without encephalopathy. The expression of HHV-6 antigens was revealed in different neural cell types with strong predominance in the encephalopathy group. In all HHV-6-positive autopsy samples of individuals with and without encephalopathy, HHV-6B was revealed. Significantly higher detection frequency of beta-herpesvirus DNA, more often detected HHV-6 load >10 copies/10(6) cells, as well as the expression of HHV-6 antigens in different brain tissue samples from individuals with encephalopathy in comparison with control group indicate on potential involvement of these viruses in encephalopathy development.
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Affiliation(s)
- Svetlana Chapenko
- August Kirchenstein Institute of Microbiology and Virology, Riga Stradins University, Ratsupites iela 5, Riga, Latvia.
| | - Silvija Roga
- Study Department, Riga Stradins University, Riga, Latvia.,Pathology Department, Riga 1st Hospital, Riga, Latvia
| | - Sandra Skuja
- Institute of Anatomy and Anthropology, Riga Stradins University, Riga, Latvia
| | - Santa Rasa
- August Kirchenstein Institute of Microbiology and Virology, Riga Stradins University, Ratsupites iela 5, Riga, Latvia
| | - Maksims Cistjakovs
- August Kirchenstein Institute of Microbiology and Virology, Riga Stradins University, Ratsupites iela 5, Riga, Latvia
| | - Simons Svirskis
- August Kirchenstein Institute of Microbiology and Virology, Riga Stradins University, Ratsupites iela 5, Riga, Latvia
| | - Zane Zaserska
- August Kirchenstein Institute of Microbiology and Virology, Riga Stradins University, Ratsupites iela 5, Riga, Latvia
| | - Valerija Groma
- Institute of Anatomy and Anthropology, Riga Stradins University, Riga, Latvia
| | - Modra Murovska
- August Kirchenstein Institute of Microbiology and Virology, Riga Stradins University, Ratsupites iela 5, Riga, Latvia
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28
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Gustafsson R, Svensson M, Fogdell-Hahn A. Modulatory effects on dendritic cells by human herpesvirus 6. Front Microbiol 2015; 6:388. [PMID: 25983728 PMCID: PMC4415433 DOI: 10.3389/fmicb.2015.00388] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Accepted: 04/15/2015] [Indexed: 11/13/2022] Open
Abstract
Human herpesvirus 6A and 6B are β-herpesviruses approaching 100% seroprevalance worldwide. These viruses are involved in several clinical syndromes and have important immunomodulatory effects. Dendritic cells (DC) are key players in innate and adaptive immunity. Accordingly, DC are implicated in the pathogenesis of many human diseases, including infections. In this review the effects of HHV-6 infection on DC will be discussed.
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Affiliation(s)
- Rasmus Gustafsson
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital Stockholm, Sweden
| | - Mattias Svensson
- Department of Medicine, Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital Stockholm, Sweden
| | - Anna Fogdell-Hahn
- Department of Clinical Neuroscience, Karolinska Institutet, Karolinska University Hospital Stockholm, Sweden
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29
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Leibovitch EC, Jacobson S. Human Herpesvirus 6 as a Viral Trigger in Mesial Temporal Lobe Epilepsy. J Infect Dis 2015; 212:1011-3. [PMID: 25840442 DOI: 10.1093/infdis/jiv162] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 03/09/2015] [Indexed: 01/24/2023] Open
Affiliation(s)
- Emily C Leibovitch
- Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland Institute for Biomedical Sciences, School of Medicine and Health Sciences, The George Washington University, Washington D.C
| | - Steven Jacobson
- Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland
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