1
|
Zhou K, Zhang L, Shen S, Lin JF, Wang JR, Zhou D, Li JM, Sima X. Neurological autoantibody prevalence in chronic epilepsy: Clinical and neuropathologic findings. Seizure 2024; 115:28-35. [PMID: 38183825 DOI: 10.1016/j.seizure.2023.12.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2023] [Revised: 12/18/2023] [Accepted: 12/25/2023] [Indexed: 01/08/2024] Open
Abstract
BACKGROUND We aimed to explore the prevalence of autoimmune antibodies (Abs) in a large consecutive series with "chronic" epilepsy and without symptoms of autoimmune encephalitis; and to compare the immunopathology of brain tissue from drug-resistant epilepsy (DRE) with and without Abs positivity. METHODS Neuronal and glial antibodies were detected in the serum of patients who were admitted to the wards of West China Hospital from October 2016 to September 2019 and had epilepsy by cell-based assays and tissue-based assays. RESULTS Twenty-one (6.8 %) of 328 patients had positive Ab findings for the following: dipeptidyl-peptidase-like protein-6 (n = 7), contactin-associated protein-like 2 (n = 5), glutamic acid decarboxylase 65 (n = 4), gamma aminobutyric acid beta receptor (n = 2), N-methyl-d-aspartate receptor (n = 2), and dopamine D2 receptor (n = 1). Antibodies were detected in 6.9 % (13/187) of epilepsy people with unknown etiology and 5.6 % (8/141) of patients with known etiology, respectively. Among 190 patients with DRE, 14 (7.3 %) patients were Abs-positive. There was no significant difference between individuals with seropositive and seronegative results in clinical manifestations, except that the history of febrile seizure was significantly more frequent in the seropositive group. Moreover, brain samples from 3 patients with Abs-positive DRE (with DPPX in 2 patients, and CASPR2 in 1 patient) and 18 patients with Abs-negative DRE were analyzed for immunopathology. We found higher expression of CD8-positive T-cells in the hippocampus of Abs-positive DRE group. CONCLUSIONS Neuronal antibodies are potentially involved in the process of "chronic" epilepsy, and CD8-positive T-cells may play an important role in this process.
Collapse
Affiliation(s)
- Kui Zhou
- Department of Neurology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, Sichuan 610041, China
| | - Le Zhang
- Department of Neurology, The Third Xiangya Hospital of Central South University, Changsha, China
| | - Sisi Shen
- Department of Neurology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, Sichuan 610041, China
| | - Jing-Fang Lin
- Department of Neurology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, Sichuan 610041, China
| | - Jie-Rui Wang
- Department of Neurology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, Sichuan 610041, China
| | - Dong Zhou
- Department of Neurology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, Sichuan 610041, China
| | - Jin-Mei Li
- Department of Neurology, West China Hospital, Sichuan University, No. 37 Guoxue Road, Chengdu, Sichuan 610041, China.
| | - Xiutian Sima
- Department of Neurosurgery, West China Hospital, Sichuan University, Chengdu, Sichuan, China.
| |
Collapse
|
2
|
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: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [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.
Collapse
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
| |
Collapse
|
3
|
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.
Collapse
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.
| |
Collapse
|
4
|
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.
Collapse
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
| | | |
Collapse
|
5
|
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.
Collapse
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
| |
Collapse
|
6
|
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.
Collapse
|
7
|
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.
Collapse
|
8
|
Chorlton SD. Reanalysis of Alzheimer's brain sequencing data reveals absence of purported HHV6A and HHV7. J Bioinform Comput Biol 2021; 18:2050012. [PMID: 32336252 DOI: 10.1142/s0219720020500122] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Readhead et al. recently reported in Neuron the detection and association of human herpesviruses 6A (HHV6A) and 7 (HHV7) with Alzheimer's disease by shotgun sequencing. I was skeptical of the specificity of their modified Viromescan bioinformatics method and subsequent analysis for numerous reasons. Using their supplementary data, the prevalence of variola virus, the etiological agent of the eradicated disease smallpox, can be calculated at 97.5% of their Mount Sinai Brain Bank dataset. Reanalysis of Readhead et al.'s data using highly sensitive and specific alternative methods finds no HHV7 reads in their samples; HHV6A reads were found in only 2 out of their top 15 samples sorted by reported HHV6A abundance. Finally, recreation of Readhead et al.'s modified Viromescan method identifies reasons for its low specificity.
Collapse
Affiliation(s)
- Samuel D Chorlton
- Department of Pathology and Laboratory Medicine, University of British Columbia, Canada
| |
Collapse
|
9
|
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.
Collapse
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
| | | |
Collapse
|
10
|
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: 27] [Impact Index Per Article: 6.8] [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.
Collapse
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
| |
Collapse
|
11
|
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.
Collapse
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
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
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.
Collapse
|
14
|
Figlerowicz M, Mazur-Melewska K, Kemnitz P, Mania A. Pediatric postviral autoimmune disorders of the CNS. Future Virol 2020. [DOI: 10.2217/fvl-2019-0162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Infections caused by various viruses, mainly belonging to the Herpesviridae family, can trigger the autoimmune process in the CNS in children. This can break brain immune tolerance and induce many molecular and cellular pathways of the immune response. This can lead to the appearance of neuronal auto-antibodies to intracellular, cell-surface or extracellular synaptic antigens. Children may also display a wide spectrum of neurological problems from encephalitis to obsessive–compulsive or tic disorders. In these cases, patients rarely respond to traditional treatment, based on antiviral or/and symptomatic drugs, but early immunotherapy is very effective. The implementation of routine immune tests in all children with acute neurological disorders should be recommended.
Collapse
Affiliation(s)
- Magdalena Figlerowicz
- Department of Infectious Diseases & Child Neurology, Karol Marcinkowski University of Medical Sciences, Szpitalna Street 27/33, 60-572 Poznań, Poland
| | - Katarzyna Mazur-Melewska
- Department of Infectious Diseases & Child Neurology, Karol Marcinkowski University of Medical Sciences, Szpitalna Street 27/33, 60-572 Poznań, Poland
| | - Paweł Kemnitz
- Department of Infectious Diseases & Child Neurology, Karol Marcinkowski University of Medical Sciences, Szpitalna Street 27/33, 60-572 Poznań, Poland
| | - Anna Mania
- Department of Infectious Diseases & Child Neurology, Karol Marcinkowski University of Medical Sciences, Szpitalna Street 27/33, 60-572 Poznań, Poland
| |
Collapse
|
15
|
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.
Collapse
|
16
|
Toda J, Maeda T, Akuta K, Kusakabe S, Ueda T, Fujita J, Shibayama H, Oritani K, Takahashi Y, Kanakura Y. Limbic encephalitis with antibodies to N-methyl-d-aspartate (NMDA)-type glutamate receptor after allogeneic transplantation. Int J Hematol 2020; 112:254-257. [DOI: 10.1007/s12185-020-02859-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 03/10/2020] [Accepted: 03/11/2020] [Indexed: 11/29/2022]
|
17
|
Abstract
PURPOSE Human herpesvirus 6 (HHV-6) can infect the central nervous system in immunocompromised individuals. Less is known, however, about HHV-6 infection in immunocompetent patients. This study evaluated the neurologic features and prognosis of HHV-6 infection in immunocompetent patients. METHODS The medical records of patients aged 1 month to 18 years who underwent cerebrospinal fluid examinations and were tested for 6 viruses, including HHV-6, by multiplex polymerase chain reaction were evaluated retrospectively. RESULTS During the study period, 252 children were included. None had underlying disease and all were immunocompetent. Their mean age at diagnosis was 40.98 ± 47.65 months. Of these 252 patients, 144 (57.1%) were diagnosed with meningitis, 84 (33.3%) with febrile seizure not induced by meningitis, and 24 (9.5%) with encephalitis. Of the 9 patients positive for HHV-6, 3 (33.3%) had encephalitis, 3 (33.3%) had meningitis, 1 (11.1%) had complex febrile seizure, and the other 2 patients had fever alone. Outcomes were worse in the seizure group (Fisher exact test, P = .048), especially in patients with status epilepticus (Fisher exact test, P = .012), than in the other groups. Encephalitis patients with and without HHV-6 differed significantly in age (24.0 ± 10.8 vs 63.4 ± 47.7 months, t-test P < .05), with status epilepticus being more frequent in those with HHV-6 (Fisher exact test, P = .010). All 3 encephalitis patients positive for HHV-6 had neurologic sequelae; 2 who had mild sequelae were treated with antiviral agents and intravenous immunoglobulin. CONCLUSIONS HHV-6 may not be completely benign in immunocompetent children. It can be associated with encephalitis and poor prognosis.
Collapse
Affiliation(s)
- Su Jeong You
- Department of Pediatrics, Inje University Sanggye Paik Hospital, Seoul, Korea
| |
Collapse
|
18
|
Lucchese G. Herpesviruses, autoimmunity and epilepsy: Peptide sharing and potential cross-reactivity with human synaptic proteins. Autoimmun Rev 2019; 18:102367. [PMID: 31404705 DOI: 10.1016/j.autrev.2019.102367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 03/22/2019] [Indexed: 12/11/2022]
Abstract
Aggregation of immuno-proteomic data reveals that i) herpesviruses and synaptic proteins -in particular Synapsin-1 and Bassoon - share a large number of hexapeptides that also recur in hundreds of epitopes experimentally validated as immunopositive in the human host, and ii) the shared peptides are also spread among human epilepsy-related proteins. The data indicate that cross-reactive processes may be associated with pathogenetic mechanisms in epilepsy, thus suggesting a role of autoimmunity in etiopathology of epilepsies after herpesvirus-infections.
Collapse
Affiliation(s)
- Guglielmo Lucchese
- University of Greifswald, Department of Neurology, Ferdinand-Sauerbruch-Straße, Greifswald 17495, Germany; Goldsmiths, University of London, Department of Computing, Lewisham Way, New Cross, London SE14 6NW, United Kingdom.
| |
Collapse
|
19
|
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
|
20
|
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
|
21
|
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.
Collapse
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
| |
Collapse
|
22
|
Itzhaki RF. Herpes simplex virus type 1 and Alzheimer's disease: possible mechanisms and signposts. FASEB J 2017; 31:3216-3226. [DOI: 10.1096/fj.201700360] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 04/21/2017] [Indexed: 01/18/2023]
Affiliation(s)
- Ruth F. Itzhaki
- Nuffield Department of Clinical NeurosciencesUniversity of Oxford Oxford United Kingdom
| |
Collapse
|
23
|
|
24
|
Skuja S, Zieda A, Ravina K, Chapenko S, Roga S, Teteris O, Groma V, Murovska M. Structural and Ultrastructural Alterations in Human Olfactory Pathways and Possible Associations with Herpesvirus 6 Infection. PLoS One 2017; 12:e0170071. [PMID: 28072884 PMCID: PMC5224992 DOI: 10.1371/journal.pone.0170071] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 12/28/2016] [Indexed: 12/11/2022] Open
Abstract
Structural and ultrastructural alterations in human olfactory pathways and putative associations with human herpesvirus 6 (HHV-6) infection were studied. The olfactory bulb/tract samples from 20 subjects with an unspecified encephalopathy determined by pathomorphological examination of the brain autopsy, 17 healthy age-matched and 16 younger controls were used. HHV-6 DNA was detected in 60, 29, and 19% of cases in these groups, respectively. In the whole encephalopathy group, significantly more HHV-6 positive neurons and oligodendrocytes were found in the gray matter, whereas, significantly more HHV-6 positive astrocytes, oligodendrocytes, microglia/macrophages and endothelial cells were found in the white matter. Additionally, significantly more HHV-6 positive astrocytes and, in particular, oligodendrocytes were found in the white matter when compared to the gray matter. Furthermore, when only HHV-6 PCR+ encephalopathy cases were studied, we observed similar but stronger associations between HHV-6 positive oligodendrocytes and CD68 positive cells in the white matter. Cellular alterations were additionally evidenced by anti-S100 immunostaining, demonstrating a significantly higher number of S100 positive cells in the gray matter of the whole encephalopathy group when compared to the young controls, and in the white matter when compared to both control groups. In spite the decreased S100 expression in the PCR+ encephalopathy group when compared to PCR- cases and controls, groups demonstrated significantly higher number of S100 positive cells in the white compared to the gray matter. Ultrastructural changes confirming the damage of myelin included irregularity of membranes and ballooning of paranodal loops. This study shows that among the cellular targets of the nervous system, HHV-6 most severely affects oligodendrocytes and the myelin made by them.
Collapse
Affiliation(s)
- Sandra Skuja
- Institute of Anatomy and Anthropology, Riga Stradins University, Riga, Latvia
- * E-mail:
| | - Anete Zieda
- Institute of Anatomy and Anthropology, Riga Stradins University, Riga, Latvia
| | - Kristine Ravina
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, United States of America
| | - Svetlana Chapenko
- A. Kirchenstein Institute of Microbiology and Virology, Riga Stradins University, Riga, Latvia
| | - Silvija Roga
- Department of Pathology, Riga 1st Hospital, Riga, Latvia
| | - Ojars Teteris
- Latvian State Centre for Forensic Medical Examination, Riga, Latvia
| | - Valerija Groma
- Institute of Anatomy and Anthropology, Riga Stradins University, Riga, Latvia
| | - Modra Murovska
- A. Kirchenstein Institute of Microbiology and Virology, Riga Stradins University, Riga, Latvia
| |
Collapse
|
25
|
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: 301] [Impact Index Per Article: 37.6] [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.
Collapse
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.
| |
Collapse
|
26
|
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
| |
Collapse
|
27
|
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.
Collapse
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
| |
Collapse
|
28
|
Sadighi Z, Sabin ND, Hayden R, Stewart E, Pillai A. Diagnostic Clues to Human Herpesvirus 6 Encephalitis and Wernicke Encephalopathy After Pediatric Hematopoietic Cell Transplantation. J Child Neurol 2015; 30:1307-14. [PMID: 25564483 PMCID: PMC4692275 DOI: 10.1177/0883073814560628] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 10/27/2014] [Indexed: 11/17/2022]
Abstract
Human herpesvirus 6 (HHV6) encephalitis and Wernicke encephalopathy are treatable yet frequently undiagnosed causes of encephalopathy in pediatric recipients of allogeneic and autologous hematopoietic cell transplantation. Here we review representative cases of both conditions to highlight specific and relevant neurologic features that prompted effective diagnosis and treatment. Two patients with confusion accompanied by seizures, memory changes, or specific visual hallucinations and HHV6 detectable by polymerase chain reaction (PCR) in cerebrospinal fluid had improvement in viral load with ganciclovir or foscarnet treatment. Two patients had confusion, ataxia, or ocular changes and low serum thiamine levels, which resolved with parenteral thiamine. In all cases, definitive diagnosis and treatment were facilitated by a high index of suspicion and search for specific pathognomonic neurologic deficits accompanying the confusional state. It is critical to clinically differentiate these 2 conditions from other common neurologic syndromes occurring after transplant, allowing potentially improved patient outcomes by prompt diagnosis and effective treatment.
Collapse
Affiliation(s)
- Zsila Sadighi
- Department of Neurology, St Jude Children's Research Hospital, Memphis, TN, USA
| | - Noah D Sabin
- St Jude Children's Research Hospital, Memphis, TN, USA
| | | | | | - Asha Pillai
- Department of Bone Marrow Transplantation and Cellular Therapy, St Jude Children's Research Hospital, Memphis, TN, USA
| |
Collapse
|
29
|
Thom M. Review: Hippocampal sclerosis in epilepsy: a neuropathology review. Neuropathol Appl Neurobiol 2015; 40:520-43. [PMID: 24762203 PMCID: PMC4265206 DOI: 10.1111/nan.12150] [Citation(s) in RCA: 341] [Impact Index Per Article: 37.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 04/23/2014] [Indexed: 12/12/2022]
Abstract
Hippocampal sclerosis (HS) is a common pathology encountered in mesial temporal lobe epilepsy (MTLE) as well as other epilepsy syndromes and in both surgical and post-mortem practice. The 2013 International League Against Epilepsy (ILAE) classification segregates HS into typical (type 1) and atypical (type 2 and 3) groups, based on the histological patterns of subfield neuronal loss and gliosis. In addition, granule cell reorganization and alterations of interneuronal populations, neuropeptide fibre networks and mossy fibre sprouting are distinctive features of HS associated with epilepsies; they can be useful diagnostic aids to discriminate from other causes of HS, as well as highlighting potential mechanisms of hippocampal epileptogenesis. The cause of HS remains elusive and may be multifactorial; the contribution of febrile seizures, genetic susceptibility, inflammatory and neurodevelopmental factors are discussed. Post-mortem based research in HS, as an addition to studies on surgical samples, has the added advantage of enabling the study of the wider network changes associated with HS, the long-term effects of epilepsy on the pathology and associated comorbidities. It is likely that HS is heterogeneous in aspects of its cause, epileptogenetic mechanisms, network alterations and response to medical and surgical treatments. Future neuropathological studies will contribute to better recognition and understanding of these clinical and patho-aetiological subtypes of HS.
Collapse
Affiliation(s)
- Maria Thom
- Departments of Neuropathology and Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, UK
| |
Collapse
|
30
|
Esposito L, Drexler JF, Braganza O, Doberentz E, Grote A, Widman G, Drosten C, Eis-Hübinger AM, Schoch S, Elger CE, Becker AJ, Niehusmann P. Large-scale analysis of viral nucleic acid spectrum in temporal lobe epilepsy biopsies. Epilepsia 2014; 56:234-43. [PMID: 25530314 DOI: 10.1111/epi.12890] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2014] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Chronic inflammatory processes are important promotors of temporal lobe epilepsy (TLE) development. Based on human herpesvirus 6 (HHV-6) DNA detection in brain tissue from patients with TLE, an association of persistent viral infection with TLE has been discussed. Individual studies reported increased HHV-6 DNA in patients with clinical signs of previous inflammatory brain reaction, that is, febrile seizures or meningoencephalitis. However, detection rates vary considerably between different studies. Here we performed a large-scale analysis of viral DNA/RNA spectrum in high-quality TLE biopsies. In addition to all Herpesviridae, we addressed potentially relevant neurotropic RNA viruses. METHODS DNA and RNA were extracted from 346 fresh-frozen tissue samples removed by epilepsy surgery. Real-time polymerase chain reaction (PCR) and nested PCR were performed for Herpesviridae and RNA viruses, respectively. Clinical data were analyzed for earlier signs of inflammatory brain reactions. Fresh-frozen hippocampal tissue samples from patients without chronic central nervous system (CNS) disease served as controls (n = 62). Seven previous PCR studies with overall 178 TLE patients were additionally analyzed regarding a correlation of clinical parameters and HHV-6 detection. RESULTS PCR revealed HHV-6B DNA in 34 specimens (9.8%) from TLE patients. HHV-6B DNA was also present in eight control samples (12.9%; p > 0.05), but showed a lower virus concentration (p < 0.001). Other herpesviruses and RNA viruses were virtually absent. In patients with clinical signs of previous brain inflammation, HHV-6B DNA was observed in 15.0%, whereas only 6.3% of the samples from patients without febrile seizures or meningoencephalitis were positive for HHV-6B DNA (p < 0.05). A meta-analysis of the eight HHV-6 PCR studies revealed similar results. SIGNIFICANCE This biopsy-based study shows no differences in frequency of HHV-6B DNA detection between TLE patients and controls. These results do not support the hypothesis of a persistent HHV-6B infection as a major pathogenetic factor in TLE. However, the higher virus load in TLE patients and the increased detection rate of HHV-6B DNA in patients with previous inflammatory brain reactions require further investigations.
Collapse
Affiliation(s)
- Laura Esposito
- Department of Neuropathology, University of Bonn Medical Center, Bonn, Germany
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Familial or Infectious…or Both? The Complexity of Confirming Causality of Cortical Malformations. Epilepsy Curr 2014; 14:259-60. [PMID: 25346632 DOI: 10.5698/1535-7597-14.5.259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
|
32
|
Tesini BL, Epstein LG, Caserta MT. Clinical impact of primary infection with roseoloviruses. Curr Opin Virol 2014; 9:91-6. [PMID: 25462439 DOI: 10.1016/j.coviro.2014.09.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Revised: 09/17/2014] [Accepted: 09/22/2014] [Indexed: 01/31/2023]
Abstract
The roseoloviruses, human herpesvirus-6A -6B and -7 (HHV-6A, HHV-6B and HHV-7) cause acute infection, establish latency, and in the case of HHV-6A and HHV-6B, whole virus can integrate into the host chromosome. Primary infection with HHV-6B occurs in nearly all children and was first linked to the clinical syndrome roseola infantum. However, roseolovirus infection results in a spectrum of clinical disease, ranging from asymptomatic infection to acute febrile illnesses with severe neurologic complications and accounts for a significant portion of healthcare utilization by young children. Recent advances have underscored the association of HHV-6B and HHV-7 primary infection with febrile status epilepticus as well as the role of reactivation of latent infection in encephalitis following cord blood stem cell transplantation.
Collapse
Affiliation(s)
- Brenda L Tesini
- Division of Infectious Diseases, Department of Pediatrics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Box 690, Rochester, NY 14642, USA
| | - Leon G Epstein
- Departments of Pediatrics and Neurology, Feinberg School of Medicine, Northwestern University and the Ann & Robert H. Lurie Children's Hospital of Chicago, Box 51, 225 E Chicago Ave, Chicago, IL 60611, USA
| | - Mary T Caserta
- Division of Infectious Diseases, Department of Pediatrics, University of Rochester School of Medicine and Dentistry, 601 Elmwood Ave, Box 690, Rochester, NY 14642, USA.
| |
Collapse
|
33
|
Abstract
Few would experience greater benefit from the development of biomarkers than those who suffer from epilepsy. Both the timing of individual seizures and the overall course of the disease are highly unpredictable, and the associated morbidity is considerable. Thus, there is an urgent need to develop biomarkers that can predict the progression of epilepsy and treatment response. Doing so may also shed light on the mechanisms of epileptogenesis and pharmacoresistance, which remain elusive despite decades of study. However, recent advances suggest the possible identification of circulating epilepsy biomarkers – accessible in blood, cerebrospinal fluid or urine. In this review, we focus on advances in several areas: neuroimmunology and inflammation; neurological viral infection; exemplary pediatric syndromes; and the genetics of pharmacoresistance, as relevant to epilepsy. These are fertile areas of study with great potential to yield accessible epilepsy biomarkers.
Collapse
Affiliation(s)
- Manu Hegde
- UCSF Epilepsy Center, Department of Neurology, University of California, San Francisco, 521 Parnassus Avenue C-440, San Francisco, CA 94143-0138, USA
- Epilepsy Center of Excellence, San Francisco Veterans Affairs Medical Center, 4150 Clement Street, 127E, San Francisco, CA 94121, USA
| | - Daniel H Lowenstein
- UCSF Epilepsy Center, Department of Neurology, University of California, San Francisco, 521 Parnassus Avenue C-440, San Francisco, CA 94143-0138, USA
| |
Collapse
|
34
|
Houenou J, d'Albis MA, Daban C, Hamdani N, Delavest M, Lepine JP, Vederine FE, Carde S, Lajnef M, Cabon C, Dickerson F, Yolken RH, Tamouza R, Poupon C, Leboyer M. Cytomegalovirus seropositivity and serointensity are associated with hippocampal volume and verbal memory in schizophrenia and bipolar disorder. Prog Neuropsychopharmacol Biol Psychiatry 2014; 48:142-8. [PMID: 24083998 DOI: 10.1016/j.pnpbp.2013.09.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 08/27/2013] [Accepted: 09/07/2013] [Indexed: 12/21/2022]
Abstract
INTRODUCTION Cytomegalovirus (CMV) is a member of the herpesviridae family that has a limbic and temporal gray matter tropism. It is usually latent in humans but has been associated with schizophrenia, bipolar disorder and cognitive deficits in some populations. Hippocampal decreased volume and dysfunction play a critical role in these cognitive deficits. We hypothesized that CMV seropositivity and serointensity would be associated with hippocampal volume and cognitive functioning in patients with schizophrenia or bipolar disorder. METHODS 102 healthy controls, 118 patients with bipolar disorder and 69 patients with schizophrenia performed the California Verbal Learning Test (CVLT) and had blood samples drawn to assess CMV IgG levels. A subgroup of 52 healthy controls, 31 patients with bipolar disorder and 27 patients with schizophrenia underwent T1 MRI for hippocampal volumetry. We analyzed the association between CMV serointensity and seropositivity with hippocampal volume. We also explored the correlation between CMV serointensity and seropositivity and CVLT scores. RESULTS In both patient groups but not in controls, higher CMV serointensity was significantly associated with smaller right hippocampal volume. Further, in the group of patients with schizophrenia but not bipolar disorder, CMV serointensity was negatively correlated with CVLT scores. CONCLUSION CMV IgG titers are associated with decreased hippocampal volume and poorer episodic verbal memory in patients with schizophrenia or bipolar disorder. The mechanism of this association warrants further exploration.
Collapse
Affiliation(s)
- J Houenou
- INSERM, U955, Equipe 15 "Psychiatrie Génétique", Créteil F-94000, France; Fondation Fondamental, Créteil F-94010, France; AP-HP, Groupe Henri Mondor - Albert Chenevier, Pôle de Psychiatrie, Créteil, F-94000, France; Neurospin, CEA Saclay, Gif-Sur-Yvette, France.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
35
|
Immunotherapeutic strategies to prevent and treat human herpesvirus 6 reactivation after allogeneic stem cell transplantation. Blood 2012; 121:207-18. [PMID: 23152545 DOI: 10.1182/blood-2012-05-430413] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Human herpesvirus (HHV) 6 causes substantial morbidity and mortality in the immunocompromised host and has no approved therapy. Adoptive transfer of virus specific T cells has proven safe and apparently effective as prophylaxis and treatment of other virus infections in immunocompromised patients; however, extension to subjects with HHV6 has been hindered by the paucity of information on targets of cellular immunity. We now characterize the cellular immune response from 20 donors against 5 major HHV6B antigens predicted to be immunogenic and define a hierarchy of immunodominance of antigens based on the frequency of responding donors and the magnitude of the T-cell response. We identified specific epitopes within these antigens and expanded the HHV6 reactive T cells using a GMP-compliant protocol. The expanded population comprised both CD4(+) and CD8(+) T cells that were able to produce multiple effector cytokines and kill both peptide-loaded and HHV6B wild-type virus-infected target cells. Thus, we conclude that adoptive T-cell immunotherapy for HHV6 is a practical objective and that the peptide and epitope tools we describe will allow such cells to be prepared, administered, and monitored in human subjects.
Collapse
|
36
|
Natural history of temporal lobe epilepsy: antecedents and progression. EPILEPSY RESEARCH AND TREATMENT 2012; 2012:195073. [PMID: 22937237 PMCID: PMC3420774 DOI: 10.1155/2012/195073] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 12/20/2011] [Accepted: 12/29/2011] [Indexed: 11/17/2022]
Abstract
Temporal lobe epilepsy represents the largest group of patients with treatment resistant/medically intractable epilepsy undergoing epilepsy surgery. The underpinnings of common forms of TLE in many instances begin in early life with the occurrence of an initial precipitating event. The first epileptic seizure often occurs after a variable latency period following this event. The precise natural history and progression following the first seizure to the development of TLE, its subsequent resolution through spontaneous remission or the development of treatment resistant epilepsy remain poorly understood. Our present understanding of the role played by these initial events, the subsequent latency to development of temporal lobe epilepsy, and the emergence of treatment resistance remains incomplete. A critical analysis of published data suggest that TLE is a heterogeneous condition, where the age of onset, presence or absence of a lesion on neuroimaging, the initial precipitating event, association with febrile seizures, febrile status epilepticus, and neurotropic viral infections influence the natural history and outcome. The pathways and processes through which these variables coalesce into a framework will provide the basis for an understanding of the natural history of TLE. The questions raised need to be addressed in future prospective and longitudinal observational studies.
Collapse
|
37
|
Gu B, Zhang GF, Li LY, Zhou F, Feng DJ, Ding CL, Chi J, Zhang C, Guo DD, Wang JF, Zhou H, Yao K, Hu WX. Human herpesvirus 6A induces apoptosis of primary human fetal astrocytes via both caspase-dependent and -independent pathways. Virol J 2011; 8:530. [PMID: 22152093 PMCID: PMC3253131 DOI: 10.1186/1743-422x-8-530] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Accepted: 12/12/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Human herpesvirus 6 (HHV-6) is a T-lymphtropic and neurotropic virus that can infect various types of cells. Sequential studies reported that apoptosis of glia and neurons induced by HHV-6 might act a potential trigger for some central nervous system (CNS) diseases. HHV-6 is involved in the pathogenesis of encephalitis, multiple sclerosis (MS) and fatigue syndrome. However, the mechanisms responsible for the apoptosis of infected CNS cells induced by HHV-6 are poorly understood. In this study, we investigated the cell death processes of primary human fetal astrocytes (PHFAs) during productive HHV-6A infection and the underlying mechanisms. RESULTS HHV-6A can cause productive infection in primary human fetal astrocytes. Annexin V-PI staining and electron microscopic analysis indicated that HHV-6A was an inducer of apoptosis. The cell death was associated with activation of caspase-3 and cleavage of poly (ADP-ribose) polymerase (PARP), which is known to be an important substrate for activated caspase-3. Caspase-8 and -9 were also significantly activated in HHV-6A-infected cells. Moreover, HHV-6A infection led to Bax up-regulation and Bcl-2 down-regulation. HHV-6A infection increased the release of Smac/Diablo, AIF and cytochrome c from mitochondria to cytosol, which induced apoptosis via the caspase-dependent and -independent pathways. In addition, we also found that anti-apoptotic factors such as IAPs and NF-κB decreased in HHV-6A infected PHFAs. CONCLUSION This is the first demonstration of caspase-dependent and -independent apoptosis in HHV-6A-infected glial cells. These findings would be helpful in understanding the mechanisms of CNS diseases caused by HHV-6.
Collapse
Affiliation(s)
- Bin Gu
- Department of Neurosurgery, First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, China
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Libbey JE, Fujinami RS. Neurotropic viral infections leading to epilepsy: focus on Theiler's murine encephalomyelitis virus. Future Virol 2011; 6:1339-1350. [PMID: 22267964 PMCID: PMC3259611 DOI: 10.2217/fvl.11.107] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Neurotropic viruses cause viral encephalitis and are associated with the development of seizures/epilepsy. The first infection-driven animal model for epilepsy, the Theiler's murine encephalomyelitis virus-induced seizure model is described herein. Intracerebral infection of C57BL/6 mice with Theiler's murine encephalomyelitis virus induces acute seizures from which the animals recover. However, once the virus is cleared, a significant portion of the animals that experienced acute seizures later develop epilepsy. Components of the innate immune response to viral infection, including IL-6 and complement component 3, have been implicated in the development of acute seizures. Multiple mechanisms, including neuronal cell destruction and cytokine activation, play a role in the development of acute seizures. Future studies targeting the innate immune response will lead to new therapies for seizures/epilepsy.
Collapse
Affiliation(s)
- Jane E Libbey
- Department of Pathology, University of Utah, 30 North 1900 East, 3R330 SOM, Salt Lake City, UT 84132, USA
| | - Robert S Fujinami
- Department of Pathology, University of Utah, 30 North 1900 East, 3R330 SOM, Salt Lake City, UT 84132, USA
| |
Collapse
|