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Flace P, Galletta D, Bizzoca A, Gennarini G, Livrea P. A candidate projective neuron type of the cerebellar cortex: the synarmotic neuron. Eur J Histochem 2024; 68:3954. [PMID: 38766720 PMCID: PMC11148694 DOI: 10.4081/ejh.2024.3954] [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: 12/29/2023] [Accepted: 04/20/2024] [Indexed: 05/22/2024] Open
Abstract
Previous studies on the granular layer of the cerebellar cortex have revealed a wide distribution of different subpopulations of less-known large neuron types, called "non-traditional large neurons", which are distributed in three different zones of the granular layer. These neuron types are mainly involved in the formation of intrinsiccircuits inside the cerebellar cortex. A subpopulation of these neuron types is represented by the synarmotic neuron, which could play a projective role within the cerebellar circuitry. The synarmotic neuron cell body map within the internal zone of the granular layer or in the subjacent white substance. Furthermore, the axon crosses the granular layer and runs in the subcortical white substance, to reenter in an adjacent granular layer, associating two cortico-cerebellar regions of the same folium or of different folia, or could project to the intrinsic cerebellar nuclei. Therefore, along with the Purkinje neuron, the traditional projective neuron type of the cerebellar cortex, the synarmotic neuron is candidate to represent the second projective neuron type of the cerebellar cortex. Studies of chemical neuroanatomy evidenced a predominant inhibitory GABAergic nature of the synarmotic neuron, suggesting that it may mediate an inhibitory GABAergic output of cerebellar cortex within cortico-cortical interconnections or in projections towards intrinsic cerebellar nuclei. On this basis, the present minireview mainly focuses on the morphofunctional and neurochemical data of the synarmotic neuron, and explores its potential involvement in some forms of cerebellar ataxias.
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Affiliation(s)
- Paolo Flace
- Medical School, University of Bari Aldo Moro, Bari.
| | - Diana Galletta
- Unit of Psychiatry and Psychology, Federico II University Hospital, Naples.
| | - Antonella Bizzoca
- Department of Translational Biomedicine and Neuroscience "DiBraiN", University of Bari Aldo Moro, Bari.
| | - Gianfranco Gennarini
- Department of Translational Biomedicine and Neuroscience "DiBraiN", University of Bari Aldo Moro, Bari.
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2
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Mitoma H, Manto M. Advances in the Pathogenesis of Auto-antibody-Induced Cerebellar Synaptopathies. CEREBELLUM (LONDON, ENGLAND) 2023; 22:129-147. [PMID: 35064896 PMCID: PMC9883363 DOI: 10.1007/s12311-021-01359-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Accepted: 12/12/2021] [Indexed: 02/07/2023]
Abstract
The presence of auto-antibodies that target synaptic machinery proteins was documented recently in immune-mediated cerebellar ataxias. The autoantigens include glutamic acid decarboxylase 65 (GAD65), voltage-gated Ca2+ channel (VGCC), metabotropic glutamate receptor type 1 (mGluR1), and glutamate receptor delta (GluRdelta). GAD65 is involved in the synthesis, packaging, and release of GABA, whereas the other three play important roles in the induction of long-term depression (LTD). Thus, the auto-antibodies toward these synaptic molecules likely impair fundamental synaptic machineries involved in unique functions of the cerebellum, potentially leading to the development of cerebellar ataxias (CAs). This concept has been substantiated recently by a series of physiological studies. Anti-GAD65 antibody (Ab) acts on the terminals of inhibitory neurons that suppress GABA release, whereas anti-VGCC, anti-mGluR1, and anti-GluR Abs impair LTD induction. Notably, the mechanisms that link synaptic dysfunction with the manifestations of CAs can be explained by disruption of the "internal models." The latter can be divided into three levels. First, since chained inhibitory neurons shape the output signals through the mechanism of disinhibition/inhibition, impairments of GABA release and LTD distort the conversion process from the "internal model" to the output signals. Second, these antibodies impair the induction of synaptic plasticity, rebound potentiation, and LTD, on Purkinje cells, resulting in loss of restoration and compensation of the distorted "internal models." Finally, the cross-talk between glutamate and microglia/astrocytes could involve a positive feedback loop that accelerates excitotoxicity. This mini-review summarizes the pathophysiological mechanisms and aims to establish the basis of "auto-antibody-induced cerebellar synaptopathies."
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Affiliation(s)
- Hiroshi Mitoma
- Department of Medical Education, Tokyo Medical University, Tokyo, Japan
| | - Mario Manto
- Unité des Ataxies Cérébelleuses, Service de Neurologie, Médiathèque Jean Jacquy, CHU-Charleroi, 6000 Charleroi, Belgium ,Service des Neurosciences, University of Mons, 7000 Mons, Belgium
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3
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Hampe CS, Mitoma H. A Breakdown of Immune Tolerance in the Cerebellum. Brain Sci 2022; 12:brainsci12030328. [PMID: 35326284 PMCID: PMC8946792 DOI: 10.3390/brainsci12030328] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/22/2022] [Accepted: 02/25/2022] [Indexed: 11/21/2022] Open
Abstract
Cerebellar dysfunction can be associated with ataxia, dysarthria, dysmetria, nystagmus and cognitive deficits. While cerebellar dysfunction can be caused by vascular, traumatic, metabolic, genetic, inflammatory, infectious, and neoplastic events, the cerebellum is also a frequent target of autoimmune attacks. The underlying cause for this vulnerability is unclear, but it may be a result of region-specific differences in blood–brain barrier permeability, the high concentration of neurons in the cerebellum and the presence of autoantigens on Purkinje cells. An autoimmune response targeting the cerebellum—or any structure in the CNS—is typically accompanied by an influx of peripheral immune cells to the brain. Under healthy conditions, the brain is protected from the periphery by the blood–brain barrier, blood–CSF barrier, and blood–leptomeningeal barrier. Entry of immune cells to the brain for immune surveillance occurs only at the blood-CSF barrier and is strictly controlled. A breakdown in the barrier permeability allows peripheral immune cells uncontrolled access to the CNS. Often—particularly in infectious diseases—the autoimmune response develops because of molecular mimicry between the trigger and a host protein. In this review, we discuss the immune surveillance of the CNS in health and disease and also discuss specific examples of autoimmunity affecting the cerebellum.
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Affiliation(s)
- Christiane S. Hampe
- Department of Medicine, University of Washington, Seattle, WA 98195, USA
- Correspondence: ; Tel.: +1-206-554-9181
| | - Hiroshi Mitoma
- Department of Medical Education, Tokyo Medical University, Tokyo 160-0023, Japan;
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4
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Tsiortou P, Alexopoulos H, Dalakas MC. GAD antibody-spectrum disorders: progress in clinical phenotypes, immunopathogenesis and therapeutic interventions. Ther Adv Neurol Disord 2021; 14:17562864211003486. [PMID: 33854562 PMCID: PMC8013924 DOI: 10.1177/17562864211003486] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 02/27/2021] [Indexed: 12/14/2022] Open
Abstract
Antibodies against glutamic acid decarboxylase (GAD), originally linked to stiff person syndrome (SPS), now denote the "GAD antibody-spectrum disorders" (GAD-SD) that also include autoimmune epilepsy, limbic encephalitis, cerebellar ataxia and nystagmus with overlapping symptomatology highlighting autoimmune neuronal excitability disorders. The reasons for the clinical heterogeneity among GAD-antibody associated syndromes remain still unsettled, implicating variable susceptibility of GABAergic neurons to anti-GAD or other still unidentified autoantibodies. Although anti-GAD antibody titers do not correlate with clinical severity, very high serum titers, often associated with intrathecal synthesis of anti-GAD-specific IgG, point to in-situ effects of GAD or related autoantibodies within the central nervous system. It remains, however, uncertain what drives these antibodies, why they persist and whether they are disease markers or have pathogenic potential. The review, focused on these concerns, describes the widened clinical manifestations and overlapping features of all GAD-SD; addresses the importance of GAD antibody titers and potential significance of GAD epitopes; summarizes the biologic basis of autoimmune hyperexcitability; highlights the electrophysiological basis of reciprocal inhibition in muscle stiffness; and provides practical guidelines on symptomatic therapies with gamma-aminobutyric acid-enhancing drugs or various immunotherapies.
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Affiliation(s)
- Popianna Tsiortou
- Neuroimmunology Unit, Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Harry Alexopoulos
- Neuroimmunology Unit, Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Marinos C Dalakas
- Department of Neurology, Thomas Jefferson University, 900 Walnut Street, Philadelphia, PA 19107, USA; Neuroimmunology Unit, National and Kapodistrian University of Athens, Athens, Greece
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5
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Mitoma H, Manto M, Hadjivassiliou M. Immune-Mediated Cerebellar Ataxias: Clinical Diagnosis and Treatment Based on Immunological and Physiological Mechanisms. J Mov Disord 2021; 14:10-28. [PMID: 33423437 PMCID: PMC7840241 DOI: 10.14802/jmd.20040] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 09/04/2020] [Indexed: 12/24/2022] Open
Abstract
Since the first description of immune-mediated cerebellar ataxias (IMCAs) by Charcot in 1868, several milestones have been reached in our understanding of this group of neurological disorders. IMCAs have diverse etiologies, such as gluten ataxia, postinfectious cerebellitis, paraneoplastic cerebellar degeneration, opsoclonus myoclonus syndrome, anti-GAD ataxia, and primary autoimmune cerebellar ataxia. The cerebellum, a vulnerable autoimmune target of the nervous system, has remarkable capacities (collectively known as the cerebellar reserve, closely linked to plasticity) to compensate and restore function following various pathological insults. Therefore, good prognosis is expected when immune-mediated therapeutic interventions are delivered during early stages when the cerebellar reserve can be preserved. However, some types of IMCAs show poor responses to immunotherapies, even if such therapies are introduced at an early stage. Thus, further research is needed to enhance our understanding of the autoimmune mechanisms underlying IMCAs, as such research could potentially lead to the development of more effective immunotherapies. We underscore the need to pursue the identification of robust biomarkers.
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Affiliation(s)
- Hiroshi Mitoma
- Department of Medical Education, Tokyo Medical University, Tokyo, Japan
| | - Mario Manto
- Service de Neurologie, Médiathèque Jean Jacquy, CHU-Charleroi, Charleroi, Belgium.,Service des Neurosciences, University of Mons, Mons, Belgium
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Fundamental Mechanisms of Autoantibody-Induced Impairments on Ion Channels and Synapses in Immune-Mediated Cerebellar Ataxias. Int J Mol Sci 2020; 21:ijms21144936. [PMID: 32668612 PMCID: PMC7404345 DOI: 10.3390/ijms21144936] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/07/2020] [Accepted: 07/09/2020] [Indexed: 12/13/2022] Open
Abstract
In the last years, different kinds of limbic encephalitis associated with autoantibodies against ion channels and synaptic receptors have been described. Many studies have demonstrated that such autoantibodies induce channel or receptor dysfunction. The same mechanism is discussed in immune-mediated cerebellar ataxias (IMCAs), but the pathogenesis has been less investigated. The aim of the present review is to evaluate what kind of cerebellar ion channels, their related proteins, and the synaptic machinery proteins that are preferably impaired by autoantibodies so as to develop cerebellar ataxias (CAs). The cerebellum predictively coordinates motor and cognitive functions through a continuous update of an internal model. These controls are relayed by cerebellum-specific functions such as precise neuronal discharges with potassium channels, synaptic plasticity through calcium signaling pathways coupled with voltage-gated calcium channels (VGCC) and metabotropic glutamate receptors 1 (mGluR1), a synaptic organization with glutamate receptor delta (GluRδ), and output signal formation through chained GABAergic neurons. Consistently, the association of CAs with anti-potassium channel-related proteins, anti-VGCC, anti-mGluR1, and GluRδ, and anti-glutamate decarboxylase 65 antibodies is observed in IMCAs. Despite ample distributions of AMPA and GABA receptors, however, CAs are rare in conditions with autoantibodies against these receptors. Notably, when the autoantibodies impair synaptic transmission, the autoimmune targets are commonly classified into three categories: release machinery proteins, synaptic adhesion molecules, and receptors. This physiopathological categorization impacts on both our understanding of the pathophysiology and clinical prognosis.
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7
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Isern de Val Í, Gazulla J. Myoclonus-dystonia and cerebellar ataxia in association with anti-glutamic acid decarboxylase autoimmunity. NEUROLOGÍA (ENGLISH EDITION) 2020. [DOI: 10.1016/j.nrleng.2018.05.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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8
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Isern de Val Í, Gazulla J. Distonía mioclónica y ataxia cerebelosa en la autoinmunidad antiglutámico-descarboxilasa. Neurologia 2020; 35:423-425. [DOI: 10.1016/j.nrl.2018.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 05/23/2018] [Accepted: 05/27/2018] [Indexed: 11/29/2022] Open
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Dade M, Berzero G, Izquierdo C, Giry M, Benazra M, Delattre JY, Psimaras D, Alentorn A. Neurological Syndromes Associated with Anti-GAD Antibodies. Int J Mol Sci 2020; 21:E3701. [PMID: 32456344 PMCID: PMC7279468 DOI: 10.3390/ijms21103701] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/19/2020] [Accepted: 05/21/2020] [Indexed: 12/11/2022] Open
Abstract
Glutamic acid decarboxylase (GAD) is an intracellular enzyme whose physiologic function is the decarboxylation of glutamate to gamma-aminobutyric acid (GABA), the main inhibitory neurotransmitter within the central nervous system. GAD antibodies (Ab) have been associated with multiple neurological syndromes, including stiff-person syndrome, cerebellar ataxia, and limbic encephalitis, which are all considered to result from reduced GABAergic transmission. The pathogenic role of GAD Ab is still debated, and some evidence suggests that GAD autoimmunity might primarily be cell-mediated. Diagnosis relies on the detection of high titers of GAD Ab in serum and/or in the detection of GAD Ab in the cerebrospinal fluid. Due to the relative rarity of these syndromes, treatment schemes and predictors of response are poorly defined, highlighting the unmet need for multicentric prospective trials in this population. Here, we reviewed the main clinical characteristics of neurological syndromes associated with GAD Ab, focusing on pathophysiologic mechanisms.
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Affiliation(s)
- Maëlle Dade
- AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Service de Neurologie 2-Mazarin, 75013 Paris, France; (M.D.); (G.B.); (J.-Y.D.); (D.P.)
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, 75013 Paris, France; (M.G.); (M.B.)
| | - Giulia Berzero
- AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Service de Neurologie 2-Mazarin, 75013 Paris, France; (M.D.); (G.B.); (J.-Y.D.); (D.P.)
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, 75013 Paris, France; (M.G.); (M.B.)
- Neuroncology Unit, IRCCS Mondino Foundation, 27100 Pavia, Italy
| | - Cristina Izquierdo
- Department of Neuroscience, Hospital Universitari Germans Trias i Pujol, Universitat Autònoma de Barcelona, 08916 Badalona, Spain;
| | - Marine Giry
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, 75013 Paris, France; (M.G.); (M.B.)
| | - Marion Benazra
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, 75013 Paris, France; (M.G.); (M.B.)
| | - Jean-Yves Delattre
- AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Service de Neurologie 2-Mazarin, 75013 Paris, France; (M.D.); (G.B.); (J.-Y.D.); (D.P.)
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, 75013 Paris, France; (M.G.); (M.B.)
| | - Dimitri Psimaras
- AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Service de Neurologie 2-Mazarin, 75013 Paris, France; (M.D.); (G.B.); (J.-Y.D.); (D.P.)
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, 75013 Paris, France; (M.G.); (M.B.)
| | - Agusti Alentorn
- AP-HP, Groupe Hospitalier Pitié-Salpêtrière, Service de Neurologie 2-Mazarin, 75013 Paris, France; (M.D.); (G.B.); (J.-Y.D.); (D.P.)
- Sorbonne Université, Inserm, CNRS, UMR S 1127, Institut du Cerveau et de la Moelle épinière, ICM, 75013 Paris, France; (M.G.); (M.B.)
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10
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Immune-mediated epilepsy with GAD65 antibodies. J Neuroimmunol 2020; 341:577189. [PMID: 32087461 DOI: 10.1016/j.jneuroim.2020.577189] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 02/11/2020] [Accepted: 02/11/2020] [Indexed: 12/18/2022]
Abstract
Anti-GAD65 antibodies have been identified in both acute/subacute seizures (limbic encephalitis and extralimbic encephalitis) and chronic isolated epilepsy. The evidence of high serum titers and intrathecal synthesis play a fundamental role in diagnosis but poorly correlate with disease severity or response to therapies. It remains controversial whether anti-GAD65 Abs are the pathogenic entity or only serve as a surrogate marker for autoimmune disorders mediated by cytotoxic T cells. Unlike other immune-mediated epilepsy, although multiple combinations of therapeutics are used, the efficacy and prognosis of patients with GAD65-epilepsy patients are poor. Besides, GAD65-epilepsy is more prone to relapse and potentially evolve into a more widespread CNS inflammatory disorder. This article reviews the recent advances of GAD65-epilepsy, focusing on the diagnosis, epidemiology, pathophysiology, clinical features, and treatment, to better promote the recognition and provide proper therapy for this condition.
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Manto M, Mitoma H, Hampe CS. Anti-GAD Antibodies and the Cerebellum: Where Do We Stand? THE CEREBELLUM 2019; 18:153-156. [PMID: 30343467 PMCID: PMC6443918 DOI: 10.1007/s12311-018-0986-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Anti-GAD65 antibodies (anti-GAD65 Abs) are associated with cerebellar ataxia (CA). The significance of anti-GAD65 Abs has been a focus of debates. Since GAD65 is intracellularly located and associated with type 1 diabetes mellitus and different clinical neurological phenotypes such as CA, stiff-person syndrome, and epilepsy, some researchers have argued that anti-GAD65 Abs have no pathogenic roles. On the other hand, recent physiological studies in vitro and in vivo have elucidated that binding of GAD65 by anti-GAD65 Abs elicits loss of GAD65 functions pertaining GABA release with an epitope dependence, leading to the development of CA. Internalization of autoantibodies has been also clarified. These studies provide substantial evidence of the pathogenesis of anti-GAD65 Abs in CA. We also discuss methodological problems in the identification of anti-GAD65 Abs.
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Affiliation(s)
- Mario Manto
- Service de Neurologie, Médiathèque Jean Jacquy, CHU-Charleroi, 6000, Charleroi, Belgium.,Service des Neurosciences, University of Mons, 7000, Mons, Belgium
| | - Hiroshi Mitoma
- Medical Education Promotion Center, Tokyo Medical University, Tokyo, Japan.
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Kakei S, Ishikawa T, Lee J, Honda T, Hoffman DS. Physiological and Morphological Principles Underpinning Recruitment of the Cerebellar Reserve. CNS & NEUROLOGICAL DISORDERS-DRUG TARGETS 2019; 17:184-192. [PMID: 29546837 PMCID: PMC6142411 DOI: 10.2174/1871527317666180315164429] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 12/25/2017] [Accepted: 12/27/2017] [Indexed: 12/05/2022]
Abstract
Background: In order to optimize outcomes of novel therapies for cerebellar ataxias (CAs), it is desirable to start these therapies while declined functions are restorable: i.e. while the so-called cere-bellar reserve remains. Objective: In this mini-review, we tried to define and discuss the cerebellar reserve from physiological and morphological points of view. Method: The cerebellar neuron circuitry is designed to generate spatiotemporally organized outputs, re-gardless of the region. Therefore, the cerebellar reserve may be defined as a mechanism to restore its proper input-output organization of the cerebellar neuron circuitry, when it is damaged. Then, the follow-ing four components are essential for recruitment of the cerebellar reserve: operational local neuron cir-cuitry; proper combination of mossy fiber inputs to be integrated; climbing fiber inputs to instruct favor-able reorganization of the integration; deep cerebellar nuclei to generate reorganized outputs. Results: We discussed three topics related to these resources, 1) principles of generating organized cere-bellar outputs, 2) redundant mossy fiber inputs to the cerebellum, 3) plasticity of the cerebellar neuron circuitry. Conclusion: To make most of the cerebellar reserve, it is desirable to start any intervention as early as possible when the cerebellar cell loss is minimal or even negligible. Therefore, an ideal future therapy for degenerative cerebellar diseases should start before consuming the cerebellar reserve at all. In the meantime, our real challenge is to establish a reliable method to identify the decrease in the cerebellar re-serve as early as possible.
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Affiliation(s)
- Shinji Kakei
- Movement Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Takahiro Ishikawa
- Movement Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Jongho Lee
- Movement Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Takeru Honda
- Movement Disorders Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Donna S Hoffman
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, United States.,Center for the Neural Basis of Cognition, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, United States
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Mitoma H, Manto M, Hampe CS. Immune-mediated Cerebellar Ataxias: Practical Guidelines and Therapeutic Challenges. Curr Neuropharmacol 2019; 17:33-58. [PMID: 30221603 PMCID: PMC6341499 DOI: 10.2174/1570159x16666180917105033] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 07/06/2018] [Accepted: 09/03/2018] [Indexed: 12/11/2022] Open
Abstract
Immune-mediated cerebellar ataxias (IMCAs), a clinical entity reported for the first time in the 1980s, include gluten ataxia (GA), paraneoplastic cerebellar degenerations (PCDs), antiglutamate decarboxylase 65 (GAD) antibody-associated cerebellar ataxia, post-infectious cerebellitis, and opsoclonus myoclonus syndrome (OMS). These IMCAs share common features with regard to therapeutic approaches. When certain factors trigger immune processes, elimination of the antigen( s) becomes a priority: e.g., gluten-free diet in GA and surgical excision of the primary tumor in PCDs. Furthermore, various immunotherapeutic modalities (e.g., steroids, immunoglobulins, plasmapheresis, immunosuppressants, rituximab) should be considered alone or in combination to prevent the progression of the IMCAs. There is no evidence of significant differences in terms of response and prognosis among the various types of immunotherapies. Treatment introduced at an early stage, when CAs or cerebellar atrophy is mild, is associated with better prognosis. Preservation of the "cerebellar reserve" is necessary for the improvement of CAs and resilience of the cerebellar networks. In this regard, we emphasize the therapeutic principle of "Time is Cerebellum" in IMCAs.
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Affiliation(s)
- Hiroshi Mitoma
- Address correspondence to this author at the Medical Education Promotion Center, Tokyo Medical University, Tokyo, Japan;, E-mail:
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Nakamura Y, Nakajima H, Hosokawa T, Yamane K, Ishida S, Kimura F. Acute Cerebellar Ataxia Associated with Anti-glutamic Acid Decarboxylase Antibodies Mimicking Miller Fisher Syndrome. Intern Med 2018; 57:269-271. [PMID: 29093402 PMCID: PMC5820049 DOI: 10.2169/internalmedicine.9190-17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We herein report the case of a 53-year-old man with cerebellar ataxia with anti-glutamic acid decarboxylase antibody (GAD-Ab) who mimicked Miller Fisher syndrome (MFS). He developed ophthalmoplegia, diplopia, and gait ataxia for one week. The serum and cerebrospinal fluid GAD-Ab titers were greatly increased, and the GAD-Ab index suggesting intrathecal antibody synthesis was elevated, while GQ1b-Ab was negative. After steroid pulse therapy and following prednisolone, his symptoms dramatically improved over the course of 11 months with the simultaneous decline of GAD-Ab titers. This case indicates that cerebellar ataxia with GAD-Ab can present with acute neurological findings mimicking MFS, and that steroid therapy has an excellent therapeutic effect.
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Affiliation(s)
- Yoshitsugu Nakamura
- Division of Neurology, Department of Internal Medicine IV, Osaka Medical College, Japan
| | - Hideto Nakajima
- Division of Neurology, Department of Internal Medicine IV, Osaka Medical College, Japan
| | - Takafumi Hosokawa
- Division of Neurology, Department of Internal Medicine IV, Osaka Medical College, Japan
| | - Kazushi Yamane
- Division of Neurology, Department of Internal Medicine IV, Osaka Medical College, Japan
| | - Shimon Ishida
- Division of Neurology, Department of Internal Medicine IV, Osaka Medical College, Japan
| | - Fumiharu Kimura
- Division of Neurology, Department of Internal Medicine IV, Osaka Medical College, Japan
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15
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Mitoma H, Manto M, Hampe CS. Immune-mediated cerebellar ataxias: from bench to bedside. CEREBELLUM & ATAXIAS 2017; 4:16. [PMID: 28944066 PMCID: PMC5609024 DOI: 10.1186/s40673-017-0073-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Accepted: 09/07/2017] [Indexed: 02/08/2023]
Abstract
The cerebellum is a vulnerable target of autoimmunity in the CNS. The category of immune-mediated cerebellar ataxias (IMCAs) was recently established, and includes in particular paraneoplastic cerebellar degenerations (PCDs), gluten ataxia (GA) and anti-GAD65 antibody (Ab) associated-CA, all characterized by the presence of autoantibodies. The significance of onconeuronal autoantibodies remains uncertain in some cases. The pathogenic role of anti-GAD65Ab has been established both in vitro and in vivo, but a consensus has not been reached yet. Recent studies of anti-GAD65 Ab-associated CA have clarified that (1) autoantibodies are generally polyclonal and elicit pathogenic effects related to epitope specificity, and (2) the clinical course can be divided into two phases: a phase of functional disorder followed by cell death. These features provide the rationale for prompt diagnosis and therapeutic strategies. The concept “Time is brain” has been completely underestimated in the field of immune ataxias. We now put forward the concept “Time is cerebellum” to underline the importance of very early therapeutic strategies in order to prevent or stop the loss of neurons and synapses. The diagnosis of IMCAs should depend not only on Ab testing, but rather on a rapid and comprehensive assessment of the clinical/immune profile. Treatment should be applied during the period of preserved cerebellar reserve, and should encompass early removal of the conditions (such as remote primary tumors) or diseases that trigger the autoimmunity, followed by the combinations of various immunotherapies.
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Affiliation(s)
- Hiroshi Mitoma
- Tokyo Medical University, Medical Education Promotion Center, 6-7-1 Nishi-Shinjyuku, Shinjyuku-ku, Tokyo, 160-0023 Japan
| | - Mario Manto
- Unité d'Etude du Mouvement (UEM), FNRS, ULB-Erasme, 1070 Bruxelles, Belgium.,Service des Neurosciences, University of Mons, 7000 Mons, Belgium
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Pathogenic Roles of Glutamic Acid Decarboxylase 65 Autoantibodies in Cerebellar Ataxias. J Immunol Res 2017; 2017:2913297. [PMID: 28386570 PMCID: PMC5366212 DOI: 10.1155/2017/2913297] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 12/05/2016] [Accepted: 01/10/2017] [Indexed: 12/12/2022] Open
Abstract
Reports suggesting a pathogenic role of autoantibodies directed against glutamic acid decarboxylase 65 (GAD65Abs) in cerebellar ataxias (CAs) are reviewed, and debatable issues such as internalization of antibodies by neurons and roles of epitopes are discussed. GAD65 is one of two enzymes that catalyze the conversion of glutamate to the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). A pathogenic role of GAD65Ab in CAs is suggested by in vivo and in vitro studies. (1) Intracerebellar administration of cerebrospinal fluid (CSF) immunoglobulins (IgGs) obtained from GAD65Ab-positive CA patients impairs cerebellar modulation of motor control in rats. (2) CSF IgGs act on terminals of GABAergic neurons and decrease the release of GABA in cerebellar slices from rats and mice. (3) Absorption of GAD65Ab by recombinant GAD65 diminishes the above effects, and monoclonal human GAD65Ab (b78) mimic the effects of CSF IgGs in vivo and in vitro. Studies using GAD65-KO mice confirm that the target molecule is GAD65. (4) Notably, the effects of GAD65Ab depend on the epitope specificity of the monoclonal GAD65Ab. Taken together, these results indicate that epitope-specific GAD65Ab-induced impairment of GABA release is involved in the pathogenesis of GAD65Ab-positive CA and support the early detection of GAD65Ab-associated CA to initiate immunotherapy before irreversible neuronal death in the cerebellum.
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Mitoma H, Adhikari K, Aeschlimann D, Chattopadhyay P, Hadjivassiliou M, Hampe CS, Honnorat J, Joubert B, Kakei S, Lee J, Manto M, Matsunaga A, Mizusawa H, Nanri K, Shanmugarajah P, Yoneda M, Yuki N. Consensus Paper: Neuroimmune Mechanisms of Cerebellar Ataxias. CEREBELLUM (LONDON, ENGLAND) 2016; 15:213-32. [PMID: 25823827 PMCID: PMC4591117 DOI: 10.1007/s12311-015-0664-x] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In the last few years, a lot of publications suggested that disabling cerebellar ataxias may develop through immune-mediated mechanisms. In this consensus paper, we discuss the clinical features of the main described immune-mediated cerebellar ataxias and address their presumed pathogenesis. Immune-mediated cerebellar ataxias include cerebellar ataxia associated with anti-GAD antibodies, the cerebellar type of Hashimoto's encephalopathy, primary autoimmune cerebellar ataxia, gluten ataxia, Miller Fisher syndrome, ataxia associated with systemic lupus erythematosus, and paraneoplastic cerebellar degeneration. Humoral mechanisms, cell-mediated immunity, inflammation, and vascular injuries contribute to the cerebellar deficits in immune-mediated cerebellar ataxias.
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Affiliation(s)
- Hiroshi Mitoma
- Department of Medical Education, Tokyo Medical University, Tokyo, Japan.
| | - Keya Adhikari
- Department of Haematology, Nil Ratan Sircar Medical College, 138 A J C Bose Road, Kolkata, 700014, West Bengal, India
| | - Daniel Aeschlimann
- Matrix Biology &Tissue Repair Research Unit, School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Cardiff, Wales, UK
| | - Partha Chattopadhyay
- Department of General Medicine, College of Medicine & Sagore Dutta Hospital, 578 B T Road, Kamarhati-Kolkata, 700056, West Bengal, India
| | | | - Christiane S Hampe
- School of Medicine, University of Washington, 850 Republication, Seattle, WA, 98109, USA
| | - Jérôme Honnorat
- University Lyon 1, University Lyon, Rue Guillaume Paradin, 69372, Lyon Cedex 08, France
- INSERM, UMR-S1028, CNRS, UMR-5292, Neuro-Oncology and Neuro-Inflammation Team, 7, Lyon Neuroscience Research Center, Rue Guillaume Paradin, 69372, Lyon Cedex 08, France
- National Reference Centre for Paraneoplastic Neurological Diseases, Hospices Civils de Lyon, Hôpital Neurologique, 69677, Bron, France
- Hospices Civils de Lyon, Neuro-oncology, Hôpital Neurologique, 69677, Bron, France
| | - Bastien Joubert
- University Lyon 1, University Lyon, Rue Guillaume Paradin, 69372, Lyon Cedex 08, France
- INSERM, UMR-S1028, CNRS, UMR-5292, Neuro-Oncology and Neuro-Inflammation Team, 7, Lyon Neuroscience Research Center, Rue Guillaume Paradin, 69372, Lyon Cedex 08, France
| | - Shinji Kakei
- Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Jongho Lee
- Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Mario Manto
- Unité d'Etude du Mouvement, FNRS, Neurologie ULB-Erasme, 808 Route de Lennik, 1070, Brussels, Belgium
| | - Akiko Matsunaga
- Department of Neurology, University of Fukui Hospital, Fukui, Japan
| | | | - Kazunori Nanri
- Department of Neurology, Tokyo Medical University Hachioji Medical Center, Tokyo, Japan
| | - Priya Shanmugarajah
- Academic Department of Neurosciences, Royal Hallamshire Hospital, Sheffield, UK
| | - Makoto Yoneda
- Faculty of Nursing and Social Welfare Sciences, Fukui Prefectural University, Fukui, Japan
| | - Nobuhiro Yuki
- Departments of Medicine and Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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Stemmler N, Rohleder K, Malter MP, Widman G, Elger CE, Beck H, Surges R. Serum from a Patient with GAD65 Antibody-Associated Limbic Encephalitis Did Not Alter GABAergic Neurotransmission in Cultured Hippocampal Networks. Front Neurol 2015; 6:189. [PMID: 26379623 PMCID: PMC4551833 DOI: 10.3389/fneur.2015.00189] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 08/14/2015] [Indexed: 01/08/2023] Open
Abstract
Background Glutamate decarboxylase is an intracellular enzyme converting glutamate into GABA. Antibodies (abs) to its isoform GAD65 were described in limbic encephalitis and other neurological conditions. The significance of GAD65 abs for epilepsy is unclear, but alterations of inhibitory GABAergic neurotransmission may be involved. Here, we investigated the effects of the serum of a female patient suffering from GAD65 ab-associated LE on GABAA currents in cultured hippocampal networks. Methods Spontaneous or evoked post-synaptic GABAA currents were measured in cultured hippocampal neurons prepared from embryonic mice after 11–21 days in vitro using the patch-clamp technique in the whole-cell mode after incubation with serum of a healthy control or the LE-patient at a final concentration of 1% for 5–8 h. Results Properties of miniature inhibitory post-synaptic currents were not different in cultures treated with control and LE-serum. Likewise, paired-pulse ratio of evoked GABAA currents as a measure of release probability was not different in both conditions. Evoked GABAA currents were significantly depressed during 10 Hz stimulation without significant differences between control and LE-serum treated cultures. Conclusion In our experimental paradigms, serum of a patient with confirmed GAD65 ab-associated LE had no apparent effect on GABAergic neurotransmission in murine-cultured hippocampal networks. These results challenge the view that the presence of GAD65 abs invariably compromise inhibitory network function.
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Affiliation(s)
- Nelly Stemmler
- Department of Epileptology, University Hospital Bonn , Bonn , Germany
| | - Karin Rohleder
- Department of Epileptology, University Hospital Bonn , Bonn , Germany
| | - Michael P Malter
- Department of Epileptology, University Hospital Bonn , Bonn , Germany
| | - Guido Widman
- Department of Epileptology, University Hospital Bonn , Bonn , Germany
| | - Christian E Elger
- Department of Epileptology, University Hospital Bonn , Bonn , Germany
| | - Heinz Beck
- Department of Epileptology, University Hospital Bonn , Bonn , Germany
| | - Rainer Surges
- Department of Epileptology, University Hospital Bonn , Bonn , Germany ; Center for Rare Diseases Bonn (ZSEB), University Hospital Bonn , Bonn , Germany
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Manto M, Honnorat J, Hampe CS, Guerra-Narbona R, López-Ramos JC, Delgado-García JM, Saitow F, Suzuki H, Yanagawa Y, Mizusawa H, Mitoma H. Disease-specific monoclonal antibodies targeting glutamate decarboxylase impair GABAergic neurotransmission and affect motor learning and behavioral functions. Front Behav Neurosci 2015; 9:78. [PMID: 25870548 PMCID: PMC4375997 DOI: 10.3389/fnbeh.2015.00078] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Accepted: 03/12/2015] [Indexed: 12/21/2022] Open
Abstract
Autoantibodies to the smaller isoform of glutamate decarboxylase (GAD) can be found in patients with type 1 diabetes and a number of neurological disorders, including stiff-person syndrome, cerebellar ataxia and limbic encephalitis. The detection of disease-specific autoantibody epitopes led to the hypothesis that distinct GAD autoantibodies may elicit specific neurological phenotypes. We explored the in vitro/in vivo effects of well-characterized monoclonal GAD antibodies. We found that GAD autoantibodies present in patients with stiff person syndrome (n = 7) and cerebellar ataxia (n = 15) recognized an epitope distinct from that recognized by GAD autoantibodies present in patients with type 1 diabetes mellitus (n = 10) or limbic encephalitis (n = 4). We demonstrated that the administration of a monoclonal GAD antibody representing this epitope specificity; (1) disrupted in vitro the association of GAD with γ-Aminobutyric acid containing synaptic vesicles; (2) depressed the inhibitory synaptic transmission in cerebellar slices with a gradual time course and a lasting suppressive effect; (3) significantly decreased conditioned eyelid responses evoked in mice, with no modification of learning curves in the classical eyeblink-conditioning task; (4) markedly impaired the facilitatory effect exerted by the premotor cortex over the motor cortex in a paired-pulse stimulation paradigm; and (5) induced decreased exploratory behavior and impaired locomotor function in rats. These findings support the specific targeting of GAD by its autoantibodies in the pathogenesis of stiff-person syndrome and cerebellar ataxia. Therapies of these disorders based on selective removal of such GAD antibodies could be envisioned.
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Affiliation(s)
- Mario Manto
- Unité d'Etude du Mouvement, FNRS Neurologie, ULB Erasme Brussels, Belgium
| | | | | | | | | | | | - Fumihito Saitow
- Department of Pharmacology, Nippon Medical School Tokyo, Japan
| | - Hidenori Suzuki
- Department of Pharmacology, Nippon Medical School Tokyo, Japan
| | - Yuchio Yanagawa
- Department of Genetic and Behavioral Neuroscience, Gunma University Graduate School of Medicine and JST, CREST, Maebashi City Gunma, Japan
| | | | - Hiroshi Mitoma
- Department of Medical Education, Tokyo Medical University Tokyo, Japan
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Ariño H, Gresa-Arribas N, Blanco Y, Martínez-Hernández E, Sabater L, Petit-Pedrol M, Rouco I, Bataller L, Dalmau JO, Saiz A, Graus F. Cerebellar ataxia and glutamic acid decarboxylase antibodies: immunologic profile and long-term effect of immunotherapy. JAMA Neurol 2014; 71:1009-16. [PMID: 24934144 DOI: 10.1001/jamaneurol.2014.1011] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
IMPORTANCE Current clinical and immunologic knowledge on cerebellar ataxia (CA) with glutamic acid decarboxylase 65 antibodies (GAD65-Abs) is based on case reports and small series with short-term follow-up data. OBJECTIVE To report the symptoms, additional antibodies, prognostic factors, and long-term outcomes in a cohort of patients with CA and GAD65-Abs. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study and laboratory investigations at a center for autoimmune neurologic disorders among 34 patients with CA and GAD65-Abs, including 25 with long-term follow-up data (median, 5.4 years; interquartile range, 3.1-10.3 years). MAIN OUTCOMES AND MEASURES Analysis of clinicoimmunologic features and predictors of response to immunotherapy. Immunochemistry on rat brain, cultured neurons, and human embryonic kidney cells expressing GAD65, GAD67, α1-subunit of the glycine receptor, and a repertoire of known cell surface autoantigens were used to identify additional antibodies. Twenty-eight patients with stiff person syndrome and GAD65-Abs served as controls. RESULTS The median age of patients was 58 years (range, 33-80 years); 28 of 34 patients (82%) were women. Nine patients (26%) reported episodes of brainstem and cerebellar dysfunction or persistent vertigo several months before developing CA. The clinical presentation was subacute during a period of weeks in 13 patients (38%). Nine patients (26%) had coexisting stiff person syndrome symptoms. Systemic organ-specific autoimmunities (type 1 diabetes mellitus and others) were present in 29 patients (85%). Twenty of 25 patients with long-term follow-up data received immunotherapy (intravenous immunoglobulin in 10 and corticosteroids and intravenous immunoglobulin or other immunosuppressors in 10), and 7 of them (35%) improved. Predictors of clinical response included subacute onset of CA (odds ratio [OR], 0.50; 95% CI, 0.25-0.99; P = .047) and prompt immunotherapy (OR, 0.98; 95% CI, 0.96-0.99; P = .01). Similar frequencies of serum GAD67-Abs were found in patients with CA (24 of 34 patients [71%]) and in patients with stiff person syndrome (20 of 28 patients [71%]). However, GAD67-Abs were found in all of the cerebrospinal fluid samples examined (22 samples from patients with CA and 17 samples from patients with stiff person syndrome). Glycine receptor antibodies but not other cell surface antibodies were identified in 4 patients with CA. The presence of glycine receptor antibodies did not correlate with any specific clinical feature. CONCLUSIONS AND RELEVANCE In patients with CA and GAD65-Abs, subacute onset of symptoms and prompt immunotherapy are associated with good outcome. Persistent vertigo or brainstem and cerebellar episodes can herald CA and should lead to GAD65-Ab testing, particularly in patients with systemic organ-specific autoimmunities.
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Affiliation(s)
- Helena Ariño
- Neurology Service, Hospital Clínic, Barcelona, Spain2Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Nuria Gresa-Arribas
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Yolanda Blanco
- Neurology Service, Hospital Clínic, Barcelona, Spain2Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Eugenia Martínez-Hernández
- Neurology Service, Hospital Clínic, Barcelona, Spain2Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Lidia Sabater
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Mar Petit-Pedrol
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Idoia Rouco
- Neurology Service, Department of Neurosciences, Cruces University Hospital, University of the Basque Country, Bizkaia, Spain
| | - Luis Bataller
- Neurology Service, University Hospital Politècnic La Fe, Valencia, Spain
| | - Josep O Dalmau
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain5Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain6Department of Neurology, University of Pennsylvania, Philadelp
| | - Albert Saiz
- Neurology Service, Hospital Clínic, Barcelona, Spain2Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
| | - Francesc Graus
- Neurology Service, Hospital Clínic, Barcelona, Spain2Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona, Barcelona, Spain
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Abstract
Hashimoto's encephalopathy (HE) presents with a variety of neurologic and neuropsychiatric features. Sixteen percentages of HE patients show cerebellar ataxia as a main neurological feature. The clinical features, treatments, laboratory features, brain images, and serum anti-NH(2)-terminal of α-enolase autoantibodies (anti-NAE Abs), which is a useful diagnostic marker of HE, were investigated in 8 patients. They presented with pure cerebellar ataxia and fulfilled the diagnostic criteria for HE based on the presence of anti-thyroid antibodies and responsiveness to immunotherapy, and were compared with clinical features in other autoimmune cerebellar ataxia associated with anti-GAD, anti-gliadin or anti-Yo. All autoimmune cerebellar ataxic patients presented with truncal ataxia, while nystagmus was absent in HE patients. Most of ataxic form of HE patients had insidious onset mimicking spinocerebellar degeneration, but brain magnetic resonance imaging showed no or mild atrophy of the cerebellum in all patients. Ataxic form of HE patients demonstrated an absence of nystagmus and tended to show a better response to immunotherapy. When a pure cerebellar ataxic patient who presents with truncal ataxia without nystagmus and cerebellar atrophy on brain MRI, HE should be considered as a differential diagnosis and anti-NAE Abs should be examined for the screening of this disease.
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Affiliation(s)
- Makoto Yoneda
- Department of Neurology, University of Fukui Hospital
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Abstract
Cancer-associated immune-mediated disorders of the central nervous system are a heterogeneous group. These disorders include the classic paraneoplastic neurologic disorders and the more recently described autoimmune encephalitis associated with antibodies to neuronal cell-surface or synaptic receptors that occur with and without a cancer association. Autoimmune encephalitis is increasingly recognized as the cause of a variety of neuropsychiatric syndromes that can be severe and prolonged. In contrast to the classic paraneoplastic disorders that are poorly responsive to tumor treatment and immunotherapy, autoimmune encephalitis often responds to these treatments, and patients can have full or marked recoveries. As early treatment speeds recovery, reduces disability, and decreases relapses that can occur in about 20% of cases, it is important that the immune pathogenesis of these disorders is recognized.
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Affiliation(s)
- Josep Dalmau
- Institució Catalana de Recerca i Estudis Avançats (ICREA) at Institut d'Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Department of Neurology, Hospital Clínic, University of Barcelona, Barcelona, Spain (J.D.); Hospital Clínic/IDIBAPS, Department of Neurology, Barcelona, Spain (M.R.R.)
| | - Myrna R Rosenfeld
- Institució Catalana de Recerca i Estudis Avançats (ICREA) at Institut d'Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Department of Neurology, Hospital Clínic, University of Barcelona, Barcelona, Spain (J.D.); Hospital Clínic/IDIBAPS, Department of Neurology, Barcelona, Spain (M.R.R.)
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Pagano MB, Murinson BB, Tobian AA, King KE. Efficacy of therapeutic plasma exchange for treatment of stiff-person syndrome. Transfusion 2014; 54:1851-6. [DOI: 10.1111/trf.12573] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 11/07/2013] [Accepted: 11/14/2013] [Indexed: 11/30/2022]
Affiliation(s)
| | - Beth B. Murinson
- Department of Neurology; The Johns Hopkins Medical Institutions; Baltimore Maryland
| | - Aaron A.R. Tobian
- Department of Pathology; Transfusion Medicine Service; The Johns Hopkins Medical Institutions; Baltimore Maryland
| | - Karen E. King
- Department of Pathology; Transfusion Medicine Service; The Johns Hopkins Medical Institutions; Baltimore Maryland
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Hampe CS, Petrosini L, De Bartolo P, Caporali P, Cutuli D, Laricchiuta D, Foti F, Radtke JR, Vidova V, Honnorat J, Manto M. Monoclonal antibodies to 65kDa glutamate decarboxylase induce epitope specific effects on motor and cognitive functions in rats. Orphanet J Rare Dis 2013; 8:82. [PMID: 23738610 PMCID: PMC3680042 DOI: 10.1186/1750-1172-8-82] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 05/29/2013] [Indexed: 01/02/2023] Open
Abstract
Background Stiff Person Syndrome (SPS) is a rare autoimmune movement disorder characterized by the presence of autoantibodies specific to the smaller isoform of glutamate decarboxylase (GAD65). A pathological role of these antibodies has been suggested by their capacity to inhibit GAD65 enzyme activity and by the observation that rats receiving cerebellar injections of GAD65Ab showed cerebellar motor hyperexcitability. To assess the effect of epitope-specific GAD65Ab on cognitive and motor functions, we conducted behavioral experiments in rats that received cerebellar injections with two distinct monoclonal GAD65Ab (b96.11 and b78). Methods Rats received three injections of GAD65Ab b96.11 (5 or 7 μg), GAD65Ab b78 (5 or 7 μg), or saline at the level of three cerebellar nuclei. Animals were submitted to neurological evaluation and Morris Water Maze (MWM) test. Cellular internalization of GAD65Ab was analyzed by Flow Cytometry, Fluorescence and Bright Field microscopy. Results Monoclonal GAD65Ab induced dose-dependent and epitope-specific effects on motor and cognitive functions. Injections of the higher dose altered motor and spatial procedural behaviors, while the lower dose induced only modest cerebellar motor symptoms and did not affect MWM performances. While b96.11 provoked immediate severe effects, which rapidly decreased, b78 induced moderate but prolonged effects. Both GAD65Ab were taken up by live cells in a dose-dependent manner. Conclusions Our findings support the hypothesis that epitope-specific GAD65Ab induce cerebellar dysfunction impairing motor and procedural abilities. This is the first demonstration of a critical role of cerebellar nuclei GAD65 enzyme in procedural spatial functions.
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Affiliation(s)
- Christiane S Hampe
- University of Washington, School of Medicine, SLU S-276, Seattle, WA 98109, USA.
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Abstract
The discovery of disorders that are associated with antibodies to neuronal cell-surface proteins has led to a paradigm shift in our understanding of CNS autoimmunity. These disorders can occur in patients with or without cancer-often children or young adults who develop psychosis, catatonic or autistic features, memory problems, abnormal movements, or seizures that were previously considered idiopathic. The autoantigens in such cases have crucial roles in synaptic transmission, plasticity and peripheral nerve excitability. Patients can be comatose or encephalopathic for months and yet fully recover with supportive care and immunotherapy. By contrast, disorders in which the antibodies target intracellular antigens, and in which T-cell-mediated irreversible neuronal degeneration occurs, show a considerably poorer response to treatment. In this article, we review the various targets of neuronal antibodies, focusing predominantly on autoantigens located on the cell surface or synapses-namely, N-methyl-D-aspartate receptors, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors, γ-aminobutyric acid receptors, leucine-rich glioma-inactivated protein 1, contactin-associated protein-like 2, and metabotropic glutamate receptors. We also provide an algorithm to identify and assess antibodies that bind to cell-surface and synaptic antigens.
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Affiliation(s)
- Eric Lancaster
- Department of Neurology, 3 W Gates, 3400 Spruce Street, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Rout UK, Mungan NK, Dhossche DM. Presence of GAD65 autoantibodies in the serum of children with autism or ADHD. Eur Child Adolesc Psychiatry 2012; 21:141-7. [PMID: 22323074 DOI: 10.1007/s00787-012-0245-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2011] [Accepted: 01/13/2012] [Indexed: 11/30/2022]
Abstract
Antibodies against glutamic acid decarboxylase 65 (GAD65) have been detected in the serum of patients with several neurological disorders. The presence of antibodies against GAD65 has not yet been examined in the serum of patients with neurodevelopmental disorders such as autism or attention-deficit/hyperactivity disorder (ADHD). In this study, GAD65 antibodies and total IgG were assayed in the serum of normal subjects and patients diagnosed with autism or ADHD. GAD65 antibodies were detected in the serum of 15% of children with autism (N = 20), 27% of children with ADHD (N = 15) and of none of the controls (N = 14). The serum of 60% of autistic and 53% of ADHD patients reacted with Purkinje neurons in mouse cerebellum. Serum from 20% of ADHD patients reacted also with the cells in the molecular and granule cell layers and cells in the vicinity of the Purkinje neurons. No association was found between the titer of GAD65 antibodies and total IgG levels, and presence of seizures or mental retardation. None of the ADHD patients were diagnosed with mental retardation. Serum anti-GAD65 antibodies may be a common marker of subgroups of patients with autism and ADHD. Reactions of serum antibodies with the cells in the cerebellum in these patients suggest direct effects on brain function. The subgroup of children with autism and ADHD that tests positive for GAD65 antibodies needs further characterization in a larger study.
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Affiliation(s)
- Ujjwal K Rout
- Department of Surgery, University of Mississippi Medical Center, Clinical Sciences Building, Room L020, Jackson, MS, 39216, USA.
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