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Saiz A, Graus F. Neuronal antibodies in nonparaneoplastic autoimmune cerebellar ataxias. Curr Opin Neurol 2024; 37:322-328. [PMID: 38483149 DOI: 10.1097/wco.0000000000001260] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2024]
Abstract
PURPOSE OF REVIEW To describe relevant advances in nonparaneoplastic autoimmune cerebellar ataxias (ACA) with neuronal antibodies. RECENT FINDINGS Apart from metabotropic glutamate receptor 1(mGluR1) antibodies, in recent years, the number of neuronal antibodies against surface antigens in ACA has increased with the description of glutamate kainate receptor subunit 2 (GluK2) antibodies in young patients with cerebellitis. Around 20% of patients with contactin-associated protein-like 2 (CASPR2) encephalitis also present prominent cerebellar ataxia. However, isolate cerebellar ataxia is unusual (<4%). Outcome in patients with neuronal antibodies against surface antigens remains suboptimal despite the cerebellar ataxia probably is antibody-mediated.Concerning neuronal antibodies against intracellular antigens, up to 25% of patients with glutamic acid decarboxylase (GAD) antibodies present transient episodes of vertigo or diplopia that antedate the development of the ACA. There is in-vitro evidence that septin-5 is partially exposed to the membrane and the antibodies may interfere with septin-5 function. The clinical significance of the remaining antibodies against intracellular antigens remains unclear. SUMMARY The number of antibodies against surface antigens is increasing in ACA, but the response to the immunotherapy remains suboptimal. More studies are needed to clarify the role of most of the antibodies against intracellular antigens described in these patients.
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Affiliation(s)
- Albert Saiz
- Service of Neurology, Hospital Clinic
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Francesc Graus
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
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2
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Segal Y, Zekeridou A. Interest of rare autoantibodies in autoimmune encephalitis and paraneoplastic neurological syndromes: the utility (or futility) of rare antibody discovery. Curr Opin Neurol 2024; 37:295-304. [PMID: 38533672 DOI: 10.1097/wco.0000000000001261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
PURPOSE OF REVIEW The increasing recognition and diagnosis of autoimmune encephalitis (AE) and paraneoplastic neurological syndromes (PNS) is partly due to neural autoantibody testing and discovery. The past two decades witnessed an exponential growth in the number of identified neural antibodies. This review aims to summarize recent rare antibody discoveries in the context of central nervous system (CNS) autoimmunity and evaluate the ongoing debate about their utility. RECENT FINDINGS In the last 5 years alone 15 novel neural autoantibody specificities were identified. These include rare neural antibody biomarkers of autoimmune encephalitis, cerebellar ataxia or other movement disorders, including multifocal presentations. SUMMARY Although the clinical applications of these rare antibody discoveries may be limited by the low number of positive cases, they still provide important diagnostic, prognostic, and therapeutic insights.
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Affiliation(s)
- Yahel Segal
- Department of Laboratory Medicine and Pathology
| | - Anastasia Zekeridou
- Department of Laboratory Medicine and Pathology
- Department of Neurology
- Center for Multiple Sclerosis and Autoimmune Neurology, Mayo Clinic, Rochester, Minnesota, USA
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Papi C, Milano C, Spatola M. Mechanisms of autoimmune encephalitis. Curr Opin Neurol 2024; 37:305-315. [PMID: 38667756 DOI: 10.1097/wco.0000000000001270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2024]
Abstract
PURPOSE OF REVIEW To provide an overview of the pathogenic mechanisms involved in autoimmune encephalitides mediated by antibodies against neuronal surface antigens, with a focus on NMDAR and LGI1 encephalitis. RECENT FINDINGS In antibody-mediated encephalitides, binding of IgG antibodies to neuronal surface antigens results in different pathogenic effects depending on the type of antibody, IgG subclass and epitope specificity. NMDAR IgG1 antibodies cause crosslinking and internalization of the target, synaptic and brain circuitry alterations, as well as alterations of NMDAR expressing oligodendrocytes, suggesting a link with white matter lesions observed in MRI studies. LGI1 IgG4 antibodies, instead, induce neuronal dysfunction by disrupting the interaction with cognate proteins and altering AMPAR-mediated signaling. In-vitro findings have been corroborated by memory and behavioral changes in animal models obtained by passive transfer of patients' antibodies or active immunization. These models have been fundamental to identify targets for innovative therapeutic strategies, aimed at counteracting or preventing antibody effects, such as the use of soluble ephrin-B2, NMDAR modulators (e.g., pregnenolone, SGE-301) or chimeric autoantibody receptor T cells (CAART) in models of NMDAR encephalitis. SUMMARY A deep understanding of the pathogenic mechanisms underlying antibody-mediated encephalitides is crucial for the development of new therapeutic approaches targeting brain autoimmunity.
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Affiliation(s)
- Claudia Papi
- Department of Neuroscience, Catholic University of the Sacred Heart, Rome, Italy
- Fundació Recerca Biomedica Clinic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (FRBC-IDIBAPS), Barcelona, Spain
| | - Chiara Milano
- Fundació Recerca Biomedica Clinic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (FRBC-IDIBAPS), Barcelona, Spain
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Marianna Spatola
- Fundació Recerca Biomedica Clinic - Institut d'Investigacions Biomèdiques August Pi i Sunyer (FRBC-IDIBAPS), Barcelona, Spain
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4
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Sanvito F, Pichiecchio A, Paoletti M, Rebella G, Resaz M, Benedetti L, Massa F, Morbelli S, Caverzasi E, Asteggiano C, Businaro P, Masciocchi S, Castellan L, Franciotta D, Gastaldi M, Roccatagliata L. Autoimmune encephalitis: what the radiologist needs to know. Neuroradiology 2024; 66:653-675. [PMID: 38507081 PMCID: PMC11031487 DOI: 10.1007/s00234-024-03318-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 02/20/2024] [Indexed: 03/22/2024]
Abstract
Autoimmune encephalitis is a relatively novel nosological entity characterized by an immune-mediated damage of the central nervous system. While originally described as a paraneoplastic inflammatory phenomenon affecting limbic structures, numerous instances of non-paraneoplastic pathogenesis, as well as extra-limbic involvement, have been characterized. Given the wide spectrum of insidious clinical presentations ranging from cognitive impairment to psychiatric symptoms or seizures, it is crucial to raise awareness about this disease category. In fact, an early diagnosis can be dramatically beneficial for the prognosis both to achieve an early therapeutic intervention and to detect a potential underlying malignancy. In this scenario, the radiologist can be the first to pose the hypothesis of autoimmune encephalitis and refer the patient to a comprehensive diagnostic work-up - including clinical, serological, and neurophysiological assessments.In this article, we illustrate the main radiological characteristics of autoimmune encephalitis and its subtypes, including the typical limbic presentation, the features of extra-limbic involvement, and also peculiar imaging findings. In addition, we review the most relevant alternative diagnoses that should be considered, ranging from other encephalitides to neoplasms, vascular conditions, and post-seizure alterations. Finally, we discuss the most appropriate imaging diagnostic work-up, also proposing a suggested MRI protocol.
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Affiliation(s)
- Francesco Sanvito
- Unit of Radiology, Department of Clinical, Surgical, Diagnostic, and Paediatric Sciences, University of Pavia, Viale Camillo Golgi, 19, 27100, Pavia, Italy.
- UCLA Brain Tumor Imaging Laboratory (BTIL), Center for Computer Vision and Imaging Biomarkers, University of California Los Angeles, Los Angeles, CA, USA.
- Department of Radiological Sciences, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
| | - Anna Pichiecchio
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- Advanced Imaging and Artificial Intelligence Center, Department of Neuroradiology, IRCCS Mondino Foundation, Via Mondino 2, 27100, Pavia, Italy
| | - Matteo Paoletti
- Advanced Imaging and Artificial Intelligence Center, Department of Neuroradiology, IRCCS Mondino Foundation, Via Mondino 2, 27100, Pavia, Italy
| | - Giacomo Rebella
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genoa, Italy
| | - Martina Resaz
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genoa, Italy
| | - Luana Benedetti
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genoa, Italy
| | - Federico Massa
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genoa, Italy
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Largo Daneo 3, 16132, Genoa, Italy
| | - Silvia Morbelli
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genoa, Italy
- Department of Health Sciences (DISSAL), University of Genoa, Via Antonio Pastore 1, 16132, Genoa, Italy
| | - Eduardo Caverzasi
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- Advanced Imaging and Artificial Intelligence Center, Department of Neuroradiology, IRCCS Mondino Foundation, Via Mondino 2, 27100, Pavia, Italy
| | - Carlo Asteggiano
- Advanced Imaging and Artificial Intelligence Center, Department of Neuroradiology, IRCCS Mondino Foundation, Via Mondino 2, 27100, Pavia, Italy
| | - Pietro Businaro
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- Neuroimmunology Laboratory and Neuroimmunology Research Section, IRCCS Mondino Foundation, Via Mondino 2, 27100, Pavia, Italy
| | - Stefano Masciocchi
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- Neuroimmunology Laboratory and Neuroimmunology Research Section, IRCCS Mondino Foundation, Via Mondino 2, 27100, Pavia, Italy
| | - Lucio Castellan
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genoa, Italy
| | - Diego Franciotta
- Neuroimmunology Laboratory and Neuroimmunology Research Section, IRCCS Mondino Foundation, Via Mondino 2, 27100, Pavia, Italy
| | - Matteo Gastaldi
- Neuroimmunology Laboratory and Neuroimmunology Research Section, IRCCS Mondino Foundation, Via Mondino 2, 27100, Pavia, Italy
| | - Luca Roccatagliata
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132, Genoa, Italy
- Department of Health Sciences (DISSAL), University of Genoa, Via Antonio Pastore 1, 16132, Genoa, Italy
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Iizuka M, Nagata N, Kanazawa N, Iwami T, Nagashima M, Nakamura M, Kaneko J, Kitamura E, Nishiyama K, Mamorita N, Iizuka T. H-intensity scale score to estimate CSF GluN1 antibody titers with one-time immunostaining using a commercial assay. Front Immunol 2024; 15:1350837. [PMID: 38745654 PMCID: PMC11091310 DOI: 10.3389/fimmu.2024.1350837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 03/25/2024] [Indexed: 05/16/2024] Open
Abstract
Introduction Anti-NMDA receptor encephalitis is an autoimmune disorder caused by autoantibodies (abs) against the conformational epitope on GluN1 subunits. GluN1-abs have been determined with cell-based assay (CBA) co-expressing GluN1/GluN2 subunits. However, commercial fixed CBA expressing only GluN1 subunit has increasingly been used in clinical practice. The ab titers can be determined with serial dilutions, but its clinical significance remains unclear. We aimed to develop an H-intensity scale (HIS) score to estimate GluN1-ab titers in cerebrospinal fluid (CSF) with one-time immunostaining using both commercial CBA and immunohistochemistry and report its usefulness. "H" is the initial of a patient with high CSF GluN1-ab titers (1:2,048). Methods We first determined the reliability of CBA in 370 patients with suspected autoimmune encephalitis by comparing the results between commercial CBA and established assay in Dalmau's Lab. Then, we made positive control panels using the patient H's CSF diluted in a fourfold serial dilution method (1:2, 1:8, 1:32, 1:128, 1:512, and 1:2,048). Based on the panels, we scored the intensity of ab reactivity of 79 GluN1-ab-positive patients' CSF (diluted at 1:2) on a scale from 0 to 6 (with ≥1 considered positive). To assess inter-assay reliability, we performed immunostaining twice in 21 patients' CSF. We investigated an association between the score of CSF obtained at diagnosis and the clinical/paraclinical features. Results The sensitivity and specificity of CBA were 93.7% (95% CI: 86.0-97.3) and 98.6% (95% CI: 96.5-99.5), respectively. Linear regression analysis showed a good agreement between the scores of the first and second assays. Patients with a typical spectrum, need for mechanical ventilation support, autonomic symptoms/central hypoventilation, dyskinesias, speech dysfunction, decreased level of consciousness, preceding headache, ovarian teratoma, and CSF leukocyte count >20 cells/µL had a higher median HIS score than those without, but HIS score was not associated with sex, age at onset, or seizure. HIS score at diagnosis had a significant effect on 1-year functional status. Discussion The severity of disease and four of the six core symptoms were associated with higher GluN1-ab titers in CSF at diagnosis, which may play a role in poor 1-year functional status. An incomplete phenotype can be attributed to low CSF GluN1-ab titers.
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Affiliation(s)
- Masaki Iizuka
- Department of Neurology, Kitasato University School of Medicine, Sagamihara, Japan
| | - Naomi Nagata
- Department of Neurology, Kitasato University School of Medicine, Sagamihara, Japan
| | - Naomi Kanazawa
- Department of Neurology, Kitasato University School of Medicine, Sagamihara, Japan
| | - Tomomi Iwami
- Department of Neurology, Kitasato University School of Medicine, Sagamihara, Japan
| | - Makoto Nagashima
- Department of Neurology, Kitasato University School of Medicine, Sagamihara, Japan
| | - Masaaki Nakamura
- Department of Neurology, Kitasato University School of Medicine, Sagamihara, Japan
| | - Juntaro Kaneko
- Department of Neurology, Kitasato University School of Medicine, Sagamihara, Japan
| | - Eiji Kitamura
- Department of Neurology, Kitasato University School of Medicine, Sagamihara, Japan
| | - Kazutoshi Nishiyama
- Department of Neurology, Kitasato University School of Medicine, Sagamihara, Japan
| | - Noritaka Mamorita
- Department of Medical Informatics, Kitasato University School of Allied Health Sciences, Sagamihara, Japan
| | - Takahiro Iizuka
- Department of Neurology, Kitasato University School of Medicine, Sagamihara, Japan
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6
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Hahn C, Budhram A, Alikhani K, AlOhaly N, Beecher G, Blevins G, Brooks J, Carruthers R, Comtois J, Cowan J, de Robles P, Hébert J, Kapadia RK, Lapointe S, Mackie A, Mason W, McLane B, Muccilli A, Poliakov I, Smyth P, Williams KG, Uy C, McCombe JA. Canadian Consensus Guidelines for the Diagnosis and Treatment of Autoimmune Encephalitis in Adults. Can J Neurol Sci 2024:1-21. [PMID: 38312020 DOI: 10.1017/cjn.2024.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2024]
Abstract
Autoimmune encephalitis is increasingly recognized as a neurologic cause of acute mental status changes with similar prevalence to infectious encephalitis. Despite rising awareness, approaches to diagnosis remain inconsistent and evidence for optimal treatment is limited. The following Canadian guidelines represent a consensus and evidence (where available) based approach to both the diagnosis and treatment of adult patients with autoimmune encephalitis. The guidelines were developed using a modified RAND process and included input from specialists in autoimmune neurology, neuropsychiatry and infectious diseases. These guidelines are targeted at front line clinicians and were created to provide a pragmatic and practical approach to managing such patients in the acute setting.
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Affiliation(s)
- Christopher Hahn
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada
| | - Adrian Budhram
- Clinical Neurological Sciences, London Health Sciences Centre, London, ON, Canada
- Department of Pathology and Laboratory Medicine, Western University, London Health Sciences Centre, London, ON, Canada
| | - Katayoun Alikhani
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada
| | - Nasser AlOhaly
- Division of Neurology, University of Toronto, Toronto, ON, Canada
| | - Grayson Beecher
- Division of Neurology, University of Alberta, Edmonton, AB, Canada
| | - Gregg Blevins
- Division of Neurology, University of Alberta, Edmonton, AB, Canada
| | - John Brooks
- Division of Neurology, University of Toronto, Toronto, ON, Canada
| | - Robert Carruthers
- Division of Neurology, University of British Columbia, Vancouver, BC, Canada
| | - Jacynthe Comtois
- Neurosciences, Universite de Montreal Faculte de Medecine, Montreal, QC, Canada
| | - Juthaporn Cowan
- Division of Infectious Diseases, Department of Medicine Ottawa Hospital, Ottawa, ON, Canada
| | - Paula de Robles
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada
- Department of Oncology, University of Calgary, Calgary, AB, Canada
| | - Julien Hébert
- Division of Neurology, University of Toronto, Toronto, ON, Canada
| | - Ronak K Kapadia
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada
| | - Sarah Lapointe
- Neurosciences, Universite de Montreal Faculte de Medecine, Montreal, QC, Canada
| | - Aaron Mackie
- Department of Psychiatry, University of Calgary, Calgary, AB, Canada
| | - Warren Mason
- Division of Neurology, University of Toronto, Toronto, ON, Canada
| | - Brienne McLane
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada
- Department of Psychiatry, University of Calgary, Calgary, AB, Canada
| | | | - Ilia Poliakov
- Division of Neurology, University of Saskatchewan College of Medicine, Saskatoon, SK, Canada
| | - Penelope Smyth
- Division of Neurology, University of Alberta, Edmonton, AB, Canada
| | | | - Christopher Uy
- Division of Neurology, University of British Columbia, Vancouver, BC, Canada
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7
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Budhram A, Flanagan EP. Optimizing the diagnostic performance of neural antibody testing for paraneoplastic and autoimmune encephalitis in clinical practice. HANDBOOK OF CLINICAL NEUROLOGY 2024; 200:365-382. [PMID: 38494290 DOI: 10.1016/b978-0-12-823912-4.00002-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
The detection of neural antibodies in patients with paraneoplastic and autoimmune encephalitis has majorly advanced the diagnosis and management of neural antibody-associated diseases. Although testing for these antibodies has historically been restricted to specialized centers, assay commercialization has made this testing available to clinical chemistry laboratories worldwide. This improved test accessibility has led to reduced turnaround time and expedited diagnosis, which are beneficial to patient care. However, as the utilization of these assays has increased, so too has the need to evaluate how they perform in the clinical setting. In this chapter, we discuss assays for neural antibody detection that are in routine use, draw attention to their limitations and provide strategies to help clinicians and laboratorians overcome them, all with the aim of optimizing neural antibody testing for paraneoplastic and autoimmune encephalitis in clinical practice.
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Affiliation(s)
- Adrian Budhram
- Department of Clinical Neurological Sciences, Western University, London Health Sciences Centre, London, ON, Canada; Department of Pathology and Laboratory Medicine, Western University, London Health Sciences Centre, London, ON, Canada.
| | - Eoin P Flanagan
- Department of Neurology, Mayo Clinic, Rochester, MN, United States; Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States
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8
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Kadish R, Clardy SL. Epidemiology of paraneoplastic neurologic syndromes. HANDBOOK OF CLINICAL NEUROLOGY 2024; 200:57-77. [PMID: 38494297 DOI: 10.1016/b978-0-12-823912-4.00011-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Paraneoplastic neurologic syndromes (PNS), initially depicted as seemingly cryptic remote manifestations of malignancy, were first described clinically in the early 20th century, with pathophysiologic correlates becoming better elucidated in the latter half of the century. There remain many questions not only about the pathophysiology but also regarding the epidemiology of these conditions. The continuous discovery of novel autoantigens and related neurologic disease has broadened the association in classical PNS to include conditions such as paraneoplastic cerebellar degeneration. It has also brought into focus several other neurologic syndromes with a putative neoplastic association. These conditions are overall rare, making it difficult to capture large numbers of patients to study, and raising the question of whether incidence is increasing over time or improved identification is driving the increased numbers of cases. With the rise and increasing use of immunotherapy for cancer treatment, the incidence of these conditions is additionally expected to rise and may present with various clinical symptoms. As we enter an era of clinical trial intervention in these conditions, much work is needed to capture more granular data on population groups defined by socioeconomic characteristics such as age, ethnicity, economic resources, and gender to optimize care and clinical trial planning.
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Affiliation(s)
- Robert Kadish
- Department of Neurology, University of Utah, Salt Lake City, UT, United States
| | - Stacey L Clardy
- Department of Neurology, University of Utah, Salt Lake City, UT, United States; George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, UT, United States.
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9
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Dalmau J. Changing landscape in the field of paraneoplastic neurology: Personal perspectives over a 35-year career. HANDBOOK OF CLINICAL NEUROLOGY 2024; 200:11-32. [PMID: 38494272 DOI: 10.1016/b978-0-12-823912-4.00013-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Paraneoplastic neurologic syndromes are a group of rare disorders that have fascinated neurologists for more than a century. The discovery in the 1980s that many of these disorders occurred in association with antibodies against neuronal proteins revived the interest for these diseases. This chapter first traces the history of the paraneoplastic neurologic syndromes during the era that preceded the discovery of immune mechanisms and then reviews the immunologic period during which many of these syndromes were found to be associated with antibodies against intracellular onconeuronal proteins and pathogenic cytotoxic T-cell mechanisms. Alongside these developments, investigations on the antibody-mediated disorders of the peripheral nervous system, such as the myasthenic syndromes or neuromyotonia, provided suggestions for the study of the central nervous system (CNS) syndromes. These converging areas of research culminated with the groundbreaking discovery of a new category of CNS disorders mediated by antibodies against neuronal surface proteins or receptors. These disorders are not always paraneoplastic, and the understanding of these syndromes and mechanisms has changed the landscape of neurology and neurosciences.
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Affiliation(s)
- Josep Dalmau
- IDIBAPS-Hospital Clinic, University of Barcelona, Barcelona, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain.
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10
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Kudo A, Yaguchi H, Tanaka K, Kimura A, Yabe I. A retrospective study of autoimmune cerebellar ataxia over a 20-year period in a single institution. J Neurol 2024; 271:553-563. [PMID: 37610447 DOI: 10.1007/s00415-023-11946-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 07/08/2023] [Accepted: 08/14/2023] [Indexed: 08/24/2023]
Abstract
BACKGROUND It is important to differentiate autoimmune cerebellar ataxia (ACA) from neurodegenerative CA, but this is sometimes difficult. We performed a retrospective study in a single institution in Japan over a 20-year period to reveal the clinical features of ACA. METHODS Patients with CA as the primary neurological symptom were enrolled from those admitted to the Department of Neurology, Hokkaido University Hospital between April 2002 and March 2022. ACA was diagnosed retrospectively according to the following criteria: (1) CA being the predominant symptom; (2) identification of cancer within 2 years of onset; (3) improvement in cerebellar symptoms following immunotherapy; and (4) ruling out alternative causes of CA. Patients fulfilling criteria (1), (2), and (4) were classified as paraneoplastic cerebellar degeneration (PCD), while those fulfilling (1), (3), and (4) were classified as non-PCD and enrolled as patients with ACA. Neurodegenerative diseases, e.g., multiple system atrophy (MSA), were confirmed retrospectively based on generally used diagnostic criteria and enrolled. Furthermore, the ACA diagnostic criteria proposed by Dalmau and Graus were applied retrospectively to the ACA patients to examine the validity of the diagnoses. RESULTS Among the 243 patients with CA, 13 were enrolled as ACA; five were PCD and eight were non-PCD. Eight of these cases met the proposed diagnostic criteria by Dalmau and Graus. MSA was the most prevalent disease among CA patients, with 93 cases. The incidence of cerebellar atrophy was significantly lower in ACA (3/13) than in MSA (92/92). Cerebrospinal fluid (CSF) pleocytosis was significantly more frequent in ACA than in MSA (4/13 vs. 2/55, respectively). However, there was no significant difference in the presence of oligoclonal bands, increased protein in CSF, and laterality differences in ataxia. CONCLUSION ACA was present in ~ 5% of Japanese CA patients. The absence of cerebellar atrophy, despite the presence of CA, strongly supports ACA over MSA. While CSF pleocytosis was observed more often in ACA, the positivity rate was only ~ 30%. Since ACA is treatable, further studies are needed to identify additional clinical features and accurate diagnostic biomarkers.
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Affiliation(s)
- Akihiko Kudo
- Department of Neurology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N-15 W-7, Kita-Ku, Sapporo, Japan
| | - Hiroaki Yaguchi
- Department of Neurology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N-15 W-7, Kita-Ku, Sapporo, Japan.
| | - Keiko Tanaka
- Department of Animal Model Development, Brain Research Institute, Niigata University, Niigata, Japan
| | - Akio Kimura
- Department of Neurology, Gifu University Graduate School of Medicine, Gifu, Japan
| | - Ichiro Yabe
- Department of Neurology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, N-15 W-7, Kita-Ku, Sapporo, Japan.
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11
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Masciocchi S, Businaro P, Scaranzin S, Morandi C, Franciotta D, Gastaldi M. General features, pathogenesis, and laboratory diagnostics of autoimmune encephalitis. Crit Rev Clin Lab Sci 2024; 61:45-69. [PMID: 37777038 DOI: 10.1080/10408363.2023.2247482] [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: 03/23/2023] [Accepted: 08/09/2023] [Indexed: 10/02/2023]
Abstract
Autoimmune encephalitis (AE) is a group of inflammatory conditions that can associate with the presence of antibodies directed to neuronal intracellular, or cell surface antigens. These disorders are increasingly recognized as an important differential diagnosis of infectious encephalitis and of other common neuropsychiatric conditions. Autoantibody diagnostics plays a pivotal role for accurate diagnosis of AE, which is of utmost importance for the prompt recognition and early treatment. Several AE subgroups can be identified, either according to the prominent clinical phenotype, presence of a concomitant tumor, or type of neuronal autoantibody, and recent diagnostic criteria have provided important insights into AE classification. Antibodies to neuronal intracellular antigens typically associate with paraneoplastic neurological syndromes and poor prognosis, whereas antibodies to synaptic/neuronal cell surface antigens characterize many AE subtypes that associate with tumors less frequently, and that are often immunotherapy-responsive. In addition to the general features of AE, we review current knowledge on the pathogenic mechanisms underlying these disorders, focusing mainly on the potential role of neuronal antibodies in the most frequent conditions, and highlight current theories and controversies. Then, we dissect the crucial aspects of the laboratory diagnostics of neuronal antibodies, which represents an actual challenge for both pathologists and neurologists. Indeed, this diagnostics entails technical difficulties, along with particularly interesting novel features and pitfalls. The novelties especially apply to the wide range of assays used, including specific tissue-based and cell-based assays. These assays can be developed in-house, usually in specialized laboratories, or are commercially available. They are widely used in clinical immunology and in clinical chemistry laboratories, with relevant differences in analytic performance. Indeed, several data indicate that in-house assays could perform better than commercial kits, notwithstanding that the former are based on non-standardized protocols. Moreover, they need expertise and laboratory facilities usually unavailable in clinical chemistry laboratories. Together with the data of the literature, we critically evaluate the analytical performance of the in-house vs commercial kit-based approach. Finally, we propose an algorithm aimed at integrating the present strategies of the laboratory diagnostics in AE for the best clinical management of patients with these disorders.
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Affiliation(s)
- Stefano Masciocchi
- Neuroimmunology Research Section, IRCCS Mondino Foundation, Pavia, Italy
- Department of Brain and Behavioral Sciences, Università degli Studi di Pavia, Pavia, Italy
| | - Pietro Businaro
- Neuroimmunology Research Section, IRCCS Mondino Foundation, Pavia, Italy
- Department of Brain and Behavioral Sciences, Università degli Studi di Pavia, Pavia, Italy
| | - Silvia Scaranzin
- Neuroimmunology Research Section, IRCCS Mondino Foundation, Pavia, Italy
| | - Chiara Morandi
- Neuroimmunology Research Section, IRCCS Mondino Foundation, Pavia, Italy
| | - Diego Franciotta
- Neuroimmunology Research Section, IRCCS Mondino Foundation, Pavia, Italy
| | - Matteo Gastaldi
- Neuroimmunology Research Section, IRCCS Mondino Foundation, Pavia, Italy
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12
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Ryding M, Mikkelsen AW, Nissen MS, Nilsson AC, Blaabjerg M. Pathophysiological Effects of Autoantibodies in Autoimmune Encephalitides. Cells 2023; 13:15. [PMID: 38201219 PMCID: PMC10778077 DOI: 10.3390/cells13010015] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/15/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
The heterogeneity of autoantibody targets in autoimmune encephalitides presents a challenge for understanding cellular and humoral pathophysiology, and the development of new treatment strategies. Thus, current treatment aims at autoantibody removal and immunosuppression, and is primarily based on data generated from other autoimmune neurological diseases and expert consensus. There are many subtypes of autoimmune encephalitides, which now entails both diseases with autoantibodies targeting extracellular antigens and classical paraneoplastic syndromes with autoantibodies targeting intracellular antigens. Here, we review the current knowledge of molecular and cellular effects of autoantibodies associated with autoimmune encephalitis, and evaluate the evidence behind the proposed pathophysiological mechanisms of autoantibodies in autoimmune encephalitis.
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Affiliation(s)
- Matias Ryding
- Department of Clinical Research, University of Southern Denmark, 5000 Odense, Denmark;
- Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5000 Odense, Denmark
| | - Anne With Mikkelsen
- Department of Clinical Immunology, Odense University Hospital, 5000 Odense, Denmark;
| | | | - Anna Christine Nilsson
- Department of Clinical Research, University of Southern Denmark, 5000 Odense, Denmark;
- Department of Clinical Immunology, Odense University Hospital, 5000 Odense, Denmark;
| | - Morten Blaabjerg
- Department of Clinical Research, University of Southern Denmark, 5000 Odense, Denmark;
- Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, 5000 Odense, Denmark
- Department of Neurology, Odense University Hospital, 5000 Odense, Denmark;
- Brain Research—Inter Disciplinary Guided Excellence (BRIDGE), 5000 Odense, Denmark
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13
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Landa J, Serafim AB, Gaig C, Saiz A, Koneczny I, Hoftberger R, Santamaria J, Dalmau J, Graus F, Sabater L. Patients' IgLON5 autoantibodies interfere with IgLON5-protein interactions. Front Immunol 2023; 14:1151574. [PMID: 37033996 PMCID: PMC10073962 DOI: 10.3389/fimmu.2023.1151574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 02/28/2023] [Indexed: 04/11/2023] Open
Abstract
Background Anti-IgLON5 disease is a rare neurological disorder characterized by autoantibodies against IgLON5, and pathological evidence of neurodegeneration. IgLON5 is a cell adhesion molecule but its physiological function is unknown. Our aim was to investigate the IgLON5 interactome and to determine if IgLON5 antibodies (IgLON5-abs) affect these protein interactions. Methods IgLON5 interactome was investigated by mass spectrometry sequencing of proteins immunoprecipitated by IgLON5 autoantibodies using cultures of rat cerebellar granular neurons (CGNs). Shedding of IgLON5 was explored using HEK cells transfected with human IgLON5 plasmid and in CGNs. Interactions of IgLON5 with identified binding partners and IgLON5-abs effects were confirmed by immunofluorescence in transfected HEK cells and rat hippocampal neurons. Results Patients' IgLON5 antibodies co-precipitated all members of the IgLON family and three 3 additional surface proteins. IgLON5 predominantly establishes homomeric and heteromeric cis (within the cell) and trans (between cells)-interactions with other IgLON family members and undergoes spontaneous ectodomain shedding. Antibodies from patients with anti-IgLON5 disease prevent trans-interactions in hippocampal neurons independently of the IgLON5 IgG subclass distribution. Conclusions We show a potentially novel pathogenic mechanism of IgLON5-abs that consists in blocking IgLON5 interactions with its binding partners. These findings extend our knowledge about the physiological role of IgLON5 and pave the way to future understanding of the pathological mechanisms of anti-IgLON5 disease.
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Affiliation(s)
- Jon Landa
- Neuroimmunology Program, Fundació de Recerca Clínic Barcelona-Institut d’Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, Barcelona, Spain
| | - Ana Beatriz Serafim
- Neuroimmunology Program, Fundació de Recerca Clínic Barcelona-Institut d’Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, Barcelona, Spain
| | - Carles Gaig
- Service of Neurology, Hospital Clinic de Barcelona, Barcelona, Spain
| | - Albert Saiz
- Service of Neurology, Hospital Clinic de Barcelona, Barcelona, Spain
| | - Inga Koneczny
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Romana Hoftberger
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
- Comprehensive Center for Clinical Neurosciences and Mental Health, Medical University of Vienna, Vienna, Austria
| | - Joan Santamaria
- Service of Neurology, Hospital Clinic de Barcelona, Barcelona, Spain
| | - Josep Dalmau
- Neuroimmunology Program, Fundació de Recerca Clínic Barcelona-Institut d’Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, Barcelona, Spain
- Service of Neurology, Hospital Clinic de Barcelona, Barcelona, Spain
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Francesc Graus
- Neuroimmunology Program, Fundació de Recerca Clínic Barcelona-Institut d’Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, Barcelona, Spain
| | - Lidia Sabater
- Neuroimmunology Program, Fundació de Recerca Clínic Barcelona-Institut d’Investigacions Biomèdiques August Pi i Sunyer, Universitat de Barcelona, Barcelona, Spain
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14
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Zhang Y, Zhou Q, Peng L, Chen S. Increased Cerebellum 18 F-DPA-714 Uptake in Anti-Glutamate Kainate Receptor Subunit 2 Autoimmune Encephalitis. Ann Neurol 2023; 93:635-636. [PMID: 36480148 DOI: 10.1002/ana.26563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 11/23/2022] [Accepted: 11/25/2022] [Indexed: 12/13/2022]
Affiliation(s)
- Yizongheng Zhang
- Department of Neurology and Institute of Neurology, Ruijin Hospital, affiliated with Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Qinming Zhou
- Department of Neurology and Institute of Neurology, Ruijin Hospital, affiliated with Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lisheng Peng
- Department of Neurology, Third Affiliated Hospital of Sun Yet-Sen University, Guangzhou, China
| | - Sheng Chen
- Department of Neurology and Institute of Neurology, Ruijin Hospital, affiliated with Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
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15
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Nagata N, Kanazawa N, Mitsuhata T, Iizuka M, Nagashima M, Nakamura M, Kaneko J, Kitamura E, Nishiyama K, Iizuka T. Neuronal surface antigen-specific immunostaining pattern on a rat brain immunohistochemistry in autoimmune encephalitis. Front Immunol 2023; 13:1066830. [PMID: 36726989 PMCID: PMC9885155 DOI: 10.3389/fimmu.2022.1066830] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 12/08/2022] [Indexed: 01/18/2023] Open
Abstract
A variety of neuronal surface (NS) antibodies (NS-Ab) have been identified in autoimmune encephalitis (AE). Tissue-based assay (TBA) using a rodent brain immunohistochemistry (IHC) is used to screen NS-Ab, while cell-based assay (CBA) to determine NS antigens. Commercial rat brain IHC is currently available but its clinical relevance remains unclear. Immunostaining patterns of NS antigens have not been extensively studied yet. To address these issues, we assessed a predictive value of "neuropil pattern" and "GFAP pattern" on commercial IHC in 261 patients, and characterized an immunostaining pattern of 7 NS antigens (NMDAR, LGI1, GABAaR, GABAbR, AMPAR, Caspr2, GluK2). Sensitivity and specificity of "neuropil pattern" for predicting NS-Ab were 66.0% (95% CI 55.7-75.3), and 98.2% (95% CI 94.8-99.6), respectively. False-positive rate was 1.8% (3/164) while false-negative rate was 34.0% (33/97). In all 3 false-positive patients, neuropil-like staining was attributed to high titers of GAD65-Ab. In 33 false-negative patients, NMDAR was most frequently identified (n=18 [54.5%], 16/18 [88.9%] had low titers [< 1:32]), followed by GABAaR (n=5). Of 261 patients, 25 (9.6%) had either GFAP (n=21) or GFAP-mimicking pattern (n=4). GFAP-Ab were identified in 21 of 31 patients examined with CBA (20 with GFAP pattern, 1 with GFAP-mimicking pattern). Immunostaining pattern of each NS antigen was as follows: 1) NMDAR revealed homogenous reactivity in the dentate gyrus molecular layer (DG-ML) with less intense dot-like reactivity in the cerebellar granular layer (CB-GL); 2) both GABAaR and GluK2 revealed intense dot-like reactivity in the CB-GL, but GABAaR revealed homogenous reactivity in the DG-ML while GluK2 revealed intense reactivity along the inner layer of the DG-ML; and 3) LGI1, Caspr2, GABAbR, and AMPAR revealed intense reactivity in the cerebellar ML (CB-ML) but LGI1 revealed intense reactivity along the middle layer of the DG-ML. Whereas, Caspr2, GABAbR, and AMPAR revealed similar reactivity in the DG-ML but some difference in other regions. TBA is useful not only for screening NS- or GFAP-Ab but also for estimating NS antigens; however, negative results should be interpreted cautiously because "neuropil pattern" may be missed on commercial IHC when antibody titers are low. Antigen-specific immunoreactivity is a useful biomarker of AE.
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16
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Gaig C, Graus F. Motor symptoms in nonparaneoplastic CNS disorders associated with neural antibodies. HANDBOOK OF CLINICAL NEUROLOGY 2023; 196:277-294. [PMID: 37620074 DOI: 10.1016/b978-0-323-98817-9.00004-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Motor symptoms are common, and sometimes predominant, in almost all nonparaneoplastic CNS disorders associated with neural antibodies. These CNS disorders can be classified into five groups: (1) Autoimmune encephalitis with antibodies against synaptic receptors, (2) cerebellar ataxias associated with neuronal antibodies that mostly target intracellular antigens. (3) Stiff-person syndrome and progressive encephalomyelitis with rigidity and myoclonus which have antibodies against glutamic acid decarboxylase and glycine receptor, respectively. Both diseases have in common the presence of predominant muscle stiffness and rigidity. (4) Three diseases associated with glial antibodies. Two present motor symptoms mainly due to the involvement of the spinal cord: neuromyelitis optica spectrum disorders with aquaporin-4 antibodies and myelin oligodendrocyte glycoprotein antibody-associated disease. The third disorder is the meningoencephalitis associated with glial fibrillar acidic protein antibodies which frequently also presents a myelopathy. (5) Two antibody-related diseases which are characterized by prominent sleep dysfunction: anti-IgLON5 disease, a disorder that frequently presents a variety of movement disorders, and Morvan syndrome associated with contactin-associated protein-like 2 antibodies and clinical manifestations of peripheral nerve hyperexcitability. In this chapter, we describe the main clinical features of these five groups with particular emphasis on the presence, frequency, and types of motor symptoms.
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Affiliation(s)
- Carles Gaig
- Neurology Service, Hospital Clínic of Barcelona, Barcelona, Spain
| | - Francesc Graus
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.
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17
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Muñiz-Castrillo S, Vogrig A, Ciano-Petersen NL, Villagrán-García M, Joubert B, Honnorat J. Novelties in Autoimmune and Paraneoplastic Cerebellar Ataxias: Twenty Years of Progresses. CEREBELLUM (LONDON, ENGLAND) 2022; 21:573-591. [PMID: 35020135 DOI: 10.1007/s12311-021-01363-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
Major advances in our knowledge concerning autoimmune and paraneoplastic cerebellar ataxias have occurred in the last 20 years. The discovery of several neural antibodies represents an undeniable contribution to this field, especially those serving as good biomarkers of paraneoplastic neurological syndromes and those showing direct pathogenic effects. Yet, many patients still lack detectable or known antibodies, and also many antibodies have only been reported in few patients, which makes it difficult to define in detail their clinical value. Nevertheless, a notable progress has additionally been made in the clinical characterization of patients with the main neural antibodies, which, although typically present with a subacute pancerebellar syndrome, may also show either hyperacute or chronic onsets that complicate the differential diagnoses. However, prodromal and transient features could be useful clues for an early recognition, and extracerebellar involvement may also be highly indicative of the associated antibody. Moreover, important advances in our understanding of the pathogenesis of cerebellar ataxias include the description of antibody effects, especially those targeting cell-surface antigens, and first attempts to isolate antigen-specific T-cells. Furthermore, genetic predisposition seems relevant, although differently involved according to cancer association, with particular HLA observed in non-paraneoplastic cases and genetic abnormalities in the tumor cells in paraneoplastic ones. Finally, immune checkpoint inhibitors used as cancer immunotherapy may rarely induce cerebellar ataxias, but even this undesirable effect may in turn serve to shed some light on their physiopathology. Herein, we review the principal novelties of the last 20 years regarding autoimmune and paraneoplastic cerebellar ataxias.
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Affiliation(s)
- Sergio Muñiz-Castrillo
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677, Bron Cedex, France
- SynatAc Team, Institut NeuroMyoGène, INSERM U1217, CNRS, UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Alberto Vogrig
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677, Bron Cedex, France
- SynatAc Team, Institut NeuroMyoGène, INSERM U1217, CNRS, UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Nicolás Lundahl Ciano-Petersen
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677, Bron Cedex, France
- SynatAc Team, Institut NeuroMyoGène, INSERM U1217, CNRS, UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Macarena Villagrán-García
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677, Bron Cedex, France
- SynatAc Team, Institut NeuroMyoGène, INSERM U1217, CNRS, UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Bastien Joubert
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677, Bron Cedex, France
- SynatAc Team, Institut NeuroMyoGène, INSERM U1217, CNRS, UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France
| | - Jérôme Honnorat
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon, Hôpital Neurologique, 59 Boulevard Pinel, 69677, Bron Cedex, France.
- SynatAc Team, Institut NeuroMyoGène, INSERM U1217, CNRS, UMR 5310, Université de Lyon, Université Claude Bernard Lyon 1, Lyon, France.
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18
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Lancaster E. Autoantibody Encephalitis: Presentation, Diagnosis, and Management. J Clin Neurol 2022; 18:373-390. [PMID: 35796263 PMCID: PMC9262450 DOI: 10.3988/jcn.2022.18.4.373] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/22/2022] [Accepted: 04/22/2022] [Indexed: 02/07/2023] Open
Abstract
Autoantibody encephalitis causes distinct clinical syndromes involving alterations in mentation, abnormal movements, seizures, psychiatric symptoms, sleep disruption, spasms, and neuromyotonia. The diagnoses can be confirmed by specific antibody tests, although some antibodies may be better detected in spinal fluid and others in serum. Each disorder conveys a risk of certain tumors which may inform diagnosis and be important for treatment. Autoantibodies to receptors and other neuronal membrane proteins are generally thought to be pathogenic and result in loss of function of the targets, so understanding the pharmacology of the receptors may inform our understanding of the syndromes. Patients may be profoundly ill but the syndromes usually respond to immune therapy, although there are differences in the types of immune therapy that are thought to be most effective for the various disorders.
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Affiliation(s)
- Eric Lancaster
- Department of Neurology, The University of Pennsylvania, Philadelphia, PA, USA.
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19
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Abstract
PURPOSE OF REVIEW Autoimmune encephalitis (AE) refers to immune-mediated neurological syndromes often characterised by the detection of pathogenic autoantibodies in serum and/or cerebrospinal fluid which target extracellular epitopes of neuroglial antigens. There is increasing evidence these autoantibodies directly modulate function of their antigens in vivo. Early treatment with immunotherapy improves outcomes. Yet, these patients commonly exhibit chronic disability. Importantly, optimal therapeutic strategies at onset and during escalation remain poorly understood. In this review of a rapidly emerging field, we evaluate recent studies on larger cohorts, registries, and meta-analyses to highlight existing evidence for contemporary therapeutic approaches in AE. RECENT FINDINGS We highlight acute and long-term treatments used in specific AE syndromes, exemplify how understanding disease pathogenesis can inform precision therapy and outline challenges of defining disability outcomes in AE. SUMMARY Early first-line immunotherapies, including corticosteroids and plasma exchange, improve outcomes, with emerging evidence showing second-line immunotherapies (especially rituximab) reduce relapse rates. Optimal timing of immunotherapy escalation remains unclear. Routine reporting of outcome measures which incorporate cognitive impairment, fatigue, pain, and mental health will permit more accurate quantification of residual disability and comprehensive comparisons between international multicentre cohorts, and enable future meta-analyses with the aim of developing evidence-based therapeutic guidelines.
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Affiliation(s)
- Benjamin P Trewin
- Translational Neuroimmunology Group, Kids Neuroscience Centre, Children's Hospital at Westmead; Sydney Medical School and Brain and Mind Centre, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Isaak Freeman
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Sudarshini Ramanathan
- Translational Neuroimmunology Group, Kids Neuroscience Centre, Children's Hospital at Westmead; Sydney Medical School and Brain and Mind Centre, Faculty of Medicine and Health, University of Sydney, Sydney, Australia
- Department of Neurology, Concord Hospital, Sydney, Australia
| | - Sarosh R Irani
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
- Department of Neurology, John Radcliffe Hospital, Oxford University Hospitals, Oxford, UK
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20
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Rare antibody-mediated and seronegative autoimmune encephalitis: An update. Autoimmun Rev 2022; 21:103118. [PMID: 35595048 DOI: 10.1016/j.autrev.2022.103118] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 05/15/2022] [Indexed: 01/14/2023]
Abstract
Paralleling advances with respect to more common antibody-mediated encephalitides, such as anti-N-methyl-D-aspartate receptor (NMDAR) and anti-leucine-rich glioma-inactivated 1 (LGI1) Ab-mediated encephalitis, the discovery and characterisation of novel antibody-mediated encephalitides accelerated over the past decade, adding further depth etiologically to the spectrum of antibody-mediated encephalitis. Herein, we review the major mechanistic, clinical features and management considerations with respect to anti-γ-aminobutyric acid B (GABAB)-, anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropinoic receptor- (AMPAR), anti-GABAA-, anti-dipeptidyl-peptidase-like protein-6 (DPPX) Ab-mediated encephalitides, delineate rarer subtypes and summarise findings to date regarding seronegative autoimmune encephalitis.
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21
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Gastaldi M, Scaranzin S, Pietro B, Lechiara A, Pesce G, Franciotta D, Lorusso L. Paraneoplastic Neurological Syndromes: Transitioning Between the Old and the New. Curr Oncol Rep 2022; 24:1237-1249. [PMID: 35476177 DOI: 10.1007/s11912-022-01279-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/22/2022] [Indexed: 11/29/2022]
Abstract
PURPOSE OF REVIEW Paraneoplastic neurological syndromes (PNS) are caused by nervous system-targeting aberrant anti-tumoral immune responses. We review the updated criteria for PNS diagnosis, incorporating novel information on clinical phenotypes, neuronal autoantibodies (Nabs), and tumors. The impact of the oncologic use of immune checkpoint inhibitors (ICI) on PNS occurrence is also addressed. RECENT FINDINGS Clinical phenotypes and Nabs are redefined as "high/intermediate/low" risk, following the frequency of cancer association. Nabs, the diagnostic hallmark of PNS, can target intracellular or surface neuronal proteins, with important prognostic and pathogenic implications. Many novel assays have been incorporated into laboratory diagnostics, that is becoming increasingly complex. ICI fight tumors, but favor autoimmunity, thus increasing the incidence of PNS-like disorders. Overcoming the old PNS criteria, the new ones are centered around the presence of tumor. Clinical presentation, Nabs, and tumor findings are translated in diagnostic scores, providing a useful tool for PNS diagnosis and management.
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Affiliation(s)
- Matteo Gastaldi
- Neuroimmunology Laboratory, IRCCS Mondino Foundation, Via Mondino 2, 27100, Pavia, Italy.
| | - Silvia Scaranzin
- Neuroimmunology Laboratory, IRCCS Mondino Foundation, Via Mondino 2, 27100, Pavia, Italy
| | | | - Anastasia Lechiara
- Autoimmunology Laboratory, IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - Giampaola Pesce
- Autoimmunology Laboratory, IRCCS Ospedale Policlinico San Martino, Genova, Italy.,Department of Internal Medicine (Dimi), University of Genova, Genova, Italy
| | - Diego Franciotta
- Autoimmunology Laboratory, IRCCS Ospedale Policlinico San Martino, Genova, Italy
| | - Lorenzo Lorusso
- Neurology and Stroke Unit, Neuroscience Department, A.S.S.T.-Lecco, Merate (LC), Italy
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22
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Xu K, Wang D, He Y, Wang S, Liu G, Pan Y, Jiang H, Peng Y, Xiao F, Huang Y, Wang Q, Wu Y, Pan S, Hu Y. Identification of Anti-Collapsin Response Mediator Protein 2 Antibodies in Patients With Encephalitis or Encephalomyelitis. Front Immunol 2022; 13:854445. [PMID: 35479088 PMCID: PMC9036435 DOI: 10.3389/fimmu.2022.854445] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/14/2022] [Indexed: 12/03/2022] Open
Abstract
Background and Purpose An increasing number of autoimmune encephalitis (AE)-associated autoantibodies have been successfully characterized. However, many cases of AE remain unexplained on account of unknown antibodies. The aim of the present study was to identify a novel antibody against collapsin response mediator protein 2 (CRMP2) in suspected AE patients. Methods A patient’s serum and cerebrospinal fluid samples tested negative for known AE antibodies; however, strong immunolabel signals were observed in the neuronal cytoplasm of the cortex, hippocampus, and Purkinje cells on rat brain sections. Immunoprecipitation from the rat brain protein lysate, followed by mass spectrometry analysis, was used to identify the targeting antigen. Western blotting and cell-based assay with antigen-overexpressing HEK293T cells were used for antibody specificity, epitope, IgG subtype determination, and retrospective study. Results An antibody against CRMP2, a synaptic protein involved in axon guidance, was identified. The immunostains of the patient’s samples on rat brain sections were eliminated by pre-absorption with HEK293T cells overexpressing CRMP2. The samples specifically immunoreacted with CRMP2, but not with CRMP1, CRMP3, CRMP4, and CRMP5. The C-terminus of CRMP2 with 536 amino acids contained the epitope for antibody binding. The subtype analysis showed that the anti-CRMP2 antibody was IgG4. Furthermore, a screening of 46 patients with neurological disoders and neuro-cytoplasm immunostainings on rat brain sections resulted in the identification of anti-CRMP2 antibodies in a case of encephalomyelitis. The two patients responded well to immunotherapies. Conclusions This study discovered that a novel anti-CRMP2 antibody was associated with suspected AE and thus should be included in the testing list for AE.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Yongming Wu
- *Correspondence: Yafang Hu, ; Suyue Pan, ; Yongming Wu,
| | - Suyue Pan
- *Correspondence: Yafang Hu, ; Suyue Pan, ; Yongming Wu,
| | - Yafang Hu
- *Correspondence: Yafang Hu, ; Suyue Pan, ; Yongming Wu,
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