1
|
Morelli L, Serra L, Ricciardiello F, Gligora I, Donadio V, Caprini M, Liguori R, Giannoccaro MP. The role of antibodies in small fiber neuropathy: a review of currently available evidence. Rev Neurosci 2024; 0:revneuro-2024-0027. [PMID: 38865989 DOI: 10.1515/revneuro-2024-0027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Accepted: 05/26/2024] [Indexed: 06/14/2024]
Abstract
Small fiber neuropathy (SFN) is a peripheral nerve condition affecting thin myelinated Aδ and unmyelinated C-fibers, characterized by severe neuropathic pain and other sensory and autonomic symptoms. A variety of medical disorders can cause SFN; however, more than 50% of cases are idiopathic (iSFN). Some investigations suggest an autoimmune etiology, backed by evidence of the efficacy of IVIG and plasma exchange. Several studies suggest that autoantibodies directed against nervous system antigens may play a role in the development of neuropathic pain. For instance, patients with CASPR2 and LGI1 antibodies often complain of pain, and in vitro and in vivo studies support their pathogenicity. Other antibodies have been associated with SFN, including those against TS-HDS, FGFR3, and Plexin-D1, and new potential targets have been proposed. Finally, a few studies reported the onset of SFN after COVID-19 infection and vaccination, investigating the presence of potential antibody targets. Despite these overall findings, the pathogenic role has been demonstrated only for some autoantibodies, and the association with specific clinical phenotypes or response to immunotherapy remains to be clarified. The purpose of this review is to summarise known autoantibody targets involved in neuropathic pain, putative attractive autoantibody targets in iSFN patients, their potential as biomarkers of response to immunotherapy and their role in the development of iSFN.
Collapse
Affiliation(s)
- Luana Morelli
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Via Altura, 3 - 40139, Bologna, Italy
| | - Lucrezia Serra
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Via Altura, 3 - 40139, Bologna, Italy
| | - Fortuna Ricciardiello
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Via Altura, 3 - 40139, Bologna, Italy
| | - Ilaria Gligora
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Via Altura, 3 - 40139, Bologna, Italy
| | - Vincenzo Donadio
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Via Altura, 3 - 40139, Bologna, Italy
| | - Marco Caprini
- Department of Pharmacy and Biotechnology (FaBiT), Laboratory of Human and General Physiology, University of Bologna, Via San Donato, 19/2 - 40126, Bologna, Italy
| | - Rocco Liguori
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Via Altura, 3 - 40139, Bologna, Italy
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Via Altura, 3 - 40139, Bologna, Italy
| | - Maria Pia Giannoccaro
- IRCCS Istituto delle Scienze Neurologiche di Bologna, Via Altura, 3 - 40139, Bologna, Italy
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, Via Altura, 3 - 40139, Bologna, Italy
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Ünlü S, Sánchez Navarro BG, Cakan E, Berchtold D, Meleka Hanna R, Vural S, Vural A, Meisel A, Fichtner ML. Exploring the depths of IgG4: insights into autoimmunity and novel treatments. Front Immunol 2024; 15:1346671. [PMID: 38698867 PMCID: PMC11063302 DOI: 10.3389/fimmu.2024.1346671] [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: 11/29/2023] [Accepted: 02/29/2024] [Indexed: 05/05/2024] Open
Abstract
IgG4 subclass antibodies represent the rarest subclass of IgG antibodies, comprising only 3-5% of antibodies circulating in the bloodstream. These antibodies possess unique structural features, notably their ability to undergo a process known as fragment-antigen binding (Fab)-arm exchange, wherein they exchange half-molecules with other IgG4 antibodies. Functionally, IgG4 antibodies primarily block and exert immunomodulatory effects, particularly in the context of IgE isotype-mediated hypersensitivity reactions. In the context of disease, IgG4 antibodies are prominently observed in various autoimmune diseases combined under the term IgG4 autoimmune diseases (IgG4-AID). These diseases include myasthenia gravis (MG) with autoantibodies against muscle-specific tyrosine kinase (MuSK), nodo-paranodopathies with autoantibodies against paranodal and nodal proteins, pemphigus vulgaris and foliaceus with antibodies against desmoglein and encephalitis with antibodies against LGI1/CASPR2. Additionally, IgG4 antibodies are a prominent feature in the rare entity of IgG4 related disease (IgG4-RD). Intriguingly, both IgG4-AID and IgG4-RD demonstrate a remarkable responsiveness to anti-CD20-mediated B cell depletion therapy (BCDT), suggesting shared underlying immunopathologies. This review aims to provide a comprehensive exploration of B cells, antibody subclasses, and their general properties before examining the distinctive characteristics of IgG4 subclass antibodies in the context of health, IgG4-AID and IgG4-RD. Furthermore, we will examine potential therapeutic strategies for these conditions, with a special focus on leveraging insights gained from anti-CD20-mediated BCDT. Through this analysis, we aim to enhance our understanding of the pathogenesis of IgG4-mediated diseases and identify promising possibilities for targeted therapeutic intervention.
Collapse
Affiliation(s)
- Selen Ünlü
- Koç University Research Center for Translational Medicine (KUTTAM), İstanbul, Türkiye
- Koç University School of Medicine, Istanbul, Türkiye
| | - Blanca G. Sánchez Navarro
- Department of Neurology with Experimental Neurology, Integrated Myasthenia Gravis Center, Neuroscience Clinical Research Center, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Elif Cakan
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA, United States
| | - Daniel Berchtold
- Department of Neurology with Experimental Neurology, Integrated Myasthenia Gravis Center, Neuroscience Clinical Research Center, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Rafael Meleka Hanna
- Department of Neurology with Experimental Neurology, Integrated Myasthenia Gravis Center, Neuroscience Clinical Research Center, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Secil Vural
- Koç University Research Center for Translational Medicine (KUTTAM), İstanbul, Türkiye
- Department of Dermatology and Venereology, Koç University School of Medicine, İstanbul, Türkiye
| | - Atay Vural
- Koç University Research Center for Translational Medicine (KUTTAM), İstanbul, Türkiye
- Department of Neurology, Koç University School of Medicine, İstanbul, Türkiye
| | - Andreas Meisel
- Department of Neurology with Experimental Neurology, Integrated Myasthenia Gravis Center, Neuroscience Clinical Research Center, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Miriam L. Fichtner
- Koç University Research Center for Translational Medicine (KUTTAM), İstanbul, Türkiye
- Department of Neurology with Experimental Neurology, Integrated Myasthenia Gravis Center, Neuroscience Clinical Research Center, Charité Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
5
|
Theorell J, Harrison R, Williams R, Raybould MIJ, Zhao M, Fox H, Fower A, Miller G, Wu Z, Browne E, Mgbachi V, Sun B, Mopuri R, Li Y, Waters P, Deane CM, Handel A, Makuch M, Irani SR. Ultrahigh frequencies of peripherally matured LGI1- and CASPR2-reactive B cells characterize the cerebrospinal fluid in autoimmune encephalitis. Proc Natl Acad Sci U S A 2024; 121:e2311049121. [PMID: 38319973 PMCID: PMC10873633 DOI: 10.1073/pnas.2311049121] [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: 07/02/2023] [Accepted: 12/22/2023] [Indexed: 02/08/2024] Open
Abstract
Intrathecal synthesis of central nervous system (CNS)-reactive autoantibodies is observed across patients with autoimmune encephalitis (AE), who show multiple residual neurobehavioral deficits and relapses despite immunotherapies. We leveraged two common forms of AE, mediated by leucine-rich glioma inactivated-1 (LGI1) and contactin-associated protein-like 2 (CASPR2) antibodies, as human models to comprehensively reconstruct and profile cerebrospinal fluid (CSF) B cell receptor (BCR) characteristics. We hypothesized that the resultant observations would both inform the observed therapeutic gap and determine the contribution of intrathecal maturation to pathogenic B cell lineages. From the CSF of three patients, 381 cognate-paired IgG BCRs were isolated by cell sorting and scRNA-seq, and 166 expressed as monoclonal antibodies (mAbs). Sixty-two percent of mAbs from singleton BCRs reacted with either LGI1 or CASPR2 and, strikingly, this rose to 100% of cells in clonal groups with ≥4 members. These autoantigen-reactivities were more concentrated within antibody-secreting cells (ASCs) versus B cells (P < 0.0001), and both these cell types were more differentiated than LGI1- and CASPR2-unreactive counterparts. Despite greater differentiation, autoantigen-reactive cells had acquired few mutations intrathecally and showed minimal variation in autoantigen affinities within clonal expansions. Also, limited CSF T cell receptor clonality was observed. In contrast, a comparison of germline-encoded BCRs versus the founder intrathecal clone revealed marked gains in both affinity and mutational distances (P = 0.004 and P < 0.0001, respectively). Taken together, in patients with LGI1 and CASPR2 antibody encephalitis, our results identify CSF as a compartment with a remarkably high frequency of clonally expanded autoantigen-reactive ASCs whose BCR maturity appears dominantly acquired outside the CNS.
Collapse
Affiliation(s)
- Jakob Theorell
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OxfordOX3 9DU, United Kingdom
- Department of Medicine Huddinge, Karolinska Institutet, Stockholm17177, Sweden
- Department of Neurology, Karolinska University Hospital, Stockholm17176, Sweden
| | - Ruby Harrison
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OxfordOX3 9DU, United Kingdom
| | - Robyn Williams
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OxfordOX3 9DU, United Kingdom
- Department of Neurology, John Radcliffe Hospital, Oxford University Hospitals, OxfordOX3 9DU, United Kingdom
| | - Matthew I. J. Raybould
- Department of Statistics, Oxford Protein Informatics Group, University of Oxford, OxfordOX1 3LB, United Kingdom
| | - Meng Zhao
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OxfordOX3 9DU, United Kingdom
| | - Hannah Fox
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OxfordOX3 9DU, United Kingdom
| | - Andrew Fower
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OxfordOX3 9DU, United Kingdom
| | - Georgina Miller
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OxfordOX3 9DU, United Kingdom
| | - Zoe Wu
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OxfordOX3 9DU, United Kingdom
| | - Eleanor Browne
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OxfordOX3 9DU, United Kingdom
| | - Victor Mgbachi
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OxfordOX3 9DU, United Kingdom
| | - Bo Sun
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OxfordOX3 9DU, United Kingdom
| | - Rohini Mopuri
- Department of Quantitative Health Sciences, Mayo Clinic, Jacksonville, FL32224
| | - Ying Li
- Department of Quantitative Health Sciences, Mayo Clinic, Jacksonville, FL32224
| | - Patrick Waters
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OxfordOX3 9DU, United Kingdom
| | - Charlotte M. Deane
- Department of Statistics, Oxford Protein Informatics Group, University of Oxford, OxfordOX1 3LB, United Kingdom
| | - Adam Handel
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OxfordOX3 9DU, United Kingdom
- Department of Neurology, John Radcliffe Hospital, Oxford University Hospitals, OxfordOX3 9DU, United Kingdom
| | - Mateusz Makuch
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OxfordOX3 9DU, United Kingdom
| | - Sarosh R. Irani
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OxfordOX3 9DU, United Kingdom
- Department of Neurology, John Radcliffe Hospital, Oxford University Hospitals, OxfordOX3 9DU, United Kingdom
- Departments of Neurology and Neuroscience, Mayo Clinic, Jacksonville, FL32224
| |
Collapse
|
6
|
Yeo T, Chai JYH, Tan K. Response to Letter to Editor 'increased cases of VGKC-complex observed during current COVID-19 pandemic'. J Neurol Sci 2024; 456:122843. [PMID: 38114361 DOI: 10.1016/j.jns.2023.122843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 12/11/2023] [Indexed: 12/21/2023]
Affiliation(s)
- Tianrong Yeo
- Department of Neurology, National Neuroscience Institute, Singapore; Duke-NUS Medical School, Singapore; Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.
| | | | - Kevin Tan
- Department of Neurology, National Neuroscience Institute, Singapore; Duke-NUS Medical School, Singapore
| |
Collapse
|
7
|
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.
Collapse
Affiliation(s)
- Josep Dalmau
- IDIBAPS-Hospital Clinic, University of Barcelona, Barcelona, Spain; Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, Spain.
| |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Qin M, Chen J, Guo X, Xiang X, Nie L, Wang Y, Mao L. Movement disorders in autoimmune encephalitis: an update. J Neurol 2023; 270:5288-5302. [PMID: 37523063 DOI: 10.1007/s00415-023-11881-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 07/13/2023] [Accepted: 07/13/2023] [Indexed: 08/01/2023]
Abstract
Autoimmune encephalitis (AE) is a form of encephalitis resulting from an immune response targeting central nervous system antigens, which is characterized by cognitive impairment, neuropsychiatric symptoms, seizures, movement disorders (MDs), and other encephalopathy symptoms. MDs frequently manifest throughout the progression of the disease, with recurrent involuntary movements leading to discomfort and, in some cases, necessitating admission to the intensive care unit. Prompt identification and management of MDs can aid in the diagnosis and prognosis of AE. This review synthesizes current knowledge on the characteristics, underlying mechanisms, and treatment options for MDs in the context of AE.
Collapse
Affiliation(s)
- Mengting Qin
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jiaojiao Chen
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaoqing Guo
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xuying Xiang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lei Nie
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yong Wang
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Ling Mao
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| |
Collapse
|
11
|
Rada A, Bien CG. What is autoimmune encephalitis-associated epilepsy? Proposal of a practical definition. Epilepsia 2023; 64:2249-2255. [PMID: 37353891 DOI: 10.1111/epi.17699] [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: 04/12/2023] [Revised: 06/21/2023] [Accepted: 06/21/2023] [Indexed: 06/25/2023]
Abstract
Seizures resulting from cerebral autoimmunity are either acutely symptomatic in the context of autoimmune encephalitis (AIE) with neural surface antibodies, or they are indicative of an enduring predisposition to seizures, that is, epilepsy. Here, we propose a practical definition for autoimmune encephalitis-associated epilepsy (AEAE): Seizures associated with antibodies against glutamic acid decarboxylase, paraneoplastic syndromes, or Rasmussen encephalitis are classified as AEAE. AEAE secondary to AIE with antibodies against the N-methyl-D-aspartate receptor, leucine-rich glioma inactivated protein 1, contactin-associated protein-2, or γ-aminobutyric acid-B receptor can be diagnosed if the following criteria are met: seizures persist for at least 2 years after immunotherapy initiation; no signs of encephalitis on magnetic resonance imaging and no fluorodeoxyglucose positron emission tomography hypermetabolism; normal cerebrospinal fluid cell count; and a substantial decrease in antibody titers. This classification corresponds to different disease mechanisms. While AIE results from the pathogenic effects of neural antibodies, AEAE is probably the consequence of encephalitis-related tissue damage and thereby mainly structurally mediated. The distinction between AIE and AEAE also has practical consequences: In AIE, immunotherapy is usually highly beneficial, whereas anti-seizure medication has little effect. In AEAE, immunotherapy is less promising and the usual anti-seizure interventions are preferable. In addition, the diagnosis of AEAE has social consequences in terms of driving and professional limitations.
Collapse
Affiliation(s)
- Anna Rada
- Department of Epileptology (Krankenhaus Mara), Medical School, Bielefeld University, Bielefeld, Germany
| | - Christian G Bien
- Department of Epileptology (Krankenhaus Mara), Medical School, Bielefeld University, Bielefeld, Germany
| |
Collapse
|
12
|
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.
Collapse
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
| |
Collapse
|
13
|
Gövert F, Abrante L, Becktepe J, Balint B, Ganos C, Hofstadt-van Oy U, Krogias C, Varley J, Irani SR, Paneva S, Titulaer MJ, de Vries JM, Boon AJW, Schreurs MWJ, Joubert B, Honnorat J, Vogrig A, Ariño H, Sabater L, Dalmau J, Scotton S, Jacob S, Melzer N, Bien CG, Geis C, Lewerenz J, Prüss H, Wandinger KP, Deuschl G, Leypoldt F. Distinct movement disorders in contactin-associated-protein-like-2 antibody-associated autoimmune encephalitis. Brain 2023; 146:657-667. [PMID: 35875984 DOI: 10.1093/brain/awac276] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 06/02/2022] [Accepted: 06/22/2022] [Indexed: 11/14/2022] Open
Abstract
Autoimmune encephalitis can be classified into antibody-defined subtypes, which can manifest with immunotherapy-responsive movement disorders sometimes mimicking non-inflammatory aetiologies. In the elderly, anti-LGI1 and contactin associated protein like 2 (CASPR2) antibody-associated diseases compose a relevant fraction of autoimmune encephalitis. Patients with LGI1 autoantibodies are known to present with limbic encephalitis and additionally faciobrachial dystonic seizures may occur. However, the clinical spectrum of CASPR2 autoantibody-associated disorders is more diverse including limbic encephalitis, Morvan's syndrome, peripheral nerve hyperexcitability syndrome, ataxia, pain and sleep disorders. Reports on unusual, sometimes isolated and immunotherapy-responsive movement disorders in CASPR2 autoantibody-associated syndromes have caused substantial concern regarding necessity of autoantibody testing in patients with movement disorders. Therefore, we aimed to systematically assess their prevalence and manifestation in patients with CASPR2 autoimmunity. This international, retrospective cohort study included patients with CASPR2 autoimmunity from participating expert centres in Europe. Patients with ataxia and/or movement disorders were analysed in detail using questionnaires and video recordings. We recruited a comparator group with anti-LGI1 encephalitis from the GENERATE network. Characteristics were compared according to serostatus. We identified 164 patients with CASPR2 autoantibodies. Of these, 149 (90.8%) had only CASPR2 and 15 (9.1%) both CASPR2 and LGI1 autoantibodies. Compared to 105 patients with LGI1 encephalitis, patients with CASPR2 autoantibodies more often had movement disorders and/or ataxia (35.6 versus 3.8%; P < 0.001). This was evident in all subgroups: ataxia 22.6 versus 0.0%, myoclonus 14.6 versus 0.0%, tremor 11.0 versus 1.9%, or combinations thereof 9.8 versus 0.0% (all P < 0.001). The small group of patients double-positive for LGI1/CASPR2 autoantibodies (15/164) significantly more frequently had myoclonus, tremor, 'mixed movement disorders', Morvan's syndrome and underlying tumours. We observed distinct movement disorders in CASPR2 autoimmunity (14.6%): episodic ataxia (6.7%), paroxysmal orthostatic segmental myoclonus of the legs (3.7%) and continuous segmental spinal myoclonus (4.3%). These occurred together with further associated symptoms or signs suggestive of CASPR2 autoimmunity. However, 2/164 patients (1.2%) had isolated segmental spinal myoclonus. Movement disorders and ataxia are highly prevalent in CASPR2 autoimmunity. Paroxysmal orthostatic segmental myoclonus of the legs is a novel albeit rare manifestation. Further distinct movement disorders include isolated and combined segmental spinal myoclonus and autoimmune episodic ataxia.
Collapse
Affiliation(s)
- Felix Gövert
- Department of Neurology, Christian-Albrecht University of Kiel and University Medical Center Schleswig-Holstein, 24105 Kiel, Germany
| | - Ligia Abrante
- Neuroimmunology, Institute of Clinical Chemistry, Christian-Albrecht University of Kiel and University Medical Center Schleswig-Holstein, 24105 Kiel, Germany
| | - Jos Becktepe
- Department of Neurology, Christian-Albrecht University of Kiel and University Medical Center Schleswig-Holstein, 24105 Kiel, Germany
| | - Bettina Balint
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK.,Department of Neurology, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Christos Ganos
- Department of Neurology, Charité University Medicine Berlin, 10117 Berlin, Germany
| | | | - Christos Krogias
- Department of Neurology, St Josef Hospital, Ruhr University Bochum, 44791 Bochum, Germany
| | - James Varley
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Sarosh R Irani
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Sofija Paneva
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - Maarten J Titulaer
- Department of Neurology, Erasmus MC University Medical Center, 3015 GD Rotterdam, The Netherlands
| | - Juna M de Vries
- Department of Neurology, Erasmus MC University Medical Center, 3015 GD Rotterdam, The Netherlands
| | - Agnita J W Boon
- Department of Neurology, Erasmus MC University Medical Center, 3015 GD Rotterdam, The Netherlands
| | - Marco W J Schreurs
- Department of Neurology, Erasmus MC University Medical Center, 3015 GD Rotterdam, The Netherlands
| | - Bastien Joubert
- Centre National de Référence pour les Syndromes Neurologiques Paranéoplasiques, Hospices Civils de Lyon, Hôpital Neurologique, 69677 Bron, France.,Institut NeuroMyoGene INSERM U1217/CNRS UMR 5310, Université de Lyon-Université Claude Bernard Lyon 1, Lyon, France
| | - Jerome Honnorat
- Centre National de Référence pour les Syndromes Neurologiques Paranéoplasiques, Hospices Civils de Lyon, Hôpital Neurologique, 69677 Bron, France.,Institut NeuroMyoGene INSERM U1217/CNRS UMR 5310, Université de Lyon-Université Claude Bernard Lyon 1, Lyon, France
| | - Alberto Vogrig
- Centre National de Référence pour les Syndromes Neurologiques Paranéoplasiques, Hospices Civils de Lyon, Hôpital Neurologique, 69677 Bron, France.,Institut NeuroMyoGene INSERM U1217/CNRS UMR 5310, Université de Lyon-Université Claude Bernard Lyon 1, Lyon, France
| | - Helena Ariño
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS); Service of Neurology, Hospital Clínic, University of Barcelona, 08036 Barcelona, Spain
| | - Lidia Sabater
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS); Service of Neurology, Hospital Clínic, University of Barcelona, 08036 Barcelona, Spain
| | - Josep Dalmau
- August Pi i Sunyer Biomedical Research Institute (IDIBAPS); Service of Neurology, Hospital Clínic, University of Barcelona, 08036 Barcelona, Spain.,Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA.,Catalan Institution for Research and Advanced Studies (ICREA), 08010 Barcelona, Spain
| | - Sangeeta Scotton
- Department of Neurology, University Hospitals Birmingham, Birmingham B15 2TH, UK
| | - Saiju Jacob
- Department of Neurology, University Hospitals Birmingham, Birmingham B15 2TH, UK
| | - Nico Melzer
- Department of Neurology with Institute of Translational Neurology, University of Münster, 48149 Münster, Germany.,Department of Neurology, Medical Faculty, Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany
| | - Christian G Bien
- Department of Epileptology (Krankenhaus Mara), Bielefeld University, Medical School, Campus Bielefeld-Bethel, 33617 Bielefeld, Germany
| | - Christian Geis
- Department of Neurology, University of Jena, 07747 Jena, Germany
| | - Jan Lewerenz
- Department of Neurology, Ulm University, 89081 Ulm, Germany
| | - Harald Prüss
- German Center for Neurodegenerative Diseases (DZNE) Berlin and Department of Neurology, Charité Universitätsmedizin Berlin, 10117 Berlin, Germany
| | - Klaus-Peter Wandinger
- Neuroimmunology, Institute of Clinical Chemistry, University Medical Center Schleswig-Holstein, 23538 Lübeck, Germany.,Department of Neurology, University of Luebeck and University Medical Center Schleswig-Holstein, 23538 Lübeck, Germany
| | - Günther Deuschl
- Department of Neurology, Christian-Albrecht University of Kiel and University Medical Center Schleswig-Holstein, 24105 Kiel, Germany
| | - Frank Leypoldt
- Department of Neurology, Christian-Albrecht University of Kiel and University Medical Center Schleswig-Holstein, 24105 Kiel, Germany.,Neuroimmunology, Institute of Clinical Chemistry, Christian-Albrecht University of Kiel and University Medical Center Schleswig-Holstein, 24105 Kiel, Germany
| |
Collapse
|
14
|
Abstract
PURPOSE OF REVIEW Autoimmune neuromyotonia encompasses a group of rare immune-mediated neurological disorders frequently associated with anti-contactin-associated protein-like 2 (CASPR2) antibodies and featuring clinical and electrical signs of peripheral nerve hyperexcitability (PNH). We aim to summarize the current knowledge on immune-mediated neuromyotonia, focusing on clinical presentations, pathophysiology, and management. RECENT FINDINGS Neuromyotonia is a major feature of several autoimmune neurological syndromes characterized by PNH with or without central neurological system involvement. Experimental and clinical evidence suggest that anti-CASPR2 antibodies are directly pathogenic in autoimmune neuromyotonia patients. SUMMARY Neuromyotonia, a form of PNH, is a major feature in several syndromes associated with anti-CASPR2 antibodies, including cramp-fasciculation syndrome, Isaacs syndrome, Morvan syndrome, and autoimmune limbic encephalitis. Diagnosis relies on the identification of motor, sensory, and autonomic signs of PNH along with other neurological symptoms, anti-CASPR2 antibody-positivity, and of characteristic electroneuromyographic abnormalities. Paraneoplastic associations with thymoma are possible, especially in Morvan syndrome. Patients usually respond to immune-active treatments, including steroids, intravenous immunoglobulins, plasma exchanges, and rituximab.
Collapse
Affiliation(s)
- Louis Comperat
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon
| | - Antoine Pegat
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon
- Electroneuromyography and Neuromuscular Diseases Unit, Pierre Wertheimer Hospital, Hospices Civils de Lyon
| | - Jérôme Honnorat
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon
- Synaptopathies and Autoantibodies (SynatAc) Team, Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Université Claude Bernard Lyon 1
| | - Bastien Joubert
- French Reference Center on Paraneoplastic Neurological Syndromes and Autoimmune Encephalitis, Hospices Civils de Lyon
- Synaptopathies and Autoantibodies (SynatAc) Team, Institut NeuroMyoGène, INSERM U1217/CNRS UMR 5310, Université Claude Bernard Lyon 1
- Department of Neurology, Centre Hospitalier Lyon Sud, Hospices Civils de Lyon, Lyon, France
| |
Collapse
|
15
|
Gill AJ, Venkatesan A. Pathogenic mechanisms in neuronal surface autoantibody-mediated encephalitis. J Neuroimmunol 2022; 368:577867. [DOI: 10.1016/j.jneuroim.2022.577867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/22/2022] [Accepted: 04/09/2022] [Indexed: 11/16/2022]
|
16
|
Maudes E, Mannara F, García-Serra A, Radosevic M, Mellado A, Serafim AB, Planagumà J, Sabater L, Dalmau J, Spatola M. Human mGluR5 antibodies alter receptor levels and behavior in mice. Ann Neurol 2022; 92:81-86. [PMID: 35373379 DOI: 10.1002/ana.26362] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/24/2022] [Accepted: 03/26/2022] [Indexed: 11/08/2022]
Abstract
The Ophelia syndrome or encephalitis with antibodies against the metabotropic glutamate receptor 5 (mGluR5) manifests with behavioral changes, memory deficits and anxiety. To study the antibody pathogenicity, mice received continuous cerebroventricular infusion of patients' or controls' IgG for 14 days, followed by a 15-day wash-out. The effects on hippocampal mGluR5 clusters were determined by confocal microscopy. Animals infused with patients' IgG, but not controls' IgG, showed memory impairment, increased anxiety, and decreased neuronal surface mGluR5 clusters. After antibody clearance, both behavioral and molecular changes reversed to baseline conditions. These findings support the pathogenicity of these antibodies in anti-mGluR5 encephalitis. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- Estibaliz Maudes
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Francesco Mannara
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Anna García-Serra
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Marija Radosevic
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Araceli Mellado
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Ana Beatriz Serafim
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Jesús Planagumà
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Lidia Sabater
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Josep Dalmau
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA.,Centro de Investigación Biomédica en Red, Enfermedades Raras (CIBERER), Spain.,Catalan Institute for Research and Advanced Studies (ICREA), Barcelona, Spain
| | - Marianna Spatola
- Neuroimmunology Program, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,Ragon Institute of MGH, MIT and Harvard Medical School, Cambridge, MA, USA
| |
Collapse
|