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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Phenotypic analysis of the Plp-deficient mouse

Yool, Donald Andrew January 2000 (has links)
No description available.
2

Oligodendroglial anillin facilitates septin assembly to prevent myelin outfoldings

Erwig, Michelle Scarlett 28 January 2019 (has links)
No description available.
3

Imunologický profil experimentální autoimunitní encefalomyelitidy. / Immunologic profile of experimental autoimmune encephalomyelitis

Novosádová, Iva January 2012 (has links)
5 Anglický abstrakt Experimental autoimmune encephalomyelitis (EAE) is widely accepted as a murine model of human multiple sclerosis autoimmune disease. Murine EAE is usually actively induced by immunization with a suitable myelin antigen. Following immunization, CD4+ T helper lymphocytes Th1 and Th17 accumulate in the nervous tissue and via the production of cytokines, they mediate an inflammatory reaction and the subsequent destruction of myelin. The main goal of this study was the induction of EAE with clinically observable symptoms and the observation of changes in the counts and phenotypes of cells, mainly NK and T cells. NK cells express a wide range of inhibitory and activation receptors from the C-lectin-like receptor superfamily. The specific ligand of the activating NKR-P1C isoform is still unknown and thus this receptor's involvement in EAE was also observed. Another goal was the use of medication with regard to the disease progress improvement. For the purposes of this study, two inbred murine strains with distinct NKR-P1 surface expression were used - the SJL/J strain (expressing inhibitory NKR-P1B) and C57BL/6 (expression activating NKR-P1C). SJL mice elicited a relapse-remitting of EAE, while C57BL/6 had chronic EAE. Both mouse strains exerted changes in the counts of NK...
4

Avaliação da cinética da neurite óptica em modelo animal de encefalomielite autoimune experimental induzido por duas diferentes concentrações de glicoproteína dos oligodendrócitos da mielina

Soares, Rubens Murilo Gibaile 19 June 2013 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-05-06T14:33:30Z No. of bitstreams: 1 rubensmurilogibailesoares.pdf: 2619186 bytes, checksum: a84a49cdc9fab5886335802ef1c22da4 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-06-07T16:00:23Z (GMT) No. of bitstreams: 1 rubensmurilogibailesoares.pdf: 2619186 bytes, checksum: a84a49cdc9fab5886335802ef1c22da4 (MD5) / Made available in DSpace on 2016-06-07T16:00:23Z (GMT). No. of bitstreams: 1 rubensmurilogibailesoares.pdf: 2619186 bytes, checksum: a84a49cdc9fab5886335802ef1c22da4 (MD5) Previous issue date: 2013-06-19 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / O modelo de Encefalomielite Autoimune Experimental (EAE) é o mais utilizado no estudo da neurite óptica. Este trabalho tem como objetivo avaliar a cinética da neurite óptica em modelo animal de EAE induzido por duas diferentes concentrações de Glicoproteína dos Oligodendrócitos da Mielina (MOG). Para a indução da EAE foram utilizadas fêmeas de camundongos da linhagem C57BL/6, divididas em dois grupos, um grupo induzido com 100 μg de MOG35-55 e um segundo grupo induzido com 300 μg de MOG35-55. Os animais foram diariamente avaliados por meio da análise do escore clínico entre os dias zero e 58 pós-imunização. Nos dias 7, 10, 14, 21 ou 58 pósimunização, os animais foram submetidos a eutanásia, e os nervos ópticos, dissecados em seu trajeto desde a parte posterior do globo ocular até o quiasma óptico. Posteriormente, foram avaliados os aspectos morfológico e imuno-histoquímico dos nervos ópticos. As alterações histopatológicas observadas em um ou em ambos os nervos ópticos consistiram de infiltrado celular inflamatório, tendo a neurite óptica gravidade diferente nos dois grupos estudados. A quimiocina CCL5 foi avaliada no dia 10 pós-imunização, primeiro dia em que foi detectado o infiltrado inflamatório. Os resultados sugerem que duas diferentes concentrações de MOG35-55 utilizadas na indução do modelo animal de EAE induzem duas diferentes formas de evolução da neurite óptica. / The model of Experimental Autoimmune Encephalomyelitis (EAE) is the most used model in the study of optic neuritis. This study aims to evaluate the kinetics of optic neuritis in the EAE animal model induced by two different concentrations of Oligodendrocytes Myelin Glycoprotein (MOG). For induction of EAE were used female mice of the C57BL/6 lineage, divided into two groups, one group induced with 100 μg of MOG35-55 and a second group induced with 300 μg of MOG35-55. The animals were evaluated daily by analysis of clinical score between zero and 58 days after immunization. On days 7, 10, 14, 21 or 58 post-immunization, the animals were euthanized. The optic nerves were dissected from the back of the eyeball to the optic chiasm; subsequently the morphological and immunohistochemical aspects of the optic nerves were evaluated. The histopathological changes observed in one or in both optic nerves consisted of inflammatory cell infiltrate. Optic neuritis had different levels of severity in the two groups. The chemokine CCL5 was evaluated on day 10 post-immunization, the first day when the inflammatory infiltrate was detected. The results suggest that two different concentrations of MOG35-55 used in the induction of EAE animal model induce two different forms of optic neuritis evolution.
5

Estudo longitudinal dos aspectos clínicos, laboratoriais e imagenológicos de pacientes MOG-IgG positivo / Longitudinal study of clinical, laboratorial and imaging aspects of MOG-IgG positive patients

Salles, Luana Michelli Oliveira de Paula 28 February 2019 (has links)
Introdução: A doença associada ao anticorpo MOG-IgG tem sido reconhecida como uma entidade clínica distinta de neuromielite óptica (NMO) e esclerose múltipla (EM). As principais apresentações clínicas associadas ao MOG-IgG são neurite óptica (NO), mielite e encefalite. Apesar das crescentes evidências na literatura, o papel da análise longitudinal de MOG-IgG ainda não é conhecido. Os objetivos deste estudo foram 1) descrever os aspectos clínicos, laboratoriais e imagenológicos dos pacientes MOG-IgG positivo; 2) estudar as diferenças clínicas e laboratoriais entre os pacientes MOG-IgG com curso monofásico e recorrente; 3) analisar a existência de fatores preditores de recorrência de surtos; 4) investigar se a persistência de MOG-IgG determina doença recorrente; 5) comparar as características clínicas e laboratoriais de pacientes MOG-IgG com pacientes NMOSD AQP4-IgG positivo e negativo. Casuística e métodos: após avaliação de elegibilidade de 574 sujeitos, foram incluídos 31 pacientes MOG-IgG positivos. Estes pacientes foram divididos em dois grupos segundo o padrão de surto, monofásico ou recorrente. Os pacientes foram acompanhados por dois anos em consulta clínica semestral e coleta anual de amostra de sangue para avaliação de MOG-IgG e AQP4-IgG. Resultados: neurite óptica (NO) foi frequente em ambos os grupos sem diferença significativa. Mielite foi encontrada em maior proporção nos pacientes recorrentes, porém sem significância estatística. NO acarretou maior risco para novos surtos, RC= 3,66 (IC 95 % 1,03- 29,91) (p 0,048). Após um primeiro surto de NO, existe uma probabilidade de 75% de que o segundo surto seja também NO. A mesma análise foi realizada para pacientes com mielite no primeiro surto, com uma probabilidade de 80% de mielite no segundo surto. A mediana de EDSS foi maior no grupo de pacientes recorrentes, sendo a diferença significativa entre o grupo recorrente e monofásico (p 0,013). A doença associada ao MOG-IgG possui bom prognóstico com melhora significante de EDSS e acuidade visual (AV) no desfecho quando comparados aos do evento inicial. O desfecho de AV não se correlacionou diretamente com número de episódios de NO. O tratamento imunossupressor profilático reduziu de forma significativa a ocorrência de surtos (p < 0,001). Na análise longitudinal de sorologias de MOG-IgG, a permanência de MOG-IgG esteve associada à atividade clínica de doença e o tratamento imunossupressor reduziu de forma significativa a taxa de amostras positivas. Altos títulos de MOG-IgG tiveram correlação com maior número de surtos de neurite óptica. As sorologias de pacientes com curso monofásico se tornaram negativas ao longo do seguimento clínico, e pacientes recorrentes em remissão clínica também apresentaram menor proporção de amostras positivas / Introduction: The MOG-IgG-associated disease has been recently recognized as different from multiple sclerosis and neuromyelitis optica spectrum disorders. The main phenotypes associated with MOG-IgG are optic neuritis, myelitis and encephalitis. Although there is a growing body of evidence in the literature, the role of longitudinal MOG-IgG analysis is still unknown. The objectives of this study were: 1) to describe clinical and laboratorial aspects of MOG-IgG positive patients; 2) to study the differences between monophasic and relapsing group in clinical and laboratorial aspects; 3) to analyze predictors factors associated with risk of recurrence; 4) to investigate if the persistence of MOG-IgG is associated with risk of relapses; 5) to compare clinical and laboratorial aspects of MOG-IgG patients with NMOSD AQP4-IgG positive and negative patients. Methods: After assessment of eligibility in 574 subjects, 31 patients have been included. These patients have been divided in two groups, according to the course of the disease, if monophasic or relapsing. They have been followed for two years. During this period, annual blood samples have been collected to detect MOG-IgG and AQP4-IgG. Results: optic neuritis (ON) phenotype was frequent in both, monophasic and relapsing group; there were no statistically significant differences between them. Myelitis predominates in the relapsing group, with no significance though. The risk of recurrence is increased by having ON OR 3,66 (CI 95 % 1,03- 29,91) (p 0,048). In a logistic regression analysis, when the patient had ON in the first attack, we found a 75 % probability of having ON in the second attack. When analyzing myelitis, the risk of having a second myelitis as a phenotype was 80%. There were significant differences in EDSS scores between monophasic and relapsing patients (p 0,013). Good outcomes have been found when evaluating EDSS scores and visual acuity at the last visit. Immunossupressor treatment has significantly reduced the number of relapses (p < 0,001). When analyzing longitudinal MOG-IgG samples, relapses have been associated with positive serostatus and the immunosuppressor treatment has significantly reduced the proportion of MOG-IgG positivity. High MOG-IgG titers have been associated with higher proportion of optic neuritis relapses. Monophasic patients became MOG-IgG negative during follow-up, as well as relapsing patients on clinical remission
6

Antigen-specific depletion of autoreacitve B cells in multiple sclerosis

Lamprecht, Chris 31 January 2023 (has links)
Die Entwicklung von Autoimmunerkrankungen wird durch eine Vielzahl verschiedener Faktoren verursacht, darunter gewisse Umwelteinflüsse, genetische Veranlagungen oder Virusinfektionen. So vielfältig die Ursprünge von Autoimmunerkrankungen sind, so divers sind die daraus resultierenden Erkrankungen, wodurch die Entwicklung zuverlässiger Therapien erschwert wird. Obwohl verschiedene Behandlungsmöglichkeiten existieren, welche die Symptome bei Autoimmunerkrankungen wie neuroinflammatorischer Multipler Sklerose (MS) mildern können, z.B. mit monoklonalen Antikörpern (mAk), wirken die meisten Medikamente breit und unspezifisch. Dies beeinträchtigt die Funktionalität des Immunsystems, was wiederum zu einem höheren Risiko für bakterielle und virale Infektionen, maligne Erkrankungen oder sekundäre Autoimmunität führen kann. Andere Therapieansätze untersuchen daher Möglichkeiten einer Antigen-abhängigen Immuntoleranz-Induktion. Allerdings befinden sich diese noch in den frühen Entwicklungsphasen und deren klinische Wirksamkeit muss noch bewiesen werden. Alternativ hat es sich in der onkologischen Immuntherapie als erfolgreich erwiesen, entweder natürliche oder gentechnisch veränderte Immunzellen zu aktivieren. Bisher wurden humane T-Zellen, welche mit Hilfe chimärer Antigenrezeptoren (CAR) mit ausgewählter Spezifität ausgestattet sind, sehr erfolgreich in der Klinik gegen Tumorerkrankungen genutzt. Basierend auf diesen klinischen Erfolgen stellt sich die Frage, ob CAR T-Zellen auch zur Behandlung von Autoimmunerkrankungen eingesetzt werden können. Herkömmlichen CAR T-Zellen mangelt es jedoch sowohl an Flexibilität als auch an Kontrollierbarkeit, da sie mit einem CAR gegen ein einzelnes Antigen ausgestattet sind und in Gegenwart des Zielantigens dauerhaft aktiviert und nicht kontrollierbar sind. Um Limitationen konventioneller CARs zu überwinden, wurden universelle Adapter-CARs (UniCARs, RevCARs) in der Gruppe von Prof. Bachmann entwickelt. Die modulare UniCAR-Plattform besteht aus universell einsetzbaren UniCAR T-Zellen und anpassbaren antigenspezifischen Zielmodulen (TMs). Die Bindungseinheit des UniCAR basiert auf einem mAk mit Spezifität gegen ein Peptidepitop, das Teil des TMs ist und welches spezifisch an Zielantigene auf Tumorzellen bindet. Das TM fungiert als Adaptermolekül, das eine Vernetzung der UniCAR T-Zelle mit der Zielzelle herstellt. Nach der Vernetzung mit der Zielzelle über das TM wird die UniCAR T-Zelle aktiviert, so dass die Zielzelle eliminiert wird. Eine vor Kurzem vorgenommene Modifikation der extrazellulären UniCAR-Domäne führte zu der Reverse CAR (RevCAR)-Plattform, welche die Spezifität und Sicherheit noch weiter erhöhen sowie tonische Signale konventioneller CARs reduzieren soll. Dabei wurde die extrazelluläre mAk-basierte UniCAR-Domäne mit dem Peptidepitop des TM ausgetauscht. Eines der am besten untersuchten Autoantigene bei neuroinflammatorischen Erkrankungen ist das Myelin-Oligodendrozyten-Glykoprotein (MOG). Dieses Protein befindet sich ausschließlich im zentralen Nervensystem an der abaxonalen Membran der nervenschützenden Myelinscheide. Obwohl neuroinflammatorische Erkrankungen wie MS hauptsächlich durch T-Zellen verursacht werden, wurden bei MS-Patienten auch Autoantikörper gegen MOG nachgewiesen, was auf die Beteiligung autoreaktiver B-Zellen an der Verschlimmerung der Krankheit hinweist. Diese Ergebnisse werden durch die wirksame Behandlung von MS-Patienten mit anti-CD20-mAks belegt. In dieser Arbeit wurde MOG als erstes Modell-Zielantigen für das Retargeting von CAR-modifizierten T-Zellen gegen anti-MOG-Ak-exprimierende humane Zellen verwendet. Ziel dieser Arbeit war neue TMs basierend auf der extrazellulären Domäne des MOG Antigens zu entwickeln, die dazu dienen, UniCAR oder RevCAR T-Zellen zur Eliminierung von anti-MOG Ak-exprimierenden Zielzellen zu aktivieren. Zur Bestimmung des optimalen MOG-Antigen TM-Formats wurden für die UniCAR-Plattform ein monovalentes (25 kDa) und ein bivalentes MOG-Antigen TM (50 kDa) entwickelt. Die Wirksamkeit des UniCAR-Systems wurde in vitro demonstriert. Es konnte dabei gezeigt werden, dass beide TMs bereits nach einer kurzen Inkubationszeit von 8 Stunden eine TM-spezifische Lyse Anti-MOG scFv-exprimierender menschlicher Zelllinien durch UniCAR-T-Zellen vermitteln. Darüber hinaus war es möglich, das zytotoxische Potential der UniCAR-T-Zellen durch die Dosierung der TMs zu kontrollieren. Um zu überprüfen, ob der Effekt basierend auf der UniCAR-Platform gegen anti-MOG scFv-exprimierende Zielzellen noch gesteigert werden kann, wurde ein monovalentes MOG-Antigen RevTM für die RevCAR-Plattform entwickelt. In Kombination mit RevCAR-T-Zellen übertraf die Anwendung des RevTM beide UniCAR TMs hinsichtlich Bindungsaffinität und dosisabhängiger Zytotoxizität gegen zwei anti-MOG scFv-exprimierende Zelllinien in vitro. Außerdem war die Freisetzung proinflammatorischer und T-Zellwachstum-fördernder Zytokine im Vergleich zu UniCAR T-Zellen höher und ausgeprägter. Weiterhin wurde die Funktionalität des RevCAR-Systems gegen anti-MOG-scFv-exprimierende Zielzellen in vivo bewiesen. Zusammenfassend kann geschlussfolgert werden, dass die modularen Adapter-CAR T-Zell-Plattformen neben der Krebsimmuntherapie auch bemerkenswertes Potential für die Behandlung von MOG-assoziierten Autoimmunerkrankungen hat. Damit konnte ein erster Grundstein dafür gelegt werden, CAR T-Zellen auf die Anwendung in Autoimmunerkrankungen zu übertragen, um zukünftig gezielt fehlerhafte Immunzellen zu beseitigen, die nachweislich zur Verschlimmerung von Autoimmunerkrankungen beitragen.:Table of contents I List of abbreviations VI 1 Introduction 1 1.1 The human immune system 2 1.2 B cells and antibodies 3 1.2.1 Antibody structure 3 1.2.2 Tolerance induction 4 1.2.3 B cell activation 5 1.2.4 B cell functions in autoimmune diseases 6 1.3 Multiple sclerosis – an example for neuroinflammatory demyelination diseases 8 1.3.1.1 Disease phenotypes 9 1.3.1.2 Immunopathogenesis 9 1.3.2 Autoantigen myelin oligodendrocyte glycoprotein 11 1.4 Immunotherapy 14 1.4.1 Monoclonal antibody therapy 14 1.4.2 Chimeric antigen receptor therapy 16 1.4.2.1 UniCAR and RevCAR T cell system 18 1.4.2.2 CAR T cells in autoimmune diseases 22 1.5 Objectives 23 2 Materials and Methods 25 2.1 Materials 25 2.1.1 Consumables 25 2.1.2 Devices and software 27 2.1.3 Chemicals and reagents 32 2.1.4 Buffers and solutions 36 2.1.5 Enzymes and enzyme buffers 38 2.1.6 Kit systems 39 2.1.7 Plasmid vectors 39 2.1.8 Oligonucleotides 41 2.1.9 Antibodies 41 2.1.10 Basic media, additives, and recombinant proteins 43 2.1.11 Composition of culture media 44 2.1.12 Bacterial strain 46 2.1.13 Cell lines 46 2.1.14 Mouse strain 47 2.2 Methods 47 2.2.1 Molecular biological and microbiology methods 47 2.2.1.1 DNA digestion with restriction enzymes 47 2.2.1.2 Dephosphorylation of vectors 48 2.2.1.3 Agarose gel electrophoresis 48 2.2.1.4 Isolation and purification of DNA fragments from agarose gels 48 2.2.1.5 Ligation of DNA fragments 49 2.2.1.6 Heat-shock transformation of competent E. colis 49 2.2.1.7 Plasmid mini preparation 49 2.2.1.8 Plasmid midi preparation 50 2.2.1.9 Determination of DNA concentration 50 2.2.1.10 DNA sequencing 50 2.2.2 Cell biology methods 50 2.2.2.1 Cultivation of eukaryotic cells 50 2.2.2.2 Freezing and thawing cultured cells 51 2.2.2.3 Determination of cell number 52 2.2.2.4 Lentiviral transduction of eukaryotic cells 52 2.2.2.5 Immunofluorescence labeling 54 2.2.2.6 Flow cytometry and analysis of flow cytometry data 55 2.2.2.7 Isolation of human peripheral blood mononuclear cells 57 2.2.2.8 Isolation of T cells from PBMCs with magnetic-activated cell sorting 58 2.2.2.9 Stimulation of isolated human T cells 58 2.2.2.10 Engraftment of T cells with chimeric antigen receptors 59 2.2.3 Methods of protein biochemistry 59 2.2.3.1 Isolation of target module constructs 59 2.2.3.2 Dialysis of purified target module constructs 60 2.2.3.3 Discontinuous Sodium dodecyl sulfate polyacrylamide gel electrophoresis 60 2.2.3.4 Determination of concentration and immunochemical detection of target module constructs 62 2.2.3.5 Determination of binding affinities of target modules using enzyme-linked immunosorbent assay 63 2.2.4 In vitro functional studies 64 2.2.4.1 T cell activation and exhaustion assay 65 2.2.4.2 Luciferase assay (cytotoxicity assay) 65 2.2.4.3 Determination of cytokine concentration 65 2.2.5 In vivo functionality studies 66 2.2.5.1 Evaluation of tumor killing in vivo 66 2.2.5.2 Optical imaging of luciferase-expressing tumors in vivo 67 2.2.6 Statistical evaluation 67 3 Results 68 3.1 Design and generation of novel MOG target modules 68 3.1.1 MOG target module constructs 68 3.1.2 Expression of target modules 69 3.2 Establishment of scFv MOG-presenting cell models 72 3.3 Binding properties of MOG target modules 74 3.3.1 Determination of binding affinity between anti-MOG antibody and MOG target modules with enzyme-linked immunosorbent assay 74 3.3.2 Determination of binding affinity between anti-MOG receptor-expressing cell lines and MOG target modules with flow cytometry 75 3.4 Generation of human CAR-expressing T cells and binding of MOG target modules 80 3.4.1.1 Genetic modification of human T cells for UniCAR expression 81 3.4.1.2 Genetic modification of human T cells for RevCAR expression 83 3.5 Redirection of UniCAR T cells in vitro 85 3.5.1 Activation of redirected UniCAR T cells 85 3.5.2 Cytokine profile of redirected UniCAR T cells 87 3.5.3 Elimination of scFv MOG-positive target cells by UniCAR T cells 89 3.5.3.1 Time-dependent retargeting of scFv MOG-positive target cells by UniCAR T cells 89 3.5.3.2 Efficacy of UniCAR target modules 91 3.6 Redirection of RevCAR T cells in vitro 92 3.6.1 Activation of redirected RevCAR T cells 92 3.6.2 Cytokine profile of redirected RevCAR T cells 95 3.6.3 Elimination of scFv MOG-positive target cells by RevCAR T cells 99 3.6.3.1 Time-dependent retargeting of scFv MOG-positive target cells using RevCAR T cells 99 3.6.3.2 Efficacy of RevCAR target module 101 3.7 Investigation of RevCAR T cell-mediated cytotoxicity in vivo 103 4 Discussion 105 4.1 Structure and purification of MOG target modules 106 4.2 Expression and purification of target modules 107 4.3 Binding properties of MOG target modules 107 4.4 In vitro cytotoxic potential of UniCAR and RevCAR T cells redirected by MOG target modules 110 4.4.1 Target module-specific redirection of UniCAR T cells to scFv MOG-expressing target cells 110 4.4.2 Target module-specific redirection of RevCAR T cells to scFv MOG-expressing target cells 112 4.5 Future prospective 116 5 Summary 119 6 Zusammenfassung 121 7 References 124 List of figures 145 List of tables 147 Acknowledgement 148
7

Characterization of the neuronal proteolipids M6A and M6B and the oligodendroglial tetraspans PLP and TSPAN2 in neural cell process formation / Charakterisierung der neuronalen Proteolipide M6A und M6B und der oligodendroglialen Viertransmembranproteine PLP und TSPAN2 in der Bildung von neuralen zellulären Fortsätzen

Monasterio Schrader, Patricia Irene de 20 July 2011 (has links)
No description available.
8

Étude comparative des lésions cérébrales dans deux maladies démyélinisantes pédiatriques récurrentes : la sclérose en plaques et la maladie associée aux anticorps anti- glycoprotéine oligodendrocytique de myéline

Mahmoud, Sawsan 07 1900 (has links)
Les syndromes démyélinisants acquis (SDA) pédiatriques sont un groupe de maladies qui affectent la substance blanche (SB) et la substance grise (SG) du système nerveux central (SNC) chez les enfants, et qui partagent certaines caractéristiques et mécanismes pathologiques. Les SDA peuvent être monophasiques ou récurrents. Les SDA comprennent des maladies telles que l'encéphalomyélite aiguë disséminée (EMDA), les troubles du spectre de la neuromyélite optique (TS-NMO), la sclérose en plaques (SEP) et le syndrome démyélinisant récurrent avec anticorps contre la glycoprotéine oligodendrocytique de myéline (anticorps anti-MOG). Ce dernier syndrome, appelé aussi maladie MOG+, a été reconnu récemment comme une entité distincte faisant partie des maladies démyélinisantes récurrentes chez les enfants. La maladie MOG+ présente des caractéristiques semblables à celles de la SEP; en effet, certains cas ont été déjà considérés comme une forme « atypique » de SEP. La maladie MOG+ et la SEP partagent des lésions dans la SB du SNC, mais la SEP est caractérisée aussi par des lésions corticales (LCs) cérébrales, insuffisamment étudiées dans la maladie MOG+. Par conséquent, le but de cette recherche a été de comparer les caractéristiques démographiques et des lésions cérébrales visibles sur des études d’imagerie par résonance magnétique (IRM) chez les enfants atteints de SEP et ceux atteints de la maladie MOG+. Pour atteindre cet objectif, nous avons utilisé des scans IRM 3T, incluant les contrastes pondérés T1, FLAIR et des images de transfert de magnétisation (ITM) de 14 enfants atteints de SEP et 13 enfants atteints de la maladie MOG+. Nous avons mesuré le nombre des LCs, le volume des lésions dans la SB et les valeurs normalisées d’ITM dans les LCs et les lésions de la SB. Nos résultats ont montré que les enfants atteints de la maladie MOG+ étaient plus jeunes au début de la maladie et que celle-ci présentait une durée plus longue que la maladie du groupe SEP. Quant aux lésions cérébrales, les LCs étaient présentes dans la maladie MOG+, mais leur nombre était significativement plus élevé dans le groupe SEP. Cependant, les valeurs normalisées d’ITM dans ces lésions (valeurs qui sont sensibles à la quantité de myéline) n'étaient pas significativement différentes entre les deux groupes. En plus, le volume des lésions de la SB était significativement plus élevé dans le groupe SEP et les valeurs normalisées d’ITM dans ces lésions, significativement inférieures comparativement à la maladie MOG+, témoignant ainsi d’une démyélinisation plus sévère et des différences potentielles dans les mécanismes de démyélinisation. / Pediatric Acquired Demyelinating Syndromes (ADS) are a group of diseases that affect the white matter (WM) and gray matter (GM) of the central nervous system (CNS) in children and that share similar pathological characteristics and mechanisms. ADS can be monophasic or recurrent. The ADS include diseases like acute disseminated encephalomyelitis (ADEM), neuromyelitis optic spectrum disorders (NMO-SD), multiple sclerosis (MS) and Relapsing Myelin Oligodendrocyte Glycoprotein (MOG) syndrome or MOG+ disease, which has been recently recognised as a distinct pathology and is part of the relapsing ADS in children. MOG+ disease shares features with MS; indeed, some MOG+ cases have been considered as an “atypical” form of MS until recently. Both MOG+ disease and MS present lesions in the WM of the CNS. MS is also characterized by focal brain cortical lesions (CL), which have not been extensively studied in MOG+ disease yet. For this reason, the aim of this research project was to compare the demographic and brain magnetic resonance imaging (MRI) characteristics of children with MS and children with MOG+ disease. To achieve our goal, we used 3T MRI including T1-weighted, FLAIR and magnetization transfer ratio (MTR) contrasts of 14 MS participants, and 13 relapsing MOG+ participants. CL counts, WM lesion volumes, normalized MTR values in CLs, and WM lesions were compared across groups. Our results show that children with MOG+ disease were younger at disease onset and had a longer disease duration compared to the MS group. CL were present in MOG+ participants, but counts were significantly higher in the MS group. However, their normalized-MTR values, which are sensitive to myelin, were not significantly different between both groups. WM lesion volumes were significantly higher in the MS group, but their normalized MTR values were significantly lower than in MOG+ WM lesions, likely reflecting more severe demyelination and potential differences in the demyelinating mechanism.

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