Year: 2026
Type: article
Study design: Observational Study
Abstract: BACKGROUND AND OBJECTIVES: Distinguishing multiple sclerosis (MS) from myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) can be challenging because of some shared clinical and radiologic features. We aimed to describe adults with clear positive serum MOG antibodies (MOG-Abs) presenting with MS features and rethink their nosological framework. METHODS: We conducted a retrospective longitudinal study within the French NOMADMUS cohort and included adults from 2015 to 2025 tested clear positive for MOG-Ab in the serum with at least 1 MS-suggestive feature: (1) biological (CSF-specific oligoclonal bands [OCBs] and/or kappa free light chain index [KFLCi] ≥5.7) or (2) radiologic (≥1 lesion among juxtacortical lesion, Dawson finger, or inferior temporal lobe lesion). All MRI scans were reviewed blindly by an expert neuroradiologist. Minimum clinical and radiologic follow-up was 6 months. We classified patients as (1) typical MS when fulfilling 2024 McDonald criteria, with OCB and/or KFLCi ≥5.7 and showing no MOGAD supporting features, or (2) equivocal in all other situations. RESULTS: Among the 78 included patients (65% female, median age: 35 years), 23% were classified as typical MS and 77% as equivocal; all met MOGAD criteria, and 76% met 2024 McDonald criteria, without using central veinous sign or paramagnetic rim lesion, which have been rarely assessed. Myelitis followed by optic neuritis constituted the predominant clinical presentations in the whole cohort (45% and 32%, respectively) and in both groups. For typical MS cases, half of the patients did not receive maintenance therapy after the first MOG-Ab-positive event, 28% relapsed, 55% developed new silent lesions, and none showed lesion resolution (median follow-up: 1.9 years). For equivocal patients, 84% had OCB and 88% had ≥1 MOGAD supporting feature. After the first MOG-Ab-positive event, 72% initiated a maintenance therapy-mostly rituximab-15% relapsed, 46% developed silent new lesions, and 23% showed complete resolution of ≥1 lesion (median follow-up: 3 years). DISCUSSION: Clear positive MOG-Ab may occur in patients with genuine MS, and their presence may lead to therapeutic inertia. The substantial proportion of equivocal cases highlights current diagnostic limitations and underscores the need for longitudinal clinical and radiologic reassessment.
Authors: Jeanne Garcia, Natalia Shor, Clemence Boutiere, Julie Pique, Marine Boudot De La Motte, Maxime Guillaume, Adrien Delourme, Helene Zephir, Jonathan Ciron, Clarisse Carra-Dalliere, Pauline Buissonnière, Nicolas Mélé, Jennifer Aboab, Mikael Cohen, Adrien Wang, Justine Couturier, Diana Rusu, Eric Thouvenot, David Axel Laplaud, Aurélie Ruet, Bertrand Bourre, Françoise Durand-Dubief, Lakhdar Benyahya, Nicolas Collongues, Laure Michel, Romain Deschamps, Caroline Papeix, Bertrand Audoin, Bruno Stankoff, Valerie Touitou, Catherine Vignal Clermont, Delphine Sterlin, Romain Marignier, Elisabeth Maillart, for the NOMADMUS study group
Institutions: Assistance Publique – Hôpitaux de Paris, Pitié-Salpêtrière Hospital, Centre National de la Recherche Scientifique, Inserm, Sorbonne Université, Institut du Cerveau, Hôpital de la Timone, Hospices Civils de Lyon, Observatoire Français de la Sclérose en Plaques, Université Paris Cité, Hôpital Rothschild, Fondation de Rothschild, Centre Hospitalier Universitaire de Rouen, Princess Grace Hospital Centre, Université de Lille, Centre Hospitalier Universitaire de Lille, Lille Neurosciences & Cognition, Université Toulouse III - Paul Sabatier, Centre Hospitalier Universitaire de Toulouse, Institut Toulousain des Maladies Infectieuses et Inflammatoires, Université de Toulouse, Centre Hospitalier Universitaire de Montpellier, Centre Hospitalier Universitaire de Bordeaux, Centre Hospitalier Sainte-Anne, Institut de Psychiatrie et Neurosciences de Paris, GHU Paris psychiatrie & neurosciences, Université Côte d'Azur, Centre Hospitalier Universitaire de Nice, Hôpital Pasteur, Hôpital Foch, Centre Hospitalier Universitaire de Nantes, Center for Research in Transplantation and Translational Immunology, Nantes Université, Institut de Génomique Fonctionnelle, Neurocentre Magendie, Lyon 1 Université, Hôpitaux Universitaires de Strasbourg, CIC Rennes, Centre Hospitalier Universitaire de Rennes, Microenvironment and B-cells: Immunopathology, Cell, Differentiation and Cancer
Language: English
Subfield: Clinical Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,450
Funder: Agence Nationale de la Recherche
OpenAlex ID: W7223216327