MOGAD-Like Encephalitic Syndromes Without MOG Antibodies in Children
Year: 2026
Type: article
Study design: Observational Study
Abstract: BACKGROUND AND OBJECTIVES: Although acute disseminated encephalomyelity (ADEM) can be myelin oligodendrocyte glycoprotein-IgG (MOG-IgG) positive or negative, it is unclear whether other MOG-antibody-associated disease (MOGAD)-like encephalitis syndromes occur without MOG-IgG. We aimed to define the frequency, clinico-radiologic features, outcomes, and antibody associations of such cases in children. METHODS: Prospective cohort study of children (<18 years) with encephalitis meeting clinico-radiologic MOGAD criteria, regardless of MOG-IgG status. Serum from all patients and CSF when available were tested by live cell-based assays (CBA-IIF, CBA-FACS) at 2 laboratories. Brain MRIs were centrally reviewed for MOGAD-like patterns (ADEM, cortical encephalitis, isolated/predominant central gray matter). Additional testing included CBAs for MOG-IgA, MOG-IgM, PLP1-IgG, glial fibrillary acidic protein-IgG, and AQP4-IgG, along with rat brain immunohistochemistry. RESULTS: = 0.017). Immunohistochemistry revealed myelin immunostaining in 14 (12%) MOG-IgG-positive cases (CBA confirmed cross-reactivity with rodent MOG-epitopes) and 10 (25%) MOG-IgG-negative patients (no cross-reactivity with rodent MOG-epitopes); this included a fulminant case with autopsy showing perivenous demyelination and C4d complement deposition, suggesting autoantibodies against an unknown myelin antigen. MOG-IgA, MOG-IgM, or PLP1-IgG occurred in 36/111 (32%) MOG-IgG-positive and 7/37 (19%) MOG-IgG-negative cases, without clinical differences between groups. DISCUSSION: Children can develop the full spectrum of MOGAD-like encephalitis without MOG-IgG. Clinical features and immunotherapy response are similar to MOGAD, but relapses are uncommon.
Authors: Gemma Olivé-Cirera, Elianet Gisell Fonseca, Mar Guasp, Ludovica Falcioni, Anna Fetta, Raquel Ruiz García, Elisabet Poyatos, Ana Beatriz Serafim, Maria Gual, Gianni Ippoliti, Armando Reques, Laura Naranjo Rondán, Marianna Spatola, Yolanda Blanco, Eugenia Martinez-Hernandez, Francesc Graus, Maria Sepulveda, Romana Höftberger, Lidia Sabater, Albert Saiz, Josep Dalmau, Thais Armangue, for the Spanish Pediatric Autoimmune Encephalitis study group
Institutions: Hospital de Sant Pau, Consorci Institut D'Investigacions Biomediques August Pi I Sunyer, CaixaResearch Institute, Universitat de Barcelona, Hospital Sant Joan de Déu Barcelona, Centre for Biomedical Network Research on Rare Diseases, University of Sassari, University of Cagliari, Azienda Ospedaliero Universitaria di Sassari, Azienda Ospedaliera G. Brotzu, University of Bologna, Hospital Clínic de Barcelona, Corporació Sanitària Parc Taulí, Universitat Autònoma de Barcelona, Institute of Research and Innovation Parc Tauli, ERN RITA, Medical University of Vienna, University of Pennsylvania
Language: English
Subfield: Pathology and Forensic Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,450
Awards: G2819199708, Factores predictores, nuevos biomarcadores y anticuerpos involucrados en enfermedades desmielinizantes infantiles, Impact of IgLON5 on cerebellar circuits and pathology, Déficits neuropsiquiátricos y cognitivos y el papel de la disfunción del sistema inmunitario adaptativo en la fase post-aguda de la encefalitis anti-NMDAR, G8983143547
OpenAlex ID: W7204100224