101. GABAA receptor autoimmunity: a multicenter experience
- Author
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Bianca Teegen, Chu Yueh Guo, Sean J. Pittock, Lars Komorowski, Jeffrey M. Gelfand, Christian Probst, Patrick Waters, V Mgbachi, Kevin C. O’Connor, Michael D. Geschwind, Anastasia Zekeridou, Swantje Mindorf, Vanda A. Lennon, and Andrew McKeon
- Subjects
0301 basic medicine ,Refractory seizures ,medicine.medical_specialty ,medicine.disease_cause ,Gastroenterology ,Immunoglobulin G ,Autoimmunity ,03 medical and health sciences ,0302 clinical medicine ,Atrophy ,Internal medicine ,medicine ,Indirect immunofluorescence ,biology ,GABAA receptor ,business.industry ,Clinical course ,medicine.disease ,3. Good health ,030104 developmental biology ,Neurology ,biology.protein ,Neurology (clinical) ,business ,030217 neurology & neurosurgery ,Encephalitis - Abstract
ObjectiveWe sought to validate methods for detection and confirmation of GABAA receptor (R)-IgG and clinically characterize seropositive cases.MethodsArchived serum and CSF specimens (185 total) suspected to harbor GABAAR-IgG were evaluated by indirect immunofluorescence assay (IFA). Twenty-six specimens from 19 patients appeared suspicious for GABAAR–IgG positivity by IFA, based on prior reports and comparison with commercial GABAAR antibody staining. Aliquots of those specimens were tested at the University of Oxford, United Kingdom, and Euroimmun, Lubeck, Germany, for GABAAR-IgG by cell-based assays (CBAs) using HEK293-indicator cells transfected with plasmids encoding different GABAAR subunits.ResultsEight specimens (of 26 tested; 4 serums, 4 CSFs) from 5 patients were confirmed by CBA to be GABAAR-IgG positive. Patient IgGs were always reactive with α1β3 GABAAR subunits. One more patient was identified clinically after this validation study. Median age for the 6 patients at serologic diagnosis was 44 years (range, 1–71 years), and 4 of them were male. Among the 4 for whom clinical information was available (2 treated by the authors), all had encephalitis and antiepileptic drug refractory seizures. Three out of 4 patients treated with a combination of immunotherapies had good outcomes. The fourth, recognized to have an autoimmune cause late in the clinical course, had severe permanent neurologic sequelae and brain atrophy.ConclusionsThough not as common as NMDA-R encephalitis, GABAAR encephalitis generally has a characteristic clinical-radiologic presentation and is treatable, making accurate laboratory diagnosis critical.
- Published
- 2019