Objective To analyse autoantibody status in a well-defined European multicentre cohort of patients with epilepsy of unknown aetiology and to validate the recently proposed Antibody Prevalence in Epilepsy (APE2) and Response to ImmunoTherapy in Epilepsy (RITE2) scores.
Methods We retrospectively collected clinical and paraclinical data of 92 patients referred to the Neurology Units of Verona and Salzburg between January 2014 and July 2019 with new-onset epilepsy, status epilepticus or chronic epilepsy of unknown aetiology. Fixed and live cell-based assays, tissue-based assays, immunoblot, and live rat hippocampal cell cultures were performed in paired serum/cerebrospinal fluid (CSF) to detect antineuronal and antiglial antibodies. The APE2 and RITE2 scores were then calculated and compared with clinical and laboratory data.
Results Autoantibodies were detected in 29/92 patients (31.5%), with multiple positivity observed in 6/29 cases. The APE2 score (median 5, range 1–15) significantly correlated with antibody positivity (p=0.014), especially for the presence of neuropsychiatric symptoms (p<0.01), movement disorders (p<0.01), dysautonomia (p=0.03), faciobrachial dyskinesias (p=0.03) and cancer history (p<0.01). Status epilepticus was significantly more frequent in antibody-negative patients (p<0.01). Among the items of the RITE2 score, early initiation of immunotherapy correlated with a good treatment response (p=0.001), whereas a cancer history was significantly more common among non-responders (p<0.01). Persistence of neuropsychiatric symptoms and seizures correlated with antiepileptic maintenance after at least 1 year.
Conclusions This is the first study that independently validates the APE2 and RITE2 scores and includes the largest cohort of patients whose paired serum and CSF samples have been tested for autoantibodies possibly associated with autoimmune epilepsy.
- autoimmune encephalitis
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RH and SM are joint senior authors.
RH and SM contributed equally.
Contributors SB: design and conceptualisation of the study, sample collection, cooperation in the analysis and interpretation of autoantibody tests, collection and interpretation of clinical data, data generation and interpretation and drafting the manuscript. RD, GC, FM, GZ, TZ, MT, GV, MC, FR, LDT, CZ and GTM: collection and interpretation of clinical data. FS: statistical analysis. SF and FR: collection and interpretation of clinical data, data generation and interpretation and revising the manuscript for intellectual content. ET and SalM: interpretation of clinical data and revising the manuscript for intellectual content. RH: design and conceptualisation of the study, coordination and validation of the analysis and interpretation of autoantibody tests, and revising the manuscript for intellectual content. SarM: design and conceptualisation of the study, collection and interpretation of clinical and laboratory data, data generation and interpretation, and revising the manuscript for intellectual content.
Funding This work was partly supported by grants from the 'Jubiläumsfonds der Österreichischen Nationalbank', project 16919.
Competing interests SB, RD, GC, FM, GZ, TZ, MT, GV, MC, FarR, LDT, CZ, GTM, FS, FrR, ET, SalM and RH: report no disclosures. SF received support for attending scientific meetings by Shire, Sanofi Genzyme and Euroimmun. SarM received support for attending scientific meetings by Merck and Euroimmun and received speaker honoraria from Biogen.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement All data relevant to the study are included in the article or uploaded as supplementary information. All data relevant to the study are included in the article.
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