Diagnostic value of aquaporin-4-IgG live cell based assay in neuromyelitis optica spectrum disorders
Vyanka Redenbaugh, Mayra Montalvo, Elia Sechi, Marina Buciuc, James P. Fryer, Andrew McKeon, Vanda A. Lennon, John R. Mills, Brian G. Weinshenker, Dean M. Wingerchuk, John J. Chen, M. Tariq Bhatti, A. Sebastian López‐Chiriboga, Sean J Pittock, Eoin P. Flanagan
Abstract
OBJECTIVE: Determine the utility of aquaporin 4 IgG (AQP4-IgG) testing (live cell-based assay) for Neuromyelitis Optica Spectrum Disorders (NMOSD). METHODS: We included Mayo Clinic patients (1/1/2018-12/31/2019) tested for serum AQP4-IgG by live cell-based flow-cytometric assay. Medical records were reviewed to assess if patients fulfilled 2015 NMOSD criteria. RESULTS: Of 1371 patients tested, 41 were positive (3%) and all fulfilled NMOSD criteria with AQP4-IgG (specificity = 100%). Only 10/1330 testing negative met NMOSD criteria without AQP4-IgG (sensitivity = 80%) and seven of these 10 were MOG-IgG positive. CONCLUSIONS: AQP4-IgG by live cell-based assay was highly specific and without false positives in a high throughput setting.