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 Lopez Chiriboga; Sean J Pittock; Eoin P Flanagan

doi:10.1177/20552173211052656

Diagnostic value of aquaporin-4-IgG live cell based assay in neuromyelitis optica spectrum disorders

Mult Scler J Exp Transl Clin. 2021 Nov 26;7(4):20552173211052656. doi: 10.1177/20552173211052656. eCollection 2021 Oct.

Authors

Affiliations

¹ Departments of Neurology, Mayo Clinic College of Medicine, Rochester, MN, USA.
² Laboratory Medicine and Pathology, Mayo Clinic College of Medicine, Rochester, MN, USA.
³ Department of Neurology, Mayo Clinic College of Medicine, Scottsdale, AZ, USA.
⁴ Department of Neurology, Mayo Clinic College of Medicine, Jacksonville, FL, USA.

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.