Figure 1. Distribution of neuromyelitis optica (NMO)/aquaporin-4 (AQP4)-immunoglobulin G (IgG) titers by 6 assays in serum samples of patients and controls.

Scatterplots of the 6 assays with cutoffs shown as dotted lines. The ELISA-R has 2 cutoffs, the recommended cutoff (5 U/mL) and a modified cutoff (1.6 U/mL). CBA = cell-based assay; DC = disease control; FACS = fluorescence-activated cell sorting; FIPA = fluorescence immunoprecipitation assay; FU = fluorescence units; HC = healthy controls; IIF = indirect immunofluorescence; M = Mayo Clinic; ΔMGFI = difference in median green fluorescence intensity; NMOSD = neuromyelitis optica spectrum disorder; O = Oxford.