The patient was thought to have NMO and went on to have aquaporin-4 antibody assay:
Neuromyelitis Optica antibodies: POSITIVE.
Comment :
AQP4-transfected cells............POSITIVE
Rodent tissue.....................POSITIVE
NMO-IgG positive on both tissue and AQP4-transfected cells. These results are consistent with the presence of a neuromyelitis optica spectrum disorder (NMOSD). NMO-IgG has a sensitivity and specificity of 48-77% and 97-100% respectively for NMOSD (Waters et al. Neurology 2012 Feb28;78(9):665-71).