Figure 1. Integrative model of NMO/SD pathogenesis.

Distinct stages of disease are illustrated as relative temporal and spatial comparators in NMO/SD progression. Note that over the course of disease progression and demyelination, additional autoantigens may be revealed and/or recognized, potentially resulting in antigen spreading and expansion/compounding of autoreactivity. A = astrocyte (AQP4-expressing cells that support neuronal viability and function); AQP4 = aquaporin 4; B = B lymphocyte; BBB = blood-brain barrier; E = eosinophil; M = monocyte/macrophage; N = neuron; NK = natural killer cell; NMO/SD = neuromyelitis optica/spectrum disorder; P = polymorphonuclear leukocyte (neutrophil); PER = periphery; T = T lymphocyte.