Abstract: Neuromyelitis optica (NMO) is a rare demyelinating disease, affecting selectively optic nerve and spinal cord. NMO-IgG, an auto-antibody against aquaporin-4 (AQP4), identifies NMO as a disease entity separating from a severe variant of multiple sclerosis (MS). AQP4 is particularly abundant on the central nervous system, and is involves in regulation of water among of glial cells, and the blood and cerebrospinal fluid. NMO-IgG can target the AQP4 and initiate immune response leading to AQP4 protein loss in lesions, which is the key pathological mechanism of NMO.

Key words: neuromyelitis optica, aquaporin-4, neuromyelitis optica-IgG, review