AQP4 water channels are thought to be the target of autoimmune attack in neuromyelitis optica-spectrum disorders (NMOsd). AQP4 are highly expressed on ventricular ependyma.
Since the description of the association between neuromyelitis optica (Devic’s disease) and aquaporin 4 IgG antibody (NMO-IgG), the search for this antibody has been considered a highly recommended laboratory test when centromedullary multisegmental lesions are observed by magnetic resonance imaging (MRI). Such MRI lesions have not been confined to acute NMO because other infectious and post-infectious disorders may display a similar lesional pattern. However, NMO-IgG has not been currently searched and associated with these myelitides
Neuromyelitis optica (NMO) is an acute inflammatory disease that preferentially involves the optic nerves and spinal cord.