Aquaporins, anti-aquaporin-4 autoantibodies and neuromyelitis optica

► Aquaporins are protein channels that allow the movement of water and other molecules. ► Aquaporin-4 is the target of an autoimmune response in neuromyelitis optica. ► Anti-AQP4 autoantibodies have diagnostic usefulness with reasonable sensitivity and high specificity. ► Anti-AQP4 can be measured, although there is no standard method.