Japanese Patients With Nmo-Igg

Neuromyelitis optica (NMO) is characterized by severe optic neuritis and transverse myelitis. NMO-IgG is an autoantibody specific to NMO and optic-spinal multiple sclerosis (OSMS), and binds to the aquaporin-4 (AQP4) water channel. In contrast to classical MS, Japanese NMO-IgG-positive patients have longitudinally extensive spinal cord lesions (> 3 vertebral segments), and are often blind at least in one eye. Some of them have unique brain lesions. We recently found that loss of AQP4 in the lesions distinguishes NMO from classical MS. Efficacy of long-term corticosteroid therapy in NMO also underscores the distinct pathogenesis of NMO from classical MS.