[Treatment and clinical management of patients with neuromyelitis optica and anti-aquaporin 4 antibody].

Neuromyelitis optica (NMO) is a unique inflammatory condition characterized by selective involvement of the optic nerves and spinal cord. The cardinal features of NMO and a tendency of recurrence led to the classification of NMO as a subtype of multiple sclerosis (MS); however, it can be distinguished from MS on the basis of clinicoradiological and serological findings. In particular, NMO is characterized by the presence of spinal cord lesions that are longer than the total length of 3 vertebral segments and presence of anti-aquaporin 4 antibodies. Secondary progression of this condition is usually not observed, and therapy for NMO patients is designed to prevent acute exacerbations and limit irreversible neurological disability. Intravenous administration of a high dose of methylprednisolone is a standard treatment for patients with acute exacerbations of this condition, and patients with refractory cases are often responsive to plasmapheresis. To reduce the frequency of relapses and severity, standard therapies for MS, such as interferon-beta therapy, are not effective; further, a long-term immunosuppressive therapy is required for NMO patients. Immunosuppressive therapies often involve oral administration of prednisolone with or without azathioprine; patients who are refractory to the oral therapy may be treated by parental administration of cyclophosphamide, mitoxantrone, or rituximab. At present, there is no cure for NMO; early and precise diagnosis is critical to initiate immunosuppressive therapy for prevention of relapse.