[Antibody-related neuroimmunological disorders: update on the diagnosis and treatment].

Varieties of autoantibodies are known to relate to autoimmune neurological disorders as the diagnostic and therapeutic markers. Some of them affected directly to the pathomechanisms of neurological diseases. Recently several autoantibodies with such roles have been reported showing the common characters as recognizing cell surface antigens. Among them, anti-aquaporin 4 antibody (AQP4-Ab) in neuromyelitis optica (NMO) and anti-NMDA receptor antibody (NMDAR-Ab) in non-herpetic limbic encephalitis are drawn considerable attention. The features of NMO with AQP4-Ab are as higher age at onset, extreme women preponderance, severe optic neuritis and myelitis with longitudinary extended spinal cord lesions. AQP4-Ab binds to the astrocytic endfeet extended toward cerebrospinal fluid space or vessel wall, related to the common lesions of NMO, and passive transfer of the antibody with complements to rodents showed NMO pathology. The NMDAR-Ab related encephalitis is seen in young women having ovary teratoma showing memory and consciousness disturbances, agitation, epilepsy, respiratory failure, autonomic disorders and involuntary movements. We showed this antibody really affects to NMDAR specific signal transduction using rodent hippocampal slices with suppression of long-term potentiation induction. The discovery of newly characterized autoantibodies with relation to certain neurological diseases will be expected to expand in the future.