Neuromyelitis optica: potential roles for intravenous immunoglobulin.

Neuromyelitis optica (NMO) is an idiopathic central nervous system inflammatory demyelinating disease that causes optic neuritis, transverse myelitis, and other CNS syndromes. It is distinct from multiple sclerosis and is associated with autoantibodies that target aquaporin-4 (AQP4), an astrocyte water channel. Evidence indicating antibody-mediated immune injury in NMO includes its association with other autoimmune diseases, lesional pathology that reveals prominent complement activation and immunoglobulin deposition, pathogenic potential of AQP4 autoantibodies based on in vitro studies, and reports of putative animal models of the disease. The rationale and potential role for intravenous immunoglobulin in NMO will be discussed in the context of both relapse treatment and relapse prevention.