Treatment of neuromyelitis optica: current debate.

Neuromyelitis optica (NMO) is an inflammatory demyelinating disease that largely affects optic nerves and spinal cord. Recent studies have identified an elevation of serum anti-aquaporin 4 antibody as a hallmark of NMO. Typical cases of NMO significantly differ from multiple sclerosis (MS) in immunological markers, histopathology, and responses to therapy. In fact, plasma exchange may be more efficacious for NMO than MS, whereas interferon-ß is recommended for MS but not for NMO. An emerging idea that pathogenesis of NMO may involve an interaction of the newly identified helper T cell subset, Th17, with B cells offers potential targets of therapy.