Clinical and laboratory features of neuromyelitis optica with oligoclonal IgG bands.

Of 23 neuromyelitis optica (NMO) cases, we found two cases with oligoclonal IgG bands (OBs). Both patients were positive for NMO-IgG. Their common features were long disease duration and co-existing autoimmune diseases (myasthenia gravis and sicca syndrome). Although OBs are mostly negative in NMO, which distinguishes it from multiple sclerosis (MS), they can be positive by long-standing autoimmunity, which may not be directly related to NMO.