NMO-IgG: Differentiating Neuromyelitis Optica from Multiple Sclerosis

New findings confirm the strong association of NMO-IgG, a serum autoantibody that targets aquaporin-4, with longitudinally extensive spinal cord lesions and Asian optic-spinal multiple sclerosis/neuromyelitis optica.

Neuromyelitis optica (NMO), an idiopathic CNS demyelinating disease, is characterized by severe attacks of optic neuritis and myelitis. NMO pathology differs from that of classic multiple sclerosis (MS). NMO is associated with NMO-IgG, a highly specific serum autoantibody marker that targets the water channel aquaporin-4 (AQP4). NMO-IgG is detected in about 70% to 75% of patients with NMO and in >50% of patients with either “longitudinally extensive” transverse myelitis (LETM; presence of a spinal cord MRI lesion spanning three or more vertebral segments) or recurrent isolated optic neuritis. NMO-IgG is not detected in classic MS.

These researchers evaluated 35 MS patients in Japan — 13 with “conventional” MS, 19 with an “optic-spinal” form …

Reviewing Author

Dean M. Wingerchuk, MD, MSc, FRCP(C)