Plasma Exchange in Severe Attacks of Neuromyelitis Optica Mickael Bonnan 1 and Philippe Cabre 2 1 Service de Neurologie, Hopital F.
Fazio R et al. – Neuromyelitis optica (NMO) is a rare demyelinating disease, affecting selectively the optic nerve and the spinal cord. It was previously considered to be a severe variant of multiple sclerosis (MS) due to the similar pathological features and its resemblance to optico–spinal, or Japanese, MS, typical of Asian populations.
Devic’s syndrome was first described in 1870 by Sir Thomas Allbutt (what a name to have had as a kid!) who pointed out an association between myelitis and optic nerve disorder.? In 1894, Eugene Devic and his student Fernand Gault described 16 patients who had lost vision in one or both eyes and developed spastic weakness, sensory loss, and incontinence.? The other name of the condition was neuromyelitis optica (NMO). A major breakthrough came in 2004 when a specific marker NMO-IgG was found for the disorder [1].? IgG stands for immunoglobulin (a kind of antibody).
The astrocytic aquaporin-4 (AQP4) water channel is the target of pathogenic antibodies in a spectrum of relapsing autoimmune inflammatory central nervous system disorders of varying severity that is unified by detection of the serum biomarker neuromyelitis optica (NMO)-IgG. Neuromyelitis optica is the most severe of these disorders. The two major AQP4 isoforms, M1 and M23, have identical extracellular residues.
Aquaporin-4 (AQP4) deficiency in mice reduces neuroinflammation in experimental autoimmune encephalomyelitis (EAE) produced by active immunization with myelin oligodendrocyte glycoprotein peptide (MOG).
Neuromyelitis optica (NMO) is an inflammatory autoimmune demyelinating disease of the central nervous system (CNS) which in autoantibodies produced by patients with NMO (NMO-IgG) recognize a glial water channel protein, Aquaporin-4 (AQP4) expressed as two major isoforms, M1- and M23-AQP4, in which the plasma membrane form orthogonal arrays of particles (OAPs). AQP4-M23 is the OAP-forming isoform, whereas AQP4-M1 alone is unable to form OAPs.