However, the discovery of pathogenic antibodies to aquaporin-4 at the beginning of the 21st century revived interest in the syndrome, and AQP4-IgG-positive NMO spectrum disorders (NMOSD) are now studied as prototypical autoimmune diseases.
This association persisted after stratification analysis for aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) positivity (OR = 1.397, 95% CI 1.021-1.912; P = 0.036) and stratification according to coexisting autoimmune diseases (OR = 1.446, 95% CI 1.072-1.952; P = 0.015).
Neuromyelitis optica (NMO) and neuromyelitis optica spectrum disorder (NMOSD) are autoimmune diseases associated with a disease-specific autoantibody directed against the water channel protein aquaporin-4.
Neuromyelitis optica spectrum disorder (NMOSD) is a B-cell-mediated disease with autoimmunity towards the astrocyte water channel aquaporin-4 (AQP-4) in the central nervous system.
Interest in AQP4 has increased since it was discovered to be the target antigen in the inflammatory autoimmune disease neuromyelitis optica spectrum disorder (NMOSD).
Neuromyelitis optica (NMO) is an autoimmune disease associated with NMO immunoglobulin G (NMO-IgG), an antibody that selectively binds to the aquaporin-4.
Neuromyelitis optica (NMO) and myasthenia gravis (MG) are autoimmune diseases mediated by autoantibodies against either aquaporin 4 (AQP4) or acetylcholine receptor (AChR), respectively.
The majority of NMOSD patients have autoimmunity against aquaporin-4 (AQP4), evidenced by seropositivity for autoantibodies against aquaporin-4 (AQP4-IgG).
Our observations support that AQP4-IgG positive NMOSDs patients have underlying AQP4 autoimmunity and suggest that ON (symptomatic or asymptomatic) may trigger formation of orbital ectopic GC contributing to development of high-affinity AQP4-specific memory B cells and plasma cells, which produce highly pathogenic AQP4-IgG.
Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disease associated with a serological antibody to aquaporin-4 (AQP4) detectable in up to 80% of patients.
While it is recognized that aquaporin-4 (AQP4)-specific T cells and antibodies participate in the pathogenesis of neuromyelitis optica (NMO), a human central nervous system (CNS) autoimmune demyelinating disease, creation of an AQP4-targeted model with both clinical and histologic manifestations of CNS autoimmunity has proven challenging.
The target antigen of autoimmunity in NMO is the water channel aquaporin-4 (AQP4), and antibodies directed against this antigen result in astrocyte damage.
The discovery of aquaporin-4 antibodies (NMO-IgG) has revived the interest in NMO, which is now extensively studied as a prototypic autoimmune condition.
Multivariate analysis showed that negative anti-aquaporin-4 IgG, concomitance with autoimmune diseases/antibodies, and no treatment in remission were risk factors of recurrence.
The discovery of a highly specific antibody against the aquaporin-4 (AQP4) water channel (AQP4-IgG) unified the spectrum of neuromyelitis optica spectrum disorders (NMOSD), which are considered to be antibody-mediated autoimmune diseases.
Reports of neuromyelitis optica spectrum disorder (NMOSD) occurring in the setting of neoplasia suggest that aquaporin-4autoimmunity may in some cases have a paraneoplastic basis.