More on NMO Pathology and Aquaphorin story

100 percent of the lesions in NMO are perivascular around the microvessels. The perivascular staining to C9neo is far greater than in multiple sclerosis. Rosettes form. The specific antigen is aqp4 which is a membrane protein involved in water transport in NMO. AQP4 co-localizes with the NMO IgG precipitate . Staining is in pial, not endothelial and was described by Lennon and Weinshenker. AQP4 is not localized elsewhere in CNS but has been localized in crypts in gastric mucosa and distal renal tubules.