title: Can anti-AQP4 antibody damage the blood-brain barrier?
abstract: BACKGROUND
  Aquaporin 4 (AQP4) is a water-channel protein predominantly expressed in astrocyte end feet that make up the blood-brain barrier (BBB). Recently, anti-AQP4 antibody has been identified as a specific biomarker of neuromyelitis optica (NMO). However, whether anti-AQP4 antibodies damage the BBB is unclear.
  
  
  METHODS
  We evaluated BBB damage in patients with NMO and multiple sclerosis by measuring albumin leakage (AL) and studied its correlation with anti-AQP4 antibody.
  
  
  RESULTS
  No obvious difference in AL was observed between patients with and without anti-AQP4 antibodies. In the multivariate analysis, anti-AQP4 antibody was not associated with BBB damage. Of the anti-AQP4-positive patients, 58.0% had normal AL values, and the degree of BBB damage was unrelated to the anti-AQP4 antibody titer. In addition, 41.9% of anti-AQP4-positive patients showed no gadolinium enhancement of the MRI.
  
  
  CONCLUSIONS
  These results indicate that the presence of anti-AQP4 antibody alone in plasma is insufficient to disrupt the BBB.
authors.affiliation: Department of Neurology and Neurological Science, Graduate School of Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Miho
authors.initials: M
authors.lastname: Akaza
authors.forename: Keiko
authors.initials: K
authors.lastname: Tanaka
authors.forename: Masami
authors.initials: M
authors.lastname: Tanaka
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Sekiguchi
authors.forename: Tamako
authors.initials: T
authors.lastname: Misawa
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Nishina
authors.forename: Izumi
authors.initials: I
authors.lastname: Kawachi
authors.forename: Masatoyo
authors.initials: M
authors.lastname: Nishizawa
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Mizusawa
authors.forename: Takanori
authors.initials: T
authors.lastname: Yokota
mesh_terms: D000328:Adult; D000418:Albumins / Q000378:metabolism; D051401:Aquaporin 4 / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood*; D001812:Blood-Brain Barrier / Q000503:physiopathology*; D001921:Brain / Q000503:physiopathology; D002199:Capillary Permeability / Q000502:physiology*; D005260:Female; D057809:HEK293 Cells; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000503:physiopathology*; D015999:Multivariate Analysis
chemical_list: C496030:AQP4 protein, human; D000418:Albumins; D051401:Aquaporin 4; D001323:Autoantibodies