title: Hypercomplementemia at relapse in patients with anti-aquaporin-4 antibody.
abstract: OBJECTIVE
  Because Asian patients with opticospinal multiple sclerosis (OSMS) frequently have anti-aquaporin-4 (AQP4) antibody, complement-mediated disruption of astrocyte foot processes is proposed but not yet proven. We aimed to clarify whether complement consumption occurs at relapse in anti-AQP4 antibody-positive patients.
  
  
  METHODS
  We analyzed serum CH50, C3, C4, and C-reactive protein (CRP) levels and their relation to clinical phases in 118 MS patients with or without anti-AQP4 antibody. Serum CH50 levels were higher in 24 patients with anti-AQP4 antibody than in 39 OSMS and 54 conventional form of MS (CMS) patients without anti-AQP4 antibody at relapse (Pcorr<0.05) but not in remission. The frequency of hypercomplementemia at relapse was also higher in anti-AQP4 antibody-positive patients than in anti-AQP4 antibody-negative CMS patients (70.4% vs 29.0%, Pcorr<0.05). C3 and C4 levels did not differ significantly among the three groups at relapse. In patients with anti-AQP4 antibody, the coexistence of hypercomplementemia and high CRP values was more common at relapse than in the remission phase (36.0% vs 10.5%, P<0.05). In patients with extensive central nervous system lesions, hypercomplementemia was significantly more common in anti-AQP4 antibody-positive patients than anti-AQP4 antibody-negative ones (88.9% vs 16.7%, P<0.01). We consider that hypercomplementemia in anti-AQP4 antibody-positive patients may reflect a systemic inflammatory reaction at relapse.
authors.affiliation: Department of Neurology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Doi
authors.forename: T
authors.initials: T
authors.lastname: Matsushita
authors.forename: N
authors.initials: N
authors.lastname: Isobe
authors.forename: T
authors.initials: T
authors.lastname: Matsuoka
authors.forename: M
authors.initials: M
authors.lastname: Minohara
authors.forename: H
authors.initials: H
authors.lastname: Ochi
authors.forename: J I
authors.initials: JI
authors.lastname: Kira
mesh_terms: D000328:Adult; D051401:Aquaporin 4 / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood*; D002097:C-Reactive Protein / Q000276:immunology / Q000378:metabolism; D003176:Complement C3 / Q000276:immunology / Q000378:metabolism*; D003181:Complement C4 / Q000276:immunology / Q000378:metabolism*; D015941:Complement Hemolytic Activity Assay; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000276:immunology* / Q000473:pathology; D009471:Neuromyelitis Optica / Q000276:immunology* / Q000473:pathology
chemical_list: C496030:AQP4 protein, human; D051401:Aquaporin 4; D001323:Autoantibodies; D003176:Complement C3; D003181:Complement C4; D002097:C-Reactive Protein