title: Neuromyelitis optica spectrum disorders: comparison of clinical and magnetic resonance imaging characteristics of AQP4-IgG versus MOG-IgG seropositive cases in the Netherlands.
abstract: OBJECTIVE
  Neuromyelitis optica spectrum disorders (NMOSDs) are a group of rare inflammatory demyelinating disorders of the central nervous system. The identification of specific antibodies directed to aquaporin 4 (AQP4-IgG) led to the distinction from multiple sclerosis. However, up to 25% of the clinically diagnosed NMO patients are seronegative for AQP4-IgG. A subgroup of these patients might be identified by antibodies directed to myelin oligodendrocyte glycoprotein (MOG-IgG). Our objective was to investigate whether the clinical characteristics of these patients differ.
  
  
  METHODS
  Using a cell-based assay, samples of 61 AQP4-IgG seronegative patients and 41 AQP4-IgG seropositive patients with clinically NMOSD were analysed for the presence of MOG-IgG. Clinical characteristics of the AQP4-IgG, MOG-IgG seropositive and double seronegative NMOSD patients were compared.
  
  
  RESULTS
  Twenty of the 61 AQP4-IgG seronegative patients tested MOG-IgG seropositive (33%). MOG-IgG seropositive patients were more frequently males in contrast to AQP4-IgG seropositive patients (55% vs. 15%, P < 0.01) and Caucasians (90% vs. 63%, P = 0.03). They more frequently presented with coincident optic neuritis and transverse myelitis (40% vs. 12%, P = 0.02) and had a monophasic disease course (70% vs. 29%, P < 0.01). AQP4-IgG seropositive patients were 2.4 times more likely to suffer from relapses compared with MOG-IgG seropositive patients (relative risk 2.4, 95% confidence interval 1.2-4.7). AQP4-IgG seropositive patients had higher Expanded Disability Status Scale levels at last follow-up (P < 0.01).
  
  
  CONCLUSIONS
  Antibodies directed to MOG identify a subgroup of AQP4-IgG seronegative NMO patients with generally a favourable monophasic disease course.
authors.affiliation: Department of Neurology, MS Centre ErasMS, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: E D
authors.initials: ED
authors.lastname: van Pelt
authors.affiliation: Department of Neurology, MS Centre ErasMS, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Y Y M
authors.initials: YY
authors.lastname: Wong
authors.affiliation: Department of Neurology, MS Centre ErasMS, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: I A
authors.initials: IA
authors.lastname: Ketelslegers
authors.affiliation: Department of Immunopathology and Blood Coagulation, Sanquin Diagnostic Services, Amsterdam, The Netherlands.
authors.forename: D
authors.initials: D
authors.lastname: Hamann
authors.affiliation: Department of Neurology, MS Centre ErasMS, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: R Q
authors.initials: RQ
authors.lastname: Hintzen
mesh_terms: D000328:Adult; D051401:Aquaporin 4 / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D063308:Myelin-Oligodendrocyte Glycoprotein / Q000276:immunology*; D009188:Myelitis, Transverse / Q000097:blood / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology; D009426:Netherlands / Q000453:epidemiology; D009471:Neuromyelitis Optica / Q000097:blood / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology; D009902:Optic Neuritis / Q000097:blood / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology
chemical_list: C496030:AQP4 protein, human; D051401:Aquaporin 4; D001323:Autoantibodies; D007074:Immunoglobulin G; C571326:MOG protein, human; D063308:Myelin-Oligodendrocyte Glycoprotein
keywords: AQP4-IgG; MOG-IgG; NMO spectrum disorders; neuromyelitis optica