title: Failure of natalizumab to prevent relapses in neuromyelitis optica.
abstract: OBJECTIVE
  To describe first experiences with the integrin inhibitor natalizumab, given to patients with suspected relapsing-remitting multiple sclerosis (MS) who were later diagnosed with aquaporin 4-positive neuromyelitis optica (NMO).
  
  
  METHODS
  Retrospective case series.
  
  
  METHODS
  Neurology departments at tertiary referral centers in Germany.
  
  
  METHODS
  Patients with NMO who tested positive for antibodies to aquaporin 4.
  
  
  METHODS
  Treatment with natalizumab.
  
  
  METHODS
  Relapses and accumulation of disability.
  
  
  RESULTS
  We identified 5 patients (4 female; median age, 45 years) who were initially diagnosed with MS and treated with natalizumab before diagnosis of NMO was established. Natalizumab was given as escalation therapy after failure of first- or second-line immunomodulatory therapies for MS. During natalizumab therapy (median duration, 8 infusions; range, 2-11 infusions), all 5 patients displayed persisting disease activity; a total of 9 relapses occurred (median duration to relapse, 120 days; range, 45-230 days) after the start of treatment. Four patients had an accumulation of disability and 1 patient died 2 months after cessation of natalizumab treatment.
  
  
  CONCLUSIONS
  Our results suggest that natalizumab fails to control disease activity in patients with NMO. Neuromyelitis optica should be considered as a differential diagnosis in patients with suspected MS who are unresponsive to natalizumab therapy.
authors.affiliation: Department of Neurology, University Medical Center Regensburg, Regensburg, Germany. ingo.kleiter@rub.de
authors.forename: Ingo
authors.initials: I
authors.lastname: Kleiter
authors.forename: Kerstin
authors.initials: K
authors.lastname: Hellwig
authors.forename: Achim
authors.initials: A
authors.lastname: Berthele
authors.forename: Tania
authors.initials: T
authors.lastname: Kümpfel
authors.forename: Ralf A
authors.initials: RA
authors.lastname: Linker
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Hartung
authors.forename: Friedemann
authors.initials: F
authors.lastname: Paul
authors.forename: Orhan
authors.initials: O
authors.lastname: Aktas
mesh_terms: D000328:Adult; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D051401:Aquaporin 4 / Q000097:blood / Q000276:immunology; D001323:Autoantibodies / Q000032:analysis; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000150:complications / Q000188:drug therapy; D000069442:Natalizumab; D009471:Neuromyelitis Optica / Q000517:prevention & control*; D055502:Secondary Prevention; D017211:Treatment Failure; D016896:Treatment Outcome
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D051401:Aquaporin 4; D001323:Autoantibodies; D000069442:Natalizumab