title: Neuromyelitis optica relapses: Race and rate, immunosuppression and impairment.
abstract: OBJECTIVE
  Neuromyelitis optica (NMO) is a rare antibody-mediated CNS disease characterised by disabling relapses leading to high morbidity and mortality. Understanding relapse activity and severity is important for treatment decisions and clinical trial design. We assessed (1) whether clinical and demographic factors associate with different relapse rates and (2) the relative impact of immunosuppressive treatments on relapse rates and on attack-related residual disability.
  
  
  METHODS
  Clinical, demographic and treatment data were prospectively collected from 79 consecutive aquaporin 4 antibody positive patients seen in the nationally commissioned Oxford NMO service. The influence of clinical features on annualised relapse rates (using multiple regression) and the effect of immunosuppression on relapse-associated residual disability for transverse myelitis and optic neuritis attacks (using a mixed effect model) were analysed.
  
  
  RESULTS
  The mean annualised relapse rate was 0.93. Relapse rates were significantly higher in Afro-Caribbeans, children and in those of shorter disease duration. Relapse rates reduced on treatment (from 0.87 to 0.42). Delay to first treatment did not influence eventual on-treatment relapse rate. Immunosuppressive treatment significantly reduced the residual disability from ON (p<0.01), and TM (p=0.029) attacks.
  
  
  CONCLUSIONS
  Relapse rates in NMO are influenced by multiple factors, including age, ethnicity and disease duration. Current immunosuppressive treatments reduce but do not abolish relapses, however, they appear to additionally lessen the chronic disabling effect of a relapse.
authors.affiliation: Nuffield Department of Clinical Neurosciences, Oxford University, John Radcliffe Hospital, Oxford, UK.
authors.forename: George
authors.initials: G
authors.lastname: Tackley
authors.affiliation: Alexion Pharmaceutical, 55 Cambridge Parkway (Suite 800), Cambridge, MA 02142, USA.
authors.forename: Fanny
authors.initials: F
authors.lastname: O'Brien
authors.affiliation: Nuffield Department of Clinical Neurosciences, Oxford University, John Radcliffe Hospital, Oxford, UK.
authors.forename: João
authors.initials: J
authors.lastname: Rocha
authors.affiliation: Nuffield Department of Clinical Neurosciences, Oxford University, John Radcliffe Hospital, Oxford, UK.
authors.forename: Mark
authors.initials: M
authors.lastname: Woodhall
authors.affiliation: Nuffield Department of Clinical Neurosciences, Oxford University, John Radcliffe Hospital, Oxford, UK.
authors.forename: Patrick
authors.initials: P
authors.lastname: Waters
authors.affiliation: Department of Paediatric Neurology, John Radcliffe Hospital, Oxford, UK.
authors.forename: Saleel
authors.initials: S
authors.lastname: Chandratre
authors.affiliation: Department of Neurology, Southampton General Hospital, Southampton, UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Halfpenny
authors.affiliation: Department of Neurology, Great Ormond Street Hospital, London, UK.
authors.forename: Cheryl
authors.initials: C
authors.lastname: Hemingway
authors.affiliation: Department of Neurology, Birmingham Children's Hospital, Birmingham, UK.
authors.forename: Evangeline
authors.initials: E
authors.lastname: Wassmer
authors.affiliation: Alexion Pharmaceutical, 55 Cambridge Parkway (Suite 800), Cambridge, MA 02142, USA.
authors.forename: Warren
authors.initials: W
authors.lastname: Wasiewski
authors.affiliation: Nuffield Department of Clinical Neurosciences, Oxford University, John Radcliffe Hospital, Oxford, UK.
authors.forename: Maria Isabel
authors.initials: MI
authors.lastname: Leite
authors.affiliation: Nuffield Department of Clinical Neurosciences, Oxford University, John Radcliffe Hospital, Oxford, UK. Electronic address: jacqueline.palace@ndcn.ox.ac.uk.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Palace
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D001379:Azathioprine / Q000627:therapeutic use; D044383:Black People; D004185:Disability Evaluation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D016018:Least-Squares Analysis; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use; D009471:Neuromyelitis Optica / Q000188:drug therapy / Q000453:epidemiology* / Q000503:physiopathology*; D011446:Prospective Studies; D012044:Regression Analysis; D000069283:Rituximab / Q000627:therapeutic use; D012621:Seasons; D012720:Severity of Illness Index
chemical_list: D007166:Immunosuppressive Agents; D000069283:Rituximab; D001379:Azathioprine; D008727:Methotrexate
keywords: Cohort study; Devic's syndrome; Immunosuppression; Neuromyelitis optica