title: Does interferon beta treatment exacerbate neuromyelitis optica spectrum disorder?
abstract: OBJECTIVE
  Recent case reports and series have shown that patients with neuromyelitis optica (NMO) experience clinical deterioration under interferon beta (IFN-β) treatment. The objective of the present study was to evaluate whether and to what extent IFN-β exacerbates NMO spectrum disorders (NMOSD).
  
  
  METHODS
  We retrospectively reviewed the medical records of 40 patients with NMOSD who had been treated with IFN-β for more than 6 months and whose disease duration was more than 1 year at the initiation of IFN-β treatment. We evaluated their annualized relapse rates (ARR) and Expanded Disability Status Scale (EDSS) scores before and after IFN-β treatment.
  
  
  RESULTS
  In total, 95% of patients exhibited an ineffective or exacerbated response to IFN-β treatment and the mean ARR significantly increased after IFN-β treatment (p = 0.002). The increased ARR > 50% under IFN-β treatment was observed in 20 patients (50%). The mean EDSS score significantly increased following IFN-β treatment (p < 0.001).
  
  
  CONCLUSIONS
  In patients with NMOSD, IFN-β treatment is not only ineffective for preventing relapses but also may even increase relapses significantly. Thus, a more careful diagnostic approach to differentiate NMO from multiple sclerosis and attention to decision of treatment is warranted for patients at high risk of NMO.
authors.affiliation: Department of Neurology, Research Institute and Hospital of National Cancer Center, 323 Ilsan street, Ilsandong-gu, Goyang-si, Gyeonggi-do, Korea.
authors.forename: Su-Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Woojun
authors.initials: W
authors.lastname: Kim
authors.forename: Xue Feng
authors.initials: XF
authors.lastname: Li
authors.forename: In-Ja
authors.initials: IJ
authors.lastname: Jung
authors.forename: Ho Jin
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006801:Humans; D007155:Immunologic Factors / Q000009:adverse effects*; D016899:Interferon-beta / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D009471:Neuromyelitis Optica / Q000188:drug therapy* / Q000473:pathology*; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D007155:Immunologic Factors; D016899:Interferon-beta