Interferon-β1b Treatment in Neuromyelitis Optica

BACKGROUND: The effects of interferon-beta(1b) (IFN-beta(1b)) administration in multiple sclerosis (MS) patients have been confirmed, however, those in neuromyelitis optica (NMO) patients have not been shown. In this study, we assessed the effects of IFN-beta(1b) treatment on disease exacerbation and disability progression in MS or NMO patients. METHODS: We reviewed a series of 104 consecutive patients with relapsing-remitting MS (RRMS) (69) or NMO (35) treated with IFN-beta(1b) in the MS clinical center of a national hospital in Japan. RESULTS: The relapse number in the RRMS patients significantly decreased within 1 year after IFN-beta(1b) treatment (p < 0.00001); however, that in the NMO patients did not show a significant decrease (p = 0.5601). The decrease in annualized relapse rates in each RRMS patient after treatment was significant (p < 0.01), but that in each NMO patient was not (p > 0.05). The change in Kurtzke's Expanded Disability Status Scale score 1 year after treatment was higher in the NMO patients than in the RRMS patients (p = 0.0225). CONCLUSION: In NMO patients, IFN-beta(1b) treatment was not effective in reducing the relapse number and the disability progression.