Different responses to interferon beta-1b treatment in patients with neuromyelitis optica and multiple sclerosis.
BACKGROUND
Although the benefit of treatment for relapsing-remitting multiple sclerosis (MS) is firmly established, whether interferon beta-1b (IFNB-1b) therapy is efficacious for neuromyelitis optica (NMO) has been debated.


METHODS
We reviewed the responses to IFNB-1b treatment in 18 patients with relapsing NMO and compared the results with those from 38 patients with relapsing-remitting MS. We compared clinical characteristics, the annualized relapse rate (ARR) and the probability of being relapse free before and after IFNB-1b treatment in patients with NMO and MS.


RESULTS
The proportion of patients with more than 50% increase in the ARR after IFNB-1b treatment was much higher in NMO than in MS (P = 0.046). ARR was significantly lower in patients with MS after IFNB-1b administration than before (P = 0.015), but not in NMO. Kaplan-Meier and log-rank statistical analyses revealed that relapse-free rates were lower in NMO than MS after IFNB-1b treatment (P = 0.032). The analyses also showed lower relapse-free rates during the pre-IFNB-1b treatment period than the post-IFNB-1b treatment period in MS (P < 0.001), but not in NMO.


CONCLUSIONS
IFNB-1b treatment does not appear to be effective for preventing relapse in NMO likely because of differences between the immune-pathogenesis of NMO and MS.
Uzawa
A
A
Department of Neurology, Graduate School of Medicine, Chiba University, Chiba, Japan. a-uzimp1204@graduate.chiba-u.jp
Mori
M
M
Hayakawa
S
S
Masuda
S
S
Kuwabara
S
S
D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000009:adverse effects; D000328:Adult; D005260:Female; D006801:Humans; D007111:Immunity, Cellular; D000068576:Interferon beta-1b; D016899:Interferon-beta / Q000008:administration & dosage* / Q000009:adverse effects; D008214:Lymphocytes / Q000276:immunology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000188:drug therapy* / Q000276:immunology; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000188:drug therapy / Q000276:immunology; D009471:Neuromyelitis Optica / Q000188:drug therapy* / Q000276:immunology; D017063:Outcome Assessment, Health Care / Q000379:methods; D012008:Recurrence; D012189:Retrospective Studies; D017211:Treatment Failure; D016896:Treatment Outcome
D000276:Adjuvants, Immunologic; D000068576:Interferon beta-1b; D016899:Interferon-beta