Author Affiliations: Department of Clinical Neurology, John Radcliffe Hospital, Oxford, England.
We read with interest the case series by Kim and colleagues1 on the use of mitoxantrone in patients with highly relapsing neuromyelitis optica (NMO).
This study demonstrates a promising reduction in relapse rates following treatment with mitoxantrone. We note, however, that all but 1 patient were treated with interferon beta before the introduction of mitoxantrone. Recently, it has been shown that interferon beta may exacerbate NMO and precipitate relapses.2 Use of this agent may have contributed to the high premitoxantrone relapse rates, thus confounding the apparent beneficial effects of mitoxantrone.
Kitley JL, Leite MI, Matthews LAE, Palace J. Use of Mitoxantrone in Neuromyelitis Optica. Arch Neurol. 2011;68(8):1086-1087. doi:10.1001/archneurol.2011.170