Author Affiliations: Department of Neurology, Research Institute and Hospital of National Cancer Center, Gyeonggi-do, South Korea.
We thank Kitley and colleagues for their interest in our article and their comments. All patients described in our article1 were referred to our center from other hospitals owing to frequent relapses despite treatment. In fact, many of them were treated with interferon beta after a diagnosis of optic-spinal multiple sclerosis. As Kitley and colleagues pointed out, based on the recent studies,2,3 treatment with interferon beta might have contributed to the high pretreatment relapse rate, which could have made mitoxantrone treatment appear more efficacious in our study. However, what we want to emphasize is that 6 cycles of mitoxantrone induction treatment effectively suppressed the highly active disease status, even if it might result from inappropriate treatment.
Kim S, Kim HJ. Use of Mitoxantrone in Neuromyelitis Optica—Reply. Arch Neurol. 2011;68(8):1086-1087. doi:10.1001/archneurol.2011.171