Maintenance plasma exchange therapy for steroid-refractory neuromyelitis optica

Neuromyelitis optica (NMO) is a severe inflammatory demyelinating disease of the central nervous system with exacerbations involving the optic nerves, spinal cord, or both. This study explores the utility of maintenance plasma exchange (mTPE) as a therapy in patients with relapsing, corticosteroid-refractory, NMO. This retrospective case series presents data on patients who were diagnosed with NMO using currently accepted criteria. These patients were refractory to high-dose corticosteroids and received mTPE. Seven patients met the criteria for NMO diagnosis and all were positive for antibodies against aquaporin-4. Over a mean of 7.1 years (range, 2-16), these patients received between 21 and 154 TPE treatments (mean, 76). Although treated with mTPE, five out of the seven patients improved by more than one point on the Expanded Disability Status Scale. Interruption in mTPE in five patients resulted in clinical worsening. When mTPE was restarted in three out of the five patients who experienced a cessation of mTPE, these patients either stabilized or improved. The two patients who did not restart the mTPE protocol died. Patients treated with mTPE also experienced a reduction in the number of NMO exacerbations. Finally, stabilization of the retinal nerve fiber layer thickness was observed while on mTPE. In this preliminary study, mTPE appeared safe and may bring about improvement in disability and sustained stabilization of the clinical course in patients with steroid-refractory relapsing forms of NMO.