Therapeutic Plasma Exchange (TPE) in Neuromyelitis Optica Spectrum Disorders (NMOSD) and related disorders in Resource Limited Settings: Outcomes in a Multi‐ethnic Single Center Population

: We evaluated therapeutic plasma exchange (TPE) efficiency in treatment of a single relapse in steroid-refractory patients with neuromyelitis optica spectrum disorders (NMOSD) in a multi-ethnic resource-limited setting. This was a historical cohort study on the clinical outcomes post-TPE in a multiethnic cohort of 53 steroid-refractory NMOSD patients at a single Malaysian tertiary center. Primary outcomes, assessed both pre- and post-TPE, were Medical Research Council scale of muscle power, Modified Rankin Scale, Expanded Disability Status Scale (EDSS), and visual acuity. Secondary outcomes were ambulatory status and target neurological deficit (TND)-based TPE response. Significant improvements in Medical Research Council, Modified Rankin Scale, EDSS, and visual acuity (P 14 days (P = 0.047) were significantly associated with improved EDSSΔ6. TND-based TPE response was significant in absence of cord atrophy (P = 0.030). TPE is an effective treatment for steroid-refractory acute relapses of NMOSD in a multiethnic Malaysian population despite its resource-limited setting. The predictive factors of EDSSΔ6 improvement were anti-aquaporin 4 seronegativity, longer cord lesions, and higher pre-TPE EDSS. Absence of cord atrophy was predictive of better TND-based TPE response. Unexpectedly, our study showed that delayed TPE initiation of more than 14 days and up to 60 days may also be beneficial.