Prognosis of Neuromyelitis Optica Spectrum Disorders: Differences Between Han Chinese and Tibetans, a retrospective cohort study

Abstract

Abstract Purpose To investigate the demographic characteristics and prognosis of Tibetan and Han Chinese patients with optic neuromyelitis Optica spectrum disorders (NMOSD). Methods From January 2015 to January 2022, 860 NMOSD patients were in our database. The demographic and clinical characteristics were described and retrospectively analyzed. In the subsequent analysis, we used 2 methods to eliminate confounding: a 1:3 propensity score matching (PSM) was performed and univariable cox regression was used to analyze the effect of ethnicity to prognosis; besides, univariable and multivariable cox regression was performed in the original cohort to explore the relationship between ethnicity and disability. The risk of relapse, severe attack, visual disability, motor disability and total disability in different races were analyzed. Results This study included 406 NMOSD patients (25 Tibetans and 381 Han), with a mean onset age of 40 ± 40 years, an 89% female population, and a median disease duration of 50 months. The most affected areas were the optic nerve (48%) and spinal cord (76%), no Tibetans developed area postrema syndromes (APS). 322 (79%) patients suffered at least 1 relapse, 156 (38%) suffered severe attack, 60 (15%) and 47 (12%) patients developed permanent visual and motor disability respectively. The total rate of disability was 23% (98 patients). Results from both methods showed a higher risk of severe attack, visual disability, and total disability in Tibetan, but the risk of relapse and motor disability did not differ between races. Conclusions our study demonstrated that compared with Han Chinese, Tibetans show a higher risk of disability.