AQP4 and autoimmune disease: Hypertension (HR 1.58, 95%CI 0.86–2.89, P = 0.138), concomitant autoimmune disease (HR 0.43, 95%CI 0.17–1.07, P = 0.068), initial EDSS score (HR 1.11, 95%CI 0.98–1.27, P = 0.098), and folic acid level (HR 0.97, 95%CI 0.93–1.01, P = 0.193) had moderate effects, while age, gender, diabetes, anti-AQP4 antibody status, treatment methods, and serum vitamin B12 level had no correlation with relapse.