AQP4 and neuromyelitis optica: A total of 51 AQP4-ab-positive patients (mean age, 43.8±12.2 years; female:male = 44∶7) were included in this study and met the diagnostic criteria for NMO (n = 26)[16] or the suggestion of NMOSD (n = 25) (Table 1).[17] The mean interval from onset to sampling (disease duration) in patients was 5.3±6.1 years (range, 0.01–32.44), EDSS score was 3.8±2.3 (range, 1–9.5) and ARR was 0.8±0.8 (0.0–3.4).