This is an uncontrolled, prospective, observational cohort study in patients with RMS or NMOSD who will receive ofatumumab treatment over an observational period of 12 month. Ofatumumab was administrated 20mg by subcutaneous injection on Days 1, 7 and 14 for initial loading, followed by monthly infusion up to 12 months. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) will be performed to assess meningeal lymphatic flow in participants before and after ofatumumab treatment.The change of immune cell landscape in RMS or NMOSD patients after receiving ofatumumab treatment will be monitored by mass cytometry (CyTOF). Assessments also include clinical assessments( clinical relapse rate and EDSS score) and MRI assessments (T2 lesion load, T1 gadolinium enhancing lesion number).
