10-20% of patients with ALS have anti-NRIP autoantibody and the titer of anti-NRIP autoantibody is correlated with motor functional decline and mortality in ALS. The PALADIN2 clinical trial is a single arm study, which intends to enroll 20 ALS patients having anti-NRIP autoantibody in plasma. Patients will receive 3 courses of plasmapheresis per 3 months in order to maintain low concentration of anti-NRIP autoantibody in plasma. The study will follow up these patients for another 6 months after plasmapheresis. This project will potentially confirm the efficacy and safety of plasmapheresis for ALS patients having anti-NRIP autoantibody.