This study is a phase Ib/IIa dose-escalation study designed to evaluate the safety, tolerability, and preliminary efficacy of autologous T cells expressing chimeric antigen receptor (CAR)-targeted B-cell activating factor receptor (BAFFR) in refractory neuroimmune diseases. The study design is divided into two parts, the first of which will be given to each patient at 3 incremental dose levels to establish the maximum tolerated dose (MTD). Each disease is expected to enroll 12 patients who meet the inclusion criteria. In the second part, 15 patients per disease will be recruited to further characterize the efficacy of the MTD.