CAR-T in Subjects With Relapsed/Refractory Autoimmune Disease

"This is a prospective, single-center, open, single-arm, dose-escalation clinical trial to evaluate the safety and efficacy of CAR-T cell therapy in patients with relapsed/refractory autoimmune diseases. Intravenous infusion will be used, and the trial procedure will be divided as follows:~1. Screening period (D-28 to D-6):~ After subjects voluntarily sign an informed consent form, a screening period will be conducted to determine whether subjects are eligible for the trial based on inclusion and exclusion criteria.~2. Lymphocyte depletion pretreatment (Study D-5 to Study D-3):~ Subjects will be pre-treated with Lymphocyte depletion starting 5 days prior to CAR-T cell infusion (FC regimen)~3. Rest and Observation (Study D-2 to Study D-1):~ Follow the study procedures and perform the relevant examinations during the rest and observation period.~4. Cell Infusion and Primary Study Endpoint Observation Period (Study D0 to W12 post-infusion):Subjects will undergo CAR-T cell infusion at 2-da"