RecruitingDrug trialA Clinical Study of the Safety, Tolerability and Preliminary Efficacy of CD19/BCMA-targeted CAR-T Therapy in Refractory Autoimmune DiseasesThis study is an investigator-initiated single center, single arm clinical study with a target population of patients with refractory autoimmune diseases. It is an early exploratory clinical study of the safety, tolerability and initial efficacy of CD19/BCMA CAR-T in the treatment of refractory autoimmune diseases.