Other Autoimmune Diseases (AID)

This is a single-center, open-label, non-randomized, single-arm clinical trial. Patients with refractory lupus neritis (SLE-LN), systemic sclerosis (SSc), primary Sjogren syndrome combined with pulmonary artery hypertension (pSS-PAH) and other autoimmune diseases (AID) receive CD19-BCMA CAR T cell therapy. Phase I (Dose-Escalation/Dose-De-escalation Phase)：The primary objective is to prospectively assess the safety of CD19-BCMA CAR T cell therapy in patients with SLE-LN, SSc, pSS-PAH and other autoimmune diseases (AID).Phase I (Dose-Escalation/Dose-De-escalation Phase)：Primary Endpoint: Safety, tolerability, and determination of the optimal biological dose (OBD) and the Phase II recommended dose (RP2D) in patients with SLE-LN, SSc, pSS-PAH, and other autoimmune diseases (AID).Phase II (Dose-Expansion Phase):Overall remission rate (ORR) \[Time Frame: 90,180 Days\]