Study of CD19 CAR-T Therapy for Refractory SLE

Inclusion Criteria: * Age ≥ 5 years, no gender limitation; * Diagnosed with SLE according to the 2019 EULAR/ACR classification criteria, and still in moderate to severe disease activity despite ≥ 3 months of high dose glucocorticoids(prednisone≥1mg/kg/d or other equivalent amount of other steroid), combined with hydroxychloroquine, and at least 2 Immunosuppressants or biologics (including cyclophosphamide, mycophenolate mofetil, azathioprine, methotrexate, cyclosporin, tacrolimus, sirolimus, leflunomide, telitacicept, belimumab, and rituximab) or intolerant to standard treatments; * SLEDAI-2K score ≥ 8 points; * The functions of vital organs must meet the following requirements: 1. cardiac function: left ventricular ejection fraction (LVEF) ≥ 50%, with no obvious abnormalities on electrocardiogram (ECG); 2. renal function: eGFR ≥ 30 mL/min/1.73m2; 3. hepatic function: AST and ALT ≤ 3.0×ULN, total bilirubin ≤ 2.0×ULN; 4. pulmonary function: no severe pulmonary lesions; blood oxygen saturation ≥ 92% under non-oxygen supplementation conditions. * Meet the criteria of leukapheresis or intravenous blood collection, and no contraindication for leukapheresis; * Negative pregnancy test for female subjects of childbearing age, and agree to take effective contraceptive measures until one year after infusion; * Participant or his/her guardians agree to participate in the clinical trial and sign the informed consent form indicating that he/she understands the purpose and procedure of the clinical trial and is willing to participate in the study. Exclusion Criteria: * Central nervous system (CNS) diseases: presence of CNS lupus symptoms requiring intervention within 60 days, including epilepsy, confusion, cerebrovascular events, etc; * Congenital heart disease or severe arrhythmia before screening: Including multifocal and frequent supraventricular tachycardia, ventricular tachycardia, etc.; or complicated with moderate to large pericardial effusion, severe myocarditis, etc.; or patients with unstable vital signs who require vasopressors to maintain blood pressure; * Presence of active infections requiring systemic treatment or uncontrolled infections within 3 months prior to screening; * Having received solid organ transplantation or hematopoietic stem cell transplantation within 3 months prior to screening; or having grade 2 or above acute graft-versus-host disease (GVHD) within 2 weeks prior to screening; * Positive for hepatitis B surface antigen (HBsAg) or hepatitis B core antibody (HBcAb) with peripheral blood hepatitis B virus (HBV) DNA level exceeding the normal range; positive for hepatitis C virus (HCV) antibody with peripheral blood hepatitis C virus (HCV) RNA level exceeding the normal range; positive for human immunodeficiency virus (HIV) antibody; positive for treponema pallidum antibody; * History of macrophage activation syndrome within 1 month prior to screening (except for those for whom the investigator has determined that safety risks are excluded after treatment); * History of previous CAR-T therapy (except for those for whom the investigator has determined that safety risks are excluded after treatment); * Presence of active pulmonary tuberculosis at the time of screening; * Having received any vaccination within 4 weeks prior to screening; * Positive result of blood pregnancy test; * A confirmed diagnosis of malignant diseases such as tumors prior to screening; * Participation in other clinical trials within 3 months prior to enrollment; * Other circumstances that the investigator deems inappropriate for participation in this study.