Universal CAR-T Cell Therapy for Refractory Lupus Nephritis

Inclusion Criteria: * Aged 18-65 years; both genders eligible. * Subjects diagnosed with lupus nephritis. * Previous treatment outcomes were unsatisfactory. * Diagnosis of active nephritis type III or IV with or without type V according to 2018 International Society of Nephrology and Society of Renal Pathology (ISN/RPS) criteria. * NIH Activity Index \> 2 and elevated chronicity index. * Urine protein: creatinine ratio (UPCR) ≥ 1.0 g/g, or 24-hour urine protein ≥ 1.0 g, with or without active urine sediment with red blood cell casts. * Receiving hormones with or without antimalarials. * SLEDAI-2K score ≥ 6. * Antinuclear antibody positive, and/or anti-ds-DNA antibody positive, and/or anti-Smith antibody positive. * Positive expression of CD19 on B cells in peripheral blood. * Agrees to use double barrier methods, condoms, oral or injectable contraceptives, or intrauterine devices during the study period and for one year after taking the study medication. * Provides written informed consent. Exclusion Criteria: * History of solid organ transplantation. * Malignant tumor within the last two years. * Positive for Hepatitis B surface antigen (HBsAg) or Hepatitis B core antibody (HBcAb), with peripheral blood Hepatitis B virus (HBV) DNA detected as positive; positive for Hepatitis C virus antibodies, with peripheral blood Hepatitis C virus RNA detected as positive; positive for Human Immunodeficiency Virus (HIV) antibodies; positive for Cytomegalovirus (CMV) DNA; positive for syphilis. * Primary immunodeficiency (congenital or acquired). * Severe cardiac disease. * History of psychiatric disorders or history of psychotropic drug abuse, with no history of withdrawal. * Allergic constitution or a history of severe allergies. * Pregnant or breastfeeding women.