A Clinical Study of YTS109 Cell in R/R Systemic Lupus Erythematosus

Inclusion Criteria: Subjects must meet all of the following inclusion criteria to be eligible for enrollment in this study: 1. Age ranges from 18 to 65 years old (including threshold), regardless of gender. 2. Meet the EULAR/ACR 2019 SLE Classification Criteri: Cohort 1: Refractory Lupus Nephritis: Defined as failure to achieve remission after treatment with corticosteroids and ≥2 immunosuppressants (e.g., CTX, tacrolimus, MMF, cyclosporine) and/or biologics, with urine protein/creatinine ratio (UPCR ≥1.0 g/g) , and renal pathology requirement scriteria: ISN/RPS 2003 Class III/IV proliferative lupus nephritis (or combined with type V features) , with ≤50% glomerulosclerosis. Cohort 2: Refractory Immune Thrombocytopenia: Requires treatment failure with: Failed treatment with at least 1 course of MP shock (1g for 3 days) or high- dose glucocorticosteroids (1mg/kg/d equivalent dose of glucocorticosteroids) in combination with 1 or more immunosuppressive agents. At least 2 consecutive routine blood tests for platelets less than 50×10\^9/L and \>30×10\^9/L were performed prior to enrolment. other non-SLE causes of thrombocytopenia, such as infections, myelosuppression and hypersplenism, were excluded. 3\. Essential Organ Function Criteria: 1. Bone marrow: Neutrophils ≥1×10\^9/L (within 2 weeks, excluding granulocyte colony-stimulating factor use). Hemoglobin ≥60 g/L. 2. Liver: ALT/AST ≤3×ULN (disease-related elevations permitted). TBIL ≤1.5×ULN (disease-related elevations permitted). 3. Renal: CrCl≥30mL/min (Cockcroft-Gault formula, excluding acute declines). 4. Coagulation: INR/PT ≤1.5×ULN. 5. Cardiovascular: Hemodynamic stability. 4. Fertile females or males with partners of childbearing age must use medically approved contraception or abstain during and ≥12 months post- treatment. Negative serum HCG test (within 7 days pre-enrollment) for fertile females; non-lactating. 5\. Voluntary participation with signed informed consent and compliance. Exclusions Criteria: Subjects who meet any of the following exclusion criteria will not be admitted to the study: 1. Severe drug allergies or hypersensitivity. 2. Uncontrolled/untreated infections (fungal, bacterial, viral, etc.). 3. CNS disorders (exceptions: epilepsy, psychosis, organic brain syndrome, cerebrovascular accident, encephalitis, CNS vasculitis). 4. Heart failure intolerance. 5. Congenital immunoglobulin deficiency. 6. Malignancy within 5 years (exceptions: localized cancers with negligible metastasis risk). 7. End-stage renal failure. 8. Subjects positive for: HBsAg / HBcAb with HBV DNA \> detection limit; HCV Ab + HCV RNA; HIV Ab; Syphilis test. 9. Deep vein thrombosis/pulmonary embolism within 6 months pre- screening. 10. Severe mental illness/cognitive impairment. 11. Participation in other clinical trials within 3 months pre-screening. 12. Use of immunosuppressants (within 5 half-lives) or biologics (within 4 weeks) pre-screening. 13. Pregnancy/breastfeeding or planned conception. 14. Other researcher-determined ineligibility.