SELECT-SLE: Biomarker-Guided CAR-T Target Selection for Refractory Lupus

Inclusion Criteria: * 1\. Age 18 to 70 years at consent. 2. Meets 2019 EULAR/ACR classification criteria for SLE, with total score \>= 10. 3\. Active refractory disease at screening, defined by SELENA-SLEDAI \>= 8, or at least one BILAG A domain, or at least two BILAG B domains, or active lupus nephritis with significant proteinuria and active urinary sediment. 4\. Inadequate response, intolerance, or contraindication to at least 2 prior standard systemic regimens, including at least 1 immunosuppressant or biologic used for SLE or lupus nephritis. 5. Demonstrable targetable biology and assignment to one protocol arm: CD19 arm for measurable CD19-positive B-cell / B-cell-dominant disease, or BCMA arm for BCMA-positive plasmablast / plasma-cell-dominant disease and/or persistent serologic activity after prior B-cell depletion. 6. If active lupus nephritis is present, biopsy-proven class III, IV, V, or mixed proliferative / membranous LN within the previous 24 months, or investigator confirmation that repeat biopsy is unsafe but the clinical picture strongly supports active LN. 7. Adequate organ function: hemoglobin \>= 8.5 g/dL, ANC \>= 1.0 x 10\^9/L, platelets \>= 50 x 10\^9/L, AST / ALT \<= 2.5 x ULN, creatinine clearance \>= 30 mL/min, bilirubin \<= 2.0 mg/dL unless otherwise explained, and LVEF \>= 50%. 8\. Adequate venous access and eligibility for leukapheresis. 9. Negative pregnancy test and agreement to use effective contraception for 12 months after infusion.…