CD19 CAR T-Cell Therapy for Refractory Systemic Lupus Erythematosus

Inclusion Criteria: * Age 16 to 55 years, male or female * Diagnosis of systemic lupus erythematosus (SLE) according to the 2019 EULAR/ACR classification criteria with a total score ≥ 10 * SLEDAI-2K score ≥ 8 at screening (with at least 4 points derived from laboratory parameters; excluding points attributable to central nervous system involvement) * Positive antinuclear antibody (ANA ≥ 1:80) OR positive anti-dsDNA OR positive anti-Sm antibody at screening or documented in medical history Refractory systemic lupus erythematosus or refractory lupus nephritis defined as one of the following: Refractory SLE: \- Failure to achieve adequate response, partial response, or stable disease control after ≥ 6 months of standard-of-care therapy (documented compliance). Standard therapy includes corticosteroids plus hydroxychloroquine and at least two of the following: calcineurin inhibitors, cyclophosphamide, mycophenolate mofetil, azathioprine, or B-cell-targeted therapy (e.g., rituximab, belimumab). Refractory Lupus Nephritis: * Persistent active lupus nephritis after two induction regimens, including intravenous cyclophosphamide and mycophenolate mofetil administered for ≥ 6 months (with or without calcineurin inhibitors, rituximab, or belimumab), AND: * Histopathologic confirmation of Class III or Class IV lupus nephritis, with or without Class V (ISN/RPS 2003 classification); isolated Class V is excluded * Proteinuria \> 1 g/24 hours OR urine protein-to-creatinine ratio \> 1 m…