This study is looking at how safe and effective mesenchymal stem cells (MSCs) are for adults with systemic lupus erythematosus (SLE), a disease where the immune system attacks its own tissues, causing inflammation. MSCs are special cells from umbilical cords, which connect a baby to its mother in the womb. The study will compare patients getting MSCs plus their usual treatment to those getting a placebo (a fake treatment) plus usual treatment.

The trial is "double-blind," meaning neither the doctor nor the patient knows if the real drug or placebo is given. Participants will get one dose through an IV (intravenous) infusion, where the treatment goes directly into the vein.

To join, you must be 18-65 years old and have current SLE symptoms. You cannot join if you have active brain lupus, need dialysis, or have certain infections or health problems.

• Study involves a single IV infusion and regular monitoring.
• Participants will continue their standard treatment throughout.
• The trial is randomized and double-blind to ensure fairness and accuracy.