Inclusion Criteria:

• 1. Ages 18 to 50 years old. 2. Meet at least 4 of 11 American College of Rheumatology (ACR) Classification criteria for SLE (see Appendix 1).

  3. Able to give informed consent. 4. HLA matched sibling donor available. 5. Meet one of following three:

  1. For lupus nephritis, participants must fail pulse cyclophosphamide (500 to 1000 mg/m2 monthly for a minimum of 6 months). Failure is defined as meeting criteria to be considered as BILAG (Appendix 4) renal category A. If indication for HSCT is nephritis, a renal biopsy must be obtained and document either class III or IV glomerulonephritis.
  2. For visceral organ involvement other than nephritis, participants must be BILAG cardiovascular/respiratory category A, vasculitis category A, or neurologic category A and must fail at least 3 months of oral or IV cyclophosphamide and be corticosteroid dependent. Steroid dependence being defined as at least 3 months of steroid therapy and inability to wean corticosteroid to less than 20 mg/day of prednisone or equivalent.

  3. For cytopenias that are immune mediated, participants must be BILAG hematologic category A. Participants must have an inability to maintain platelets > 15,000, an inability to prevent active bleeding without transfusion, an inability to maintain hemoglobin > 7.0, or an inability to prevent cardiovascular disease without transfusion. In addition, participants must fail corticosteroids (either oral prednisone > 0.5 mg/kg/day for more than 6 months or pulse methylprednisolone for at least one cycle of three days), be refractory to IVIG, and at least one of the following: azathioprine at 2 mg/kg/day for at least 3 months, mycophenolate mofetil 2 grams daily for more than 3 months, cyclophosphamide intravenously or orally for at least 3 months, or cyclosporine at least 3 mg/kg/day for at least 3 months, danazol for at least 3 months, or splenectomy.

     Exclusion Criteria:

• 1. HIV positive. 2. Ongoing malignancy except localized basal cell or squamous skin cancer. Other malignancies for which the participant is judged to be cured by local surgical therapy, such as head and neck cancer, or stage I or II breast cancer will be considered on an individual basis by the investigators doing the final screening for participant qualification.

  3. Positive pregnancy test, inability or unwillingness to pursue effective means of birth control, failure to willingly accept or comprehend irreversible sterility as a side effect of therapy.

  4. Psychiatric illness or mental deficiency making compliance with treatment or informed consent impossible.

  5. DLCO < 45% of predicted unless attributed solely to active lupus. 6. Resting LVEF < 40% unless due to active lupus. 7. Known hypersensitivity to E. Coli derived proteins. 8. Transaminases greater than 2 times normal unless due to active lupus. 9. Any illness that in the opinion of the investigator would jeopardize the ability of the Patient to tolerate this treatment.