A Reduced Toxicity Allogeneic Unrelated Donor Stem Cell Transplantation (SCT) for Severe Sickle Cell Disease

Inclusion Criteria

• •Patients must have sickle cell disease (genotype Hb SS or Sß° thalassemia), AND must have 1 or more of the following clinical complications related to Sickle cell disease:
• •1. A clinically significant neurologic event (stroke) or any neurologic defect lasting \>24 hours, that is accompanied by an infarct on cerebral MRI.
• •2. Minimum of two episodes of acute chest syndrome (defined as new pulmonary alveolar consolidation involving at least 1 complete lung segment associated with acute symptoms including fever, chest pain, tachypnea, wheezing or cough) despite adequate supportive care measures (example: asthma therapy, hydroxyurea).
• •3. History of severe pain episodes defined as 3 or more severe pain events per year in the 2 years prior to enrollment despite adequate supportive care measures and hydroxyurea trial (i.e. Hydroxyurea non-responders). Pain may occur in typical sites associated with vaso-occlusive painful events and cannot be explained by causes other than vaso-occlusion mediated by sickle cell disease.
• •4. Recurrent priapism.
• •5. Osteo-necrosis of multiple joints
• •6. Evidence of Pulmonary Hypertension as evidenced by Tricuspid Regurgitation jet velocity (TRV) \> 2.5 m/s on Echocardiogram.
• •7. Red cell allo-immunization (≥ 2 antibodies) during long term transfusion therapy.