Myeloablative Conditioning, Prophylactic Defibrotide and Haplo AlloSCT for Patients With Sickle Cell Disease

Inclusion Criteria:

* Disease: Homozygous Hemoglobin S Disease, or Hemoglobin S B0/+ thalassemia, or Hemoglobin SC Disease, or Beta thalassemia intermedia/majora
* Patients must demonstrate one or more of the following Sickle Cell Disease Complications
* Clinically significant neurologic event (stroke) or any neurologic deficit lasting \>24 hours that is accompanied by an infarct on cerebral MRI
* Acute chest syndrome in the preceding two year period prior to enrollment that have failed, been non-compliant or declined hydroxyurea treatment, or prior to chronic RBC transfusion therapy, exchange transfusion or erythrocyte pheresis.
* Recurrent painful events (at least 3 in the 2 years prior to enrollment or prior to chronic RBC transfusion therapy, exchange transfusion or erythrocyte pheresis).
* Abnormal TCD study requiring starting on chronic transfusion therapy and/or exchange transfusions.
* At least one silent infarct lesion on a MRI scan of the head. Or (directly or probably related to SCD)
* Sickle Cell nephropathy;
* Splenic sequestration requiring RBC transfusion;
* Aplastic crisis requiring RBC transfusion;
* Avascular necrosis of the hip diagnosed by MRI;
* Two episodes or more of leg ulcerations;
* Recurrent priapism .
* Infant dactylitis.
* all patients must meet disease, age, organ function and donor criteria;

Exclusion Criteria:

* Patients who are receiving concomitant systemic anticoagulants and/or fibrinolytic therapies.
* Patients with a previously known hypersensitivity reaction to defibrotide.
* Females who are pregnant or breast-feeding are not eligible
* Patients with documented uncontrolled infection at the time of study entry are not eligible.
* Patients who have an unaffected HLA matched sibling donor willing to proceed to donation will not be eligible for this study.
* Karnofsky or Lansky (age appropriate) Performance Score \<50% (hemiplegia alone secondary to a previous stroke is not an exclusion)
* Demonstrated lack of compliance with medical care.
* Patients with clinically significant fibrosis or cirrhosis of the liver will not be eligible.
* Patients who have previously received a HSCT will not be eligible.
* Patients with contraindications to the use of defibrotide