Stem Cell Transplantation After Reduced-Dose Chemotherapy for Patients With Sickle Cell Disease or Thalassemia

Inclusion criteria: All patients must: Have related donors who are identical at 6 human leukocyte antigens (HLA) loci (A, B and DR) by molecular typing Have a performance status from 0-2 Give written informed consent Patients with sickle cell disease should have 1 or more of the following: Acute chest syndrome requiring recurrent hospitalization or exchange transfusion Nonhemorrhagic stroke or central nervous system event lasting longer than 24 hours Recurrent vaso-occlusive pain (2 episodes or more per year) or recurrent priapism Sickle nephropathy (moderate or severe proteinuria or a glomerular filtration rate 30-50 percent of normal predicted value) Bilateral proliferative retinopathy and major visual impairment in at least 1 eye Osteonecrosis of multiple joints Patients with thalassemia should have 1 or more of the following: Transfusion dependence, defined as a transfusion requirement of greater than or equal to 6 units of packed red blood cells over the past 12 months Iron overload, defined as serum ferritin greater than 500 mcg/L in the absence of infection or biopsy-proven iron overload Presence of 2 or more alloantibodies against red cell antigens Exclusion criteria: Pregnancy Acute hepatitis (transaminases greater than 3 times the normal value) Cardiac ejection fraction less than 30 percent Severe renal impairment (glomerular filtration rate less than 30 percent of predicted normal value) Severe residual functional neurologic impairment (other than hemiplegia alone) Seropositivity for the human immunodeficiency virus (HIV)