Minimizing Toxicity in HLA-identical Sibling Donor Transplantation for Children With Sickle Cell Disease

"The conditioning regimen (SUN regimen) will consist of alemtuzumab daily for 5 days (total dose 1 mg/kg) and low dose total body irradiation (TBI) 300 cGY on Day -2 with gonadal shielding if possible. The HSCT graft will be G-CSF mobilized PBSCs with minimum CD34+ of 5 x106/kg recipient weight, goal of 10 x 106/kg (no upper limit). A peripheral blood stem cell (PBSC) graft was selected as it engrafts faster than bone marrow and would lead to shorter period of neutropenia and infection and less thrombocytopenia and need for platelet transfusion.~GVHD prophylaxis will be sirolimus with a loading dose 3 mg/m2 on day -1. Sirolimus will be continued at 1 mg/m2/day starting on day 0 and dose adjusted to maintain a target trough level 5-15 ng/mL for the first 3 months and 5-10 ng/mL for the remainder of the first year."