PRIMARY HYPOTHESIS: T cell depletion utilizing the CliniMACS device will allow more precise, specific and controlled graft engineering of peripheral blood stem cells from unrelated and partially matched related donors without an increase in relapse or graft rejection and grade III or IV acute graft vs. host disease (GVHD).
SECONDARY HYPOTHESIS: Use of the CliniMACS device will allow defined levels of T cell depletion to reflect the risk of severe GVHD in the donor/recipient pair.
Thus, patients with a relatively lower risk of severe GVHD will be assigned to Stratum 1 and receive a graft with lesser T cell depletion and a defined level of reinfused T cells. Patients with higher risk of severe GVHD or for whom there is no perceived clinical benefit of GVHD will be assigned to Stratum 2 and receive a more T cell-depleted graft.
Conditioning of the patient (except immunodeficiencies) includes :
* Thiotepa 5 mg/kg days for 2 days
* Cyclophosphamide 60 mg/kg days for 2 days
* Total body irradiation 200 cGy given twice a day for 3 days
Following conditioning patient's will receive stem cells that have been processed using the CliniMACS device. This processing is done in the stem cell laboratory at The Children's Hospital of Philadelphia. The Stem Cell Lab is accredited by the Foundation for the Accreditation of Cellular Therapy (FACT) and maintain complete standard operating procedures (SOP's) and procedure records.
Processing of cells using the CliniMACS will occur in accordance with the Investigator Brochure and Technical Manual following the laboratory SOPs and using aseptic technique. The CHOP Stem Cell Lab has extensive prior experience with automated cell processing technologies, including the CellPro Ceprate device and the Isolex 300i.
