Stem cell component therapy: supplementation of unmanipulated marrow with CD34 enriched peripheral blood stem cells

Eleven patients with hematologic malignancies and two with aplastic anemia were treated using unmanipulated marrow and immunoselected CD34(+) blood ce lls, Donors began G-CSF (10 mu g/kg) injections 1 day after undergoing bone marrow harvest. Blood stem cells were collected on day 5 of G-CSF, Periphe ral blood lymphocytes were depleted via CD34-positive selection, If, after marrow and blood harvest, less than 2.0 x 10(6) CD34 cells/kg were mobilize d, leukapheresis was repeated on day 6, Median time to an absolute neutroph il count greater than 500 mu l was day 10; transfusion-independent platelet count greater than 20000/mu l was day 13; average hospital discharge was d ay 14; and average inpatient hospital charges were 101 870 US dollars, Acut e GVHD grade II occurred in five of 13 patients. No patient developed grade III or IV acute GVHD, At a median follow-up of 10 months, no patient has d eveloped extensive chronic GVHD, Allografts of unmanipulated bone marrow su pplemented with G-CSF-mobilized and CD34 immunoselected blood cells may pre vent an increased risk of GVHD while preserving the rapid engraftment kinet ics of peripheral blood. Supplementation of marrow with CD34 enriched blood cells appears to result in rapid engraftment, early hospital discharge, lo wer inpatient charges, decreased regimen-related toxicity, and no apparent increase in GVHD.