Peripheral blood stem cell autotransplantation in treatment of childhood cancer

The levels of circulating hematopoietic progenitor cells were measured sequentially in eight children receiving chemotherapy for acute leukemia or neuroblastoma. Significant increases in the progenitor levels (up to 50-fold in CFU-GM numbers) were observed during post-chemotherapy cytopenia in all cases, but differences among individuals in the kinetics of recovery of less committed progenitors (CFU-mix) contrasted with the synchronized-mode of expansion of committed progenitors (CFU-GM). Peripheral blood cells were collected by repeated continuous-flow leukaphereses from three of the children during post-chemotherapy expansion of the progenitor pool and were cryopreserved after fractionation procedures. Infusion of these stored cells into the patients after marrow-ablative chemotherapy established trilineage hematopoiesis. This use of stem cell rescue should be useful as an alternative to bone marrow transplantation and extends the application of cure-oriented salvage therapy to childhood cancers.