CORRELATION ANALYSES BETWEEN CD34+ CELLS AND CLONOGENIC PROGENITORS MOBILIZED INTO THE PERIPHERAL-BLOOD BY IL-3 + GM-CSF FOLLOWING POLYCHEMOTHERAPY IN CANCER-PATIENTS

Hemopoietic progenitor cells were recruited into the peripheral blood by the combined sequential administration of rhIL-3 and rhGM-CSF following chemotherapy consisting of etoposide (VP16), ifosfamide and cis-platin (VIP) in 32 patients with a total of 46 treatment cycles. Control patients were treated with GM-CSF or without cytokines. Peripheral blood progenitor cells (PBPCs) were evaluated by their expression of the CD34 antigen as well as by their colony forming capacity (CFU-GM, BFU-E, CFU-Meg, CFU-GEMM). Correlation analyses between CD34+ cells and clonogenic progenitors revealed that rising CD34+ cells did not reflect the absolute numbers of clonogenic progenitor cells, with the exception of myeloid progenitors (CFU-GM) in the GM-CSF treated group of patients and megakaryocytic progenitors (CFU-Meg) in the patients given IL-3 + GM-CSF. Moreover, CFU-GM correlated well with peripheral blood mononuclear cells independent of any cytokine administration. These findings might be helpful in defining the time of optimal PBPC harvest for autografting or for hemopoietic support following high-dose chemotherapy.