A Comparative Study of the Phenotype and Proliferative Capacity of Peripheral Blood (PB) CD34+ Cells Mobilized by Four Different Protocols and Those of Steady-Phase PB and Bone Marrow

Peripheral blood (PB) CD34+ cells from four commonly used mobilization protocols were studied to compare their phenotype and proliferative capacity with steady-state PB or bone marrow (BM) CD34' cells. Mobilized PB CD34+ cells were collected during hematopoietic recovery after myelosuppressive chemotherapy with or without granulocytemacrophage colony-stimulating factor (GM-CSF) or granulocyte colony-stimulating factor (G-CSF) or during G-CSF administration alone. The expression of activation and lineage-associated markers and c-kit gene product were studied by flow cytometry. Proliferative capacity was measured by generation of nascent myeloid progenitor cells (granulocyte-macrophage colony-stimulating factor; CFU-GM) and nucleated cells in a stroma-free liquid culture stimulated by a combination of six hematopoietic growth factors (interleukin-l (IL-l), IL-3, IL-6, GM-CSF, G-CSF, and stem cell factor). G-CSF-mobilized CD34' cells have the highest percentage of CD38cells ( P < .0081), but otherwise, CD34+ cells from different mobilization protocols were similar to one another in their phenotype and proliferative capacity. The spectrum