Viability and Quantification of Progenitor Cells in Venesected Blood from Patients Receiving Escalated-Dose Epirubicin and Cyclophosphamide with G-CSF for Lymphoma: Potential Role in Further Increasing Dose-Intensity

We assessed the concentration of haemopoietic progenitors in peripheral blood in six patients with de novo intermediate grade non-Hodgkin's lymphoma receiving multiple cycles of escalated dose epirubicin and cyclophosphamide on day 1 followed by 5ug/kg of G-CSF (filgrastim) on days 2-14. Specimens were taken at days 12, 15 and 18 in cycles 1 and 2 and on day 15 for cycles 3-6. Progenitor numbers were maximal on day 15 in cycles 1 and 2. The median number of granulocyte-macrophage colony forming cells (GM-CFC) and CD34+ cells on day 15 of cycles 1 and 2 was 3.8 × 104/ml and 11 × 104/ml, respectively. A 600ml venesection at this time would contain a median of 36 × 104 GM-CFC/kg (range 25-47) and 1.04 × 106 CD34+ cells/kg (range 0.73-1.4), based on individual patient weights. Day 15 progenitor numbers were maintained for the first 3 cycles but tended to fall thereafter. The viability of the progenitors collected in whole blood and stored at 4×C for various time intervals was also assessed. The median percent...