Optimizing the timing of chemotherapy for mobilizing autologous blood hematopoietic progenitor cells

BACKGROUND: Postchemotherapy mobilization results were reviewed in patients undergoing apheresis before planned autologous hematopoietic progenitor cell (HPC) transplantation to improve the timing of collection procedures. STUDY DESIGN AND METHODS: A total of 135 attempts to collect autologous HPC were studied in 132 unique patients with lymphoid malignancies (nonHodgkin's lymphoma, multiple myeloma, and Hodgkin's disease). Chemotherapy mobilization regimens included cyclophosphamide (n = 59), ICE (n = 46), or other regimens (n = 30). Granulocyte-colony-stimulating factor (CSF) was administered once daily at a dose of 5 pg per kg starting 2 days after the last dose of chemotherapy; granulocyte-macrophage-CSF was added at a daily dose of 5 pg per kg 6 days later. Apheresis was initiated when the blood CD34+ content was more than 20 per pL. RESULTS: In an initial cohort of 37 patients, 27 percent required apheresis during the weekend. An optimized timing for chemotherapy mobilization was developed based on retrospective data; prospective implementation of the new algorithm reduced the incidence of weekend apheresis to 13 percent in the subsequent 98 consecutive patients (p < 0.05). A median of 9 x 10(6) (range, 0.4 x 10(6)-96 x 10(6)) CD34+ cells per kg was collected from the entire cohort of 135 patients after a mean of 1.8 days of apheresis. Apheresis was initiated following a median (+/- SD) of 10 +/- 2.7 days of cytokines. CONCLUSION: In the majority of patients, the first day of apheresis occurred 11 to 13 days after the last dose of chemotherapy with a variety of different chemotherapy regimens. Administering the last dose of chemotherapy on Thursday or Friday versus Monday, Tuesday, or Wednesday was associated with a 77 percent lower incidence in the frequency of weekend apheresis collections (p < 0.001).