Purpose: To analyze factors that affect the collection of peripheral-blood stem cells (PBSC) before transplant and the tempo of engraftment after transplant.
Patients and methods: A consecutive series of 243 patients with breast cancer (n = 87), malignant lymphoma (n = 90), multiple myeloma (n = 32), or other malignancies (n = 34) had PBSC collected following stimulation with colony-stimulating factors (CSFs) or after chemotherapy followed by CSF. Infusion of PBSC was performed following myeloablative chemotherapy with chemotherapy with or without total-body irradiation (TBI). Postinfusion CSFs were administered to 72 patients. An analysis of factors that influence CD34+ cell yield was performed by linear regression. Cox regression analysis was used to determine factors that affect the kinetics of granulocyte and platelet recovery following infusion of PBSC.
Results: Mobilization with chemotherapy followed by CSF, a diagnosis of breast cancer, absence of marrow disease, no prior history of radiation therapy, and fewer cycles of conventional-dose chemotherapy were associated with a higher average daily yield of CD34+ cells. In the multivariate analysis, the CD34 content of infused cells and the use of a posttransplant CSF influenced neutrophil recovery after infusion of PBSC. CD34 content was also important for predicting platelet recovery. The use of postinfusion CSF was associated with a significant delay in platelet recovery in patients who received less than 5.0 x 10(6) CD34+ cells/kg, but there was no discernable effect in patients who received greater than 5.0 x 10(6) CD34+ cells/kg.
Conclusion: Disease status and prior treatment influence the ability to mobilize PBSC. CD34 cell dose is an important predictor of engraftment kinetics after PBSC transplant, regardless of disease or mobilization technique. The use of postinfusion CSF improves neutrophil recovery, but at low CD34 doses can delay platelet recovery.