Klin Onkol 1999; 12(3): 91-96.
Abstract: Autologous blood stem cell transplantation to support high-dose chemotherapy has become comrnonplace for a variety of tumor types.Transplant physicians have become accustomed to rapid hematopoetic engraftment, but 10% - 40% of patients have delayed platelet engraftment (neutrophil recovery is prompt in nearly all patients). Rapidity of engraftment is directly correlated to the number of CD34+ cells infused per kilogram body weight. The optimal cell dose for rapid hematopoietic recovery for neutrophils (and in the majority of patients also for platelets) is 2.5x 106 CD34+cells/kg. Patients who, after repeated aphereses, do not reach this ideal cell dose (more than 2.5xl06 CD34+cells/kg) are defined as ‚hard-to mobilize‘ patients.
Strategies used by transplant centers in these bad mobilizers are :
- Do not performe this treatment strategy.
- Performe transplantation with a less than ideal CD34+ cell dose.
- Performe remobilization with the identical (identical regimen separated in time from the first mobilization usually yields the same number of CD34+ cells) or different mobilizing regimen.
For remobilization with different regimens, we can use:
- a) Remobilization with combination of chemotherapy plus cytokines.
- b) Remobilization using dose-escalation of available cytokines.
- c) Remobilization using the combination of early- and late-acting cytokines (PIXY 321 or G-CSF in combination with stem cell
factor, interleukin 3, GM-CSF, thrombopoetin, erythropoetin, etc). - d) Remobilization using a different form ofG-CSF.
- Performe bone marrow harvesting.
Detailed mobilization schemes recommendation as well as the expense and practicality of all these options,are discussed.
