Patients and normal donors undergoing apheresis to harvest cytokine-mobilized blood stem cells exhibit variable efficiencies of CD34+ stem cell and GM-CFC progenitor cell collection. An understanding of the factors underlying this variability might identify influences on the behavior of stem cells and strategies for more efficient stem cell collection. A preliminary analysis of patterns of stem and progenitor cell mobilization noted categories of increasing, decreasing and stable number of CD34+ cells and GM-CFC in the sequential apheresis products of each donor. However, values for the initial collection also varied widely and a discord between the number of CD34+ cells and GM-CFCs/collection was not unusual. The current study considers 267 cancer patients undergoing autologous collection. Their harvests showed relatively decreasing numbers of CD34+/mononuclear cells (MNC) as either the number of prior chemotherapy regimens the patients had received or the duration of time they had received the prior chemotherapy increased. In contrast, the median numbers of GM-CFCs/MNC in the harvests were unchanged for groups of patients who had received 1 and 2 prior chemotherapy regimens or had received chemotherapy for one to five and six to twelve months, and fell in those patients who had received more than two prior chemotherapy regimens or had received prior chemotherapy for more than 12 months. This shift in the structure of the stem cell compartment from more primitive stem cells to later progenitors resembles that reported to occur in mice with senescence (van Zant et al, Exp Hematol, 1997). A similar analysis of 60 allogeneic stem cell donors also demonstrated heterogeneity, albeit with higher median CD34+ cell and GM-CFC numbers, in the absence of prior therapy but potentially with a genetic basis, again not unlike the situation in mice with senescence. These data suggest that effects of genetic background in individuals, amplified by prior therapy in autologous donors, interact to influence the efficiency of blood stem cell collections.
|Original language||English (US)|
|Issue number||11 PART II|
|State||Published - 2000|
ASJC Scopus subject areas
- Cell Biology