Factors predicting peripheral blood progenitor cell collection from pediatric donors for allogeneic transplantation.

BACKGROUND AND OBJECTIVES: Although several studies have reported on the use of children as donors for peripheral blood progenitor cells (PBPC), no specific characteristics have been identified as predictors of PBPC collection in this population. In this study we analyzed predictive factors for PBPC collection in pediatric donors. DESIGN AND METHODS: We retrospectively analyzed factors predicting the yield for a target CD34+ cell dose of > or =4x10(6)/Kg donor or recipient body weight, in 105 aphereses from 76 healthy pediatric donors (36 boys and 40 girls) included in the Spanish National Donor Registry. Mobilization consisted of granulocyte colony-stimulating factor (G-CSF) in single doses of 10 microg/kg per day subcutaneously for 4 or 5 days. Apheresis started after the fourth dose of G-CSF. RESULTS: Median age and body weight were 10 years (range 1-18) and 42 kg (range 9-89), respectively. The median number of CD34+ cells/kg recipient body weight was 4.22 (range 0.1-32). On multivariate analysis variables that had a significant negative impact on the CD34+ cell yield, considering the recipient's body weight were the total blood volume processed (regression coefficient (RC): 0.41, 95% CI: 0.21-0.81; p=0.01) and day of apheresis other than first (RC: 0.16, 95% CI: 0.07-0.34; p<0.0001). When considering donor's body weight the variables that positively influenced collection were younger age (RC: 6.79, 95% CI: 1.57-29.25; p<0.01) and large volume leukapheresis (RC: 3.33, 95% CI: 1.13-9.77; p<0.02). INTERPRETATION AND CONCLUSIONS: Our data suggest that pediatric donors mobilized by G-CSF may donate sufficient numbers of CD34+ cells for allogeneic transplantation. The variables that influenced the yield were the donor's age, blood volume processed and the first day of the apheresis.

Induction of a hypercoagulability state and endothelial cell activation by granulocyte colony-stimulating factor in peripheral blood stem cell donors.

In June, 1997, we initiated a prospective study to analyze the effect of granulocyte colony-stimulating factor (G-CSF) on coagulation system in peripheral blood stem cells (PBSC) donors following G-CSF administration. Since, 25 consecutively healthy donors received G-CSF (filgrastim) to mobilize and collect PBSC and 20 donors were finally included in the study. Blood samples were collected immediately before starting G-CSF and prior to PBSC collection to analyze the following parameters: prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, hypercoagulability markers (D-dimer, TAT complex, F1 + 2), natural anticoagulants (antithrombin, protein C, protein S), endothelial activation markers [von Willebrand factor antigen (vWF:Ag) and angiotensin converting enzyme (ACE)], and resistance to activated protein C. We found a significant increase in F1 + 2 and D-dimer while a significant decrease of antithrombin and protein C activity was evidenced. Regarding endothelial cell activation markers, a significant increase of vWF:Ag with a slightly significant decrease of ACE were also observed. Therefore, in PBSC donors receiving G-CSF our results reveal activation of both coagulation and endothelial cells that could favor the developing of thrombotic events. In consequence, a careful monitoring should be considered in those cases with risk factors for thrombosis.

Analysis of factors associated with low peripheral blood progenitor cell collection in normal donors.

BACKGROUND: Predictive factors of the response to rHuG-CSF in normal donors have not been extensively studied. STUDY DESIGN AND METHODS: We analyzed factors influencing CD34+ cell yield in the 1st day of collection in 261 healthy donors from the Spanish National Donor Registry. The median age was 38 years (range, 2-72). The median dose of rHuG-CSF was 10 microg per kg per day (range, 5-20) over 4 days. In 103 donors (40%), <4 x 10(6) per kg CD34+ cells were collected. The variables that were analyzed included age, sex, weight, basal complete blood cell count, dose, type of rHuGCSF and schedule of administration, and maximum WBC count before apheresis. RESULTS: By univariate analysis, the maximum WBC count (<50 vs. >or=50 x 10(9)/L, p = 0.004), advanced age (p = 0.008), and number of daily rHuG-CSF doses (one vs. two; p = 0.01) correlated with the number of CD34+ cells collected. By multivariate analysis, donors age (<38 vs. >or=38 years; p = 0.014) and a single daily dose of rHuG-CSF (p = 0.005) were the two variables that significantly predicted a low CD34+ cell yield. CONCLUSION: Donors' age, with a threshold of 38 years or more, and the rHuG-CSF schedule are the factors that significantly affected CD34+ cell mobilization and collection in healthy donors.

Second mobilization and collection of peripheral blood progenitor cells in healthy donors is associated with lower CD34(+) cell yields.

We have retrospectively evaluated the results of two cycles of mobilization and collection of peripheral blood progenitor cells (PBPC) from 46 healthy donors included in the Spanish National Donor Registry. Mobilization involved the administration of granulocyte colony-stimulating factor (G-CSF) at a median dose of 10 microg/kg per day, and apheresis was begun after the fourth dose of G-CSF in both cycles. The median interval between both mobilizations was 187 days (range, 7-1428 days). The incidence and types of side-effects were similar after both donations, with 25 and 26 donors developing some toxicity after the first and second donations, respectively. The median number of CD34(+) cells collected was higher after the first mobilization than after the second (5.15 versus 3.16 x 10(6)/kg, respectively; p = 0.05), and 29 donors yielded fewer CD34(+) cells after the second mobilization (p = 0.018). A lower proportion of donors yielded CD34(+) cell counts >4 x 10(6)/kg after the second cycle than after the first (52% versus 76%, respectively; p = 0.057). Our study shows that second rounds of PBPC collection from normal donors are well tolerated but are associated with a significantly reduced number of CD34(+) cells collected when the same mobilization scheme is used.