Background: The effects of donor characteristics on CD34(+) cell dose remain controversial. Recently, we developed a novel haploidentical transplant protocol, in which mixture allografts of granulocyte colony-stimulating factor (G-CSF)-primed bone marrow (G-BM) and G-CSF-mobilized peripheral blood (G-PB) were used. The aim of this study was to investigate the effects of donor characteristics on CD34(+) cell dose in mixture allografts of G-BM and G-PB.
Methods: A total of 162 healthy adult donors, who underwent bone marrow harvest and peripheral blood collection between January 2009 and November 2010 in Peking University People's Hospital, were prospectively investigated. G-CSF was administered subcutaneously at a dose of 5 µg/kg once a day for 5-6 consecutive days. Bone marrow and peripheral blood stem cells were harvested on the fourth day and fifth day, respectively. A final total CD34(+) cell dose less than 2×10(6) cells/kg recipient body weight was considered a poor mobilization.
Results: Of the 162 donors, 31 (19.1%) did not attain this threshold. The obtained median CD34(+) cell doses in bone marrow, peripheral blood, and mixture allografts were 0.83×10(6)/kg, 2.40×10(6)/kg, and 3.47×10(6)/kg, respectively. Multiple regression analysis showed that donor age had a significant negative effect on CD34(+) cell dose in either G-BM, or G-PB, or mixture allografts of G-BM and G-PB. And a 1-year increase in age was associated with a 5.6% decrease in the odds of achieving mobilization cutoff. No significant correlation was found for donor gender, body mass index (BMI), and weight.
Conclusion: Donor age is the only factor among the four parameters, including age, gender, weight, and BMI, that influence CD34(+) cell dose in mixture allografts of G-BM and G-PB, and younger donors should be chosen to obtain sufficient CD34(+) cells for transplantation.