Direct Comparsion of Long-Term Culture-Initiating Cells in Bone Marrow, Umbilical Cord Blood and Peripheral Blood Stem Cells / 대한혈액학회지

ABSTRACT

BACKGROUND: Classically bone marrow (BM) is the major source of hematopoietic stem cells for the transplantation. Recently, hematopoietic stem cells circulating in peripheral nlood and umbilical cord stem cells have been widely accepted for use in high dose chmotherapy requiring hematopoietic stem cells support. Number if CFU-GM and CD34+ cells are routinely used to assess the engraftment potential of BM aspirates and leukapheresis harvests. However, these parameters predominantly reflect clonogenic cell activity which might only be relevant to short-term hematopoeitic reconstitution, and not necessarily reflect the hematopoeitic stem cell activity capable of sustained engraftment. Long-term culture system is regarded as a quantitative method of estimating hematopoietic stem cell activity in clinical samples. METHODS: We enumerated CFU-GM and CD34+ cells in G-CSF mobilized peripheral blood (MPB), BM and umbilical cord blood (UCB). We obtained the number of LTC-IC from each of these hematopoietic stem cell sources using the long-term culture system. These parameters have compared between the stem cell sources. RESULTS: CD34+ cells were detected in MPB, BM, and UCB at incidences of 2.27+/-1.58%, 0.74+/-0.55%, 1.24+/-0.24% of total mononuclear cells. The highest number of CD34+ cells were seen in UCB. The colony counts higher in UCB than in MPB and BM. Direct comparison of LTC-IC was made between three sources based on CD34+ cell counts. The total numbers of LTC-IC per 105 CD34+ cell were 713 for UCB, 263 for BM, 104 for MPB. These UCB was superior to BM and MPB by cell all three parameters; CFU-GM, CD34+, LTC-IC. CONCLUSION: We speculate that UCB should be better source of hematopoietic stem cell transplantation as well as gene therapy if it could be expanded.