[Measures for Maintaining the Vitality of Peripheral Blood Hematopoietic Stem Cells in vitro].

OBJECTIVE: To explore the maintaining measures for the vitality of hematopoietic stem cells (HSC) in vitro, so as provide technical support for ultra long distance transport of HSC collected from unrelated donors. METHODS: Peripheral blood hematopoietic stem cells (PBHSC) were treated by different methods according to various groups, then stored at 4 ℃ in the refrigerator. The percentage of CD34+ cells, relative cell activity, relative cell proliferation rate, relative colony-forming rate, oxygen fraction and intracellular reactive oxygen species (ROS) were detected at 0, 24, 48 and 72 h after storage of PBHSC respectively. RESULTS: The percentage of CD34+ cells during 72 h storage did not altered. Along with the prolonging of storage time, the relative cell activity, relative cell proliferation rate and relative colony-forming rate gradually decreased in untreated PBHSC(control group), the related coefficients were -0.796, -0.883 and -0.815 respectively. Plasma dilution, antioxidants and oxygenation could improve the relative cell activity and relative cell proliferation rate, but oxygenation could decrease the relative colony-forming rate of PBHSC. The combination of 2 or 3 factors showed stronger protection effects on PBHSC. The intracellular level of ROS decreased gradually with the prolonging of storage time. Oxygenation of PBHSC could increase oxygen fraction, and also increase the intracellular level of ROS at the same time. The addition of antioxidants could reduce the level of ROS. CONCLUSION: The percentage of CD34+ cells can not serve as the indicator of PBHSC vitality. Plasma dilution, oxygenation and antioxidants can increase the survival and viability of PBHSC, but oxygenation can increase the intracellular ROS level and impair colony-forming ability of PBHSC. The combination of multiple factors can maintain the vitality of PBHSC better.

[Safety comparison of mobilization and collection of hematopoietic stem cells between related and unrelated donors].

The study was aimed to compare the safety of hematopoietic stem cell mobilization and collection in related donors providing bone marrow and peripheral blood stem cells and in unrelated donors providing peripheral blood stem cells only. 100 related donors from September 2005 to August 2006 at Institute of Hematology & People Hospital, Peking University, and 71 unrelated donors from November 2003 to December 2007 in Data Bank of Chinese Hematopoietic Stem Cell Donor Beijing Management Center, were observed in process of bone marrow and peripheral blood stem cell mobilization, collection, and follow-up. The change of hematologic parameters (white blood cell count, platelet count and hemoglobin level) and the side effects were recorded and evaluated on months 1, 3 and 6 as well as annually after PBSC donation. During follow-up, long-term side effects and life quality were investigated by questionnaires. The results showed that the total MNC count of bone marrow and PBSC from related donors was 6.70 (4.11 - 12.23) x 108/kg, and the total CD34(+) cell count was 3.40 (1.61 - 13.57) x 106/kg; the total MNC count of PBSC from unrelated donors was 6.69 (3.35 - 11.48) x 108/kg, and the total CD34(+) cell count was 3.50 (1.15 - 11.60) x 106/kg. The main side effect of mobilization was bone pain, reported in 47.0% of the related donors and in 43.7% of unrelated ones, the main side effect of collection was paresthesia, reported in 25.0% of the related donors and in 29.6% of unrelated ones, there was no significant difference on side effects between related and unrelated donors during mobilization and collection of hematopoietic stem cells, all donors could endure these side effects, and no donor discontinued G-CSF administration because of side effects. After collection, the hemoglobin level of related donors was lower than that of unrelated donors [(125.8 ± 20.2) g/L vs (143.2 ± 20.1) g/L] (p < 0.05) because of bone marrow and peripheral blood collection, and the platelet count of unrelated donors were lower than that of related donors [(126.2 ± 57.2) x 109/L vs (162.4 ± 72.9) x 109/L] (p < 0.05) because of more than two times of collection. There was no significant difference on hematologic parameters between two groups during long-term follow-up, and the majority of the donors reported were in good or very good health. It is concluded that the donation proved from related and unrelated donors is safe to mobilize hematopoietic stem cells for allogeneic transplantation. Long-term monitoring of healthy PBSC donors remains important to guarantee the safety standards of bone marrow and peripheral blood stem cell mobilization and collection, including comprehensive medical examination before mobilization and collection, careful manipulation during collection, long term follow up after collection and so on.