Objective: To investigate the impact of cryopreservation duration of umbilical cord blood (UCB) on quality of hematopoietic stem cell and outcome of clinical transplantation.
Methods: 605 units of UCB which had been used in clinical transplantation were previously cryopreserved for 820 (88-2651) days in average. UCB was detected for total nucleated cell count, CD34+ cells count, cell recovery rate, cell viability and CFU-GM after thawing.
Results: No statistical correlation was found between cryopreservation duration and cell recovery rate, cell viability. CFU-GM decreased along with the extension of cryopreservation duration (P=0.011), ranging between 109.6 and 105.7/1 × 10⁵. There was no significant difference on hematopoietic reconstitution time, graft failure, acute GVHD and overall survival among groups with different cryopreservation duration.
Conclusion: Cryopreservation duration has no significant effect on cell recovery rate, cell viability and clinical transplantation outcome. Extension of cryopreservation duration may reduce CFU-GM of stem cells with fluctaion still in normal range. UCB could maintain cell viability and function to achieve satisfactory clinical transplantation outcome even when thawed after 3 to 7 years' cryopreservation.
目的: 探讨液氮冻存时间对脐血造血干细胞质量和临床移植效果的影响。
方法: 对上海脐血库已经应用于临床移植的605份脐血进行研究，脐血平均冻存时间为820（88～2651）d，测定脐血复苏之后的有核细胞、CD34+细胞数量、细胞回收率、细胞活力，粒-单核细胞集落形成单位（CFU-GM），结合脐血冻存时间、临床移植效果进行统计分析。
结果: 复苏后细胞回收率、细胞活力与冻存时间无显著相关性，CFU-GM平均（109.6～105.7）个/1×105，随冻存时间延长逐渐降低（P=0.011）。临床移植患者的造血重建时间、植入失败率、急性移植物抗宿主病、总体生存率与脐血冻存时间长短无显著相关性。
结论: 深低温冻存时间长短对脐血复苏后细胞回收率、细胞活力、临床移植效果无显著影响，冻存时间较长的脐血复苏后CFU-GM在正常标准范围内略有下降，保存3~7年的脐血仍能维持正常细胞活性和功能、达到良好的临床移植效果。