自体外周血干细胞动员中测定CD34^＋Thy—1＋细胞的意义

目的：确切评估动员后外周血干细胞（ＰＢＳＣ）水平的变化，及时指导临床选择最佳采血时机。方法：用流式细胞术测定化疗和粒细胞集落刺激因子（Ｇ－ＣＳＦ）联合动员时外周血ＣＤ３４＋Ｔｈｙ－１＋细胞含量的变化，同时用体外集落培养方法评价外周血祖细胞（ＰＢＰＣｓ）的克隆形成能力。结果：动员后循环血中ＣＤ３４＋Ｔｈｙ－１＋细胞、ＣＤ３４＋细胞和克隆形成细胞（ＣＦＣ）含量分别增高４８．６倍、５０．０倍和５３．１倍，高峰时间在化疗后第１２～１４天（注射Ｇ－ＣＳＦ的第６～８天）；外周血单个核细胞中ＣＤ３４＋Ｔｈｙ－１＋细胞、ＣＤ３４＋细胞的比例分别增高１３．８倍和１０．５倍；动员的早期阶段，ＣＤ３４＋细胞中Ｔｈｙ－１＋细胞比例最高。结论：联合应用化疗和Ｇ－ＣＳＦ对ＰＢＰＣｓ，尤其对早期干／祖细胞具有显著动员作用；用流式细胞术检测ＣＤ３４＋Ｔｈｙ－１＋细胞可及时指导临床准时采集ＰＢＳＣ。

The implication of circulating CD 34 Thy 1 cells measurement during autologous peripheral blood stem cell mobilization

OBJECTIVE: To estimate the amount of peripheral blood stem cells(PBSC) right during mobilization and determine the optimal time for PBSC collection. METHODS: A serial measurement of circulating CD34+ Thy-1(+) cells were carried out during PBSC mobilization by chemotherapy and granulocyte colony stimulating factor(G-CSF) using dual-color direct immunofluorescence flow cytometry. Colony-culture in vitro was performed at the same time to evaluate the clonogenic capacity of the peripheral blood progenitor cells (PBPCs). RESULTS: Circulating CD34+ Thy-1(+) cells, CD34+ cells and colony-forming cells increased by 48.6-, 50- and 53.1- fold, respectively, after mobilization. The peak levels were reached at 12 approximately 14 days after chemotherapy. The proportion of CD34+ cells and the candidate stem cells, CD34+ Thy-1(+) subset, in mononuclear cells (MNCs) exceeded baseline by 10.5- and 13.8- fold, respectively. The percentage of CD34+ cells coexpressing Thy-1 was highest in the earlist phase of mobilization. CONCLUSION: PBSCs, especially primitive progenitor cells, increased significantly during mobilization with chemotherapy and G-CSF. Flow cytometric assay of circulating CD34 Thy-1(+) cells promptly provides a more reliable indicator for clinical collection of PBSC.