总结血细胞分离机大容量白细胞单采术(large-volume leukapheresis, LVLs)采集小儿外周血干细胞(peripheral blood stem cell，PBSC)的经验，探讨采集效果及其影响因素。

中山大学附属第二医院儿科造血干细胞移植中心自1999年1月至2007年12月采用CS 3000 Plus血细胞分离机，选择儿童单个核细胞(MNC)收集程序，进行40例患儿大容量外周血干细胞采集。采取回顾性分析法分析单个核细胞采集量与采集效率及其影响因素和对外周血象与电解质的影响，以及采集不良反应发生率与机器常见报警(故障)。

对40例个体大容量外周血干细胞采集共计76次。其中，采集1次为5例，3次为1例，其余均采集2次。每次循环3~4倍血容量，单个核细胞采集效率平均为45. 2%(30.0%～112. 0%)，收集单个核细胞中位数为2. 5(1.2~6.5)×10⁸/kg，CD₃₄⁺细胞中位数为3. 5(2. 7~14. 9)×10⁶/ kg,后两者间有良好相关性(r=0. 78,P<0. 05).单个核细胞采集量与总处理血容量呈正相关(r=0. 45，P<0. 05)，与采集前外周血白细胞、外周血单个核细胞和外周血CD₃₄⁺细胞数呈显著正相关(r=0. 60，P< 0. 05)；(r=0. 68，P<0. 05)；(r=0. 75,P<0. 05)。采集后，外周血血红蛋白(Hb)和血小板(PLT)下降，第2次采集后与采集前比较，差异有显著意义(P<0.05)。采集大容量外周血干细胞前、后，个体的电解质水平变化比较，差异无显著意义(P>0.05)。76例次大容量外周血干细胞采集过程中，发生相关不良反应14例次(18. 4%，14/76)，机器出现报警或故障67例次(88. 2%,67/76)，处理后均顺利完成采集。

应用血细胞分离机大容量白细胞单采术采集小儿外周血干细胞的方法可靠，采集过程安全，可收集足量造血干(祖)细胞。适当增加处理血容量、改善动员效果，可提高单个核细胞采集率。

To summarize the experiment of large-volume leukapheresis(LVLs)for peripheral blood stem cell(PBSC)collection in children by blood cell separator to investigate the efficacy and variability of peripheral blood stem cell harvests.

Seventy-six large-volume leukapheresis were performed using CS 3000 plus cell separator with SVCH separation clip and special program in 40 patients(donors)whose median age and body weight were 8 years(range 2~18)and 22 kg(range 9. 0~45). The number of mononuclear cell(MNC)and CD₃₄⁺ cell collected, the collection efficiency(CE)of mononuclear cell components and electrolyte in peripheral blood, and adverse events were recorded and analyzed.

In 76 peripheral blood stem cell collection procedures, the time performed was only once in five receivers, third times in one receiver and the twice in the others. A median of 3. 5(3. 0~4. 5)times of blood volume was processed per session. The median collection efficiency of mononuclear cell was 45. 2%(range 30. 0%~112. 0%). The median cell collected of mononuclear cell and CD₃₄⁺ was 2. 5(1. 2~6. 5)× 10⁸/kg and 3. 5(2. 7~14. 9)× 10⁶/kg, and a significant correlation was shown between them. On univariate analysis, variables that positively influenced collection of mononuclear cell yield were the processed blood volume(r=0. 45, P<0. 05), peripheral blood leukocytes(r=0. 60, P<0. 05), mononuclear cell peripheresis(r=0. 68, P<0. 05)and CD₃₄⁺ cell peripheresis(r=0. 75, P<0. 05), respectively. The hemoglobin(Hb)and platelet(PLT)count in the peripheral blood decreased after apheresis, especially after the second time apheresis(P<0. 05). But little change was observed in Serum electrolyte level. A total of 14(18. 4%)adverse events and 67(88. 2%)technical problems out of 76 procedures were recorded, and large-volume leukapheresis was well tolerated by all children.

These data suggested that large-volume leukapheresis was safely and effectively applied to children, even those with low body weight, to collect adequate peripheral blood stem cell for transplantation. Improved mononuclear cell yield could be achieved by increasing blood volume and G-CSF pre-treatment.