Marx G, Blankenfeld A, Gorodetsky R, BarShany S
Magen David Adom Blood Services, Tel Hashomer, Israel.
Transfusion. 1991 Oct;31(8):743-7. doi: 10.1046/j.1537-2995.1991.31892023501.x.
White cells (WBCs) constitute a significant contaminant of platelet concentrates (PCs). Various technologies, including apheresis and filtration, are currently being developed to minimize the carryover of WBCs into platelets. The aim is to reduce contamination of less than 10(8) WBCs per platelet unit. As part of quality control monitoring of the blood bank operations, the centrifugation protocols employed in the preparation of platelet-rich plasma (PRP) have been evaluated for their impact on the WBC content of the PCs. The WBC content, which is expressed throughout the PRP volume as well as in the PC, reflects the degree of braking. For example, after centrifugation (2500 rpm, 4 min) of whole blood into packed red cells (RBCs) and PRP, braking-induced mixing increases the WBC content of the expressed PRP. Variations in the braking rates of the centrifuges used also correlate with the WBC carryover into packed platelets. An alternative centrifugation protocol to minimize WBC carryover is suggested. Whole blood is centrifuged at 2500 rpm for 1.5 minutes (rather than 4 min) and allowed to stop with no braking. This procedure adds some 3 minutes to the total centrifugation time, but the relative integral of this centrifugation program is approximately 50 percent smaller than that of the normally employed centrifugation protocol (with braking). It was observed that the WBC content throughout the expressed PRP, or in the entire PC, is reduced by about 75 percent. These results show that an effective method of significantly decreasing the WBC content of platelet units is simply to prepare PRP with reduced centrifugation time and with the braking programs disengaged.
白细胞（WBCs）是血小板浓缩物（PCs）的一种重要污染物。目前正在开发各种技术，包括单采和过滤，以尽量减少白细胞混入血小板中。目标是将每个血小板单位中的白细胞污染减少到10⁸以下。作为血库操作质量控制监测的一部分，已对制备富血小板血浆（PRP）时采用的离心方案对PCs中白细胞含量的影响进行了评估。白细胞含量在整个PRP体积以及PC中都有体现，反映了制动程度。例如，将全血以2500转/分钟的速度离心4分钟，分离出红细胞压积（RBCs）和PRP后，制动引起的混合会增加所提取PRP中的白细胞含量。所用离心机制动速率的变化也与白细胞混入压积血小板的情况相关。有人提出了一种可尽量减少白细胞混入的替代离心方案。将全血以2500转/分钟的速度离心1.5分钟（而非4分钟），然后在无制动的情况下让离心机停止。此程序使总离心时间增加了约3分钟，但该离心程序的相对积分比正常使用的离心方案（带制动）小约50%。据观察，所提取PRP或整个PC中的白细胞含量降低了约75%。这些结果表明，显著降低血小板单位中白细胞含量的一种有效方法就是在制备PRP时减少离心时间并取消制动程序。
