Research and Development Unit in Region Östergötland and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden.
Department of Laboratory Medicine, Karolinska Institutet, Solna, Sweden.
Transfusion. 2021 Feb;61(2):546-556. doi: 10.1111/trf.16227. Epub 2020 Dec 21.
Cryopreserved platelets show a reduced recovery and viability after freezing and thawing including several ultrastructural and phenotypic deteriorations compared with liquid-stored platelets. It is suggested that using Controlled-Rate Freezing (CRF) can reduce variability and optimize the functionality profile for cells. The objective of the study is to compare cellular, metabolic, phenotypic and functional effects on platelets after cryopreservation using different freezing rate protocols.
To evaluate the possible effects of different freezing rate protocols a two-experimental study comparing diverse combinations was tested with a pool and split design. Uncontrolled freezing of platelets in materials with different thermal conductivity (metal vs cardboard) was evaluated in experiment 1. Experiment 2 evaluated uncontrolled vs a controlled-rate freezing protocol in metal boxes. All variables were assessed pre and post cryopreservation.
Directly after thawing, no major differences in platelet recovery, LDH, ATP, Δψ, CD62P, CD42b, platelet endothelial cell adhesion molecule and sCD40L were seen between units frozen with different thermal conductivity for temperature. In contrast, we observed signs of increased activation after freezing using the CRF protocol, reflected by increased cell surface expression of CD62P, PAC-1 binding and increased concentration of LDH. Agonist induced expression of a conformational epitope on the GPIIb/IIIa complex and contribution to blood coagulation in an experimental rotational thromboelastometry setup were not statistically different between the groups.
The use of a uncontrolled freezing rate protocol is feasible, creating a platelet product comparable to using a controlled rate freezing equipment during cryopreservation of platelets.
与液态储存的血小板相比，冷冻和解冻后的冷冻血小板回收率和活力降低，包括几种超微结构和表型恶化。有人认为，使用控速冷冻（CRF）可以减少变异性并优化细胞的功能谱。本研究的目的是比较使用不同冷冻速率方案冷冻保存后对血小板的细胞、代谢、表型和功能影响。
为了评估不同冷冻速率方案的可能影响，采用池和分割设计对不同组合进行了两项实验研究。在实验 1 中，评估了在具有不同热导率（金属与纸板）的材料中对血小板进行不受控制的冷冻的效果。实验 2 评估了金属盒中不受控制与控速冷冻方案的效果。所有变量均在冷冻前后进行评估。
直接解冻后，在温度方面，使用不同热导率的材料冷冻的血小板中，血小板回收率、LDH、ATP、Δψ、CD62P、CD42b、血小板内皮细胞黏附分子和 sCD40L 没有明显差异。相比之下，我们观察到使用 CRF 方案冷冻后血小板激活增加的迹象，表现为细胞表面 CD62P、PAC-1 结合和 LDH 浓度增加。在实验旋转血栓弹性测定装置中，激动剂诱导的 GPIIb/IIIa 复合物构象表位表达和对血液凝固的贡献在各组之间没有统计学差异。
使用非控速冷冻方案是可行的，在冷冻保存血小板时，可获得与使用控速冷冻设备相当的血小板产品。
