Cardiff School of Sport and Health Sciences, Cardiff Metropolitan University, Cardiff, UK.
Component Development and Research Laboratory, Welsh Blood Service, Pontyclun, UK.
Transfus Med. 2023 Dec;33(6):467-477. doi: 10.1111/tme.12989. Epub 2023 Aug 8.
Platelet derived extracellular vesicles (EVs) display a pro-coagulant phenotype and are generated throughout platelet concentrate (PC) storage. Cold storage (CS) of PCs is thought to provide a superior haemostatic advantage over room temperature (RT) storage and could prolong the storage time. However, the effect of storage conditions on EV generation and PC function is unknown. We investigated EV production under CS and RT conditions and assessed whether these EVs exhibited a more pro-coagulant phenotype in model experiments.
Buffy-coat-derived PCs in a platelet additive solution (PAS) to plasma ratio of approximately 65:35 were stored at RT (22 ± 2°C) or CS (4 ± 2°C) for a prolonged storage duration of 20 days. Impedance aggregometry assessed platelet function. EVs were isolated throughout storage and quantified using nanoparticle tracking analysis. EVs were applied to a coagulation assay to assess the impact on fibrin clot formation and lysis.
CS produced significantly larger EVs from day 4 onwards. EV concentration was significantly increased in CS compared to RT from day 15. EVs, regardless of storage, significantly reduced time to clot formation and maximum optical density measured compared to the no EV control. Clot formation was proportionate to the number of EV applied but was not statistically different across storage conditions when corrected for EV number.
EVs in CS and RT units showed similar clot formation capacity. However, the higher number of larger EVs generated in CS compared to RT suggests PC units derived from CS conditions may overall exhibit a haemostatically superior capacity compared to RT storage.
血小板衍生的细胞外囊泡（EVs）表现出促凝表型，并在血小板浓缩物（PC）储存过程中产生。冷储存（CS）被认为比室温（RT）储存提供更好的止血优势，并可以延长储存时间。然而，储存条件对 EV 产生和 PC 功能的影响尚不清楚。我们研究了 CS 和 RT 条件下 EV 的产生，并评估了这些 EV 是否在模型实验中表现出更促凝的表型。
用血小板添加剂溶液（PAS）中的 Buffy 涂层制备 PC，血浆比约为 65:35，在 RT（22±2°C）或 CS（4±2°C）下储存长达 20 天的延长储存时间。阻抗聚集度评估血小板功能。在整个储存过程中分离 EV，并使用纳米颗粒跟踪分析进行定量。将 EV 应用于凝血测定，以评估其对纤维蛋白凝块形成和溶解的影响。
CS 从第 4 天开始产生明显更大的 EV。从第 15 天开始，CS 中的 EV 浓度明显高于 RT。与无 EV 对照相比，无论储存条件如何，EV 都显著缩短了凝块形成时间和最大光密度测量值。凝块形成与 EV 数量成正比，但在根据 EV 数量校正后，在储存条件之间没有统计学差异。
CS 和 RT 单位中的 EV 显示出相似的凝块形成能力。然而，与 RT 储存相比，CS 中产生的较大 EV 数量更多，这表明与 RT 储存相比，源自 CS 条件的 PC 单位总体上可能表现出更好的止血能力。
