Veterinary Specialty Hospital, San Diego, California.
College of Veterinary Medicine, Western University of Health Sciences, Pomona, California.
J Vet Emerg Crit Care (San Antonio). 2021 Mar;31(2):221-230. doi: 10.1111/vec.13050. Epub 2021 Mar 10.
To characterize the size and procoagulant activity of extracellular vesicles (EV) that accumulate in canine packed red blood cells (pRBCs) over time and the effect of leukocyte reduction on these characteristics.
Prospective cohort study.
Private small animal specialty referral hospital and university research laboratories.
Ten healthy blood donor dogs.
Five pRBCs units were obtained according to standard protocols, and 5 were leukocyte-reduced prior to processing. Platelet-free supernatant from the pRBC units was collected on days 0, 10, 20, 32, and 42.
Nanoparticle tracking analysis was performed to determine the size and concentration of EVs. Thrombin generation associated with phosphatidylserine-positive EVs was determined using a capture assay. Factor Xa generation associated with phosphatidylserine-positive EVs and tissue factor-positive EVs was measured in a subset of EVs isolated by centrifugation of the supernatant at 20,000 × g. R package nparLD and the Mann-Whitney U-test were used to determine the effect of duration of storage and the effect of leukocyte reduction, respectively. Small (mean < 125 nm) procoagulant EVs accumulated over time, with significant increases occurring on or after day 20 in both non-leukocyte reduced and leukocyte-reduced units. The procoagulant activity of the EVs was due to phosphatidylserine, not tissue factor. Increases in EV concentration and procoagulant activity occurred earlier in non-leukocyte reduced units. Extracellular vesicle accumulation and procoagulant activity were not decreased at any individual time point by leukocyte reduction.
Further studies characterizing and determining the clinical relevance of small procoagulant EVs in pRBCs are warranted.
描述在时间推移过程中，在犬浓缩红细胞（pRBC）中积累的细胞外囊泡（EV）的大小和促凝活性，以及白细胞减少对这些特性的影响。
前瞻性队列研究。
私人小型动物专科转诊医院和大学研究实验室。
10 只健康献血犬。
根据标准方案获得 5 个 pRBC 单位，并在处理前对其中 5 个进行白细胞减少处理。从 pRBC 单位收集血小板无 EV 上清液，分别在第 0、10、20、32 和 42 天采集。
通过纳米颗粒跟踪分析确定 EV 的大小和浓度。使用捕获测定法确定与 PS 阳性 EV 相关的凝血酶生成。在通过 20,000×g 离心上清液分离的 EV 亚集中测量与 PS 阳性 EV 和组织因子阳性 EV 相关的因子 Xa 生成。使用 R 包 nparLD 和 Mann-Whitney U 检验分别确定储存时间的影响和白细胞减少的影响。小（平均值 < 125nm）促凝 EV 随时间积累，在非白细胞减少和白细胞减少的单位中，分别在第 20 天或之后出现显著增加。EV 的促凝活性归因于 PS，而不是组织因子。在非白细胞减少的单位中，EV 浓度和促凝活性的增加更早发生。在任何单个时间点，白细胞减少都不会降低 EV 的积累和促凝活性。
需要进一步研究 pRBC 中小促凝 EV 的特征和确定其临床相关性。
