Yılmaz Soner, Çetinkaya Rıza Aytaç, Eker İbrahim, Ünlü Aytekin, Uyanık Metin, Tapan Serkan, Pekoğlu Ahmet, Pekel Aysel, Erkmen Birgül, Muşabak Uğur, Yılmaz Sebahattin, Avcı İsmail Yaşar, Avcu Ferit, Kürekçi Emin, Eyigün Can Polat
Gülhane Military Medical Academy, Blood Training Center and Blood Bank, Ankara, Turkey. Phone : +90 312 304 49 02 E-mail :
Turk J Haematol. 2016 Mar 5;33(1):28-33. doi: 10.4274/tjh.2014.0181. Epub 2015 Apr 27.
Transfusion of platelet suspensions is an essential part of patient care for certain clinical indications. In this pioneering study in Turkey, we aimed to assess the in vitro hemostatic functions of platelets after cryopreservation.
Seven units of platelet concentrates were obtained by apheresis. Each apheresis platelet concentrate (APC) was divided into 2 equal volumes and frozen with 6% dimethyl sulfoxide (DMSO). The 14 frozen units of APCs were kept at -80 °C for 1 day. APCs were thawed at 37 °C and diluted either with autologous plasma or 0.9% NaCl. The volume and residual numbers of leukocytes and platelets were tested in both before-freezing and post-thawing periods. Aggregation and thrombin generation tests were used to analyze the in vitro hemostatic functions of platelets. Flow-cytometric analysis was used to assess the presence of frozen treated platelets and their viability.
The residual number of leukocytes in both dilution groups was <1x106. The mean platelet recovery rate in the plasma-diluted group (88.1±9.5%) was higher than that in the 0.9% NaCl-diluted group (63±10%). These results were compatible with the European Directorate for the Quality of Medicines quality criteria. Expectedly, there was no aggregation response to platelet aggregation test. The mean thrombin generation potential of post-thaw APCs was higher in the plasma-diluted group (2411 nmol/L per minute) when compared to both the 0.9% NaCl-diluted group (1913 nmol/L per minute) and the before-freezing period (1681 nmol/L per minute). The flow-cytometric analysis results for the viability of APCs after cryopreservation were 94.9% and 96.6% in the plasma and 0.9% NaCl groups, respectively.
Cryopreservation of platelets with 6% DMSO and storage at -80 °C increases their shelf life from 7 days to 2 years. Besides the increase in hemostatic functions of platelets, the cryopreservation process also does not affect their viability rates.
对于某些临床指征，输注血小板悬液是患者护理的重要组成部分。在土耳其的这项开创性研究中，我们旨在评估血小板冷冻保存后的体外止血功能。
通过单采获得7单位血小板浓缩物。将每份单采血小板浓缩物（APC）分成2等份，并用6%二甲基亚砜（DMSO）冷冻。14个冷冻的APC单位在-80°C保存1天。APC在37°C解冻，并用自体血浆或0.9%氯化钠稀释。在冷冻前和解冻后时期均检测白细胞和血小板的体积及残留数量。采用聚集试验和凝血酶生成试验分析血小板的体外止血功能。采用流式细胞术分析评估冷冻处理血小板的存在情况及其活力。
两个稀释组中的白细胞残留数量均<1×10⁶。血浆稀释组的平均血小板回收率（88.1±9.5%）高于0.9%氯化钠稀释组（63±10%）。这些结果符合欧洲药品质量管理局的质量标准。不出所料，血小板聚集试验无聚集反应。与0.9%氯化钠稀释组（每分钟1913 nmol/L）和冷冻前时期（每分钟1681 nmol/L）相比，血浆稀释组解冻后APC的平均凝血酶生成潜力更高（每分钟2411 nmol/L）。冷冻保存后APC活力的流式细胞术分析结果在血浆组和0.9%氯化钠组分别为94.9%和96.6%。
用6%DMSO冷冻保存血小板并在-80°C储存可将其保质期从7天延长至2年。除了血小板止血功能增强外，冷冻保存过程也不影响其活力率。
