Department of Medicine and Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA.
Transfusion. 2011 Dec;51(12):2690-4. doi: 10.1111/j.1537-2995.2011.03179.x. Epub 2011 Jun 3.
Coated platelets (PLTs), a subpopulation of PLTs observed upon dual agonist stimulation with collagen and thrombin, are known to retain several procoagulant α-granule proteins on their surface. By formation of a highly active membrane-bound prothrombinase complex, these PLTs represent an important step in the coagulation cascade as a consequence of their ability to generate thrombin at the site of vascular injury. Various clinical observations suggest that higher levels of coated PLTs are associated with thrombosis while a deficiency of coated PLTs results in a bleeding diathesis. Current quality control guidelines for in vitro PLT storage measure PLT viability but no routine evaluation of the hemostatic function of stored PLTs and particularly no estimation of coated PLT potential is performed. Our primary objective was to evaluate if the process of apheresis and storage of PLT units alters the levels of coated PLTs. In addition, we sought to determine how transfusion of stored PLTs into patients with thrombocytopenia affects the patient's coated PLT levels.
Coated PLT levels were analyzed in 13 voluntary PLT donors before donation, in the fresh apheresis product (Trima, CaridianBCT) and in the stored apheresis product just before transfusion. In addition, 10 patients with thrombocytopenia were analyzed for coated PLTs before and after transfusion of a stored PLT product.
Coated PLT levels were significantly decreased after the process of apheresis (17% relative decline; p < 0.01) and with prolonged storage (1 to 5 days; 53% relative decline; p < 0.001). Transfusion of stored PLT units did not result in significant increment of coated PLT levels in patients with thrombocytopenia as expected considering the low level of coated PLTs in stored PLT units. Furthermore, there was no suggestion of regeneration of coated PLT potential upon reinfusion.
Isolation and storage of apheresis PLTs by standard blood bank procedures results in a significant decline in coated PLT potential. Reinfusion of stored apheresis PLTs into patients with thrombocytopenia resulted in a predictable change in coated PLT potential with no suggestion of regeneration of lost coated PLT potential.
在胶原和凝血酶双重激动剂刺激下观察到的血小板（PLT）亚群，即涂层血小板（coated PLTs），已知在其表面保留了几种促凝α-颗粒蛋白。由于其在血管损伤部位生成凝血酶的能力，这些 PLT 通过形成高度活跃的膜结合凝血酶原酶复合物，代表了凝血级联中的一个重要步骤。各种临床观察表明，涂层 PLT 水平较高与血栓形成有关，而涂层 PLT 缺乏则导致出血倾向。目前用于体外 PLT 储存的质量控制指南测量 PLT 活力，但没有对储存 PLT 的止血功能进行常规评估，特别是没有估计涂层 PLT 的潜力。我们的主要目标是评估体外分离和储存 PLT 单位的过程是否改变了涂层 PLT 的水平。此外，我们还试图确定输注储存的 PLT 对血小板减少症患者的患者涂层 PLT 水平的影响。
在捐赠前、新鲜的（Trima，CaridianBCT）和储存前，分析了 13 名自愿 PLT 供体的涂层 PLT 水平。此外，还分析了 10 名血小板减少症患者输注储存的 PLT 产品前后的涂层 PLT。
体外分离后涂层 PLT 水平显著下降（相对下降 17%；p<0.01），随着储存时间延长（1 至 5 天；相对下降 53%；p<0.001）。输注储存的 PLT 单位并未导致血小板减少症患者的涂层 PLT 水平显著升高，这考虑到储存的 PLT 单位中的涂层 PLT 水平较低。此外，在重新输注时，没有提示涂层 PLT 潜力的再生。
通过标准血库程序分离和储存 PLT 会导致涂层 PLT 潜力显著下降。输注储存的 PLT 单位到血小板减少症患者中导致涂层 PLT 潜力发生可预测的变化，没有提示失去的涂层 PLT 潜力的再生。
