Thrombus formation with rehydrated, lyophilized platelets.
Thrombus formation with rehydrated, lyophilized platelets.
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DOI：
10.1080/1024533021000047954
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发表时间：
2002-12-01
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影响因子：
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通讯作者：
Read, Marjorie S
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文献类型：
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作者：
Fischer, Thomas H;Merricks, Elizabeth P;Read, Marjorie S
储存的人血小板经常用于出血紧急情况，但由于储存损伤而控制出血的直接效用有限，并且经常被微生物污染。经过多聚甲醛处理的冻干再水合 (RL) 血小板是无菌的，且保质期较长（数年），其开发改善了储存血小板的功效和无菌问题。 RL 血小板已被证明在体外具有新鲜血小板的许多天然功能，并在失血性休克和体外循环诱导的血小板功能障碍的大型动物模型中介导体内止血。为了进一步评估该输血产品的功能特性，我们研究了RL血小板在血栓形成和溶解三个方面的作用。首先，研究了 RL 血小板和纤维蛋白原之间的相互作用。用单克隆抗体10E-5检测，RL和新鲜血小板上未连接的GPIIb-IIIa的表面密度分别为每个细胞30000和70000个分子。制备 RL 血小板时的冷冻、冻干和再水化步骤导致每个细胞表面呈现 120000 个来自 α 颗粒来源的纤维蛋白原分子。 ADP 激活后，RL 血小板以剂量依赖性方式结合外源 125I 标记的纤维蛋白原，其亲和力与新鲜血小板相似，并被 RGD 肽抑制。 125I 标记的纤维蛋白原分别与 RL 和新鲜血小板结合，每个细胞在 14000 和 32000 个分子时达到饱和。扫描电子显微镜超微结构分析表明，纤维蛋白链以正常方式与 RL 血小板表面相互作用。第二组研究调查了 RL 血小板以激活依赖性方式催化和放大凝块形成过程的能力。我们发现，RL 血小板在凝块中的纤维蛋白中经历脱颗粒，并作为血栓形成表面，用于产生活化的凝血因子和纤维蛋白。最后一组研究是为了研究含有 RL 血小板的凝块的纤维蛋白。 RL 血小板凝块在组织纤溶酶原激活剂存在下裂解，其时间过程与不含血小板的凝块相似，并且裂解发生得比新鲜血小板包含在纤维蛋白团中时更快。这三项研究的结果表明，RL 血小板能够介导血栓形成并且不会抑制溶解。我们的结果有助于解释 RL 血小板如何恢复体内止血，并表明这些细胞可能是输血医学中新鲜储存血小板的可行替代品。
Stored human platelets are frequently used in hemorrhagic emergencies, but have limited immediate utility for controlling bleeding due to storage lesion and are frequently contaminated with microorganisms. The development of paraformaldehyde-treated, lyophilized and rehydrated (RL) platelets, which are sterile and have a prolonged shelf life (years), ameliorate the efficacy and sterility problems with stored platelets. RL platelets have been shown to have many native functions of fresh platelets in vitro and to mediate hemostasis in vivo in large animal models of hemorrhagic shock and cardiopulmonary bypass induced platelet dysfunction. To further evaluate the functional properties of this transfusion product, we studied the role of RL platelets in three aspects of thrombus formation and lysis. First, the interaction between RL platelets and fibrinogen was investigated. The surface density of unligated GPIIb-IIIa on RL and fresh platelets were, respectively 30000 and 70000 molecules per cell as detected with the monoclonal antibody 10E-5. Freezing, lyophilization and rehydration steps in the preparation of RL platelets resulted in the surface presentation of 120000 molecules of fibrinogen per cell from alpha granule sources. After ADP activation, RL platelets bound exogenous 125I-labeled fibrinogen in a dose-dependent manner with an affinity that is similar to that of fresh platelets and was inhibited by RGD peptides. 125I-Labeled fibrinogen binding to RL and fresh platelets, respectively, saturated at 14000 and 32000 molecules per cell. Scanning electron microscopic ultrastructural analysis showed that fibrin strands interacted with the surface of RL platelets in a normal manner. The second set of studies investigated the ability of RL platelets to catalyze and amplify the clot formation process in an activation-dependent manner. We showed that RL platelets undergo degranulation in fibrin in clots and functioned as thrombogenic surfaces for the generation of activated coagulation factors and fibrin generation. A final set of studies was performed to investigate fibrin of clots that contained RL platelets. RL platelet clots were lysed in the presence of tissue plasminogen activator with a similar time course as clots without platelets, and lysis occurred faster than when fresh platelets were included in the fibrin mass. The results of these three studies demonstrate that RL platelets are capable of mediating thrombus formation and do not inhibit lysis. Our results help explain how RL platelets restore hemostasis in vivo, and indicate that these cells might be a viable alternative to fresh stored platelets in transfusion medicine.