Rudderow D, Soslau G
Department of Biochemistry, Allegheny University of the Health Sciences, Philadelphia, Pennsylvania 19102, USA.
Proc Soc Exp Biol Med. 1998 Feb;217(2):219-27. doi: 10.3181/00379727-217-44226.
The demand for stored platelet concentrates (PC) for therapeutic transfusions has been increasing for the past three decades. Loss of platelet functionality increases with the length of storage time due to a multitude of factors collectively referred to as a platelet storage lesion. As more of the causes of the storage lesion have been defined, storage conditions have improved along with the therapeutic value of the transfused platelet samples. This report addressed new aspects of the storage lesion correlated with the pH of the storage medium. Platelet function was evaluated as aggregation induced by the synergistic agonist pair, U46619 (TXA2 mimetic) plus epinephrine or the strong agonists SFLLRNP (a peptide thrombin receptor agonist) or thrombin each added alone. Stored PC were compared to freshly prepared platelets as platelet-rich plasma (PRP) or washed platelets re-suspended in hepes Tyrode's buffer. The pH of the storage plasma, was inversely proportional to the cell count with platelets stored for 6 days. Agonist-induced platelet aggregation was significantly impaired by storage for 6-7 days as PRP; however, upon washing, a significant level of activity was restored. Washed platelets more accurately reflect conditions of transfused platelets that may regain activity in vivo. There appeared to be two subpopulations of stored PRP samples--one that retained activity and one that lost virtually all activity with the agonists tested. However, the lack of response to agonist observed with one subpopulation was reversed to the same level obtained with the active subpopulation upon washing. The subpopulation of stored PRP samples that were inactive with U46619-plus-epinephrine did not correspond to the subpopulation of samples that were nonresponsive to SFLLRNP, indicating that loss of activity with selected samples was possibly receptor specific. Loss of agonist-induced aggregation with PRP samples did not correlate with storage pH; however, the level of aggregation with washed platelets correlated significantly with pH. Results implied that pH caused a permanent storage lesion that could only be detected with washed platelets. A partially reversible lesion was superimposed on the pH lesion and was only detectable with PRP samples. Results indicate that continued attention must be paid to regulate the pH of stored PC even in the second generation plastic bags.
在过去三十年中，用于治疗性输血的储存血小板浓缩物（PC）的需求一直在增加。由于多种因素共同导致的血小板储存损伤，血小板功能的丧失会随着储存时间的延长而增加。随着更多储存损伤原因的明确，储存条件以及输注的血小板样本的治疗价值都得到了改善。本报告探讨了与储存介质pH相关的储存损伤的新方面。通过协同激动剂对U46619（血栓素A2模拟物）加肾上腺素或单独添加的强激动剂SFLLRNP（一种肽凝血酶受体激动剂）或凝血酶诱导的聚集来评估血小板功能。将储存的PC与新鲜制备的血小板（作为富血小板血浆（PRP）或重悬于赫氏台氏缓冲液中的洗涤血小板）进行比较。储存血浆的pH与储存6天的血小板细胞计数成反比。作为PRP储存6 - 7天会显著损害激动剂诱导的血小板聚集；然而，洗涤后，会恢复显著水平的活性。洗涤后的血小板更准确地反映了输注的血小板在体内可能恢复活性的情况。储存的PRP样本似乎有两个亚群——一个保留活性，另一个对所测试的激动剂几乎失去所有活性。然而，在洗涤后，观察到的对激动剂无反应的一个亚群的情况恢复到了与活性亚群相同的水平。对U46619加肾上腺素无活性的储存PRP样本亚群与对SFLLRNP无反应的样本亚群不对应，表明所选样本的活性丧失可能是受体特异性的。PRP样本中激动剂诱导的聚集丧失与储存pH无关；然而，洗涤血小板的聚集水平与pH显著相关。结果表明，pH导致了一种只能通过洗涤血小板检测到的永久性储存损伤。一种部分可逆的损伤叠加在pH损伤上，并且只能通过PRP样本检测到。结果表明，即使在第二代塑料袋中，也必须持续关注调节储存PC的pH。
