Bikker Angela, Bouman Esther, Sebastian Silvie, Korporaal Suzanne J A, Urbanus Rolf T, Fijnheer Rob, Boven Leonie A, Roest Mark
Department of Clinical Chemistry, Meander Medical Center, Amersfoort.
Department of Clinical Chemistry and Haematology, University Medical Center, Utrecht, the Netherlands.
Transfusion. 2016 May;56(5):1030-7. doi: 10.1111/trf.13544. Epub 2016 Mar 2.
Platelet (PLT) concentrates are prophylactically given to prevent major bleeding complications. The corrected count increment (CCI) is currently the only tool to monitor PLT transfusion efficacy. PLT function tests cannot be performed in patients with thrombocytopenia. Therefore, an optimized agonist-induced assay was used to determine PLT function, in patients with severe thrombocytopenia before and after transfusion.
PLT reactivity toward adenosine diphosphate (ADP), thrombin receptor-activating peptide SFLLRN (TRAP), and convulxin (CVX) was assessed by flow cytometry. P-selectin expression was measured on PLTs from 11 patients with thrombocytopenia before and 1 hour after transfusion, on stored PLTs, and on stored PLTs incubated for 1 hour in whole blood from patients ex vivo.
The mean (±SEM) CCI after 1 hour was 11.4 (±1.5). After transfusion, maximal agonist-induced PLT P-selectin expression was on average 29% higher for ADP (p = 0.02), 25% higher for TRAP (p = 0.007), and 24% higher for CVX (p = 0.0008). ADP-induced reactivity of stored PLTs increased with 46% after ex vivo incubation (p = 0.007). These PLTs also showed an overall higher P-selectin expression compared to PLTs 1 hour after transfusion (p = 0.005). After normalization for this background expression, a similar responsiveness was observed.
Our study shows recovery of PLT function after transfusion in patients with thrombocytopenia. The majority of functional PLTs measured after transfusion most likely represents stored transfused PLTs that regained functionality in vivo. The difference in baseline P-selectin expression in vivo versus ex vivo suggests a rapid clearance from circulation of PLTs with increased P-selectin expression.
预防性输注血小板浓缩物以预防严重出血并发症。校正计数增加值（CCI）是目前监测血小板输注疗效的唯一工具。血小板减少症患者无法进行血小板功能测试。因此，我们采用优化的激动剂诱导试验来测定严重血小板减少症患者输血前后的血小板功能。
通过流式细胞术评估血小板对二磷酸腺苷（ADP）、凝血酶受体激活肽SFLLRN（TRAP）和convulxin（CVX）的反应性。在11例血小板减少症患者输血前和输血后1小时的血小板上、储存的血小板上以及离体在患者全血中孵育1小时的储存血小板上测量P-选择素表达。
1小时后的平均（±标准误）CCI为11.4（±1.5）。输血后，激动剂诱导的血小板P-选择素最大表达平均而言，ADP诱导的高29%（p = 0.02），TRAP诱导的高25%（p = 0.007），CVX诱导的高24%（p = 0.0008）。离体孵育后，储存血小板的ADP诱导反应性增加了46%（p = 0.007）。与输血后1小时的血小板相比，这些血小板还显示出总体更高的P-选择素表达（p = 0.005）。对此背景表达进行归一化后，观察到类似的反应性。
我们的研究表明血小板减少症患者输血后血小板功能恢复。输血后测量的大多数功能性血小板很可能代表储存的输注血小板，它们在体内恢复了功能。体内与离体基线P-选择素表达的差异表明，P-选择素表达增加的血小板从循环中快速清除。
