Kaufman J, Spinelli S L, Schultz E, Blumberg N, Phipps R P
Laboratory of Molecular Neuroocology, The Rockefeller University, New York, NY, USA.
J Thromb Haemost. 2007 Apr;5(4):788-96. doi: 10.1111/j.1538-7836.2007.02412.x.
Millions of platelet transfusions are given each year. Transfusion reactions occur in as many as 30% of patients receiving unmodified platelet transfusions. The cause of some transfusion reactions remains unclear. The current paradigm suggests that platelet concentrates (PC) contain proinflammatory mediators that are released by white blood cells during collection, processing and storage. CD154 (CD40 ligand, CD40L) is a potent inflammatory mediator, normally sequestered inside the resting platelet, that is known to translocate to the platelet membrane and be shed into plasma in response to agonist activation. We hypothesized that platelet-soluble CD154 (sCD154) is 'spontaneously' released by transfused platelets and plays a major role in transfusion reactions.
To determine the time course and biological properties of CD154 translocation and release during collection and storage of platelets for transfusion.
We measured surface and sCD154 in platelets prepared by the platelet-rich plasma method or apheresis by fluorescence-activated cell sorting and enzyme-linked immunosorbent assay, respectively. The specific biological activity of platelet sCD154 was assayed by stimulation of the CD154/CD40 pathway in known CD40-positive cells with PC-derived supernatants.
We demonstrate that PCs prepared for transfusion have high levels of membrane-bound CD154 and sCD154, with maximum levels being seen 72 h after platelet collection. Importantly, we show that platelet-derived sCD154 potently stimulates CD40-positive cells. We propose that platelet-derived CD154 is a key 'cytokine' responsible for adverse reactions associated with platelet transfusions. Improved methods of platelet collection and/or storage, which limit CD154 expression, could reduce the risks of transfusion reaction.
每年有数百万次血小板输注。在接受未处理血小板输注的患者中，高达30%会发生输血反应。一些输血反应的原因尚不清楚。目前的范例表明，血小板浓缩物（PC）含有在采集、处理和储存过程中由白细胞释放的促炎介质。CD154（CD40配体，CD40L）是一种强效炎症介质，通常被隔离在静息血小板内，已知其会因激动剂激活而转移至血小板膜并释放到血浆中。我们假设血小板可溶性CD154（sCD154）由输注的血小板“自发”释放，并在输血反应中起主要作用。
确定用于输血的血小板在采集和储存过程中CD154转移和释放的时间进程及生物学特性。
我们分别通过荧光激活细胞分选和酶联免疫吸附测定法，测量了通过富血小板血浆法或单采制备的血小板中的表面CD154和sCD154。通过用PC衍生的上清液刺激已知CD40阳性细胞中的CD154/CD40途径，测定血小板sCD154的特定生物学活性。
我们证明，用于输血制备的PC具有高水平的膜结合CD154和sCD154，在血小板采集后72小时达到最高水平。重要的是，我们表明血小板衍生的sCD154能有效刺激CD40阳性细胞。我们提出，血小板衍生的CD154是导致与血小板输注相关不良反应的关键“细胞因子”。改进血小板采集和/或储存方法以限制CD154表达，可降低输血反应风险。
