Kovács Emese G, Katona Éva, Bereczky Zsuzsanna, Homoródi Nóra, Balogh László, Tóth Eszter, Péterfy Hajna, Kiss Róbert G, Édes István, Muszbek László
Clinical Research Center, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary.
Institute of Cardiology, University of Debrecen, Medical and Health Science Center, Debrecen, Hungary.
Thromb Res. 2014 May;133(5):811-6. doi: 10.1016/j.thromres.2013.10.008. Epub 2013 Oct 16.
Aspirin, a commonly used antiplatelet agent, blocks platelet thromboxane A₂ (TXA₂) formation from arachidonic acid (AA) by acetylating platelet cyclooxygenase-1 (COX-1). Laboratory methods currently used to detect this antiplatelet effect of aspirin provide variable results. We have reported three methods that assess platelet COX-1 acetylation (inactivation) by aspirin and its direct consequences. The first and second assays use monoclonal anti-human-COX-1 antibodies that only detect acetylated (inactivated) COX-1 and active (non-acetylated) COX-1, respectively. The third method measures platelet production of TXB₂ (the stable metabolite of TXA₂) in vitro in response to AA. We compared the results of these three reference methods with other routinely used methods for assessing the functional consequences aspirin treatment.
108 healthy volunteers were treated with low-dose aspirin for 7 days. On day 7 following aspirin treatment COX-1 in the platelets was fully acetylated whereas only non-acetylated COX-1 was present in the day 0 platelets. Further, TXB2 production by day 7 platelets was completely blocked. The following tests were performed on the samples obtained from study participants before and after seven days of aspirin treatment: PFA-100 closure time with collagen/epinephrine cartridge, VerifyNow (VN) Aspirin Assay, platelet aggregation and ATP secretion using AA, ADP, epinephrine and collagen as agonists.
Comparing the pre-treatment and day 7 values, methods that use AA as platelet agonist (AA-induced platelet aggregation/secretion and VN Aspirin Assay) showed high discriminative power. In contrast, results of the other tests showed considerable overlap between day 7 and day 0 values.
Only assays that clearly distinguish between acetylated and non-acetylated platelet COX-1 are useful for establishing the antiplatelet effect of aspirin. The other tests are not suitable for this purpose.
阿司匹林是一种常用的抗血小板药物，通过使血小板环氧化酶-1（COX-1）乙酰化，阻断血小板从花生四烯酸（AA）生成血栓素A₂（TXA₂）。目前用于检测阿司匹林这种抗血小板作用的实验室方法结果不一。我们报道了三种评估阿司匹林对血小板COX-1乙酰化（失活）及其直接后果的方法。第一种和第二种检测方法分别使用仅能检测乙酰化（失活）COX-1和活性（非乙酰化）COX-1的单克隆抗人COX-1抗体。第三种方法在体外测量血小板对AA反应时TXB₂（TXA₂的稳定代谢产物）的生成量。我们将这三种参考方法的结果与其他常规用于评估阿司匹林治疗功能后果的方法进行了比较。
108名健康志愿者接受低剂量阿司匹林治疗7天。在阿司匹林治疗后的第7天，血小板中的COX-1完全乙酰化，而在第0天的血小板中仅存在非乙酰化的COX-1。此外，第7天血小板的TXB2生成被完全阻断。对研究参与者在阿司匹林治疗7天前后采集的样本进行以下检测：使用胶原/肾上腺素检测卡的PFA-100封闭时间、VerifyNow（VN）阿司匹林检测、使用AA、ADP、肾上腺素和胶原作为激动剂的血小板聚集和ATP分泌。
比较治疗前和第7天的值，使用AA作为血小板激动剂的方法（AA诱导的血小板聚集/分泌和VN阿司匹林检测）显示出高辨别力。相比之下，其他检测结果显示第7天和第0天的值有相当大的重叠。
只有能明确区分乙酰化和非乙酰化血小板COX-1的检测方法才有助于确定阿司匹林的抗血小板作用。其他检测方法不适合此目的。
