Multiple electrode aggregometry:A new device to ...

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Summary. Several methods are used to analyse platelet function in whole blood. A new device to measure whole blood platelet aggre- gation has been ...
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Platelets and Blood Cells

Multiple electrode aggregometry: A new device to measure platelet aggregation in whole blood Orsolya Tóth1,2, Andreas Calatzis3, Sandra Penz1, Hajna Losonczy2, Wolfgang Siess1 1

Institute for Prevention of Cardiovascular Diseases, University of Munich, Munich, Germany; 21stDepartment of Medicine, University of Pécs, Pécs, Hungary; 3Department of Transfusion Medicine and Hemostaseology, University of Munich, Munich, Germany

Summary Several methods are used to analyse platelet function in whole blood. A new device to measure whole blood platelet aggregation has been developed, called multiple electrode platelet aggregometry (MEA).Our aim was to evaluate MEA in comparison with the single platelet counting (SPC) method for the measurement of platelet aggregation and platelet inhibition by aspirin or apyrase in diluted whole blood. Platelet aggregation induced by different concentrations of ADP, collagen and TRAP-6 and platelet inhibition by apyrase or aspirin were determined in citrateor hirudin-anticoagulated blood by MEA and SPC. MEA indicated that spontaneous platelet aggregation was lower, and stimulated platelet aggregation was higher in hirudin- than citrate-anticoagulated blood.In hirudin-anticoagulated,but not citrate-anticoagulated blood, spontaneous platelet aggregation Keywords Anticoagulation, multiple electrode aggregometry, platelet aggregation, single platelet counting

Introduction The study of the role of platelets in the pathogenesis of ischemic vascular diseases and the monitoring of anti-platelet drugs in patients with cardio- and cerebrovascular diseases requires reliable platelet-function tests. Several techniques are in use to measure platelet aggregation. The most commonly used method is lighttransmission aggregometry (“Born” aggregometry) employing citrated or heparinised platelet-rich plasma (PRP) (1). Disadvantages of this technique include the need of centrifugation to separate other blood cells from platelets, which are also known to influence platelet function (2, 3). Besides, PRP does not contain all blood platelets. The platelet recovery rate is only 61% to 90% of total, depending on the separation methods used (4–6). This usually leads to the loss of giant platelets which may be both hypo- and hyperactive (7). All these factors may artificially alter

measured by MEA was inhibited by apyrase. For MEA compared with SPC the dose response-curves of agonist-induced platelet aggregation in citrate- and hirudin-blood showed similar EC50 values for TRAP, and higher EC50 values for ADP (non-significant) and collagen (p