title: Platelet aggregation monitoring with a newly developed quartz crystal microbalance system as an alternative to optical platelet aggregometry.
abstract: The objective of this study was to establish a new test system for the monitoring of platelet aggregation during extracorporeal circulation (ECC) procedures. Even though extensive progress has been made in improving the haemocompatibility of extracorporeal circulation devices, activation of blood coagulation, blood platelets and inflammatory responses are still undesired outcomes of cardiopulmonary bypass. This study deals with an approach towards a platelet aggregation measuring system using a newly developed quartz crystal microbalance (QCM) system. Since QCM is a rarely used technique in the field of blood analytics, the challenge was to transfer the well established methods of aggregometry to the new test system. In a QCM system, either bare gold or fibrinogen-coated sensors were incubated with ADP or arachidonic acid (AA) stimulated platelet rich plasma. For negative controls the GPIIb/IIIa inhibitory antibody abciximab (Reopro®) was used as an inhibitor of platelet aggregation. During incubation, the frequency shifts of the sensors were recorded. The results gained from the QCM system were compared to results gained by optical platelet aggregometry (born aggregometry). For additional visualization of platelet adhesion to the sensor surfaces, fluorescent microscopy and scanning electron microscopy were used. The QCM sensor was able to detect platelet aggregation in both uncoated and fibrinogen coated sensors. The measuring curves of aggregation measurements and controls were clearly distinguishable from each other in terms of frequency shifts and kinetics. For aggregation measurements and inhibited controls the therapeutic diagnosis of platelet function is identical between aggregometer and QCM data. In future, QCM based measuring devices may become an alternative to established point of care methods for rapid bedside testing of platelet aggregation.
authors.affiliation: Children's University Hospital, Div. Congenital & Pediatric Cardiac Surgery, Clinical Research Laboratory, Tuebingen University, Calwerstr. 7/1, 72076 Tuebingen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Sinn
authors.forename: Lothar
authors.initials: L
authors.lastname: Müller
authors.forename: Hartmut
authors.initials: H
authors.lastname: Drechsel
authors.forename: Michael
authors.initials: M
authors.lastname: Wandel
authors.forename: Hinnak
authors.initials: H
authors.lastname: Northoff
authors.forename: Gerhard
authors.initials: G
authors.lastname: Ziemer
authors.forename: Hans P
authors.initials: HP
authors.lastname: Wendel
authors.forename: Frank K
authors.initials: FK
authors.lastname: Gehring
mesh_terms: D000077284:Abciximab; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D005340:Fibrinogen / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D006801:Humans; D007140:Immunoglobulin Fab Fragments / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D010974:Platelet Aggregation / Q000187:drug effects; D010976:Platelet Count; D010979:Platelet Function Tests; D058525:Quartz Crystal Microbalance Techniques / Q000295:instrumentation* / Q000379:methods*; D012016:Reference Values; D012680:Sensitivity and Specificity
chemical_list: D000911:Antibodies, Monoclonal; D007140:Immunoglobulin Fab Fragments; D006046:Gold; D005340:Fibrinogen; D000077284:Abciximab