title: [Attempts for aspirin monitoring with a new assay system, Ultegra Rapid Platelet Function Assay (RPFA), based on turbidimetric platelet agglutination of whole blood samples].
abstract: Platelet aggregation measured by the optical density method has been applied for the assessment of platelet functions. However, as the method has to use platelet-rich plasma, it requires centrifugation of blood samples, which takes a considerable period of time. Using whole blood as samples has advantage because there is no pre-treatment of samples before measurement of platelet functions. Additionally, it would be desirable to have a bedside assay that reflects hyper-function of platelets and can monitor inhibitory effects of anti-platelet drugs. Rapid Platelet Function Assay (RPFA) is a qualitative test to aid the detection of platelet dysfunction due to anti-platelet drug ingestion, which uses citrated whole blood for sample in point of care or laboratory settings. The RPFA is a turbidimetric analysis, based on an optical detection system which measures platelet agglutination as an increase in light transmission. The aim of this study is to assess the accuracy and reproducibility of RPFA and to determine whether RPFA can monitor the effects of anti-platelet drugs. During the first 30 minutes after blood collection, Aspirin Reaction Units (ARU) determined with RPFA gradually increased, and reached its plateau after 30 minutes. The ARU values remained almost constant thereafter until 6 hours after blood collection (Fig. 3). These findings suggest that platelet function is unstable immediately after blood collection. Therefore, in this study ARU measurement was performed 60 minutes after blood collection. The reproducibility of ARU is very good both before and after aspirin intake. Seven days after daily uptake aspirin, ARU was decreased as compared with the control (440.8 +/- 39.4 vs. 663.4 +/- 2.4 ARU). RPFA measurement provides rapid information on platelet function that mirrors turbidimetric platelet agglutination and reflects COX1-depedent platelet activity.
authors.affiliation: Department of Clinical and Laboratory Medicine, School of Medicine, University of Yamanashi, Chuo.
authors.forename: Kaneo
authors.initials: K
authors.lastname: Satoh
authors.forename: Yukio
authors.initials: Y
authors.lastname: Ozaki
mesh_terms: D001241:Aspirin / Q000494:pharmacology*; D016903:Drug Monitoring / Q000295:instrumentation*; D006801:Humans; D008297:Male; D009391:Nephelometry and Turbidimetry / Q000295:instrumentation*; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*
chemical_list: D010975:Platelet Aggregation Inhibitors; D001241:Aspirin