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Extracellular matrix metalloproteinase inducer (EMMPRIN; CD147), which binds to the platelet-specific collagen receptor glycoprotein (GP) VI, is expressed in a range of cell types including platelets and leukocytes, and has been implicated in neoplastic disease and atherosclerotic coronary disease. Both CD147 and GPVI can be shed from cell membranes and detected in plasma. However, while the relationship between soluble CD147 (sCD147), soluble GPVI (sGPVI) and standard markers of platelet activation has received little attention, such analysis may help reveal pathways mediating release of sCD147. We investigated the relationship between sCD147 and platelet markers including sGPVI, soluble and platelet-bound CD62P (P-selectin), active αIIbβ3 (assessed by PAC-1 binding) and platelet CD147 in 25 patients with stable angina pectoris (SAP), 13 patients with no coronary artery disease (CAD) and 10 healthy donors. Plasma levels of sCD147 significantly correlated with sGPVI ( r = 0.46, p = .004), but did not correlate with any other platelet markers examined. Linear regression analysis identified that sCD147 levels could be predicted by sGPVI levels ( β = .445, p = 0.003) and age ( β = 0.304, p = 0.038), but were independent of potential clinical confounders such as CAD, diabetes and medication usage. As sCD147 strongly correlates with platelet-specific sGPVI, a common platelet source and/or mechanism of release may contribute to sCD147 levels in vivo. [ABSTRACT FROM AUTHOR]

Essentials Procoagulant platelets can be detected using GSAO in human whole blood. Stable coronary artery disease is associated with a heightened procoagulant platelet response. Agonist-induced procoagulant platelet response is not inhibited by aspirin alone. Collagen plus thrombin induced procoagulant platelet response is partially resistant to clopidogrel., Summary: Background Procoagulant platelets are a subset of highly activated platelets with a critical role in thrombin generation. Evaluation of their clinical utility in thrombotic disorders, such as coronary artery disease (CAD), has been thwarted by the lack of a sensitive and specific whole blood assay. Objectives We developed a novel assay, utilizing the cell death marker, GSAO [(4-(N-(S-glutathionylacetyl)amino)phenylarsonous acid], and the platelet activation marker, P-selectin, to identify procoagulant platelets in whole blood by flow cytometry. Patients/Methods Using this assay, we characterized the procoagulant platelet population in healthy controls and a cohort of patients undergoing elective coronary angiography. Results In patients with CAD, compared with patients without CAD, there was a heightened procoagulant platelet response to thrombin (25.2% vs. 12.2%), adenosine diphosphate (ADP) (7.8% vs. 2.7%) and thrombin plus collagen (27.2% vs. 18.3%). The heightened procoagulant platelet potential in CAD patients was not associated with other markers of platelet function, including aggregation, dense granule release and activation of α 2b β 3 integrin. Although dual antiplatelet therapy (DAPT) was associated with partial suppression of procoagulant platelets, this inhibitory effect on a patient level could not be predicted by aggregation response to ADP and was not fully suppressed by clopidogrel. Conclusions We report for the first time that procoagulant platelets can be efficiently detected in a few microliters of whole blood using the cell death marker, GSAO, and the platelet activation marker, P-selectin. A heightened procoagulant platelet response may provide insight into the thrombotic risk of CAD and help identify a novel target for antiplatelet therapies in CAD., (© 2018 The Authors. Journal of Thrombosis and Haemostasis published by Wiley Periodicals, Inc. on behalf of International Society on Thrombosis and Haemostasis.)