Are Soluble and Platelet Surface P-Selectin Levels Equivalent Markers of Platelet Activation?

This study examines the relationship between soluble P-selectin (PS), platelet bound PS by flow cytometry, and conventional markers of platelet activation, such as platelet aggregometry, in patients undergoing physiological stress expected to produce platelet activation. Blood samples were taken following exercise in 20 patients with intermittent claudication, and from 20 patients within 24hrs of an acute ischaemic stroke. the study shows that soluble PS, but not platelet bound PS correlates with direct measurement of spontaneous platelet aggregation.