Increased plasma levels of soluble selectins in patients with unstable angina

Background: Inflammation plays an important role in the pathogenesis of unstable angina. Adhesion molecules, such as selectins, mediate the interactions between leukocytes, platelets and endothelial cells during inflammation and thrombogenesis. Hypothesis: The purpose of this study was to determine whether soluble E-selectin, P-selectin and L-selectin levels are increased in patients with unstable angina (UA). Methods: Soluble E-, P- and L-selectin levels were measured by enzyme-linked immunoassay in the peripheral blood of 23 patients with UA, 26 patients with stable angina (SA) and 15 control patients with angiographically normal coronary arteries. Results: Soluble E-selectin levels were significantly higher in patients with UA (45±11 ng/ml) than in controls (30±8 ng/ml, P<0.001), or patients with SA (34±8 ng/ml, P=0.001). Similarly, plasma levels of P- and L-selectin were significantly higher in patients with UA (427±144 and 772±160 ng/ml, respectively) than in patients with SA (278±79 and 643±94 ng/ml, respectively, P<0.005 vs. UA for both), or control patients (189±43 and 601±126 ng/ml, respectively, P=0.001 vs. UA for both). Conclusions: Plasma levels of soluble selectins were increased in patients with UA compared with patients with SA or patients without angiographically visible coronary artery disease. Measurements of these adhesion molecules may be helpful as non-invasive markers of coronary plaque destabilization in UA.