Elevation of Endothelial Microparticles, Platelets, and Leukocyte Activation in Patients With Venous Thromboembolism

• Published in: Journal of the American College of Cardiology 2005-05, Vol.45 (9), p.1467-1471
• Main Authors: Chirinos, Julio A., Heresi, Gustavo A., Velasquez, Hermes, Jy, Wenche, Jimenez, Joaquin J., Ahn, Eugene, Horstman, Lawrence L., Soriano, Andres O., Zambrano, Juan P., Ahn, Yeon S.
• Format: Article
• Language: English
• Subjects: Acute coronary syndromes; Biological and medical sciences; Biomarkers - analysis; Blood and lymphatic vessels; Blood clots; Blood platelets; Blood Platelets - metabolism; Cardiology; Cardiology. Vascular system; Case-Control Studies; Defects; Diseases of the peripheral vessels. Diseases of the vena cava. Miscellaneous; Drug therapy; E-Selectin - analysis; Embolisms; Endothelium; Endothelium, Vascular - pathology; Female; Flow Cytometry; Humans; Hypertension; Leukocytes; Leukocytes - metabolism; Male; Medical imaging; Medical sciences; Middle Aged; P-Selectin - analysis; Plasma; Platelet Activation; Platelet Endothelial Cell Adhesion Molecule-1 - analysis; Pulmonary arteries; Pulmonary Embolism - blood; Studies; Thrombosis; Veins & arteries; Venous Thrombosis - blood; Ventilation
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/j.jacc.2004.12.075

The purpose of this research was to determine the levels of platelet, leukocyte, and endothelial activation and markers of cellular interactions in patients with venous thromboembolism (VTE). The details of interactions between endothelium, platelets, and leukocytes in VTE are not well understood. We studied 25 patients with VTE and compared 25 healthy controls. We used flow cytometry to measure: 1) endothelial microparticles (EMP) identified by CD31+/CD42b− (EMP31) or E-selectin (EMP62E); 2) platelet microparticles (CD31+/CD42b+); 3) surface expression of P-selectin in platelets and CD11b in leukocytes; 4) EMP-monocyte conjugates (percentage of monocytes positive for E-selectin); and 5) platelet-leukocyte conjugates (PLC) expressed as percentage of leukocytes positive for CD41. Patients with VTE had marked elevations of EMP31(2,193 vs. 383 counts/μl; p = 0.003), EMP62E(368 vs. 223 counts/μl; p = 0.001), and EMP-monocyte conjugates (3.3% vs. 2.5%; p = 0.002), as well as increased activation of platelets (35.2 vs. 5.0 fluorescence intensity units for P-selectin; p < 0.0001) and leukocytes (13.9 vs. 7.7 U for CD11b; p = 0.004). Also elevated in VTE were PLC (61.7% vs. 39.6%; p = 0.01). Expression of CD11b in leukocytes strongly correlated with PLC (r = 0.74; p < 0.0001). Marked activation of endothelium, platelets, and leukocytes occurs in VTE, and VTE, or the accompanying inflammatory process, involves the release of EMP and formation of EMP-monocyte conjugates and PLC. These findings support prior studies suggesting that release of EMP and their binding to monocytes are key events in thrombogenesis. Our findings also support the concept that the formation of PLC regulates leukocyte activation and participates in linking thrombosis with inflammation.