Platelet-leukocyte interactions in coronary heart disease: pathophysiology, clinical relevance, pharmacological modulation.

The interactions between leukocytes and endothelial cells have been studied extensively under conditions of ischemia and reperfusion. In contrast, att raction of leukocytes by platelets at the site of damage is poorly understo od. This recruitment facilitates inflammation and atherogenesis. Studies pe rformed ex vivo in coronary artery disease show that neutrophil-platelet ad hesion increases in unstable angina, coronary angioplasty and coronary arte ry bypass surgery, in comparison with stable angina. Experimental works hav e shown the major role of platelet P-selectin in platelet-leukocyte interac tions, and of fibrinogen, which is the ligand of both platelets and leukocy tes (beta2 integrins). Studied performed in anti-GPIIb/IIIa-treated patient s demonstrate a modulation, as inhibition, of platelet-leukocyte interactio ns. This new drug inhibits platelet function and coagulation, and moreover inflammation.