Platelets pave the way The interaction between leukocytes and platelets

Activated platelets express several adhesive molecules, like P-Selectin and CD40L. Platelets are able to interact with all types of leukocytes, indicating that platelets can act beyond hemostasis and thrombosis. Increased numbers of circulating platelets in plasma are associated with many pathological conditions. Inflammatory diseases show increased platelet activation. And hence platelets release proinflammatory cytokines after activation. In this paper the most important platelet adhesion receptors are described. In general, platelets stimulate immune responses by recruiting leukocytes and initiating them, enhancing the immune system. In contrast, the platelet role in atherosclerosis and cancer is not beneficial to patients as a result of the exacerbating effect of platelets on these diseases. Platelets increase atherosclerotic lesion formation by stimulating infiltration of leukocytes. Besides, platelets coat tumor cells and improve metastasis. After all, platelets are therefore of therapeutic interest. Inhibition of platelet adhesion receptors could lead to novel strategies in atherosclerosis and cancer therapies