The Issues
One major function of platelets is to contribute to hemostasis: the process of stopping bleeding at the site of interrupted endothelium. They gather at the site and unless the interruption is physically too large, they plug the hole. First, platelets attach to substances outside the interrupted endothelium: adhesion. Second, they change shape, turn on receptors and secrete chemical messengers: activation. Platelets also participate in both innate and adaptive intravascular immune responses.
Thus, platelets transfusions are needed to treat “thrombocytopenia” which is a decrease in platelet concentration that is induced by a large number of diseases, many with a rising incidence due to population