Origins of platelet transfusion therapy.

In 1955, animal studies suggested that thrombocytopenia was not the initiating cause of hemorrhage. Coagulation studies in vitro revealed the correction of coagulation by fresh platelets. Platelets, freshly collected with use of nonwettable surfaces, corrected thrombocytopenia, controlled associated hemorrhage, and prevented death from bleeding. Thus, in vitro and animal studies can be misleading (bench to bedside). Careful clinical observations, elaborated by in vitro studies, which create hypotheses testable in the clinic, lead to therapeutic advances (bedside to bench and back). Platelet replacement for thrombocytopenia prevents the hemorrhagic diathesis and has been universally practiced for over 50 years.