New strategies for prophylactic platelet transfusion in patients with hematologic diseases.

There is an increasing demand for platelet transfusions due to intensive chemotherapy and blood stem cell or bone marrow transplantation for the treatment of hematologic and oncologic diseases. There has been a long-lasting debate over whether the traditional threshold for prophylactic platelet transfusion of 20,000/microl is really necessary to prevent hemorrhagic complications. During the last 10 years several studies with more than 1,000 patients together have proven the safety of a platelet transfusion trigger of 10,000/microl or even lower when patients are clinically stable without active bleeding. This experience has been mostly gathered in patients with acute leukemia. But this stringent platelet transfusion policy can be used also after blood stem cell and bone marrow transplantation. In stable patients with aplastic anemia and myelodysplasia, prophylactic transfusions should be replaced in most patients by a therapeutic transfusion strategy. Such restrictive platelet transfusion strategies decrease the risk of infectious disease transmission, immunization, and febrile transfusion reactions. Besides reduced hospital visits and a shorter hospital stay for the patients, the costs for platelet transfusions are lowered by 20%-30% compared with traditional transfusion strategies. The decision to administer platelet transfusions should incorporate individual clinical characteristics of the patients and not simply be a reflexive reaction to the platelet count. Further clinical studies are needed to answer the still open question of whether patients with acute leukemia should also be transfused therapeutically rather than prophylactically when they are in stable condition without signs of active bleeding.