Transfusion Therapy with Platelet Concentrates

At the end of 1960, the concept that platelet transfusion could reduce the death rate due to hemorrhage was confirmed by the reduction of life-threatening bleeding and prolonged survival in thrombocytopenic patients affected with acute leukemia and aplastic anemia. Thrombocytopenia is the result of an imbalance between platelet production and destruction: usually no bleeding problem will occur until circulating platelets fall below 20000/μl and even a platelet count of 5000/μl may be present in many patients without bleeding. Because of the high risk of alloimmunization in multiply transfused thrombocytopenic patients with random platelet concentrates, the main dilemma is the choice of strategy: “prophylactic”versus “therapeutic” treatment with platelet concentrates of cancer patients and the platelet count selected as the “transfusion trigger” for platelet support in patients without active bleeding. We describe our experience of 367 retrospective non-randomized leukemic patients transfused with platelet concentrates. A total of 225 patients (61.3%) received support therapy: the transfusions were administered prophylactically at a platelet count below 20000/μl in the group of patients with acute lymphoblastic leukemia (35% transfused) and acute myeloblastic leukemia (78% transfused). Only14 hemorrhagic episodes were observed in 148 patients receiving prophylactic platelets (9%), while 21 severe hemorrhages (27%) were documented in patients treated with therapeutic platelet concentrates. Several studies have concluded that maintaining the platelet count above 20000/μl was not justified in the majority of cancer patients. In the absence of more definitive data, a “transfusion trigger” of 10000/μl is selected for platelet transfusion support in leukemic non-bleeding patients receiving chemotherapy.