Indication of prophylactic platelet transfusion in aplastic anemia.

We have retrospectively analyzed the relationship between the platelet counts and severe hemorrhagic episodes in 56 patients with aplastic anemia with platelet counts lower than 20, 000/μl to establish better standardization for indications of prophylactic platelet transfusion in aplastic anemia. Severe hemorrhagic episodes, especially cerebral bleeding, occurred more frequently in patients with the platelet counts below 5, 000/μl than 5, 000 to 20, 000/μl, mostly within 6 months after platelet counts fell below 5, 000/μl. On the other hand, most of patients with no severe hemorrhagic episodes in spite of platelet counts below 5, 000/μl recovered by therapy or died of infection within 3 months. Seventeen out of 21 patients who were complicated with cerebral bleeding were supposed to have died because of ineffectiveness or delay of platelet transfusions. From the history of platelet transfusions, it was speculated that at least in 6 patients cerebral bleeding could have been prevented by adeqate prophylactic platelet transfusions.From these findings, we have proposed a scoring system to determine the indications of platelet transfusions in aplastic anemia. In this proposal, prophylactic platelet transfusions are necessary at least for 6 months in patients the platelet counts last below 5, 000/μl, irrespective of the degree of bleeding symptoms and the complications of infections or DIC.