Glanzmann's Thrombasthenia; Assessment of the Response to Platelet Transfusions

The response to platelet transfusions was studied in 2 patients with Glanzmann's thrombasthenia. Glanzmann's thrombasthenia is an autosomal recessive disorder of platelets characterized by normal platelet count, prolonged bleeding time, absent platelet aggregation, and defective clot retraction. Antibodies to platelets were detected in 1 patient who had failed to respond to platelet transfusions, and bled during and after surgery despite fresh whole blood transfusions. The other patient had no detectable antiplatelet antibodies, exhibited improved platelet function when normal platelets were added to her platelet rich plasma and experienced a favorable response to platelet transfusions during major surgery. These cases demonstrate the importance of antiplatelet antibodies as a determinant of a patient's response to platelet transfusion, the value of this therapy in qualitative platelet disorders, and the potential usefulness of in vitro studies to predict the outcome of platelet transfusions in such patients.