Thalassemia and the hypercoagulable state.

Thalassemia, an inherited hemolytic disorder, is associated with a high incidence of thrombosis. The major mechanisms underlying thromboembolism (TE) are an abnormal red blood cell surface, platelet activation and endothelial cell activation. A higher risk of TE is found in splenectomized patients due to thrombocytosis and increased abnormal RBCs in the circulation. Regular RBC transfusions can reduce the proportion of abnormal RBCs and suppress erythropoiesis. Regular transfusion may also reduce levels of circulating coagulation markers and reduce elevated pulmonary artery pressure. To prevent thromboembolic events, aspirin is now recommended for splenectomized patients with thrombocytosis.