Cappellini M D, Grespi E, Cassinerio E, Bignamini D, Fiorelli G
Department of Internal Medicine, Hereditary Anemia Center, Fondazione Policlinico, Mangiagalli, Regina Elena, IRCCS, University of Milan, Milan, Italy.
Ann N Y Acad Sci. 2005;1054:317-24. doi: 10.1196/annals.1345.039.
Venous thromboembolic events, such as pulmonary embolism, deep venous thrombosis, and portal vein thrombosis, have been observed in adult thalassemia patients, mainly in beta-thalassemia intermedia. The clinical findings are consistent with the observation of several alterations that indicate a state of activation of the hemostatic mechanisms in thalassemias. These alterations have usually been related to high platelet counts due to splenectomy and/or liver dysfunction. In a retrospective study of a large cohort of adults with thalassemia, we found a larger prevalence of venous thromboembolic events in transfusion-independent patients with thalassemia intermedia (29%) than in regularly transfused patients with thalassemia major (2%); moreover, the higher prevalence occurred particularly in splenectomized thalassemia intermedia patients. More recently, a multicenter study involving 56 tertiary referral centers in 7 countries was planned to assess the magnitude of thrombotic risk in thalassemia patients. The total number of patients who had thrombotic events was 146 (1.65%) out of 8860, with a prevalence of 0.9% in thalassemia major and 4% in thalassemia intermedia. The highest prevalence was confirmed in splenectomized patients. The observation that thrombotic events are more frequent in beta-thalassemia patients who are not receiving regular transfusions (thalassemia intermedia or thalassemia major patients in less developed countries with limited transfusion resources) or in thalassemic patients who have undergone splenectomy strongly supports the procoagulant activity of circulating damaged red blood cells.
静脉血栓栓塞事件，如肺栓塞、深静脉血栓形成和门静脉血栓形成，已在成年地中海贫血患者中观察到，主要见于中间型β地中海贫血。临床发现与观察到的几种改变一致，这些改变表明地中海贫血患者存在止血机制激活状态。这些改变通常与脾切除和/或肝功能障碍导致的高血小板计数有关。在一项对大量成年地中海贫血患者的回顾性研究中，我们发现，中间型地中海贫血非输血依赖患者（29%）发生静脉血栓栓塞事件的患病率高于重度地中海贫血定期输血患者（2%）；此外，较高的患病率尤其出现在脾切除的中间型地中海贫血患者中。最近，一项涉及7个国家56个三级转诊中心的多中心研究计划评估地中海贫血患者的血栓形成风险程度。在8860名患者中，发生血栓事件的患者总数为146例（1.65%），重度地中海贫血的患病率为0.9%，中间型地中海贫血为4%。脾切除患者的患病率最高。未接受定期输血的β地中海贫血患者（中间型地中海贫血患者或输血资源有限的欠发达国家的重度地中海贫血患者）或接受过脾切除的地中海贫血患者血栓事件更频繁这一观察结果有力地支持了循环受损红细胞的促凝活性。
