Flow Cytometric Quantitation of Procoagulant Microparticles and Erythrocyte Phosphatidylserine Exposure in B-Thalassemia Patients

Abstract

halassemia is one of the most common hereditary hemolytic anemias. It results from partial or complete lack of synthesis of one of the Hb globin chains (α or β chains). The commonest type in Egypt is β-thalassemia. Many complications seen in β-thalassemia are related to ineffective erythropoiesis and iron overload. Recent advances in evaluation and treatment of iron overload (over the last 10 - 20 years) have led to a dramatic improvement in the management of thalassemic patients and increased their life expectancy. Yet, new complications have emerged. Thromboembolic events are being recently identified among β-thalassemia patients. The hypercoagulable state has been attributed to many hemostatic alterations, including the elevated numbers of MPs. Microparticles are phospholipid microvesicles shed from the plasma membrane of cells undergoing activation or apoptosis. These MPs originate from circulating blood cells, platelets, and endothelial cells. Most MPs are highly procoagulant, expressing annexin V binding sites, and are able to participate in various physiologic and pathologic processes, especially inflammation and thrombosis. Oxidative stress is one of the risk factors involved in increasing the MPs formation. Elevated levels of MPs have been reported in many vascular diseases, thalassemia, sepsis, diabetes and pre-eclampsia.