Hypercoagulability and thrombotic complications in hemolytic anemias

Abstract

Despite longstanding evidence for increased activation of coagulation in hemolytic anemias, its pathophysiology and its role in the vaso-occlusive crises of sickle disease remain unclear. Here Dr. Ataga reviews the latest evidence on this topic, emphasizing the likely multifactorial origin of the activation and the increasing evidence for the importance of cellular elements or their derived microparticles. See related articles on pages 1513 and 1520

Figure 1.

Schematic representation of pathophysiological mechanisms (described or postulated) leading to coagulation activation in sickle cell disease and other hemolytic anemias. Based on Virchow’s triad, the illustrated pathways contribute to activation of coagulation (and possibly eventual thrombosis) by one of three broad mechanisms, i.e.: (i) changes in the vessel wall; (ii) changes in blood flow; and/or (iii) changes in the composition of blood components (‘hypercoagulability’). Ab: antibody; NO:nitric oxide; PS: phosphatidylserine; RBC: red blood cell; MPs: microparticles; TF: tissue factor. (Adapted from Ataga KI, Key NS. Hypercoagulability in sickle cell disease: new approaches to an old problem. Hematology Am Soc Hematol Educ Program. 2007:91–96)