Which concept should the nurse include when describing the pathophysiology of thrombotic thrombocytopenic purpura?

• A. Megakaryocytes
• B. Erythroblasts
• C. Platelets
• D. Schistocytes

Answer: (D)

Schistocytes on a peripheral smear signal red blood cell fragmentation from shear stress in narrowed vessels, which is the hallmark of thrombotic microangiopathy like thrombotic thrombocytopenic purpura. In TTP, a severe deficiency of ADAMTS13 allows ultra-large von Willebrand factor multimers to persist, promoting widespread platelet-rich microthrombi in small vessels. As red blood cells traverse these obstructed channels, they are mechanically damaged, creating schistocytes. This ongoing microangiopathic hemolysis explains both the anemia and the low platelet count, since platelets are consumed in the forming thrombi. Megakaryocytes and erythroblasts aren’t central to this process, while platelets matter as part of the thrombi, the most distinctive feature to describe is the red cell fragmentation—schistocytes—driven by microthrombi in small vessels.