Review Question - QID 101434

Both traumatic hemolysis and microangiopathic hemolytic anemia produce red blood cell fragments and schistocytes (helmet cells) on peripheral blood smear.

Mechanical damage, such as that induced by a prosthetic valve, can cause excessive shear and turbulence in the cardiac circulation that damages red blood cells. The patient’s normal platelet count suggests that she is not suffering from microangiopathic anemia. Expected laboratory results also include a decreased hemoglobin level and an elevated reticulocyte percentage.

Dhaliwal et al. discuss the presentation and diagnosis of hemolytic anemia. They conclude that clinical presentation may include acute or chronic anemia, reticulocytosis, and jaundice. Characteristic laboratory findings include increased unconjugated bilirubin, increased lactate dehydrogenase, and decreased haptoglobin.

Bettadapur et al. review the clinical complication of prosthetic heart valves. They find that although severe hemolytic anemia is relatively uncommon, it may occur when RBCs are sheared and destroyed by turbulent blood flow across a foreign material such as a prosthetic cardiac valve.

Illustration A demonstrates schistocytes, which are fragmented and irregularly shaped RBCs.

Incorrect Answers:
Answer 1: Bite cells and Heinz bodies are characteristic of glucose-6-phosphate dehydrogenase (G6PD) deficiency.

Answer 2: Sickle cells and target cells are characteristic of sickle cell anemia.

Answer 4: Round macrocytes and target cells are characteristic of macrocytic anemia from chronic alcoholism.

Answer 5: Macrocytes and hypersegmented neutrophils are characteristic of megaloblastic anemia.