North American Veterinary Licensing Examination (NAVLE) Practice Test

Which disease is characterized by the presence of schistocytes on a complete blood count?

1. Systemic lupus erythematosus

2. Disseminated intravascular coagulation

3. Methemoglobinemia

4. Acetaminophen toxicity

The correct answer is: Disseminated intravascular coagulation

The presence of schistocytes on a complete blood count is most commonly associated with disseminated intravascular coagulation (DIC). Schistocytes are fragmented red blood cells that result from mechanical destruction within the circulation. In DIC, there is widespread activation of the coagulation cascade, leading to the formation of microthrombi throughout the small blood vessels. As red blood cells pass through these narrowed or occluded vessels, they can be damaged, resulting in the formation of schistocytes. Hence, the detection of schistocytes serves as a key indicator of this condition. Other conditions mentioned may have varying effects on the blood cells, but they do not specifically result in the formation of schistocytes. For instance, systemic lupus erythematosus may cause anemia or thrombocytopenia but is not typically associated with schistocytes. Methemoglobinemia primarily affects the oxygen-carrying capacity of hemoglobin without leading to mechanical destruction of red blood cells. Acetaminophen toxicity is associated with liver damage and can cause hemolysis, but it does not typically result in schistocyte formation. Thus, schistocytes are a definitive sign of the pathological processes involved in DIC.