American Board of Internal Medicine (ABIM) Certification Practice Exam

Which clinical feature is commonly associated with cholesterol embolization leading to acute kidney injury?

1. Hyperkalemia

2. Peripheral eosinophilia

3. Eosinophiluria

4. Renal calculi

The correct answer is: Peripheral eosinophilia

Cholesterol embolization, often associated with atheroembolism, can lead to acute kidney injury through the occlusion of renal microvasculature by cholesterol crystals. Peripheral eosinophilia is a notable feature in this condition, as it indicates an inflammatory response to the cholesterol crystals that have been released into the circulation and subsequently lodged in various tissues. In the context of cholesterol embolization, the presence of eosinophils in the bloodstream suggests an immune response to the damaged endothelial cells and lipids involved in the embolization process. This eosinophilia can be quite pronounced and is often used as a clinical marker in diagnosing cholesterol crystal embolization syndromes. Other clinical features associated with acute kidney injury may arise, but peripheral eosinophilia stands out specifically because of its unique relationship to the underlying pathophysiology of cholesterol embolization. While options like hyperkalemia and eosinophiluria can occur due to kidney dysfunction or inflammatory processes, they do not provide the same direct indication of the cholesterol embolization phenomenon as peripheral eosinophilia does. Renal calculi, meanwhile, are unrelated and involve a different etiology entirely. Hence, among the options given, peripheral eosinophilia is the most directly