A man who drank antifreeze develops high anion gap metabolic acidosis, flank pain and oliguria. Urine microscopy shows envelope-shaped birefringent crystals. Which structure bears the brunt of injury from these crystals?
- A Retinal photoreceptors
- B Renal tubules ✓
- C Cardiac conducting tissue
- D Hepatic sinusoids
Correct answer: B. Renal tubules
Explanation
Ethylene glycol is metabolised by alcohol dehydrogenase to glycolate and oxalate. Oxalate precipitates as calcium oxalate crystals, which deposit in and directly injure the proximal renal tubules, producing acute tubular necrosis and renal failure, while glycolate drives the acidosis. Retinal injury from formate is the hallmark of methanol, not ethylene glycol, and neither cardiac conduction tissue nor hepatic sinusoids are the principal targets here.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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