Nephrology and Kidney Injury Flashcards
7 cards from real Internal Medicine Exam practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Nephrology and Kidney Injury flashcards as text
A 60-year-old man with gout and CKD has a serum uric acid of 11 mg/dL. He starts allopurinol and develops a severe desquamating rash with hepatitis. Which HLA allele is strongly associated with allopurinol hypersensitivity syndrome?
Answer: HLA-B*58:01
HLA-B*58:01 is strongly associated with allopurinol-induced severe cutaneous adverse reactions, particularly in patients of Asian descent.
A 45-year-old HIV-positive man on tenofovir develops proximal tubular dysfunction with glucosuria (normal serum glucose), phosphaturia, and aminoaciduria. What syndrome does this represent?
Answer: Fanconi syndrome
Tenofovir causes mitochondrial toxicity in proximal tubules, leading to Fanconi syndrome with generalized proximal tubular dysfunction.
A 55-year-old woman develops oliguric AKI after prolonged hypotension during cardiac surgery. Urine microscopy shows muddy-brown granular casts. Urine sodium is 55 mEq/L and FENa is 3.2%. What is the mechanism?
Answer: Ischemic acute tubular necrosis
Ischemic ATN follows prolonged hypoperfusion, manifesting as muddy-brown granular casts, high urine sodium (>40 mEq/L), and FENa >1% due to tubular injury.
A 38-year-old woman with hypertension refractory to three medications has a serum potassium of 2.8 mEq/L and metabolic alkalosis. Aldosterone-to-renin ratio is 40 (ng/dL)/(ng/mL/hr). CT shows a 1.8 cm left adrenal adenoma. What is the best next step?
Answer: Perform adrenal vein sampling
Adrenal vein sampling is required before surgery to confirm unilateral aldosterone hypersecretion, as CT can miss contralateral disease or misidentify non-functioning adenomas.
A 30-year-old man with no past history develops cola-colored urine, periorbital edema, and hypertension 3 weeks after a streptococcal pharyngitis. C3 is low, C4 is normal. Renal biopsy would most likely show:
Answer: Subepithelial (humps) deposits on electron microscopy
Post-streptococcal GN shows subepithelial hump-shaped deposits on electron microscopy and granular IgG/C3 on immunofluorescence, with selective C3 consumption.
A 65-year-old man with CKD stage 4 has serum bicarbonate of 16 mEq/L. He has muscle wasting and accelerated bone disease. What is the most appropriate treatment for his metabolic acidosis?
Answer: Oral sodium bicarbonate supplementation
Oral sodium bicarbonate supplementation slows CKD progression, preserves muscle mass, and reduces bone disease by correcting the acidosis-driven protein catabolism.
A 50-year-old man with Wegener granulomatosis (GPA) presents with hematuria, proteinuria, and rising creatinine. Renal biopsy shows a pauci-immune crescentic glomerulonephritis. Which antibody is most likely positive?
Answer: c-ANCA (PR3-ANCA)
GPA (Wegener's) is associated with c-ANCA targeting proteinase 3 (PR3), while microscopic polyangiitis is more commonly p-ANCA/MPO-positive.