A 34-year-old woman with Sjogren syndrome presents with fatigue and recurrent nephrolithiasis. Vital signs: BP 132/88 mmHg, HR 92 bpm, RR 16/min, Temp 37.2°C, SpO2 98% on room air. Laboratory studies reveal normal anion gap metabolic acidosis (pH 7.32, HCO3 18 mEq/L), serum potassium 3.1 mEq/L, and urine pH 6.3. Serum creatinine is normal. No proteinuria noted. Which of the following is the most likely underlying renal tubular defect?
- A)Impaired hydrogen ion secretion by alpha intercalated cellsGABARITO
- B)Excess loop diuretic effect in the thick ascending limb
- C)Defective bicarbonate reabsorption in the proximal tubule
- D)Deficient aldosterone production causing impaired sodium reabsorption
- E)Constitutive epithelial sodium channel activation in the collecting tubule
Explicação
Type 1 distal renal tubular acidosis results from inability of alpha intercalated cells in the collecting duct to secrete hydrogen ions. The urine remains inappropriately alkaline, predisposing to calcium phosphate stones and hypokalemia. Ver explicação completa e trilha adaptativa →