Renal Fanconi Syndrome Secondary to Deferasirox: Where There Is Smoke There Is Fire

Abstract

The kidney filters ~150 liters per day and reabsorbs 99% of this ultrafiltrate of plasma. The renal tubule is segmented and different portions of the nephron have selective roles in solute and volume reabsorption. The proximal tubule reabsorbs four-fifths of the filtered bicarbonate, two-thirds of the filtered chloride, and essentially all of the filtered glucose, amino acids, and phosphate. Thus, significant injury to the proximal tubule leads to volume depletion, metabolic acidosis, and hypophosphatemia. Hypokalemia is also a common manifestation as aldosterone levels are elevated due to volume depletion and there is increased delivery of sodium and bicarbonate to the distal nephron where sodium is reabsorbed causing a lumen negative potential leading to potassium secretion across an apical potassium channel. Hypomagnesemia is also a common feature of the Fanconi Syndrome.