Abstract: SA-PO385
Hyperbilirubinemia and Acquired Fanconi Syndrome
Session Information
- Genetic and Diagnostic Trainee Case Reports
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Report
- 902 Fluid and Electrolytes: Clinical
Authors
- Portocarrero caceres, Juan P., Loyola University MacNeal Hospital, Berwyn, Illinois, United States
- Alghezawi, Shamikh Emad shamekh, Jordan University of Science and Technology, Irbid, Jordan
- Ando, Akika, University of Illinois Medical Center, Chicago, Illinois, United States
- Toth-Manikowski, Stephanie M., University of Illinois Medical Center, Chicago, Illinois, United States
- Asmaro, Ragad, University of Illinois Medical Center, Chicago, Illinois, United States
Introduction
Bile cast nephropathy is characterized by renal dysfunction in the setting of severe hyperbilirubinemia. It is a rare condition that occurs as a result of direct toxicity from bile acids and from tubular obstruction by bile casts. Diagnosis requires a high degree of clinical suspicion and it should be differentiated from hepatorenal syndrome.
Case Description
A 32-year-old man with past medical history of alcoholic liver cirrhosis was admitted for generalized jaundice and dark-colored urine. He reported taking 1.5 grams of acetaminophen daily for 4 days prior to admission. He endorsed stopping alcohol intake 19 months prior to admission. Physical exam was significant for tachypnea, tachycardia, and generalized jaundice. He did not have neurological deficits. Laboratory studies demonstrated severe hypophosphatemia (<1 mEq/L), hypokalemia (2.3 mEq/L), non-oliguric kidney (creatinine of 1.6 mg/dL, unknown baseline), elevated anion gap (14), and hypoalbuminemia of 3 g/dL. Total bilirubin level was elevated at 49.7 mg/dL with a direct bilirubin >30 mg/dL. Blood urea nitrogen (BUN) level was 11 mg/dL. A urine sample revealed glucosuria. The urine sediment demonstrated bile casts. The calculated fractional excretion of phosphate in urine was 40%. He was initially treated for suspected acetaminophen toxicity and for decompensated liver failure with octreotide, midodrine, and albumin. He required aggressive intravenous infusion of phosphate and potassium. The patient was medically stabilized and all his electrolyte imbalances corrected. After peaking at 1.8 mg/dL, his creatinine improved to 1.4 mg/dL with supportive care.
Discussion
In this presentation, we attributed the cause of severe hypophosphatemia and non-oliguric acute kidney injury to bile cast nephropathy. Risk of bile cast formation increases when total bilirubin levels rise above 20 mg/dL. As a majority of filtered phosphate is reabsorbed in the proximal tubules (>80%), severe hyperbilirubinemia can lead to hypophosphatemia by way of proximal tubulopathy, more classically known as acquired Fanconi’s syndrome. Previous case reports have reported that the degree of hypophosphatemia is inversely correlated with bilirubinemia. As bile cast nephropathy is partially reversible, therapy should be focused on treating the cause of liver failure and correcting metabolic derangements.