Abstract: TH-PO057
Bile Cast Nephropathy: A Diagnostic Odyssey Beyond Hepatorenal Syndrome
Session Information
- AKI: Liver Disease, Nephrotoxicity, Novel Therapeutics
November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Acute Kidney Injury
- 102 AKI: Clinical, Outcomes, and Trials
Authors
- Samant, Samira Mahesh, The Permanente Medical Group Inc, Santa Clara, California, United States
- Cortesi, Camilo, The Permanente Medical Group Inc, Santa Clara, California, United States
Introduction
Bile cast nephropathy (BCN) is a rarely recognized and often overlooked complication of hyperbilirubinemia leading to acute kidney injury (AKI). We present a case of BCN in a patient with alcohol hepatitis initially managed as hepatorenal syndrome (HRS).
Case Description
A 66-year-old male with severe alcohol abuse and baseline creatinine of 1.5 mg/dL presented with altered mental status and acute alcohol intoxication, requiring ICU admission. Laboratory tests showed AST 751 U/L, ALT 238 U/L, ALKP 768 U/L, total bilirubin 22.9 mg/dL, direct bilirubin 12.4 mg/dL, INR 2.4, ammonia 181 umol/L, and creatinine 2.6 mg/dL with FENa 0.1%. Ultrasound revealed diffusely hyperechoic liver, diagnosing alcoholic hepatitis with impending liver failure. Glucocorticoids were initiated, with octreotide, albumin, and midodrine for HRS. However, renal function worsened as total bilirubin peaked at 54 mg/dL. Urine microscopy identified bile-stained granular casts, prompting reassessment of the initial HRS diagnosis.
Discussion
HRS is often considered in AKI with liver dysfunction, but urine microscopy should not be overlooked. In AKI, urine microscopy to rule out BCN is crucial, especially when total bilirubin exceeds 20 mg/dL. Bilirubin's nephrotoxic effects involve oxidative damage to renal tubules, bile cast obstruction, and toxicity of sulfated bile salts. Renal biopsy for definitive diagnosis is unsafe in liver disease due to coagulopathy. Treatment focuses on improving hepatic function and relieving biliary obstruction if present. Timely diagnosis and intervention can reverse renal injury; refractory cases may require plasmapheresis or dialysis. Steroids, ursodeoxycholic acid, and lactulose provide minimal benefit. This case highlights the challenges of differentiating BCN from HRS, emphasizing the importance of urine microscopy.
Bile-stained granular casts