Bile cast nephropathy: A case report and review of the literature

Abstract

Bile cast nephropathy is a condition of renal dysfunction in the setting of hyperbilirubinemia. There are very few cases of this condition reported in the last decade and a lack of established treatment guidelines. While the exact etiology remains unknown, bile cast nephropathy is presumed to be secondary to multiple concurrent insults to the kidney including direct toxicity from bile acids, obstructive physiology from bile casts, and systemic hypoperfusion from vasodilation. Therapy directed at bilirubin reduction may improve renal function, but will likely need dialysis or plasmapheresis as well. We report our case of bile cast nephropathy and the therapeutic measures undertaken in a middle-aged male with chronic renal insufficiency that developed hyperbilirubinemia and drug-induced liver injury secondary to antibiotic use. He developed acute renal injury in the setting of rising bilirubin. He subsequently had a progressive decline in renal and hepatic function, requiring dialysis and plasmapheresis with some improvement, ultimately requiring transplantation.

Keywords: Bile cast, Dialysis, Drug-induced liver injury, Plasmapheresis, Hyperbilirubinemia

Core tip: The role of bilirubin in causing acute renal insufficiency is not well known. Our case report is one of few documenting evidence of renal insufficiency as a result of hyperbilirubinemia. Diagnosis requires a high index of suspicion in patients with hyperbilirubinemia with concomitant acute renal insufficiency. Renal biopsy is the solitary means of definitive diagnosis. Treatment is targeted at improving hepatic dysfunction and decreasing bilirubin burden. Numerous treatment modalities to reduce bilirubin have been suggested with variable outcomes.