Bile Cast Nephropathy in Cirrhotic Patients: Effects of Chronic Hyperbilirubinemia

Abstract

Objectives: The aim of this study was to determine the prevalence of bile cast nephropathy (BCN) in autopsied cirrhotic patients and to correlate BCN with clinical and laboratory data to direct attention to this underrecognized renal complication of liver failure.

Methods: We assessed 114 autopsy cases of cirrhosis for the presence of renal intratubular bile casts using Hall stain for bile. Presence of bile casts was correlated with etiology of cirrhosis, clinical and laboratory data, and histologic findings.

Results: Bile casts were identified in 55% of cases. The most common etiology of cirrhosis was hepatitis C virus (HCV) infection (52%), and serum creatinine ( P = .02) and serum urea nitrogen ( P = .01) were significantly higher in the Hall-positive group. Conjugated bilirubin was below 20 mg/dL in 90%, and levels below 10 mg/dL were noted in 80% of cases.

Conclusions: To our knowledge, this is the largest study of BCN in human subjects and a first report describing the association of BCN with HCV-related cirrhosis. We demonstrated that in the face of protracted chronic hyperbilirubinemia, bile casts are formed at much lower bilirubin levels than previously thought. Furthermore, we proposed an algorithm to assist in better identification of bile casts.

Keywords: Bile cast nephropathy; Cirrhosis; Hyperbilirubinemia.