A Unique Case of Accelerated Common Bile Duct Stones/Biliary Sludge Secondary to Tacrolimus Use in a Kidney Transplant Recipient

Abstract

Purpose: Organ transplant recipients are at high risk for complications of biliary calculi. Use of certain immunosuppressant's has been associated with increased incidence of cholelithiasis with exact etiology being unknown. We show a unique example of accelerated common bile duct (CBD) stone and biliary sludge formation over a short period of time in a patient taking tacrolimus. A 48-year-old Hispanic male with end stage renal disease status post two kidney transplants on tacrolimus, presented with complaint of intermittent colicky epigastric pain for two weeks getting progressively worse, aggravated by food and associated with nausea and vomiting. Physical exam revealed icterus of sclera and skin with epigastric tenderness. Lab studies revealed protein= 7.2, albumin=3.5, bilirubin=6.7 (conjugated=1.3), ALP=381, AST=108 &\and ALT=73. Imaging studies revealed marked intra and extrahepatic biliary dilation with suspected choledocolithiasis with no evidence of gallstones. Endoscopic retrograde colangiopancreatography (ERCP) revealed multiple filling defects of more than 1 cm, which was consistent with CBD stones. Adequate size sphincterotomy was performed and plastic stent was placed. Subsequently, he underwent cholecystectomy and CBD exploration with T-tube placement. T-tube cholangiogram was performed, with no evidence of biliary stricture or calculi seen. He presented again after 11 weeks with similar symptoms. Laboratory studies revealed protein=7.8, albumin=4.1, bilirubin=5.3 (conjugated=1.3), ALP=233, AST=102 and ALT=188. Imaging revealed marked intra and extrahepatic biliary dilation with absent gallbladder. ERCP was performed revealing multiple CBD stones & biliary sludge. Review of literature shows that some adverse effects from tacrolimus result in increased incidence of biliary sludge and gallstone formation. Regular ultrasound to detect biliary disease is recommended in such patients. Cholecystectomy is also indicated in patients showing evidence of cholecystitis. However, there are no reports of CBD stone and biliary sludge formation in such a short interval of time in post-sphincterotomy patient as seen in our case. We hypothesize that relapse of stone formation in our patient was due to usage of tacrolimus. Controlled studies are needed to investigate exact incidence and to document association between accelerated CBD stone formation/biliary sludge and tacrolimus use. Exact mechanism for formation of CBD stones and biliary sludge in such a short time interval in such patients remains unknown.