3169 Drugs! A New Mimicker of Primary Sclerosing Cholangitis

Abstract

INTRODUCTION: In the United States, drug-induced liver injury (DILI) is the most common cause of acute liver failure necessitating liver transplantation. DILI can be characterized biochemically based on specific patterns of injury - hepatocellular, cholestatic, or mixed. Detection of bile-duct strictures on magnetic resonance cholangiopancreatography (MRCP) is uncommon in DILI, and nearly pathognomonic for primary sclerosing cholangitis (PSC). Here we present two cases of “PSC-like DILI.” CASE DESCRIPTION/METHODS: Patient 1: A 68-year-old man with type 2 diabetes mellitus (T2DM) and hyperlipidemia was admitted for sepsis secondary to methicillin-sensitive staphylococcus aureus right wrist abscess, and subsequently started on cefazolin. He developed acute hepatitis with aspartate transaminase (AST) 665, alanine aminotransferase (ALT) 367, and alkaline phosphatase (ALP) 2317. Extensive work-up, including ferritin, anti-nuclear antibody (ANA), anti-mitochondrial antibody (AMA), anti-smooth muscle antibody (SMA), and viral serology, was unremarkable. MRCP showed multi-focal areas of intra-hepatic biliary ductal dilation and mild strictures without evidence of stones or malignancy, consistent with PSC. Liver biopsy was non-specific, demonstrating portal and lobular hepatitis with mild bile duct injury, and mild steatosis without steatohepatitis. Colonoscopy did not show inflammatory bowel disease. DILI with drug-induced PSC-phenomenon was suspected. The patient's liver function tests (LFTs) normalized within 24 hours of stopping cefazolin. Patient 2: A 63-year-old woman with T2DM was found to have AST 229, ALT 186, and ALP 652, 5 months after starting atorvastatin for stroke. MRCP revealed abnormal appearance of the central intrahepatic bile ducts (Figure 1). Ferritin, alpha-1 anti-trypsin, ceruloplasmin, and viral serology were unremarkable. ANA, SMA, and immunoglobulin G were elevated, suggestive of an immunologic process. Anti-liver-kidney-microsomal antibody and AMA, however, were negative. The patient was presumed to have a drug-induced autoimmune and cholestatic reaction with PSC-cholangiographic findings. LFTs normalized within 2-months after cessation of the statin. DISCUSSION: DILI with concurrent findings of bile-duct strictures on MRCP has yet to be described in the literature. The first case suggests cefazolin as the culprit, while the second points to atorvastatin as the suspected trigger for DILI and an “autoimmune-PSC overlap syndrome.” Clinicians should be aware that DILI can mimic PSC.