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Primary biliary cholangitis — ABIM Board MCQ

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ModerateGastroenterology/HepatologyPrimary biliary cholangitisABIM Board

A 55-year-old woman has several months of pruritus and fatigue. Laboratory studies show an alkaline phosphatase level of 486 U/L, AST of 72 U/L, ALT of 68 U/L, and total bilirubin of 1.4 mg/dL. Antimitochondrial antibody testing is positive. Abdominal ultrasonography shows no intrahepatic or extrahepatic biliary dilation. She does not drink alcohol, and viral hepatitis testing is negative. Which of the following is the most appropriate initial disease-modifying treatment?

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Correct answer: E — Ursodeoxycholic acid (ursodiol)

The cholestatic biochemical pattern, positive antimitochondrial antibody, and absence of extrahepatic obstruction establish primary biliary cholangitis. Ursodeoxycholic acid (ursodiol), generally 13–15 mg/kg/day, is the initial disease-modifying therapy and improves liver biochemistry and clinical outcomes. Cholestyramine can be added for cholestatic pruritus but does not replace ursodiol; because it reduces ursodiol absorption, administration should be separated. Prednisone plus azathioprine is used for autoimmune hepatitis or a well-supported overlap syndrome, neither of which is demonstrated here. Endoscopic sphincterotomy treats selected mechanical biliary obstruction, which ultrasonography does not suggest. Liver biopsy is not routinely required when cholestatic tests and antimitochondrial antibodies establish the diagnosis, and observation without treatment permits disease progression.

Reference: US Food and Drug Administration. URSO 250 and URSO FORTE (ursodiol) Prescribing Information, sections 1, 2.1, and 14.1; revised 2023. https://www.accessdata.fda.gov/drugsatfda_docs/label/2023/020675s028lbl.pdf