Primary biliary cholangitis vs Primary sclerosing cholangitis
How to tell Primary biliary cholangitis and Primary sclerosing cholangitis apart when a board question makes them look alike.
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Positive antimitochondrial antibody is the quickest discriminator for primary biliary cholangitis.
Side by side
Cholestatic enzymes in a middle-aged woman with positive antimitochondrial antibodies point to primary biliary cholangitis.
Cholestatic liver profile in a man with inflammatory bowel disease and multifocal duct strictures points to primary sclerosing cholangitis.
Autoimmune destruction of small intrahepatic bile ducts causes chronic cholestasis and fibrosis.
Inflammatory fibrosis of intrahepatic and extrahepatic bile ducts causes multifocal stricturing and cholestatic injury.
PBC typically shows alkaline phosphatase elevation, positive AMA at high titer, and biopsy with nonsuppurative destructive cholangitis of small ducts when diagnosis is uncertain.
PSC usually shows cholestatic enzymes with MRCP beading from alternating strictures and dilation in large ducts, often with p-ANCA positivity and coexisting ulcerative colitis.
The trap
Pruritus and cholestatic labs in both conditions can mislead clinicians to treat empirically without duct imaging; negative AMA or known ulcerative colitis should prompt MRCP to look for beaded large-duct disease.
The repair move
Next best step: confirm cholestatic pattern, check AMA first, start ursodeoxycholic acid 13 to 15 mg/kg/day for confirmed PBC, and if AMA is negative or clinical context suggests PSC obtain MRCP and arrange colonoscopy screening for associated colitis and cholangiocarcinoma surveillance.
Try a free question
CoreA 42-year-old woman has progressive fatigue and pruritus. BP 128/74 mm Hg, HR 80/min, temp 36.5 C. Labs: alkaline phosphatase 390 U/L, AST 62 U/L, ALT 58 U/L, bilirubin 1.6 mg/dL. AMA is positive. What is the next best step in management?
Show answer and explanation
Answer: A. Start ursodeoxycholic acid therapy. Confirmed PBC is treated first-line with ursodeoxycholic acid to slow progression.
Why the other choices are tempting
- B. Wrong because routine corticosteroids are not first-line disease-modifying treatment for PBC.
- C. Wrong because ERCP is for dominant strictures or cholangitis, not initial uncomplicated AMA-positive PBC.
- D. Wrong because this is not viral hepatitis based on serology and cholestatic pattern.
- E. Wrong because untreated PBC progresses to fibrosis and requires active management.
Flashcards
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In cholestatic liver disease, which antibody finding most strongly supports primary biliary cholangitis?
A positive antimitochondrial antibody strongly supports primary biliary cholangitis.
Which imaging hallmark supports primary sclerosing cholangitis over primary biliary cholangitis?
MRCP showing multifocal strictures with segmental dilation, the beaded-duct pattern, supports PSC.
Quick answers
What is the fastest way to tell Primary biliary cholangitis from Primary sclerosing cholangitis?
Positive antimitochondrial antibody is the quickest discriminator for primary biliary cholangitis.
What is the key clue for Primary biliary cholangitis?
Cholestatic enzymes in a middle-aged woman with positive antimitochondrial antibodies point to primary biliary cholangitis.
What is the key clue for Primary sclerosing cholangitis?
Cholestatic liver profile in a man with inflammatory bowel disease and multifocal duct strictures points to primary sclerosing cholangitis.
What is the common trap with Primary biliary cholangitis vs Primary sclerosing cholangitis?
Pruritus and cholestatic labs in both conditions can mislead clinicians to treat empirically without duct imaging; negative AMA or known ulcerative colitis should prompt MRCP to look for beaded large-duct disease.