Autoimmune and Cholestatic Liver Disease

• Audio chapter
  Single-voice audio, listen on the commute.
• ABIM-format MCQs
  5-option vignettes with full wrong-answer teaching.
• Study guide
  Tables, decision trees, primary sources.
• AI tutor
  Chapter-grounded, answers the question you're stuck on.

What this chapter covers

• Section 20.1: Sorting AIH, PBC, and PSC

  The three classical immune liver diseases share a common conceptual frame, which is loss of tolerance to a self-antigen, and they separate by the cell type that the immune system attacks.

• Section 20.2: AIH diagnosis, histology, and treatment

  Autoimmune hepatitis is the immune attack on hepatocytes by activated T cells responding to self-antigens that have escaped tolerance, with B-cell-derived autoantibodies serving as serologic markers rather than effectors.

• Section 20.3: PBC diagnosis, histology, and natural history

  Primary biliary cholangitis is a slowly progressive autoimmune cholangiopathy in which T cells attack the small intralobular bile duct epithelium and produce a destructive non-suppurative cholangitis with progressive ductopenia and fibrosis.

• Section 20.4: PBC first-line and second-line therapy

  The PBC treatment algorithm starts with universal use of UDCA, then escalates by biochemical response, with the modern second-line landscape expanded by three FDA-approved agents that target nuclear receptors involved in bile acid homeostasis.

• Section 20.5: PBC pruritus management

  Pruritus is the most common symptom in PBC, frequently precedes biochemical disease, and worsens disability scores more than fatigue in many patients.

• Section 20.6: PSC diagnosis and natural history

  Primary sclerosing cholangitis is the chronic immune-mediated inflammation and fibrotic stricturing of the intra and extrahepatic bile ducts, producing the classic multifocal stricture pattern with intervening normal-caliber duct segments that gives the cholangiogram its beaded appearance.

• Section 20.7: PSC complications and surveillance

  PSC is a premalignant condition with three associated cancers (cholangiocarcinoma, gallbladder cancer, and colorectal cancer in PSC-IBD), each with specific surveillance intervals and modalities.

• Section 20.8: IgG4 sclerosing cholangitis and overlap syndromes

  The fourth pillar of this chapter is the disease that mimics PSC but behaves differently, plus the two overlap syndromes that blur the AIH-PBC-PSC boundaries.

Podcast episodes

1. 01

   Sorting the Immune Liver Diseases and Autoimmune Hepatitis

   Episode one of the Autoimmune and Cholestatic Liver Diseases chapter builds the sorting framework for the three immune liver diseases and then works autoimmune hepatitis in depth. The organizing idea: pattern plus demographics plus antibodies place a patient into autoimmune hepatitis, primary biliary cholangitis, or primary sclerosing cholangitis within the first two sentences of the vignette. Autoimmune hepatitis is then the ANA and smooth-muscle-antibody interface hepatitis of the middle-aged woman with elevated IgG, confirmed on biopsy. The second half is treatment: steroid induction plus a steroid-sparing agent, the type one versus type two split, the simplified score, and why withdrawal is cautious because relapse is the rule.

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2. 02

   Primary Biliary Cholangitis

   Episode two works primary biliary cholangitis, the anti-mitochondrial-antibody cholestatic disease of the middle-aged woman, as a biochemical-target-driven problem. The diagnosis is usually made on labs alone, treatment starts with ursodeoxycholic acid for everyone, and escalation is driven by where the alkaline phosphatase and bilirubin sit at twelve months, because those numbers are the surrogate for survival. The second-line landscape changed when obeticholic acid left the US market, leaving elafibranor and seladelpar as the two approved PPAR-targeted agents that tend to improve rather than worsen the itch. The close is the stepped, mechanism-targeted pruritus algorithm from cholestyramine through rifampin, sertraline, naltrexone, and the emerging ileal transporter inhibitors.

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3. 03

   Primary Sclerosing Cholangitis and IgG4 Disease

   Episode three works primary sclerosing cholangitis, the multifocal stricturing disease of the man with ulcerative colitis, as a recognition-and-surveillance problem, then covers its steroid-responsive mimic. MRCP not serology makes the diagnosis, the alkaline phosphatase is normal in nearly half of patients at any moment, and because there is no proven medical therapy the work is surveillance for three cancers. The chapter closes on IgG4-related sclerosing cholangitis, the older man with painless jaundice and a sausage-shaped pancreas who responds dramatically to corticosteroids and must not go to a Whipple, plus the two overlap syndromes. Cancer thresholds, the dominant stricture workup, and the high-dose ursodeoxycholic acid harm signal run throughout.

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Key topics

• ·Sorting framework: target cell sets the biochemical pattern
• ·Demographics and IBD association across the three diseases
• ·Antibody panel and IgG profile as the discriminator
• ·Autoimmune hepatitis pathogenesis and two clinical faces
• ·Type one versus type two serologic subtypes
• ·Simplified scoring system and its blind spots
• ·Interface hepatitis and ancillary histology
• ·Steroid induction, azathioprine, and budesonide
• ·Remission endpoints and cautious withdrawal
• ·Clinical picture and pathogenesis of primary biliary cholangitis
• ·Lab-based diagnosis and when biopsy is needed
• ·Florid duct lesion and staging
• ·Biphasic natural history and prognostic scores
• ·Ursodeoxycholic acid mechanism and twelve-month response
• ·Second-line agents after obeticholic acid withdrawal
• ·Fat-soluble vitamins, bone, and the lipid profile
• ·Stepped mechanism-targeted pruritus algorithm
• ·Ileal bile acid transporter inhibitors
• ·Sclerosing cholangitis presentation and IBD association
• ·MRCP as the diagnostic test and role of ERCP
• ·Natural history and premalignant surveillance rationale
• ·Cholangiocarcinoma surveillance and CA 19-9
• ·Dominant stricture workup and brush cytology ceiling
• ·Gallbladder and colorectal cancer thresholds
• ·No proven therapy and high-dose UDCA harm
• ·IgG4-related sclerosing cholangitis and HISORt
• ·Autoimmune hepatitis overlap syndromes