357.2 🩺 國考版

357.2.1 高頻考點

357.2.1.1 AIH Subtypes

  • Type 1: ANA + ASMA (most common, all ages)
  • Type 2: anti-LKM-1, anti-LC1 (pediatric)
  • Type 3 (now Type 1 variant): anti-SLA/LP

357.2.1.2 AIH Diagnosis

  • ↑ IgG (specific)
  • ANA + ASMA (+/- anti-LKM-1)
  • Biopsy: interface hepatitis + plasma cells
  • Simplified IAIHG scoring

357.2.1.3 AIH Treatment

  • Prednisone 30-40 mg/d + azathioprine 1-2 mg/kg (standard)
  • Budesonide + AZA alternative
  • MMF, tacrolimus, rituximab for refractory
  • TPMT testing before azathioprine

357.2.1.4 PBC

  • F 9:1 (most female-predominant)
  • AMA 95% (anti-M2)
  • ALP + GGT elevated; ALT/AST less
  • Fatigue + pruritus + xanthomas + osteoporosis
  • Associated: Sjögren, autoimmune thyroid, celiac

357.2.1.5 PBC Treatment

  • UDCA 13-15 mg/kg lifelong (first-line)
  • For inadequate response:
    • Obeticholic acid (Ocaliva, FXR agonist, FDA 2016) — pruritus side effect
    • Bezafibrate / fenofibrate (off-label, evidence-based)
    • NEW 2024: elafibranor (Iqirvo) PPAR α/ÎŽ FDA June 2024
    • Seladelpar (Livdelzi) PPAR ÎŽ FDA August 2024

357.2.1.6 PSC

  • M > F (2:1)
  • UC association 75-90%
  • MRCP gold standard: “beading” multifocal strictures
  • pANCA (60-80%)
  • Cholangiocarcinoma risk 10-15% lifetime
  • CRC ↑ if UC concurrent

357.2.1.7 PSC Treatment

  • No effective medical therapy
  • UDCA modest (don’t use high-dose — harmful)
  • ERCP for dominant strictures
  • Cholangiocarcinoma surveillance (annual MRCP + CA 19-9)
  • Colon cancer surveillance if IBD
  • Liver transplant: end-stage or hilar cholangiocarcinoma (Mayo protocol)

357.2.1.8 Overlap Syndromes

  • AIH-PBC: steroids + UDCA
  • AIH-PSC: less common

357.2.1.10 Key Trials

  • POISE: obeticholic acid for PBC
  • ELATIVE: elafibranor for PBC (2024 FDA)
  • RESPONSE: seladelpar for PBC (2024 FDA)
  • UDCA-PSC: high-dose UDCA harmful in PSC

357.2.2 易混淆比范

Feature AIH PBC PSC
Sex F > M (3-4:1) F >> M (9:1) M > F (2:1)
Antibodies ANA, ASMA, LKM-1 AMA 95% pANCA
LFT pattern Hepatocellular Cholestatic Cholestatic
Histology Interface hepatitis + plasma cells Florid duct lesion + granulomas Onion-skin periductal fibrosis
IBD association None None UC 75-90%
Imaging Normal Normal early MRCP beading
Treatment Prednisone + AZA UDCA + obeticholic / elafibranor / seladelpar No medical; ERCP; transplant
Cancer risk HCC if cirrhosis HCC if cirrhosis Cholangiocarcinoma 10-15%

357.2.3 Special Topics

357.2.3.1 PBC Pruritus Management

  • Cholestyramine first
  • Rifampin
  • Naltrexone
  • Gabapentin
  • Sertraline
  • Refractory: UVB phototherapy, plasmapheresis, liver transplant

357.2.3.2 Refractory AIH

  • MMF
  • Tacrolimus
  • Rituximab
  • Combination

357.2.3.3 Anti-Mitochondrial Antibody (AMA) Subtype

  • M2 (dihydrolipoyl transacetylase) — PBC-specific
  • M1, M3, etc. less specific

357.2.3.4 Anti-Sp100 + Anti-gp210

  • PBC-specific ANA patterns
  • Worse prognosis