352.3 🏥 內科專科考前版

352.3.1 Mechanistic Deep Dive

352.3.1.1 Celiac Immunology

  • Gluten → gliadin
  • HLA-DQ2/DQ8 presentation
  • T-cell mediated
  • TG2 (tissue transglutaminase) — autoantigen + crosslinks gliadin
  • Inflammatory cytokines + villous atrophy

352.3.1.2 Tight Junction in Celiac

  • Zonulin upregulation → increased permeability
  • Larazotide acetate target

352.3.2 Recent Trials & Updates

352.3.2.1 Latiglutenase

  • Combination glutenases
  • Phase 2-3 trials

352.3.2.2 Larazotide Acetate

  • Zonulin antagonist
  • Tight junction stabilizer
  • Mixed results

352.3.2.3 Cell-Based Therapies for Celiac

  • Investigational
  • Future direction

352.3.2.4 Rifaximin Re-Treatment for SIBO

  • Multiple courses can be effective

352.3.3 High-Yield Specialist Points

352.3.3.1 Celiac Screening Recommendations

  • T1DM
  • Family history
  • IgA deficiency
  • Autoimmune disease

352.3.3.2 GFD Compliance

  • Difficult lifestyle modification
  • Cross-contamination issues
  • Hidden gluten in many foods
  • Eat-out challenges
  • Dietitian + support groups helpful

352.3.3.4 Celiac + Pregnancy

  • Untreated celiac → infertility, miscarriage, IUGR
  • GFD improves
  • Folate supplementation important

352.3.3.5 Celiac in Children

  • Failure to thrive
  • ESPGHAN allows no-biopsy approach in select
  • Early diagnosis improves growth

352.3.3.6 SIBO + Diabetes

  • Diabetic enteropathy
  • Autonomic neuropathy
  • Common cause
  • Treat with rifaximin + prokinetics

352.3.3.7 SIBO + Scleroderma

  • Motility dysfunction
  • Treatment challenging
  • Repeated rifaximin courses

352.3.3.8 Methane vs Hydrogen Breath Tests

  • Methane SIBO: more associated with constipation
  • Methanogens (Methanobrevibacter smithii)
  • Treatment may include rifaximin + neomycin

352.3.3.9 Lactose Intolerance Severity

  • Primary deficiency lifelong
  • Secondary may recover (post-enteritis)
  • Yogurt with live cultures often tolerated

352.3.3.10 PERT Dosing

  • 25,000-75,000 units lipase per meal
  • 10,000-25,000 per snack
  • Adjust based on response

352.3.3.11 Whipple Disease Diagnosis

  • PCR for T. whipplei
  • PAS-positive macrophages
  • Multi-system: arthralgia + GI + neurologic + cardiac + ocular

352.3.3.12 Lymphangiectasia

  • Primary or secondary
  • Endoscopic with white villi
  • Treatment: low-fat MCT diet, octreotide (limited)

352.3.4 Pearls

  • Celiac: anti-tTG IgA + total IgA + biopsy
  • HLA-DQ2/DQ8 required (but not sufficient)
  • Lifelong GFD standard
  • Dermatitis herpetiformis pathognomonic
  • Refractory celiac type II → EATL risk
  • Whipple: PAS+ + ceftriaxone → TMP-SMX 1 year
  • SIBO: hydrogen breath test + rifaximin
  • Lactose intolerance: hydrogen breath test + restriction
  • Pancreatic insufficiency: fecal elastase + PERT