306.2 🩺 國考版

306.2.1 高頻考點

306.2.1.1 HP Common Antigens

  • Bird antigens (bird fancier’s, pigeon breeder’s)
  • Thermophilic actinomycetes (farmer’s lung, humidifier)
  • Hot tub MAC
  • Isocyanates
  • Specific occupations: maple, cheese, mushroom, etc.

306.2.1.2 HP BAL

  • Lymphocytosis ≥ 30%
  • CD4/CD8 < 1 (key vs sarcoid > 4)

306.2.1.3 HP HRCT

  • Acute: ground-glass + centrilobular nodules
  • Subacute: mosaic attenuation, air trapping (expiratory)
  • Chronic/fibrotic: upper-mid lung reticulation + traction bronchiectasis + honeycomb

306.2.1.4 HP Treatment

  • Antigen avoidance (most important)
  • Steroids for acute/subacute/severe
  • Nintedanib / pirfenidone for fibrotic HP (2020 ATS update)
  • Transplant for end-stage

306.2.1.5 Acute Eosinophilic Pneumonia (AEP)

  • Acute + smoking trigger
  • BAL eos > 25%
  • Peripheral eos absent initially
  • Dramatic steroid response (days)
  • Resolves completely

306.2.1.6 Chronic Eosinophilic Pneumonia (CEP)

  • Subacute weeks-months
  • Women, asthma association
  • “Photographic negative of pulmonary edema” HRCT
  • Steroid responsive; relapse 50%

306.2.1.7 ABPA

  • Asthma or CF
  • IgE > 1000
  • Central bronchiectasis (HRCT)
  • Itraconazole + steroids
  • Dupilumab for refractory (emerging)

306.2.1.8 EGPA (Churg-Strauss)

  • Asthma + eosinophilia + vasculitis
  • ANCA-associated (often)
  • Mepolizumab approved (2017)

306.2.1.9 Idiopathic HES

  • 1500 eos for 6 months + organ involvement

  • FIP1L1-PDGFRA → imatinib
  • Mepolizumab approved

306.2.2 易混淆比范

Disease Key Feature BAL Treatment
HP (non-fibrotic) Antigen + acute/subacute Lymphocytic CD4/CD8 < 1 Antigen avoidance + steroids
HP (fibrotic) Chronic + irreversible Fibrosis Antifibrotic + steroids
Sarcoidosis Non-caseating granulomas Lymphocytic CD4/CD8 > 4 Steroids ± IS
AEP Acute + smoking trigger Eos > 25% Steroids dramatic
CEP Subacute + asthma Eos + lymph Steroids long-term
ABPA Asthma/CF + IgE > 1000 Eos Itraconazole + steroids
EGPA Asthma + vasculitis Eos Steroid + IS / mepo
HES > 1500 eos chronic Eos Imatinib / mepo

306.2.3 Special Topics

306.2.3.1 CD4/CD8 in BAL

  • HP: CD4/CD8 < 1
  • Sarcoid: CD4/CD8 > 4 (often)
  • Useful distinguisher

306.2.3.2 Sarcoidosis vs HP

  • Both lymphocytic BAL
  • Sarcoid: non-caseating granulomas (well-formed)
  • HP: bronchiolocentric inflammation, less organized granulomas
  • ACE level not specific
  • CD4/CD8 key