14. Restrictive Interstitial Lung Disease - Cox

• interstitial lung disease (ILD) - fibrotic thickening pulmonary interstitium

  • main problem - gas exchange issue
  • causing chronic dyspnea (SOB)
• Causes of interstitial lung disease

  • progressive lung tissue scarring via fibrosis and inflammation
• Interstitial lung disease (ILD) - same with diffuse parenchymal lung disease

  • Affects parenchyma with diffuse periacinar septal infiltrates
• ILD - syndrome - 3C

  • cough
  • clubbing of fingers
  • cracking
• ILD - traction bronchiectasis = dilated bronchi
• ILD - there is thickening with interstitium

  • interstitial fibrosis will impair gas exchange -- cause capillary damage
  • reduce DLCO
  • V/Q mismatch
• IPF (interstitial pulmonary fibrosis) - radiology

  • pattern - usual interstitial pneumonia
  • ** traction bronchiectasis - 2nd fibrotic mechanical stretching
  • differs from bronchiectasis due to inflammation
  • honeycombing

  
• usual interstitial pneumonia (UIP) pattern

  • patchy dense fibrosis
  • heterogeneity
  • honeycombing - enlarge airspaces surrounded by fibrosis
  • bronchiolar type epithelium lining cysts
• Honeycombing: enlarged airspaces surrounded by fibrosis

  • Bronchiolar type epithelium lining cysts
• IPF/UIP can lead to pulmonary hypertension --> cor pulmonale
• Non-specific interstitial pneumonia (NSIP) - there is no?-- compared to IPF 


  honeycombing
• NSIP vs IPF?

  NSIP has better prognosis
• 2 subtype of NSIP

  • fibrotic type - common + poor prognosis
  • cellular type - less common + better prognosis
  • response to treatment better
• NSIP pattern

  • temporal + spatial homogeneity - uniform thickening of alveolar wall
• NSIP - no sign of hyaline membrane due to diffuse alveolar damage (DAD)
• Cryptogenic organizing pneumonia (COP) - 2nd to organizing pneumonia

  • due to the repair process following alveolar injury
• COP/OP pathology

  • has fibroblastic plug (granulation tissue) -- referred to as masson bodies
  • obstruct airspaces
  • patchy inflammation - with thickened alveolar septa
• COP - has no trigger

  • its idiopathic
• Which IIP is the only acute?

  Acute interstitial pneumonitis (AIP)
• AIP (initial stage) similar features to ARDS

  • ground glass
  • traction bronchiectasis
  • air space consolidation
• AIP (initial stage) similar features to ARDS

  • ground glass
  • traction bronchiectasis
  • air space consolidation
  • ** characterized by DAD
  • acute phase has hyaline membrane
• AIP - has no pre-disposing factors unlike ARDS
• Respiratory Bronchiolitis present in all?

  smokers
• Respiratory Bronchiolitis - what is accumulated in airways an airspaces?

  smoker's macrophages - pigmented due to phagocytizing particles in smoke
• desquamative interstitial pneumonia (DIP)

  • alveolar filling due to smoker's macrophages
  • there is no alveolar epithelial desquamation (shedding)
  • thicken of alveolar septa

  
• Pulmonary Langerhans cell histiocytosis (PLCH)

  • identified in young adults
  • associated with smokers
• Pulmonary Langerhans cell histiocytosis (PLCH)

  • Langerhans cells can proliferate and form granulomas
• Pulmonary Langerhans cell histiocytosis (PLCH)

  1. Langerhans form granuloma
  2. destruction of bronchiolar walls
  3. formation of cyst
  4. cyst rupture
  5. spontaneous pneumothorax
• Pulmonary Langerhans cell histiocytosis (PLCH) can lead to pneumothorax due to cyst rupture
• Sarcoidosis - noninfectious granulomatous inflammation
• Sarcoidosis - can lead to atelectasis - why?

  • localized bronchial stenosis
  • mass effect (compressive obstruction)
• Sarcoidosis - clinical features

  • hypercalcemia
  • hypercalciuria
  • increase 1 alpha hydroxylase by granuloma macrophages
  • increase ACE levels
• Sarcoidosis - airway have cobblestone appearance - turbulence air

  
• Sarcoidosis can lead to pulmonary hypertension due to vascular compression

  • leading to cor pulmonale
• Hypersensitivity pneumonitis (noninfectious granuloma inflammation)

  • delayed allergic reaction - Th 1 cell and IgG driven
  • re-exposure trigger reaction
• Hypersensitive pneumonitis - progressive stage

  • interstitial fibrosis
  • honeycombing
  • Obliterative bronchiolitis - lead to luminal stenosis and fibrosis
• Eosinophilic lung diseases

  • excess infiltration of eosinophil within interstitium or alveoli

  
• Acute eosinophilic pneumonia (AEP)

  • acute hypersensitivity reaction to unidentified inhaled antigen
  • history of smoking
• Acute eosinophilic pneumonia (AEP)

  • eosinophilic infiltration and degranulation will cause lung inflammation and damage
  • leading to DAD --> ARDS
• Chronic eosinophilic pneumonia (CEP)

  • non-smokers
  • triad
  • pulmonary symptoms
  • abnormal chest imaging
  • increase eosinophils