Interstitial lung disease Flashcards Preview

Respiriatory: Airway Disease > Interstitial lung disease > Flashcards

Flashcards in Interstitial lung disease Deck (37)
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1
Q

What comprise the pulmonary interstitium?

A
  • Alveolar lining cells type 1 and 2

* Thin elastin-rich connective component containing capillary blood vessels

2
Q

What takes place across alveolar walls?

A

Gas exchange

3
Q

What are the features of alveolar walls?

A
  • Elastic structure (allowing for ventilation)

* Very thin (allowing gas exchange)

4
Q

What is the early stage of interstitial lung disease?

A

Alveolitis - injury with inflammatory cell infiltration

5
Q

What is associated with acute ILD?

A

Adult respiratory distress syndrome (ARDS)

6
Q

What is the late stage of ILD?

A

Fibrosis

7
Q

What do the clinical effects of ILD occur due to?

A
  • Hypoxia (respiratory failure)

* Cardiac failure

8
Q

Is fibrosis in ILD diffuse or localised?

A

Diffuse fibrosis – localised scarring won’t cause many problems

9
Q

What are causes of ILD?

A
  • Environmental (minerals, drugs, radiation
  • Post-ARDS (post-infective episode)
  • Hypersensitivity (mouldy hay, avian proteins)
  • Unknown (idiopathic)
  • Connective tissue diseases – SLE, rheumatoid
  • Idiopathic pulmonary fibrosis (IPF)
10
Q

How is ILD diagnosed?

A

Based on clinical features often with biopsy

11
Q

What are biopsy methods in ILD?

A

Transbronchial biopsy – special forceps used in bronchoscopy (good for picking up granulomas in the case of TB, sarcoid etc)
Thoracoscopic biopsy – more invasive but more reliable and generates far more tissue

12
Q

What is lymphocytic interstitial pneumonia?

A

A cause of ILD

13
Q

What is lymphocytic interstitial pneumonia associated with?

A

HIV

14
Q

What are causes of chronic ILD?

A
  • Idiopathic pulmonary fibrosis (IPF)
  • Sarcoidosis
  • Extrinsic allergic alveolitis (hypersensitivity pneumonitis)
  • Pneumoconiosis
  • Connective tissue diseases
15
Q

What is idiopathic pulmonary fibrosis (IPF) also known as?

A

Cryptogenic fibrosing alveolitis (CFA) or Usual interstitial pneumonia (UIP)

16
Q

What is IPF?

A

Progressive interstitial fibrosis of unknown cause

17
Q

What are the clinical features of IPF?

A
  • Variable associated inflammation

* Finger clubbing

18
Q

What is the pathology of IPF?

A
  • Subpleural and basal fibrosis
  • Inflammatory component variable
  • Terminally lung structure replaced by dilated spaces surrounded by fibrous walls (honeycomb lung)
19
Q

What is extrinsic allergic alveolitis also known as?

A

Hypersensitivity pneumonitis

20
Q

What is EAA?

A

A chronic inflammatory disease affecting the small airways and interstitium with an allergic origin (type III and IV hypersensitivity mixed allergic response)

21
Q

What is EAA characterised by?

A

Occasional granulomas

22
Q

What allergic responses are involved in EAA?

A

Mixed allergic response

  • Type III - antibody mediated
  • Type IV - T cell mediated, granuloma formation
23
Q

What are causes of EAA?

A
  • Thermophilic bacteria – Farmers lung
  • Avian proteins – Bird fanciers lung
  • Fungi – Malt workers lung
24
Q

What is used to diagnose EAA?

A
  • Precipitins (antibodies) often detectable in serum

* Biopsy

25
Q

What is sarcoidosis?

A

Multisystem granulomatous disorder of unknown cause

26
Q

What are clinical features of sarcoidosis?

A
  • Granuloma formation
  • Uveitis (inflammation of iris)
  • Erythema nodosum
  • Lymphadenopathy
  • Hypercalcaemia
27
Q

How is sarcoidosis diagnosed?

A
  • CXR - often see bilateral hilar lymphadenopathy
  • Restrictive defect in PFT
  • Transbronchial biopsy - granuloma
28
Q

TB and sarcoidosis both result in granuloma formation. How are the 2 distinguishable from one another?

A

TB involves necrosis, sarcoidosis does not

29
Q

What is a common side effect of chronic sarcoidosis?

A

Fibrosis due to chronic inflammation

30
Q

In what ways can connective tissue diseases affect the respiratory system?

A
  • Interstitial fibrosis (milder than IPF)
  • Pleural effusions
  • Rheumatoid nodules
31
Q

What is a rheumatoid nodule?

A

A necrotic nodule found in the lung - characteristic of rheumatoid

32
Q

What is pneumoconiosis?

A

Lung disease caused by mineral dust exposure

33
Q

What are examples of pneumoconiosis?

A
  • Asbestosis
  • Coal workers lung
  • Silicosis
34
Q

What does pneumoconiosis depend on?

A
  • Particle size (1-5μm)
  • Reactivity of particle
  • Clearance of particle
  • Host response
35
Q

What is asbestos?

A

A silicate

36
Q

What shape are asbestos fibres?

A
  • Serpentine (curved) asbestos fibres relatively safe

* Straight (amphibole) asbestos highly dangerous

37
Q

What are the effects of asbestos exposure?

A
  • Parietal pleural plaques (only caused by asbestos exposure)
  • Interstitial fibrosis (asbestosis)
  • Bronchial carcinoma
  • Mesothelioma