1b Restrictive Lung Disease

Question 1

What is a restrictive lung disease?

Answer 1

When the expansion of the lungs is restricted

Lung volumes are small

Question 2

What are the two types of restrictive lung disease?

Answer 2

Intrinsic Lung Disease
Extrinsic Lung Disease

Question 3

What does intrinsic lung disease involve?

Answer 3

Alterations to the lung parenchyma = interstitial lung disease

Question 4

What does extrinsic lung disease involve?

Answer 4

Compression of the lungs / limiting expansion
- pleural
- chest wall
- neuromuscular = decreases the ability of the respiratory muscles to inflate / deflate the lungs

Question 5

What is the lung parenchyma?

Answer 5

The alveolar regions of the lung

Question 6

What are the four cellular components of the lung parenchyma?

Answer 6

1. Alveolar type 1 epithelial cell
2. Alveolar type 2 epithelial cell
3. Fibroblasts
4. Alveolar macrophages

Question 7

What is the interstitial space?

Answer 7

The space between the alveolar epithelium and the capillary endothelium - filled with collage and matrix which restricts the diffusion of oxygen into the lungs

Question 8

What does the interstitial space contain?

Answer 8

Lymphatic vessels, occasional fibroblasts and ECM

Question 9

What is the purpose of alveolar type 1 epithelial cells?

Answer 9

Gas exchange surface

Question 10

What is the purpose of alveolar type 2 epithelial cells?

Answer 10

They release a surfactant to reduce surface tension and are stem cells needed for repair

Question 11

What do fibroblasts do?

Answer 11

Produce ECM like collage type 1

Question 12

Which alveolar epithelial cell can differentiate?

Answer 12

Type 2 -> into type 1

Question 13

What is the purpose of alveolar macrophages?

Answer 13

Phagocytose foreign material, and release surfactantx

Question 14

Why is the interstitial space thin?

Answer 14

In order to facilitate gas exhange

Question 15

Which immune cell are closely associated with the lung epithelium?

Answer 15

Alveolar macrophages

Question 16

What characterises interstitial lung disease?

Answer 16

inflammation or fibrosis in the interstitial space

Question 17

What is the common history of a patient with Interstitial Lung Disease?

Answer 17

Progressive Breathless
Non-productive cough
Limitations in exercise tolerance
Occupational history

Question 18

What are the clinical examinations seen in patients with interstitial lung disease?

Answer 18

Low O2 saturations
Fine bilateral inspiratory crackle
Digital clubbing

Question 19

What is the 6 minute walk test?

Answer 19

make patients walk for 6 minutes and if they desaturate below 88% then this is a good marker of interstital lung disease

Question 20

What is the mainstay investigation into ILD?

Answer 20

High Resolution CT - look at the pattern of disease

Question 21

What are the two invasive tests which might be done for a patient with ILD?

Answer 21

1. Bronchoalveolar lavage - flood lungs with saline and see how much can / is removed
2. Surgical Lung Biospy

Question 22

Why does the compliance of the lung decrease in ILD?

Answer 22

Scarring makes the lung stiff

Question 23

What happens to Forced Vital Capacity in ILD?

Answer 23

decreases

Question 24

What happens to the diffusing capacity of lung for CO in IDL?

Answer 24

Decreases

Question 25

What happens to the FEV1/FVC ratio in ILD?

Answer 25

Normal or increased

Question 26

What type of pattern is seen on a HRCT in Interstitial pneumonia?

Answer 26

Honey comb

Question 27

What pattern is seen on a HRCT in organising pneumonia?

Answer 27

Consolidation = dense white

Question 28

What are the general principles of ILD management in Early Disease?

Answer 28

Pharmacological treatments Patient education Vaccination Smoking cessation Treatment of co-morbidities Pulmonary rehabilitation

Question 29

What are the general principles of ILD management in late disease?

Answer 29

Supplemental O2 Lung transplant Palliative Care

Question 30

What is idiopathic pulmonary fibrosis?

Answer 30

Progressive, scarring lung disease or unknown cause

Question 31

Which gender is idiopathic pulmonary fibrosis more common in?

Answer 31

Men

Question 32

What is the prognosis of Idiopathic pulmonary fibrosis?

Answer 32

poor, even lower survival rate than many cancers

Question 33

What are the three predisposing factors of IPF?

Answer 33

Genetic susceptibility Environmental triggers Cellular Ageing

Question 34

What is the mechanism of IPF?

Answer 34

Injury to the endothelial lining Aberrant fibroblast activity Excess accumulation of ECM Results in remodelling and honeycomb cyst formation

Question 35

What effect does remodelling have on the lung?

Answer 35

Honey comb cysts - make the lung less efficient at gas exchange

Question 36

What event initiates IPF?

Answer 36

Alveolar epithelial injury

Question 37

Describe the histopathological changes which are seen with IPF?

Answer 37

Microscopic honeycomb cysts Fibroblastic foci = proliferating myofibroblasts

Question 38

Where does IPF originate from?

Answer 38

The base / periphery of the lung and moves inwards

Question 39

What used to be the conventional therapy for IPF?

Answer 39

Immunosuppression

Question 40

What is the most useful treatment for IPF now?

Answer 40

Anti-fibrotics

Question 41

What are two anti-fibrotics?

Answer 41

Nintedanib and Pirfenidone

Question 42

What us hypersensitivity pneumonitis?

Answer 42

ILD caused by immune mediated response in susceptibile and sensitized individuals to inhaled environmental antigens

Question 43

What is involved in hypersensivity pneumonitis?

Answer 43

Involves small airways and parenchyma

Question 44

What are the two different types of hypersensitivity pneumonitis?

Answer 44

Acute HP and Chronic HP

Question 45

What is the difference between Acute and Chronic HP?

Answer 45

Acute = intermittent, high level exposure with abrupt symptom onset Chronic = long term, low level exposure, and non-fibrotic = purely inflammatory

Question 46

What drives the pathophysiology of hypersensitivity pneumonitis?

Answer 46

Immunological dysregulation - involves the innate and adaptive immune system

Question 47

What mediates the inflammatory response seen in HP?

Answer 47

T-Helper cells and antigen-specific IgG antibodies

Question 48

What does the immunological dysregulation of HP result in the formation of?

Answer 48

Accumulation of lymphocytes and formation of granulomas

Question 49

Why is the exposure history so important in the diagnosis of HP?

Answer 49

Antigen is not identified in about half the cases

Question 50

What can be heard in patients with HP?

Answer 50

Inspiratory ‘squeaks’ on auscultation - caused by the coexisting bronchiolitis

Question 51

What bronchoalveolar lavage lymphocyte count is a good indicator of HP?

Answer 51

>30%

Question 52

What does bronchiolocentric inflammation show on a HRCT

Answer 52

Ground glass nodules

Question 53

What is the treatment of HP?

Answer 53

- Complete removal of the antigen - Use corticosteriods - Immunsuppresants - if progressive and fibrotic, use Nintedanib = anti-fibrotic

Question 54

What is SSc associated ILD?

Answer 54

An autoimmune connective tissue disease characterised by dysregulation and progressive fibrosis that affects the skin, with variable internal organ involvment

Question 55

Who does SSc ILD effect?

Answer 55

Young, middle aged women

Question 56

What are the clinical features of SSc\?

Answer 56

Raynaud's Small Mouth Sclerodactyly Abnormal nail fold capillaroscopy Digital Ulcer Telengectasias - broken small blood vessels near the surface of the skin

Question 57

What is the difference between limited cutaneous SSc and Diffuse SSc?

Answer 57

Limited = only skin involvement up to elbows, diffuse = involves the whole body

Question 58

What is different about SSc compared to other ILD's?

Answer 58

SSc has a vascular component

Question 59

What HRCT is seen in SSc-ILD?

Answer 59

Non-specific interstitial pneumonia (NSIP) pattern is the most common pattern

Question 60

What determines which treatment is given for SSc-ILD?

Answer 60

Determined by disease extent on HRCT and lung function trajectory (monitor every 3 – 6 months)

Question 61

What are the management options for SSc-ILD?

Answer 61

orticosteroid use is controversial and risk of renal crisis with high doses (>10mg/day) Immunosuppressives – cyclophosphamide, mycophenolate mofetil (MMF)1 Progressive fibrotic phenotype– Nintedanib (antifibrotic)2