Restrictive (interstitial lung disease)

Question 1

What type of disease are interstitial diseases?

Answer 1

Inflammatory

Question 2

What is the interstitium of the lung

Answer 2

Between the alveolar cell wall and the basement membrane of the endothelial cell from the capillary

Question 3

What is normal interstitium like? Why?

Answer 3

Usaully no/very little space, alveolar cell and endothelial cells are stuck tightly together for optimum gas diffusion.

Question 4

What are the unifying feature of interstitial lung disease?

Answer 4

Causes restrictive lung defect
Occurs within the interstitial part of lung
Most occur throughout the whole lung

Question 5

Why do they get a restrictive reading?

Answer 5

Because the inflammation stiffens the lung and so lung is unable to expand as much and therefore also isn’t able to get as much air in, despite there still being the same amount of elastic fibres.

Question 6

Is there loss of elastic tissue in interstitial lung disease?

Answer 6

No

Question 7

How can you think about interstitial lung disease?

Answer 7

A rope tied to an elastic band, the elastic fibres are still there and able to expand and contract, however the rope (inflammation and fibrous tissue)is the restricting part.

Question 8

What readings for FEV1/FVC

Answer 8

Both reduced, but the ratio can sometimes be increased

Question 9

Clinical symptoms of interstitial lung disease?

Answer 9

Usually not many and can often only be discovered due to a scan (CXR/CT) for other conditions.

Otherwise will present later with SOB on exertion, then later stages present with SOB at rest.

Can have Type 1 respiratory failure and heart failure

Question 10

How is it discovered?

Answer 10

CXR/CT

Question 11

Xray on max inhalation Emphysema vs interstitial

Answer 11

Emphysema = large lung volume visable (long and thin), interstitial = reduced lung volume (length) - just can’t expand as lungs are so stiff

Question 12

What impact can chronic inflammatory responses lead to?

Answer 12

fibrosis of the lung

Question 13

The more likely the process of ………., the more likely to lead to end-stage honeycomb?

Answer 13

fibrosis

Question 14

What is DAD/? or DADS?

Answer 14

Diffuse alveolar damage or Diffuse Alveolar Damage Syndrome, its the pathological process for acute interstitial lung disease

Question 15

What can cause DAD?

Answer 15

Any form of acute injury to the alveolar.

Can be due to:
Major trauma
Chemical injury/toxic inhalation
Circulatory shock
Drugs
Infection (inc. viruses inc. SARS Cov1 and SARSCov2)
Autoimmune disease
Radiation

And can be Idiopathic (unknown cause)

Question 16

what happens in Diffuse Alveolar Damage (DAD) - timescale?

Answer 16

first day or 2 = MASSES of swelling (oedema) from plasma of capillaries

days 3-6 hyaline membranes - plasma proteins line the alveoli.

day 7/8+ - interstitial inflammation is maximized, with interstitial fibrosis not far behind

Question 17

What causes Hyaline membranes?

Answer 17

Plasma proteins lining alveolar

Question 18

What does hyaline membrane look like?

Answer 18

pink and clear lining

Question 19

What is the result of DADS?

Answer 19

A chaotic repair process that results in severe lung damage and extensive fibrosis

Question 20

Why do DAD patients often die with type 1 respiratory failure?

Answer 20

Because the Oedema can be severe and widespread.

Question 21

What type of chronic interstitial lung disease is sarcoidosis?

Answer 21

Granulomatosis

Question 22

What is sarcoidosis?

Answer 22

The most common chronic interstitial lung disease (still relatively rare)

Type 4 hypersensitivity reaction (T cell hypersensitivity) causing epitheliod and giant cell granulomas which do not have necrosis. They are found throughout the body, prevalently in the lung interstitium.

Question 23

How do we distinguish sarcoidosis to eg TB

Answer 23

sardoidosis granulomas gearally do not have necrosis, whereas TB/ other infective granulomas do

Question 24

Who is usually affected by sarcoidosis and where is it most prevelant?

Answer 24

Most prevalent in temperate climates (including the UK).

Prevalence highest in African ethnicity living in a temperate climate.
Commonly affects young adults, females more than males.

Question 25

Main organs involved in sarcoidosis?

Answer 25

Lymph nodes (almost 100% cases)
Lung (>90)
Spleen (75)
Liver (70)
Skin/Eyes/Skeletal muscle (50)
Bone marrow (20)
Salivary Glands (up to 50% cases)

Question 26

How is sarcoidosis diagnosed?

Answer 26

Often clinically, often doesn’t need a pathological sample

Question 27

What type of interstitial inflammation is hypersensitivity pneumonitis?

Answer 27

Granulomatous

Question 28

What are the main antigens causing Hypersensitivity pneumonitis?

Answer 28

Organic molecules/antigens

Bird/Animal proteins  (Faeces/bloom)
Thermophilic actinomycetes (micropolyspora faeni/Thermoactinoyces vulgaris)
Fungi - Aspergillus spp
Chemicals
Others

Question 29

What causes Hypersensitivity pneumonitis?

Answer 29

Type 3 and Type 4 inflammatory responses.

Type 4 leads to production of granulomas
Type 3 leads to chronic interstitial inflammation and Pneumonitis!

Question 30

Presentation of Hypersensitivity Pneumonitis

Answer 30

Variable dependant on extent on reactivity and dose.

Can present like an acute pneumonia, but more often chronic presentationof gradually deteriorating pulmonary function.

History is KEY - possible exposure to anything in the air they breathe

Question 31

What hypersensitivity reaction is HP?

Answer 31

Types 3 and 4

Question 32

Where does HP begin and why?

Answer 32

Centriacinar region as it is inhaled antigens, so this is the area to be affected by the antigen first.

Question 33

Difference sarcoidosis and HP

Answer 33

Inflammatory process around granulomas in Hypersensitivity Pneumonitis (due to type 3 hypersensitivity in addition to type 4), whereas in sarcoidosis you just get the granuloma.

Question 34

Where in lung and why?

Answer 34

Tends to be upper zones as clearance mechanisms in upper parts of the lungs are not as efficient as in the lower parts, also inhaled antigens generally en up more in upper parts of lungs.

Question 35

What is IPF?

Answer 35

Ideopathic pulmonary fibrosis

Question 36

What type of chronic response is IPF?

Answer 36

Inflammatory

Question 37

What is usual interstitial pneumonitis and what is it caused by?

Answer 37

The pathological process in the lungs when the patient has Idiopathic Pulmonary Fibrosis = Usual interstitial Pneumonitis.

Can be caused by drugs, viruses and asbestos

Question 38

Is biopsy necessary to confirm UIP?

Answer 38

No

Question 39

How long does it take acute vs chronic to get to end stage?

Answer 39

Acute Diffuse Alveolar Damage = can be days/weeks

Progressive disease = months/years

Question 40

UIP (Usual Interstitial Pneumonia) will usually end up with… and die of. Less common for…??

Answer 40

End stage honeycomb lung

Less common for Sarcoidosis, and Hypersensitivity Pneumonitis (to a lesser extent).

Question 41

What does UIP (Usual Interstitial Pneumonitis) look like under a microscope throughout the lung? Is there evidence of injury in UIP?

Answer 41

Chronic inflammation, lymphocytes and macrophages.
Type 2 pneumocyte hyperplasia.

Yes, evident to see damage to lung, both new and old injuries.

Question 42

Clinical presentation of UIP?

Answer 42

Dyspnoea, cough

Basal crackles, Cyanosis, Clubbing

Question 43

Where does IPS concentrate within the lung?

Answer 43

Posterior and basal parts

Question 44

Does fibrosis increase chance of getting lung cancers?

Answer 44

Yes

Question 45

Is there increased or decreased compliance in interstitial lung disease?

Answer 45

Decreased compliance

Question 46

Will there be a ventilation/perfusion imbalance?

Answer 46

yes