19 ILD

Question 1

• What are the 2 types of lower resp diseases?

Answer 1

1. Obstructive —>contraction of airway —> obs of airflow—> ⬇️ FEV1 —> prob during inhalation
2. Restrictive —> lung size affected —> ⬇️ of lung volume —> prob during exhalation

Question 3

• What’s similar & what’s diff btwn obs and restrictive?

Answer 3

similar: syms like cough and shortness of breath
Diff: the abnormality mechanism ( place affected )

Question 4

• Where is the interstitium?

Answer 4

all over the lung btwn alveoli and capillaries from epical to base & lateral ventral sides

Question 5

• What is found in the interstitium?

Answer 5

An interstial space within a tissue or organ

Question 6

• In which tissue can we find the interstial space?

Answer 6

Specifically the tissue between the pulmonary alveoli and the bloods

Question 7

• What part of the lung can ILD affect?

it can affect all the lung or be patchy ( in specific site )

Answer 7

it can affect all the lung or be patchy ( in specific site )

Question 8

• What are the cells available in the interstitium?

Answer 8

1. macrophages
2. Lymphocytes
3. Mesenchymal: fibroblasts/myofibroblasts/smoothMC

Question 9

• What are the comp of the basement mem of ECM?

Answer 9

1. Collagen ( type 1 & 3 )
2. Elastin
3. Fibronectin
4. Proteoglycans

Question 10

• What are the components of the interstitium?

Answer 10

1. Fluid —> blood plasma
2. Cellular comp —> cells
3. Extracellular matrix comp —> basement mem comp

Question 11

• Is the interstitium normally visible radiographically?

Answer 11

No, only when there is disease bcz it causes edema / fibrosis / tumor —> increase its volume —> become visible

Question 12

• What is the interstitium?

Answer 12

the space between the air sacs (alveolus) and the capillary vessel and extends throughout the lungs

Question 13

• What are the main functions of the interstitium?

Answer 13

1. transportation system for nutrients and solutes
2. Regulation: barrier to plasma constituents passing from capillaries to alveolar spaces
3. Structural support for endo/epithelial cells & parenchymal cells
4. Mechanical support to the lung

Question 14

• What happens in the case of ⬆️ ECM comp deposition?

Answer 14

stiffness of the lung —> doesn’t expand easily

Question 15

• What are interstitial lung diseases?

Answer 15

a group of lung diseases affecting the interstitium that are charactized by inflammation or scarring or both

Question 16

• Where does the inflammation / scarring occur?

Answer 16

1. Interstitium
2. Alveoli
3. Bronchioles

Question 17

• How is the inflammation / scarring?

Answer 17

it can be patchy or diffused all over the lung

Question 18

• What are the results if inflammation &/or scarring?

Answer 18

1. Disrupts the tissue
2. ⬇️ in the ability of lungs to exchange gases
3. ⬇️ in lung volume

Question 19

Why does ILD’s progression vary from one type to another?

Answer 19

bcz of diff etiology and development rate

Question 20

• If you suspect ILD, what do you try to do?

Answer 20

1. X-ray
2. Blood tests
3. Spirometry

Question 21

• What are the adv of spirometry?

Answer 21

1. Very specific

2. Differential diagnosis btwn asthma / COPD /ILD

Question 22

• Are all ILDs chronic?

Answer 22

No, but majority are chronic some are driven by infection —> acute

Question 23

• What are the characteristics of chronic ILD?

Answer 23

1. Always there
2. Slowly develops
3. Irreversible damage

Question 24

• What are the causes & types of ILD?

Answer 24

1. Sys diseases: auto-immune / connective tissue disease
2. Occupational / environmental
3. Infection: interstitial pneumonitis /acute inter pneumonitis
4. Genetic diseases: hermansky-pudlak syndrome
5. Idiopathic diseases: pulmonary fibrosis (no known cause)

Question 25

• What are the environmental/occupational causes?

Answer 25

Diseases associated with a specific exposure to an agent known to damage the lungs

Question 26

• What are the agents that can cause damage to the lungs?

Answer 26

1. Asbestos 2. Tobacco smoke 3. Coal mines 4. Farmers 5. Meds like bleomycin / radiation

Question 27

• What is hermansky-pudlak syndrome?

Answer 27

It is albinism (ocalocatanous de-pigmentation) in addition to de-pigmentation, they may have platelet abnormality / ILD

Question 28

• What happens to coal miners’ lungs?

Answer 28

Normal lung —> black spots from coal dust —> prog massive fibrosis ( BLACK LUNG DISEASE / PNEUMOCONIOSIS )

Question 29

• What is honey comb lung?

Answer 29

if the lung appears as honeycomb in a CT scan or X-ray —> ILD

Question 30

• Why is honeycomb lung called like that?

Answer 30

bcz of the dense connective tissue —> which indicates fibrosis —> which is idiopathic

Question 31

• What happens in honeycomb lung?

Answer 31

Damage to alveoli —> ⬆️ alveolar size

Question 32

• What is the most common characteristic of ILD?

Answer 32

Fibrosis

Question 33

• What does the thickening of interstitial tissue result in?

Answer 33

Stiffness —> lung restrictions

Question 34

• What is the diff btwn lung biopsies in each case?

Answer 34

predominance of fibrosis: poor prognosis + advanced disease Predominance of inflammation: better prog + can respond to treatment if initiated early

Question 35

• What are the syms of ILD?

Answer 35

1. cough ( dry not productive ) 2. Breathlessness ( developing slowly ) 3. Tiredness & fatigue 4. Weight loss

Question 36

• What is used to diagnose ILD?

Answer 36

1. Chest x-ray 2. Pulmonary function testing (spirometry ) 3. Computed tomography ( CT scan ) 4. Lung biopsy ( bronchoscopy )

Question 37

• Why do we use spirometry?

Answer 37

to measure flow/volume loops

Question 38

• What does spirometry show?

Answer 38

1. ⬇️ RV 2. ⬇️ TLC 3. ⬇️ FVC 4. poor lung compliance 5. Normal or ⬆️ FEV1 / FVC ratio

Question 39

• How do they take lung biopsies?

Answer 39

by using an endoscope w/scissor like tool through the mouth / nose into the airways to take the sample