Respiratory Diseases 3

Question 1

What is an interstitium?

Answer 1

Contagious fluid-filled space exiting between structural barrier

Question 2

What is reticulation?

Answer 2

Results from thickening of interlobular or intralobular septa.

Question 3

What is subpleural reitculation?

Answer 3

Reticular interstitial pattern - changes and is typically in peripheral/ subpleural distribution

Question 4

What are fibroblastic foci?

Answer 4

Represent microscopic zones of acute lung injury and randomly distributed within areas of interstitial collagen deposition

Question 5

What happens when pulmonary diseases are restrictive?

Answer 5

Lungs are unable to expand, FEV, FVC are very low

Question 6

What is idiopathic pulmonary fibrosis?

Answer 6

A disease characterised by parenchymal remodelling and progressive scarring of the lung. More common in males

Question 7

What is emphysema?

Answer 7

Alveolar wall destruction and air trapping

Question 8

What is fibrosis?

Answer 8

Excessive scarring in lung due to aberrant repair. Thickening ans stiffening of tissue, matrix deposition (collagen fibres)
Difficulty breathing and getting O2 into blood stream

Question 9

What are the causes of idiopathic pulmonary fibrosis?

Answer 9

Combination of genetic and environmental factors e.g. infections i.e. bacteria/ fungi

Question 10

How do idiopathic lung diseases affect the interstitium?

Answer 10

Scarring makes it thicker and therefore harder for gas exchange

Question 11

What is the main site of injury for IPF?

Answer 11

Alveolar epithelial cells

Question 12

How do growth factors contribute to the developement of pulmonary fibrosis?

Answer 12

They recruit cells from the epithelium, this contributes to a pool of resident fibroblasts (these make matric proteins, an overproduce the ECM). These fibroblasts then turn into myofibroblasts from the help of growth factors leading to the development of pulmonary fibrosis

Question 13

What does the creation of fibroblasts and myofibroblast cause?

Answer 13

Scarring

Question 14

What is the name of the growth factor that activates collagen indirectly?

Answer 14

TGF-Beta

Question 15

What particular things can you look for when diagnosing IPF?

Answer 15

Restrictive pattern of spirometry or DLCO measurement. Buy symptoms resemble many other respiratory diseases

Question 16

What does DLCO stand for?

Answer 16

Diffusion capacity of carbon monoxide

Question 17

What are the key features of IPF that are detectable on a scan?

Answer 17

Look at periphery of lung see either subpleural reticulation or honeycombing using High resolution chest CT scan

Question 18

For IPF diagnosis what potential characteristics can you look for?

Answer 18

Dry intense cough on exertion, clubbing of fingernails which signifies low blood oxygen. And pattern of usual interstitial pneumonia

Question 19

What methods can be used to manage IPF?

Answer 19

Pirfenidone and Nintedanib - drugs treat side effects. Or oxygen therapy/ pulmonary rehabilitation. In severe cases, lung transplant/ palliative care

Question 20

How can we make improvements in the future to treat IPF?

Answer 20

Sensitive ILD biomarkers, Better curative treatments and better disease education

Question 21

How does COVID-19 infect the body?

Answer 21

Enters through the nose, and is covered in spike protein that binds to ACE2 receptor on target cell.

Spike protein needs to be cleaved to bind to a protease and uses host proteases e.g. TMPRSS2 on cell surface of target cell next to ACE2

Inside the domain, the virus is hidden

Question 22

Where are the Sars-Cov2 entry proteins expressed?

Answer 22

ACE2 and TMPRSS2 are expressed in the nose, oral mucosa and lung.
But mainly expressed in goblet and ciliate cells in nasal cavity and in the alveoli. So most expressed in nasal cavity

Question 23

Why is there increased infectivity of virus in the nose?

Answer 23

Many entry points in nasal cavity so more likely to get infected

Question 24

In which areas are the receptors expressed and what are the symptoms associate with these areas of expression?

Answer 24

Respiratory tract: Cough, pneumonia
GI tract: Diarrhoea, viral sheading
Brain: confusion, memory loss, agitation
Heart: palpitations, chest tightness, acute heart injury and heart failure

Question 25

Why are children less affected by COVID19?

Answer 25

Children have lower expression of ACE2 and TMPRSS2. Expression of those increases with age

Question 26

What are the long term effects of COVID19?

Answer 26

Can lead to fibrogenic changes in lung. Exacerbates pulmonary fibrosis. Fibrotic changes observed in patients recovered with Covid-19 as well as parenchymal remodelling, fibroblast proliferation, collagen deposition and fibrotic markers are upregulated