Respiratory Diseases 3 Flashcards
What is an interstitium?
Contagious fluid-filled space exiting between structural barrier
What is reticulation?
Results from thickening of interlobular or intralobular septa.
What is subpleural reitculation?
Reticular interstitial pattern - changes and is typically in peripheral/ subpleural distribution
What are fibroblastic foci?
Represent microscopic zones of acute lung injury and randomly distributed within areas of interstitial collagen deposition
What happens when pulmonary diseases are restrictive?
Lungs are unable to expand, FEV, FVC are very low
What is idiopathic pulmonary fibrosis?
A disease characterised by parenchymal remodelling and progressive scarring of the lung. More common in males
What is emphysema?
Alveolar wall destruction and air trapping
What is fibrosis?
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
What are the causes of idiopathic pulmonary fibrosis?
Combination of genetic and environmental factors e.g. infections i.e. bacteria/ fungi
How do idiopathic lung diseases affect the interstitium?
Scarring makes it thicker and therefore harder for gas exchange
What is the main site of injury for IPF?
Alveolar epithelial cells
How do growth factors contribute to the developement of pulmonary fibrosis?
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
What does the creation of fibroblasts and myofibroblast cause?
Scarring
What is the name of the growth factor that activates collagen indirectly?
TGF-Beta
What particular things can you look for when diagnosing IPF?
Restrictive pattern of spirometry or DLCO measurement. Buy symptoms resemble many other respiratory diseases
What does DLCO stand for?
Diffusion capacity of carbon monoxide
What are the key features of IPF that are detectable on a scan?
Look at periphery of lung see either subpleural reticulation or honeycombing using High resolution chest CT scan
For IPF diagnosis what potential characteristics can you look for?
Dry intense cough on exertion, clubbing of fingernails which signifies low blood oxygen. And pattern of usual interstitial pneumonia
What methods can be used to manage IPF?
Pirfenidone and Nintedanib - drugs treat side effects. Or oxygen therapy/ pulmonary rehabilitation. In severe cases, lung transplant/ palliative care
How can we make improvements in the future to treat IPF?
Sensitive ILD biomarkers, Better curative treatments and better disease education
How does COVID-19 infect the body?
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
Where are the Sars-Cov2 entry proteins expressed?
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
Why is there increased infectivity of virus in the nose?
Many entry points in nasal cavity so more likely to get infected
In which areas are the receptors expressed and what are the symptoms associate with these areas of expression?
Respiratory tract: Cough, pneumonia
GI tract: Diarrhoea, viral sheading
Brain: confusion, memory loss, agitation
Heart: palpitations, chest tightness, acute heart injury and heart failure
Why are children less affected by COVID19?
Children have lower expression of ACE2 and TMPRSS2. Expression of those increases with age
What are the long term effects of COVID19?
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
