Restrictive Lung Disease Flashcards
What is restrictive lung disease?
What are the two types?
Air can’t get into lungs and they are restricted
Intrinsic- issue with parenchyma (alveoli)
Extrinsic- pleura, chest wall
What are the four cells found in lung parenchyma and their respective functions?
Alveolar T1 epithelial: gas exchange
Alveolar T2 epithelial: surfactant to reduce surface tension
Fibroblasts: produce ECM eg collagen
Alveolar macrophages: phagocytose
Where is the interstitial space found?
What does the interstitial space contain and what is its function?
Space between alveoli and capillaries- contains ECM and lymphatic vessels
Acts as a structural support for the lung for gas exchange- very thin
What are the three types of ILD (interstitial lung disease)
How does ILD present on history and examination?
Idiopathic, auto-immune or exposure related
Presentation: breathlessness, non productive cough, can’t exercise as well
Examination: inspiratory crackles, low oxygen saturation, digital clubbing
What is idiopathic pulmonary fibrosis?
What pulmonary function test decreases in this disease?
An idiopathic interstitial lung disease- progressive scarring
FVC: forced vital capacity
What is the pathophysiology behind IPF?
Why can exacerbations lead to death?
Injury to the epithelium leads to accumulation of ECM (more collagen) which forms remodelling and honeycomb cyst formation
The tissue does not heal or regenerate, so the lung function decreases more and more leading to death
What is hypersensitivity pneumonitis?
How does acute HP and chronic HP differ?
How does it present (3):
ILD caused by inhaling environmental antigens that cause an immune response
Acute- abrupt flu like symptoms- can resolve on its own
Chronic- can be fibrotic or non fibrotic (just inflammatory) over a long term low level exposure
Presents: inspiratory squeaks, IgG antibodies, high lymphocyte count
What is the pathophysiology behind HP?
Inflammatory response is started in reaction to the exposure to antigens
T helper cells and IgG antibodies differentiate
Lymphocytes accumulate and granulomas form
How are HP and SSc-ILD treated?
Remove antigen- animal, dust, feather etc
Corticosteroids
Immunosuppressants
Antifibrotics
What is Systemic sclerosis associated ILD?
How does it present?
Autoimmune connective tissue disorder causing progressive fibrosis affecting skin and variable organs
Can affect interstitial space
Presentation: digital clubbing, raynauds, sclerodactyly
What is the pathogenesis of SSc-ILD?
Tissue damage leads to the autoimmune response
This leads to fibrosis and inflammation on the interstitial space
