pathology of lung disease - restrictive Flashcards
when can fibrosis occur (post inflammation)
as a result of chronic inflammation (autoimmune disease, persistent injury, chronic infections etc.); abscess formation; certain acute inflammations
scar formation steps
- injury to tissue
- induces inflammation
- formation of vascularised granulation tissue
- deposition of extracellular matrix to form the scar
5 Rs of imflammation/repair
- recognition (of injurious agent)
- recruitment (of leukocytes)
- removal (of the agent)
- regulation (of the response)
- resolution/repair
5 causes of restrictive lung disease
primary lung fibrotic diseases/ILD; chest wall/pleura abnormalities; neuromuscular disease; bony abnormalities; obesity
what is restrictive lung disease
a group of disorders characterised by reduced lung expansion and reduction of total lung capacity
what is an interstitiual lung disease
a diverse group pf disorders characterised by inflammation and fibrosis that distorts the normal architecture of the lung
in ILDs why does the lung become stiff (reduced elasticity) and have a reduced gas transfer capability
thickening of the alveolar walls (with non-elastic, fibrotic components) results in reduced elasticity and impaired GE (further to travel)
6 types of ILDs
idopathic pulmonary fibrosis; occupation related; medication induces; hypersensitivity pneumonitis; autoimmune related; smoking related
examples of idiopathic interstitial pneumonia (not IPF)
non-specifici interstitual pneumonia; acute interstitiual pneumonia; cryptogenic organising pneumonia; desquamative interstitial pneumonia
what distribution does scarcoidosis occur in
bronchovascular
what is hypersensitivity pneumonitis (extrinsic allergic alveolitis)
chronic disease of the lungs resulting from inhalation of organic antigenic substances - local hypersensitivity reaction triggered due to pt having an abnormal sensitivty to causative agent
what is the classic cause of EAA/HP?
birds (bird fancier’s lung)
causes of EAA (8)
birds, hay, cotton production, air conditioners/hot tubs; vaping, cheese (cheese worker’s lung), house mold, metal-cutting fluid etc.
pathophysiology of HP/EEA
organic antigen identified by denritic cells -> immune complex mediated response (IgG antibody production) + cell mediated (sensitisation of helper T cells) -> increase in neutrophils, mast cells, macrophages CD8+ cells etc. -> numerous inflammatory outcomes (e.g. epithelial injury, tissue breakdown and collagen deposition, elastic fibre break down)
what are the 3 types of HP/EEA
acute; subacute; chronic
what is the triad of findings for subacute HP
- lymphoplasmocytic interstitial infilrate w bronhiolocemtric distribution on pathology
- organizing pneumonia
- poorly formed granulomas on pathology
histology of HP/EEA
peribronchial poorly formed granulomas; organising granulation tissue; may have fibrosis; inflammatory cells present
common professions to have occupational lung diseases
construction (esp asbestos); coal miner; bakers; roofers; electricians; plumbers
what is pneumoconiosis
a group of lung diseases caused by the lung’s reaction inhaling certain dusts - permanent alteration of lung structure due to the inhalation of mineral dust and the tissue reactions of the lung to its presence
what is the commonest pneumoconosis
silicosis (cement, sandblasters etc.)
brief pathophysiology of penumoconosis
fine dust particles escape the muco-cilliary escalator and are able to reach the alveoli/interstitium -> engulphed by pulmonary macorphages which promotes inflammation and release of fibrogenic cytokines -> worse in upper lobes (V/Q ratio)
brief pathophysiology of asbestosis
crystals are inhaled and then phagocytosed resulting in an inflammatory response which stimulates the release of proinflammaotry/fibrogenic mediators
what type of asbestos is more dangerous
Crocidolite asbestos (blue) - amphibole fibres
why is serpentine asbestos less dangerous
the fibres are “wavy” and so are more likely to be caught in the muco-cillary escalator
