Week 5 - Pathology of Restrictive Lung Diseases Flashcards
How does restrictive lung disease affect you?
decreased compliance (stretchability) in lung
How is gas transfer impaired? (3)
- reduced gas transfer due to diffusion abnormality.
- ventilation-perfusion mismatch.
- high FVC/FEV1 ratios but low values due to less air to begin
What is the presentation of restrictive lung disease?
- abnormal CXR/CT - lung length shortened.
- Dyspnoea,
- type 1 resp failure,
- heart failure
What is DAD
individual has acute interstitial pneumonia. diffuse alveolar damage, also known as ARDS
What is the pathology of DAD?
protein rich fluid fills alveoli and causes inflammation and fibrosis, damaging it. Forms very solid lung.
What is the development of DAD associated with?
- major trauma,
- chemical injury toxic inhalation,
- circulatory shock,
- drugs,
- infection,
- autoimmune disease.
- can be idiopathic
What is sarcoidosis?
idiopathic. type IV hypersensitivity. causes non-caesiating granulomas, nearly always in lymph, and very commonly in lungs
What is the presentation and treatment of sarcoidosis?
young adult with abnormal CXR or CT, SoB and cough, erythema nodosum and acute arthralgia.
corticosteroid treatment
What is Hypersensitivity Pneumonitis?
a response to antigens, typically farmers lung, bacteria, fungi, chemicals, bird/animal proteins. causes type III and IV hypersensitivity reaction - inflammation around granuloma
What is the symptomatic presentation of Hypersensitivity Pneumonitis?
dry cough, chills, fever, wheeze, crackles, tachypnoea, myalgia
Where are hypersensitivity pneumonitis granulomas seen and why?
apex of lung as higher O2 tension and later lymph node drainage.
What is Usual interstitial pneumonitis and when may you see this condition?
progressive scarring of the lungs.
may be seen in connective tissue diseases, drugs, asbestos, viruses
how do you differentiate between sarcoidosis and hypersensitivity pneumonitis?
both produce non-cassiating granulomas. sarcoidosis is type IV hypersensitivity reaction while hypersensitivity pneumonitis is type III and IV.
What is type III vs type IV hypersensitivity reaction?
Type III involves immune complex formation - granuloma. Type IV involves lymphocyte accumulation
What is the histopathology of usual interstitial pneumonitis? (UIP)
Patchy interstitial chronic inflammation. type II pneumocytes proliferate, and so do muscular and angiogenesis. fibroblasts activity proliferate - more areas become fibrous
