Diffuse Interstitial Disease Flashcards
A group of chronic disorders characterized by inflammation and fibrosis of the pulmonary interstitial tissue
diffuse interstitial disease
Known collectively as restrictive lung disease
diffuse interstitial disease
What are diffuse interstitial diseases caused by?
Many causes, poorly understood
Diffuse interstitial diseases are responsible for about __% of __________ pulmonary diseases.
Diffuse interstitial diseases are responsible for about 15% of noninfectious pulmonary diseases.
What are some fibrosing diseases? (7)
- Idiopathic pulmonary fibrosis
- Nonspecific interstitial pneumonia
- Cryptogenic organizing pneumonia
- Pulmonary fibrosis associated with connective tissue diseases
- Pneumoconiosis
- Drug reactions
- Radiation pneumonitis
What is a granumlomatous disease?
tuberculosis
What are types of diffuse interstitial disease?
- fibrosing dz
- granulomatous dz
- pulmonary eosinophilia
What is the pathogenesis of interstitial fibrosis?
- endothelial damage and activation
- fibroblast migration and proliferation, basement membrane disruption
- angiogenesis and myofibroblast foci formulation
- pulmonary fibrosis
chronic process of pulmonary fibrosis or scarring due to unknown causes
idiopathic pulmonary fibrosis
What is idiopathic pulmonary fibrosis cause by?
Caused by recurrent inflammation and repair in susceptible persons
With IPF, what is the cause the susceptible persons?
hereditary
What does IPF result in?
decreased lung compliance
What will IPF show with spirometry
decreased lung volume
What is IPF associated with?
- pulmonary HTN
- right HF
Does IPF occur abruptly or insidiously?
insidiously
What are the initial symptoms of IPF?
gradually increasing dyspnea on exertion and dry cough
What are the later symptoms of IPF?
- hypoxemia
- cyanosis
- clubbing
What is the typical age range for presentation with IPF?
40-70 yo
What are some general symptoms of IPF? (5)
- Shortness of breath
- Chronic dry, hacking coughing
- Fatigue and weakness
- Chest discomfort
- Loss of appetite and rapid weight loss
What are some CXR features of IPF?
- Reduced lung volume
- Reticular opacities
- Lower lobe and peripheral field predominance
- Honeycombing may be visible (fibrocystic appearance)
What imaging technique can you best se honeycombing?
better on CT versus xray
diseases that can involve the lung, resulting in different presentations including pulmonary interstitial fibrosis (other manifestations include vascular sclerosis, pneumonia, and bronchiolitis)
autoimmune connective tissue diseases
What are autoimmune connective tissue diseases associated with?
- pulmonary hypertension
- right HF
What are the causes of autoimmune connective tissues diseases? (3)
- Rheumatoid arthritis
- Systemic sclerosis (scleroderma)
- Lupus erythematosus
What percent of patients is rheumatoid arthritis the cause of autoimmune connective tissue diseases?
30-40%
Lung fibrosis in response to inhaled particles and aerosols
pneumoconiosis
With pneumoconiosis, ____________ ingest particles, die and release ________ contents and cytokines causing _______ without clearing ________ stimulus.
With pneumoconiosis, macrophages ingest particles, die and release lysosomal contents and cytokines causing fibrosis without clearing inflammatory stimulus.
What size are particles that are most likely to reach terminal alveoli?
1-5 microns
Pneumoconiosis has a similar pathology as which condition?
IPF
What are the causes of pneumoconiosis?
- mineral dust
- organic dust
- chemical fumes
What are some examples of mineral dust?
- coal
- silica
- asbestos
- iron oxide
What are organic dusts also associated with?
- hypersensitivity pneumonitis
- asthma
What are some examples of hypersensitivity pneumonitis causes?
- moldy hay
- bird droppings
What are examples of asthma causes?
- cotton
- flax
- hemp
- red cedar dust
What are some examples of chemical fumes?
- nitrous oxide
- sulfur dioxide
- ammonia
- benzene
- insecticides
What describes when certain drugs may be associated with acute and chronic alterations in respiratory structure and function?
drug-induced pulmonary disease
Drug-induced pulmonary disease has similar process as what condition?
IPF
What are some drugs that can cause drug-induced pulmonary disease? (6)
- bleomycin
- methotrexate
- amiodarone
- nitrofurantoin
- aspirin
- beta antagonists
What are 2 examples of granulomatous diseases?
- sarcoidosis
- hypersensitivity pneumonitis
a firm nodule resulting from chronic inflammation, often with a fibrous capsule
granuloma
What does a granuloma contain?
-macrophages
-lymphocytes
-plasma cells
-multinucleated giant cells
(all of these are associated with chronic inflammation)
Granulomas may contain ______ organisms and may have central ______.
Granulomas may contain infectious organisms and may have central necrosis.
What organism is caseating associated with specifically?
mycobacterium
What are examples of infectious causes of granulomatous diseases?
- bacteria
- fungi
- parasites
What are examples of noninfectious causes of granulomatous diseases?
- sarcoidosis
- hypersensitivity pneumonitis
An immunologically-mediated systemic disease of unknown cause characterized by non-caseating granulomas in many tissues and organs
sarcoidosis
What organs and tissues are most commonly affected by sarcoidosis?
- lungs
- LN/spleen
- eyes
- skin
How do you differentiate sarcoidosis from infectious causes?
biopsy will show an absence of microbes
What are CXR findings of sarcoidosis?
- bilateral hilar lymph node enlargement
- milia-size and larger granulomas that may cavitate
What percentage of sarcoidosis cases will you see bilateral hilar lymph node enlargement?
90% of cases
What may the granulomas in the lung initiate?
initiate interstitial fibrosis and pulmonary edema
What are some other signs of sarcoidosis?
- skin granulomas
- eye granulomas
immunologically-mediated inflammatory lung disorders caused by intense, usually prolonged exposure to inhaled animal, microbial, and some chemical antigens
hypersensitivity pneumonitis
What does hypersensitivity pneumonitis causes diffuse inflammation of and what can that result in?
Causes diffuse inflammation of interstitial lung, terminal bronchioli, and alveoli, can result in fibrosis
What does hypersensitivity pneumonitis require?
Requires abnormal sensitivity or heightened reactivity to the antigen = susceptible individuals
What are the 2 primary types of hypersensitivity reactions that cause hypersensitivity pneumonitis?
- type 3 (immune complex)
- type 4 (delayed hypersensitivity)
Acute attacks, which follow inhalation of antigenic dust in sensitized patients
hypersensitivity pneumonitis
With hypersensitivity pneumonitis, what are there recurring episodes of?
- fever
- dyspnea
- cough
- leukocytosis
with hypersensitivity pneumonitis, when do symptoms usually appear?
usually appear 4-6 hours after exposure
What may hypersensitivity pneumonitis progress to?
may progress to:
- respiratory failure
- dyspnea
- cyanosis
- decrease in total lung capacity and compliance
How can hypersensitivity pneumonitis be prevented?
Can be prevented by removal of the stimulus, if recognized early
What are the common sensitizing agents for hypersensitivity pneumonitis?
Common sensitizing agents include:
- organic dust with bacterial spores
- fungi
- animal proteins
- bacterial products
results from exposure to dusts generated from harvested humid, warm hay that permits the rapid proliferation of the spores of thermophilic actinomycetes
Farmer’s lung
What are the spores associated with Farmer’s lung?
thermophilic actinomycetes
provoked by proteins from serum, excreta, or feathers of birds
bird breeder’s lung/bird fancier’s disease
caused by thermophilic bacteria in heated water reservoirs
Humidifier or air-conditioner lung
What are CXR findings for hypersensitivity pneumonitis?
diffuse and nodular infiltrates
Several pulmonary disorders characterized by an infiltration of eosinophils into alveoli, resulting in intraseptal inflammation, fibrosis
pulmonary eosinophilia
What does pulmonary eosinophilia result in?
- intraseptal inflammation
- fibrosis
What is the cause of pulmonary eosinophilia?
frequently idiopathic
Assessment of diffuse interstitial disease
- History and physical examination
- Spirometry
- CXR or CT
- Oximetry, arterial blood gas, acid-base balance
- Endoscopic bronchial biopsy
- Laboratory assessment for autoimmune diseases (rheumatoid arthritis, lupus erythematosus, scleroderma, sarcoidosis)
What are symptoms of diffuse interstitial disease?
- dyspnea
- tachypnea
What are signs of diffuse interstitial disease?
- End-inspiratory crackles (without wheezing or other evidence of airway obstruction)
- Cyanosis
- Increased blood CO2 (hypercapnia) and reduced O2 (hypoxia)
- Reduced lung volume (FVC, TLC) and compliance (FEV1) by spirometry
What are CXR findings for diffuse interstitial disease?
CXR shows bilateral small nodules, irregular lines, ground-glass shadows
What does spirometry show with diffuse interstitial disease?
- Reduced lung volume (FVC, TLC)
- Reduced compliance (FEV1)
What does diffuse interstitial disease frequently result in?
Frequently results in:
- secondary pulmonary hypertension
- cor pulmonale
Why are end-stage diffuse interstitial diseases hard to differentiate?
hard to differentiate because they result in similar scarring and destruction of the lung (called end-stage lung or honeycomb lung)
