Interstitial Lung Disease Flashcards
What is interstitial lung disease?
Lung parenchymal disorders with common clinical, radiologic, physiologic, and pathologic features.
Hallmark: Involvement of interstitium
What is interstitial lung disease also known as?
Infiltrative Lung disease- b/c infiltration of cellular and noncellular elements within alveolar septa and alveoli
Diffuse Parenchymal Lung Disease
Restrictive lung disease- characterized by reduced total lung capacity in presence of a normal or reduced expiratory flow rate.
What are the types of interstitial lung disease we discussed?
Pneumoconioses (Coal Workers Pneumonconiosis/Silicosis/Asbestos/Berylliosis)
Sarcoidosis
Hypersensitivity Pneumonitis
Idiopathic Pulmonary Fibrosis
Collagen Vascular Disease (SLE/RA/Systemic Sclerosis)
What is Pneumoconioses?
Major causes?
Occurence in chronic interstitial lung disease?
Non-neoplastic lung diseases in response to inhalation of mineral dust/organic/ inorganic particulates/chemical fumes/vapors.
Major causes: Coal dust, silicosis, asbestos, beryllium
25% of chronic interstitial lung disease
On what does the development of pneumoconioses depend on?
- Amount of dust retained in the lung parenchyma and airways
- Size shape and buoyancy of particles (1-5 micrometers reach bifurcation of respiratory bronchioles and alveolar ducts/less than 0.5 microns reach alveoli and are phagocytosed by alveolar macrophages)
- Particle solubility and physiochemical reactivity
- Possible additional effects of other irritants (eg tabacco smoking)
What is Coal Worker’s Pneumoconiosis? Where is it found?
What types are there and how do they present?
Anthrocotic pigment- Found in Coal mines/Urban Centers/Tobacco smoke
- Pulmonary anthrocosis (mildest)- Asymptomatic, just anthrocotic pigment in interstitial compartment and lymph nodes
- Simple CWP- Characterized by fibrous opacities <1 cm in upper lobes and upper portions of lower lobes. Coal dust deposits adjacent to respiratory bronchioles
- Complicated CWP (severe)- Fibrous opacities > 1 cm with or without central necroses. Massive fibrosis (black lung disease).
What are complications of Complicated CWP?
Cor pulmonale
Caplan syndrome- CWP w/ rheumatoid nodules in lung
NO increased incidence of TB or cancer
What is Silicosis?
How does it work?
Presents how?
Complications?
Most common occupational disease worldwide. Caused by crystalline silicon dioxide (quartz) found in foundaries, sand blasting, and silica mines.
Quartz activates alveolar macrophages after engulfment–>cytokine release–>fibrogenesis
Presents with: Nodular opacities with concentric layers of collapse/Polarizable quartz particles/Egg shell calcific in hilar lymph nodes
Cor pulmonale, Caplan syndrome, Increased risk of TB and Cancer
How does Asbestos manifest?
Where does it deposit?
Sources?
Serpentine (chrysotile)=curly and flexible (less potential for damage as it cannot reach distal lung
or
Amphibole (crocidolie)=straight and rigid (more likely to cause damage by reaching distal parts of lung)
Deposited in resp. bronchioles, alveolar ducts, aveoli
Sources: insulation/roofing from 20 years ago/Demolition of old buildings
How does asbestos appear?
Clinical presentation?
Complications?
Ferruginous bodies (macrophage phagocytose asbestos fibers, coated with ferritin (iron and protein). Golden brown dumbell apperance (thickened at ends)
Clinically present: Benign pleural plaques/ciffuse interstitial fibrosis/Bronchogenic carcinoma (increased risk with smoking) 20 yrs after first exposure/Mesothelioma (no relation to smoking) 24-40 yrs after first exposure
Complications: Cor pulmonale/Caplan syndrome/NO INCREASE IN RISK FOR TB
What is Berylliosis?
How does it manifest?
Complications?
Beryllium, found in the nuclear and airspace industry
Presents as granulomatous inflammation (similar to TB and sarcoidosis)
Complications: Cor pulmonale and Caplan Syndrome
What is Sarcoidosis?
In what demographics does it present?
Disorder of immune regulation (unknown antigen w/ CD4 Th cells), causing multisystem granulomatous disease of unknown etiology. 25% of patients present with chronic interstitial lung disease.
African American 10x Whites
Female 2x Males
70% <40 years age
Nonsmokers
What tissues are involved in sarcoidosis?
Lab and Radiological findings?
Many.
Lung is the most common
Lymph nodes 2nd most common.
Increased ACE levels, used as marker of disease activity and response to steroids
Hypercalcemia (in 5%)
Cutaneous anergy (lack response to common skin antigens due to consumption of CD4 Th cells)
CXR: 1. Bilateral hilar adenopathy 2. Reticulonodular shadows in lungs
What is hypersensitivity pneumonitis?
Types?
Inhaled antigen producing granulomatous interstitia pneumonitis. Type III hypersensitivity.
1st exposure: IgG antibody in serum
2nd exposure:Antibody combine with inhaled immune complex antigens to form inflammation response in lung
Chronic exposure: Granulomatous formation (Type IV hypersensitivity)
Types:
Farmer’s Lung- Moldy hay- thermophilic actinomycetes bacteria (Saccharopolyspore rectivirgula)
Silo Filler’s disease- Inhalation of gases from plant material (oxides of nitrogen)
Byssinosis- Cotton/linen/help. Textile factory workers. “Monday Morning Blues”
