Flashcards in Pulmonary Pathology II Deck (43):
What is the change in the FEV1/FVC in obstructive airway disease?
FEV1 decreases while FVC is largely unchanged. Thus, the ratio will DECREASE
What is the change in FEV1/FVC in restrictive airway disease?
FEV1 remains normal while the TLC decreases, hence decreasing the FVC. The ratio can be normal or in some cases, increased.
What are some examples of obstructive airway diseases?
- Chronic bronchitis
- Foreign body
What are some examples of restrictive airway diseases?
- Due to chest wall disorders (polio, obesity, pleural disease, kyphoscoliosis)
- Interstitial / infiltrative diseases (ARDS, dust diseases, interstitial fibrosis)
Intermittent and reversible airway obstruction
- Chronic bronchial inflammation with eosinophils
- Bronchial smooth muscle hypertrophy hyper-reactivity
- Increased mucus production
What is the pathogenesis of atopic asthma?
Immune Mediated. Type I hypersensitivity reaction. Involving Ig E bound to mast cells
• Begins in childhood, triggered by environmental allergens (dust, pollen etc.)
What is the pathogenesis of non-atopic asthma?
Non-immune triggering mechanisms (e.g. respiratory viruses, air pollutants like ozone)
• Hyperirritable bronchial tree; virus induced inflammation of the respiratory mucosa lowers the threshold of subepithelial vagal receptors to irritants
What is the main drug that can induce asthma?
What is occupational asthma?
Asthma develops after repeated exposure to inciding agent - ranges from fumes, to dust to organic agents
What is the cellular mechanism of asthma?
Th2 will produce IL-3/5 which is chemotactic for
eosinophils - IL-4 will lead to the promotion of B cells
to produce IgE
What are some susceptibility genes of asthma?
- ADAM 33- 20q
- Chromosome 5q
Persistent hyperinflated lungs
What can be seen in asthma mucus under the microscope?
What can be seen on microscopy of asthma after the degranulation of granulocytes?
Charcot Leyden Crystals
What is the difference between bronchi and bronchioles?
Bronchi have mucus glands and cartilage while bronchioles will have neither
What is the clinical definition of chronic bronchitis?
Persistent productive cough for at least three consecutive months in at least two consecutive years
What are some of the risks for chronic bronchitis?
- Urban dwellers, smog-ridden cities
- Most common in middle aged men
What are the morphological changes with chronic bronchitis?
- Hypertrophy of mucus secreting glands
- Goblet cell metaplasia
- Fibrosis (bronchiolitis obliterans)
What is the Reid Index?
The Reid index measures the gland to wall ratio (normally glands are 40% of wall thickness as measured from epithelial basement membrane to cartilage) - this will be higher in chronic bronchitis
What are the complications of chronic bronchitis?
Cor pulmonale with cardiac failure
How does cor pulmonale result from chronic bronchitis?
Hypoxia of the lung will lead to vasoconstriction in the
lungs which will increase BP - cor pulmonale
How does bronchogenic carcinoma result from chronic bronchitis?
Squamous metaplasia can occur to better handle
the wear and tear - possible leading into cancer from the metaplasia
Destruction of walls of airspaces distal to terminal bronchioles, leading to permanent abnormal
enlargement of air spaces.
What does Centriacinar (Centrilobular) emphysema affect and who does it often affect?
• Upper lobes
• Respiratory bronchioles
• Male smokers
• Often associated with chronic bronchitis
• Coal-workers pneumoconiosis
What does Panacinar emphysema affect and what mutation is most often associated with it?
• Lower lobes
• Whole acinus
• Alpha1-antitrypsin deficiency
What does Distal acinar (Paraseptal) emphysema affect
• Distal acinus - "grocery bag"
• Along pleura and lobular septa
• Adjacent to areas of fibrosis, scarring, atelectasis
What is a major complication of Distal acinar emphysema?
Pneumothorax in young adults
What does Irregular emphysema affect?
• Acini irregularly involved
• Associated with scarring/healed inflammatory lesions
What is the pathogenesis of emphysema?
Mild chronic inflammation, i.e. macrophages, CD8+ T lymphocytes, and neutrophils
Why does Alpha1-antitrypsin deficiency cause emphysema?
Alpha1-antitrypsin2 inadequacy causes a
functional deficiency which leads to increased elastase activity in the neutrophils which contributes to increased tissue damage
Where is Alpha1-antitrypsin encoded?
Pi locus of chromosome 14
Buzz word for the appearance of chronic bronchitis
Buzz word for the appearance of emphysema
Permanent dilatation of bronchi and bronchioles caused by destruction of the muscle and elastic tissue caused by chronic necrotizing inflammation.
What are some of the causes of bronchiectasis?
• Obstruction (tumor, foreign bodies)
• Infection (TB, Aspergillus)
• Cystic fibrosis
• Kartagener’s syndrome
• Immunodeficiency states
What is the pathogenesis of bronchiectasis?
Obstruction of the airways leads to impaired clearing mechanisms which causes the pooling of excretions distal to the obstruction. This culminates with inflammation of the airway with necrosis and fibrosis and finally dilatation
Why are cystic fibrosis patients at increased risk of bronchiectasis?
Primary defect in Chloride transport causing accumulation of viscous secretions obstructing the airways which causes increased susceptibility to repeated infections, and wide spread damage to the airway walls
- Caused by primary ciliary dyskinesia
- Autosomal-recessive with variable penetrance
- Absence/ shortening of dynein arms
What is associated with Kartagener Syndrome?
Centriacinar emphysema association
Panacinar emphysema association
Alpha 1 antitypsin deficiency
What is the general feature of emphysema?
Destruction and dilatation of acini