Lecture 17: Immunosuppression and Lung Diseases Flashcards
Name five lung infections
- Upper respiratory tract infections
- Acute bronchitis
- Chronic bronchitis
- Pneumonia
- Pleuritis
Describe Upper respiratory tract infections
affect approximately above the bronchi, common colds etc.
What is acute bronchitis?
a persistent (2-3 weeks but can be longer) infection (usually viral) in the lower respiratory tract.
What is chronic bronchitis?
Prolonged inflammation of the bronchial airways which leads to cough and mucus production.
What is pneumonia?
infection in the lung parenchyma (basically alveolar structures). Also consolidation
What is pleurtisis?
Inflammation of the pleural membranes. It can have many causes, including Pulmonary Embolism and viral or bacterial infections.
What is bronchiectasis?
Permanent dilation of the bronchi, often a sequel of insufficiently treated lung disease that develops into a pathological pattern of dilated bronchi, heightens susceptibility to further lung infections.
What are the effects of bronchiectasis?
- Permanent enlargement of the airways. Weakening of the elastic and muscular component of the bronchial walls.
- Excessive inflammatory response.
What are the clinical features of bronchiectasis?
- Chronic cough with significant mucus production
- Shortness of breath, coughing up blood and chest pains and wheezing
- Frequent lung infection
What causes bronchiectasis?
- Cystic fibtosis
- Lung infections: bacterial infections, TB, severe viral infections in childhood.
- Impaired host defences
- Immunosuppressive drugs
- Aspergillosis: hypersensitivity to the fungus Aspergillus fumigatus-increased inflammation
- Lung injury/lung obstruction
What is the vicious cycle theory?
The destructive effect of chronic airway infections
Describe the bronchiectasis vicious cycle
- Inflammation
- Bronchial drainage
- Mucociliary clearance
- Mucous hypersecretion
- Infection / microbial colonization
How is bronchiectasis diagnosed?
High resolution computed tomography (HRCT) scan must be performed, evidencing persistent dilation of the airways.
What are the feautures of a CT that show bronchiectasis?
- The internal diameter of a bronchus is >1.5 times (>150%) the diameter of the pulmonary artery (also known as the ‘signet ring’ pattern)
- Bronchial wall thickening (parallel tram lines)
- “Tree-in-bud” appearance
- Failure of bronchial tapering
What are the general management treatments for bronchiectasis?
- Vaccination
- Pulmonary rehabilitation
- Sputum surveillance
How do you treat mild bronchiectasis?
Airway clearamce techniques - daily physiotherapy
What is pulmonary rehabilitation?
- exercise training to improve lung function
- breathing techniques to reduce shortness of breath
- education on medication management
How do you treat moderate/ persistant symptoms for bronchiectasis?
- Antiinflammatory therapy: inhaled corticosteroids
- Antibiotic therapy - macrolides
- Airway clearance techniques - regular physiotherapy with adjuctive devices/ hypersmolar agents
How do you treat severe symptoms for bronchiectasis?
- Therapy in advanced disease: long term oxygen therapy, surgery
- Antiniotic therapy: Macrolides/ inhlaed antibiotics
- Antiinflammatory therapy: inhaled corticosteroids
- Airway clearance techniques: regular physiotherapy with adjuctive devices/ hupersmolar agents
What is inflammation in bronchiectasis dominated by?
By neutrophils that, when activated, release neutrophil serine proteases, including neutrophil elastase
How are neutrophil serine proteases activated?
Activated during neutrophil maturation in the bone marrow by dipeptidyl peptidase 1 (DPP-1; also known as cathepsin C) by removing the N-terminal dipeptide; this allows active enzymes to be packaged into granules before the release of neutrophils into the circulation.
What is Brensocatib (INS1007)?
Oral, selective, competitive, and reversible inhibitor of DPP-1 that has been shown to inhibit neutrophil serine protease activity in the blood of healthy volunteers.