week 8 COPD and asthma Flashcards
(40 cards)
What does COPD stand for and what are the 3 main contributing conditions?
COPD = Chronic Obstructive Pulmonary Disease
Caused by:
Emphysema – destruction of lung tissue
Bronchiolitis – inflammation of small airways
Bronchitis – chronic mucus overproduction
What two main pathways can lead to the development of COPD?
In utero: restricted lung growth
Postnatal insults: e.g., cigarette smoke and other environmental toxins
How does elastin disruption contribute to COPD?
Elastin helps lung recoil
Its breakdown causes lung overexpansion and inefficiency
Loss of elastin = reduced recoil = lungs become larger and less efficient
How does vascular damage contribute to COPD symptoms?
loss of vessels → ↓ blood supply
Leads to hypoxia → bronchoconstriction
How does airway structure change in COPD compared to asthma?
In COPD, airways are disrupted and destroyed
In asthma, airways are remodelled
What is meant by COPD being a multimorbidity disease?
COPD often coexists with:
Cardiovascular disease
Cancer
Autoimmune disease
Chronic infections
Due to systemic inflammation, ageing, smoking, poor diet, inactivity
What role does systemic inflammation play in COPD?
Chronic inflammation affects multiple organs
Increases risk of cardiovascular events
Can contribute to death in COPD patients
What are the main drug classes used to manage COPD?
Bronchodilators: LAMAs and LABAs
Steroids: for eosinophilic inflammation
Vaccinations: reduce infection risk
Biologics: Anti-IL-5, IL-33, IL-4Rα
What is the role of muscarinic receptors in COPD pathophysiology?
Found in airway smooth muscle
Activation (mainly M3) → bronchoconstriction and mucus secretion
↑ ACh release in COPD due to increased cholinergic tone
What two drug targets help reduce bronchoconstriction in COPD?
Anticholinergics (e.g. atropine) → bronchodilation
β2 agonists (e.g. salbutamol) → bronchodilation
→ Often used in combination
Why is it hard to develop selective muscarinic receptor antagonists?
M2 and M3 receptors share similar binding pockets
Makes it hard to develop receptor-selective drugs
Inhaled delivery helps increase local action on M3 in lungs
Why are muscarinic antagonists often charged molecules?
Charged muscarinic antagonists (e.g. atropine, ipratropium) cannot cross the blood-brain barrier, reducing CNS side effects
What is the optimal combination for maximum bronchodilation in COPD?
Long-acting muscarinic antagonist (LAMA)
Long-acting β2 agonist (LABA)
What components make up mucosal immunity in the lungs?
Physical barriers: mucus, cilia
Immune cells: macrophages, neutrophils, dendritic cells
Antibodies: secretory IgA
Cytokine signalling: coordinates responses
How is immune cell function altered in COPD?
Macrophages: impaired pathogen clearance
Neutrophils: over-recruited, release damaging enzymes
↓ Secretory IgA → ↓ pathogen neutralisation
List 4 ways mucosal immunity is impaired in COPD.
Damage to airway epithelium from chronic irritants
Reduced ciliary function → poor clearance
Mucus hypersecretion with altered composition
Disrupted epithelial tight junctions
What is oxidative stress and how does it affect COPD gene expression?
Caused by chronic smoke exposure
Leads to post-transcriptional modification
Disrupts protective gene expression
Lungs remain in a constant state of inflammation
Why are steroids controversial in COPD treatment?
Effective in eosinophilic inflammation
But increase infection risk
Resistance common in neutrophilic COPD
May be overprescribed in non-responsive phenotypes
What are anti-IL-5 therapies and who benefits from them?
Biologics like Mepolizumab and Benralizumab
Target eosinophilic inflammation
Shown to reduce exacerbations in COPD patients with high eosinophil counts
What is the role of biologics in COPD treatment?
Target eosinophilic inflammation
Anti-IL-5 agents (e.g. Mepolizumab, Benralizumab) shown to reduce exacerbations in patients with high eosinophil counts
Why is inhaled corticosteroid (ICS) use controversial in COPD?
Benefits: reduces inflammation and exacerbations in eosinophilic patients
Problems:
Poor efficacy in neutrophilic COPD
Increased infection risk (e.g. pneumonia)
Steroid resistance is common
Overprescribed in steroid-unresponsive patients
What is asthma and how is it characterised?
Asthma is a heterogeneous disease marked by chronic airway inflammation, airway hyperresponsiveness, and airway remodelling, causing symptoms like wheeze, cough, and shortness of breath.
What happens to the airways during an asthma attack when an allergen is present?
The airways become hyperresponsive, leading to mucosal oedema and narrowing of the airway lumen.
How is airway obstruction in asthma measured?
FEV1 (forced expiratory volume in 1 second) is reduced,
Volume remains unchanged → due to smooth muscle constriction, not lung volume reduction.
