Pathophysiology & clinical aspects of COPD Flashcards
Define COPD.
Chronic, mostly irreversible, obstructive airway changes
Which 2 conditions comprise COPD?
Chronic bronchitis
Emphysema
COPD can overlap with which other respiratory condition to cause which condition?
Overlap with asthma to result in asthma-COPD overlap syndrome (ACOS)
List 2 causes of COPD.
Smoking
a1-antitrypsin deficiency
What percentage of smokers develop clinically significant COPD?
10-20%
Do most people with COPD have chronic bronchitis, emphysema, or both?
Both – most individuals will have chronic bronchitis and emphysema to varying degrees – they are on a spectrum of the two conditions
List 3 defining features of chronic bronchitis, and what this causes.
Inflammation in the larger airways (bronchus, larger bronchioles)
Mucus gland hypertrophy & hyperplasia
Hypersecretion of mucus
This causes a chronic, productive cough
List 2 defining features of emphysema, and what this causes.
Alveolar wall destruction
Air space enlargement (reduced gas exchange surface area)
This causes shortness of breath
Which 3 cells are dominant in chronic bronchitis?
Macrophages
CD8+ T-lymphocytes
Neutrophils
How does the elasticity of the alveolar wall change in emphysema?
There is a loss of elasticity
What are the 2 types of emphysema?
Centriacinar emphysema
Panacinar emphysema
Which type of emphysema is caused by smoking?
Centriacinar emphysema
Which type of emphysema is caused by a1-antitrypsin deficiency?
Panacinar emphysema
In emphysema, which 3 factors cause alveolar wall destruction?
Oxidative stress
Inflammatory cells & mediators
Protease-anti-protease imbalance
How does smoking cause oxidative stress and therefore damage to alveolar walls?
ROS (free radicals) are generated by cigarette smoke and released from inflammatory cells such as macrophages and neutrophils. These cause tissue damage (e.g. cell apoptosis) and further inflammation
