Table 1.
Main differences between COPD and Asthma.
| COPD | Asthma | |
|---|---|---|
| Onset | Mid life | Early or Late onset |
| Risk factors | Smoking | Atopy, irritant exposures, smoking |
| Symptoms | Slowly progressive | Intermittent |
| (i) Breathlessness | On moderate/minimal effort | On exacerbations |
| (ii) Cough | Regularly | On exacerbations |
| Family history | May be present | May be present |
| FEV1/FVC ratio | <70% | <70% |
| FEV1% predicted | <80% | <80% |
| Bronchodilator response | Absent/present | Present |
| Inflammatory cells | Neutrophils | Eosinophils |
| Macrophages | Neutrophils | |
| CD8+ cells (Tc) | Mast cells | |
| CD4+ cells (Th2) | ||
| Structural changes | Airway smooth muscle + | Airway smooth muscle +++ |
| Peripheral airways | All airways | |
| Parenchymal destruction | No parenchymal involvement | |
| Epithelial metaplasia | Epithelial shedding | |
| Fibrosis++ (peribronchiolar) | Fibrosis + (subepithelial) | |
| Mucus secretion +++ | Mucus secretion + | |
| Steroid response | +/− | +++ |