Potential markers for the assessment of chronic obstructive pulmonary disease
| Biological markers | Physiological markers | Symptomatic markers |
| Expectorated cellular markers of inflammation | Markers of lung function | Symptoms |
| Neutrophils, macrophages, | Inspiratory capacity, DL,CO | MRC Respiratory Questionnaire |
| eosinophils, mast cells, | Physiological tests of small airway obstruction | Breathlessness |
| lymphocytes | Lung hyperinflation | MRC Dyspnoea scale, Borg |
| Expectorated soluble markers of inflammation | Rate of decline of lung function | scale, BDI/TDI, UCSD |
| TNF-α, IL-8, ECP, MPO | Exercise testing | dyspnoea scale |
| Expired gases | 6-min walk test | Disease-specific health status (health- |
| NO, CO, H2O2 | Bronchial hyperreactivity | related quality of life) |
| Expired air condensate | Skeletal muscle function | CRDQ, SGRQ, BPQ, PFSDQ, |
| LTB4, cytokines, aldehydes | Lean body mass | PFSS, CCQ |
| Peripheral blood markers | Imaging | Generic health status |
| Activated neutrophils, TNF-α, | CT scan, PET, hyperpolarised | SF-36, NHP, EQ-5D |
| soluble TNF receptors, IL-6, | gas MR | Cognitive function |
| IL-8, CRP | Exacerbations | |
| Sputum protease/anti-protease levels | Rate | |
| HNE, MMPs, α1-AT, SLPI, | Type | |
| TIMPs | Quantification of luminal airway mucus | |
| EGF levels in sputum | Measures of pulmonary hypertension | |
| Urine markers | ||
| Markers of matrix degradation, | ||
| e.g. desmosine |
TNF-α: tumour necrosis factor-α; IL: interleukin; ECP: eosinophilic cationic protein; MPO: myeloperoxidase; NO: nitric oxide; CO: carbon monoxide; H2O2: hydrogen peroxide; LTB4: leukotriene B4; CRP: C-reactive protein; HNE: human neutrophil elastase; MMPs: matrix metalloproteinases; α1-AT: α1-antitrypsin; SLPI: secretory leukocyte protease inhibitor; TIMPs: tissue inhibitors of matrix metalloproteinases; EGF: epidermal growth factor; DL,CO: diffusing capacity of the lung for carbon monoxide; CT: computed tomograpy; PET: positron emission tomography; MR: magnetic resonance; MRC: Medical Research Council; BDI/TDI: baseline and transition dyspnoea index; UCSD: University of California, San Diego; CRDQ: Chronic Respiratory Disease Questionnaire; SGRQ: St. George's Respiratory Questionnaire; BPQ: Breathing Problems Questionnaire; PFSDQ: Pulmonary Function Status & Dyspnoea Questionnaire; PFSS: Pulmonary Function Status Scale; CCQ: Clinical COPD Questionnaire; SF-36: Short Form-36; NHP: Nottingham Health Profile; EQ-5D: EuroQol 5D.