Table 3—

Potential markers for the assessment of chronic obstructive pulmonary disease

Biological markersPhysiological markersSymptomatic markers
Expectorated cellular markers of inflammationMarkers of lung functionSymptoms
 Neutrophils, macrophages, Inspiratory capacity, DL,CO MRC Respiratory Questionnaire
  eosinophils, mast cells,Physiological tests of small airway obstructionBreathlessness
  lymphocytes Lung hyperinflation MRC Dyspnoea scale, Borg
Expectorated soluble markers of inflammationRate of decline of lung function  scale, BDI/TDI, UCSD
 TNF-α, IL-8, ECP, MPOExercise testing  dyspnoea scale
Expired gases 6-min walk testDisease-specific health status (health-
 NO, CO, H2O2Bronchial hyperreactivity related quality of life)
Expired air condensateSkeletal muscle function CRDQ, SGRQ, BPQ, PFSDQ,
 LTB4, cytokines, aldehydesLean body mass  PFSS, CCQ
Peripheral blood markersImagingGeneric health status
 Activated neutrophils, TNF-α, CT scan, PET, hyperpolarised SF-36, NHP, EQ-5D
  soluble TNF receptors, IL-6,  gas MRCognitive function
  IL-8, CRPExacerbations
Sputum protease/anti-protease levels Rate
 HNE, MMPs, α1-AT, SLPI, Type
  TIMPsQuantification of luminal airway mucus
EGF levels in sputumMeasures 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.