Table 1

Summary of main findings in different biomarker ECLIPSE studies

Type of biomarkerMain findings
Cellular biomarkers
 Sputum neutrophils3.5% variability at 1-year follow-up3
 Sputum neutrophilsWeak/absent association with FEV1%, SGRQ, emphysema, systemic inflammatory markers, exacerbation frequency or lung function decline3
 Circulating WBCAssociated with persistent systemic inflammation,4 frequent exacerbations5 and mortality6
Blood protein biomarkers
 FibrinogenSignificantly associated with symptoms, exercise capacity, exacerbation rate and BODE index.6 10 Currently undergoing a regulatory qualification process11
 CC16Weakly associated with lung function decline, emphysema and depression12–15
 SP-DWeak association with COPD exacerbations5 16; sensitive to treatment with oral and inhaled corticosteroids16
 CCL18 (PARC)Increased risk of cardiovascular hospitalisation or mortality17
 sRAGELower circulating sRAGE levels are associated with emphysema severity, and genetic polymorphisms in the AGER locus are associated with circulating sRAGE levels22
 Inflammome*Patients with persistent systemic inflammation (16%) had higher mortality and exacerbation rate than patients without inflammation (30%).4 Systemic inflammation was also associated with heart disease, hypertension and diabetes18
 AdipokinesLeptin and adiponectin levels were (+) and (−) related to CRP, respectively; BMI and gender were the strongest determinants of both adipokines20
 Vitamin DLow levels of vitamin D were related to emphysema, 6MWD, airways reactivity and CC-16 levels21
Sputum transcriptomics
 Airflow limitation277 genes associated with the severity of airflow limitation (GOLD stage)48
 Emphysema198 genes associated with the presence of emphysema48
 Blood biomarkersSNPs affecting circulating CC16 protein levels were significantly associated with sputum mRNA expression of SCGB1A1, the CC16 coding gene on chromosome 1147
 COPD susceptibilityAn integrative genomics approach located potential functional variants in two genes located within a COPD GWAS locus on chromosome 15 (CHRNA5 and IREB2) and one locus in the HLA-C region on chromosome 651
Serum metabolomics
 Serum profileResults indicate that52 53: (1) there is increased protein turnover in all COPD patients; (2) increased protein degradation in individuals with emphysema and cachexia
Exhaled breath condensate
 pHLower pH in COPD and smoking controls, but not related to FEV1 or sputum leucocyte counts and not responsive to steroid treatment54
 Adenosine/purinesIncreased concentrations in COPD patients and adenosine levels correlated with FEV155
  • *Inflammome: combined panel of six inflammatory markers in serum (WBC, CRP, interleukin 6, interleukin 8, tumour necrosis factor α and fibrinogen).

  • BMI, body mass index; COPD, chronic obstructive pulmonary disease; CRP, C-reactive protein; FEV1, forced expiratory volume in 1 s; FFMI, fat-free mass index; GWAS, genome-wide association studies; 6MWD, 6-minute walking distance; PARC, pulmonary and activation-regulated chemokine; SGRQ, St George's Respiratory Questionnaire; SNP, single nucleotide polymorphism; sRAGE, soluble receptor for advanced glycation end products; WBC, white blood cell.