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COPD phenotype description using principal components analysis.

Roy K, Smith J, Kolsum U, Borrill Z, Vestbo J, Singh D - Respir. Res. (2009)

Bottom Line: These results were confirmed by linear regression multivariate analyses which showed strong associations between the variables within components 1 and 2.Unrelated components of disease were identified, including neutrophilic airway inflammation which was associated with systemic inflammation, and sputum eosinophils which were related to increased Fe(NO).We confirm dissociation between airway inflammation and lung function in this cohort of patients.

View Article: PubMed Central - HTML - PubMed

Affiliation: University of Manchester, North West Lung Research Centre, University Hospital of South Manchester Foundation Trust, Manchester, UK. keyaroy2003@yahoo.co.uk

ABSTRACT

Background: Airway inflammation in COPD can be measured using biomarkers such as induced sputum and Fe(NO). This study set out to explore the heterogeneity of COPD using biomarkers of airway and systemic inflammation and pulmonary function by principal components analysis (PCA).

Subjects and methods: In 127 COPD patients (mean FEV1 61%), pulmonary function, Fe(NO), plasma CRP and TNF-alpha, sputum differential cell counts and sputum IL8 (pg/ml) were measured. Principal components analysis as well as multivariate analysis was performed.

Results: PCA identified four main components (% variance): (1) sputum neutrophil cell count and supernatant IL8 and plasma TNF-alpha (20.2%), (2) Sputum eosinophils % and Fe(NO) (18.2%), (3) Bronchodilator reversibility, FEV1 and IC (15.1%) and (4) CRP (11.4%). These results were confirmed by linear regression multivariate analyses which showed strong associations between the variables within components 1 and 2.

Conclusion: COPD is a multi dimensional disease. Unrelated components of disease were identified, including neutrophilic airway inflammation which was associated with systemic inflammation, and sputum eosinophils which were related to increased Fe(NO). We confirm dissociation between airway inflammation and lung function in this cohort of patients.

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Related in: MedlinePlus

Flow chart showing the total number of patients who were able to perform all measurements and those who were unable to complete certain measurements.
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Figure 1: Flow chart showing the total number of patients who were able to perform all measurements and those who were unable to complete certain measurements.

Mentions: Figure 1 shows that of the 127 patients, 10 patients could not perform FeNO adequately, 21 patients did not have blood taken for analysis, and 92 produced adequate sputum for analysis. There was no difference in pulmonary function or blood biomarker measurements between the patients who could and could not perform these measurements. All patients were included in the analysis, with 70 patients having a complete dataset with all variables. The post bronchodilator FEV1 range for these COPD patients was 17.9 to 79.6%. 98 of the 127 patients had moderate COPD (GOLD stage II), while 22 had severe disease (GOLD stage III) and 4 very severe disease (GOLD stage IV).


COPD phenotype description using principal components analysis.

Roy K, Smith J, Kolsum U, Borrill Z, Vestbo J, Singh D - Respir. Res. (2009)

Flow chart showing the total number of patients who were able to perform all measurements and those who were unable to complete certain measurements.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2698901&req=5

Figure 1: Flow chart showing the total number of patients who were able to perform all measurements and those who were unable to complete certain measurements.
Mentions: Figure 1 shows that of the 127 patients, 10 patients could not perform FeNO adequately, 21 patients did not have blood taken for analysis, and 92 produced adequate sputum for analysis. There was no difference in pulmonary function or blood biomarker measurements between the patients who could and could not perform these measurements. All patients were included in the analysis, with 70 patients having a complete dataset with all variables. The post bronchodilator FEV1 range for these COPD patients was 17.9 to 79.6%. 98 of the 127 patients had moderate COPD (GOLD stage II), while 22 had severe disease (GOLD stage III) and 4 very severe disease (GOLD stage IV).

Bottom Line: These results were confirmed by linear regression multivariate analyses which showed strong associations between the variables within components 1 and 2.Unrelated components of disease were identified, including neutrophilic airway inflammation which was associated with systemic inflammation, and sputum eosinophils which were related to increased Fe(NO).We confirm dissociation between airway inflammation and lung function in this cohort of patients.

View Article: PubMed Central - HTML - PubMed

Affiliation: University of Manchester, North West Lung Research Centre, University Hospital of South Manchester Foundation Trust, Manchester, UK. keyaroy2003@yahoo.co.uk

ABSTRACT

Background: Airway inflammation in COPD can be measured using biomarkers such as induced sputum and Fe(NO). This study set out to explore the heterogeneity of COPD using biomarkers of airway and systemic inflammation and pulmonary function by principal components analysis (PCA).

Subjects and methods: In 127 COPD patients (mean FEV1 61%), pulmonary function, Fe(NO), plasma CRP and TNF-alpha, sputum differential cell counts and sputum IL8 (pg/ml) were measured. Principal components analysis as well as multivariate analysis was performed.

Results: PCA identified four main components (% variance): (1) sputum neutrophil cell count and supernatant IL8 and plasma TNF-alpha (20.2%), (2) Sputum eosinophils % and Fe(NO) (18.2%), (3) Bronchodilator reversibility, FEV1 and IC (15.1%) and (4) CRP (11.4%). These results were confirmed by linear regression multivariate analyses which showed strong associations between the variables within components 1 and 2.

Conclusion: COPD is a multi dimensional disease. Unrelated components of disease were identified, including neutrophilic airway inflammation which was associated with systemic inflammation, and sputum eosinophils which were related to increased Fe(NO). We confirm dissociation between airway inflammation and lung function in this cohort of patients.

Show MeSH
Related in: MedlinePlus