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. 2020 Dec 1:15:3147-3158.
doi: 10.2147/COPD.S265674. eCollection 2020.

Clinical Features and C-Reactive Protein as Predictors of Bacterial Exacerbations of COPD

Nick A Francis  1 , David Gillespie  2 , Mandy Wootton  3 , Patrick White  4 , Janine Bates  2 , Jennifer Richards  3 , Hasse Melbye  5 , Kerenza Hood  2 , Christopher C Butler  6
Affiliations

Clinical Features and C-Reactive Protein as Predictors of Bacterial Exacerbations of COPD

Nick A Francis et al. Int J Chron Obstruct Pulmon Dis. .

Abstract

Introduction: Identifying predictors of bacterial and viral pathogens in sputum from patients with acute exacerbations of chronic obstructive pulmonary disease (COPD) may help direct management.

Methods: We used data from a trial evaluating a C-reactive protein (CRP) point of care guided approach to managing COPD exacerbations in primary care. We used regression analyses to identify baseline clinical features, including CRP value in those randomized to testing, associated with bacterial, viral or mixed infections, defined by the presence of bacterial and viral pathogens in sputum, detected by culture or polymerase chain reaction (PCR), respectively.

Results: Of 386 participants with baseline sputum samples, 79 (20.5%), 123 (31.9%), and 91 (23.6%) had bacterial, viral/atypical, and mixed bacterial/viral/atypical pathogens identified, respectively. Increasing sputum purulence assessed by color chart was associated with increased odds of finding bacterial and mixed (bacterial and viral/atypical) pathogens in sputum (area under the ROC curve (AUROC) for bacterial pathogens =0.739 (95% CI: 0.670, 0.808)). Elevated CRP was associated with increased odds of finding bacterial pathogens and mixed pathogens but did not significantly increase the AUROC for predicting bacterial pathogens over sputum color alone (AUROC for combination of sputum color and CRP = 0.776 (95% CI: 0.708, 0.843), p for comparison of models = 0.053). We found no association between the presence of sputum pathogens and other clinical or demographic features.

Conclusion: Sputum purulence was the best predictor of sputum bacterial pathogens and mixed bacterial viral/atypical pathogens in patients with COPD exacerbations in our study. Elevated CRP was associated with bacterial pathogens but did not add to the predictive value of sputum purulence.

Keywords: COPD; bacteria; exacerbation; infection; primary care; sputum.

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Conflict of interest statement

Nick A Francis reports grants from NIHR HTA, during the conduct of the study. David Gillespie reports grants from the National Institute for Health Research, during the conduct of the study. Janine Bates reports grants from NIHR HTA, during the conduct of the study. Kerenza Hood report grants from NIHR HTA, during the conduct of the study; and I am a member of three NIHR funding committees: HTA General Committee, HTA Funding Committee Policy Group and the Research Professors panel. Christopher C Butler reports grants from the National Institute for Health Research Health Technology Assessment Programme, during the conduct of the study. The authors report no other potential conflicts of interest for this work.

Figures

Figure 1
Figure 1
Bacterial (A) and viral/atypical (B) pathogens isolated from baseline sputum samples.
Figure 2
Figure 2
Association between sputum color and number of bacterial pathogens isolated.
Figure 3
Figure 3
CRP Category by type (bacterial, viral, mixed or none) of pathogen isolated.
See this image and copyright information in PMC

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References

    1. Anzueto A. Impact of exacerbations on COPD. Eur Respir Rev. 2010;19(116):113–118. doi:10.1183/09059180.00002610 - DOI - PMC - PubMed
    1. Bafadhel M, McKenna S, Terry S, et al. Acute Exacerbations of Chronic Obstructive Pulmonary Disease. Am J Respir Crit Care Med. 2011;184(6):662–671. doi:10.1164/rccm.201104-0597OC - DOI - PubMed
    1. Wilkinson TMA, Aris E, Bourne S, et al. A prospective, observational cohort study of the seasonal dynamics of airway pathogens in the aetiology of exacerbations in COPD. Thorax. 2017;72(10):919–927. doi:10.1136/thoraxjnl-2016-209023 - DOI - PMC - PubMed
    1. Donaldson GC, Seemungal T, Jeffries DJ, Wedzicha JA. Effect of temperature on lung function and symptoms in chronic obstructive pulmonary disease. Eur Respir J. 1999;13(4):844–849. doi:10.1034/j.1399-3003.1999.13d25.x - DOI - PubMed
    1. Anderson HR, Spix C, Medina S, et al. Air pollution and daily admissions for chronic obstructive pulmonary disease in 6 European cities: results from the APHEA project. Eur Respir J. 1997;10(5):1064–1071. doi:10.1183/09031936.97.10051064 - DOI - PubMed