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Neutrophil elastase as a biomarker for bacterial infection in COPD.pdf (833.12 kB)

Neutrophil elastase as a biomarker for bacterial infection in COPD.

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posted on 2019-08-21, 10:37 authored by SJ Thulborn, V Mistry, CE Brightling, KL Moffitt, D Ribeiro, M Bafadhel
BACKGROUND: Chronic obstructive pulmonary disease (COPD) is predominantly associated with neutrophilic inflammation. Active neutrophil elastase (NE) is a serine proteinase, secreted by neutrophils, in response to inflammation and pathogen invasion. We sought to investigate if NE could be used as a biomarker for bacterial infection in patients with COPD. METHODS: NE was quantified using ProteaseTag® Active NE Immunoassay (ProAxsis, Belfast) from the sputum of COPD subjects at stable state, exacerbation and 2 weeks post treatment visit. RESULTS: NE was measured in 90 samples from 30 COPD subjects (18 males) with a mean (range) age of 65 (45-81) years and mean (SD) FEV1 of 47% (18). The geometric mean (95%CI) of NE at stable state was 2454 ng/mL (1460 to 4125 ng/mL). There was a significant increase in NE levels at an exacerbation (p = 0.003), and NE levels were higher in a bacterial-associated exacerbation (NE log difference 3.873, 95% CI of log difference 1.396 to 10.740, p = 0.011). NE was an accurate predictor of a bacteria-associated exacerbation (area (95%CI) under the receiver operator characteristic curve 0.812 (0.657 to 0.968). CONCLUSION: NE is elevated during exacerbations of COPD. NE may be a viable biomarker for distinguishing a bacterial exacerbation in patients with COPD. TRIAL REGISTRATION: Leicestershire, Northamptonshire and Rutland ethics committee (reference number: 07/H0406/157).


This work was funded by the Medical Research Council, the Wellcome Trust & Academy of Medical Sciences and the Oxfordshire Health Services Research Committee. MB was funded by a National Institute for Health Research Fellowship. The ProteaseTag® Active NE Immunoassay was provided gratis by ProAxsis Limited. This paper presents independent research funded by the National Institute for Health Research and the BRC. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.



Respiratory Research, 2019, 20:170

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/Organisation/COLLEGE OF LIFE SCIENCES/School of Medicine/Department of Infection, Immunity and Inflammation


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Abstract was presented by Samantha Thulborn at the BTS conference in 2016



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