Abstract
Introduction: Neutrophil elastase (NE) activity in sputum can identify patients at high risk of airway infection and exacerbations in bronchiectasis. Application of this biomarker in clinical practice is limited because no point of care test is available. We tested whether a novel semi-quantitative lateral flow device (Neutrophil elastase airway test stik–NEATstik®) can stratify bronchiectasis patients according to severity, airway infection and exacerbation risk.
Methods: Sputum samples from 124 patients with stable bronchiectasis enrolled in the UK and Spain were tested using the NEATstik®, which scores NE concentration from 0 (<8µg/ml elastase activity) to 10 (maximum detectable NE activity). High NE activity was regarded as a European Respiratory Journal NEATstik® grade>6. Severity of disease, airway infection from sputum culture and exacerbations over the 12-months were recorded. An independent validation was conducted in 50 patients from Milan, Italy.
Results: Patients had a median age of 69 years and FEV1 69%. High NE activity was associated with worse bronchiectasis severity using the bronchiectasis severity index (p=0.0007) and FEV1 (p=0.02). A high NEATstik® grade was associated with a significant increase in exacerbation frequency, incident rate ratio 2.75 95%CI 1.63-4.64, p6 was 113 days compared to 278 days. The hazard ratio was 2.40 95% CI 1.54-3.76,p=0.0001. Results were confirmed in the independent validation cohort.
Conclusions: A novel lateral flow device provides assessment of NE activity from sputum in minutes and identifies patients at increasing risk of airway infection and future exacerbations.
Footnotes
Cite this article as: European Respiratory Journal 2019; 54: Suppl. 63, OA4947.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2019