Scottish Centre for Respiratory Research, University of Dundee, Ninewells Hospital and Medical School, Dundee, UK.
Hospital Professor Fernando Fonseca (HFF), Lisbon, Portugal.
Eur Respir J. 2019 Jun 13;53(6). doi: 10.1183/13993003.00303-2019. Print 2019 Jun.
Neutrophil elastase 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 stick - NEATstik®) can stratify bronchiectasis patients according to severity, airway infection and exacerbation risk.
Sputum samples from 124 patients with stable bronchiectasis enrolled in the UK and Spain were tested using the NEATstik®, which scores neutrophil elastase concentration from 0 (<8 µg·mL elastase activity) to 10 (maximum detectable neutrophil elastase activity). High neutrophil elastase activity was regarded as a 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.
Patients had a median age of 69 years and forced expiratory volume in 1 s (FEV) 69%. High neutrophil elastase activity was associated with worse bronchiectasis severity using the bronchiectasis severity index (p=0.0007) and FEV (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, p<0.001). The median time to next exacerbation for patients with a NEATstik® grade >6 was 103 days compared to 278 days. The hazard ratio was 2.59 (95% CI 1.71-3.94, p<0.001). Results were confirmed in the independent validation cohort.
A novel lateral flow device provides assessment of neutrophil elastase activity from sputum in minutes and identifies patients at increasing risk of airway infection and future exacerbations.
痰中的中性粒细胞弹性蛋白酶活性可识别支气管扩张症患者中气道感染和恶化的高危人群。由于没有即时检测（point-of-care test），该生物标志物在临床实践中的应用受到限制。我们测试了一种新型半定量横向流动设备（中性粒细胞弹性蛋白酶气道检测棒 - NEATstik®）是否可以根据严重程度、气道感染和恶化风险对支气管扩张症患者进行分层。
来自英国和西班牙的 124 名稳定期支气管扩张症患者的痰液样本使用 NEATstik®进行检测，该检测对中性粒细胞弹性蛋白酶浓度进行评分，范围从 0（<8 µg·mL 弹性蛋白酶活性）到 10（可检测到的最大中性粒细胞弹性蛋白酶活性）。高中性粒细胞弹性蛋白酶活性被视为 NEATstik®等级>6。记录 12 个月内的疾病严重程度、痰培养的气道感染和恶化情况。在意大利米兰的 50 名患者中进行了独立验证。
患者的中位年龄为 69 岁，用力呼气量（FEV）为 69%。高中性粒细胞弹性蛋白酶活性与支气管扩张症严重程度指数（p=0.0007）和 FEV（p=0.02）相关。高 NEATstik®等级与恶化频率显著增加相关，发生率比为 2.75（95%CI 1.63-4.64，p<0.001）。NEATstik®等级>6 的患者下一次恶化的中位时间为 103 天，而 278 天。风险比为 2.59（95%CI 1.71-3.94，p<0.001）。结果在独立验证队列中得到证实。
新型横向流动设备可在数分钟内评估痰液中的中性粒细胞弹性蛋白酶活性，并识别气道感染和未来恶化风险增加的患者。
