Longitudinal changes in sputum and blood inflammatory mediators during FeNO suppression testing. Issue 9 (8th July 2022)

• Record Type: Journal Article
• Authors: Couillard, Simon; Shrimanker, Rahul; Lemaire-Paquette, Samuel; Hynes, Gareth M; Borg, Catherine; Connolly, Clare; Thulborn, Samantha Jane; Moran, Angela; Poole, Sarah; Morgan, Sophie; Powell, Timothy; Pavord, Ian; Hinks, Timothy
• Is Part Of: Thorax. Volume 77:Issue 9(2022)
• Page Start: 933
• Page End: 938
• Publication Date: 2022-07-08
• Subjects: Asthma -- Pulmonary eosinophilia -- Exhaled Airway Markers -- Airway Epithelium -- Asthma Mechanisms; Chest -- Diseases -- Periodicals; Thorax; Chest -- Diseases; Periodicals; Periodicals; 617.54
• DOI: 10.1136/thoraxjnl-2021-217994
• Languages: English
• ISSNs: 0040-6376

Abstract

Abstract : To explore whether fractional exhaled nitric oxide (FeNO) non-suppression identifies corticosteroid resistance, we analysed inflammatory mediator changes during a FeNO suppression test with monitored high-intensity corticosteroid therapy. In linear mixed-effects models analysed over time, the 15 clinically distinct 'suppressors' (ie, ≥ 42% FeNO suppression) normalised Asthma Control Questionnaire scores (mean±SD, start to end of test: 2.8±1.4 to 1.4±0.9, p<0.0001) and sputum eosinophil counts (median (IQR), start to end of test: 29% (6%–41%) to 1% (1%–5%), p=0.0003) while significantly decreasing sputum prostaglandin D2 (254 (89–894) to 93 (49–209) pg/mL, p=0.004) and numerically decreasing other type-2 cytokine, chemokine and alarmin levels. In comparison, the 19 non-suppressors had persistent sputum eosinophilia (10% (1%–67%) despite high-intensity therapy) with raised end-test inflammatory mediator levels (1.9 (0.9–2.8)-fold greater than suppressors). FeNO non-suppression during monitored treatment implies biological corticosteroid resistance.