Airway sensory nerve sensitivity in adolescents with eosinophilic and non-eosinophilic asthma

Background: Neural pathways may play a role in non-eosinophilic asthma, but this has rarely been studied. Aims: To assess whether non-eosinophilic asthma is characterised by increased sensory nerve sensitivity compared to eosinophilic asthmatics and controls. Methods: We recruited 38 asthmatics (18 eosinophilic and 20 non-eosinophilic) and 19 non-asthmatics (14-21 years) who underwent a capsaicin challenge, combined sputum induction and airway hyperreactivity (AHR), exhaled nitric oxide (FENO), atopy and spirometry tests. Sensory nerve sensitivity was defined as the lowest capsaicin concentration that evoked 2 (C2) or 5 (C5) coughs. Results: Non-eosinophilic asthmatics (NEA; eosinophil cut-point Conclusion: Heightened airway sensory sensitivity may play a role in non-eosinophilic asthma.