RT Journal Article SR Electronic T1 Activation of epithelial and inflammatory pathways in adolescent elite athletes exposed to intense exercise and air pollution JF Thorax JO Thorax FD BMJ Publishing Group Ltd and British Thoracic Society SP thorax-2022-219651 DO 10.1136/thorax-2022-219651 A1 Janne Goossens A1 Anne-Charlotte Jonckheere A1 Sven F Seys A1 Ellen Dilissen A1 Tatjana Decaesteker A1 Camille Goossens A1 Koen Peers A1 Vincent Vanbelle A1 Jeroen Stappers A1 Sven Aertgeerts A1 Barbara De Wilde A1 Jasmine Leus A1 Sophie Verelst A1 Marc Raes A1 Lieven Dupont A1 Dominique M Bullens YR 2023 UL http://thorax.bmj.com/content/early/2023/03/16/thorax-2022-219651.abstract AB Rationale Participation in high-intensity exercise in early life might act as stressor to the airway barrier.Objectives To investigate the effect of intense exercise and associated exposure to air pollution on the airway barrier in adolescent elite athletes compared with healthy controls and to study exercise-induced bronchoconstriction (EIB) in this population.Methods Early-career elite athletes attending ‘Flemish-Elite-Sports-Schools’ (12–18 years) of 4 different sport disciplines (n=90) and control subjects (n=25) were recruited. Presence of EIB was tested by the eucapnic voluntary hyperventilation (EVH) test. Markers at mRNA and protein level; RNA-sequencing; carbon load in airway macrophages were studied on induced sputum samples.Results 444 genes were differentially expressed in sputum from athletes compared with controls, which were related to inflammation and epithelial cell damage and sputum samples of athletes contained significantly more carbon loaded airway macrophages compared with controls (24%, 95% CI 20% to 36%, p<0.0004). Athletes had significantly higher substance P (13.3 pg/mL, 95% CI 2.0 to 19.2) and calprotectin (1237 ng/mL, 95% CI 531 to 2490) levels as well as IL-6, IL-8 and TNF-α mRNA levels compared with controls (p<0.05). The incidence of EIB in athletes was 9%. The maximal fall in forced expiratory volume in 1 s (%) after EVH test in athletes was significantly associated with prior PM10 and PM2.5 exposure.Conclusion Early-career elite athletes showed increased markers of air pollution exposure, epithelial damage and airway inflammation compared with controls. Acute exposure to increased air pollution PM10 levels was linked to increased airway hyper-reactivity.Trial registration number NCT03587675.Data are available in a public, open access repository. We will provide the data in open access to allow analysis over different study cohorts in for example a systematic review.