Abstract
Introduction: Nitric oxide (NO) plays a role in immune responses to pathogens. Exhaled NO (eNO) is used as a noninvasive biomarker of airway inflammation in older children with asthma. However, the role for eNO in infancy has not been completely ascertained.
Aim: To investigate the association between eNO at 6 weeks of age and the incidence of bronchiolitis and respiratory symptoms in the first 12 months of life.
Methods: Infants at 6 weeks of age, born to mothers with asthma in pregnancy from the Breathing for Life Trial were assessed to measure eNO using a rapid-response chemiluminescence analyzer (CLD88;EcoMedics) interpolated to an expiratory flow of 50mL/s and normalized using square root (sq). We applied a standardised parent completed questionnaire at 12 months of age to investigate bronchiolitis and symptoms. Associations were investigated by multivariate linear and Poisson regression models.
Results: 184 babies had valid eNO measurements at 6 weeks of age, 125 (68%) had data at 12 months of age collected. Higher eNO was associated with less respiratory symptoms during the first weeks of life (n=155, ß-coefficient:–0.62, p=0.028). Babies without an episode of bronchiolitis in the first year of life had significantly higher eNO (3.60 ppb vs 3.11 ppb, p=0.009). Risk incidence of bronchiolitis, wheeze, cold or flu, short-acting beta-agonist use, and recurrent bronchiolitis significantly decreased by 18% to 24% for every increase in sq eNO ppb in multivariate models.
Conclusion: Infants with higher eNO levels at 6 weeks of age were significantly less likely to develop bronchiolitis and other respiratory symptoms at 12 months of age. In infancy, higher eNO levels may be a surrogate marker for more effective anti-viral immune responses.
Footnotes
Cite this article as: European Respiratory Journal 2021; 58: Suppl. 65, PA3069.
This abstract was presented at the 2021 ERS International Congress, in session “Prediction of exacerbations in patients with COPD”.
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 2021