G Roberts1, C Hurley, A Bush, G Lack. 1. Paediatric Allergy, Asthma and Immunology, Imperial College of St Mary's, London, UK.
Abstract
BACKGROUND: Exhaled nitric oxide (NO) has been proposed as a marker of airway eosinophilic inflammation in asthma. There is currently a paucity of longitudinal data relating it to allergen exposure and asthma symptoms. METHODS: Forty four children (6-16 years) with seasonal allergic asthma were sequentially followed before and during the grass pollen season. Asthma symptoms, lung function, NO levels, and pollen counts were recorded. The relationship between exhaled NO and both the pollen levels and asthma control were assessed longitudinally, comparing a subject's measurements with their previous ones. RESULTS: The median exhaled NO concentration was significantly increased during the pollen season (6.2 v 9.2 parts per billion (ppb), p<0.002; median change 2.9 ppb, 95% confidence interval 1.5 to 5.4). Exhaled NO was best associated with the mean pollen count in the week before measurement. It was also significantly associated with asthma control. CONCLUSIONS: The results suggest that, within a longitudinal model, the exhaled NO concentration is related to preceding allergen exposure and asthma control. It may be clinically more useful to compare exhaled NO values with a subject's previous values than to compare them with a population based normal range.
BACKGROUND: Exhaled nitric oxide (NO) has been proposed as a marker of airway eosinophilic inflammation in asthma. There is currently a paucity of longitudinal data relating it to allergen exposure and asthma symptoms. METHODS: Forty four children (6-16 years) with seasonal allergic asthma were sequentially followed before and during the grass pollen season. Asthma symptoms, lung function, NO levels, and pollen counts were recorded. The relationship between exhaled NO and both the pollen levels and asthma control were assessed longitudinally, comparing a subject's measurements with their previous ones. RESULTS: The median exhaled NO concentration was significantly increased during the pollen season (6.2 v 9.2 parts per billion (ppb), p<0.002; median change 2.9 ppb, 95% confidence interval 1.5 to 5.4). Exhaled NO was best associated with the mean pollen count in the week before measurement. It was also significantly associated with asthma control. CONCLUSIONS: The results suggest that, within a longitudinal model, the exhaled NO concentration is related to preceding allergen exposure and asthma control. It may be clinically more useful to compare exhaled NO values with a subject's previous values than to compare them with a population based normal range.
Authors: K Parameswaran; E Pizzichini; M M Pizzichini; P Hussack; A Efthimiadis; F E Hargreave Journal: Eur Respir J Date: 2000-03 Impact factor: 16.671
Authors: E Baraldi; S Carrá; C Dario; N Azzolin; R Ongaro; G Marcer; F Zacchello Journal: Am J Respir Crit Care Med Date: 1999-01 Impact factor: 21.405
Authors: Adam J Spanier; Robert S Kahn; Richard Hornung; Michelle Lierl; Bruce P Lanphear Journal: Pediatr Allergy Immunol Pulmonol Date: 2011-03 Impact factor: 1.349
Authors: Anne M Fitzpatrick; Benjamin M Gaston; Serpil C Erzurum; W Gerald Teague Journal: J Allergy Clin Immunol Date: 2006-10-10 Impact factor: 10.793
Authors: Adam J Spanier; Robert S Kahn; Richard W Hornung; Ning Wang; Guangyun Sun; Michelle B Lierl; Bruce P Lanphear Journal: Pediatr Pulmonol Date: 2009-08
Authors: Anna Selby; Bernie Clayton; Jane Grundy; Katy Pike; Kirsty Drew; Abid Raza; Ramesh Kurukulaaratchy; S Hasan Arshad; Graham Roberts Journal: Respir Res Date: 2010-04-23