Extended nitric oxide analysis may improve personalized anti-inflammatory treatment in asthmatic children with intermediate FENO50
2015 (English)In: Journal of Breath Research, ISSN 1752-7155, E-ISSN 1752-7163, Vol. 9, no 4, 047114Article in journal (Refereed) Published
Exhaled nitric oxide (FENO) is elevated in asthma, and a clinical practice guideline has been published with recommendations for anti-inflammatory treatment. It summarizes that a FENO at an expiratory flow rate of 50 ml s−1 (FENO50) above 35 ppb in children indicates eosinophilic inflammation, and the most likely response is to use inhaled corticosteroids. Intermediate FENO50 between 20–35 ppb should be interpreted cautiously. The aim of the study was to investigate this guideline in a small group of asthmatic children.
Thirty-seven asthmatic children; 23 boys and 14 girls, visited the outpatient clinic, and provided exhaled breath samples for offline NO measurement. These samples were analysed with chemiluminescence techniques. Three flow rates, namely 16, 90 and 230 ml s−1 were used for the extended NO analysis (Högman–Meriläinen algorithm, HMA) to estimate the alveolar concentration (CANO), diffusion rate of the airway wall (DawNO) and airway wall content (CawNO).
For accuracy of the HMA, the estimated value of FENO at 50 ml s−1 (FENO50) was compared with measured FENO50. In nine children the difference was more than 5 ppb and the data were therefore excluded. Five children with FENO50 <20 ppb had no known allergy and their FENO50 geometrical mean (25th; 75th percentile) was 11 (10;14) and CawNO was 32 (20;43) ppb. Ten children with FENO50 > 35 ppb had an allergy and had FENO50 of 56 (47;60) ppb and CawNO of 140 (121;172) ppb. Thirteen children with allergies, with intermediate FENO50, had FENO50 of 27 (25;30) ppb with a wide range of CawNO. In five of these children, values were comparable to healthy children, 44 (43;50) ppb while eight children had elevated CawNO values of 108 (95;129) ppb.
Our data indicate the clinical potential use of extended NO analysis to determine the personal target value of FENO50 for monitoring the treatment outcome. Furthermore, for children with intermediate FENO50 more than half of them could possibly benefit from an adjustment of inhaled corticosteroids if the CawNO value was considered.
Place, publisher, year, edition, pages
2015. Vol. 9, no 4, 047114
nitric oxide, asthma, children, mathematical model
Respiratory Medicine and Allergy
Research subject Medical Science
IdentifiersURN: urn:nbn:se:uu:diva-275029DOI: 10.1088/1752-7155/9/4/047114ISI: 000367936100017PubMedID: 26670199OAI: oai:DiVA.org:uu-275029DiVA: diva2:898488
FunderEU, European Research Council