Change in FEV1 and Feno Measurements as Predictors of Future Asthma Outcomes in Children

Abstract

BACKGROUND: Repeated measurements of spirometry and fractional exhaled nitric oxide (FENO) are recommended as part of the management of childhood asthma, but the evidence base for such recommendations is small. We tested the hypothesis that reducing spirometric indices or increasing FENO will predict poor future asthma outcomes.METHODS: A one-stage individual patient data meta-analysis used data from seven randomized controlled trials in which FENO was used to guide asthma treatment; spirometric indices were also measured. Change in %FEV 1 and % change in FENO between baseline and 3 months were related to having poor asthma control and to having an asthma exacerbation between 3 and 6 months after baseline.RESULTS: Data were available from 1,112 children (mean age, 12.6 years; mean %FEV 1 , 94%). A 10% reduction in %FEV 1 between baseline and 3 months was associated with 28% increased odds for asthma exacerbation (95% CI, 3-58) and with 21% increased odds for having poor asthma control (95% CI, 0-45) 6 months after baseline. A 50% increase in FENO between baseline and 3 months was associated with 11% increase in odds for poor asthma control 6 months after baseline (95% CI, 0-16). Baseline FENO and %FEV 1 were not related to asthma outcomes at 3 months.CONCLUSIONS: Repeated measurements of %FEV 1 that are typically within the "normal" range add to clinical risk assessment of future asthma outcomes in children. The role of repeated FENO measurements is less certain because large changes were associated with small changes in outcome risk.

Associations of Th2, Th17, Treg cells, and IgA+ memory B cells with atopic disease in children: The Generation R Study

“…As higher memory Treg cells represent chronic inflammation, naive cells have no memory of sensitization to specific antigens. 33,48,49 Children with better lung functions are less likely to have asthma, 50,51 and indeed, high naive Tregs suggest that these children had no chronic immune activation compared to children with allergic sensitization and atopic dermatitis. 33 However, we did not observe lower Treg-memory cells in children with better lung function.…”

Relationship between immune parameters during a severe exacerbation in allergic asthmatic children and asthma outcomes in the following year

“…Poor control and history of exacerbation are known risk factors of future exacerbation . Fielding et al have recently confirmed the link between altered lung function and poor asthma control and risk of exacerbation . Thus, improving the identification of patients at risk of exacerbations remains an urgent unmet need in childhood asthma …”

What is a clinically meaningful change in exhaled nitric oxide for children with asthma?

“…[21][22][23][24][25][26][27] Participant details at baseline are presented in Table 1 and have also been described elsewhere. 18 The mean (SD) participant age was 12.6 (3.1) years and 58% of participants were male.…”

“…Our group has pooled the data collected in more than 1000 participants in seven randomized controlled trials (RCTs) where F E NO was used to guide asthma treatment . This analysis found that a 50% increase in FeNO between baseline and 3 months was associated with 11% increase in odds for poor asthma control 6 months after baseline . We used individual patient data from the same database of seven RCTs to address the question “What is the variability in F E NO over 3 months among children with stable asthma?”.…”