- Conference Article
- 10.1183/13993003.congress-2025.pa2530
Home-based FeNO measurement in GINA 1-5 asthma: the FeNO@home study
- Sep 27, 2025
- Kai Michael Beeh + 5 more +5
<bold>RATIONALE:</bold> Daily FeNO may reflect airway T2 inflammation better than singular clinic data. <bold>Objectives:</bold> To compare longitudinal mean FeNO and variability (CV) in relation to asthma control; to compare sensitivity to detect T2<sub>FeNO</sub> inflammation at diagnostic (≥40 ppb in GINA 1) and on-treatment (≥25 ppb in GINA 2-5) cutoffs vs. single clinic values. <bold>Methods:</bold> Observational study with daily home-based FeNO (Vivatmo <italic>me</italic>) and symptom diary in asthmatics of different GINA steps over 3 months. Clinic FeNO, FEV<sub>1</sub>, and ACQ were also collected at 2 visits (enrollment/study end). <bold>Results:</bold> We enrolled n=85 patients (n=23 Step 1, n=37 Step 2-3, and n=25 Step 4-5). Mean daily FeNO over 3 months was highest in uncontrolled Step 4-5 (p=0.031), and FeNO variability in Step 2-3 (p=0.045). Overall, subjects with (+) sustained control (ACQ<0.75 both visits) had comparable mean FeNO values, but fewer proportion of patients with variability above the median CV vs. (-)sustained control patients (39.1 vs. 54.1%; p=0.03). Mean FeNO was elevated on symptomatic asthma days, particularly in Step 1 (p=0.001), with similar trends during loss of control phases. Home FeNO increased sensitivity to detect T2<sub>FeNO</sub> inflammation at diagnostic cutoff (Step 1) from 8.7% (clinic FeNO) to 47.8% of subjects. In GINA 2-3 and 4-5, sensitivity for on-treatment T2<sub>FeNO</sub> inflammation by home vs. clinic FeNO increased from 58.3% to 83.3%, and 64% to 96%, respectively. <bold>Conclusions:</bold> Daily FeNO provides important information about airway inflammation, complimentary to symptom control. Further, detection of T2 inflammation in asthmatics is improved at all GINA steps at both diagnostic and predictive/prognostic cutoffs, with important implications for management and diagnosis.
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