Exhaled Nitric Oxide Fraction as an Add-On to ACQ-7 for Not Well Controlled Asthma Detection

Abstract

BackgroundThe measurement of fractional nitric oxide concentration in exhaled breath (FeNO), a noninvasive indicator of airway inflammation, remains controversial as a tool to assess asthma control. Guidelines currently limit asthma control assessment to symptom and spirometry based appraisals such as the Asthma Control Questionnaire-7 (ACQ-7). We aimed at determining whether adding FeNO to ACQ-7 improves current asthma clinical control assessment, through enhanced detection of not well controlled asthma.MethodsAsthmatic subjects, classified as not well controlled as per ACQ-7 on regular clinical practice, were included in a prospective, multicenter fashion, and had their maintenance treatment adjusted on visit 1. On follow-up (visit 2) four weeks later, the subjects were reevaluated as controlled or not well controlled using ACQ-7 versus a combination of FeNO and ACQ-7.ResultsOut of 381 subjects enrolled, 225 (59.1%) had not well controlled asthma on visit 2 as determined by ACQ-7, and 264 (69.3%) as per combined FeNO and ACQ-7. The combination of FeNO to ACQ-7 increased by 14.8% the detection of not well controlled asthma following maintenance therapy adjustment.ConclusionsThe addition of FeNO to ACQ-7 increased the detectability of not well controlled asthma upon adjustment of maintenance therapy. Adding a measure of airway inflammation to usual symptom and spirometry based scores increases the efficacy of current asthma clinical control assessment.

The Clinical Utility of Fractional Exhaled Nitric Oxide (FeNO) in Asthma Management

“…79 In a study with older population (ages>65 years), FeNO values were statistically significantly higher in those with uncontrolled asthma than those with controlled/partly controlled (regardless of whether asthma control was determined using GINA control criteria or using ACT with a cutoff of 19). 80 The association between asthma control and FeNO was weakened in patients on ICS as observed in four studies. 79,[81][82][83] In addition, pregnant women who had monthly FeNO measurements showed a weak correlation between FeNO and ACT and wide variation in FeNO values.…”

Sputum interleukin‐13 as a biomarker for the evaluation of asthma control

“…In a study by Volbeda et al it was shown that asthmatic subjects with well-controlled asthma had lower FeNO levels than the subjects with uncontrolled asthma [29]. In a study including 381 asthmatic subjects, the addition of FeNO to ACQ-7 increased by 14.8% the detectability of not well-controlled asthma upon adjustment of maintenance therapy [30]. In another study evaluating the longitudinal assessment of FeNO and sputum eosinophils, it was shown that both FeNO and sputum eosinophils are useful for titrating treatment in asthmatic patients to achieve better long-term control of the disease.…”

“…FeNO which has been primarily related to TH2 inflammation has also been prospectively used to guide asthma treatment, with conflicting results [5,28]. In a study including 381 asthmatic subjects, the addition of FeNO to ACQ-7 increased by 14.8% the detectability of not well-controlled asthma upon adjustment of maintenance therapy [30]. In a study including 381 asthmatic subjects, the addition of FeNO to ACQ-7 increased by 14.8% the detectability of not well-controlled asthma upon adjustment of maintenance therapy [30].…”

Combination of Fractional Exhaled Nitric Oxide (FeNO) Level and Asthma Control Test (ACT) in Detecting GINA-Defined Asthma Control in Treated Asthmatic Patients in Vietnam

“…Because of this reason, it is suggested to use a combination of FeNO level with other measurements such as spirometry or questionnaire for a complete assessment for the asthma control status in patients with asthma since asthma is a heterogeneous disease [18,19]. In the study of the combination of FeNO and questionnaire related to asthma control, Plaza et al found that the addition of FeNO to ACQ-7 (asthma control questionnaire) increased the detectability of not-well-controlled asthma (compare to using ACQ-7 alone) [20]. In this study, the authors found that the combination of FeNO to ACQ-7 increased the detection of uncontrolled asthma by 14.8% following the maintenance therapy adjustment.…”