FeNO as a Marker of Airways Inflammation: The Possible Implications in Childhood Asthma Management

Abstract

The aim of this study was to verify FeNO usefulness, as a marker of bronchial inflammation, in the assessment of therapeutic management of childhood asthma. We performed a prospective 1-year randomized clinical trial evaluating two groups of 32 children with allergic asthma: “GINA group”, in which therapy was assessed only by GINA guidelines and “FeNO group”, who followed a therapeutic program assessed also on FeNO measurements. Asthma Severity score (ASs), Asthma Exacerbation Frequency (AEf), and Asthma Therapy score (ATs) were evaluated at the start of the study (T1), 6 months (T2), and 1 year after (T3). ASs and AEf significantly decreased only in the FeNO group at times T2 and T3 (p[T1-T2] = 0.0001, and p[T1-T3] = 0.01; p[T1-T2] = 0.0001; and p[T1-T3] < 0.0001, resp.). After six months of follow-up, we found a significant increase of patients under inhaled corticosteroid and/or antileukotrienes in the GINA group compared to the FeNO group (P = .02). Our data show that FeNO measurements, might be a very useful additional parameter for management of asthma, which is able to avoid unnecessary inhaled corticosteroid and antileukotrienes therapies, however, mantaining a treatment sufficient to obtain a meaningful improvement of asthma.

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

“…In one RCT, FeNO concentrations in adolescents with adherence of more than 50 percent of assigned doses of mostly ICS (measured using a built-in dose counter and a structured questionnaire) was 24 ppb compared to 31ppb in those with <50 percent adherence. 114 A second study in children demonstrated that FeNO values were associated with adherence to inhaled budesonide (r 2 =0.59) as assessed using dose counters 115 . A third study also in children showed that high FeNO level (>25 ppb) was associated with lower adherence rates to any asthma medication using the parental reported Medication Adherence Report Scale (OR: 0.4; 95% CI: 0.3-0.6).…”

Measurement of exhaled nitric oxide concentration in asthma: a systematic review and economic evaluation of NIOX MINO, NIOX VERO and NObreath

“…Fritsch et al 103 did not report the reasons for participant withdrawal or correction for missing FeNO values and there may have been missing outcome data in the study by Petsky et al, 107 but this is unknown as only a conference abstract of this study was identified. In the study by Verini et al 105 it was reported that 64 patients were recruited; however, it was unclear whether this was the total number after dropout or whether no participants dropped out. Consequently, the study was rated as 'unclear' on outcome data completeness.…”

“…In the study by Fritsch et al, 103 medication usage was reported as median (IQR) values rather than mean values and so these values could not be used in the planned meta-analysis; however, although planned, a meta-analysis was not possible because of study heterogeneity and so this bias did not affect the synthesis of data. The study by Verini et al 105 was rated as having a low risk of bias for selective reporting; respiratory function and immunoallergological parameters were inadequately reported (i.e. no numerical data were provided; it was stated only that there were no significant between-group differences on these outcomes), but these outcomes were not of relevance to this review.…”

“…Peirsman et al 109 blinded participants but not personnel. Neither Petsky et al 107 nor Verini et al 105 provided sufficient information to make a judgement on participant and personnel blinding and so these studies were rated as 'unclear'. As many of the step-up/step-down protocols and criteria for exacerbations were based on participant symptom reporting and physician judgement, any potential lack of blinding in the studies could significantly affect the direction and size of the outcomes.…”

Exhaled NO: Determinants and Clinical Application in Children With Allergic Airway Disease

“…2 Accordingly, FeNO has gained substantial clinical and scientific interest since it is seen as a safer and less invasive alternative tool to bronchoscopy or induced sputum for diagnosis, monitoring, or predicting the response to the treatment of airway inflammation, especially in children. 3 Therefore, this review focuses on the clinical application of FeNO in children with allergic airway disease and the environmental and other factors that need to be considered when interpreting the results from FeNO measurements. and activity of the enzymes responsible for producing NO, the concentration of substrates, the level of oxidative stress and its rate of uptake by antioxidant molecules (Fig.…”