Association of longitudinal fractional exhaled nitric oxide measurements with asthma control in atopic children

Domiciliary monitoring of exhaled nitric oxide in the management of asthma: a pilot study

BACKGROUND

Whether asthma patients could benefit from home monitoring for fractional exhaled nitric oxide (flow of 50 mL/s, FeNO50) is unknown. We explore the application value of home monitoring FeNO50 in daily asthma management.

METHODS

Twenty-two untreated, uncontrolled asthma patients were selected. Medical history, blood and sputum samples, pulmonary function, Asthma Control Test (ACT), and other clinical data of the subjects were collected. All subjects underwent daily monitoring for four weeks using a FeNO50 monitor and mobile spirometry (mSpirometry). The diurnal differences and dynamic changes were described. Compare the effect-acting time and the relative plateau of treatment between FeNO50 and mSpirometry monitoring.

RESULTS

In the first two weeks, the morning median (IQR) level of FeNO50 was 44 (35, 56) ppb, which was significantly higher than the evening median level [41 (32, 53) ppb, P = 0.028]. The median (IQR) effect-acting time assessed by FeNO50 was 4 (3, 5) days, which was significantly earlier than each measure of mSpirometry (P < 0.05). FeNO50 reached the relative plateau significantly earlier than FEV1 (15 ± 2 days vs. 21 ± 3 days, P < 0.001). After treatment, the daily and weekly variation rates of FeNO50 showed a gradually decreasing trend (P < 0.05). The ACT score, sputum eosinophils, and blood eosinophils also significantly improved (P ≤ 0.01).

CONCLUSIONS

The daily home monitoring of FeNO50 in asthmatic patients showed significant circadian rhythm, and the sensitivity of FeNO50 in evaluating the response to treatment was higher than mSpirometry. The daily and weekly variation rates of FeNO50 change dynamically with time, which may be used to assess the condition of asthma.

Asthma medication adherence and exacerbations and lung function in children managed in Leicester primary care

Poor adherence to asthma preventer medication is associated with life-threatening asthma attacks. The quality and outcomes framework mandated primary care annual asthma review does not include adherence monitoring and the effect of poor adherence on lung function in paediatric primary care patients is unknown. The aim was to investigate the link between inhaled corticosteroid (ICS) adherence and spirometry, fraction of exhaled nitric oxide (FeNO) and asthma control in asthmatic school-age children in this cross-sectional observational study involving three Leicestershire general practices. Children 5-16 years on the practice's asthma registers, were invited for a routine annual asthma review between August 2018 and August 2019. Prescription and clinical data were extracted from practice databases. Spirometry, bronchodilator reversibility (BDR) and FeNO testing were performed as part of the review. 130 of 205 eligible children (63.4%) attended their review. Mean adherence to ICS was 36.2% (SEM 2.1%) and only 14.6% of children had good adherence (≥75% prescriptions issued). We found no differences in asthma exacerbations in the preceding 12 months between the adherence quartiles. 28.6% of children in the lowest and 5.6% in the highest adherence quartile had BDR ≥ 12% but this was not statistically significant (p = 0.55). A single high FeNO value did not predict adherence to ICS. Adherence to ICS in children with asthma in primary care is poor. The link between adherence to ICS and asthma exacerbations, spirometry and FeNO is complex but knowledge of adherence to ICS is critical in the management of children with asthma.

Fractional exhaled nitric oxide as a determinant for the clinical course of asthma: a systematic review

Background: Precision medicine means linking the right patient to the right management strategy including best possible pharmacological therapy, considering the individual variability of the disease characteristics, type of inflammation, genes, environment, and lifestyle. For heterogenous diseases such as asthma, reliable biomarkers are needed to facilitate the best possible disease control and reduce the risk of side effects. The present review examines fractional exhaled nitric oxide (FeNO) as a guide for the management strategy of asthma and predictor of its clinical course.

Method: The literature included was identified by searching the PubMed database using specific key words and MeSH terms. Studies were not excluded based on their design alone. The search resulted in 212 hits, of which 35 articles were included in this review.

Results: Several studies support a potential role for high FeNO levels as a prognostic biomarker for accelerated lung function decline in adults with newly diagnosed asthma. Furthermore, studies report an association between high FeNO levels and excess decline in FEV₁ in adults with long-standing moderate to severe asthma despite optimised therapy, whereas the findings for patients with less severe disease are conflicting. Applying a FeNO-based management algorithm reduces the exacerbation rate in adults with asthma. Similar observations are seen in children, though based on fewer studies. The available studies provide evidence that the level of FeNO may be useful as a predictor of subsequent loss of asthma control in adults, though the evidence is somewhat conflicting in children and young adults.

Conclusion: The present review provides evidence of the prognostic value of FeNO as a surrogate biomarker for type 2 inflammation in the airways. FeNO is likely to emerge as an important biomarker in monitoring and tailoring modern asthma treatment, either alone or in combination with other biomarkers.

Fractional Exhaled Nitric Oxide (FENO) in the management of asthma: a position paper of the Italian Respiratory Society (SIP/IRS) and Italian Society of Allergy, Asthma and Clinical Immunology (SIAAIC)

Asthma prevalence in Italy is on the rise and is estimated to be over 6% of the general population. The diagnosis of asthma can be challenging and elusive, especially in children and the last two decades has brought evidences that asthma is not a single disease but consists of various phenotypes. Symptoms can be underestimated by the patient or underreported to the clinician and physical signs can be scanty. Usual objective measures, like spirometry, are necessary but sometimes not significant. Despite proper treatment, asthma can be a very severe condition (even leading to death), however new drugs have recently become available which can be very effective in its control. Since asthma is currently thought to be caused by inflammation, a direct measure of the latter can be of paramount importance. For this purpose, the measurement of Fractional Exhaled Nitric Oxide (FE_NO) has been used since the early years of the current century as a non-invasive, easy-to-assess tool useful for diagnosing and managing asthma. This SIP-IRS/SIAAIC Position Paper is a narrative review which summarizes the evidence behind the usefulness of FE_NO in the diagnosis, management and phenotypization of asthma.

Fractional exhaled nitric oxide and forced expiratory volume in 1 second/forced vital capacity have predictive value of asthma exacerbation in Korean school children

Background

The incidence of asthma exacerbation (AE) and the predictive value of spirometry and fractional exhaled nitric oxide (FeNO) in school children have not been evaluated.

Objective

We sought to evaluate the efficacy of spirometry measurement and FeNO monitoring for predicting AE in school children in the Cheongju area in Korea.

Methods

With parental agreement, we studied 170 students aged 7–12 years. Children were evaluated by an asthma specialist using baseline spirometry, skin prick test, seasonal FeNO measurement, and asthma control test. The study participants underwent a physical examination and their medical history was also evaluated by the specialist. They were assessed for asthma control status during regular doctor visits for 1 year.

Results

In total, 160 children (94.1%) completed follow-up and FeNO monitoring. Of which, 26 children (16.3%) had AE. AE was associated with male children and children with allergic rhinitis (p < 0.05). While, children with AE tended to have higher FeNO than those without AE, no significant difference was found. The maximum value of FeNO ≥35 ppb was associated with AE (p < 0.05). Children with AE had a significantly decreased baseline forced expiratory volume in 1 second/forced vital capacity (FEV₁/FVC), %predicted, forced expiratory flow at 25%–75% of FVC (FEF_25%–75%). FEV₁/FVC < 80% was associated with AE in children regardless of inhalant allergen sensitization (all p < 0.05).

Conclusion

Baseline spirometry had a predictive value of AE in school children. Sensitive spirometric parameters such as FEV₁/FVC and FEF_25%–75% can be used as prognostic factors to predict future childhood AE. FeNO value ≥ 35 ppb during monitoring was associated with AE in school children.

Lung function and asthma control in school-age children managed in UK primary care: a cohort study

BACKGROUND

Spirometry and fraction of exhaled nitric oxide (FeNO) are commonly used in specialist centres to monitor children with asthma. The National Institute for Health and Care Excellence recommends spirometry for asthma monitoring from 5 years in all healthcare settings. There is little spirometry and FeNO data in children managed for asthma in UK primary care to support their use.

OBJECTIVES

To study the prevalence of abnormal spirometry and FeNO in children with asthma managed in primary care and to explore their relationship with asthma control and unplanned healthcare attendances (UHA).

METHODS

Prospective observational cohort study in children aged 5-16 years with suspected or doctor-diagnosed asthma attending an asthma review in UK general practice. Spirometry, FeNO, asthma control test (ACT) scores and number of UHAs were studied.

RESULTS

Of 612 children from 10 general practices, 23.5% had abnormal spirometry, 36.0% had raised FeNO ≥35 parts per billion and 41.8% reported poor control. Fifty-four per cent of children reporting good asthma control had abnormal spirometry and/or raised FeNO. At follow-up, the mean number of UHAs fell from 0.31/child in the 6 months preceding review to 0.20/child over the 6 months following review (p=0.0004). Median ACT scores improved from 20 to 22 (p=0.032), and children's ACT from 21 to 23 (p<0.0001).

CONCLUSIONS

Abnormal lung function and FeNO are common in children attending for asthma review in primary care and relate poorly to symptom scores. A symptoms-based approach to asthma monitoring without objective testing is likely to miss children at high risk of future severe asthma attacks.

Do clinical investigations predict long-term wheeze? A follow-up of pediatric respiratory outpatients

INTRODUCTION

The contribution of clinical investigations to prediction of long-term outcomes of children investigated for asthma is unclear.

AIM

We performed a broad range of clinical tests and investigated whether they helped to predict long-term wheeze among children referred for evaluation of possible asthma.

METHODS

We studied children aged 6 to 16 years referred to two Swiss pulmonary outpatient clinics with a history of wheeze, dyspnea, or cough in 2007. The initial assessment included spirometry, fractional exhaled nitric oxide, skin prick tests, and bronchial provocation tests by exercise, methacholine, and mannitol. Respiratory symptoms were assessed with questionnaires at baseline and at follow-up 7 years later. Associations between baseline factors and wheeze at follow-up were investigated by logistic regression.

RESULTS

At baseline, 111 children were examined in 2007. After 7 years, 85 (77%) completed the follow-up questionnaire, among whom 61 (72%) had wheeze at baseline, while at follow-up 39 (46%) reported wheeze. Adjusting for age and sex, the following characteristics predicted wheeze at adolescence: wheeze triggered by pets (odds ratio, 4.2; 95% CI, 1.2-14.8), pollen (2.8, 1.1-7.0), and exercise (3.1, 1.2-8.0). Of the clinical tests, only a positive exercise test (3.2, 1.1-9.7) predicted wheeze at adolescence.

CONCLUSION

Reported exercise-induced wheeze and wheeze triggered by pets or pollen were important predictors of wheeze persistence into adolescence. None of the clinical tests predicted wheeze more strongly than reported symptoms. Clinical tests might be important for asthma diagnosis but medical history is more helpful in predicting prognosis in children referred for asthma.

Moving toward consensus on diagnosis and management of severe asthma in children

Children with severe asthma continue to experience symptoms despite long-term treatment with high doses of corticosteroids. Moreover, the heterogeneous nature of asthma and the presence of several phenotypes have limited our ability to develop an optimized management strategy for these patients. Adequate management of severe asthma in children necessitates a detailed understanding of what makes asthma difficult to control, knowledge of the causal factors, review of diagnosis for accurate identification of pediatric patients with severe asthma and a precise definition of the phenotypes to be able to better target the therapy. Advancement in all these aspects is likely to improve childhood asthma treatment in the future. Although our understanding of severe pediatric asthma has grown in recent years, there remains a lack of consensus and clarity around critical aspects of this condition. This review attempts to present a harmonized view on the definition of severe asthma in the pediatric age group, identification of phenotypes and diagnosis, the inflammatory cascade, pharmacological and non-pharmacological treatment strategies, considerations for follow-up and referral to specialists, and disease prevention strategies.

Severe bronchial asthma in children: a review of novel biomarkers used as predictors of the disease

Severe asthma or therapy-resistant asthma in children is a heterogeneous disease that affects all age-groups. Given its heterogeneity, precision in diagnosis and treatment has become imperative, in order to achieve better outcomes. If one is thus able to identify specific patient phenotypes and endotypes using the appropriate biomarkers, it will assist in providing the patient with more personalized and appropriate treatment. However, there appears to be a huge diagnostic gap in severe asthma, as there is no single test yet that accurately determines disease phenotype. In this paper, we review the published literature on some of these biomarkers and their possible role in bridging this diagnostic gap. We also highlight the cellular and molecular mechanisms involved in severe asthma, in order to show the basis for the novel biomarkers. Some markers useful for monitoring therapy and assessing airway remodeling in the disease are also discussed. A review of the literature was conducted with PubMed to gather baseline data on the subject. The literature search extended to articles published within the last 40 years. Although biomarkers specific to different severe asthma phenotypes have been identified, progress in their utility remains slow, because of several disease mechanisms, the variation of biomarkers at different levels of inflammation, changes in relying on one test over time (eg, from sputum eosinophilia to blood eosinophilia), and the degree of invasive tests required to collect biomarkers, which limits their applicability in clinical settings. In conclusion, several biomarkers remain useful in recognizing various asthma phenotypes. However, due to disease heterogeneity, identification and utilization of ideal and defined biomarkers in severe asthma are still inconclusive. The development of novel serum/sputum-based biomarker panels with enhanced sensitivity and specificity may lead to prompt diagnosis of the disease in the future.

Combined use of fractional exhaled nitric oxide and bronchodilator response in predicting future loss of asthma control among children with atopic asthma

BACKGROUND AND OBJECTIVE

Recognition of patients at risk of asthma exacerbation is important for future asthma care and improved outcome. The aim of the present study was to see whether measurements of bronchodilator response (BDR) and fractional exhaled nitric oxide (FeNO) in combination provide prognostic information superior to either measurement alone in children with atopic asthma.

METHODS

A total of 201 atopic children aged 8-16 years with intermittent or mild persistent asthma were included. Pulmonary function tests including BDR and FeNO were serially monitored 10 times or more over 2 years when subjects were not receiving controller medications. After completion of monitoring, 1-year observation for a loss of asthma control was performed.

RESULTS

During the monitoring period, positive BDRs (≥12% in forced expiratory volume in 1 s (FEV₁ ) from pre-bronchodilator value) and FeNO higher than 35 parts per billion (ppb) were observed at least once in 59% and 77% of participants. When analysed as continuous variables, both BDR (hazard ratio (HR): 1.21; 95% CI: 1.04-1.41; P = 0.014) and FeNO (HR: 1.27; 95% CI: 1.09-1.49; P = 0.003) were associated with increased risks for a control loss. Compared with patients showing either positive BDRs (HR: 3.19; 95% CI: 1.05-9.64) or FeNO higher than 35 ppb (HR: 4.70; 95% CI: 1.68-13.11), patients with both findings (HR: 7.08; 95% CI: 2.57-19.49) had greater risks for a control loss.

CONCLUSION

These data support that combined use of BDR and FeNO measurements can modify predictive risk obtained from either measurement alone.

Progress in pediatrics in 2015: choices in allergy, endocrinology, gastroenterology, genetics, haematology, infectious diseases, neonatology, nephrology, neurology, nutrition, oncology and pulmonology

This review focuses key advances in different pediatric fields that were published in Italian Journal of Pediatrics and in international journals in 2015. Weaning studies continue to show promise for preventing food allergy. New diagnostic tools are available for identifying the allergic origin of allergic-like symptoms. Advances have been reported in obesity, short stature and autoimmune endocrine disorders. New molecules are offered to reduce weight gain and insulin-resistance in obese children. Regional investigations may provide suggestions for preventing short stature. Epidemiological studies have evidenced the high incidence of Graves' disease and Hashimoto's thyroiditis in patients with Down syndrome. Documentation of novel risk factors for celiac disease are of use to develop strategies for prevention in the population at-risk. Diagnostic criteria for non-celiac gluten sensitivity have been reported. Negative effect on nervous system development of the supernumerary X chromosome in Klinefelter syndrome has emerged. Improvements have been made in understanding rare diseases such as Rubinstein-Taybi syndrome. Eltrombopag is an effective therapy for immune trombocytopenia. Children with sickle-cell anemia are at risk for nocturnal enuresis. Invasive diseases caused by Streptococcus pyogenes are still common despite of vaccination. No difference in frequency of antibiotic prescriptions for acute otitis media between before the publication of the national guideline and after has been found. The importance of timing of iron administration in low birth weight infants, the effect of probiotics for preventing necrotising enterocolitis and perspectives for managing jaundice and cholestasis in neonates have been highlighted. New strategies have been developed to reduce the risk for relapse in nephrotic syndrome including prednisolone during upper respiratory infection. Insights into the pathophysiology of cerebral palsy, arterial ischemic stroke and acute encephalitis may drive advances in treatment. Recommendations on breastfeeding and complementary feeding have been updated. Novel treatments for rhabdomyosarcoma should be considered for paediatric patients. Control of risk factors for bronchiolitis and administration of pavilizumab for preventing respiratory syncytial virus infection may reduce hospitalization. Identification of risk factors for hospitalization in children with wheezing can improve the management of this disease. Deletions or mutations in genes encoding proteins for surfactant function may cause diffuse lung disease.

Molecular phenotyping and biomarker development: are we on our way towards targeted therapy for severe asthma?

Although different phenotypes of severe asthma can be identified, all are characterized by common symptoms. Due to their heterogeneity, they exhibit differences in pathogenesis, etiology and clinical responses to therapeutic approaches. The identification of distinct molecular phenotypes to define severe asthmatic patients will allow us to better understand the pathophysiology of the disease and thus to more precisely target the treatment for each patient. To achieve this goal, a systematic search for new, reliable and stable biomarkers specific for each phenotype is essential. This review focuses on the current known molecular phenotypes of severe asthma and highlights the need for biomarkers that could (either alone or in combination) be predictive of the treatment outcome.

Biomarkers and severe asthma: a critical appraisal

Severe asthma (SA) is a clinically and etiologically heterogeneous respiratory disease which affects among 5–10 % of asthmatic patients. Despite high-dose therapy, a large patients percentage is not fully controlled and has a poor quality of life. In this review, we describe the biomarkers actually known in scientific literature and used in clinical practice for SA assessment and management: neutrophils, eosinophils, periostin, fractional exhaled nitric oxide, exhaled breath condensate and galectins. Moreover, we give an overview on clinical and biological features characterizing severe asthma, paying special attention to the potential use of these ones as reliable markers. We finally underline the need to define different biomarkers panels to select patients affected by severe asthma for specific and personalized therapeutic approach.