Measurement of fractional exhaled nitric oxide in stable bronchiectasis

Endotypes of Paediatric Cough-Do They Exist and Finding New Techniques to Improve Clinical Outcomes

Chronic cough is a common symptom of many childhood lung conditions. Given the phenotypic heterogeneity of chronic cough, better characterization through endotyping is required to provide diagnostic certainty, precision therapies and to identify pathobiological mechanisms. This review summarizes recent endotype discoveries in airway diseases, particularly in relation to children, and describes the multi-omic approaches that are required to define endotypes. Potential biospecimens that may contribute to endotype and biomarker discoveries are also discussed. Identifying endotypes of chronic cough can likely provide personalized medicine and contribute to improved clinical outcomes for children.

Simultaneous evaluation of the fractional exhaled nitric oxide and blood eosinophil count of T2-high endotype in patients with non-cystic fibrosis bronchiectasis

OBJECTIVE

Recently, a type 2 inflammation (T2) high endotype in bronchiectasis was identified. The fraction of exhaled nitric oxide (FeNO) and blood eosinophil count (BEC) are recognized as representative biomarkers of T2 inflammation. Herein, we investigate the clinical characteristics of T2-high endotype in non-cystic fibrosis bronchiectasis patients classified by FeNO and BEC.

METHODS

This retrospective study included 164 bronchiectasis patients treated in the First Affiliated Hospital of Sun Yat-sen University from December 2017 to July 2022. Clinical characteristics were analyzed after classifying patients into four groups according to T2 inflammation biomarkers (FeNO ≥25 ppb; BEC ≥200/µL).

RESULTS

Among the 164 bronchiectasis patients, 35.3% (58/164) presented with high FeNO, 30.5% (50/164) presented with high BEC, and 10.4% (17/164) had high FeNO and BEC. Patients with high FeNO and low BEC presented with better lung function, fewer affected lobes, and lower dyspnea prevalence compared with the three other groups. Moreover, decreased FeNO, instead of decreased BEC, is revealed to be an independent predictor for disease severity and airflow obstruction in bronchiectasis.

CONCLUSIONS

Simultaneous evaluation of FeNO and BEC proposed different endotypes of bronchiectasis established that patients with low BEC and high FeNO had better lung function, fewer affected lobes, lower dyspnea prevalence, and less disease severity. This result will contribute to a more comprehensive assessment of the disease severity and lead to more precise treatment of T2 inflammation in bronchiectasis patients.

Can Leukotriene Receptor Antagonist Therapy Improve the Control of Patients with Severe Asthma on Biological Therapy and Coexisting Bronchiectasis? A Pilot Study

Introduction: Asthma and bronchiectasis appear to be two related diseases and in their complex inflammatory interaction, the cysteinyl leukotriene/cysteinyl leukotriene receptor 1 (cysLT/cysLTR1) axis appears to play an important role given its involvement also in the neutrophilic pathway. To our knowledge, few studies have been conducted so far to evaluate the role of the leukotriene cysLT/cysLTr1 axis in the management of clinical and inflammatory outcomes within a population of patients with severe asthma and bronchiectasis. The aim of our study was to verify in this population the effect of leukotriene receptor antagonist (LTRA) therapy in clinical and inflammatory control before and after 6 months of introduction of biologic therapy. Methods: We retrospectively enrolled, from eight different severe asthma centers’ outpatients, 36 atopic patients with the simultaneous presence of non-cystic fibrosis (non-CF) and non-allergic bronchopulmonary aspergillosis (non-ABPA) bronchiectasis and severe asthma. The first biological injection was performed at baseline (T0 time). Patients who were already taking LTRA therapy at time T0 were recorded, and no new prescriptions were made. We observed our population over a 6-month period (T1 time). At the baseline we collected the following data: baseline characteristics, clinical history, high resolution computed tomography and bronchiectasis-related parameters and skin prick test. At both times T0 and T1 we collected the following data: asthma control test (ACT), asthma control questionnaire (ACQ), immunoglobulin E (IgE) level, blood count, fractional exhaled nitric oxide 50 (FeNO 50) and flow-volume spirometry. The study was retrospectively registered. Results: Our population had a mean age of 59.08 ± 11.09 and 50% were female. At T1, patients on LTRA therapy had a significantly lower FeNO value (33.03 ± 23.61 vs. 88.92 ± 77.96; p = 0.012). We assessed that the value of ΔFeNO (FeNO 50 T1 − FeNO 50 T0) and the number of unplanned specialist visits allowed a discrimination of 66.7% in the presence of LTRA therapy. We also verified how low FeNO values at time T1 were statistically significant predictors of LTRA therapy (ODD = 9.96 (0.94–0.99); p = 0.032). Conclusion: The presence of LTRA in therapy in a population of severe asthmatics with coexisting non-ASBPA bronchiectasis and non-cystic fibrosis, acting simultaneously on the T helper type 2 (TH2) pathway and probably on the neutrophilic component of bronchiectasis, would allow a further amplification of the beneficial effects of biological therapy, leading to a reduction in the number of unplanned visits to specialists.

Clinical features associated with a doctor-diagnosis of bronchiectasis in the Severe Asthma Network in Italy (SANI) registry

BACKGROUND

Several severe asthma comorbidities have been identified: an emerging one is bronchiectasis. We evaluated the frequency of bronchiectasis on severe asthma in a real-life setting, through the 'Severe Asthma Network Italy' (SANI) registry.

METHODS

SANI registry encompasses demographic, clinical, functional and inflammatory data of Italian severe asthmatics. Data obtained by the enrolled patients were analyzed, focusing the attention on those patients with concomitant clinically relevant bronchiectasis.

RESULTS

About 15.5% patients have bronchiectasis. Bronchiectasis diagnosis was associated with a higher prevalence of chronic rhinosinusitis with nasal polyps (54.6% vs. 38%, p = 0.001) and higher serum IgE levels (673.4 vs. 412.1 kUI/L, p = 0.013). Patients with bronchiectasis had worse asthma control (ACT: 16.7 vs 18.2, p = 0.013), worse quality of life (AQLQ: 4.08 vs. 4.60, p = 0.02) and lower lung function (FEV₁% predicted 67.3 vs. 75.0, p = 0.002). A higher rate of severe asthma exacerbations in the previous 12 months (85.2% vs. 61.5%, p < 0.001) was found in patients with bronchiectasis.

CONCLUSION

severe asthma associated with bronchiectasis represents a particularly severe asthma variant, possibly driven by an eosinophilic endotype. We, therefore, suggest that bronchiectasis should necessarily be assessed in severe asthmatic patients.

Fraction of Exhaled Nitric Oxide Is Elevated in Patients With Stable Chronic Obstructive Pulmonary Disease: A Meta-analysis

BACKGROUND

Fraction of exhaled nitric oxide (FeNO) is a noninvasive indicator of eosinophilic airway inflammation and has been used for the diagnosis and treatment of asthma. The levels of FeNO are controversial in patients with stable chronic obstructive pulmonary disease (COPD). Accordingly, this study aimed to assess FeNO levels in patients with stable COPD.

MATERIALS AND METHODS

A search of the Medline, Embase, Web of Science, ClinicalTrials.gov and The Cochrane Library databases was performed in August 2019. The literature search was restricted to articles published in English. Studies were included if they reported data addressing FeNO levels in patients with stable COPD and healthy controls. Review Manager version 5.3 (The Nordic Cochrane Centre, The Cochrane Collaboration, Copenhagen, Denmark) was used for meta-analysis.

RESULTS

A total of 19 studies were included. Analysis revealed that FeNO levels in patients with stable COPD were higher than those in the healthy control group (mean difference [MD] 2.49 [95% confidence interval {CI} 0.99-4.00]; P < 0.05), those in nonsmoking patients with stable COPD were higher than those in the healthy control group (MD 5.04 [95% CI 2.19-7.89]; P < 0.05) and those in smoking patients with stable COPD were not higher than those in the healthy control group (MD 0.30 [95% CI -2.81 to 3.41]; P = 0.85). FeNO measured using a chemiluminescence analyzer in nonsmoking patients with stable COPD was higher than those in the healthy control group (MD 4.84 [95% CI 1.83-7.86]; P < 0.05).

CONCLUSIONS

Findings suggested that FeNO levels in patients with stable COPD were elevated, and that smokers exhibited decreased levels.

Factors associated with bronchiectasis in patients with uncontrolled asthma; the NOPES score: a study in 398 patients

Background

Some studies have reported a high prevalence of bronchiectasis in patients with uncontrolled asthma, but the factors associated with this condition are unknown. The objective of this study was to determine the prevalence of bronchiectasis in uncontrolled moderate-to-severe asthma and to identify risk factors and their correlation with bronchiectasis in these patients.

Methods

This is a prospective study of data from consecutive patients with uncontrolled moderate-to-severe asthma. Diagnosis of bronchiectasis was based on high-resolution computed tomography. A prognostic score was developed using a logistic regression model, which was used to determine the factors associated with bronchiectasis.

Results

A total of 398 patients (60% with severe asthma) were included. The prevalence of bronchiectasis was 28.4%. The presence of bronchiectasis was associated with a higher frequency of chronic expectoration (OR, 2.95; 95% CI, 1.49–5.84; p = 0.002), greater severity of asthma (OR, 2.43; 95% CI, 1.29–4.57; p = 0.006), at least one previous episode of pneumonia (OR, 2.42; 95% CI, 1.03–5.69; p = 0.044), and lower levels of FeNO (OR, 0.98; 95% CI, 0.97–0.99; p = 0.016). The NOPES score was developed on the basis of these variables (FeNO[cut off point 20.5 ppb], Pneumonia, Expectoration and asthma Severity), and it ranges from 0 to 4 points, where 0 means “no risk” and 4 corresponds to “high risk”. The NOPES score yielded an AUC-ROC of 70% for the diagnosis of bronchiectasis, with a specificity of 95%.

Conclusions

Almost a third of the patients with uncontrolled moderate-to-severe asthma had bronchiectasis. Bronchiectasis was related to the severity of asthma, the presence of chronic expectoration, a previous history of pneumonia, and lower levels of FeNO. The NOPES score is an easy-to-use scoring system with a high prognostic value for bronchiectasis in patients with uncontrolled moderate-to-severe asthma.

The role of non-invasive modalities for assessing inflammation in patients with non-cystic fibrosis bronchiectasis

INTRODUCTION

Bronchiectasis is a heterogeneous entity, taking into account clinical characteristics, inflammatory response, effectiveness of treatment and frequency of exacerbations. In stable state non-cystic fibrosis (non-CF) bronchiectasis, little is known about non-invasive techniques used for evaluating airway inflammation in obstructive airway diseases.

OBJECTIVES

We sought to evaluate the associations between induced sputum and clinical/radiologic characteristics, and the differences between biomarkers expressing Th1 and Th2 response in patients with non-CF bronchiectasis and to compare our findings with a previously studied population of patients with asthma and COPD.

METHODS

We evaluated prospectively collected data from subjects with bronchiectasis. Comparisons were made between clinical, radiographic and physiologic characteristics, as well as induced sputum markers using appropriate statistical tools. We compared the levels of sputum markers with those of a previously studied cohort of asthma and COPD patients.

RESULTS

We enrolled 40 subjects (21men, mean age 63.5yrs) with bronchiectasis. Fifteen subjects (37.5%) had a neutrophilic phenotype, 7 (17.5%) had an eosinophilic phenotype, 3 (12.5%) had a mixed neutrophilic-eosinophilic phenotype and 15 (37.5%) had a paucigranulocytic phenotype. Subjects with sputum neutrophilia had more severe bronchiectasis in HRCT and higher levels of IL-8 in sputum, whereas subjects with eosinophilia had higher levels of FeNO, greater bronchodilator reversibility and higher sputum IL-13. Sputum IL-8 levels were higher in subjects exhibiting frequent exacerbations and correlated with neutrophils in sputum (r=0.799), the extent of bronchiectasis in HRCT (r=0.765) and post-bronchodilator FEV₁ (r=-0.416). Sputum IL-13 levels correlated with sputum eosinophils (r=0.656) and bronchodilator reversibility (r=0.441). Neutrophilic bronchiectasis exhibited comparable IL-8 levels to COPD, whereas eosinophilic bronchiectasis showed significantly lower IL-13 levels compared to asthma.

CONCLUSIONS

Sputum cell counts and IL-8 and IL-13 correlate with distinct clinical and functional measurements of disease severity and therefore may have a role for non-invasively assessing inflammation in non-cystic fibrosis bronchiectasis.

Importance of fractional exhaled nitric oxide in diagnosis of bronchiectasis accompanied with bronchial asthma

BACKGROUND

Fractional exhaled nitric oxide (FeNO) measurement is a simple, rapid, highly reproducible, and noninvasive method of airway inflammation assessment. Therefore, FeNO is extensively used for the diagnosis and management of asthma. The feasibility of using FeNO as an alternative to conventional pulmonary function test to differentiate patients with bronchiectasis (BE) and bronchial asthma from those with BE only remains unclear.

METHODS

From February 2013 to February 2015, 99 patients diagnosed with BE through high-resolution computed tomography (HRCT) were subjected to FeNO measurement, bronchial challenge test (BCT), or bronchodilator test. Bronchial hyperreactivity and/or reversible airway obstruction was used to define asthma. The receiver operating characteristic (ROC) curves were obtained to elucidate the clinical functions of FeNO in the diagnosis of asthmatic patients with BE, and the optimal operating point was also determined.

RESULTS

Of 99 patients with BE, 20 patients presented asthma, and 12 of these patients received regular treatment, which were given with budesonide (200 µg, bid) for 12 weeks to evaluate changes in the concentration and assess the role of FeNO in the treatment. The area under the ROC curve was estimated as 0.832 for FeNO. Results also revealed a cut off value of >22.5 part per billion (ppb) FeNO for differentiating asthmatic from non-asthmatic (sensitivity, 90.0%; specificity, 62.5%) patients with BE. FeNO and forced expiratory volume for 1 second significantly improved after the treatment.

CONCLUSIONS

Clinical FeNO measurement is a simple, noninvasive, and rapid method used to differentiate asthmatic from nonasthmatic patients with BE. This technique exhibits potential for asthma management.

The role of fractional exhaled nitric oxide in asthma management

Measuring fractional exhaled nitric oxide (FeNO) is a relatively new option for assessing allergic inflammation in the lungs. Clinical management of asthma is challenging, and measuring exhaled nitric oxide can provide another type of data to assist in meeting this challenge. FeNO is easy to perform, and the equipment is not forbiddingly expensive. FeNO provides a complement to traditional measures of asthma control and can help guide diagnostic and treatment choices. This article explains what it is, how the measurements are performed, what the norms are, and its use and limitations in the management of asthma.

Significance of fractional exhaled nitric oxide in chronic eosinophilic pneumonia: a retrospective cohort study

Background

Chronic eosinophilic pneumonia (CEP) is characterized by chronic eosinophilic infiltration of the lung. It is dramatically responsive to corticosteroid treatment, but symptoms and radiopacities recur frequently after tapering or discontinuing the medication. Fractional exhaled nitric oxide (FeNO) is a well-known noninvasive marker of eosinophilic airway inflammation. The aim of this retrospective cohort study was to investigate the relationships of FeNO with peripheral eosinophilia and the clinical state of CEP and its validity for predicting exacerbation of CEP.

Methods

Standard clinical and laboratory parameters, peripheral eosinophil percentage and count, and FeNO level were measured in 18 patients with CEP at several assessment points over 1 year.

Results

FeNO level was positively correlated with peripheral eosinophil count (r = 0.341, P = 0.005) and percentage (r = 0.362, P = 0.003). The median (IQR) FeNO levels were 79 (41–88) and 35 (26–49) ppb in uncontrolled (13/74 measurements) and controlled (61/74 measurements) CEP, respectively (P = 0.010). The FeNO level of 66.0 ppb showed the largest area under the curve (0.835) for predicting exacerbation of CEP (sensitivity = 0.80, specificity = 0.84).

Conclusion

FeNO may be useful for monitoring eosinophilic parenchymal inflammation and determining the appropriate corticosteroid dose in CEP.

Neutrophil elastase gene polymorphisms: modulators of response to therapy in childhood bronchiectasis?

BACKGROUND

The aim of this study was to investigate polymorphisms in the promoter region of the neutrophil elastase (ELANE) gene as potential modulators of the therapeutic response in children with idiopathic bronchiectasis.

METHODS

The study included 48 children between 5 and 17 years old who were diagnosed with idiopathic bronchiectasis based on high-resolution computed tomography of the thorax. In all patients therapy included administration of antibiotics, anti-inflammatory drugs, expectorants, and postural drainage. Response to therapy was evaluated by the change in FeNO levels before and after administration of therapy. The ELANE promoter region polymorphisms were analyzed by PCR-direct DNA sequencing.

RESULTS

According to the predicted activity of ELANE genotypes, subjects were divided into two groups: low/intermediate activity (n = 18) and high activity (n = 30). Subjects in the group with high-activity genotype had higher initial FeNO levels and this difference was statistically significant (t = 2.906; p = 0.006). The difference between FeNO levels before and after therapy was also statistically significantly higher in children with high-activity genotype (t = 3.329; p = 0.002). Statistically significant correlation was observed between the change in FeNO levels and ELANE genotypes (r = 0.350; p = 0.015).

CONCLUSION

Children with high-activity genotype had higher initial FeNO levels and showed better response to therapy than children with low/intermediate-activity genotypes.