Relationship between Fractional Exhaled Nitric Oxide Level and Efficacy of Inhaled Corticosteroid in Asthma-COPD Overlap Syndrome Patients with Different Disease Severity

Inhaled corticosteroids in asthma and chronic obstructive pulmonary disease combined phenotype: when to use and what to expect?

The term "asthma-chronic obstructive pulmonary disease (COPD) combined phenotype" describes patients with persistent airflow limitation and features of both asthma and COPD. There is a lack of data on effective treatments for this group, often excluded from asthma or COPD trials. Inhaled corticosteroids (ICS) are standard for asthma, while bronchodilators are key for COPD. This study is a prospective interventional study that included 43 patients diagnosed with the asthma-COPD overlap phenotype, as per Sin et al. criteria, who were treated as COPD priorly and followed over one year. These patients received additional treatment with a moderate-dose ICS metered dose inhaler beclamethasone 800 mcg daily, in addition to their optimal inhaled bronchodilator therapy. Follow-up spirometry along with reversibility, fractional exhaled nitric oxide (FeNO), blood investigations like total eosinophil count (TEC) and immunoglobulin E (IgE) were done; sputum eosinophils were measured, and a history of exacerbations was noted. These parameters were compared with baseline values obtained prior to the initiation of ICS to evaluate the impact of the intervention. Among the 43 individuals in the study population, the majority fell within the age group of 60-69 years. The addition of ICS to bronchodilators over a one-year period resulted in significant improvements in their forced expiratory volume in one second. Additionally, there was a notable reduction in the FeNO level, along with decreases in the TEC, serum IgE levels, and sputum eosinophils. Although the number of exacerbations decreased during the study period in this subgroup, this reduction did not reach statistical significance. Based on these findings, the study suggests that ICS should be considered as an adjunct to inhaled bronchodilators for the management of stable COPD patients exhibiting features of the asthma-COPD combined phenotype.

Relationship between fraction of exhaled nitric oxide and peripheral eosinophilia in asthma

BACKGROUND

Achieving disease control is the goal of asthma management. Serum or sputum eosinophil counts have been known traditional means of assessing eosinophilic airway inflammation in asthma, which is vital in predicting response to corticosteroid therapy which ultimately promotes control of the disease. Evidence suggests that fraction of exhaled nitric oxide (FeNO) may be a more useful non-invasive surrogate biomarker for the assessment of eosinophilic airway inflammation and could help with the timely adjustment of inhaled corticosteroid therapy in the uncontrolled asthma patient. The relationship between FeNO and other markers of airway inflammation has been variable in literature, with limited data in sub-Saharan Africa where FeNO testing is very sparse. We sought to define the relationship between FeNO levels, serum eosinophil counts, spirometry measures and symptom control among asthma patients.

MATERIALS AND METHODS

The study was conducted at the Asthma Clinic of a large tertiary hospital. This study included 82 patients with physician-diagnosed asthma being regularly managed at the clinic. All participants were taken through the asthma control test (ACT), had FeNO and spirometry measurements taken according to the American Thoracic Society (ATS) guidelines. Blood samples were obtained from all participants for serum eosinophil counts. Correlation coefficient was used to ascertain the relationship between FeNO levels and serum eosinophil counts, ACT scores, and spirometry measurements. Logistic regression was used to examine the association between high FeNO and abnormal FEV1 percentage predicted (<80%) with adjustments for age, sex, and BMI.

RESULTS

A total of 82 patients with asthma were included in the study, with higher prevalence of females (72%). Majority (40.2%) of the patients were found in the 60 and above age category. The median FeNO level and ACT score was 42.00 (26.00-52.50) parts per billion (ppb) and 20.0 (18-23) respectively. The median serum eosinophil counts was 0.25(0.90-0.38) × 109/L. The median FeNO levels were significantly higher in patients with partly and very poorly controlled asthma than in the well-controlled group (p < 0.001). A total of 47(57%) of the patients were classified as having well controlled asthma and 35 (42%) uncontrolled. FeNO correlated with serum eosinophil counts (r = 0.450, p < 0.001), ACT (r = -0.648, p < 0.001), and FEV1 percentage predicted (r = -0.353, p = 0.001). High FeNO (>50 ppb) was associated with an over fivefold increased risk of having an abnormal FEV1 percentage predicted.

CONCLUSION

FeNO levels significantly correlated with the ACT scores, serum eosinophil counts and FEV1% predicted among the asthma patients who were on inhaled corticosteroid therapy. High FeNO was significantly associated with abnormal FEV1 percentage predicted. We suggest that the point of care assessment of FeNO is a reliable marker of eosinophilic inflammation in our cohort of patients and together with 'ACT scores' in our asthma clinics could increase asthma control rates.

Clinical value of Vitamin-D combined with budesonide/formoterol and theophylline sodium glycinate sustained-release tablets in the treatment of chronic obstructive pulmonary disease patients

Objective

To explore the clinical value of Vitamin-D combined with budesonide/formoterol (BF) and theophylline sodium glycinate (TSG) sustained-release tablets in the treatment of patients with chronic obstructive pulmonary disease (COPD).

Methods

Medical records of 114 patients with CODP, treated in Wenzhou Geriatric Hospital from October 2020 to February 2023, were retrospectively analyzed. Of them, 59 received treatment with Vitamin-D combined with BF and TSG sustained-release tablets (Group-A), and 55 patients received treatment with BF combined with TSG sustained-release tablets (Group-B). Lung function indicators, blood gas status, inflammatory factors, fractional exhaled nitric oxide (FeNO), and 25-hydroxyvitamin D [25(OH)D] levels before and after the treatment in both groups were collected.

Results

After the treatment, lung function indicators, blood gas status, inflammatory factors, FeNO, and 25 (OH) D levels in both groups were significantly improved compared to pretreatment levels, and were significantly better in the Group-A compared to Group-B (P<0.05).

Conclusions

The combination of Vitamin-D, BF, and TSG sustained-release tablets can effectively regulate the blood gas status of patients with COPD, improve lung function, regulate FeNO and 25 (OH) D, and effectively downregulate the levels of inflammatory factors, thus reducing the degree of inflammatory response.

The Relationship of Fractional Exhaled Nitric Oxide in Patients with AECOPD

Objective

To identify the relationship between patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and their fractional-exhaled nitric oxide (FeNO) levels.

Methods

Patients diagnosed with AECOPD in the respiratory department of Beijing Chaoyang Hospital from June 2017 to August 2019 were recorded. The demographic data, FeNO value, peripheral blood eosinophil count, number of acute exacerbations in the past year, pulmonary function test, use of inhaled glucocorticoids (ICS) and other data were collected and analyzed. FeNO was measured again three months after discharge, the participants were assessed to determine if the stable period criteria were met.

Results

A total of 214 patients met the requirements of this study. 25ppb for FeNO was used as the cutoff for further analysis. The proportion of males, number of acute exacerbations in the past year, number of ICS users, leukocyte count and eosinophil count in the high FeNO-level group was significantly higher than that in the low-level group (P < 0.05). The results showed that the number of acute exacerbations in the past year, number of ICS users, and eosinophil count were statistically significant in the model (P < 0.05). The study also showed that the level of FeNO in the acute exacerbation phase was significantly higher than that in the stable phase. The ROC curve that the area under the curve used by FeNO to predict ICS used is 0.631 (95% CI: 0.526-0.736), and the corresponding P value is 0.022.

Conclusion

FeNO is closely related to activated T2 inflammation and eosinophil count in COPD patients. The FeNO levels can be used as an index to evaluate the severity of COPD and predict the recovery of activity after ICS treatment. FeNO can predict the use of ICS and is a beneficial supplement to eosinophils.

Comparison of health-related quality of life measures in asthma-COPD overlap

OBJECTIVE

The Asthma Quality of Life Questionnaire (AQLQ) and COPD assessment test (CAT) are used to assess the health status of asthma and chronic obstructive pulmonary disease (COPD), respectively. However, whether these questionnaires are appropriate in patients with asthma-COPD overlap (ACO) has not been reported. This study aimed to evaluate the performance of the AQLQ and CAT in subjects with ACO.

METHODS

Subjects were enrolled from two previously described observational studies in Beijing, China. ACO was defined by a consensus definition from a roundtable discussion. All subjects completed the AQLQ, CAT, St George's Respiratory Questionnaire (SGRQ), pulmonary function tests, and the Asthma Control Questionnaire (ACQ)-5. Cross-sectional construct validity was evaluated by correlating the AQLQ and CAT with SGRQ score and other measures of asthma and COPD severity.

RESULTS

147 subjects with ACO were recruited. There were floor effects on non-respiratory components of the CAT, and ceiling effects on emotion domains of the AQLQ. Both questionnaires were significantly correlated with ACQ-5 score but were not correlated with FEV1% predicted or FVC% predicted. The AQLQ and CAT were strongly correlated with SGRQ score (r = -0.657 and r = 0.623, respectively). Multivariable linear regression analysis showed that the AQLQ (standardized β-coefficient = -0.449, p < .001) had a stronger association with SGRQ score compared with CAT (standardized β-coefficient = 0.211, p = .023).

DISCUSSION

The AQLQ and CAT were both valid for assessing the health-related quality of life in subjects with ACO, but the AQLQ performed better than CAT.

Variability of fractional exhaled nitric oxide is associated with the risk and aetiology of COPD exacerbations

BACKGROUND AND OBJECTIVE

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are heterogeneous in aetiology and accelerate disease progression. Here, we aimed to investigate the association of fractional exhaled nitric oxide (FeNO) and its variability with AECOPD of different aetiology.

METHODS

FeNO was determined in 2157 visits (1697 stable, 133 AECOPD and 327 follow-up) of 421 COPD patients from the PREVENT study, an investigator-initiated, longitudinal and interventional study, who were on daily treatment with inhaled corticosteroids/long-acting β2-agonists.

RESULTS

Longitudinal measurements of FeNO revealed an intra-subject variability of FeNO that was significantly higher in exacerbators compared to non-exacerbators (p < 0.001) and positively associated with the number of AECOPD. As FeNO variability increased, the probability of patients to remain AECOPD-free decreased. In patients included in the highest FeNO variability quartile (≥15.0 ppb) the probability to remain free of AECOPD was only 35% as compared to 80% for patients included in the lowest FeNO variability quartile (0.50-4.39 ppb). The change of FeNO from the last stable visit to AECOPD was positively associated with the probability of viral infections and this association was stronger in current smokers than ex-smokers. In contrast, the change in FeNO from the last stable visit to an AECOPD visit was inversely associated with the probability of bacterial infections in ex-smokers but not in current smokers.

CONCLUSION

FeNO variability was associated with the risk and aetiology of AECOPD differentially in current and ex-smokers.

Short- and medium-term effect of inhaled corticosteroids on exhaled breath biomarkers in severe asthma

BACKGROUND

Inhaled corticosteroids (ICS) are the mainstay of therapy in asthma, but benefits vary due to disease heterogeneity. Steroid insensitivity is a particular problem in severe asthma, where patients may require systemic corticosteroids and/or biologics. Biomarkers sensitive to ICS over a short period of time could inform earlier and more personalised treatment choices.

OBJECTIVE

To investigate how exhaled breath biomarkers change over two-hours and one-week following monitored ICS dosing in severe asthma patients with evidence of uncontrolled airway inflammation.

METHOD

Patients with severe asthma and elevated FeNO (≥45ppb, indicative of active airway inflammation) were recruited. Exhaled breath biomarkers were evaluated using fractional exhaled nitric oxide (FeNO), exhaled breath temperature (EBT), particles in exhaled breath (PExA) and volatile organic compounds (VOCs). Samples were collected over 2 hrs following observed inhalation of 1000mcg fluticasone propionate, and at a second visit 1 week after taking the same dose daily via an inhaler monitoring device that recorded correct actuation and inhalation. Changes in parameters over 2 hrs were analysed by the Friedman test and 1 week by Wilcoxon's test (p-value for significance set at 0.05; for VOCs false discovery rate q of 0.1 by Benjamini-Hochberg method applied).

RESULTS

17 participants (9 male) were recruited with median (IQR) age 45 (36-59) yrs. EBT (p<0.05) and levels of six VOCs (q<0.1) fell over the 2 hrs after high dose ICS; there were no changes in FeNO or PEXA. After one week of using high dose ICS, there were falls in FeNO, EBT and two VOCs (p<0.05), but no changes in PEXA.

CONCLUSION

Reduction in exhaled breath temperature over the short and medium term after high dose ICS may reflect airway vascular changes, and this, together with the observed changes in exhaled VOCs, merits further investigation as potential markers of inhaled corticosteroid use and effectiveness.

A genomic approach identifies sRAGE as a putatively causal protein for asthma

BACKGROUND

Asthma is a complex respiratory condition caused by environmental and genetic factors. Although lower concentrations of the anti-inflammatory protein sRAGE have been associated with asthma in humans and mouse models, it is uncertain whether sRAGE plays a causal role in asthma.

OBJECTIVE

We designed a two-stage study of sRAGE in relation to asthma with i) association analysis in FHS participants and ii) causal inference testing using MR.

METHODS

We measured plasma levels of sRAGE and performed cross-sectional analysis to examine the association between plasma sRAGE concentration and asthma status in 6,546 FHS participants. We then used sRAGE pQTLs derived from a GWAS of plasma sRAGE levels in ∼7,000 FHS participants with UK Biobank asthma GWAS in MR to consider sRAGE as a putatively causal protein for asthma. We also performed replication MR using an externally-derived sRAGE pQTL from the INTERVAL study. Last, we conducted colocalization using cis-pQTL variants at the AGER locus with variants from the UK Biobank asthma GWAS.

RESULTS

Association analysis revealed that each 1 SD increment in sRAGE concentration was associated with a 14% lower odds of asthma in FHS participants (95% CI 0.76-0.96). MR identified sRAGE as putatively causal for and protective against asthma based on self-reported (OR [per 1 SE increment in inverse rank-normalized sRAGE]=0.97, 95% CI 0.95-0.99; p=0.005) and doctor-diagnosed asthma (OR=0.97, 95% CI 0.95-0.99; p=0.011).

CONCLUSION

Through this genomic approach, we identified sRAGE as a putatively causal, biologically important, and protective protein in relation to asthma. Functional studies in cell/animal models are needed to confirm our findings.

Asthma-COPD Overlap: What Are the Important Questions?

Asthma-COPD overlap (ACO) is a heterogeneous condition that describes patients who show persistent airflow limitation with clinical features that support both asthma and COPD. Although no single consensus definition exists to diagnose this entity, common major criteria include a strong bronchodilator reversibility or bronchial hyperreactivity, a physician diagnosis of asthma, and a ≥ 10-pack-year cigarette smoking history. The prevalence of ACO ranges from 0.9% to 11.1% in the general population, depending on the diagnostic definition used. Notably, patients with ACO experience greater symptom burden, worse quality of life, and more frequent and severe respiratory exacerbations than those with asthma or COPD. The underlying pathophysiologic features of ACO have been debated. Although emerging evidence supports the role of environmental and inhalational exposures in its pathogenesis among patients with a pre-existing airway disease, biomarker profiling and genetic analyses suggest that ACO may be a heterogeneous condition, but with definable characteristics. Early-life factors including childhood-onset asthma and cigarette smoking may interact to increase the risk of airflow obstruction later in life. For treatment options, the population with ACO historically has been excluded from therapeutic trials; therefore strong, evidence-based recommendations are lacking beyond first-line inhaler therapies. Advanced therapies in patients with ACO are selected according to disease phenotypes and are based on extrapolated data from asthma and COPD. Research focused on defining biomarkers and evidence-based treatment options for ACO is needed urgently.

Asthma-COPD overlap: current understanding and the utility of experimental models

Pathological features of both asthma and COPD coexist in some patients and this is termed asthma-COPD overlap (ACO). ACO is heterogeneous and patients exhibit various combinations of asthma and COPD features, making it difficult to characterise the underlying pathogenic mechanisms. There are no controlled studies that define effective therapies for ACO, which arises from the lack of international consensus on the definition and diagnostic criteria for ACO, as well as scant in vitro and in vivo data. There remain unmet needs for experimental models of ACO that accurately recapitulate the hallmark features of ACO in patients. The development and interrogation of such models will identify underlying disease-causing mechanisms, as well as enabling the identification of novel therapeutic targets and providing a platform for assessing new ACO therapies. Here, we review the current understanding of the clinical features of ACO and highlight the approaches that are best suited for developing representative experimental models of ACO.

Understanding the pathogenesis of asthma-COPD overlap is critical for improving therapeutic approaches. We present current knowledge on asthma-COPD overlap and the requirements for developing an optimal animal model of disease.https://bit.ly/3lsjyvm

Asthma-Chronic Obstructive Pulmonary Disease Overlap

Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) defines a subgroup of patients with asthma who have persistent airflow obstruction or patients with COPD who may exhibit variable airflow limitation and/or evidence of type 2 inflammation. Additional investigations are needed to determine whether ACO represents a distinct disorder with unique underlying pathophysiology, whether ACO patients should be managed differently from those with asthma or COPD, and whether the diagnosis affects long-term outcomes. This article presents the data about the clinical features of ACO, the current information regarding the underlying pathophysiology of the syndrome, and current understanding of therapeutic options.

Role of Type2 Inflammatory Biomarkers in Chronic Obstructive Pulmonary Disease

Airway inflammation in chronic obstructive pulmonary disease (COPD) is typically thought to be driven by Type1 immune responses, while Type2 inflammation appears to be present in definite proportions in the stable state and during exacerbations. In fact, some COPD patients showed gene expression of Type2 inflammation in the airway, and this subset was associated with the inhaled corticosteroid (ICS) response. Interestingly enough, the relationship between COPD and diseases associated with Type2 inflammation from the perspective of impaired lung development is increasingly highlighted by recent epidemiologic studies on the origin of COPD. Therefore, many researchers have shown an interest in the prevalence and the role of existent Type2 biomarkers such as sputum and blood eosinophils, exhaled nitric oxide fraction, and atopy, not only in asthma but also in COPD. Although the evidence about Type2 biomarkers in COPD is inconsistent and less robust, Type2 biomarkers have shown some potential when analyzing various clinical outcomes or therapeutic response to ICS. In this article, we review the existent and emerging Type2 biomarkers with clinically higher applicability in the management of COPD.

Fractional Exhaled Nitric Oxide as an Inflammatory Biomarker in Chronic Obstructive Pulmonary Disease (COPD) with or without Concurrent Diagnosis of Asthma: The Canadian Cohort Obstructive Lung Disease (CanCOLD)

We studied whether fractional exhaled nitric oxide (F _ENO) can differentiate chronic obstructive pulmonary disease (COPD) with concurrent diagnosis of asthma from COPD-only as well as its ability to predict disease severity and progression. This study was embedded in the Canadian Cohort Obstructive Lung Disease (CanCOLD). Subjects of ≥40 years old completed F _ENO measurements were subdivided into four groups, including COPD (N = 86 [COPD-only (N = 35) and COPD with concurrent diagnosis of asthma (N = 51)], healthy (N = 72), and at risk (N = 151). Three of the most common clinical definitions were used for characterizing COPD with concurrent diagnosis of asthma: 1) atopy and self-reported physician diagnosis of asthma, 2) ≥12% and ≥200 ml post-bronchodilator FEV1; 3) self-reported physician diagnosis of asthma. F _ENO values were classified using quartiles and the American Thoracic Society (ATS) guideline 2011. Compared to COPD-only, more COPD with concurrent diagnosis of asthma had a significant F _ENO50 level of [Formula: see text] 33.5 ppb (fourth quartile) than COPD-only (p = 0.045, 0.011, and 0.006, for definition 1, 2, and 3, respectively). Considering the ATS guideline 2011, fewer COPD with concurrent diagnosis of asthma had F _ENO50 < 25 than COPD-only, which was statistically significant with definition 1 and 3 (p = 0.038 and 0.026, respectively). F _ENO as a biomarker has the potential to be used as a complementary value for differentiating COPD with concurrent diagnosis of asthma from COPD-only. Further studies should be conducted on validated definitions of COPD with concurrent diagnosis of asthma, which may include a reference to the type of airway inflammation in addition to the clinical definition.

Clinical Features of Chronic Obstructive Pulmonary Disease with High Fractional Exhaled Nitric Oxide

Background

The fractional exhaled nitric oxide (FENO) test is useful in asthma patients. However, a few studies on its usefulness in chronic obstructive pulmonary disease (COPD) patients have been reported. We analyzed the FENO level distribution and clinical characteristics according to the FENO level in COPD patients.

Methods

From December 2014 to June 2019, COPD patients who underwent pulmonary function and FENO tests at Chonnam National University Hospital were retrospectively evaluated for FENO, comorbidities, asthma history, blood eosinophil, and pulmonary function test. The high FENO group was defined as those with FENO level>25 parts per billion (ppb).

Results

A total of 849 COPD patients (mean age, 70.3±9.4 years) were included. The mean forced expiratory volume at 1 second was 66.5±21.7% and the mean FENO level was 24.3±20.5 ppb. Patients with FENO ≤25 ppb were 572 (67.4%) and those with FENO >25 ppb were 277 (32.6%). Blood eosinophil percentage was significantly higher (4.2±4.8 vs. 2.7±2.5, p<0.001) in patients with the high FENO group than the low FENO group. The high FENO group revealed a significantly higher frequency of patients with blood eosinophil percentage >3% (46.9% vs. 34.8%, p=0.001) and asthma history (25.6% vs. 8.6%, p<0.001) than the lower FENO group. Asthma history, blood eosinophil percentage >3%, and positive bronchodilator response (BDR) were independent risk factors for the high FENO level (adjusted odds ratio [aOR], 3.85; p<0.001; aOR, 1.46; p=0.017; and aOR, 1.57, p=0.034, respectively) in the multivariable analysis.

Conclusion

The FENO level distribution varied in COPD patients and the mean FENO value was slightly elevated. Asthma history, eosinophil percent, and positive BDR were independent risk factors for the high FENO level.

[Correlation between expressions of myeloperoxidase and eosinophil cationic protein in sputum and clinical features of asthma-chronic obstructive pulmonary disease overlap]

OBJECTIVE

To observe the role of myeloperoxidase(MPO)and eosinophilic cationic protein(ECP)in the airway inflammation and their correlation with clinical feature in asthma-COPD overlap (ACO) patients.

METHODS

Twenty patients with COPD, 20 with asthma, 20 with ACO and 20 control subjects underwent pulmonary function test for measurement of forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC), peak expiratory flow (PEF), and maximum midexpiratory flow (MMF_25/75). COPD assessment test (CAT) was used to evaluate the clinical symptoms of the patients with COPD and ACO. The asthma control test (ACT) was used to evaluate the asthma control in the patients with asthma and ACO. Induced sputum samples were collected from the subjects for analysis of neutrophil and eosinophil ratios, and enzyme-linked immunosorbent assay was used to determine the expression levels of MPO and ECP in the sputum.

RESULTS

No significant difference was observed in the CAT scores between ACO group and COPD group (P&gt; 0.05). Compared with the asthma group, the patients with ACO had significantly lower ACT scores and lower FEV₁, PEF and MMF_25/75 (P &lt; 0.05). The patients with ACO had significantly higher FVC and sputum eosinophil ratio than those with COPD (P &lt; 0.05), and a higher sputum neutrophil ratio than those with asthma (P &lt; 0.01). In ACO group, the MPO level in sputum was significantly higher than that in the asthma group (P &lt; 0.05), while sputum ECP level was significantly higher than that in both the asthma group and COPD group (P &lt; 0.05 or 0.01). In ACO group, sputum MPO level was positively correlated with sputum neutrophil ratio (r=0.8358, P &lt; 0.01) but was not correlated with CAT score or FEV₁ (P&gt; 0.05); sputum ECP level was positively correlated with sputum eosinophil ratio (r=0.4666, P &lt; 0.05) and was inversely correlated with ACT score (r=-0.4966, P &lt; 0.05) and FEV₁ (r=-0.4610, P &lt; 0.05).

CONCLUSIONS

Both neutrophilic and eosinophilic inflammations occur in the airway of patients with ACO, and their sputum ECP level is negatively correlated with asthma control and obstructive airflow limitation.

Challenges in the management of asthma associated with smoking-induced airway diseases

INTRODUCTION

Smoking-induced airway diseases such as chronic bronchitis, emphysema, and small airway dysfunction contribute to the chronic respiratory symptoms experienced by adults with asthma, including those with spirometric chronic obstructive pulmonary disease (COPD), termed asthma-COPD overlap (ACO). Drug treatment of symptomatic smokers with asthma or ACO is uncertain due to their exclusion from most clinical trials.

AREAS COVERED

This review summarizes evidence for the efficacy of small molecule drugs used in the clinic to treat current and former smokers with a diagnostic label of asthma or ACO. Other therapeutic interventions are reviewed, including smoking cessation and biologics.

EXPERT OPINION

Clinical trials and observational studies suggest that smoking cessation and approved drugs used to treat non-smokers with asthma produce clinical benefits in smokers with asthma or ACO, although the overall quality of evidence is low. The efficacy of some treatments for asthma is altered in current smokers, including reduced responsiveness to short-term inhaled corticosteroids and possibly improved responsiveness to leukotriene receptor antagonists. Preliminary findings suggest that low-dose theophylline, statins, and biologics, such as omalizumab, mepolizumab, and dupilumab, may improve clinical outcomes in smokers with asthma or ACO. Improved phenotyping and endotyping of asthma and smoking-induced airway diseases should lead to better targeted therapies.

Investigating Fractional Exhaled Nitric Oxide in Chronic Obstructive Pulmonary Disease (COPD) and Asthma-COPD Overlap (ACO): A Scoping Review

Chronic obstructive pulmonary disease (COPD) is the most common fixed airflow limitation. Individuals may present with the features of both asthma and COPD called asthma-COPD overlap (ACO) with more severity and worse health-related quality of life than COPD or asthma. One of the promising biomarkers that could be used in clinical practice to differentiate ACO from COPD is fractional exhaled nitric oxide (FENO). The role of Fractional exhaled nitric oxide (FENO) in COPD/ACO remains unknown. This scoping review aims to investigate the role of FENO measurement to differentiate COPD from ACO, to anticipate disease severity/progression and treatment response. A structured comprehensive literature search was performed in major databases including Medline, EMBASE, CINAHL, Cochrane Library, Web of Science, and BIOSIS from 2005 onwards. Thirty-eight studies were retrieved. Based on the synthesis of the reviewed literature, six themes emerged. Thirty-four articles covered more than one theme. From which, 24 articles were on modifying factors in FENO measurement, 18 on FENO in COPD compared with healthy subjects, and seven on FENO in ACO compared with COPD, 22 on FENO and disease severity/progression,12 on FENO and biomarkers, and eight on FENO and treatment response. FENO measurement cannot be used alone in the clinical settings of COPD patients. Although FENO level is higher in ACO patients than COPD-only, it is still unclear if there is a FENO cut-off that can be used to make the diagnosis of ACO and/or to guide therapy with inhaled corticosteroids/glucocorticoids in COPD patients.

Cigarette Smoke-Induced Acquired Dysfunction of Cystic Fibrosis Transmembrane Conductance Regulator in the Pathogenesis of Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a disease state characterized by airflow limitation that is not fully reversible. Cigarette smoke and oxidative stress are main etiological risks in COPD. Interestingly, recent studies suggest a considerable overlap between chronic bronchitis (CB) phenotypic COPD and cystic fibrosis (CF), a common fatal hereditary lung disease caused by genetic mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Phenotypically, CF and COPD are associated with an impaired mucociliary clearance and mucus hypersecretion, although they are two distinct entities of unrelated origin. Mechanistically, the cigarette smoke-increased oxidative stress-induced CFTR dysfunction is implicated in COPD. This underscores CFTR in understanding and improving therapies for COPD by altering CFTR function with antioxidant agents and CFTR modulators as a great promising strategy for COPD treatments. Indeed, treatments that restore CFTR function, including mucolytic therapy, antioxidant ROS scavenger, CFTR stimulator (roflumilast), and CFTR potentiator (ivacaftor), have been tested in COPD. This review article is aimed at summarizing the molecular, cellular, and clinical evidence of oxidative stress, particularly the cigarette smoke-increased oxidative stress-impaired CFTR function, as well as signaling pathways of CFTR involved in the pathogenesis of COPD, with a highlight on the therapeutic potential of targeting CFTR for COPD treatment.

Alveolar and Bronchial Nitric Oxide in Chronic Obstructive Pulmonary Disease and Asthma-COPD Overlap

INTRODUCTION

Exhaled nitric oxide (F_ENO) measurements differentiate COPD phenotypes from asthma-COPD overlap (ACO). To date, no study has been conducted to determine whether alveolar and bronchial components differ in this group of patients.

METHODS

This was an observational cross-sectional study recruiting ambulatory COPD patients. F_ENO was measured, differentiating alveolar (C_ANO) from bronchial (J_awNO) components using a multiple-flow technique. C_ANO and J_awNO values were compared between eosinophilic COPD patients (defined as ≥ 300 eosinophils/μL in peripheral blood test, or ≥ 2% eosinophils or ≥ 3% eosinophils), and a linear regression analysis was performed to determine clinical and biological variables related to these measurements.

RESULTS

73 COPD patients were included in the study. Eosinophil counts were associated with increased values of C_ANO and J_awNO (for the latter only the association with ≥ 300 or ≥ 3% eosinophils was significant). C_ANO was also associated with CRP, and J_awNO with smoking.

CONCLUSIONS

Patients with COPD and ACO characteristics show increased inflammation in the large and small airways. C_ANO and J_awNO are associated with clinical and biological variables.

Persistently elevated exhaled nitric oxide fraction is associated with increased risk of exacerbation in COPD

Preventing the occurrence of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) is a major therapeutic goal. We hypothesise that persistently increased levels of exhaled nitric oxide (F_eNO) during follow-up can identify a group of COPD patients at higher risk of AECOPD.To test this hypothesis, we measured F_eNO levels (HypAir F_eNO®, Medisoft; Sorinnes, Belgium) prospectively in 226 clinically stable COPD outpatients at recruitment and during follow-up (at 6 and 12 months). Patients were stratified according to the number of visits with F_eNO ≥20 ppb.F_eNO was <20 ppb in all three visits in 44.2% of patients, 29.6% in visit 1 and 26.1% in visit 2 or 3. These three groups suffered progressively higher AECOPD rates during follow-up (0.67, 0.91 and 1.42, respectively, p<0.001). After adjusting for potential confounding variables (log-rank test), the hazard ratio for AECOPD was higher in the latter group (1.579 (95% CI 1.049-2.378), p=0.029). Likewise, time to first moderate and severe AECOPD was shorter in these patients. Finally, there was no relationship between F_eNO levels and circulating eosinophils.Persistent F_eNO levels ≥20 ppb in clinically stable COPD outpatients are associated with a significantly higher risk of AECOPD.

Effect of the asthma-chronic obstructive pulmonary disease syndrome on the stroke, Parkinson's disease, and dementia: a national cohort study

Background

To evaluate the association of asthma–chronic obstructive pulmonary disease syndrome (ACOS) with neurodegenerative diseases (stroke, Parkinson's disease and dementia) and the role of the steroids in the neurodegenerative diseases among the ACOS cohort.

Materials and Methods

Comparison of the ACOS cohort (N = 10,260) with the non-ACOS cohort (n = 20,513) based on the patients aged ≧40 years in the National Health Insurance Research Database from January 1, 2000 to December 31, 2010. These patients follow up to diagnosis of neurodegenerative diseases or the December 31, 2011; using multivariable Cox proportional hazards models.

Results

After adjustment for potential confounders, the [adjusted hazard ratio (aHR), 95% confidence interval (CI)] in the ACOS cohort were [1.39, 1.28–1.50] [1.56, 1.34–1.81] and [1.43, 1.29–1.59] for stroke, Parkinson's disease, dementia; respectively. The [aHR, 95% CI] for ACOS cohort with (inhaler corticosteroids ≧0.13 gram/ oral steroids ≧0.08gram) were with less risk (all aHR<1, p values <0.05) for these 3 neurodegenerative diseases except Parkinson's disease with inhaler corticosteroids >0.43 gram. The risk of stroke and dementia were the lower in patients with < 250 μg/d of a fluticasone equivalent inhaler corticosteroids (aHR = 0.53, 95% CI = 0.35–0.79; aHR = 0.53, 95% CI = 0.31–0.90, respectively).

Conclusions

The ACOS cohort had a higher risk of the neurodegenerative diseases. The lower dose of the inhaler corticosteroids with cumulative dose ≧0.13 gram have the less risk of stroke and dementia.

Investigating fractional exhaled nitric oxide (FeNO) in chronic obstructive pulmonary disease (COPD) and asthma-COPD overlap (ACO): a scoping review protocol

INTRODUCTION

During the last decade, many articles have been published, including reviews on fractional exhaled nitric oxide (FeNO) use and utility in clinical practice and for monitoring and identifying eosinophilic airway inflammation, especially in asthma, and evaluating corticosteroid responsiveness. However, the exact role of FeNO in patients with chronic obstructive pulmonary disease (COPD) and its ability to distinguish patients with COPD and those having concomitant asthma, that is, asthma-COPD overlap (ACO) is still unclear and needs to be defined. Due to the broad topics of FeNO in chronic airway disease, we undertook a scoping review. The present article describes the protocol of a scoping review of peer-reviewed published literature specific to FeNO in COPD/ACO over the last decade.

METHODS AND ANALYSIS

We used Joanna Briggs Institute Reviewers' Manual scoping review methodology as well as Levac et al's and Arksey et al's framework as guides. We searched a variety of databases, including Medline, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library, Web of Science, and BioSciences Information Service (BIOSIS) on 29 June 2016. Additional studies will be recognised by exploring the reference list of identified eligible studies. Screening of eligible studies will be independently performed by two reviewers and any disagreement will be solved by the third reviewer. We will analyse the gathered data from article bibliographies and abstracts.

ETHICS AND DISSEMINATION

To investigate the body of published studies regarding the role of FeNO in patients with COPD and its usefulness in the clinical setting, a scoping review can be used as a modern and pioneer model, which does not need ethics approval. By this review, new insights for conducting new research specific to FeNO in COPD/ACO population will emerge. The results of this study will be reported in the scientific meetings and conferences, which aim to provide information to the clinicians, primary care providers and basic science researchers.

The relationship of depression in asthma-chronic obstructive pulmonary disease overlap syndrome

Purpose

To clarify the relationship between asthma–chronic obstructive pulmonary disease overlap syndrome (ACOS) and depression.

Methods

We identified 10,911 patients who received an ACOS diagnosis and concurrent treatment between January 2000 and December 2009. Subjects without ACOS were included in the non-ACOS cohort (n = 10,911). Cox proportional hazard regression analysis was performed to compare the risk of depression between the ACOS and non-ACOS cohorts.

Results

The risk of depression was higher in the ACOS cohort than in the non-ACOS cohort (adjusted hazard ratios (aHRs) = 1.67, 95% confidence interval [CI] = 1.48–1.88). In the ACOS cohort, the aHRs for depression were [2.44 (95% CI = 1.45–4.11); 2.36 (95% CI = 1.58–3.52)] in patients [aged 20–39 years; without comorbidity]. In the ACOS cohort, the aHRs for depression were 1.70 (95% CI = 1.51–1.93) and 1.84 (95% CI = 1.55–2.19) in patients without inhaled corticosteroids (ICSs) and oral steroids (OSs) use, respectively. Moreover, the aHRs for the risk of depression were 1.16 (95% CI = 0.95–1.41) and 1.12 (95% CI = 0.96–1.29) in patients with ICSs and OSs use, respectively.

Conclusion

The risk of depression is higher in ACOS patients, even in those without comorbidities or in young adults. The events of the depression were not significant difference in patients receiving the ICSs/OSs between the ACOS and the non-ACOS cohorts.

Association of asthma-chronic obstructive pulmonary disease overlap syndrome with coronary artery disease, cardiac dysrhythmia and heart failure: a population-based retrospective cohort study

OBJECTIVES

Patients with asthma-chronic obstructive pulmonary disease (COPD) overlap syndrome (ACOS) and cardiovascular diseases (CVDs) share common risk factors. However, the association between ACOS and the incidence of CVDs has not been reported. This study investigated the relationship between CVDs and ACOS in the general population.

SETTING

Data were obtained from Taiwan's National Health Insurance Research Database for the period 2000 to 2010.

PARTICIPANTS

The ACOS cohort comprised patients (n=5814) who had received a diagnosis of asthma and COPD. The non-ACOS cohort comprised patients who had not received a diagnosis of asthma or COPD and were matched to the ACOS cohort (2:1) by age, sex and index date (n=11 625).

PRIMARY AND SECONDARY OUTCOME MEASURES

The cumulative incidence of CVDs-coronary artery disease (CAD), cardiac dysrhythmia (CD) and heart failure (HF)-was calculated. Cox proportional regression analysis was employed to examine the relationship between ACOS and CVDs.

RESULTS

After adjustment for multiple confounding factors-age, sex, comorbidities and medications-patients with ACOS were associated with a significantly higher risk of CVDs; the adjusted HRs (aHRs; 95% CI) for CAD, CD and HF were 1.62 (1.50 to 1.76), 1.44 (1.30 to 1.61) and 1.94 (1.73 to 2.19), respectively, whereas those of beta-blockers treatment for CAD, CD and HF were 1.19 (0.92 to 1.53), 0.90 (0.56 to 1.45) and 0.82 (0.49 to 1.38). The aHR of atenolol treatment for CD was 1.72 (1.01 to 2.93). The aHRs (95% CIs) of ACOS without acute exacerbation of COPD (AE-COPD) for CAD, CD and HF were 1.85 (1.70 to 2.01), 1.57 (1.40 to 1.77) and 2.07 (1.82 to 2.35), respectively.

CONCLUSION

ACOS was associated with higher CVD risk, even without the presence of previous comorbidities or AE-COPD. No significant differences in CVD events were observed in the ACOS cohort using beta-blockers, except for those using atenolol for treating CD.