Associated demographics of persistent exhaled nitric oxide elevation in treated asthmatics

Blood eosinophil count variability in chronic obstructive pulmonary disease and severe asthma

BACKGROUND

Blood eosinophils are essential biomarkers that vary substantially over time in patients with COPD and asthma. However, no study has identified the changes and effects in the changes of the blood eosinophil counts over time in both diseases. This study aimed to demonstrate blood eosinophil variability in patients with COPD and severe asthma based on these backgrounds.

METHODS

A total of 172 patients with COPD from the Hokkaido COPD cohort study and 96 patients with severe asthma from the Hokkaido Severe Asthma Cohort Study, whose blood eosinophil counts were measured annually over a 3-year period, were analyzed. The factors contributing to consistently high or low blood eosinophil counts were examined in each cohort. The stability of the eosinophil classification (<150, 150-299, ≥300 cells/μL) was compared based on the number of asthma-like features in patients with COPD and the smoking status in patients with severe asthma.

RESULTS

Among all the patients, the most stable range of baseline blood eosinophil counts differed between the two diseases, with <150 cells/μL in COPD and ≥300 cells/μL in severe asthma. In COPD, the number of asthma-like features (bronchodilator reversibility, blood eosinophilia, and atopy) affects the blood eosinophil count variation patterns. In severe asthma, smoking status did not affect the blood eosinophil count variation patterns.

CONCLUSIONS

We identified variations in the blood eosinophil counts and their contributing factors in patients with COPD and severe asthma.

Differential role of mucus plugs in asthma: Effects of smoking and association with airway inflammation

BACKGROUND

The physiological importance of mucus plugs in computed tomography (CT) imaging is being increasingly recognized. However, whether airway inflammation and smoking affect the association between mucus plugs and clinical-physiological outcomes in asthma remains to be elucidated. The objective of this study is to examine how airway inflammation and/or smoking affect the correlation of CT-based mucus plug scores with exacerbation frequency and airflow limitation indices in asthma.

METHODS

A total of 168 patients with asthma who underwent chest CT and sputum evaluation were enrolled and classified in eosinophilic asthma (EA; n = 103) and non-eosinophilic asthma (NEA; n = 65) groups based on sputum eosinophil percentage (cut-off: 3%). The mucus plug score was defined as the number of lung segments with mucus plugs seen on CT.

RESULTS

More mucus plugs were detected on CT scans in the EA group than in the NEA group, regardless of smoking status. Mucus plug score and exacerbation frequency during one year after enrollment were significantly associated in the EA group but not in the NEA group after adjusting for demographics, blood eosinophil count, and fractional exhaled nitric oxide. Mucus plug score was associated with percentage of predicted forced expiratory volume in 1 s in non-smoking individuals in the EA and NEA group and in smoking individuals in the EA group but not in the NEA group after adjusting for demographics.

CONCLUSIONS

The association of mucus plug score with exacerbation frequency and reduced lung function may vary due to airway inflammatory profile and smoking status in asthma.

Blood eosinophil counts in the general population and airways disease: a comprehensive review and meta-analysis

BACKGROUND

The clinical context for using blood eosinophil (EOS) counts as treatment-response biomarkers in asthma and COPD requires better understanding of EOS distributions and ranges. We describe EOS distributions and ranges published in asthma, COPD, control (non-asthma/COPD) and general populations.

METHODS

We conducted a comprehensive literature review and meta-analysis of observational studies (January 2008 to November 2018) that included EOS counts in asthma, severe asthma, COPD, control and general populations. Excluded studies had total sample sizes <200, EOS as inclusion criterion, hospitalised population only and exclusively paediatric participants.

RESULTS

Overall, 91 eligible studies were identified, most had total-population-level data available: asthma (39 studies), severe asthma (12 studies), COPD (23 studies), control (seven studies) and general populations (14 studies); some articles reported data for multiple populations. Reported EOS distributions were right-skewed (seven studies). Reported median EOS counts ranged from 157-280 cells·µL-1 (asthma, 22 studies); 200-400 cells·µL-1 (severe asthma, eight studies); 150-183 cells·µL-1 (COPD, six studies); and 100-160 cells·µL-1 (controls, three studies); and 100-200 cells·µL-1 (general populations, six studies). The meta-analysis showed that observed variability was mostly between studies rather than within studies. Factors reportedly associated with higher blood EOS counts included current smoking, positive skin-prick test, elevated total IgE, comorbid allergic rhinitis, age ≤18 years, male sex, spirometric asthma/COPD diagnosis, metabolic syndrome and adiposity.

CONCLUSION

EOS distribution and range varied by study population, and were affected by clinical factors including age, smoking history and comorbidities, which, regardless of severity, should be considered during treatment decision-making.

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.

Evaluation of olfactory dysfunction to estimate the presence of eosinophilic chronic rhinosinusitis in patients with asthma

BACKGROUND

Eosinophilic chronic rhinosinusitis (ECRS) is often complicated by asthma and can be difficult to diagnose. This study aimed to clarify the usefulness of the self-administered odor questionnaire (SAOQ) and visual analog scale (VAS) to identify olfactory disorders in patients with asthma.

METHODS

This retrospective study was conducted on patients with asthma who were referred to the Otolaryngology clinic between May and September 2018. The treatment step of asthma, asthma control test (ACT), pulmonary function test, peripheral blood eosinophils, and fractional exhaled nitric oxide (FeNO) were analyzed. ECRS was diagnosed based on the Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis Study score. Olfactory dysfunction was evaluated using the SAOQ and VAS for olfactory disorders.

RESULTS

The study included 56 patients (18 males and 38 females), who were divided into two groups; those with ECRS (n = 18) and those without ECRS (n = 38). Age, sex, treatment step, ACT score, and pulmonary function were not significantly different between the groups. The ECRS group had a significantly higher FeNO value (89.1 ppb vs. 39.1 ppb) and a significantly lower SAOQ score (40.1% vs. 96.1%). The area under the receiver operating characteristic curve for the efficacy of ECRS diagnosis was 0.88, 0.889, 0.799, and 0.757 for SAOQ, VAS, blood eosinophil count, and FeNO, respectively.

CONCLUSION

The SAOQ and VAS scores were useful tools that presented similar results to the blood eosinophil count and FeNO, and may help to improve the diagnosis of ECRS in patients with asthma.

An official JRS statement: The principles of fractional exhaled nitric oxide (FeNO) measurement and interpretation of the results in clinical practice

Nitric oxide (NO) is produced in the body and has been shown to have diverse actions in the abundance of research that has been performed on it since the 1970s, leading to Furchgott, Murad, and Ignarro receiving the Nobel Prize in Physiology or Medicine in 1998. NO is produced by nitric oxide synthase (NOS). NOS is broadly distributed, being found in the nerves, blood vessels, airway epithelium, and inflammatory cells. In asthma, inflammatory cytokines induce NOS activity in the airway epithelium and inflammatory cells, producing large amounts of NO. Measurement of fractional exhaled nitric oxide (FeNO) is a simple, safe, and quantitative method of assessing airway inflammation. The FeNO measurement method has been standardized and, in recent years, this noninvasive test has been broadly used to support the diagnosis of asthma, monitor airway inflammation, and detect asthma overlap in chronic obstructive pulmonary disease (COPD) patients. Since the normal upper limit of FeNO for healthy Japanese adults is 37 ppb, values of 35 ppb or more are likely to be interpreted as a signature of inflammatory condition presenting features with asthma, and this value is used in clinical practice. Research is also underway for clinical application of these measurements in other respiratory diseases such as COPD and interstitial lung disease. Currently, there remains some confusion regarding the significance of these measurements and the interpretation of the results. This statement is designed to provide a simple explanation including the principles of FeNO measurements, the measurement methods, and the interpretation of the measurement results.

Impact of sinus surgery on type 2 airway and systemic inflammation in asthma

Objective: Asthma is frequently associated with chronic rhinosinusitis with nasal polyps (CRSwNP). Although endoscopic sinus surgery (ESS) improves asthma control in CRSwNP patients with asthma, the mechanism that underlies the response to surgical treatment is still unclear. We evaluated the relevance of changes in asthma control and changes in airway/systemic inflammation in eosinophilic CRSwNP patients with not well controlled asthma who underwent ESS.Methods: We prospectively assessed changes in the asthma control questionnaire (ACQ) score, blood eosinophil counts (B-Eos), forced expiratory volume in 1 s (FEV₁), and fraction of exhaled nitric oxide (FeNO) levels at 1-week before and 8 and 52 weeks after ESS.Results: Twenty-five subjects were analyzed. The ACQ score, B-Eos, and FeNO decreased, and FEV₁ increased significantly after ESS. In the period from baseline to 52 weeks after ESS, changes in ACQ were significantly correlated with the changes in blood eosinophil counts (r = 0.58, p<.01) and FeNO (r = 0.45, p<.05). Ten subjects (40%) showed consistently improved asthma control at 52-weeks after ESS. In the remaining subjects, although the ACQ score temporarily improved at 8-weeks after ESS, but eventually deteriorated at 52-weeks. Higher levels of total immunoglobulin E were associated with long-term improved asthma control after ESS.Conclusions: In eosinophilic CRSwNP patients with asthma, sinus surgery impacts asthma control through the suppression of airway/systemic type 2 inflammation. The present study reinforced the common pathophysiology of type 2 inflammation between the upper and lower airways.

Factors Associated with Physician-Patient Discordance in the Perception of Asthma Control

BACKGROUND

Physicians' perception of asthma control has a direct impact on treatment options and patients' outcomes.

OBJECTIVE

To analyze the differences between patients and their physicians in the perception of asthma control. Moreover, factors associated with this discordance were explored.

METHODS

A multicenter, cross-sectional survey was conducted in patients visiting primary or secondary facilities for routine asthma reviews. Before the review, patients completed the 5-iteam Asthma Control Questionnaire (ACQ) under the supervision of a medical staff. Physicians recorded their perception of the patients' asthma control without viewing the ACQ results. After the review, physicians completed the demographic and clinical data.

RESULTS

A total of 1697 patients were included. ACQ results showed that asthma was well controlled in 52.2% of the patients, but physicians perceived that 79.6% of patients were well controlled. The concordance analyzed by the kappa index was weak (0.27). The discordant physician-patient pairs had significantly worse ACQ scores than the concordant pairs (P < .0001), but the use of neither inhaled corticosteroids nor other controller medications showed any differences between the groups. In a multivariate model, ACQ score of 0.75 or more and lack of lung function assessment within the previous 6 months were independently associated with the physician-patient discordance in the perception of asthma control.

CONCLUSIONS

The subjective perception of the physicians did not show a good agreement with the patients' asthma control based on validated ACQ scores, with increased rates of discordance among patients whose asthma was not well controlled and patients who had not received lung function assessment.

Distinct Phenotypes of Smokers with Fixed Airflow Limitation Identified by Cluster Analysis of Severe Asthma

RATIONALE

Smoking may have multifactorial effects on asthma phenotypes, particularly in severe asthma. Cluster analysis has been applied to explore novel phenotypes, which are not based on any a priori hypotheses.

OBJECTIVES

To explore novel severe asthma phenotypes by cluster analysis when including smoking patients with asthma.

METHODS

We recruited a total of 127 subjects with severe asthma, including 59 current or ex-smokers, from our university hospital and its 29 affiliated hospitals/pulmonary clinics. Clinical variables obtained during a 2-day hospital stay were used for cluster analysis. After clustering using clinical variables, the sputum levels of 14 molecules were measured to biologically characterize the clinical clusters.

RESULTS

Five clinical clusters, including two characterized by low forced expiratory volume in 1 second/forced vital capacity, were identified. When characteristics of smoking subjects in these two clusters were compared, there were marked differences between the two groups: one had high levels of circulating eosinophils, high immunoglobulin E levels, and a high sinus score, and the other was characterized by low levels of the same parameters. Sputum analysis revealed intriguing differences of cytokine/chemokine pattern in these two groups. The other three clusters were similar to those previously reported: young onset/atopic, nonsmoker/less eosinophilic, and female/obese. Key clinical variables were confirmed to be stable and consistent 3 years later.

CONCLUSIONS

This study reveals two distinct phenotypes with potentially different biological pathways contributing to fixed airflow limitation in cigarette smokers with severe asthma.

Sensitization to Staphylococcus aureus enterotoxins in smokers with asthma

BACKGROUND

Sensitization to Staphylococcus aureus enterotoxins (SEs) augments eosinophilic inflammation in asthma. Recent epidemiologic studies demonstrate that sensitization to SEs is increased in healthy smokers; however, there is no evidence on the association between sensitization to SEs and eosinophilic inflammation in smokers with asthma.

OBJECTIVE

To clarify the role of SEs on clinical indexes, including eosinophilic inflammation and lung function in smokers with asthma.

METHODS

The frequency of atopic sensitization to SEs was examined in adult patients with asthma. In current or ex-smokers with asthma, the association of sensitization to SEs with eosinophilic inflammation, airflow limitation, or treatment steps was determined. Clinical indexes were examined at the first visit, and treatment steps were assessed 6 months after enrollment.

RESULTS

Overall, 23 current smokers, 40 ex-smokers, and 118 never smokers with asthma were enrolled. The frequency of sensitization to SEs, but not to other aeroallergens, was significantly higher in current, ex-, and never smokers, in decreasing order. In current or ex-smokers with asthma, patients with sensitization to SEs exhibited higher serum levels of total and specific IgE to aeroallergens, higher blood eosinophil counts, greater airflow limitation, and more severe disease 6 months later than those without sensitization to SE. A longer smoking abstinence period was associated with serum specific IgE levels to SEs, and 3 years was the best cutoff of abstinence period to predict the absence of sensitization to SEs.

CONCLUSION

Sensitization to SEs is increased in smokers with asthma, and it may be a marker of eosinophilic inflammation and severe asthma in smokers with asthma.

TRIAL REGISTRATION

umin.ac.jp Identifier: UMIN000007818.

Utility of serum periostin in combination with exhaled nitric oxide in the management of asthma

Type-2/eosinophilic inflammation plays a pivotal role in asthma. The identification of severe type-2/eosinophilic asthma is important for improving the management of patients with asthma. Therefore, efforts to develop non-invasive biomarkers for type-2/eosinophilic airway inflammation have been made during this decade. Currently, fraction of exhaled nitric oxide (FeNO) and serum periostin levels are considered markers of type-2/eosinophilic inflammation in asthma. However, a single-marker approach has limited the ability to diagnose severe type-2/eosinophilic asthma accurately and predict disease outcomes precisely. The present article reviews the utility of FeNO and serum periostin levels in a single-marker approach and in a multiple-marker approach in identifying patients with severe type-2/eosinophilic asthma. Furthermore, based on a sub-analysis of the Kinki Hokuriku Airway disease Conference (KiHAC), geno-endo-phenotypes of patients were stratified into four groups according to the FeNO and serum periostin levels.

A trial of oral corticosteroids for persistent systemic and airway inflammation in severe asthma

Introduction

The fraction of exhaled nitric oxide (FeNO) and blood eosinophils, markers of local and systemic eosinophilic inflammation, respectively, are increased in asthmatic patients. Little is known concerning the relationship between the FeNO levels and blood eosinophils in asthmatics.

Methods

Twenty severe asthmatics with persistent FeNO elevation (≥40 ppb) and blood eosinophilia (≥3%) despite maintenance therapy including high‐daily‐dose inhaled corticosteroids were analyzed. We investigated the response of FeNO and blood eosinophils to systemic corticosteroids treatment and the change in Asthma Control Questionnaire (ACQ) according to differences in the response of FeNO and blood eosinophils to steroid.

Results

The changes in blood eosinophils were not correlated with the changes in FeNO levels by systemic steroid treatment (r = 0.37, P = 0.11). 50% of the subjects showed both ≥20% reductions in FeNO levels and blood eosinophils. There were significant differences in the ACQ score between the steroid response group and poor response group (P < 0.005). The group in which both FeNO and blood eosinophils were suppressed fulfilled the change in score of ≥0.5 on the ACQ.

Conclusions

In the patients with severe asthma, responses to systemic corticosteroids were variable in terms of FeNO and blood eosinophils. It was necessary to suppress both persistent eosinophilia and high FeNO for the improvement of asthma control.

Determinants of Incomplete Asthma Control in Patients with Allergic Rhinitis and Asthma

BACKGROUND

Characterizing associations between the upper and lower airways is important for asthma management.

OBJECTIVES

This study aimed to assess the determinants of incomplete asthma control in patients with allergic rhinitis (AR) and asthma.

METHODS

Multiple factors including age, sex, atopy, smoking history, medication use, Asthma Control Questionnaire (ACQ) score, FEV₁, fraction of exhaled nitric oxide (Feno), and rhinitis questionnaire score were examined. AR was defined by rhinitis symptoms and the sensitization to inhaled allergens. ACQ was used to dichotomize the subjects into the incompletely controlled group (ACQ score ≥0.75) and the well-controlled group. The factors that contribute to incomplete asthma control were assessed by a multivariate analysis.

RESULTS

A total of 260 patients with AR and asthma were enrolled and 108 patients (42%) were classified as incomplete asthma control. The incompletely controlled group was older (P < .05), and had more airflow limitation, more airway inflammation, and more severe rhinitis symptoms (all P < .001). In contrast, the well-controlled group was more likely to be taking nasal corticosteroids (NCSs) (P < .01). In a multivariate model adjusted by age, asthma treatment, airflow limitation, and Feno, persistence and severity of rhinitis (odds ratio [OR], 2.57; 95% CI, 1.41-4.70, and OR, 2.00; 95% CI, 1.10-3.65) and nonuse of NCSs (OR, 3.83; 95% CI, 1.50-9.81) were independently associated with incomplete asthma control.

CONCLUSIONS

The persistence and severity of AR and the use of NCSs were associated with the level of asthma control in patients with AR and asthma. Further studies are required to determine whether appropriate treatment of rhinitis would improve asthma control.

Distinct Phenotypes of Cigarette Smokers Identified by Cluster Analysis of Patients with Severe Asthma

RATIONALE

Smoking may have multifactorial effects on asthma phenotypes, particularly in severe asthma. Cluster analysis has been applied to explore novel phenotypes, which are not based on any a priori hypotheses.

OBJECTIVES

To explore novel severe asthma phenotypes by cluster analysis when including cigarette smokers.

METHODS

We recruited a total of 127 subjects with severe asthma, including 59 current or ex-smokers, from our university hospital and its 29 affiliated hospitals/pulmonary clinics. Twelve clinical variables obtained during a 2-day hospital stay were used for cluster analysis. After clustering using clinical variables, the sputum levels of 14 molecules were measured to biologically characterize the clinical clusters.

MEASUREMENTS AND MAIN RESULTS

Five clinical clusters were identified, including two characterized by high pack-year exposure to cigarette smoking and low FEV1/FVC. There were marked differences between the two clusters of cigarette smokers. One had high levels of circulating eosinophils, high IgE levels, and a high sinus disease score. The other was characterized by low levels of the same parameters. Sputum analysis revealed increased levels of IL-5 in the former cluster and increased levels of IL-6 and osteopontin in the latter. The other three clusters were similar to those previously reported: young onset/atopic, nonsmoker/less eosinophilic, and female/obese. Key clinical variables were confirmed to be stable and consistent 1 year later.

CONCLUSIONS

This study reveals two distinct phenotypes of severe asthma in current and former cigarette smokers with potentially different biological pathways contributing to fixed airflow limitation. Clinical trial registered with www.umin.ac.jp (000003254).

Persistently high exhaled nitric oxide and loss of lung function in controlled asthma

BACKGROUNDS

It remains unclear whether a persistently high exhaled nitric oxide fraction (FeNO) in patients with controlled asthma is associated with the progressive loss of lung function.

METHODS

This was a 3-year prospective study. We examined the changes in pre- and post-bronchodilator forced expiratory volume in 1 s (FEV1) and FeNO in 140 patients with controlled asthma. We initially determined the FeNO cut-off point for identifying patients with a rapid decline in FEV1 (>40 mL/yr). Next, a total of 122 patients who maintained high or non-high FeNO were selected, and the associations between the FeNO trend and changes in FEV1 and bronchodilator response (BDR) were investigated.

RESULTS

A FeNO level >40.3 ppb yielded 43% sensitivity and 86% specificity for identifying patients with a rapid decline in FEV1. Patients with persistently high FeNO had higher rates of decline in FEV1 (42.7 ± 37.5 mL/yr) than patients with non-high FeNO (16.7 ± 31.5 mL/yr) (p < 0.0005). The changes in BDR from baseline to the end of the study, in patients who had high or non-high levels of FeNO were -0.8% and 0.1%, respectively (p < 0.01). In a multivariate analysis adjusted by age, body mass index, asthma control, blood eosinophil numbers, and FEV1% of predicted, a FeNO level of ≥40 ppb was independently associated with an accelerated decline in FEV1 (p < 0.05).

CONCLUSIONS

This study suggests that FeNO is potentially valuable tool for identifying individuals who are at risk of a progressive loss of lung function among patients with controlled asthma.

Prevalence of sinusitis and efficacy of intranasal corticosteroid treatment on asthmatic symptoms in asthmatic patients with rhinosinusitis: a pilot study

BACKGROUND

Prevalence of sinusitis on sinus computed tomography (CT) in asthmatic patients and efficacy of intranasal corticosteroid treatment on asthmatic symptoms in asthmatic patients with rhinosinusitis on sinus CT is unclear.

METHODS

Sinus CT of asthmatic patients were evaluated using the Lund-Mackay system (LMS). Intranasal corticosteroid treatment (mometasone furoate) was newly added to symptomatic asthmatic patients with rhinosinusitis treated without intranasal corticosteroids, and the findings of the Asthma Control Test (ACT), Asthma Control Questionnaire in 5 items (ACQ5), spirometry, and sinus CT were evaluated before and 3 months after additional intranasal corticosteroid treatment.

RESULTS

In a total of 160 asthmatic patients, rhinosinusitis and maxillary, ethmoidal, sphenoidal, and frontal sinusitis were observed in 75.0%, 70.0%, 53.1%, 33.1%, and 28.8%, respectively. Nasal symptoms and rhinophonia were observed in 81.9% and 72.5%, respectively, and patients with nasal symptoms and those with rhinophonia both showed significantly higher LMS scores in each sinus. Chronic rhinosinusitis (CRS) was observed in 66.9%, and these patients had significantly more severe asthma than the patients without CRS. In patients with CRS, patients with rhinophonia showed significantly higher LMS scores than those without rhinophonia. ACT, ACQ5, and the value of the forced expiratory volume in 1 second (FEV1) all significantly improved 3 months after the additive intranasal corticosteroid treatment in 24 patients, despite the fact that their LMS scores remained unchanged.

CONCLUSION

Additive intranasal corticosteroid treatment may be an effective treatment option for symptomatic asthmatic patients with rhinosinusitis.

Residual exhaled nitric oxide elevation in asthmatics is associated with eosinophilic chronic rhinosinusitis

OBJECTIVE

Eosinophilic chronic rhinosinusitis (ECRS) is as a subgroup of chronic rhinosinusitis (CRS) with nasal polyps. ECRS is a refractory disease closely related to bronchial asthma. Fractionated exhaled nitric oxide (FeNO) levels were reportedly elevated in some asthmatics with CRS after adequate treatment, suggesting that residual eosinophilic airway inflammation or ECRS might affect FeNO levels.

METHODS

To investigate the association between asthma with ECRS and FeNO levels, we examined FeNO levels in 133 asthmatics (99 with ECRS and 34 without ECRS) and 13 patients with ECRS without asthma. The severity of asthma was defined by the Global Initiative for Asthma guidelines and that of sinusitis was evaluated by the sinus CT score based on the Lund-Mackay scale.

RESULTS AND CONCLUSIONS

FeNO levels were elevated even in well-controlled asthmatics with ECRS, whereas asthmatics without ECRS and ECRS patients without asthma did not have high FeNO levels (>50 ppb). Although FeNO levels were not correlated with asthma severity, they were positively correlated with the sinus CT score. In asthmatics with ECRS, patients with higher FeNO levels had more severe ECRS and asthma. There is a possibility of having comorbid ECRS, particularly in asthmatics with high FeNO levels even after adequate treatment, including ICS, suggesting that asthma and ECRS may be closely associated as one airway disease with eosinophilic inflammation. Continual awareness of the coexistent ECRS is ideally recommended for asthmatics with high FeNO levels.

Progression of Irreversible Airflow Limitation in Asthma: Correlation with Severe Exacerbations

BACKGROUND

Severe exacerbations of asthma are periods of excess functional and pathological changes in the airways that have been proposed to induce airway remodeling.

OBJECTIVE

The objective of this study was to explore whether severe exacerbations are correlated with the decline in post-bronchodilator forced expiratory volume in 1 second (FEV1) and loss of bronchodilator reversibility (BDR).

METHODS

We examined the changes in FEV1 and BDR in 140 nonsmoking patients with well-controlled asthma at baseline and correlated these changes with the frequency of severe asthma exacerbations.

RESULTS

A 3-year follow-up assessment was completed in 128 patients. A total of 28 (21.9%) patients experienced at least 1 severe exacerbation with a mean rate of 0.16 year(-1). The exacerbation rate was significantly correlated with an annual rate of decline in FEV1 (ρ = 0.49, P < .0001). Both patients with 1 exacerbation and those with 2 or more exacerbations had greater declines in FEV1 than patients with no exacerbations (no exacerbation, 13.6 mL/year; 1 exacerbation, 41.3 mL/year; 2 or more exacerbations, 58.3 mL/year; P < .01 and P < .0001, respectively). The changes in BDR from baseline to the end of the study in patients who did or did not experience an exacerbation were -1.2% and 0.1%, respectively (P < .0005). The changes in BDR were significantly correlated with the annual rates of change in FEV1 (r = 0.40, P < .0001).

CONCLUSION

The occurrence of severe exacerbations of asthma is correlated with the progression of irreversible airflow limitation over time. This suggests that asthma exacerbations could have the long-term adverse consequences of structural and functional changes in the airways.

Characteristics of eosinophilic and non-eosinophilic asthma during treatment with inhaled corticosteroids

OBJECTIVE

Eosinophilic inflammation in the respiratory tract is a hallmark of bronchial asthma. In naïve cases, the inflammatory profile is associated with disease severity and reactivity to inhaled corticosteroids (ICS). Sustained airway eosinophilia has been reported during ICS treatment. However, the immunological characteristics of these cases are not known and it is unclear if this situation contributes to asthma control. This study was performed to determine the answer of these questions.

METHODS

To compare phenotypes of eosinophilic and non-eosinophilic asthma (EA and NEA, respectively) under ICS treatment, clinical data were obtained from asthmatic subjects (n = 22) and healthy controls (n = 10), and the leukocyte compositions of induced sputum and peripheral blood were determined. T lymphocyte profiles in systemic blood were assessed by flow cytometry.

RESULTS

A higher frequency of emergency room visits was observed in the NEA group, which had a higher neutrophil count relative to the total inflammatory cell population in induced sputum than the EA group (59.5 versus 36.6%; p < 0.01). The fraction of helper T (Th)17 lymphocytes as well as the ratio of Th17 to regulatory T cells (Treg) in the peripheral blood was higher in the NEA than in the EA group (0.24 versus 0.13; p < 0.05).

CONCLUSIONS

Th17 were more prevalent than Treg cells in the peripheral blood of NEA patients under ICS treatment, corresponding to neutrophil-dominant airway inflammation and a severe asthmatic phenotype. Thus, an imbalance in Th17/Treg may be associated with the pathogenesis of NEA in patients undergoing ICS treatment.

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.

Developments in the field of allergy in 2012 through the eyes of Clinical & Experimental Allergy

In 2012, we received 683 submissions and published 20 editorials, 38 reviews, 11 letters and 128 original articles. This represents an acceptance rate for original papers in the range of 20%. About 30% of original papers were triaged not to go out to review, either because the editors did not feel they had sufficient priority for publication or because the topic did not feel right for the readers of the journal. We place great emphasis on obtaining sufficient high-quality reviews to make our decisions on publication fair and consistent. Inevitably, however, there is a degree of luck about what gets published and which papers miss out, and we are always happy to receive an appeal on our decisions either at the triage stage or after review. This gives us the opportunity to revisit the decision and revise it or explain in more detail to the authors the basis for the decision. Once again in 2012, we were delighted by the quality of the papers submitted and the breadth and depth of research into allergic disease that it revealed. The pattern of papers submitted was similar in previous years with considerable emphasis on all aspects of asthma and rhinitis. We were particularly pleased with our special issue on severe asthma. Elucidating mechanisms using either animal models or patients has always been a major theme of the journal, and the excellent work in these areas has been summarized by Harissios Vliagoftis with a particularly interesting section on early-life events guiding the development of allergic disease, which understandably continue to be a major theme of research. Magnus Wickman summarized the papers looking at the epidemiology of allergic disease including work from birth cohorts, which are an increasingly rich source of data on risk factors for allergic disease, and two papers on the epidemiology of anaphylaxis. Giovanni Passalacqua discussed the papers in the clinical allergy section of the journal, and Adriano Mari who runs the excellent Allergome website discussed the papers looking at allergens including characterization and the relative usefulness of allergen arrays versus single extracts in diagnosis and management.

Changes in forced expiratory volume in 1 second over time in patients with controlled asthma at baseline

BACKGROUND

A predominant feature of asthma is an accelerated rate of decline in forced expiratory volume in 1 s (FEV1), but data on the variability and factors associated with this change in patients with controlled asthma are largely unknown.

METHODS

140 patients with controlled asthma were enrolled based on the Global Initiative for Asthma guidelines. We examined the data of a prospective analysis of the association between asthma control and change in FEV1 over time.

RESULTS

A 3-year follow-up assessment was completed in 128 patients. The mean rate of change in FEV1 was a decline of 22.2 mL yr(-1), with significant variation in the levels of change. The between patient standard deviation for the rate of decline was 34.1 mL yr(-1). We next classified the subjects of less than the 25th percentile as rapid decliners, and greater than the 25th percentile as non-rapid decliners. The decrease in the Asthma Control Test score over a 3-year period was higher for rapid decliners than that for non-rapid decliners (p < 0.001). The rapid decliner was more likely to be older, to have higher levels of FeNO, and to have had severe exacerbations during the study. Patients with severe exacerbations had a greater annual decline in FEV1 compared to patients with no exacerbations (-13.6 vs. -53.2 mL yr(-1), p < 0.0001).

CONCLUSIONS

Among patients with controlled asthma at baseline, the rate of change in FEV1 is highly variable. Severe exacerbations are strongly associated with a rapid loss of lung function.

Ongoing allergic rhinitis impairs asthma control by enhancing the lower airway inflammation

BACKGROUND

The relationship between allergic rhinitis and asthma is well accepted; however, little is known about the mechanism that underlies the interactions between the upper and lower airways.

OBJECTIVE

To investigate the symptomatic and inflammatory linkages between allergic rhinitis and asthma in patients with atopy.

METHODS

We enrolled 520 patients with asthma who were taking inhaled corticosteroids, and examined them by using the Asthma Control Questionnaire, spirometry, exhaled nitric oxide fraction (FENO), visual analog scale for nasal symptoms, allergic rhinitis questionnaire, and serum specific IgE (study 1). The symptomatic and inflammatory marker responses to nasal corticosteroids in patients with incompletely controlled asthma (Asthma Control Questionnaire > 0.75) and moderate-to-severe persistent allergic rhinitis were also observed (study 2).

RESULTS

A total of 348 patients (66.9%) had atopy and allergic rhinitis. There was a striking difference in the proportion of patients with incomplete asthma control, depending on the presence as well as the activity of rhinitis (no rhinitis, 11.0%; mild intermittent, 20.4%; moderate-to-severe intermittent, 44.6%; mild persistent, 53.1%; moderate-to-severe persistent, 65.7%). The FENO levels were increased with the activity of rhinitis, and the nasal visual analog scale was positively correlated with the FENO levels (r = 0.31; P < .0001). The additive treatment with nasal corticosteroids improved the nasal visual analog scale, Asthma Control Questionnaire, and FENO levels, and the changes in these variables were correlated with each other in all parameters (all P < .001).

CONCLUSION

This observational study of patients with atopy indicates that the ongoing allergic rhinitis is related to worsening of asthma by enhancing the lower airway inflammation.

Stratifying a risk for an increased variation of airway caliber among the clinically stable asthma

BACKGROUND

Recently, correlations of peak expiratory flow (PEF) variation have been shown to facilitate the prediction of later asthma symptoms and exacerbations. However, it has not been fully examined whether or not any patient characteristics are associated with the residual airway lability in treated asthmatics. The objective of this study is to examine a predictive marker for increased variation of PEF in patients with clinically stable asthma.

METHODS

We studied 297 asthmatic patients who were monitored for PEF twice a day. Asthma Control Questionnaire (ACQ), spirometry, and exhaled nitric oxide fraction (FENO) were measured. After the assessment of baseline values, PEF measuring was continued and associations between these clinical markers and later variation of PEF over a week (Min%Max) were investigated.

RESULTS

17.5% of the subjects showed increased PEF variability (Min%Max < 80%). ACQ, forced expiratory volume in 1 s % of predicted (%FEV1), and FENO were identified as independent predictors of Min%Max < 80%. An ACQ ≥ 0.4 yielded 96% sensitivity and 59% specificity, a %FEV1 ≤ 85% yielded 62% sensitivity and 89% specificity, and a FENO ≥ 40 ppb yielded 75% sensitivity and 90% specificity for identifying the subjects with high variability in PEF. When we combine %FEV1 ≤ 85% and FENO ≥ 40 ppb, this index showed the highest specificity (98%) for increased PEF variability.

CONCLUSIONS

These results indicate that ACQ, %FEV1 and FENO can stratify the risk for increased variation in airway caliber among patients with stable asthma. This may help identify subjects in whom further monitoring of lung function fluctuations is indicated.

Predictors for identifying the efficacy of systemic steroids on sustained exhaled nitric oxide elevation in severe asthma

BACKGROUND

Some patients with asthma have high levels of exhaled nitric oxide fraction (FENO) despite inhaled corticosteroids (ICS) therapy. Early studies suggested that this might be explained by the presence of heterogeneous airway inflammation. We aimed to assess the predictors for identifying the efficacy of systemic corticosteroids on residual FENO elevations in severe asthma.

METHODS

Twenty severe asthmatics with persistent FENO elevation (≥40ppb) despite maintenance therapy including high-daily-dose ICS were enrolled. Asthma Control Questionnaire (ACQ), lung function, blood eosinophils, and FENO were assessed before and after 14 days treatment with 0.5mg/kg oral prednisolone/day.

RESULTS

ACQ, blood eosinophils, FENO level, FVC, FEV1, FEV1/FVC ratio and the slope of the single nitrogen washout curve (ΔN2) were significantly improved by treatment with prednisolone. 70% of the subjects showed ≥20% reductions in the FENO levels. The reduction in FENO levels was significantly correlated with the improvements in ACQ (p < 0.0001), FVC (p < 0.01), FEV1 (p < 0.0001), and ΔN2 (p < 0.05). Among the measurements at baseline, the FENO levels and blood eosinophil numbers were identified as significant predictors of ≥20% reductions in the FENO levels by systemic steroid therapy.

CONCLUSIONS

Systemic corticosteroids could suppress the residual FENO elevations in more than half of the patients with severe asthma and the reduction in FENO levels was associated with improvements in asthma control and airflow limitation. The FENO levels and blood eosinophil numbers were the predictors of improved residual airway inflammation by systemic steroid therapy in severe asthma.

Influences of smoking and aging on allergic airway inflammation in asthma

Asthma is a heterogeneous disease with varying phenotypes and numerous risk factors. This condition results from complex interactions between genetic and environmental factors, and active smoking is one of these risk factors. The effects of aging should also be taken into account in these interactions. From an epidemiological standpoint, smokers and/or elderly patients with asthma are not small part in the total population with asthma. Furthermore, both smoking and aging are important risk factors for severe asthma. This review discusses the potential effects of smoking and aging on healthy subjects and patients with asthma, particularly from the perspective of inflammatory changes. First we show evidence that smokers and the elderly have increased neutrophil counts in their airways, which may have impacts on their clinical characteristics of elderly smokers with asthma. Secondly, on the basis of our recent findings on the interactions between smoking and aging in patients with asthma, we propose that IgE/eosinophilic inflammation should not be underestimated in elderly smokers with asthma, particularly those who are atopic. This review may expand our understanding of the effects of smoking and aging on asthma with a new perspective of an old issue.

Persistent elevation of exhaled nitric oxide and modification of corticosteroid therapy in asthma

BACKGROUND

Persistent airway inflammation, detected by fractional exhaled nitric oxide (FENO), is occasionally observed in asthmatic patients, even in those treated with inhaled corticosteroids (ICS). However, improvement in residual airway inflammation and pulmonary function through modification of corticosteroid therapy has not been proven.

METHODS

Thirteen asthmatic patients whose FENO levels were over 40 parts per billion (ppb), despite dry-powder ICS therapy, were enrolled. A 3-step change in steroid treatment was undertaken until FENO was less than 40ppb. In the first step, the powder formula was changed to an ultra-fine particle compound as an equipotent ICS dose. In the second step, the ICS dose was doubled. In the third step, oral corticosteroids were added. We measured pulmonary function and FENO and alveolar NO concentrations (CAlvNO).

RESULTS

Doubling the ICS dose and changing the ICS formula significantly improved FVC (p<0.001), FEV1 (p<0.05), the slope of the single nitrogen washout curve (dN2) (p<0.01), FENO (p<0.001), and CAlvNO (p<0.05), relative to baseline. The reductions in FENO were significantly associated with the improvement in airflow limitation assessed by dN2 (r=0.73, p=0.007). The remaining FENO elevation, even after doubling the ICS dose, did not decrease after oral corticosteroid administration.

CONCLUSIONS

These results suggest that modification of ICS therapy can suppress residual FENO elevation, and that reduction in FENO levels is associated with improvement in airflow limitation. However, steroid-resistance mechanisms may exist in some asthmatic patients with sustained FENO elevations.

Natural history and risk factors of obstructive changes over a 10-year period in severe asthma

BACKGROUND

The clinical features, physiology, and pathology of severe asthma are poorly understood. Recently, the forced vital capacity (FVC) has been shown to be reduced in severe asthma compared to mild asthma, possibly due to air trapping. However, the natural history and risk factors of obstructive change for such asthmatic patients have not been fully elucidated.

METHODS

We examined the data of a retrospective analysis of lung function changes over a 10-year period in 54 severe asthma patients.

RESULTS

The faster obstructive changes detected by FEV(1) (forced expiratory volume in one second) were accompanied by excessive loss of FVC (r = 0.85, p < 0.0001) and the reduction in FVC was 1.2 times larger than the FEV(1) change. Age, baseline FVC, exacerbation rate and oral corticosteroids use showed significantly negative correlations with the rate of annual change in FVC.

CONCLUSIONS

These data indicate that the decline in FVC is more evident than FEV(1) in severe asthma, suggesting that small airway susceptibility may be the cause of rapid disease progression. Aging, exacerbations of asthma, and use of systemic corticosteroids are related to excess FVC decline, particularly if FVC is still normal.

Storage conditions for stability of offline measurement of fractional exhaled nitric oxide after collection for epidemiologic research

Background

The measurement of fractional concentration of nitric oxide in exhaled air (FeNO) is valuable for the assessment of airway inflammation. Offline measurement of FeNO has been used in some epidemiologic studies. However, the time course of the changes in FeNO after collection has not been fully clarified. In this study, the effects of storage conditions on the stability of FeNO measurement in exhaled air after collection for epidemiologic research were examined.

Methods

Exhaled air samples were collected from 48 healthy adults (mean age 43.4 ± 12.1 years) in Mylar bags. FeNO levels in the bags were measured immediately after collection. The bags were then stored at 4°C or room temperature to measure FeNO levels repeatedly for up to 168 hours.

Results

In the bags stored at room temperature after collection, FeNO levels were stable for 9 hours, but increased starting at 24 hours. FeNO levels remained stable for a long time at 4°C, and they were 99.7% ± 7.7% and 101.3% ± 15.0% relative to the baseline values at 24 and 96 hours, respectively. When the samples were stored at 4°C, FeNO levels gradually decreased with time among the subjects with FeNO ≥ 51 ppb immediately after collection, although there were almost no changes among the other subjects. FeNO levels among current smokers increased even at 4°C, although the values among ex-smokers decreased gradually, and those among nonsmokers remained stable. The rate of increase was significantly higher among current smokers than among nonsmokers and ex-smokers from 9 hours after collection onwards.

Conclusions

Storage at 4°C could prolong the stability of FeNO levels after collection. This result suggests that valid measurements can be performed within several days if the samples are stored at 4°C. However, the time course of the changes in FeNO levels differed in relation to initial FeNO values and cigarette smoking.