Asthma and Chronic Obstructive Pulmonary Disease Overlap According to the Japanese Respiratory Society Diagnostic Criteria: The Prospective, Observational ACO Japan Cohort Study

Fractional exhaled nitric oxide distribution and its relevant factors in the general adult population and its healthy subpopulation

Background

Measurement of fractional exhaled nitric oxide (Feno) has been used in the diagnosis and management of asthma. Understanding the distribution of Feno in a larger resident population and its "healthy" subpopulation would contribute to the interpretation of Feno in clinical practice.

Objective

This study aimed to investigate the distribution and its associated factors in the adult population and its healthy subpopulations.

Methods

We conducted a cross-sectional study of 8,638 men and 17,288 women aged 20 years or older living in Miyagi prefecture, Japan. We investigated the distribution of Feno and its associated factors in all subjects, a subpopulation with no history of upper and lower airway diseases (healthy subpopulation 1), and a subpopulation with no history of upper and lower airway diseases, normal lung function, and no positivity for other biomarkers of type 2 inflammation (healthy subpopulation 2).

Results

The distribution of Feno in healthy subpopulations, especially in healthy subpopulation 2 (median [interquartile range], 17 [12-23] with 95th percentile of 36 ppb) was lower than in all subjects (19 [13-26] ppb with 95th percentile of 47 ppb). In healthy subpopulation 1, 10.3% had elevated Feno (≥35 ppb), and elevated Feno was positively associated with factors including obstructive ventilatory defect, blood eosinophilia, house dust mite-specific IgE positivity, and history of hypertension. Male sex was associated with elevated Feno in all subjects and healthy subpopulations.

Conclusion

The distribution of Feno in the healthy subpopulation supports the validity of the criteria (≥35 ppb) currently used in Japan for the diagnosis of asthma.

Associations of fractional exhaled nitric oxide with airway dimension and mucus plugs on ultra-high-resolution computed tomography in former smokers and nonsmokers with asthma

BACKGROUND

Associations of fractional exhaled nitric oxide (FeNO) with airway wall remodeling and mucus plugs remain to be explored in smokers and nonsmokers with asthma. Ultra-high-resolution computed tomography (U-HRCT), which allows accurate structural quantification of airways >1 mm in diameter, was used in this study to examine whether higher FeNO was associated with thicker walls of the 3rd to 6th generation airways and mucus plugging in patients with asthma.

METHODS

The retrospective analyses included consecutive former smokers and nonsmokers with asthma who underwent U-HRCT in a hospital. The ratio of wall area to summed lumen and wall area was calculated as the wall area percent (WA%). Mucus plugging was visually scored.

RESULTS

Ninety-seven patients with asthma (including 59 former smokers) were classified into low (<20 ppb), middle (20-35 ppb), and high (>35 ppb) FeNO groups (n = 24, 26, and 47). In analysis including all patients and subanalysis including nonsmokers or former smokers, WA% in the 6th generation airways was consistently higher in the high FeNO group than in the low FeNO group, whereas WA% in the 3rd to 5th generation airways was not. In multivariable models, WA% in the 6th generation airways and the rate of mucus plugging were higher in the high FeNO group than in the low FeNO group after adjusting for age, sex, body mass index, smoking status, lung volume, and allergic rhinitis presence.

CONCLUSIONS

Higher FeNO may reflect the inflammation and remodeling of relatively peripheral airways in asthma in both former smokers and nonsmokers.

Underdiagnosis of COPD: The Japan COPD Real-World Data Epidemiological (CORE) Study

Purpose

The prevalence of airflow obstruction in Japan is 3.8%-16.9%. This epidemiological study based on a large database aimed to reassess the prevalence of airflow obstruction in Japan and the diagnosis rate of chronic obstructive pulmonary disease (COPD).

Patients and Methods

We used data regarding claims from the health insurance union and health checkups provided by JMDC. The present study included a subgroup of individuals aged ≥40 years who underwent health checkups involving spirometry between January and December 2019. The study endpoints were the prevalence of airflow obstruction, COPD diagnosis rate, disease stage, and respiratory function test results.

Results

Among 102,190 participants, 4113 (4.0%) had airflow obstruction. The prevalence of airflow obstruction was 5.3% in men and 2.1% in women. Among the study population, 6.8% were current smokers, while 3.4% were never or former smokers. Additionally, the prevalence of COPD increased with age. Approximately 8.4% of participants with airflow obstruction were diagnosed with COPD. Regarding the COPD diagnosis status, participants with airflow obstruction who were diagnosed with COPD were at a more advanced stage than those not diagnosed. Finally, patients diagnosed with COPD had significantly lower FEV1/FVC and FEV1 (p < 0.0001; Wilcoxon rank sum test).

Conclusion

The epidemiological study based on a large database determined the COPD diagnosis rate related to airflow obstruction. The COPD diagnosis rate was extremely low among individuals who underwent health checkups, indicating the need for increased awareness about this medical condition. Moreover, primary care physicians should identify patients with suspected COPD and collaborate with pulmonologists to facilitate the early detection of COPD and enhance the COPD diagnosis rate.

Role of bronchial hyperresponsiveness in patients with obstructive sleep apnea with asthma-like symptoms

BACKGROUND

Obstructive sleep apnea (OSA) is one of the major co-morbidities and aggravating factors of asthma. In OSA-complicated asthma, obesity, visceral fat, and systemic inflammation are associated with its severity, but the role of bronchial hyperresponsiveness (BHR) is unclear. We investigated the involvement of BHR and mediastinal fat width, as a measure of visceral fat, with OSA severity in patients with OSA and asthma-like symptoms.

METHODS

Patients with OSA who underwent BHR test and chest computed tomography scan for asthma-like symptoms were retrospectively enrolled. We evaluated the relationship between apnea-hypopnea index (AHI) and PC20 or anterior mediastinal fat width, stratified by the presence or absence of BHR.

RESULTS

OSA patients with BHR (n = 29) showed more obstructive airways and frequent low arousal threshold and lower mediastinal fat width, and tended to show fewer AHI than those without BHR (n = 25). In the overall analysis, mediastinal fat width was significantly positively correlated with AHI, which was significant even after adjustment with age and gender. This was especially significant in patients without BHR, while in OSA patients with BHR, there were significant negative associations between apnea index and airflow limitation, and hypopnea index and PC20.

CONCLUSIONS

Risk factors for greater AHI differed depending on the presence or absence of BHR in OSA patients with asthma-like symptoms. In the presence of BHR, severity of asthma may determine the severity of concomitant OSA.

Sputum microbiota and inflammatory subtypes in asthma, COPD, and its overlap

Background

Airway microbiota in asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) remains unknown.

Objective

This study with ACO-enriched population aimed to clarify airway microbiota in ACO and in mixed granulocytic inflammation, often detected in ACO and chronic airway diseases.

Methods

This is an observational cross-sectional study. Patients with asthma with airflow limitation, ACO, and COPD were enrolled. Blood tests, pulmonary function, exhaled nitric oxide, and sputum tests were conducted. Sputum microbiota was evaluated using the 16S rRNA gene sequencing technique.

Results

A total of 112 patients (13 asthma, 67 ACO, and 32 COPD) were examined. There were no significant differences in α-diversity among the 3 diseases. The relative abundances of phylum Bacteroidetes, class Bacteroidia, and genus Porphyromonas were associated with decreased eosinophilic inflammation, and were significantly lower in ACO than in COPD. In a comparison of sputum inflammatory subtypes, the proportion of Haemophilus was numerically highest in the mixed granulocytic subtype, followed by the neutrophilic subtype. Likewise, the proportion of Haemophilus was the highest in the intermediate-high (2%-8%) sputum eosinophil group and lowest in the severe (≥8%) eosinophil group. Clinically, Haemophilus proportion was associated with sputum symptoms. Finally, the proportion of Streptococcus was associated with higher blood eosinophil counts and most severe airflow limitation.

Conclusions

Bacteroidia and Porphyromonas abundances in sputum are associated with the eosinophil-low phenotype, and ACO may be characterized by a decrease in these taxa. A mild elevation in sputum eosinophil does not preclude the presence of Haemophilus, which should be noted in the management of obstructive airway diseases.

COPD Patients with Asthma Features in Vietnam: Prevalence and Suitability for Personalized Medicine

COPD patients with asthma features usually benefit from inhaled corticosteroids (ICS)-containing regimens, but their burden and diagnostic criteria remain to be established. The aims of this study were to estimate the proportion of patients with asthma features among patients with physician-diagnosed COPD and to investigate differences in clinical characteristics and current medications between COPD patients with asthma features and patients with COPD alone. A cross-sectional study was conducted at two respiratory out-patient clinics at the University Medical Center in Ho Chi Minh City and Bach Mai Hospital in Ha Noi, Vietnam. COPD patients with asthma features were identified by attending physicians following the approach recommended by the GINA/GOLD joint committee. Of the 332 patients screened, 300 were enrolled in the study. The proportion of COPD patients with asthma features was 27.3% (95% confidence interval (95% CI) 22.6-32.6%). COPD patients with asthma features were younger, with higher FEV₁ values, a greater proportion of positive bronchodilator reversibility tests, higher blood eosinophil count, and were more often treated with ICS/LABA (ICS/long-acting bronchodilator beta-2 agonist) than patients with COPD alone. The prevalence of COPD patients with asthma features is particularly high in Vietnam thus requiring appropriate action plans in clinical practice.

Usefulness of simultaneous impulse oscillometry and spirometry with airway response to bronchodilator in the diagnosis of asthmatic cough

Objective: Some of the most common causes of chronic cough include cough variant asthma (CVA), bronchial asthma (BA), and asthma-COPD overlap (ACO). Although there is some overlap in the etiology of these diseases, it is clinically important to attempt an early differential diagnosis due to treatment strategies and prognoses.Methods: Spirometry and impulse oscillometry (IOS) before and after bronchodilator inhalation were analyzed for clinically diagnosed CVA (cCVA, n = 203), BA (cBA, n = 222), and ACO (cACO, n = 61).Results: A significant difference in ΔFEV₁ was observed between cBA and cCVA (ΔFEV₁ improvement of 122.5 mL/5.4% and 65.7 mL/2.2%, respectively), but no difference was observed in ΔPEF, ΔV50, or ΔV25. Except for R20 (resistance at 20 Hz), significant differences between the three groups were observed in IOS. In IOS, cCVA and cBA showed comparable peripheral airway response to bronchodilator which was thought to be commensurate with changes in V50 and V25. cACO improved ΔFEV₁ improvement of 81.0 mL/6.2% and was distinguished by a downward respiratory system reactance (Xrs) waveform with a limited bronchodilator response. FEV₁/FVC, %FEV₁, and %V25 had relatively strong correlations with the three IOS parameters, X5 (reactance at 5 Hz), resonant frequency (Fres), and low-frequency reactance area (ALX), in the correlation between IOS and spirometers.Conclusion: Changes in IOS parameters were more sensitive in this study than changes in FEV₁ or the flow-volume curve. Considering the benefits and relevance of the two different tests, simultaneous IOS and spirometry testing were useful in the diagnosis of asthmatic cough.

Questionnaire for diagnosing asthma-COPD overlap in COPD: Development of ACO screening questionnaire (ACO-Q)

BACKGROUND

The considerable prevalence and worse outcomes of asthma-COPD overlap (ACO) in COPD have been reported, and optimal introduction of ICS is essential for ACO. However, diagnostic criteria for ACO consist of multiple laboratory tests, which is challenging during this COVID-19 era. The purpose of this study was to create a simple questionnaire to diagnose ACO in patients with COPD.

METHODS

Among 100 COPD patients, 53 were diagnosed with ACO based on the Japanese Respiratory Society Guidelines for ACO. Firstly, 10 candidate questionnaire items were generated and further selected by a logistic regression model. An integer-based scoring system was generated based on the scaled estimates of items.

RESULTS

Five items, namely a history of asthma, wheezing, dyspnea at rest, nocturnal awakening, and weather- or season-dependent symptoms, contributed significantly to the diagnosis of ACO in COPD. History of asthma was related to FeNO >35 ppb. Two points were assigned to history of asthma and 1 point to other items in the ACO screening questionnaire (ACO-Q), and the area under the receiver operating characteristic curve was 0.883 (95% CI: 0.806-0.933). The best cutoff point was 1 point, and the positive predictive value was 100% at a cutoff of 3 points or higher. The result was reproducible in the validation cohort of 53 patients with COPD.

CONCLUSIONS

A simple questionnaire, ACO-Q, was developed. Patients with scores ≥3 could be reasonably recommended to be treated as ACO, and additional laboratory testing would be recommended for patients with 1 and 2 points.

Practical Recommendations for a Selection of Inhaled Corticosteroids in COPD: A Composite ICO Chart

The use of inhaled corticosteroids (ICS) for the maintenance of bronchodilator treatment in patients with chronic obstructive pulmonary disease (COPD) is controversial. While some patients achieve clinical benefits, such as fewer exacerbations and improved symptoms, others do not, and some experience undesired side effects, such as pneumonia. Thus, we reviewed the evidence related to predictors of ICS therapy treatment response in patients with COPD. The first priority clinical markers when considering the efficacy of ICS are type 2 inflammatory biomarkers, followed by a history of suspected asthma and recurrent exacerbations. It is also necessary to consider any potential infection risk associated with ICS, and several risk factors for pneumonia when using ICS have been clarified in recent years. In this article, based on the evidence supporting the selection of ICS for COPD, we propose an ICS composite that can be added to the COPD (ICO) chart for use in clinical practice. The chart divided the type 2 biomarkers into three ranges and provided recommendations (recommend, consider, and against) by combining the history of suspected asthma, history of exacerbations, and risk of infection.

Real-World Evidence on the Diagnostic and Clinical Characteristics of Asthma in Japanese Patients with COPD: The ACO Japan Cohort Study

Introduction

The ACO Japan Cohort Study, a multicenter observational study, investigated the proportion of patients with chronic obstructive pulmonary disease (COPD) who met the Japanese Respiratory Society (JRS) asthma-COPD overlap (ACO) diagnostic criteria, characteristics of ACO and non-ACO patients, and the patient transitions between ACO/non-ACO diagnosis over 2 years.

Patients and Methods

Patients with COPD were consecutively enrolled between June and December 2018 and followed up continuously for 2 years. All participating study sites were medical institutions where respiratory specialists routinely conducted medical examinations/tests required for ACO diagnosis.

Results

Among 708 patients with COPD, 101 (14.3%), 118 (16.7%), and 125 (17.7%) were diagnosed with ACO at registration, 1 year, and 2 years, respectively. In total, 22.6% of patients lacked the data necessary for ACO diagnosis throughout the 2 years. Among patients who had the necessary data for ACO diagnosis, 24.7% were diagnosed with ACO at 2 years. More ACO patients had moderate or severe exacerbations in the past year than non-ACO patients at registration (15.8% vs 6.3%, p = 0.049) and 1 year (19.4% vs 7.6%, p = 0.025). ACO patients had a greater decrease in mean forced expiratory volume in one second over 2 years than non-ACO patients (-92.0 vs 43.4 mL). Among patients diagnosed with ACO at registration, 21.4% transitioned to non-ACO after 1 year. Conversely, almost all non-ACO patients at registration remained non-ACO after 1 year.

Conclusion

COPD patients with ACO determined by the JRS criteria had a high risk of exacerbations and a rapid decline in respiratory function, indicating that the JRS criteria for ACO are useful for identifying high-risk COPD patients. Testing necessary for ACO diagnosis is insufficiently performed even in real-world clinical practice of COPD specialists.

History of Respiratory Events Prior to a First COPD Diagnosis and Future Exacerbations: A Longitudinal Observational Cohort Database Study in Japan

Background

Little is known about the association between respiratory events prior to diagnosis of chronic obstructive pulmonary disease (COPD) and future clinical outcomes in Japan. We investigated the association between pre-COPD diagnosis respiratory events and the incidence of exacerbations in a cohort of newly diagnosed COPD patients in Japan.

Patients and Methods

Data were retrieved from the JMDC claims database. Patients ≥40 years old with a first COPD diagnosis (≥1 hospitalization or ≥2 outpatient claims for COPD) between 2010 and 2016 were included. The incidence rate (IR) of exacerbations in patients with or without any respiratory event (including lower respiratory tract infection and respiratory failure) in the year preceding diagnosis was compared. A negative binomial model explored the association between pre-diagnosis respiratory event and IR ratio (IRR) of exacerbations.

Results

A total of 20,212 patients newly diagnosed with COPD were identified: 61% male, mean age 55 years (SD 9); of these, 955 (4.7%) had experienced ≥1 respiratory event in the year preceding diagnosis. Median duration of follow-up was 3.3 years during which the IR of exacerbations was 0.31 per patient-year (95% confidence interval [CI] 0.29-0.33) in patients with respiratory event, and 0.11 (95% CI 0.10-0.13) in patients without. The IR for severe exacerbation was nearly 10 times greater in patients with respiratory event versus without. Experiencing respiratory event pre-diagnosis was independently associated with an increased IRR of future moderate-to-severe exacerbation (adjusted IRR, 2.7; 95% CI 2.3-3.1).

Conclusion

Patients experiencing respiratory events in the year preceding COPD diagnosis should be considered at-risk of worse clinical COPD outcomes.

Does the asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) exist? A narrative review from epidemiology and practice

Asthma and chronic obstructive pulmonary disease (COPD) have traditionally been approached as separate entities that must be researched and treated separately. There is growing recognition, however, that a substantial proportion of patients with obstructive lung disease have characteristics of both asthma and COPD (termed the asthma-COPD overlap syndrome (ACOS)). Lung disease experts have difficulty defining ACOS, and many still resist accepting the possibility that asthma and COPD may be linked. It is likely that practicing clinicians may be equally confused about how to identify and treat ACOS. This narrative review aims to clarify concepts of ACOS definition, argues that the best way to understand ACOS is to view the chronic lung disease process longitudinally rather than cross-sectionally, and presents evidence that ACOS can be the end result of the natural history of severe asthma. The review also points out the serious gaps in knowledge regarding therapy for ACOS and presents emerging data supporting the intracellular respiratory pathogen Chlamydia pneumoniae as a possible common etiologic agent in severe asthma and ACOS.

The Response to Biologics is Better in Patients with Severe Asthma Than in Patients with Asthma–COPD Overlap Syndrome

Although biologics have demonstrated to be effective in T2-high asthma patients, there is little experience with these drugs in asthma–COPD overlap (ACO). The aim of this study was to compare the effectiveness of biologics in these two conditions. We included 318 patients (24 ACO and 297 asthma) treated with monoclonal antibodies and followed for at least 12 months. Omalizumab was the most frequently employed biologic agent both in patients with ACO and asthma. Asthma control test (ACT) scores after at least 12 months of biologic therapy were not significantly different between groups. The percentage of patients with ≥1 exacerbation and ≥1 corticosteroid burst was significantly higher in ACO patients (70.8 vs 27.3 and 83.3% vs 37.5%, respectively), whereas the percentage of “controlled” patients (with no exacerbations, no need for corticosteroids and ACT ≥ 20) was significantly lower (16.7% vs 39.7%). In conclusion, this report suggests that patients with ACO treated with biologics reach worse outcomes than asthma patients.

Real-World Status of Medical Care and Treatment of Chronic Obstructive Pulmonary Disease by Respiratory Specialists in Japan

INTRODUCTION

The ACO Registry Study was a multicenter, prospective, observational cohort study aiming to clarify the situation of asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) within the COPD population using the Japanese Respiratory Society (JRS) criteria. We reported the proportion of patients who met the ACO criteria among the COPD population at study registration.

METHODS

Using data collected at registration, we investigated the implementation of each diagnostic examination/test required for ACO diagnosis in the full analysis set. Among patients with data necessary for ACO diagnosis, ACO/non-ACO patients with/without asthma diagnosed by a physician and proportions of inhaled corticosteroid (ICS) treatments for COPD were calculated.

RESULTS

Of 708 patients analyzed, 396 (55.9%) had the data necessary for ACO diagnosis, and 312 (44.1%) did not. The proportions of patients who underwent laboratory and respiratory function tests (peripheral blood eosinophil count [79.8%], fractional exhaled nitric oxide [63.7%], airway reversibility [46.8%], and total immunoglobulin [Ig] E/specific IgE [33.3%]) were lower than those who underwent subjective examinations (perennial allergic rhinitis [100%], asthma before age 40 years [97.2%], and variable/paroxysmal respiratory symptoms [94.5%]). Among patients with the data necessary for ACO diagnosis and without asthma complications according to the physician's diagnosis, 15.1% (33/219) met the ACO criteria. Of patients who met the ACO criteria, 74.3% (75/101) received ICS, and 25.7% (26/101) did not. By comparison, among patients who did not meet the ACO criteria, 35.6% (105/295) were receiving ICS, and 64.4% (190/295) were not.

CONCLUSIONS

The proportion of objective laboratory and physiological tests was lower than expected, despite study sites having the clinical resources for objective tests. Most ACO patients were being treated with ICS as recommended in the JRS treatment guidelines. Attempts should be made to further increase the proper use of ICS among these patients in Japan.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03577795.

Narrative review of current COPD status in Japan

Chronic obstructive pulmonary disease (COPD) causes morbidity and mortality worldwide. Due to the improvement in environmental sanitation and medical care, the general life span has increased in the past decades in Japan. However, many older patients with COPD develop a wide range of comorbidities, and the impairments in the activities of daily living result in frailty and increase social and economic burdens. Population-based studies have shown that the prevalence of COPD is approximately 10% among subjects aged ≥40 years, but more than 80% of COPD patients are underdiagnosed. The Ministry of Health, Labour, and Welfare in Japan proposed the National Health Promotion in the 21st century, termed Health Japan 21 (the second term), in 2013 to prevent the onset and progression of noncommunicable diseases (NCDs), including COPD. The government, medical society, and community have been attempting to increase the recognition of COPD and promote smoking cessation. Additionally, Japanese cohorts have revealed distinct clinical features in Japanese patients with COPD, including lower rates of patient-reported exacerbations, less frequent coexisting cardiovascular disease and metabolic syndrome, and lower use of inhaled corticosteroids in Japan compared to the Western countries. Moreover, the poor adherence to inhaled medications is found in approximately 20% of subjects, and rehabilitation is performed in 26% of hospitalized patients with COPD. Therefore, more efforts should be made to improve adherence and access to pulmonary rehabilitation. Overall, Japanese COPD patients share common clinical and social features with COPD patients in other countries. Further international corroboration may help establish better comprehensive management of the disease.