Sputum eosinophilia and the short term response to inhaled mometasone in chronic obstructive pulmonary disease

Monitoring COPD patients: systemic and bronchial eosinophilic inflammation in a 2-year follow-up

BACKGROUND

High blood eosinophils seem to predict exacerbations and response to inhaled corticosteroids (ICS) treatment in patients with chronic obstructive pulmonary disease (COPD). The aim of our study was to prospectively evaluate for 2 years, blood and sputum eosinophils in COPD patients treated with bronchodilators only at recruitment.

METHODS

COPD patients in stable condition treated with bronchodilators only underwent monitoring of lung function, blood and sputum eosinophils, exacerbations and comorbidities every 6 months for 2 years. ICS was added during follow-up when symptoms worsened.

RESULTS

63 COPD patients were enrolled: 53 were followed for 1 year, 41 for 2 years, 10 dropped-out. After 2 years, ICS was added in 12/41 patients (29%) without any statistically significant difference at time points considered. Blood and sputum eosinophils did not change during follow-up. Only FEV1/FVC at T0 was predictive of ICS addition during the 2 year-follow-up (OR:0.91; 95% CI: 0.83-0.99, p = 0.03). ICS addition did not impact on delta (T24-T0) FEV1, blood and sputum eosinophils and exacerbations. After 2 years, patients who received ICS had higher blood eosinophils than those in bronchodilator therapy (p = 0.042). Patients with history of ischemic heart disease increased blood eosinophils after 2 years [p = 0.03 for both percentage and counts].

CONCLUSIONS

Blood and sputum eosinophils remained stable during the 2 year follow-up and were not associated with worsened symptoms or exacerbations. Almost 30% of mild/moderate COPD patients in bronchodilator therapy at enrollment, received ICS for worsened symptoms in a 2 year-follow-up and only FEV1/FVC at T0 seems to predict this addition. History of ischemic heart disease seems to be associated with a progressive increase of blood eosinophils.

The association of blood eosinophil counts and FEV1 decline: a cohort study

BACKGROUND

Accelerated lung function decline is characteristic of COPD. However, the association between blood eosinophil counts and lung function decline, accounting for current smoking status, in young individuals without prevalent lung disease is not fully understood.

METHODS

This is a cohort study of 629 784 Korean adults without COPD or a history of asthma at baseline who participated in health screening examinations including spirometry and differential white blood cell counts. We used a linear mixed-effects model to estimate the annual change in forced expiratory volume in 1 s (FEV1) (mL) by baseline blood eosinophil count, adjusting for covariates including smoking status. In addition, we performed a stratified analysis by baseline and time-varying smoking status.

RESULTS

During a mean follow-up of 6.5 years (maximum 17.8 years), the annual change in FEV1 (95% CI) in participants with eosinophil counts <100, 100-199, 200-299, 300-499 and ≥500 cells·µL-1 in the fully adjusted model were -23.3 (-23.9--22.7) mL, -24.3 (-24.9--23.7) mL, -24.8 (-25.5--24.2) mL, -25.5 (-26.2--24.8) mL and -26.8 (-27.7--25.9) mL, respectively. When stratified by smoking status, participants with higher eosinophil count had a faster decline in FEV1 than those with lower eosinophil count in both never- and ever-smokers, which persisted when time-varying smoking status was used.

CONCLUSIONS

Higher blood eosinophil counts were associated with a faster lung function decline among healthy individuals without lung disease, independent of smoking status. The findings suggest that higher blood eosinophil counts contribute to the risk of faster lung function decline, particularly among younger adults without a history of lung disease.

Clinical utilization of airway inflammatory biomarkers in the prediction and monitoring of clinical outcomes in patients with chronic obstructive pulmonary disease

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) accounts for 545 million people living with chronic respiratory disorders and is the third leading cause of morbidity and mortality around the world. COPD is a progressive disease, characterized by episodes of acute worsening of symptoms such as cough, dyspnea, and sputum production.

AREAS COVERED

Airway inflammation is a prominent feature of COPD. Chronic airway inflammation results in airway structural remodeling and emphysema. Persistent airway inflammation is a treatable trait of COPD and plays a significant role in disease development and progression. In this review, the authors summarize the current and emerging biomarkers that reveal the heterogeneity of airway inflammation subtypes, clinical outcomes, and therapeutic response in COPD.

EXPERT OPINION

Airway inflammation can be broadly categorized as eosinophilic (type 2 inflammation) and non-eosinophilic (non-type 2 inflammation) in COPD. Currently, blood eosinophil counts are incorporated in clinical practice guidelines to identify COPD patients who are at a higher risk of exacerbations and lung function decline, and who are likely to respond to inhaled corticosteroids. As new therapeutics are being developed for the chronic management of COPD, it is essential to identify biomarkers that will predict treatment response.

Glucocorticoid Use in Patients Hospitalized with Chronic Obstructive Pulmonary Disease Exacerbations

Objective of the Study

Systemic glucocorticoid therapy can improve the outcomes of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). The study tried to investigate the use of glucocorticoids in AECOPD patients and the factors associated with the physicians' choice.

Methodology

Patients with AECOPD over two periods were divided by the year of 2017 when GOLD and ERS/ATS Guideline for COPD were updated. Data of patients regarding the study was retrieved from medical records. Descriptive statistical analysis was used for the illustration of glucocorticoids use, and hypothesis testing for comparison over the periods.

Results

Between 2010 and 2016, the proportion of ICS use was 522/640 (81.6%) and 341/452 (75.4%) between 2017 and 2020. COPD severity (GOLD C/D classification), bronchial asthma, percentage of neutrophils, and higher PaCO2 were factors associated with physicians' prescription of systemic glucocorticoids between 2010 and 2016. While the use of ICS at the stable stage, counts of neutrophils, and higher PaCO2 were influencing factors between 2017 and 2020. Over the two periods, 1-year recurrent rate decreased from 32.4% to 20.9%, with a significant statistical difference (P<0.001).

Conclusion

The optimized use of glucocorticoids was found after the publishment of 2017 ERS/ATS Guideline for COPD, this improvement was associated with a decreased 1-year recurrence rate among AECOPD patients at our institution, underscoring the positive impact of guideline updates on patient outcomes.

How inhaled corticosteroids target inflammation in COPD

Inhaled corticosteroids (ICS) are the most commonly used anti-inflammatory drugs for the treatment of COPD. COPD has been previously described as a "corticosteroid-resistant" condition, but current clinical trial evidence shows that selected COPD patients, namely those with increased exacerbation risk plus higher blood eosinophil count (BEC), can benefit from ICS treatment. This review describes the components of inflammation modulated by ICS in COPD and the reasons for the variation in response to ICS between individuals. There are corticosteroid-insensitive inflammatory pathways in COPD, such as bacteria-induced macrophage interleukin-8 production and resultant neutrophil recruitment, but also corticosteroid-sensitive pathways including the reduction of type 2 markers and mast cell numbers. The review also describes the mechanisms whereby ICS can skew the lung microbiome, with reduced diversity and increased relative abundance, towards an excess of proteobacteria. BEC is a biomarker used to enable the selective use of ICS in COPD, but the clinical outcome in an individual is decided by a complex interacting network involving the microbiome and airway inflammation.

[Eosinophilic chronic obstructive pulmonary disease: A review]

Over the past decades, chronic obstructive pulmonary disease (COPD) has become a major public health problem due to increasing morbidity and mortality. COPD is characterized by airflow limitation due to inflammation of the bronchial tree and remodeling of the small airways. In 20-40% of patients with COPD, eosinophilic inflammation of the airways is observed, as in bronchial asthma. Eosinophilic COPD has recently been shown to be a distinct disease and is associated with more pronounced airway remodeling. Although the role of eosinophils in the pathogenesis of COPD is not fully understood, the level of eosinophils can be used in the prognosis and administration of corticosteroids, and their effectiveness is higher in eosinophilia. Currently, monoclonal antibodies directed against interleukins (IL-5, IL-4 and IL-13) or their receptors are being tested in the T2 endotype of COPD. This review focuses on the mechanisms of eosinophilia in COPD, the use of blood and sputum eosinophils as a biomarker, and the advisability of using monoclonal antibodies in the treatment of eosinophilic COPD.

[Diagnosis and treatment of asthma: a guideline for respiratory specialists 2023 - published by the German Respiratory Society (DGP) e. V.]

The management of asthma has fundamentally changed during the past decades. The present guideline for the diagnosis and treatment of asthma was developed for respiratory specialists who need detailed and evidence-based information on the new diagnostic and therapeutic options in asthma. The guideline shows the new role of biomarkers, especially blood eosinophils and fractional exhaled NO (FeNO), in diagnostic algorithms of asthma. Of note, this guideline is the first worldwide to announce symptom prevention and asthma remission as the ultimate goals of asthma treatment, which can be achieved by using individually tailored, disease-modifying anti-asthmatic drugs such as inhaled steroids, allergen immunotherapy or biologics. In addition, the central role of the treatment of comorbidities is emphasized. Finally, the document addresses several challenges in asthma management, including asthma treatment during pregnancy, treatment of severe asthma or the diagnosis and treatment of work-related asthma.

Management of eosinophil-associated inflammatory diseases: the importance of a multidisciplinary approach

Elevated eosinophil counts in blood and tissue are a feature of many pathological processes. Eosinophils can migrate and accumulate in a wide variety of tissues and, by infiltrating a target organ, can mediate the development of several inflammatory diseases. The normalization of eosinophilia is a common biomarker of a treatable trait and can also be used as a prognostic and predictive biomarker since it implies a reduction in type 2 inflammation that contributes to disease pathogenesis. Biological therapies targeting this cell type and its proinflammatory mediators have been shown to be effective in the management of a number of eosinophilic diseases, and for this reason they constitute a potential common strategy in the treatment of patients with various multimorbidities that present with type 2 inflammation. Various biological options are available that could be used to simultaneously treat multiple target organs with a single drug, bearing in mind the need to offer personalized treatments under the umbrella of precision medicine in all patients with eosinophil-associated diseases (EADs). In addition to reviewing these issues, we also discuss a series of perspectives addressing the management of EAD patients from a multidisciplinary approach, with the collaboration of health professionals from different specialties who manage the different multimorbidities that frequently occur in these patients. We examine the basic principles of care that this multidisciplinary approach must cover and present a multidisciplinary expert opinion regarding the ideal management of patients with EADs, from diagnosis to therapeutic approach and follow-up.

Time-Updated Phenotypic Guidance of Corticosteroids and Antibiotics in COPD: Rationale, Perspective and a Proposed Method

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease with distinct phenotypes, each having distinct treatment needs. Eosinophilic airway inflammation is present in a subset of COPD patients in whom it can act as a driver of exacerbations. Blood eosinophil counts are a reliable way to identify patients with an eosinophilic phenotype, and these measurements have proven to be successful in guiding the use of corticosteroids in moderate and severe COPD exacerbations. Antibiotic use in COPD patients induces a risk of Clostridium difficile infection, diarrhea, and antibiotic resistance. Procalcitonin could possibly guide antibiotic treatment in patients admitted with AECOPD. Current studies in COPD patients were successful in reducing exposure to antibiotics with no changes in mortality or length of stay. Daily monitoring of blood eosinophils is a safe and effective way to reduce oral corticosteroid exposure and side effects for acute exacerbations. No evidence on time-updated treatment guidance for stable COPD exists yet, but a current trial is testing an eosinophil-guided approach on inhaled corticosteroid use. Procalcitonin-guided antibiotic treatment in AECOPD shows promising results in safely and substantially reducing antibiotic exposure both in time-independent and time-updated algorithms.

Further evidence of a type 2 inflammatory signature in chronic obstructive pulmonary disease or emphysema

BACKGROUND

There is increasing recognition of a type 2 (T2) inflammatory pattern in a subset of patients with chronic obstructive pulmonary disease (COPD) or emphysema, characterized by blood and airway eosinophilia. The mechanism underlying this is not well established. The recognition that CD125 (interleukin [IL]-5 receptor alpha) is expressed on some lung neutrophils and eosinophils in patients with asthma led us to speculate that CD125 may also be expressed on lung neutrophils in patients with COPD or emphysema.

OBJECTIVE

To interrogate the expression of CD125 on lung neutrophils (and, when present, eosinophils) in patients with COPD/emphysema and identify a meaningful biomarker to predict neutrophil CD125 expression, including other markers of T2 inflammation.

METHODS

We obtained blood and bronchoalveolar lavage (BAL) samples from patients with physician-diagnosed COPD/emphysema undergoing a clinically indicated bronchoscopy.

RESULTS

We found that a highly variable percentage of BAL neutrophils indeed expressed surface CD125 (0%-78.7%), with obvious clustering of CD125high and CD125low patterns. No correlation was found with clinical characteristics, blood or BAL eosinophil or neutrophil counts, BAL cytokines, or BAL eosinophil CD125 expression.

CONCLUSION

We conclude that, similar to asthma, lung neutrophils from patients with COPD display interleukin-5 receptor alpha (CD125) on their surface. This along with the frequent presence of IL-4 and IL-5 in airway fluid further suggests a possible role of the T2 pathway in contributing to COPD severity.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03984799.

Inhaled corticosteroids versus placebo for stable chronic obstructive pulmonary disease

BACKGROUND

The role of inhaled corticosteroids (ICS) in chronic obstructive pulmonary disease (COPD) has been the subject of much uncertainty. COPD clinical guidelines currently recommend selective use of ICS. ICS are not recommended as monotherapy for people with COPD, and are only given in combination with long-acting bronchodilators due to greater efficacy of combination therapy. Incorporating and critiquing newly published placebo-controlled trials into the monotherapy evidence base may help to resolve ongoing uncertainties and conflicting findings about their role in this population.

OBJECTIVES

To evaluate the benefits and harms of inhaled corticosteroids, used as monotherapy versus placebo, in people with stable COPD, in terms of objective and subjective outcomes.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was October 2022.

SELECTION CRITERIA

We included randomised trials comparing any dose of any type of ICS, given as monotherapy, with a placebo control in people with stable COPD. We excluded studies of less than 12 weeks' duration and studies of populations with known bronchial hyper-responsiveness (BHR) or bronchodilator reversibility.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our a priori primary outcomes were 1. exacerbations of COPD and 2. quality of life. Our secondary outcomes were 3. all-cause mortality, 4. lung function (rate of decline of forced expiratory volume in one second (FEV₁)), 5. rescue bronchodilator use, 6. exercise capacity, 7. pneumonia and 8. adverse events including pneumonia. ]. We used GRADE to assess certainty of evidence.

MAIN RESULTS

Thirty-six primary studies with 23,139 participants met the inclusion criteria. Mean age ranged from 52 to 67 years, and females were 0% to 46% of participants. Studies recruited across the severities of COPD. Seventeen studies were of duration longer than three months and up to six months and 19 studies were of duration longer than six months. We judged the overall risk of bias as low.  Long-term (more than six months) use of ICS as monotherapy reduced the mean rate of exacerbations in those studies where pooling of data was possible (generic inverse variance analysis: rate ratio 0.88 exacerbations per participant per year, 95% confidence interval (CI) 0.82 to 0.94; I² = 48%, 5 studies, 10,097 participants; moderate-certainty evidence; pooled means analysis: mean difference (MD) -0.05 exacerbations per participant per year, 95% CI -0.07 to -0.02; I² = 78%, 5 studies, 10,316 participants; moderate-certainty evidence). ICS slowed the rate of decline in quality of life, as measured by the St George's Respiratory Questionnaire (MD -1.22 units/year, 95% CI -1.83 to -0.60; I² = 0%; 5 studies, 2507 participants; moderate-certainty evidence; minimal clinically importance difference 4 points). There was no evidence of a difference in all-cause mortality in people with COPD (odds ratio (OR) 0.94, 95% CI 0.84 to 1.07; I² = 0%; 10 studies, 16,636 participants; moderate-certainty evidence). Long-term use of ICS  reduced the rate of decline in FEV₁ in people with COPD (generic inverse variance analysis: MD 6.31 mL/year benefit, 95% CI 1.76 to 10.85; I² = 0%; 6 studies, 9829 participants; moderate-certainty evidence; pooled means analysis: 7.28 mL/year, 95% CI 3.21 to 11.35; I² = 0%; 6 studies, 12,502 participants; moderate-certainty evidence).

ADVERSE EVENTS

in the long-term studies, the rate of pneumonia was increased in the ICS group, compared to placebo, in studies that reported pneumonia as an adverse event (OR 1.38, 95% CI 1.02 to 1.88; I² = 55%; 9 studies, 14,831 participants; low-certainty evidence). There was an increased risk of oropharyngeal candidiasis (OR 2.66, 95% CI 1.91 to 3.68; 5547 participants) and hoarseness (OR 1.98, 95% CI 1.44 to 2.74; 3523 participants). The long-term studies that measured bone effects generally showed no major effect on fractures or bone mineral density over three years. We downgraded the certainty of evidence to moderate for imprecision and low for imprecision and inconsistency.

AUTHORS' CONCLUSIONS

This systematic review updates the evidence base for ICS monotherapy with newly published trials to aid the ongoing assessment of their role for people with COPD. Use of ICS alone for COPD likely results in a reduction of exacerbation rates of clinical relevance, probably results in a reduction in the rate of decline of FEV₁ of uncertain clinical relevance and likely results in a small improvement in health-related quality of life not meeting the threshold for a minimally clinically important difference. These potential benefits should be weighed up against adverse events (likely to increase local oropharyngeal adverse effects and may increase the risk of pneumonia) and probably no reduction in mortality. Though not recommended as monotherapy, the probable benefits of ICS highlighted in this review support their continued consideration in combination with long-acting bronchodilators. Future research and evidence syntheses should be focused in that area.

COPD: Providing the right treatment for the right patient at the right time

Chronic Obstructive Pulmonary Disease (COPD) is a common disease associated with significant morbidity and mortality that is both preventable and treatable. However, a major challenge in recognizing, preventing, and treating COPD is understanding its complexity. While COPD has historically been characterized as a disease defined by airflow limitation, we now understand it as a multi-component disease with many clinical phenotypes, systemic manifestations, and associated co-morbidities. Evidence is rapidly emerging in our understanding of the many factors that contribute to the pathogenesis of COPD and the identification of "early" or "pre-COPD" which should provide exciting opportunities for early treatment and disease modification. In addition to breakthroughs in our understanding of the origins of COPD, we are optimizing treatment strategies and delivery of care that are showing impressive benefits in patient-centered outcomes and healthcare utilization. This special issue of Respiratory Medicine, "COPD: Providing the Right Treatment for the Right Patient at the Right Time" is a summary of the proceedings of a conference held in Stresa, Italy in April 2022 that brought together international experts to discuss emerging evidence in COPD and Pulmonary Rehabilitation in honor of a distinguished friend and colleague, Claudio Ferdinando Donor (1948-2021). Claudio was a true pioneer in the field of pulmonary rehabilitation and the comprehensive care of individuals with COPD. He held numerous leadership roles in in the field, provide editorial stewardship of several respiratory journals, authored numerous papers, statement and guidelines in COPD and Pulmonary Rehabilitation, and provided mentorship to many in our field. Claudio's most impressive talent was his ability to organize spectacular conferences and symposia that highlighted cutting edge science and clinical medicine. It is in this spirit that this conference was conceived and planned. These proceedings are divided into 4 sections which highlight crucial areas in the field of COPD: (1) New concepts in COPD pathogenesis; (2) Enhancing outcomes in COPD; (3) Non-pharmacologic management of COPD; and (4) Optimizing delivery of care for COPD. These presentations summarize the newest evidence in the field and capture lively discussion on the exciting future of treating this prevalent and impactful disease. We thank each of the authors for their participation and applaud their efforts toward pushing the envelope in our understanding of COPD and optimizing care for these patients. We believe that this edition is a most fitting tribute to a dear colleague and friend and will prove useful to students, clinicians, and researchers as they continually strive to provide the right treatment for the right patient at the right time. It has been our pleasure and a distinct honor to serve as editors and oversee such wonderful scholarly work.

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.

Heterogeneity of asthma-chronic obstructive pulmonary disease (COPD) overlap from a cohort of patients with severe asthma and COPD

BACKGROUND

A considerable proportion of patients have features of both asthma and chronic obstructive pulmonary disease (COPD) simultaneously, called asthma-COPD overlap (ACO).

OBJECTIVES

The aim of this study was to identify heterogeneity of ACO from a cohort of patients with severe asthma and COPD using the same diagnostic criteria.

DESIGN

We used the International Severe Asthma Registry (ISAR) and the Korean COPD Subgroup Study (KOCOSS) to evaluate clinical characteristics of ACO from each cohort.

METHODS

We classified subjects into four groups: (1) pure severe asthma, (2) ACO from the severe asthma cohort, (3) ACO from the COPD cohort, and (4) pure COPD. ACO was defined by satisfying extreme bronchodilator response (BDR) >15% and 400 ml and/or blood eosinophil count ⩾300 /µL in patients aged 40 years or older and post-BD forced expiratory volume in 1 s (FEV₁)/forced vital capacity (FVC) ratio <0.7.

RESULTS

The ACO group had 25 (23%) of 111 in the ISAR cohort and 403 (23%) of 1781 in the KOCOSS cohort. The ACO from the COPD cohort was older with more males and more smokers, but had similar degree of airflow limitation compared with the ACO from the severe asthma cohort. ICS-containing inhaler treatment was prescribed for all severe asthma subjects, but only for 43.9% of ACO subjects from the COPD cohort. Compared with patients having pure severe asthma, the risk for exacerbation was comparable in ACO either from severe asthma or COPD cohort [adjusted odds ratio (aOR): 1.54, 95% CI: 0.22-10.95 or aOR: 2.15, 95% CI: 0.59-7.85].

CONCLUSION

The prevalence of ACO was similar in severe asthma and COPD cohorts applying identical diagnostic criteria. ACO from the severe asthma cohort was similar to ACO from the COPD cohort in terms of lung function and exacerbation risk.

Measurement of Blood Eosinophils in Asthma and Chronic Obstructive Pulmonary Disease

Eosinophils are important effector cells in airway inflammation, as pleiotropy and heterogeneity can be linked to various pathophysiologies in asthma and chronic obstructive pulmonary disease (COPD). Sputum eosinophils can reflect the heterogeneity of airway inflammation, and owing to their traits, blood eosinophils can be a surrogate and potential biomarker for managing both conditions. Blood eosinophils are activated via the stimulation of type 2 cytokines, such as interleukin (IL)-5, IL-4/13, granulocyte-macrophage colony-stimulating factor, IL-33, and thymic stromal lymphopoietin. There is sufficient evidence to support the relationship between the blood eosinophil count and clinical outcomes, including pulmonary function decline, exacerbations, all-cause mortality, and treatment response to inhaled corticosteroids and biologics. Thus, there is growing interest in the use of blood eosinophils for the management of these diseases. Compiling recent evidence, we herein review the significance of measuring blood eosinophils in asthma and COPD.

Blood Eosinophils and Clinical Outcomes in Inpatients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Prospective Cohort Study

Purpose

The prognostic value of blood eosinophils in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) remains controversial. This study aimed to evaluate whether blood eosinophils could predict in-hospital mortality and other adverse outcomes in inpatients with AECOPD.

Methods

The patients hospitalized for AECOPD were prospectively enrolled from ten medical centers in China. Peripheral blood eosinophils were detected on admission, and the patients were divided into eosinophilic and non-eosinophilic groups with 2% as the cutoff value. The primary outcome was all-cause in-hospital mortality.

Results

A total of 12,831 AECOPD inpatients were included. The non-eosinophilic group was associated with higher in-hospital mortality than the eosinophilic group in the overall cohort (1.8% vs 0.7%, P < 0.001), the subgroup with pneumonia (2.3% vs 0.9%, P = 0.016) or with respiratory failure (2.2% vs 1.1%, P = 0.009), but not in the subgroup with ICU admission (8.4% vs 4.5%, P = 0.080). The lack of association still remained even after adjusting for confounding factors in subgroup with ICU admission. Being consistent across the overall cohort and all subgroups, non-eosinophilic AECOPD was also related to greater rates of invasive mechanical ventilation (4.3% vs 1.3%, P < 0.001), ICU admission (8.9% vs 4.2%, P < 0.001), and, unexpectedly, systemic corticosteroid usage (45.3% vs 31.7%, P < 0.001). Non-eosinophilic AECOPD was associated with longer hospital stay in the overall cohort and subgroup with respiratory failure (both P < 0.001) but not in those with pneumonia (P = 0.341) or ICU admission (P = 0.934).

Conclusion

Peripheral blood eosinophils on admission may be used as an effective biomarker to predict in-hospital mortality in most AECOPD inpatients, but not in patients admitted into ICU. Eosinophil-guided corticosteroid therapy should be further studied to better guide the administration of corticosteroids in clinical practice.

Circulating eosinophil levels and lung function decline in stable chronic obstructive pulmonary disease: a retrospective longitudinal study

OBJECTIVE

Whether blood eosinophils (bEOS) in chronic obstructive pulmonary disease (COPD) are associated with disease progression is a topic of debate. We aimed to evaluate whether the differential white blood cell (WBC) count, symptoms and treatment may predict lung function decline and exacerbations in COPD patients.

METHODS

We retrospectively examined stable COPD patients with a minimum follow-up of 3 years at our outpatients' clinic. We collected information about lung volumes (FEV1, FVC), the total and differential WBC count, acute exacerbations of COPD (number in the 12 months before the beginning of the study=AE-COPD-B, and during the follow-up=AE-COPD-F), smoking status and treatment. FEV1 decline and AE-COPD-F were described by using a generalized linear model and a 2-level random intercept negative binomial regression, respectively. The models included eosinophil and neutrophil counts as potential predictors and were adjusted by sex, age, smoking status, AE-COPD-B, treatment with bronchodilators and inhaled corticosteroids (ICS).

RESULTS

Sixty-eight patients were considered, 36 bEOS- (<170 cells/μL, the median value) and 32 bEOS+ (≥170 cells/μL). ∆FEV1 was higher in bEOS+ than bEOS- (34.86 mL/yr vs 4.49 mL/yr, p=0.029). After adjusting for potential confounders, the eosinophil count was positively (β=19.4; CI 95% 2.8, 36.1; p=0.022) and ICS negatively (β=-57.7; CI 95% -91.5,-23.9; p=0.001) associated with lung function decline. bEOS were not found to be associated with the number of AE-COPD-F.

CONCLUSION

In stable COPD patients, a higher level of blood eosinophils (albeit in the normal range) predicts a greater FEV1 decline, while ICS are associated with a slower progression of airflow obstruction.

Blood and sputum eosinophilia in COPD exacerbation

Background

Exacerbations in chronic obstructive pulmonary disease (COPD) are major contributors to worsening lung function, impaired quality of life, emergency healthcare use, and COPD-related mortality. COPD exacerbations are heterogeneous in terms of airway inflammation and etiology.

Objectives

To assess the relation between blood and sputum eosinophils and COPD exacerbation.

Subjects and methods

Prospective cohort study, conducted on 100 COPD patients presented in outpatient clinic. All patients were subjected to medical history including: occupational history, smoking history, comorbidity, number of exacerbations in last year and their degree, history of admission in the last year and treatment taken for COPD. Modified Medical Research Council scale of dyspnea, peak expiratory flow rate, oxygen saturation using pulse oximetry. Complete blood count with differential eosinophilic count. Sputum sample differential cell count was done.

Results

The eosinophil level in blood before and after treatment showed a significant positive correlation with the number of hospital admission in the last year (r = 0.29; P = 0.003 and r = 0.3; P = 0.002, respectively). Regarding the eosinophil level either in blood or in sputum, it showed significant statistical elevation in patients not using steroid treatment in comparison to patients who used systemic or inhaled steroid treatments (P < 0.001 and 0.004, respectively).

Conclusion

Blood eosinophil count can be used as a severity marker of COPD exacerbations. The eosinophil levels, either in blood or sputum, were significantly correlated with the degree of exacerbation. Sputum eosinophilia can also predict the risk of hospitalization. In addition, blood eosinophil count can direct the use of oral corticosteroids in exacerbation.

Inhaled Corticosteroids in Adults with Non-cystic Fibrosis Bronchiectasis: From Bench to Bedside. A Narrative Review

Due to their potent anti-inflammatory capacity (particularly in predominantly eosinophilic inflammation) and immunosuppressive properties, inhaled corticosteroids (ICSs) are widely used in asthmatic patients and also in individuals with chronic obstructive pulmonary disease (COPD) who suffer multiple exacerbations or have peripheral eosinophilia. However, there is little evidence for their use in non-cystic fibrosis bronchiectasis (hereafter, bronchiectasis). According to data extracted from large databases of bronchiectasis in adults, ICSs are used in more than 50% of patients without any scientific evidence to justify their efficacy and contrary to the recommendations of international guidelines on bronchiectasis that generally advise against their use. Indeed, bronchiectasis is a disease with predominantly neutrophilic inflammation and a high likelihood of chronic bacterial bronchial infection. Furthermore, it is known that due to their immunosuppressive properties, ICSs can induce an increase in bacterial infections. This manuscript aims to review the basic properties of ICSs, how they impact bronchiectasis in adults, the current position of international guidelines on this treatment, and the current indications and future challenges related to ICS use in bronchiectasis.

Identification of COPD Inflammatory Endotypes Using Repeated Sputum Eosinophil Counts

Higher blood and sputum eosinophil counts are associated with a greater response to corticosteroids in COPD. Low blood eosinophil counts exhibit greater stability over time whereas higher counts demonstrate more variability. Stability of airway eosinophil levels is less well understood. We have studied the stability of sputum eosinophil counts. Differential cell count data for COPD patients (n = 100) were analysed. Subjects with two sputum eosinophil counts, 6 months apart, were included in the analysis. Patients were stratified based on baseline sputum eosinophil count into ‘low’, ‘intermediate’ and ‘high’ groups: eosinophilLOW (<1%), eosinophilINT (1−3%) and eosinophilHIGH (≥3%). Sputum eosinophil counts showed good stability (rho = 0.61, p < 0.0001, ICC of 0.77), with 67.4% of eosinophilLOW patients remaining in the same category on repeat sampling. Bland−Altman analysis of the whole cohort (median difference between measurements = 0.00%, 90th percentile = −1.4 and 4.7%) showed greater variation at higher counts. This was confirmed by the wider 90th centiles in the eosinophilINT (−1.50 to 5.65) and eosinophilHIGH groups (−5.33 to 9.80) compared to the eosinophilLOW group (−0.40 to 1.40). The repeatability of sputum eosinophil counts was related to the baseline eosinophil count; sputum eosinophilLOW COPD patients were relatively stable over time, while the eosinophilHIGH group showed greater variability. These results can facilitate the identification of COPD endotypes with differential responses to treatment.

Fractional Exhaled Nitric Oxide Guided-Therapy in Chronic Obstructive Pulmonary Disease: A Stratified, Randomized, Controlled Trial

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) with eosinophilic airway inflammation represents a distinct phenotype that might respond to treatment with inhaled corticosteroids. Fractional exhaled nitric oxide (FENO) might predict eosinophilic inflammation and guide treatment option. We hypothesized that COPD patients with different baseline levels of FENO might have differentiated response to treatment with salmeterol/fluticasone (SFC) or tiotropium (TIO).

METHODS

This open-label, randomized-controlled trial enrolled treatment-naïve COPD patients who were stratified into high- (≥23.5ppb) and low-FENO group, followed by 12-week treatment with SFC or TIO. A linear mixed model with repeated measures was applied to analyze the changes in FENO (primary outcome), COPD assessment test (CAT) score, FEV₁, and parameters in induced sputum and blood after treatment.

RESULTS

134 patients were divided into 4 subgroups: low-FENO/SFC (n=30), low-FENO/TIO (n=29), high-FENO/SFC (n=37), and high-FENO/TIO (n=38). At baseline, FENO 23.5ppb clearly differentiated between eosinophilic and non-eosinophilic inflammation groups based on the eosinophils in induced sputum and blood. FENO significantly correlated with sputum and blood eosinophils at baseline. High-FENO/SFC (vs. high-FENO/TIO) subgroup had significant reduction in FENO and sputum inflammation profiles (including eosinophils, macrophages, matrix metalloproteinase-9, and interlukin-8) after treatment. These differences were not replicated between low-FENO/SFC and low-FENO/TIO subgroups. The improvement in CAT and FEV₁ after treatment was indiscriminate between SFC and TIO in the low- and high-FENO groups.

CONCLUSION

High baseline FENO can serve as an indicator of eosinophilic airway inflammation in COPD patients who may respond favorably to treatment with inhaled corticosteroids/long-acting β₂-agonists.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT02546349.

Predictors of High Sputum Eosinophils in Chronic Obstructive Pulmonary Disease

BACKGROUND

Eosinophils are involved in the development of chronic obstructive pulmonary disease (COPD) and inhaled corticosteroid responsiveness. We evaluated clinical predictors of high sputum eosinophil levels in a COPD cohort in China.

METHODS

We conducted an observational, prospective, population-based, cross-sectional study. Participants were tested for COPD and underwent spirometry, computed tomography scans, and a blood test. Participants also produced induced sputum and responded to an information-gathering questionnaire. High sputum eosinophils were defined as ≥3.0%. Multivariate logistic regression was used to identify predictors of high sputum eosinophil levels.

RESULTS

We recruited 895 patients with complete and quality control data. The median percentage of sputum eosinophil abundance was 2.00% (interquartile range: 0.75-5.00) and the prevalence of COPD with high sputum eosinophils was 38.0%. Covariance analysis indicated that the high sputum eosinophil group had lower lung function, more severe emphysema, and air trapping. Multivariate logistic regression indicated that high blood eosinophil levels, severe respiratory symptoms, being a former smoker, and a family history of respiratory diseases were associated with high sputum eosinophil levels.

CONCLUSION

High blood eosinophil levels, severe respiratory symptoms, being a former smoker, and a family history of respiratory diseases may be predictors of high sputum eosinophil levels in Chinese COPD patients. High sputum eosinophils were associated with lower lung function, more emphysema, and gas trapping.

The Combined Value of Type2 Inflammatory Markers in Chronic Obstructive Pulmonary Disease

The roles of type2 inflammatory markers in chronic airway diseases have been assessed in previous studies. However, the relationship between the combined value of these biomarkers and chronic obstructive pulmonary disease (COPD) has not been fully elucidated. We aimed to investigate the roles of the combined value of the fraction of exhaled nitric oxide (FeNO) level and blood eosinophil count in COPD and the predictive capability of these biomarkers. In total, 266 patients were included in our analysis. When the two type2 biomarkers were assessed separately, there were limited correlations between either increased FeNO level or blood eosinophil count and decreased incidence of total exacerbation or frequency of mild exacerbation. Combining these two biomarkers strengthened their association with both incidence and frequency of acute exacerbation. In addition, during further assessment, simultaneously increased FeNO level and blood eosinophil count were associated with both mild and moderate acute exacerbation. Among the subjects included in this analysis, although the predictive capability was improved when these two biomarkers were combined, the improvement was not statistically significant, indicating the need to increase the sample size. The combination of FeNO level and blood eosinophil count exhibited strong and independent additive value in the assessment of acute exacerbation in COPD; simultaneously increased FeNO level and blood eosinophil count played a protective role in progression of COPD.

Longitudinal changes in forced expiratory volume in 1 s in patients with eosinophilic chronic obstructive pulmonary disease

BACKGROUND

Data on changes in lung function in eosinophilic chronic obstructive pulmonary disease (COPD) are limited. We investigated the longitudinal changes in forced expiratory volume in 1 s (FEV₁) and effects of inhaled corticosteroid (ICS) in Korean COPD patients.

METHODS

Stable COPD patients in the Korean COPD subgroup study (KOCOSS) cohort, aged 40 years or older, were included and classified as eosinophilic and non-eosinophilic COPD based on blood counts of eosinophils (greater or lesser than 300 cells/μL). FEV₁ changes were analyzed over a 3-year follow-up period.

RESULTS

Of 627 patients who underwent spirometry at least twice during the follow up, 150 and 477 patients were classified as eosinophilic and non-eosinophilic, respectively. ICS-containing inhalers were prescribed to 40% of the patients in each group. Exacerbations were more frequent in the eosinophilic group (adjusted odds ratio: 1.49; 95% confidence interval: 1.10-2.03). An accelerated FEV₁ decline was observed in the non-eosinophilic group (adjusted annual rate of FEV₁ change: - 12.2 mL/y and - 19.4 mL/y for eosinophilic and non-eosinophilic groups, respectively). In eosinophilic COPD, the adjusted rate of annual FEV₁ decline was not significant regardless of ICS therapy, but the decline rate was greater in ICS users (- 19.2 mL/y and - 4.5 mL/y, with and without ICS therapy, respectively).

CONCLUSIONS

The annual rate of decline in FEV₁ was favorable in eosinophilic COPD compared to non-eosinophilic COPD, and ICS therapy had no beneficial effects on changes in FEV₁.

The Use of Inhaled Corticosteroids for Patients with COPD Who Continue to Smoke Cigarettes: An Evaluation of Current Practice

The use of inhaled corticosteroids (ICS) in combination with inhaled bronchodilators for patients with chronic obstructive pulmonary disease (COPD) is a common practice in primary care settings. However, ICS-containing therapies may be less effective in patients with COPD compared with asthma, and in individuals with COPD who continue to smoke cigarettes. Preclinical studies suggest that inflammation in COPD is very different from in asthma. Glucocorticoid receptor functioning and other innate anti-inflammatory mechanisms are altered in cells exposed to cigarette smoke. COPD may be relatively insensitive to ICS, especially in individuals who continue to smoke. ICS-containing therapies in patients with asthma who continue to smoke may also be less effective compared with patients who do not smoke. ICS-containing therapies may be inappropriately used in some patients with COPD, and their long-term use is associated with an increased risk for side effects, including pneumonia and bone fractures in some patients. Treatment for patients with COPD should be carefully evaluated, and anti-inflammatory/bronchodilatory strategies should be chosen based on individual patient characteristics and recommendations in current guidelines.

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.

Blood eosinophils in COPD: friend or foe?

INTRODUCTION

The pathogenesis of chronic obstructive pulmonary disease (COPD) is highly complex and the underlying cellular and molecular mechanisms remain poorly understood.

AREAS COVERED

COPD has been traditionally associated with neutrophilic inflammation of the bronchi, but in the last decade, studies have demonstrated that eosinophils may also migrate into the lower airways of patients with COPD and their increased numbers can be noticed during exacerbations as well as stable disease. In this review, we present clinical characteristics of eosinophilic COPD, as well as the role of eosinophils as a biomarker-guided therapy in COPD. A systematic research using the database of Pubmed up to February 2021 was performed. The terms we searched were eosinophilic inflammation, COPD, COPD phenotypes, COPD exacerbations, corticosteroids in COPD, and monoclonal antibodies in COPD.

EXPERT OPINION

Blood eosinophil levels show strong potential as a prognostic and theragnostic biomarker in the clinical management of COPD being at the moment the most reliable biomarker. The lack of a certain cutoff value of blood eosinophils as guidance for treatment with ICS and biologic therapies and the uncertainty regarding the stability of eosinophilia and eosinophilic phenotype through the course of COPD remain as unmet dilemmas and problems.

An Overview of the Safety and Efficacy of Monoclonal Antibodies for the Chronic Obstructive Pulmonary Disease

Several mAbs have been tested or are currently under clinical evaluation for the treatment of COPD. They can be subdivided into those that aim to block specific pro-inflammatory and pro-neutrophilic cytokines and chemokines, such as TNF-α, IL-1β, CXCL8 and IL-1β, and those that act on T2-mediated inflammation, respectively, by blocking IL-5 and/or its receptor, preventing IL-4 and IL-13 signaling, affecting IL-33 pathway and blocking TSLP. None of these approaches has proved to be effective, probably because in COPD there is no dominant cytokine or chemokine and, therefore, a single mAb cannot be effective on all pathways. With a more in-depth understanding of the numerous pheno/endotypic pathways that play a role in COPD, it may eventually be possible to identify those specific patients in whom some of these cytokines or chemokines might predominate. In this case, it will be possible to implement a personalized treatment, but the use of each mAb will only be reserved for a very limited number of subjects.

Eosinophilia and fractional exhaled nitric oxide levels in chronic obstructive lung disease

Introduction

COPD is a heterogeneous disorder with varied phenotypes. We aimed to determine the prevalence of asthma history, peripheral eosinophilia and elevated FeNO levels along with the diagnostic utility of peripheral eosinophilia in identifying airway eosinophilic inflammation.

Methods

National Health and Nutrition Examination Survey data were analysed for the study period 2007–2010. Subjects aged ≥40 years with postbronchodilator FEV₁/FVC ratio <0.70 were included. Receiver operator curve analysis was performed for sensitivity analysis. A p value of <0.001 is considered statistically significant.

Results

A total of 3 110 617 weighted COPD cases were identified; predominantly male (64.4%) and non-Hispanic whites (86.1%). Among our COPD subjects, 14.6% had a history of doctor diagnosed asthma, highest among females and other race Americans. The overall prevalence of peripheral eosinophilia is 36%, 38.3% among COPD subjects with asthma history, and 35.6% among COPD without asthma history. The overall prevalence of elevated FeNO ≥25 ppb is 14.3%; 28.7% among COPD subjects with asthma history and 13.0% among COPD without asthma history.

Discussion

The prevalence of FeNO levels ≥25 ppb and peripheral eosinophilia was significantly higher among COPD subjects with asthma compared with COPD without asthma history. Not all COPD subjects with peripheral eosinophilia and elevated FeNO levels have a reported history of asthma. Our study supports clinically phenotyping COPD subjects with eosinophilic inflammation be independent of their asthma history and peripheral eosinophilia can be used as a surrogate marker in resource-limited settings.

Anti-asthma and antitussive effects of a fermented extract of a mixture of Ramulus mori, Anthriscus sylvestris, and Salvia plebeian

Respiratory immunity is getting more important recently due to outbreak of respiratory diseases and increasing the concentration of fine dust. The aim of this study was to investigate respiratory protection effect of a fermented extract of medicinal plants (FEMP) containing Ramulus mori, Salvia plebeia, and Anthriscus sylvestris. The expression levels of IL-8 and IL-17 in LPS/poly-L-arginine (PLA) and FEMP-cotreated A549 cells were lower than those in LPS/PLA only-treated cells. The levels of IgE, IL-17, and IL-4 in the bronchoalveolar lavage fluid (BALF) and serum of FEMP-treated mice with ovalbumin/LPS-induced asthma were lower than the control levels. The lung inflammation score and the number of inflammatory cells in the BALF decreased by FEMP treatment. In the citric acid-induced coughing guinea pig, the FEMP treatment decreased the number of coughs. Therefore, FEMP shows anti-asthmatic and antitussive activities without hepatotoxicity and can be used as a compound aiming to improve respiratory health.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-021-00955-3.

Mepolizumab for Eosinophil-Associated COPD: Analysis of METREX and METREO

Background

A pre-specified meta-analysis of individual patient data from the 52-week METREX and METREO trials, which investigated mepolizumab for chronic obstructive pulmonary disease (COPD) in patients with blood eosinophil counts ≥150 cells/µL (screening) or ≥300 cells/µL (prior year) and frequent exacerbations, enables more robust characterization of mepolizumab efficacy in COPD and exploration of the relationship between blood eosinophil count and treatment responses.

Methods

In METREX (117106/NCT02105948) and METREO (117113/NCT02105961), randomized patients received mepolizumab or placebo added to existing inhaled corticosteroid (ICS)–based triple maintenance therapy. The annual rate of moderate/severe exacerbations (primary endpoint) was compared between subcutaneous (SC) mepolizumab 100 mg versus placebo (primary comparison of interest) and all doses (100 mg and 300 mg SC) versus placebo in patients with blood eosinophil counts ≥150 cells/µL at screening or ≥300 cells/µL in the prior year. Secondary/other endpoints included time to first moderate/severe exacerbation, exacerbations leading to emergency department visit/hospitalization and health-related quality of life (HRQoL). A predictive model of the relationship between screening blood eosinophil counts and exacerbation rates included data from all randomized patients.

Results

In total, 1510 patients were randomized in METREX and METREO and 1136 patients were included in the pre-specified meta-analysis. From the meta-analysis, mepolizumab 100 mg SC significantly reduced annual moderate/severe exacerbation rates versus placebo by 18% (rate ratio: 0.82; 95% confidence interval: 0.71, 0.95; p=0.006) and delayed time to first moderate/severe exacerbation (hazard ratio: 0.80 [0.68, 0.94]; p=0.006). Mepolizumab 100 mg SC versus placebo numerically reduced exacerbations leading to ED visits/hospitalization and improved HRQoL. A modelling approach demonstrated increasing efficacy for moderate/severe exacerbations with increasing screening blood eosinophil count; this relationship was more pronounced for exacerbations requiring oral corticosteroids (post hoc). The all-doses comparison had similar results.

Conclusion

Mepolizumab reduces exacerbations in patients with eosinophil-associated COPD. Results suggest that blood eosinophil counts (≥150 cells/µL at screening or ≥300 cells/µL in the prior year) allow for identification of patients with COPD who experience exacerbations while treated with maximal ICS-based triple maintenance therapy who are likely to benefit from mepolizumab.

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Lung macrophages drive mucus production and steroid-resistant inflammation in chronic bronchitis

Background

Patients with chronic obstructive pulmonary disease (COPD) frequently suffer from chronic bronchitis (CB) and display steroid-resistant inflammation with increased sputum neutrophils and macrophages. Recently, a causal link between mucus hyper-concentration and disease progression of CB has been suggested.

Methods

In this study, we have evaluated the steroid sensitivity of purified, patient-derived sputum and alveolar macrophages and used a novel mechanistic cross-talk assay to examine how macrophages and bronchial epithelial cells cross-talk to regulate MUC5B production.

Results

We demonstrate that sputum plug macrophages isolated from COPD patients with chronic bronchitis (COPD/CB) are chronically activated and only partially respond to ex vivo corticosteroid treatment compared to alveolar macrophages isolated from lung resections. Further, we show that pseudo-stratified bronchial epithelial cells grown in air–liquid-interface are inert to direct bacterial lipopolysaccharide stimulation and that macrophages are able to relay this signal and activate the CREB/AP-1 transcription factor complex and subsequent MUC5B expression in epithelial cells through a soluble mediator. Using recombinant protein and neutralizing antibodies, we identified a key role for TNFα in this cross-talk.

Conclusions

For the first time, we describe ex vivo pharmacology in purified human sputum macrophages isolated from chronic bronchitis COPD patients and identify a possible basis for the steroid resistance frequently seen in this population. Our data pinpoint a critical role for chronically activated sputum macrophages in perpetuating TNFα-dependent signals driving mucus hyper-production. Targeting the chronically activated mucus plug macrophage phenotype and interfering with aberrant macrophage-epithelial cross-talk may provide a novel strategy to resolve chronic inflammatory lung disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01762-4.

Burden of illness in blood eosinophilic phenotype COPD patients in New Zealand

BACKGROUND

Real-world data on eosinophilic chronic obstructive pulmonary disease (COPD)'s clinical burden, in exacerbating/stable states, and the stability of blood eosinophil count (BEC) measurements are limited. We described measured BEC distributions among general practice COPD patients in New Zealand (NZ).

METHODS

This retrospective cohort study utilized the NZ-HealthStat primary care database. Participants were aged ≥40 years, with ≥1 BEC 6 months following a COPD diagnosis code during 2011-2012. Descriptive analyses included examinations of BEC stability and association with COPD exacerbations/treatments/comorbidities.

RESULTS

The most frequent COPD comorbidity was asthma (n = 1180/2909, 40.56%). Among COPD patients: 65% had BECs >150 cells/μL; 35% had BECs >300 cells/μL (non-mutually exclusive threshold categories). Treatment patterns were similar, except for more frequent inhaled corticosteroid (ICS)/long-acting beta₂-agonist use in COPD patients with asthma history (51%) than those without (31%). Factors associated with BECs >150 cells/μL in participants without ICS treatment included Māori/Pacific ethnicity, obesity, oral corticosteroid (OCS) use, and exacerbation history. When stratified by asthma history, ICS treatment, and neutrophil count above/below 5000 cells/μL, geometric mean BECs ranged from 136.70 to 398.52 cells/μL. Exploratory analyses showed a fair-good COPD/BEC measurement stability over 12 months.

CONCLUSIONS

Asthma was a common COPD comorbidity in NZ, particularly in Māori/Pacific patients. No overall relationship was observed between BEC/COPD exacerbations, which may reflect background ICS confounding. However, analyses in non-ICS treated participants suggested that Māori/Pacific patients with obesity and COPD, OCS treatment, exacerbation history, and/or elevated BECs are at the highest risk of COPD exacerbations. One BEC measurement appears a good indicator of a patient's BECs over time.

ACO (Asthma-COPD Overlap) Is Independent from COPD, a Case in Favor: A Systematic Review

Asthma and chronic obstructive pulmonary disease (COPD) are now recognized to be able to co-exist as asthma-COPD overlap (ACO). It is clinically relevant to evaluate whether patients with COPD concurrently have components of asthma in primary care. This is because: (i) ACO is a relatively common condition among asthma (over 40 years of age) or COPD irrespective of its diagnosis criteria; (ii) patients with ACO can have higher frequency of exacerbation and more rapid decline in lung function than those with asthma or COPD; and (iii) asthmatic features such as eosinophilic airway inflammation are promising indicators for prediction of inhaled corticosteroid-responsiveness in COPD. The aim of this review to evaluate diagnostic markers for ACO. We searched PubMed for articles related to ACO published until 2020. Articles associated with diagnostic biomarkers were included. We identified a total of 25 studies, some of which have revealed that a combination of biomarkers such as fractional exhaled nitric oxide and serum immunoglobulin E is useful to discern type 2 inflammation in the airways of COPD. Here, we review the current understanding of the clinical characteristics, biomarkers and molecular pathophysiology of ACO in the context of how ACO can be differentiated from COPD.

Targeted therapy in eosinophilic chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a common and preventable airway disease causing significant worldwide mortality and morbidity. Lifetime exposure to tobacco smoking and environmental particles are the two major risk factors. Over recent decades, COPD has become a growing public health problem with an increase in incidence. COPD is defined by airflow limitation due to airway inflammation and small airway remodelling coupled to parenchymal lung destruction. Most patients exhibit neutrophil-predominant airway inflammation combined with an increase in macrophages and CD8⁺ T-cells. Asthma is a heterogeneous chronic inflammatory airway disease. The most studied subtype is type 2 (T2) high eosinophilic asthma, for which there are an increasing number of biologic agents developed. However, both asthma and COPD are complex and share common pathophysiological mechanisms. They are known as overlapping syndromes as approximately 40% of patients with COPD present an eosinophilic airway inflammation. Several studies suggest a putative role of eosinophilia in lung function decline and COPD exacerbation. Recently, pharmacological agents targeting eosinophilic traits in uncontrolled eosinophilic asthma, especially monoclonal antibodies directed against interleukins (IL-5, IL-4, IL-13) or their receptors, have shown promising results. This review examines data on the rationale for such biological agents and assesses efficacy in T2-endotype COPD patients.

Patients with severe COPD and eosinophilic inflammation experience uncontrolled symptoms despite optimal pharmaceutical treatment. The development of new biomarkers is needed for better phenotyping of patients to propose innovative targeted therapy.https://bit.ly/2KzWuNO

Pharmacological treatment of stable chronic obstructive pulmonary disease

Pharmacological treatment for chronic obstructive pulmonary disease (COPD) aims to alleviate symptoms and reduce the future risk of events such as exacerbations, disease progression and death. The heterogeneity of COPD results in variable responses to pharmacological interventions. COPD treatment has evolved towards a precision medicine approach, integrating clinical and biomarker information in order to optimize treatment decisions for each individual. The evidence supporting the use of blood eosinophil counts to predict responses to inhaled corticosteroids (ICS) in COPD patients has led to the adoption of this biomarker for use in clinical practice. The development of novel double and triple inhaled combination treatments containing long-acting bronchodilators with or without ICS has involved some landmark randomized controlled trials in COPD patients. These studies have provided valuable evidence to direct the use of different classes of combination treatments. However, there are still some unresolved questions and debates. This review article describes the advances in the pharmacological treatment of COPD, particularly the personalization of treatment. The evidence base for current recommendations is discussed, and controversial issues are dissected.

The different phenotypes of COPD

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with significant morbidity and mortality. To improve the health status and reduce symptom burden, it is important to identify a group of patients with similar characteristics and prognosis, called clinical phenotypes. Herein we shall review the different phenotypes of COPD.

SOURCES OF DATA

Keywords (COPD, phenotype, acute exacerbation) search was conducted in PubMed, Google Scholar.

AREAS OF AGREEMENT

Those with raised blood eosinophil counts respond better to steroid therapy at stable state and exacerbation.

AREAS OF CONTROVERSY

There is no universally accepted blood eosinophil cut-off value that will indicate favourable response to corticosteroids and potentially for future biologic therapy.

GROWING POINTS

There is an urgent need for further therapeutic options for COPD patients with non-eosinophilic inflammation.

AREAS TIMELY FOR DEVELOPING RESEARCH

Well-designed COPD trials with identification of phenotypes for more personalization of the treatment of COPD.

Blood Eosinophil Levels and Prognosis of Hospitalized Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

BACKGROUD

Studies about the clinical significance of high eosinophil levels in chronic obstructive pulmonary disease (COPD) are conflicting, and it has been less studied in hospitalized patients with acute exacerbation of COPD (AECOPD).This study was to examine blood eosinophil levels in relation to the prognosis of hospitalized patients with AECOPD.

METHODS

This was a retrospective cohort study of patients with AECOPD as their primary diagnosis and admitted to Beijing Shijitan Hospital, Capital Medical University, from January 2010 to December 2016. The patients were assigned according to the count of eosinophil in peripheral blood at their first hospitalization. Patients were grouped as ≤100, 100-300, and ≥300 eosinophils/µL of peripheral blood. The use of glucocorticoids, duration of hospitalization, in-hospital mortality, and re-hospitalization were examined.

RESULTS

Compared with the 100-300 eosinophils/µL group, the ≤100 eosinophils/µL group showed higher frequencies of fever, respiratory failure, and the use of systemic glucocorticoids. Eosinophil counts were not associated with in-hospital mortality and duration of hospitalization. The multivariable analysis showed that GOLD3/4 (odds ratio (OR)=2.04, 95%CI: 1.20-3.44, P = 0.008), systemic glucocorticoids (OR=1.84, 95%CI: 1.41-2.98, P = 0.012), mechanical ventilation (OR=2.66, 95%CI: 1.36-5.18, P = 0.004), and acute exacerbation in the past year before hospitalization (OR=2.03, 95%CI: 1.27-3.23, P = 0.003) were independently associated with acute exacerbation within 1 year after discharge. Eosinophil count was not associated with acute exacerbation within 1 year after discharge.

CONCLUSIONS

Peripheral blood eosinophil counts are not associated with the 1-year AECOPD prognosis.

Using Blood Eosinophil Count as a Biomarker to Guide Corticosteroid Treatment for Chronic Obstructive Pulmonary Disease

Treating patients hospitalised with acute exacerbations of chronic obstructive pulmonary disease (COPD) usually involves administering systemic corticosteroids. The many unwanted side effects associated with this treatment have led to increased interest in minimising the accumulated corticosteroid dose necessary to treat exacerbations. Studies have shown that short-term treatment with corticosteroids is preferred, and recent trials have shown that biomarkers can be used to further reduce exposure to corticosteroids. Interestingly, high eosinophil counts in patients with acute exacerbations of COPD are indicative of an eosinophilic phenotype with a distinct response to treatment with corticosteroids. In addition, post-hoc analysis of randomised control trials have shown that higher blood eosinophil counts at the start of the study predict a greater response to inhaled corticosteroids in stable COPD. In this review, we examine the studies on this topic, describe how blood eosinophil cell count may be used as a biomarker to guide treatment with corticosteroids, and identify some relevant challenges.

Richness of sputum microbiome in acute exacerbations of eosinophilic chronic obstructive pulmonary disease

BACKGROUND

The eosinophilic chronic obstructive pulmonary disease (COPD) is known to be more sensitive to corticosteroid. The sputum microbiome has been shown to affect COPD prognosis, but its role in acute exacerbations of eosinophilic COPD is unclear. This study aimed to investigate the dynamic changes of the airway microbiome in patients with acute exacerbations of eosinophilic COPD.

METHODS

Fifty-seven patients with acute exacerbations of COPD from the First Affiliated Hospital of Guangxi Medical University between June 2017 and June 2018 were divided into two groups. Patients with eosinophils ≥300 cells/μL in the peripheral venous blood were assigned to the eosinophilic group (Eos) and the rest to the non-eosinophilic group (Noneos). All patients received similar treatment including inhaled budesonide according to the guidelines. The induced sputum microbiome was analyzed on the 1st and 7th day of treatment using the 16S ribosomal RNA (rRNA) method. The levels of interleukin (IL)-6 and IL-8 were measured in the plasma and the sensitivity to corticosteroids was determined in isolated peripheral blood mononuclear cells. Quantitative data were compared between the two groups using the independent samples t test or Mann-Whitney U test. Categorical data were evaluated using Chi-squared test or Fisher's exact test.

RESULTS

Twenty-six patients were classified into Eos group and 31 patients were classified into Noneos group. Prior to treatment, the alpha diversity (Shannon index) (2.65 ± 0.63 vs. 2.56 ± 0.54, t = 0.328, P = 0.747) and the structure of the sputum microbiome were similar in the Eos group and the Noneos group. After 7 days of treatment, alpha diversity increased in both groups, while the microbiome richness (Ace index) was significantly lower in the Eos group (561.87 ± 109.13 vs. 767.88 ± 148.48, t = -3.535, P = 0.002). At the same time, IL-6 (12.09 ± 2.85 pg/mL vs. 15.54 ± 2.45 pg/mL, t = -4.913, P < 0.001) and IL-8 (63.64 ± 21.69 pg/mL vs. 78.97 ± 17.13 pg/mL, t = -2.981, P = 0.004) decreased more significantly in the Eos group, and the percentages of inhibition of IL-8 at dexamethasone concentrations 10 to 10 mol/L were significantly higher in the Eos group than those in the Noneos group (all P < 0.05).

CONCLUSIONS

The induced sputum microbiome richness decreased more significantly following treatment in the Eos patients compared to the Noneos patients. The lower plasma inflammatory factor levels and the higher percentage of inhibition of IL-8 might be due to higher corticosteroid sensitivity in Eos patients.

Benefits and Risks of Inhaled Corticosteroid Treatment in Patients with Chronic Obstructive Pulmonary Disease Classified by Blood Eosinophil Counts

BACKGROUND

Chronic obstructive pulmonary disease (COPD) typically includes neutrophilic airway inflammation and eosinophilic inflammation in some cases. Inhaled corticosteroid (ICS) suppresses eosinophilic inflammation of the airway and reduces acute exacerbation (AE). The present study investigated the relationship between ICS and AE in patients with COPD classified by blood eosinophil counts.

METHODS

Overall, 244 patients with COPD were retrospectively evaluated between 2014 and 2017 and classified into two groups based on blood eosinophil counts (≥ 300/μL and < 300/μL). These patients were then reclassified into subgroups of those with and without ICS. Differences in the characteristics and incidence of AE and pneumonia with AE in each subgroup were evaluated retrospectively.

RESULTS

All patients with ICS used 320 μg budesonide twice daily. In the group with blood eosinophil counts ≥ 300/μL, patients with ICS had a significantly lower incidence of AE than those without ICS (P = 0.023). Meanwhile, no significant differences were observed in incidence of AE in the group with blood eosinophil counts < 300/μL. In the group with blood eosinophil counts < 300/μL, patients with ICS had a higher incidence of pneumonia with AE (P = 0.009). Conversely, no significant differences were observed in the group with blood eosinophil counts ≥ 300/μL.

CONCLUSIONS

ICS significantly reduced AE in COPD patients with blood eosinophil counts ≥ 300/μL. Meanwhile, ICS significantly increased pneumonia rate in patients with blood eosinophil count < 300/μL. Blood eosinophil count may be a useful indicator to identify the benefits and risks of ICS in COPD.

Association between blood eosinophils with exacerbation and patient-reported outcomes in chronic obstructive pulmonary disease patients in an endemic area for parasitic infections: a prospective study

Background

Eosinophilic chronic obstructive pulmonary disease (COPD) patients have eosinophilic airway inflammation. No prospective study has reported blood eosinophil counts in an endemic area for parasitic infection. The primary objective was to compare exacerbation rates. The secondary objectives were patient-reported outcomes between eosinophilic and non-eosinophilic COPD.

Methods

A prospective study was conducted in COPD patients for 52 weeks. COPD was diagnosed according to GOLD criteria. Blood eosinophil counts were recorded at study entry. Exacerbations were recorded during the entire study period whereas COPD Assessment Test (CAT) and spirometry were recorded at 12 months. The eosinophilic and non-eosinophilic groups were defined by blood eosinophil counts ≥300 and <300 cells/µL, respectively.

Results

A total of 145 COPD patients were included. Fifty-eight (40%) and 87 (60%) patients were eosinophilic and non-eosinophilic COPD and the median [interquartile range (IQR)] eosinophil counts were 481 [378.5, 675] and 149 [101.2, 208] cells/µL, respectively. The median (IQR) annual exacerbation rates were 3 [2, 4] and 2 [2, 2.5] times/year in the eosinophilic and non-eosinophilic groups, respectively (P=0.024). The eosinophilic group had higher admissions (P=0.007) but lower mortality (P=0.041). The patient-reported outcomes were not statistically significantly different between the two groups. Eosinophil counts ≥300 cells/µL identified exacerbation in COPD patients with sensitivity and specificity of 0.71 and 0.64, respectively.

Conclusions

COPD patients with blood eosinophil counts ≥300 cells/µL had more exacerbations and admissions but lower mortality than the non-eosinophilic patients. Blood eosinophil count is an effective biomarker to predict exacerbation risk in endemic parasitic areas.

Trial registration

NCT04123028 at ClinicalTrials.gov.

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.