Prevalence of persistent blood eosinophilia: relation to outcomes in patients with COPD

Reliability of blood eosinophil count in steady-state bronchiectasis

RATIONALE

The baseline value of eosinophils in peripheral blood (BEC) has been associated with different degrees of severity, prognosis and response to treatment in patients with bronchiectasis. It is not known, however, if this basal value remains constant over time.

OBJECTIVES

The aim of this study was to assess whether the BEC remains stable in the long term in patients with bronchiectasis.

METHODS AND MEASUREMENTS

Patients from the RIBRON registry of bronchiectasis diagnosed by computed tomography with at least 2 BEC measurements one year apart were included in the study. Patients with asthma and those taking anti-eosinophilic drugs were excluded. Reliability was assessed using the intra-class correlation coefficient (ICC). A patient with a BEC of at least 300 cells/uL or less than 100 cells/uL was considered eosinophilic or eosinopenic, respectively. Group changes over time were also calculated.

MAIN RESULTS

Seven hundred and thirteen patients were finally included, with a mean age of 66.5 (13.2) years (65.8 % women). A total of 2701 BEC measurements were performed, with a median number of measurements per patient of 4 (IQR: 2-5) separated by a median of 12.1 (IQR: 10.5-14.3) months between two consecutive measurements. The ICC was good (>0.75) when calculated between two consecutive measurements (approximately one year apart) but had dropped significantly by the time of the next annual measurements. Similarly, the change from an eosinophilic or eosinopenic patient to a non-eosinophilic or non-eosinopenic patient, respectively, was less than 30 % during the first year with respect to the baseline value but was close to 50 % in later measurements.

CONCLUSIONS

Given the significant changes observed in the baseline value of the BEC over time, its monitoring is necessary in patients with bronchiectasis in order to more reliably assess its usefulness.

Targeting Type 2 Inflammation and Epithelial Alarmins in Chronic Obstructive Pulmonary Disease: A Biologics Outlook

Chronic obstructive pulmonary disease (COPD) is a complex, heterogeneous, progressive inflammatory airway disease associated with a significant impact on patients' lives, including morbidity and mortality, and significant healthcare costs. Current pharmacologic strategies, including first- and second-line therapies such as long-acting β2-agonists, long-acting muscarinic antagonists, inhaled corticosteroids, phosphodiesterase-4 inhibitors, and macrolides, provide relief to patients with COPD. However, many patients remain symptomatic, with persistent symptoms and/or acute exacerbations and progressive lung function loss. Although neutrophilic inflammation is the most common type of inflammation in COPD, 20-40% of patients with COPD exhibit type 2 inflammation, with roles for CD4+ (cluster of differentiation 4) T-helper cell type 1 cells, type 2 innate lymphoid cells, eosinophils, and alternatively activated macrophages. On the basis of the current limitations of available therapies, a significant unmet need exists in COPD management, including the need for targeted therapies to address the underlying pathophysiology leading to disease progression, such as type 2 inflammation, as well as biomarkers to help select the patients who would most benefit from the new therapies. Significant progress is being made, with evolving understanding of the pathobiology of COPD leading to novel therapeutic targets including epithelial alarmins. In this review, we describe the current therapeutic landscape in COPD, discuss unmet treatment needs, review the current knowledge of type 2 inflammation and epithelial alarmins in COPD, explore potential biomarkers of type 2 inflammation in COPD, and finally provide a rationale for incorporating therapies targeting type 2 inflammation and epithelial alarmins in COPD. Video Abstract available online at www.atsjournals.org.

Inhaled corticosteroids and adverse outcomes among chronic obstructive pulmonary disease patients with community-acquired pneumonia: a population-based cohort study

INTRODUCTION

While inhaled corticosteroids (ICS) may increase pneumonia risk in patients with chronic obstructive pulmonary disease (COPD), the impact of ICS on pneumonia outcomes is debated. We examined whether ICS use is associated with adverse outcomes among COPD patients with community-acquired pneumonia (CAP).

MATERIALS AND METHODS

Population-based cohort study of all COPD patients with an incident hospitalization for CAP between 1997 and 2013 in Northern Denmark. Information on medications, COPD severity, comorbidities, complications, and death was obtained from medical databases. Adjusted risk ratios (aRRs) for pleuropulmonary complications, intensive care unit (ICU) admissions, and 30-day mortality in current and former ICS users were compared with those in non-users, using regression analyzes to handle confounding.

RESULTS

Of 11,368 COPD patients with CAP, 6,073 (53.4%) were current ICS users and 1,733 (15.2%) were former users. Current users had a non-significantly decreased risk of pleuropulmonary complications [2.6%; aRR = 0.82 (0.59-1.12)] compared to non-users (3.2%). This was also observed among former users [2.5%; aRR = 0.77 (0.53-1.12)]. Similarly, decreased risks of ICU admission were observed among current users [aRR = 0.77 (0.57-1.04)] and among former users [aRR = 0.81 (0.58-1.13)]. Current ICS users had significantly decreased 30-day mortality [9.1%; aRR = 0.72 (0.62-0.85)] compared to non-users (12.6%), with a stronger association observed among patients with frequent exacerbations [0.58 (0.39-0.86)]. No significant association was observed among former ICS users [0.89 (0.75-1.05)].

CONCLUSION

Our results suggest a decreased risk of death with ICS use among COPD patients admitted for CAP.

Eosinophil Subtypes in Adults with Asthma and Adults with Chronic Obstructive Pulmonary Disease

Rationale: There is a differential response to eosinophilic modulation between patients with asthma and those with chronic obstructive pulmonary disease (COPD). There is also evidence of different subtypes of eosinophils in murine models. However, no study has compared eosinophil subtypes in individuals with COPD and in those with asthma. Objectives: Study the differences in eosinophils subtypes based in the surface protein expression in COPD patients and asthmatic patients. Methods: We studied 10 stable subjects in each of four groups: subjects with COPD, subjects with asthma, smokers without COPD, and healthy volunteers. Subjects with COPD and those with asthma were matched by age, sex, and FEV1% predicted. The following variables were determined: anthropometrics, smoking, exacerbation history, medication use, lung function, and comorbidities. Using flow cytometry and confocal microscopy from blood samples, we determined differences in eosinophil surface proteins and classified them as 1) resident eosinophils (Siglec-8+CD62L+IL-3Rlo) or 2) inflammatory eosinophils (iEos; Siglec-8+CD62LloIL-3Rhi). IL-5 receptor was also determined. Findings were validated in 59 patients with COPD and in 17 patients with asthma. Measurements and Main Results: Patients with asthma had a higher proportion of iEos (25 ± 15%) compared with those with COPD (0.5 ± 1%), smokers without COPD (0.14 ± 0.24%), and healthy volunteers (0.67 ± 1.72%). In patients with asthma, the proportion of iEos was independent of total eosinophil number. iEos had more IL-5 receptors than resident eosinophils (777.02 ± 124.55 vs. 598.35 ± 318.69; P < 0.01). In patients with COPD, there was no relation between iEos number and inhaled corticosteroid use, disease severity, or exacerbations rate. The findings in patients with COPD and those with asthma were confirmed in validation cohorts. Conclusions: There are differences in the subtypes of circulating eosinophils between patients with asthma and those with COPD. This could have clinical implications in the interpretation of eosinophil significance and the approach to therapy in these patients.

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.

Clinical Implications of Low Absolute Blood Eosinophil Count in the SPIROMICS COPD Cohort

BACKGROUND

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) considers blood eosinophil counts < 100 cells/μL (BEC≤100) in people with COPD to predict poor inhaled corticosteroid (ICS) responsiveness. However, the BEC≤100 phenotype is inadequately characterized, especially in advanced COPD.

RESEARCH QUESTION

Are there differences between GOLD group D patients with high BEC and those with low BEC regarding baseline characteristics and longitudinal outcomes?

STUDY DESIGN AND METHODS

We used multivariable mixed models and logistic regression to contrast clinical characteristics and outcomes of BEC≤100 vs BEC > 100 (BEC100+) in all subjects with COPD (n = 1,414) and GOLD group D subjects (n = 185) not receiving ICS.

RESULTS

We identified n = 485 with BEC≤100 (n = 61 GOLD group D) and n = 929 people with BEC100+ (n = 124 GOLD group D). BEC≤100 status was stable at 6 weeks and approximately 52 weeks (intraclass correlations of 0.78 and 0.71, respectively). Compared with BEC100+, BEC≤100 comprised more women, with greater current smoking, and less frequent childhood asthma. Among all analyzed participants, the two BEC-defined subsets showed similar rates of lung function decline (mean slope, BEC≤100 vs BEC100+, -50 vs -39 mL/y; P = .140), exacerbations (0.40 vs 0.36/y; P = .098), subsequent ICS initiation (2.5% vs 4.4%; P = .071), and mortality (7.8% vs 8.4%; P = .715). However, in GOLD group D, people with BEC≤100 showed higher exacerbation rates within 365 days of enrollment (0.62 vs 0.33/y; P = .002) and total follow-up (1.16 vs 0.83/y; P = .014). They also had greater lung function decline (mean slope of -68 mL/y vs -23 mL/y; P = .036) and had greater emphysema at baseline (voxels < 950 Hounsfield units at total lung capacity of 7.46% vs 4.61%; P = .029).

INTERPRETATION

In non-ICS-treated GOLD group D COPD, people with BEC≤100 had more baseline emphysema, prospective exacerbations, and lung function decline. Our analysis has identified a particularly vulnerable subpopulation of people with COPD, suggesting the need for studies focused specifically on their therapeutic treatment.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT01969344; URL: www.

CLINICALTRIALS

gov.

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.

Stability of Blood Eosinophils in COPD with Multiple Acute Exacerbations Within 1 Year and Its Relationship with Prognosis

Background

The relationship between increased blood eosinophils (EOS) and the prognosis of patients with chronic obstructive pulmonary disease (COPD) remains controversial. We aimed to explore the stability of blood eosinophils in patients with multiple hospitalizations for acute exacerbations of chronic obstructive pulmonary disease (AECOPD) over a 1-year period and its relationship with readmission rates and mortality.

Methods

Prospectively include patients with at least 2 hospitalizations for AECOPD in 1 year between June 2019 and December 2021. Using 150 cells/ul as the cut-off value, the study population was divided into EOS, non-EOS, and fluctuating groups based on the longitudinal stability of blood EOS. The relationship between blood EOS and readmission rate and mortality was analyzed according to the 6-month follow-up after hospital discharge.

Results

A total of 202 patients were included. 48, 108, and 46 patients were in the EOS, non-EOS, and fluctuating groups, respectively. The stability of blood EOS at 1 year was 77.2%. The risk of death was lower in the EOS group compared to the non-EOS group (HR=0.323, 95% CI 0.113-0.930, P =0.036). The risk of readmission was lower in both the EOS group (HR=0.486, 95% CI 0.256-0.923, P =0.027) and the non-EOS group (HR=0.575, 95% CI 0.347-0.954, P = 0.032) than in the fluctuating group.

Conclusion

The blood EOS of COPD patients is relatively stable over 1 year. Patients with consistently high blood EOS had a lower risk of all-cause mortality after discharge; patients with fluctuating blood EOS had a higher risk of readmission.

New Perspectives on Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide; many recent advances have been made in many aspects of the disease. The aim of this article is to illustrate and discuss some of these advances in the management of different types of patients. Large-scale trials have confirmed that long-acting bronchodilator therapy, particularly using the combination of LABA/LAMA, remains the mainstay of COPD treatment, with special attention being paid to careful selection of inhaler devices. The initial choice of pharmacological therapy is based on the GOLD ABCD grouping of patients. It is very important to stress that there is a need to implement a management cycle because COPD is a chronic disease with varying clinical course and a high number of potential comorbidities that may affect morbidity and mortality. Therefore, regular reevaluation of the patient is mandatory. This allows identification of characteristics aimed at maximizing the benefits for a specific patient or a subset of patients. Within this context, the role of the blood eosinophil count as a marker of inhaled corticosteroids response to prevent future exacerbations in patients who, despite appropriate bronchodilator therapy, still suffer from them has been proven to be a useful simple biomarker in medication selection. These advances support the concept of precision medicine, with the goal that patients get the right medicine at the right time for the right reason. Finally, recent studies have shown that early life events may be of critical relevance for the development of COPD. With this as a background, concepts to identify individuals at risk and early identification of cases have become an important objective of current research with the hope of maximizing the effects of therapy and the possibility of impacting disease progression.

Blood Eosinophils and Exhaled Nitric Oxide: Surrogate Biomarkers of Airway Eosinophilia in Stable COPD and Exacerbation

In recent years, tremendous efforts have been devoted to characterizing the inflammatory processes in chronic obstructive pulmonary disease (COPD) in order to provide more personalized treatment for COPD patients. While it has proved difficult to identify COPD-specific inflammatory pathways, the distinction between eosinophilic and non-eosinophilic airway inflammation has gained clinical relevance. Evidence has shown that sputum eosinophil counts are increased in a subset of COPD patients and that these patients are more responsive to oral or inhaled corticosteroid therapy. Due to feasibility issues associated with sputum cell profiling in daily clinical practice, peripheral blood eosinophil counts and fractional exhaled nitric oxide levels have been evaluated as surrogate biomarkers for assessing the extent of airway eosinophilia in COPD patients, both in stable disease and acute exacerbations. The diagnostic value of these markers is not equivalent and depends heavily on the patient’s condition at the time of sample collection. Additionally, the sensitivity and specificity of these tests may be influenced by the patient’s maintenance treatment. Overall, eosinophilic COPD may represent a distinct disease phenotype that needs to be further investigated in terms of prognosis and treatment outcomes.

Type 2 inflammation in asthma and other airway diseases

Chronic inflammatory airway diseases, including asthma, chronic rhinosinusitis, eosinophilic COPD and allergic rhinitis are a global health concern. Despite the coexistence of these diseases and their common pathophysiology, they are often managed independently, resulting in poor asthma control, continued symptoms and poor quality of life. Understanding disease pathophysiology is important for best treatment practice, reduced disease burden and improved patient outcomes.

The pathophysiology of type 2 inflammation is driven by both the innate immune system triggered by pollutants, viral or fungal infections involving type 2 innate lymphoid cells (ILC2) and the adaptive immune system, triggered by contact with an allergen involving type 2 T-helper (Th2) cells. Both ILC2 and Th2 cells produce the type-2 cytokines (interleukin (IL)-4, IL-5 and IL-13), each with several roles in the inflammation cascade. IL-4 and IL-13 cause B-cell class switching and IgE production, release of pro-inflammatory mediators, barrier disruption and tissue remodelling. In addition, IL-13 causes goblet-cell hyperplasia and mucus production. All three interleukins are involved in trafficking eosinophils to tissues, producing clinical symptoms characteristic of chronic inflammatory airway diseases.

Asthma is a heterogenous disease; therefore, identification of biomarkers and early targeted treatment is critical for patients inadequately managed by inhaled corticosteroids and long-acting β-agonists alone. The Global Initiative for Asthma guidelines recommend add-on biological (anti IgE, IL-5/5R, IL-4R) treatments for those not responding to standard of care. Targeted therapies, including omalizumab, mepolizumab, reslizumab, benralizumab, dupilumab and tezepelumab, were developed on current understanding of the pathophysiology of type 2 inflammation. These therapies offer hope for improved management of type 2 inflammatory airway diseases.

Asthma is a heterogenous disease. Targeted therapies have been developed based on the pathophysiology of type 2 inflammation. These therapies offer hope for improved management of type 2 inflammatory airway diseases.https://bit.ly/3HCkrvQ

Blood Eosinophils and Chronic Obstructive Pulmonary Disease: A GOLD Science Committee 2022 Review

COPD is a heterogeneous condition. Some patients benefit from treatment with inhaled corticosteroids (ICS) but this requires a precision medicine approach, based on clinical characteristics (phenotyping) and biological information (endotyping) in order to select patients most likely to benefit. The GOLD 2019 report recommended using exacerbation history combined with blood eosinophil counts (BEC) to identify such patients. Importantly, the relationship between BEC and ICS effects is continuous; no / small effects are observed at lower BEC, with increasing effects at higher BEC. The GOLD 2022 report has added additional evidence and recommendations concerning the use of BEC in COPD in clinical practice. Notably, associations have been demonstrated in COPD patients between higher BEC and increased levels of type-2 inflammation in the lungs. These differences in type-2 inflammation can explain the differential ICS response according to BEC. Additionally, lower BEC are associated with greater presence of proteobacteria, notably haemophilus, and increased bacterial infections and pneumonia risk. These observations support management strategies that use BEC to help identify subgroups with increased ICS response (higher BEC) or increased risk of bacterial infection (lower BEC). Recent studies in younger individuals without COPD have also shown that higher BEC are associated with increased risk of FEV1 decline and the development of COPD. Here we discuss and summarise the GOLD 2022 recommendations concerning the use of BEC as a biomarker that can facilitate a personalised management approach in COPD.

Advances in inhaled corticosteroids for the treatment of chronic obstructive pulmonary disease: what is their value today?

INTRODUCTION

As of today, there is still a need to determine which COPD patients may benefit from ICS therapy, whether ICSs are useful in COPD patients without chronic bronchitis, and whether long-acting bronchodilators can reduce the risk of exacerbations in frequent exacerbators even if ICSs are not used, and whether combination therapy including ICSs is helpful in infrequent exacerbators to optimise the use of ICSs in COPD. Nevertheless, in recent years, a fair amount of evidence has been produced that, at least in part, can help define the role of ICSs in COPD better.

AREAS COVERED

Herein, the authors provide an overview of current use of ICS in COPD and discuss their value to the current treatment armamentarium. The article includes discussion of which patients will benefit best from the use of ICSs, their potential uses and adverse effects.

EXPERT OPINION

There is growing agreement on why, in whom, and when ICS therapy can be used in COPD, although the consensus is still lacking because of the heterogeneity of COPD. The use of blood eosinophil counts (BECs) is only helpful in T2 inflammation, while there is a lack of biomarkers indicating the presence of T1 and T17 immunity, which is poorly responsive to ICS. Identifying ICS-sensitive endotypes using specific biomarkers that have yet to be identified and validated is likely to demonstrate that ICSs can influence the natural course of COPD in at least a subset of patients.

[Take-home messages from the COPD 2021 biennial of the French Society of Respiratory Diseases. Understanding to so as to better innovate]

INTRODUCTION

The first COPD biennial organized by the French Society of Respiratory Diseases (SPLF) took place on 17 December 2021.

STATE OF THE ART

The objective of the biennial was to discuss current knowledge regarding COPD pathophysiology, current treatments, research development, and future therapeutic approaches.

PERSPECTIVES

The different lecturers laid emphasis on the complexity of pathophysiologic mechanisms including bronchial, bronchiolar and parenchymal alterations, and also dwelt on the role of microbiota composition in COPD pathenogenesis. They pointed out that addition to inhaled treatments, ventilatory support and endoscopic approaches have been increasingly optimized. The development of new therapeutic pathways such as biotherapy and cell therapy (stem cells…) call for further exploration.

CONCLUSIONS

The dynamism of COPD research was repeatedly underlined, and needs to be further reinforced, the objective being to "understand so as to better innovate" so as to develop effective new strategies for treatment and management of COPD.

Ebselen abolishes vascular dysfunction in influenza A virus-induced exacerbations of cigarette smoke-induced lung inflammation in mice

People with chronic obstructive pulmonary disease (COPD) are susceptible to respiratory infections which exacerbate pulmonary and/or cardiovascular complications, increasing their likelihood of death. The mechanisms driving these complications remain unknown but increased oxidative stress has been implicated. Here we investigated whether influenza A virus (IAV) infection, following chronic cigarette smoke (CS) exposure, worsens vascular function and if so, whether the antioxidant ebselen alleviates this vascular dysfunction. Male BALB/c mice were exposed to either room air or CS for 8 weeks followed by inoculation with IAV (Mem71, 1 × 104.5 pfu). Mice were treated with ebselen (10 mg/kg) or vehicle (5% w/v CM-cellulose in water) daily. Mice were culled 3- and 10-days post-infection, and their lungs lavaged to assess inflammation. The thoracic aorta was excised to investigate endothelial and smooth muscle dilator responses, expression of key vasodilatory and oxidative stress modulators, infiltrating immune cells and vascular remodelling. CS increased lung inflammation and caused significant vascular endothelial dysfunction, which was worsened by IAV infection. CS-driven increases in vascular oxidative stress, aortic wall remodelling and suppression of endothelial nitric oxide synthase (eNOS) were not affected by IAV infection. CS and IAV infection significantly enhanced T cell recruitment into the aortic wall. Ebselen abolished the exaggerated lung inflammation, vascular dysfunction and increased T cell infiltration in CS and IAV-infected mice. Our findings showed that ebselen treatment abolished vascular dysfunction in IAV-induced exacerbations of CS-induced lung inflammation indicating it may have potential for the treatment of cardiovascular comorbidities seen in acute exacerbations of COPD (AECOPD).

Characterization of Eosinophilic Bronchiectasis: A European Multicohort Study

Rationale: Bronchiectasis is classically considered a neutrophilic disorder, but eosinophilic subtypes have recently been described. Objectives: To use multiple datasets available through the European Multicentre Bronchiectasis Audit and Research Collaboration to characterize eosinophilic bronchiectasis as a clinical entity focusing on the impact of eosinophils on bronchiectasis exacerbations. Methods: Patients were included from five countries to examine the relationships between blood eosinophil counts and clinical phenotypes after excluding coexisting asthma. 16S rRNA sequencing was used to examine relationships between eosinophil counts and the sputum microbiome. A post hoc analysis of the PROMIS (Inhaled Promixin in the Treatment of Non-Cystic Fibrosis Bronchiectasis) phase 2 trial was used to examine the impact of blood eosinophil counts on exacerbations in patients with Pseudomonas aeruginosa infection. Measurements and Main Results: A relationship between sputum and blood eosinophil counts was demonstrated in two cohorts. In analysis of 1,007 patients from five countries, 22.6% of patients had blood eosinophil counts of ⩾300 cells/μl. Counts of <100 cells/μl were associated with higher bronchiectasis severity and increased mortality. There was no clear relationship with exacerbations. Blood eosinophil counts of ⩾300 cells/μl were associated with both Streptococcus- and Pseudomonas-dominated microbiome profiles. To investigate the relationship of eosinophil counts with exacerbations after controlling for the confounding effects of infection, 144 patients were studied in a clinical trial after treatment with antipseudomonal antibiotics. Compared with patients with blood eosinophil counts of <100 cells/μl (reference), elevated eosinophil counts of 100-299 cells/μl (hazard ratio, 2.38; 95% confidence interval, 1.33-4.25; P = 0.003) and ⩾300 cells/μl (hazard ratio, 3.99; 95% confidence interval, 2.20-7.85; P < 0.0001) were associated with shorter time to exacerbation. Conclusions: Eosinophilic bronchiectasis affects approximately 20% of patients. After accounting for infection status, raised blood eosinophil counts are associated with shortened time to exacerbation.

Factors Influencing the Stability of Blood Eosinophils Counts in Chronic Obstructive Pulmonary Disease Patients

Blood eosinophil (EOS) has recently been recognized as a biomarker for chronic obstructive pulmonary disease (COPD) patients. However, few studies have concentrated on the stability of blood eosinophil counts (BEC), and those studies have produced varying results. With further research, we have found minor drawbacks and vulnerabilities that lead to the variability of the results. This paper enumerates several areas of relevant research with varying conclusions to further investigate the stability of BEC in COPD patients.

Spanish COPD Guidelines (GesEPOC) 2021: Updated Pharmacological treatment of stable COPD

The Spanish COPD Guidelines (GesEPOC) were first published in 2012, and since then have undergone a series of updates incorporating new evidence on the diagnosis and treatment of COPD. GesEPOC was drawn up in partnership with scientific societies involved in the treatment of COPD and the Spanish Patients' Forum. Their recommendations are based on an evaluation of the evidence using GRADE methodology, and a narrative description of the evidence in areas in which GRADE cannot be applied. In this article, we summarize the recommendations on the pharmacological treatment of stable COPD based on 9 PICO questions. COPD treatment is a 4-step process: 1) diagnosis, 2) determination of the risk level, 3) initial and subsequent inhaled therapy, and 4) identification and management of treatable traits. For the selection of inhaled therapy, high-risk patients are divided into 3 phenotypes: non-exacerbator, eosinophilic exacerbator, and non-eosinophilic exacerbator. Some treatable traits are general and should be investigated in all patients, such as smoking or inhalation technique, while others affect severe patients in particular, such as chronic hypoxemia and chronic bronchial infection. COPD treatment is based on long-acting bronchodilators with single agents or in combination, depending on the patient's risk level. Eosinophilic exacerbators must receive inhaled corticosteroids, while non-eosinophilic exacerbators require a more detailed evaluation to choose the best therapeutic option. The new GesEPOC also includes recommendations on the withdrawal of inhaled corticosteroids and on indications for alpha-1 antitrypsin treatment. GesEPOC offers a more individualized approach to COPD treatment tailored according to the clinical characteristics of patients and their level of complexity.

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.

Variability of blood eosinophil count and prognosis of COPD exacerbations

BACKGROUND

Eosinophils in peripheral blood are one of the emerging biomarkers in chronic obstructive pulmonary disease (COPD) patients. However, when analysing the relationship between peripheral eosinophilia and COPD prognosis, highly variable results are obtained. The aim of our study is to describe the serum eosinophilia levels in COPD patients and to analyse their relationship to prognosis following hospital admission.

METHODS

A prospective observational study was conducted from 1 October 2016 to 1 October 2018 in the following Spanish centres: Salnés County Hospital in Vilagarcía de Arousa, Arquitecto Marcide Hospital in Ferrol and the University Hospital Complex in Santiago de Compostela. The patients were classified using three cut-off points of blood eosinophil count (BEC): 150 cells/µL, 300 cells/µL, and 400 cells/µL; in addition, the peripheral BEC was analysed on admission.

RESULTS

615 patients were included in the study, 86.2% male, mean age 73.9 years, and mean FEV1 52.7%. The mean stay was 8.4 days, and 6% of all patients were readmitted early. No significant relationship was observed between the BEC, neither in the stable phase nor in the acute phase, and hospital stay, readmissions, deaths during admission, the need for intensive care, or the condition of frequent exacerbator.

CONCLUSION

The results of our study do not seem to support the usefulness of BEC as a COPD biomarker.KEY MESSAGESThere is evidence that BEC participates in pathophysiological mechanisms of the COPD.BEC may be useful as a biomarker in COPD for aspects such as the optimization of treatments.We did not find any relationship between BEC levels and prognosis following hospital admission for AECOPD.

Stability of blood eosinophils in acute exacerbation of chronic obstructive pulmonary disease and its relationship to clinical outcomes: a prospective cohort study

BACKGROUND

The clinical value of blood eosinophils and their stability in chronic obstructive pulmonary disease (COPD) remains controversial. There are limited studies on association between the stability of blood eosinophils in acute exacerbation of COPD (AECOPD) and clinical outcomes. This study aimed to evaluate the stability of blood eosinophils in hospitalized AECOPD and its relationship to clinical outcomes.

METHODS

This prospective observational study recruited patients hospitalized with AECOPD from November 2016 to July 2020. The eligible patients were divided into four groups according to their blood eosinophil counts at admission and discharge: persistently < 300 cells/μl (LL), < 300 cells/μl at admission but ≥ 300 cells/µl at discharge (LH), ≥ 300 cells/μl at admission but < 300 cells/µl at discharge (HL), and persistently ≥ 300 cells/μl (HH). Cox hazard analyses were used to study the association between eosinophil changes and exacerbations or mortality.

RESULTS

In 530 patients included, 90 (17.0%) had a high blood eosinophil count (BEC) ≥ 300 cells/µl at admission but 32 (35.6%) of them showed a decreased BEC at discharge. The proportions and distribution for group LL, LH, HL, and HH were 381 (71.9%), 59 (11.1%), 32 (6.0%), and 58 (10.9%), respectively. During hospitalization, the LH group had a higher C-reactive protein level, higher rate of intensive care unit (ICU) admission, and higher total cost. The length of hospital stay of the LH group was longer compared with group LL, HL, or HH (P = 0.002, 0.017, and 0.001, respectively). During a follow-up of 12 months, the HH group was associated with a higher risk of moderate-to-severe exacerbations compared to the LL group (hazard ratio 2.00, 95% confidence interval 1.30-3.08, P = 0.002). Eosinophil changes had no significant association with mortality at 12 months. Sensitivity analyses in patients without asthma and without use of systemic corticosteroids prior to admission did not alter the results.

CONCLUSIONS

More attention should be paid to the LH group when evaluating the short-term prognosis of AECOPD. A persistently high BEC was a risk factor for long-term exacerbations. Eosinophil changes during hospitalization could help to predict outcomes.

From Biomarkers to Novel Therapeutic Approaches in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a heterogeneous and complex disorder. In this review, we provided a comprehensive overview of biomarkers involved in COPD, and potential novel biological therapies that may provide additional therapeutic options for COPD. The complex characteristics of COPD have made the recommendation of a generalized therapy challenging, suggesting that a tailored, personalized strategy may lead to better outcomes. Existing and unmet needs for COPD treatment support the continued development of biological therapies, including additional investigations into the potential clinical applications of this approach.

Eosinophilic endotype of chronic obstructive pulmonary disease: similarities and differences from asthma

Approximately 25% to 40% of patients with chronic obstructive pulmonary disease (COPD) have the eosinophilic endotype. It is important to identify this group accurately because they are more symptomatic and are at increased risk for exacerbations and accelerated decline in forced expiratory volume in the 1st second. Importantly, this endotype is a marker of treat ment responsiveness to inhaled corticosteroid (ICS), resulting in decreased mortality risk. In this review, we highlight differences in the biology of eosinophils in COPD compared to asthma and the different definitions of the COPD eosinophilic endotype based on sputum and blood eosinophil count (BEC) with the corresponding limitations. Although BEC is useful as a biomarker for eosinophilic COPD endotype, optimal BEC cut-offs can be combined with clinical characteristics to improve its sensitivity and specificity. A targeted approach comprising airway eosinophilia and appropriate clinical and physiological features may improve identification of subgroups of patients who would benefit from biologic therapy or early use of ICS for disease modification.

The Role of Blood Eosinophils in the Management of COPD: An Attempt to Answer the Important Clinical Questions

Blood eosinophils have been proposed as a surrogate biomarker of airway eosinophilia that can be used for treatment decisions in patients with COPD, mainly for the identification of candidates for the initiation or withdrawal of therapy with inhaled corticosteroids, as well as for the identification of patients at future risk of exacerbations. In this manuscript we review the recent literature on blood eosinophils in the management of patients with COPD, in an attempt to answer the major questions that are relevant for the practicing clinician. A growing body of evidence suggests that eosinophilic COPD may constitute a separate phenotype of the disease with distinct clinical features and blood eosinophils may represent a potential candidate surrogate marker for specific COPD patients. Several points still need to be clarified, including the role of eosinophils for the identification of candidates for future COPD therapies, yet blood eosinophils plausibly represent the most dependable and promising biomarker for the precision management of COPD today.

Neutrophil-to-lymphocyte ratio, blood eosinophils and COPD exacerbations: a cohort study

Background

Blood neutrophil-to-lymphocyte ratio (NLR) and blood eosinophils (B-Eos) are emerging biomarkers in COPD. This study examined whether they could predict acute exacerbations of COPD (AECOPDs), and determined their longitudinal stability.

Methods

In this closed cohort study, Swedish subjects with spirometry-verified COPD attended three yearly visits in a stable phase of the disease. Blood cell counts, spirometry and questionnaire-assessed AECOPD-history (worsening of COPD leading to an unscheduled visit and/or use of antibiotics and/or oral corticosteroids) were collected at each visit.

Results

Of 466 included subjects 57% were female. Baseline mean±sd forced expiratory volume in 1 s was 58±17% predicted. High NLR (≥3.0) was more common in subjects with previous AECOPDs than in those without (33.5% versus 20.4%, p=0.002). In two-level mixed-effects logistic regression models adjusted for confounders, NLR as a continuous variable (OR 1.20, 95% CI 1.04–1.38) and B-Eos ≥300 cells·µL⁻¹ (OR 1.54, 95% CI 1.06–2.24) were associated with future AECOPDs. In 386 subjects with blood cell data available at all three visits, the intraclass correlation coefficient for NLR was 0.61 (95% CI 0.56–0.66) and for B-Eos 0.69 (95% CI 0.64–0.73). NLR was persistently ≥3.0 in 10.6% and B-Eos was persistently ≥300 cells·µL⁻¹ in 15.3%.

Conclusions

Stable phase NLR and B-Eos were associated with future AECOPDs. NLR on its own is probably not useful to predict AECOPDs but might be included in a risk scoring index. A minority of subjects with COPD had persistently elevated stable-phase NLR or B-Eos, and the biomarkers showed fair longitudinal reliability.

Neutrophil-to-lymphocyte ratio and blood eosinophils in stable-phase COPD are associated with future exacerbations and show fair longitudinal reliabilityhttps://bit.ly/3CAS1jY

Lysophosphatidic acid species are associated with exacerbation in chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) exacerbations are heterogenous and profoundly impact the disease trajectory. Bioactive lipid lysophosphatidic acid (LPA) has been implicated in airway inflammation but the significance of LPA in COPD exacerbation is not known. The aim of the study was to investigate the utility of serum LPA species (LPA16:0, 18:0, 18:1, 18:2, 20:4) as biomarkers of COPD exacerbation.

PATIENTS AND METHODS

LPA species were measured in the baseline placebo sera of a COPD randomized controlled trial. Tertile levels of each LPA were used to assign patients into biomarker high, medium, and low subgroups. Exacerbation rate and risk were compared among the LPA subgroups.

RESULTS

The levels of LPA species were intercorrelated (rho 0.29-0.91). Patients with low and medium levels of LPA (LPA16:0, 20:4) had significantly higher exacerbation rate compared to the respective LPA-high patients [estimated rate per patient per year (95% CI)]: LPA16:0-low = 1.2 (0.8-1.9) (p = 0.019), LPA16:0-medium = 1.3 (0.8-2.0) (p = 0.013), LPA16:0-high = 0.5 (0.2-0.9); LPA20:4-low = 1.4 (0.9-2.1) (p = 0.0033), LPA20:4-medium = 1.2 (0.8-1.8) (p = 0.0089), LPA20:4-high = 0.4 (0.2-0.8). These patients also had earlier time to first exacerbation (hazard ratio (95% CI): LPA16:0-low = 2.6 (1.1-6.0) (p = 0.028), LPA16:0-medium = 2.7 (1.2-6.3) (p = 0.020); LPA20.4-low = 2.8 (1.2-6.6) (p = 0.017), LPA20:4-medium = 2.7 (1.2-6.4) (p = 0.021). Accordingly, these patients had a significant increased exacerbation risk compared to the respective LPA-high subgroups [odd ratio (95% CI)]: LPA16:0-low = 3.1 (1.1-8.8) (p = 0.030), LPA16:0-medium = 3.0 (1.1-8.3) (p = 0.031); LPA20:4-low = 3.8 (1.3-10.9) (p = 0.012), LPA20:4-medium = 3.3 (1.2-9.5) (p = 0.025). For the other LPA species (LPA18:0, 18:1, 18:2), the results were mixed; patients with low and medium levels of LPA18:0 and 18:2 had increased exacerbation rate, but only LPA18:0-low patients had significant increase in exacerbation risk and earlier time to first exacerbation compared to the LPA18:0-high subgroup.

CONCLUSIONS

The study provided evidence of association between systemic LPA levels and exacerbation in COPD. Patients with low and medium levels of specific LPA species (LPA16:0, 20:4) had increased exacerbation rate, risk, and earlier time to first exacerbation. These non-invasive biomarkers may aid in identifying high risk patients with dysregulated LPA pathway to inform risk management and drug development.

Characterization Associated with the Frequent Severe Exacerbator Phenotype in COPD Patients

Background

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disease with exacerbations causing hospitalizations, morbidity, and mortality. COPD exacerbation causes a substantial health impact, and its subtypes might differ in prognosis and treatment response.

Methods

This study evaluated the factors of COPD exacerbations and explored the probabilities of frequent severe COPD exacerbations. Categorical and continuous variables between groups were compared. The hazard ratio (HR) and the probability of no hospital readmission were also estimated.

Results

A total of 617 COPD patients were enrolled and comprised the frequent exacerbator (N = 226) and the non-frequent exacerbator (N = 391) groups. The frequent exacerbator group significantly displayed a higher eosinophil count (EC; p=0.004), a higher percentage of the frequent severe acute exacerbation history before the index hospitalization (IH; p < 0.001), a lower FEV1 value (p=0.001), and a higher triple combination inhaler prior and following the IH (p < 0.001 and p=0.002) than the non-frequent exacerbator one. Increasing age (aOR of 1.02), higher EC (aOR of 1.09), and lower FEV1 value (aOR of 0.72) were significantly associated with an increased hospital readmission risk. The readmission rate and risk were higher in patients with a history of frequent severe acute exacerbation (aHR of 3.38) than those without severe acute exacerbation. Cases treated with the triple combination inhaler before the IH had a higher readmission rate and risk than non-users.

Conclusion

Patients with EC ≥2%, FEV1 <50%, or frequent severe acute exacerbation history before the IH have a higher risk of being diagnosed with a frequent exacerbator phenotype. Besides, higher age, triple combination inhaler before the IH, and smoking might be independently correlated with the frequent readmission risk within 1-year post-exacerbation. A better comprehension of the COPD exacerbation mechanism may further identify the best course of preventative strategy and lead to novel interventions.

Clinical Predictors of High Blood Eosinophils in Chronic Obstructive Pulmonary Disease

Purpose

Elevated blood eosinophils have been implicated in chronic obstructive pulmonary disease (COPD) progression and exacerbation. We aim to investigate clinical predictors of high blood eosinophils in a Chinese COPD cohort.

Patients and Methods

We conducted a retrospective cohort study in Sichuan province, a Southwest province with high prevalence of COPD in China. All patients in this cohort were extracted from the Chinese Pulmonary Health study, a large cross-sectional study on COPD epidemiology in China. Demographics, personal and family history, living condition, spirometry and blood eosinophil counts were obtained. Univariate and multiple linear regression analyses were performed to determine predictors of high blood eosinophils.

Results

A total of 375 COPD patients were included in this cohort. The median absolute blood eosinophil count was 138.8 cells/μL, and the prevalence of COPD with high blood eosinophils was 66.7% and 14.7% when using the thresholds of 100 cells/μL and 300 cells/μL, respectively. Univariate analyses indicated that male gender, lower body mass index, high-density lipoprotein (HDL), lower family income, raising pets and biomass use were significantly associated with high blood eosinophils (p < 0.05). Multiple linear regression model further revealed male gender (unstandardized coefficient (B)=66.125, 95% confidence intervals (CI) 16.350 to 115.900, p=0.009), age (B=2.819, 95% CI 0.639 to 5.000, p=0.012) predicted high blood eosinophil level, whereas HDL (B=−64.682, 95% CI −123.451 to −5.914, p=0.031) was a negative predictor for high blood eosinophils.

Conclusion

This retrospective cohort study suggests male gender, oldness and lower HDL could be clinical predictors of high blood eosinophils in Chinese COPD patients.

Phenotypic Clustering in Non-Cystic Fibrosis Bronchiectasis Patients: The Role of Eosinophils in Disease Severity

Whether high blood eosinophil counts may define a better phenotype in bronchiectasis patients, as shown in chronic obstructive pulmonary disease (COPD), remains to be investigated. Differential phenotypic characteristics according to eosinophil counts were assessed using a biostatistical approach in a large cohort study from the Spanish Online Bronchiectasis Registry (RIBRON). The 906 patients who met the inclusion criteria were clustered into two groups on the basis of their eosinophil levels. The potential differences according to the bronchiectasis severity index (BSI) score between two groups (Mann–Whitney U test and eosinophil count threshold: 100 cells/µL) showed the most balanced cluster sizes: above-threshold and below-threshold groups. Patients above the threshold exhibited significantly better clinical outcomes, lung function, and nutritional status, while showing lower systemic inflammation levels. The proportion of patients with mild disease was higher in the above-threshold group, while the below-threshold patients were more severe. Two distinct clinical phenotypes of stable patients with non-cystic fibrosis (CF) bronchiectasis of a wide range of disease severity were established on the basis of blood eosinophil counts using a biostatistical approach. Patients classified within the above-threshold cluster were those exhibiting a mild disease, significantly better clinical outcomes, lung function, and nutritional status while showing lower systemic inflammatory levels. These results will contribute to better characterizing bronchiectasis patients into phenotypic profiles with their clinical implications.

Area under flow-volume loop may predict severe exacerbation in COPD patients with high grade of dyspnea

OBJECTIVE

Exacerbations in patients with COPD may still be unpredictable, although the general risk factors have been well defined. We aimed to determine the role of a novel parameter, area under flow-volume loop, in predicting severe exacerbations.

METHODS

In this single-centre retrospective cohort study, 81 COPD patients over 40 years of age with high grade of dyspnea (having a CAT score of ≥10) and a history of ≥1 moderate exacerbation in the previous year were included. Area under flow-volume curve (AreaFE%) was obtained from pulmonary function test graph and calculated from Matlab programme. Univariate and multivariate logistic regression analyses were performed to determine independent risk factors of the severe exacerbation.

RESULTS

Patients with severe exacerbation (n = 70, 86.4 %) were older. They had lower FEV1%, FVC%, 6MWD, AreaFE% and higher CAT score than patients without exacerbation. After performing multivariate analysis, high CAT score and low AreaFE% value were found to be independent risk factors for severe exacerbation (OR: 1.12, 95 % CI: 1.065-1.724; p = 0.01 and OR: 1.18, 95 % CI: 0.732-0.974; p = 0.02).

CONCLUSIONS

We found that a low AreaFE% value was an independent risk factor in addition to a high CAT score and these both have an excellent discriminative ability in predicting the risk of severe exacerbation.

Blood eosinophil count-guided corticosteroid therapy and as a prognostic biomarker of exacerbations of chronic obstructive pulmonary disease: a systematic review and meta-analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is characterized by persistent respiratory symptoms and dyspnea, as well as an increase in the number of leukocytes in the airways, lungs, and pulmonary vessels. A 'One size fits all' approach to COPD patients with different clinical features may be considered outdated. The following are the two major objectives of this meta-analysis: the first is to determine if blood eosinophil counts (BEC) can serve as a prognostic biomarker of COPD outcomes, and the second is to determine which level of BEC is effective for inhaled corticosteroid (ICS) treatment.

METHODS

We searched articles published before 15 May 2021 in the following four electronic databases: Web of Science, Cochrane Library, EMBASE, and PubMed.

RESULTS

A total of 42 studies, comprising a sampling of 188,710 subjects, were summarized and compared in this meta-analysis. The rate ratio (RR) of exacerbations of COPD (ECOPD) between ICS and non-ICS treatment was statistically significant for the COPD patients with a baseline BEC ⩾ 2% or ⩾ 200 cells/μl, RR = 0.82 (0.73, 0.93) or 0.79 (0.70, 0.89) respectively, while the RR of ECOPD between ICS and non-ICS treatment was statistically insignificant for the COPD patients with baseline BEC < 2% or <200 cells/μl, RR = 0.97 (0.87, 1.08) or 0.97 (0.86, 1.08), suggested that ICS therapy was beneficial to the improvement of ECOPD in patients with a baseline BEC ⩾ 2% or BEC ⩾ 200 cells/μl.

CONCLUSION

Our research shows that a BEC ⩾ 200 cells/μl or ⩾2% is likely to become the cutoff value of ICS treatment for ECOPD. Moreover, we believe that the baseline BEC can be used as a biomarker for predicting ECOPD. The stability of BEC requires special attention.

The sputum transcriptome better predicts COPD exacerbations after the withdrawal of inhaled corticosteroids than sputum eosinophils

Introduction

Continuing inhaled corticosteroid (ICS) use does not benefit all patients with COPD, yet it is difficult to determine which patients may safely sustain ICS withdrawal. Although eosinophil levels can facilitate this decision, better biomarkers could improve personalised treatment decisions.

Methods

We performed transcriptional profiling of sputum to explore the molecular biology and compared the predictive value of an unbiased gene signature versus sputum eosinophils for exacerbations after ICS withdrawal in COPD patients. RNA-sequencing data of induced sputum samples from 43 COPD patients were associated with the time to exacerbation after ICS withdrawal. Expression profiles of differentially expressed genes were summarised to create gene signatures. In addition, we built a Bayesian network model to determine coregulatory networks related to the onset of COPD exacerbations after ICS withdrawal.

Results

In multivariate analyses, we identified a gene signature (LGALS12, ALOX15, CLC, IL1RL1, CD24, EMR4P) associated with the time to first exacerbation after ICS withdrawal. The addition of this gene signature to a multiple Cox regression model explained more variance of time to exacerbations compared to a model using sputum eosinophils. The gene signature correlated with sputum eosinophil as well as macrophage cell counts. The Bayesian network model identified three coregulatory gene networks as well as sex to be related to an early versus late/nonexacerbation phenotype.

Conclusion

We identified a sputum gene expression signature that exhibited a higher predictive value for predicting COPD exacerbations after ICS withdrawal than sputum eosinophilia. Future studies should investigate the utility of this signature, which might enhance personalised ICS treatment in COPD patients.

Sputum gene expression may have utility in biomarker development for identifying subjects who are at higher risk of exacerbation after ICS withdrawalhttps://bit.ly/3gYl2OL

Blood Eosinophils and Clinical Outcomes in Patients With Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Propensity Score Matching Analysis of Real-World Data in China

Background and Objective: Elevated eosinophils in chronic obstructive pulmonary disease (COPD) are recognized as a biomarker to guide inhaled corticosteroids use, but the value of blood eosinophils in hospitalized exacerbations of COPD remains controversial. This study aimed to evaluate the accuracy of eosinophils in predicting clinical outcomes in acute exacerbation of COPD (AECOPD).

Methods: We analyzed data from the acute exacerbation of chronic obstructive pulmonary disease inpatient registry (ACURE) study, which is an ongoing nationwide multicenter, observational real-world study in patients admitted for AECOPD. Data collected between January 2018 and December 2019 in 163 centers were first reviewed. The eligible patients were divided into eosinophilic and non-eosinophilic groups, according to blood eosinophil with 2% of the total leukocyte count as the threshold. Propensity score (PS) matching was performed to adjust for confounders.

Results: A total of 1,566 patients (median age: 69 years; 80.3% male) were included and 42.7% had an eosinophilic AECOPD. Eosinophil count <2% was associated with the development of respiratory failure and pneumonia. After PS matching, 650 pairs in overall patients, 468 pairs in patients with smoking history and 177 pairs in patients without smoking were selected, respectively. Only in patients with smoking history, the non-eosinophilic AECOPD was associated with longer median hospital stays (9 vs. 8 days, P = 0.034), higher dosage of corticosteroid use, higher economic burden of hospitalization, and poorer response to corticosteroid therapy compared to the eosinophilic AECOPD. No significant difference was found in patients without smoking. Eosinophil levels had no relationship with the change of COPD Assessment Test scores and readmissions or death after 30 days.

Conclusion: Elevated eosinophils were associated with better short-term outcomes only in patients with a smoking history. Eosinophil levels cannot be confidently used as a predictor alone for estimating prognosis.

Eicosanoids and Eosinophilic Inflammation of Airways in Stable COPD

Purpose

Lipid mediators, particularly eicosanoids, are associated with airway inflammation, especially with the eosinophilic influx. This study aimed to measure lipid mediators and cells in induced sputum, that could possibly reflect the inflammatory process in the bronchial tree of COPD subjects.

Patients and Methods

Eighty patients diagnosed with COPD and 37 healthy controls participated in the study. Induced sputum samples were ascertained for differential cell count and induced sputum supernatant concentrations of selected eicosanoids by the means of gas chromatography/mass spectrometry and high-performance liquid chromatography/tandem mass spectrometry.

Results

Increased sputum eosinophilia was associated with higher concentrations of selected proinflammatory eicosanoids. In COPD subjects prostaglandin D₂ and 11-dehydro-thromboxane B₂ correlated negatively with airway obstruction measured by FEV₁ and FEV₁/FVC values. COPD subjects with disease exacerbations during past 12 months had significantly higher concentrations of prostaglandin D₂, 12-oxo-eicosatetraenoic acid and 5-oxo-eicosatetraenoic acid.

Conclusion

Stable COPD is often associated with eosinophil influx in the lower airways and elevated concentrations of eicosanoids that is reflected by some disease characteristics.

Blood eosinophils as predictor of outcomes in patients hospitalized for COPD exacerbations: a prospective observational study

PURPOSE

In the present prospective multicentre observational study, we evaluated the potential role of blood eosinophils on the outcomes of patients hospitalized for COPD exacerbations.

MATERIAL AND METHODS

Consecutive patients >40 years with a previous COPD diagnosis were recruited. Blood eosinophils were measured on admission prior to the initiation of treatment and were evaluated in three groups (<50, 50-149 and ≥150 cells/μL). Patients received standard care and were followed up for a year.

RESULTS

A total of 388 patients were included (83.5% male, mean age 72 years). Patients with higher blood eosinophils had less dyspnoea (Borg scale), lower C-reactive protein (CRP) and higher PaO₂/FiO₂ (partial pressure for oxygen/fraction of inhaled oxygen), and were discharged earlier (median 11 vs. 9 vs. 5 days for patients with <50, 50-149 and ≥150 cells/μL, respectively). Patients with <50 cells/μL presented higher 30-day and 1-year mortality, whereas there were no differences in moderate/severe COPD exacerbations between the three groups. In a post hoc analysis, treatment with inhaled corticosteroids as per physicians' decision was associated with better exacerbation prevention during follow-up in patients with ≥150 cells/μL.

CONCLUSIONS

Higher blood eosinophils were associated with better outcomes in hospitalized COPD patients, further supporting their use as a prognostic biomarker.

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.

High Blood Eosinophil and YKL-40 Levels, as Well as Low CXCL9 Levels, are Associated with Increased Readmission in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Background

Readmission after hospital discharge is common among patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Predictive biomarkers of readmission would facilitate stratification strategies and individualized prognosis. Therefore, this study aimed to investigate the utility of type 2 biomarkers (eosinophils, periostin, and YKL-40) and a type 1 biomarker (CXCL9) in predicting readmission events in patients with AECOPD.

Methods

This is a prospective observational study design. Blood levels of eosinophils, periostin, YKL-40, and CXCL9 were measured at admission. The clinical outcomes were 12-month COPD-related readmission, time to COPD-related readmission, and number of 12-month COPD-related readmissions. These outcomes were analyzed using logistic and Cox regression models and Spearman's rank test.

Results

A total of 123 patients were included, of whom 51 had experienced at least one readmission for AECOPD. High levels of eosinophils (≥200 cells/μL or 2% of the total white blood cell count, adjusted odds ratio [aOR] =3.138, P=0.009) and YKL-40 (≥14.5 ng/mL, aOR =2.840, P=0.015), as well as low CXCL9 levels (≤30.1 ng/mL, aOR =2.551, P=0.028), were associated with an increased COPD-related readmission. The highest relative readmission rate was observed in patients with both high eosinophil and YKL-40 levels. Moreover, high eosinophil and YKL-40 levels were associated with a shorter time to first COPD-related readmission and an increased number of 12-month COPD-related readmissions.

Conclusion

High blood eosinophil and YKL-40 levels, as well as low CXCL9 levels, have predictive utility for the 12-month COPD-related readmission rate. Using eosinophils and YKL-40 together allows more precise identification of patients at high risk of COPD-related readmission.

The association between eosinophilic exacerbation and eosinophilic levels in stable COPD

Background

Blood eosinophil count may predict treatment response in patients with chronic obstructive pulmonary disease (COPD) during acute exacerbations (AE). However, the ability and thresholds of blood eosinophil counts in stable status to predict eosinophilic AECOPD have not been completely investigated.

Methods

This was a retrospective multicenter study performed January 2010 to December 2014. COPD subjects hospitalized with exacerbations, were included. Blood samples were obtained at the time of AE and stable disease at outpatient clinic before or after admission. We identified a blood eosinophil count cut-off point at stable COPD, either taken as a percentage or as absolute value, for identification of eosinophilic exacerbation.

Results

There was significant positive correlation of eosinophil counts between stable COPD and AECOPD. The best cut-off value of blood eosinophil count in stable status for the prediction of eosinophilic COPD exacerbation based on blood eosinophil count ≥ 2% was 300 cells/µL (area under the ROC curve [AUC] 0.614, P = 0.001, 39% sensitivity, 83.8% specificity). When the eosinophilic COPD exacerbation was based on blood eosinophil count ≥ 300 cells/µL, the best cut-off value of blood eosinophil count in stable status for the prediction of eosinophilic COPD exacerbation was also 300 cells/uL (AUC 0.634, P = 0.046, 45.8% sensitivity, 80.9% specificity).

Conclusions

We demonstrated association between blood eosinophil counts at stable COPD and those with AECOPD. The thresholds of blood counts at stable COPD to predict eosinophilic exacerbations was 300 cells/µL. Further and prospective studies in other populations should validate our results.

Is Blood Eosinophil Count a Biomarker for Chronic Obstructive Pulmonary Disease in a Real-World Clinical Setting? Predictive Property and Longitudinal Stability in Japanese Patients

The authors examined predictive properties and the longitudinal stability of blood eosinophil count (BEC) or three strata (<100 cells/mm³, 100-299 cells/mm³ and ≥300 cells/mm³) in patients with chronic obstructive pulmonary disease (COPD) for up to six and a half years as part of a hospital-based cohort study. Of the 135 patients enrolled, 21 (15.6%) were confirmed to have died during the follow-up period. Episodes of acute exacerbation of COPD (AECOPD) were identified in 74 out of 130 available patients (56.9%), and admission due to AECOPD in 35 out of 132 (26.5%). Univariate Cox proportional hazards analyses revealed that almost all the age, forced expiratory volume in 1 s (FEV₁) and health status measures using St. George's Respiratory Questionnaire (SGRQ) Total and COPD Assessment Test (CAT) Score were significantly related to these types of events, but the relationship between age and AECOPD did not reach statistical significance (p = 0.05). Neither BEC nor the three different groups stratified by BEC were significant predictors of any subsequent events. There were no significant differences in the BEC between Visits 1-3 (p = 0.127, Friedman test). The ICC value was 0.755 using log-transformed data, indicating excellent repeatability. In the case of assigning to strata, Fleiss' kappa was calculated to be 0.464, indicating moderate agreement. The predictive properties of BEC may be limited in a real-world Japanese clinical setting. Attention must be paid to the fact that the longitudinal stability of the three strata is regarded as moderate.

COPD patients prescribed inhaled corticosteroid in primary care: time for re-assessment based on exacerbation rate and blood eosinophils?

BACKGROUND AND OBJECTIVE

Inhaled corticosteroid (ICS) therapy for COPD should be guided by exacerbations and blood-eosinophils according to the GOLD 2020 strategy document. In the present study, we applied these recent recommendations in a large cohort of COPD patients recruited from general practice.

METHODS

The participating general practitioners (n = 144) recruited patients with a diagnosis of COPD currently prescribed ICS and reported data on exacerbation history and blood-eosinophils. Clinical variables were compared using two-sample t-tests.

RESULTS

The study cohort comprised 1,567 COPD patients (44% males and mean age 72 years). In the past 12 months, 849 (54%) of the COPD patients currently prescribed ICS had no exacerbation, whereas 383 (24%) and 328 (21%) patients, respectively, had a history of one exacerbation and two or more exacerbations. Compared to patients with one or no exacerbation, patients with ≥ 2 exacerbations (21%) per year reported more dyspnea (p < 0.001) and had higher degree of airflow obstruction (p < 0.001). Among patients with no and at least one exacerbation within the preceding 12 months, 30% and 26%, respectively, had a blood-eosinophil count ≥ 0.3 × 10⁹/L. In patients with two or more exacerbations within the last 12 months, 77% had a blood-eosinophil count of ≥ 0.1 × 10⁹/L. Furthermore, 166 patients (11%) had at least one hospital admission due to COPD exacerbation, and a blood-eosinophil count of ≥ 0.1 × 10⁹/L.

CONCLUSION

This study of a large cohort of COPD patients currently prescribed inhaled corticosteroids suggests the need for re-evaluating the management strategy to increase benefit and reduce adverse effects of ICS treatment in COPD patients managed in primary care.

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.