Eosinophilia and clinical outcome of chronic obstructive pulmonary disease: a meta-analysis

Serum Amyloid A in Stable Patients with Chronic Obstructive Pulmonary Disease Does Not Reflect the Clinical Course of the Disease

Serum amyloid A (SAA) is a good systemic marker of the exacerbations of chronic obstructive pulmonary disease (COPD), but the significance of SAA in stable patients with COPD has not been widely investigated. We aimed to evaluate the SAA level in peripheral blood from stable patients with COPD and to search for correlations between SAA and other inflammatory markers and clinical characteristics of the disease. Serum SAA, IL-6, IL-8, TNF-alpha, basic blood investigations, pulmonary function testing and a 6-min walk test were performed. The correlations between SAA and other inflammatory markers, functional performance and the number of disease exacerbations were evaluated. A total of 100 consecutive patients with COPD were analyzed. No correlations between SAA and inflammatory markers as well as pulmonary function were found. Hierarchical clustering identified two clusters incorporating SAA: one comprised SAA, PaO₂ and FEV₁ and the second was formed of SAA and nine other disease markers. The SAA level was higher in patients with blood eosinophils < 2% when compared to those with blood eosinophils ≥ 2% (41.8 (19.5-69.7) ng/mL vs. 18.9 (1.0-54.5) ng/mL, respectively, p = 0.04). We conclude that, in combination with other important disease features, SAA may be useful for patient evaluation in stable COPD.

Association of Upon-Diagnosis Blood Eosinophilic Count with Frequency and Severity of Annual Exacerbation in Chronic Obstructive Pulmonary Disease: A Prospective Longitudinal Analysis

Introduction

There is a controversy regarding the relationship between blood eosinophil count and COPD exacerbation. We aimed to determine whether peripheral eosinophils upon COPD diagnosis could affect the frequency and severity of annual acute exacerbation of COPD (AECOPD).

Methods

This prospective study was conducted on 973 newly diagnosed COPD patients who were under 1-year follow-up in a pulmonology center in Iran. The Cox proportional model, polynomial regression, and receiver operator characteristic curves were conducted to evaluate the impact of the eosinophil levels on AECOPD. A linear regression model was conducted to evaluate the continuous association of eosinophilic count with AECOPDs.

Results

Patients with eosinophil >200 cells/microliter were higher pack-year smokers with more pulmonary hypertension prevalence compared to COPD patients with <200 cells/microliter. There was a positive correlation between the eosinophilic count and the frequency of AECOPDs. Eosinophil >900 cells/microliter and eosinophil >600 cells/microliter had a sensitivity of 71.1% and 64.3%, respectively, in predicting the occurrence of more than one AECOPD. Eosinophilic count cutoff of 800 cells/microliter had the highest Youden index with sensitivity and specificity of 80.2% and 76.6%, respectively, for incident AECOPD in newly diagnosed patients. Using a linear model, increasing 180 cells/microliter in serum eosinophils was associated with further exacerbation. Evaluating gender, BMI, smoking pack-year, FEV1/FVC, CAT score, GOLD score, pulmonary hypertension, annual influenza, pneumococcal vaccinations, leukocytosis, and blood eosinophils, only blood eosinophils (hazard ratio (HR) = 1.44; 95% confidence interval = 1.33-2.15; p value = 0.03) and GOLD score (HR = 1.19; 95% CI = 1.30-1.52; p value = 0.03) were found as independent risk factors of AECOPD >3 episodes/year. Requirement for ICU admission, invasive ventilation, and mortality rate due to AECOPDs was similar between eosinophilic and noneosinophilic groups.

Conclusion

Eosinophilia upon COPD diagnosis is a factor of recurrent AECOPDs. To reduce the risk of AECOPDs and the burden of disease, clinicians may consider inhaler corticosteroids and domiciliary oxygen with a lower threshold for eosinophilic-COPD patients regardless of their clinical status.

Impact of Acute Exacerbation and Its Phenotypes on the Clinical Outcomes of Chronic Obstructive Pulmonary Disease in Hospitalized Patients: A Cross-Sectional Study

Acute exacerbations of COPD (AECOPD) are clinically significant events having therapeutic and prognostic consequences. However, there is a lot of variation in its clinical manifestations described by phenotypes. The phenotypes of AECOPD were categorized in this study based on pathology and exposure. In our cross-sectional study, conducted between 1 January 2016 to 31 December 2020, the patients were categorized into six groups based on pathology: non-bacterial and non-eosinophilic; bacterial; eosinophilic; bacterial infection with eosinophilia; pneumonia; and bronchiectasis. Further, four groups were classified based on exposure to tobacco smoke (TS), biomass smoke (BMS), both, or no exposure. Cox proportional-hazards regression analyses were performed to assess hazard ratios, and Kaplan-Meier analysis was performed to assess survival, which was then compared using the log-rank test. The odds ratio (OR) and independent predictors of ward admission type and length of hospital stay were assessed using binomial logistic regression analyses. Of the 2236 subjects, 2194 were selected. The median age of the cohort was 67.0 (60.0 to 74.0) and 75.2% were males. Mortality rates were higher in females than in males (6.2% vs. 2.3%). AECOPD-B (bacterial infection) subjects [HR 95% CI 6.42 (3.06-13.46)], followed by AECOPD-P (pneumonia) subjects [HR (95% CI: 4.33 (2.01-9.30)], were at higher mortality risk and had a more extended hospital stay (6.0 (4.0 to 9.5) days; 6.0 (4.0 to 10.0). Subjects with TS and BMS-AECOPD [HR 95% CI 7.24 (1.53-34.29)], followed by BMS-AECOPD [HR 95% CI 5.28 (2.46-11.35)], had higher mortality risk. Different phenotypes have different impacts on AECOPD clinical outcomes. A better understanding of AECOPD phenotypes could contribute to developing an algorithm for the precise management of different phenotypes.

From COPD to Lung Cancer: Mechanisms Linking, Diagnosis, Treatment, and Prognosis

Many studies have proved that the pathogenesis of the chronic obstructive pulmonary disease (COPD) and lung cancer is related, and may cause and affect each other to a certain extent. In fact, the change of chronic airway obstruction will continue to have an impact on the screening, treatment, and prognosis of lung cancer.In this comprehensive review, we outlined the links and heterogeneity between COPD and lung cancer and finds that factors such as gene expression and genetic susceptibility, epigenetics, smoking, epithelial mesenchymal transformation (EMT), chronic inflammation, and oxidative stress injury may all play a role in the process. Although the relationship between these two diseases have been largely determined, the methods to prevent lung cancer in COPD patients are still limited. Early diagnosis is still the key to a better prognosis. Thus, it is necessary to establish more intuitive screening evaluation criteria and find suitable biomarkers for lung cancer screening in high-risk populations with COPD. Some studies have indicated that COPD may change the efficacy of anti-tumor therapy by affecting the response of lung cancer patients to immune checkpoint inhibitors (ICIs). And for lung cancer patients with COPD, the standardized management of COPD can improve the prognosis. The treatment of lung cancer patients with COPD is an individualized, comprehensive, and precise process. The development of new targets and new strategies of molecular targeted therapy may be the breakthrough for disease treatment in the future.

Biomarkers, Clinical Course, and Individual Needs in COPD Patients in Primary Care: The Study Protocol of the Stockholm COPD Inflammation Cohort (SCOPIC)

Background

To facilitate effective personalized medicine, primary health care needs better methods of assessing and monitoring chronic obstructive pulmonary disease (COPD).

Aim

This cohort study aims to investigate how biomarkers relate to clinical characteristics and COPD patients' subjective needs over time.

Methods

Patients (n=750) in different COPD severity according to the GOLD criteria and age- and sex-matched controls (n=750) will be recruited over a period of 5 years from 15 primary health care centers in Region Stockholm, Sweden, and followed for 10 years in the first instance. Data on patients' subjective needs will be collected via telephone/email, data on clinical/physiological variables (eg, symptoms, exacerbations, comorbidities, medications, smoking habits, lung function) from existing databases that are based on medical records, and data on biomarkers via repeated blood sampling. Quantitative and qualitative methods will be used. Initial results are expected after 2 years (feasibility test), and a larger body of evidence after 5 years.

Discussion

The study is expected to provide definitive and clinically useful scientific evidence about how biomarkers relate to clinical variables and patients' subjective needs. This new evidence will facilitate accurate, and personalized COPD management by the use of valid biomarkers. It will provide useful tools for primary care professionals and may facilitate optimal self-management.

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.

Suppressor of variegation 3-9 homologue 1 impairment and neutrophil-skewed systemic inflammation are associated with comorbidities in COPD

BACKGROUND

Systemic manifestations and comorbidities are characteristics of chronic obstructive pulmonary disease (COPD) and are probably due to systemic inflammation. The histone methyltransferase SUV39H1 controls the Th1/Th2 balance. We previously reported that reduced SUV39H1 expression contributed to abnormal inflammation in COPD. Here, we aimed to determine whether impaired SUV39H1 expression in COPD patients associated with neutrophilic/eosinophilic inflammation responses and comorbidities.

METHODS

A total of 213 COPD patients and 13 healthy controls were recruited from the Shuang Ho Hospital, Taipei Medical University. SUV39H1 levels in peripheral blood mononuclear cells (PBMCs) from 13 healthy and 30 COPD participants were measured by immunoblotting. We classified the patients into two groups based on low (fold change, FC < 0.5) and high SUV39H1 expression (FC ≥ 0.5) compared to normal controls. Clinical outcomes including neutrophil or eosinophil counts associated with SUV39H1-related inflammation were evaluated by Chi square analyses or Mann-Whitney U test. The correlations between the percentage of neutrophils and number of COPD comorbidities or Charlson Comorbidity Index (CCI) scores were performed by Spearman's rank analysis.

RESULTS

Low SUV39H1 expression group had high neutrophil counts relative to high SUV39H1expression group. In the COPD cohort, the high comorbidity group (≥ 2 comorbidities) had higher counts of whole white blood cell (WBC) and neutrophil, and lower proportion of eosinophil and eosinophil/neutrophil, as compared with low comorbidity group (0 and 1 comorbidities). The quantity of neutrophils was associated with COPD comorbidities (Spearman's r = 0.388, p < 0.001), but not with CCI scores. We also found that the high comorbidity group had more exacerbations per year compared with low comorbidity group (1.5 vs. 0.9 average exacerbations, p = 0.005). However, there were no significant differences between groups with these non-frequent (0-1 exacerbation) and frequent exacerbations per year (> 1 exacerbation) in numbers of WBC and proportion of neutrophils, eosinophils or eosinophil/neutrophil. Finally, patients with high comorbidities had lower SUV39H1 levels in their PBMCs than did those with low comorbidities.

CONCLUSION

Blood neutrophil counts are associated with comorbidities in COPD patients. Impaired SUV39H1 expression in PBMCs from COPD patients are correlated with neutrophilic inflammation and comorbidities.

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.

Eosinophilic phenotype was associated with better early clinical remission in elderly patients but not middle-aged patients with acute exacerbations of COPD

BACKGROUND

There is limited evidence of the relationship between peripheral blood eosinophils and clinical remission of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) at different ages, especially in elderly patients, which was the objective of the present study.

METHODS

This retrospective study stratified patients by age (elderly patients >65 years old or middle-aged patients between 45 and 65 years old) and analysed the relationship between blood eosinophils (≥2% or <2%) and AECOPD clinical remission at observing time points of 7, 14, 21 and 28 days of hospitalisation. Student's t tests, Mann-Whitney U tests, Chi-squared or Fisher's exact tests were conditionally used to compare difference between groups. The unadjusted or adjusted Cox proportional hazards model was used to analyse the association between blood eosinophilic levels and cumulative clinical remission.

RESULTS

Of 703 AECOPD cases analysed, 616 were elderly people (>65 years), 312 of whom had eosinophilic exacerbations. There were statistically significant differences in leucocytes, eosinophils, neutrophils, lymphocytes, monocytes, high-sensitivity C-reactive protein levels (hs-CRP), and hospital costs between groups (P < .05, respectively). According to the chi-square analysis, eosinophilic exacerbation had a higher clinical remission rate at 7, 14 and 21 days (all P < .05), but not 28 days (P > .05). Among analysis through adjusted Cox proportional hazards model, eosinophilic exacerbation was significantly associated with a higher cumulative remission rate in elderly patients at 7, 14, 21 days (all P < .05), but not 28 days (P > .05). No significant association was observed in meddle-aged patients at any time points (all P > .05).

CONCLUSION

Eosinophilic exacerbation was associated with better early clinical remission of AECOPD patients during hospitalisation. As stratified by ages, similar results were observed in elderly patients but not middle-aged patients. Blood eosinophils at different ages may be valuable in personalised management for AECOPD.

Phenotypic Variations of Mild-to-Moderate Obstructive Pulmonary Diseases According to Airway Inflammation and Clinical Features

Purpose

Asthma and chronic obstructive pulmonary disease (COPD) are complex and heterogeneous inflammatory diseases. We sought to investigate distinct disease profiles based on clinical, cellular and molecular data from patients with mild-to-moderate obstructive pulmonary diseases.

Patients and Methods

Patients with mild-to-moderate allergic asthma (n=30) and COPD (n=30) were prospectively recruited. Clinical characteristics and induced sputum were collected. In total, 35 mediators were assessed in induced sputum. Logistic regression analysis was conducted to identify the optimal factors that were able to discriminate between asthma and COPD. Further, the data were explored using hierarchical clustering in order to discover and compare clusters of combined samples of asthma and COPD patients. Clinical parameters, cellular composition, and sputum mediators of asthma and COPD were assessed between and within obtained clusters.

Results

We found five clinical and biochemical variables, namely IL-6, IL-8, CCL4, FEV₁/VC ratio pre-bronchodilator (%), and sputum neutrophils (%) that differentiated asthma and COPD and were suitable for discrimination purposes. A combination of those variables yielded high sensitivity and specificity in the differentiation between asthma and COPD, although only FEV₁/VC ratio pre-bronchodilator (%) proven significant in the combined model. In cluster analysis, two main clusters were identified: cluster 1, asthma predominant with evidence of eosinophilic airway inflammation and low level of Th1 and Th2 cytokines; and cluster 2, COPD predominant with elevated levels of Th1 and Th2 mediators.

Conclusion

The inflammatory profile of sputum samples from patients with stable mild-to-moderate asthma and COPD is not disease specific, varies within the disease and might be similar between these diseases. This study highlights the need for phenotyping the mild-to-moderate stages according to their clinical and molecular features.

Peripheral Blood Eosinophils and Nine Years Mortality in COPD Patients

Background

Eosinophil counts increase during chronic obstructive pulmonary disease (COPD) exacerbation and influence the response to different agents (such as inhaled and systemic corticosteroids), as well as increase the production of other inflammatory cytokines. However, few studies have evaluated the association between peripheral blood eosinophils with mortality rate.

Objective

To evaluate the association between peripheral blood eosinophils and mortality rate in COPD patients over a nine-year period.

Study Design and Methods

This cohort included 133 COPD patients assessed at baseline by spirometry, pulse oximetry (SpO₂), complete blood count, body composition, dyspnea intensity [Modified Medical Research Council (mMRC)] and the six-minute distance test (6MWD). The Kaplan-Meier curve followed by a Log rank test was used to evaluate mortality rate related to eosinophil cutoff point categorization. Multivariate Cox regression analysis was performed to identify the association between eosinophils and mortality with all subjects evaluated at baseline, adjusted for age, gender, mMRC, 6MWT, forced expiratory volume in the first second (FEV₁) and SpO₂.

Results

Nineteen patients did not complete follow-up and it was not possible to identify the date of death in four others. Therefore, 110 patients were included in the analysis. At baseline, 81% presented ≥150 eosinophil cells and 72% presented ≥2%. We identified a three-fold higher risk of death in those with <2% eosinophils and <150 cells. We did not identify statistical differences when using other cutoff points.

Conclusion

The decrease in number of peripheral eosinophils, with cutoff points at 2% and 150 cells, may be associated with a higher risk of death in COPD patients over nine years.

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.

Systemic Galectin-3 in Smokers with Chronic Obstructive Pulmonary Disease and Chronic Bronchitis: The Impact of Exacerbations

Purpose

The carbohydrate-binding protein Galectin-3 is increased in several inflammatory diseases and has recently been forwarded as a systemic biomarker in chronic obstructive pulmonary disease (COPD). In this longitudinal study, we characterized the level of systemic Galectin-3 using blood from smokers with a history of COPD and chronic bronchitis (COPD-CB), during stable clinical conditions and exacerbations.

Patients and Methods

The study population comprised 56 long-term smokers with COPD-CB, 10 long-term smokers without lung disease (LTS) and 10 clinically healthy never-smokers (HNS). Blood samples were analyzed for levels of Galectin-3, leukocyte populations and C-reactive protein (CRP). In addition, sputum samples from the COPD-CB group were analyzed for bacterial growth.

Results

When comparing stable clinical conditions and exacerbations in the COPD-CB group, we found that the level of Galectin-3, just like that of CRP, leukocytes and neutrophils, respectively, was increased during exacerbations. However, this exacerbation-associated increase of Galectin-3 was modest. During stable clinical conditions of COPD-CB, the level of Galectin-3 was not elevated in comparison with HNS or LTS. Nor did this level of Galectin-3 distinguish patients that remained in a clinically stable condition throughout the study to those that developed an exacerbation. In addition, neither during stable clinical conditions nor during exacerbations, did the presence of bacterial growth in sputum alter Galectin-3 levels. In contrast to Galectin-3, the level of CRP, leukocytes and neutrophils, respectively, were increased during clinical stable conditions in the COPD-CB group compared with the other groups and were further enhanced during exacerbations.

Conclusion

Systemic Galectin-3 is increased in a reproducible but modest manner during exacerbations in smokers with COPD-CB. During stable clinical conditions, the level of systemic Galectin-3 does not distinguish patients that remain clinically stable from those that develop exacerbations. This makes it less likely that systemic Galectin-3 may become a clinically useful biomarker in the current setting.

Blood Eosinophil and Risk of Exacerbation in Chronic Obstructive Pulmonary Disease Patients: A Retrospective Cohort Analysis

Purpose

Blood eosinophil is a readily available biomarker to reflect the eosinophilic inflammation in chronic obstructive pulmonary disease (COPD) patients, yet its association with exacerbation is inconclusive. It is uncertain which measurement, eosinophil percentage or absolute eosinophil count, should be used and what is the optimal cutoff for exacerbation prediction.

Patients and Methods

A total of 247 COPD patients were included in this retrospective cohort study. Blood eosinophil during stable disease state, baseline demographics, and clinical characteristics in 12 months after the index complete blood count (CBC) were recorded. Exacerbation frequencies were compared between patients with high and low blood eosinophil percentage using 2% as cut-off. Logistic regression and receiver operating characteristics (ROC) curve analyses were conducted.

Results

Patients with blood eosinophil ≥2% were associated with more frequent exacerbations than patients with eosinophil <2% in the 12 months after the index CBC (mean exacerbation 1.07 vs 0.34, p < 0.001). Higher blood eosinophil percentage conferred a higher risk of exacerbation. Adjusted odds ratio for exacerbation in 12 months after the index CBC for blood eosinophil ≥2% was 2.98 (95% confidence interval = 1.42–6.25). The area under the ROC curve of eosinophil percentage was significantly higher than that of absolute eosinophil count (0.678 vs 0.640, p = 0.010). The optimal cutoff of blood eosinophil percentage for exacerbation prediction was 2.8%.

Conclusion

Blood eosinophilia was associated with higher exacerbation risk in COPD patients. Further studies are required to elucidate the mechanism of eosinophilic inflammation in COPD and determine the optimal treatment strategy to reduce exacerbations.

Clinical characteristics of neutrophilic, eosinophilic and mixed-type exacerbation phenotypes of COPD

BACKGROUND

Chronic obstructive pulmonary disease (COPD) comprises a significant number of emergency department (ED) presentations, and hematological phenotypes may have prognostic significance. The aim of this study was to investigate the effect of hematological phenotypes on serious outcomes in COPD exacerbations.

METHODS

A prospective cohort study was carried out in patients with COPD exacerbation presenting to the ED. The patients were classified into three groups, including neutrophilic, eosinophilic, and mixed-type (including neutrophilic and eosinophilic features) COPD exacerbation. Outcome measures were defined as mortality, hospitalization, and need for intensive care unit (ICU) care within three months, and these outcomes were compared among groups.

RESULTS

A total of 173 COPD patients were assessed for eligibility, and 147 of them were included in the final analysis. The study population consisted of 90 patients with neutrophilic exacerbation (61.2%), 26 patients with eosinophilic exacerbation (17.7%), and 31 patients with mixed-type exacerbation (21.1%). The neutrophilic exacerbation group was older, was more often tachycardic and desaturated, and had more sputum production compared with the eosinophilic exacerbation group. Mortality was seen in 35 patients in the neutrophilic exacerbation group (38.9%), whereas 5 patients in the eosinophilic group (19.2%) and 6 patients in the mixed-type group (19.4%) died (p = .044). No difference was observed among groups in terms of hospital and ICU admission.

CONCLUSION

COPD exacerbations with neutrophilic phenotypes presented to the ED with more serious clinical findings compared with eosinophilic exacerbations. This may also have a possible effect on mortality.

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.

Disease burden of eosinophilic airway disease: Comparing severe asthma, COPD and asthma-COPD overlap

BACKGROUND AND OBJECTIVE

There is less understanding of phenotypes and disease burden in asthma-COPD overlap (ACO) than either disease alone. Blood eosinophils may help identify the patients in the clinic with eosinophilic airway inflammation. The potential value of this approach requires an understanding of the illness burden associated with eosinophilic ACO, eosinophilic severe asthma and eosinophilic COPD, defined by blood eosinophils.

METHODS

Participants from studies of multidimensional assessment in airway disease were pooled to identify patients with ACO (n = 106), severe asthma (n = 64) and COPD alone (n = 153). Patients were assessed cross-sectionally for demographic and clinical characteristics, including disease burden indicators such as health-related quality of life (HRQoL) and past-year exacerbation. Eosinophilic patients were identified using different thresholds of blood eosinophil count.

RESULTS

Using a blood eosinophil count ≥0.3 × 10⁹ /L, 41% had eosinophilic airway disease: 55% in ACO, 44% in severe asthma and 29% in COPD. Blood and sputum eosinophils were moderately correlated (r_s = 0.51, n = 257, P < 0.001). Burden of disease was similar between eosinophilic and non-eosinophilic airway diseases, with poor HRQoL and high number of past-year exacerbations. Burden of disease was similar across eosinophilic severe asthma, COPD and ACO. Eosinophilic COPD tended to have poorer health status than eosinophilic ACO and severe asthma; however, in context of a high prevalence of eosinophilic ACO, cumulative population-level burden of eosinophilic disease was greater in ACO.

CONCLUSION

Disease burden across eosinophilic ACO, eosinophilic severe asthma and eosinophilic COPD was high, particularly cumulative population-level burden in ACO. Factors beyond airway inflammation may drive disease burden in severe patients.

Elevated blood eosinophils in acute COPD exacerbations: better short- and long-term prognosis

Background: Elevated eosinophils in COPD is recognized as a potential risk factor for exacerbations, but the prognostic role of elevated eosinophils during exacerbations of COPD is unclear. We investigated short-term and long-term outcomes in patients with exacerbations of eosinophilic phenotype, compared with patients with low blood eosinophils. Methods: A single-centre retrospective study of all patients admitted for a COPD exacerbation to Bispebjerg University Hospital in 2010-2011 was established by linking inpatient data with national patient and prescription registries, with a three-year follow-up period. Elevated eosinophils were defined as a blood eosinophil level at admission of ≥0.30 × 10⁹ cells/L. Results: A total of 811 patients were included; 13.2% had an eosinophilic exacerbation. The eosinophilic group had less need for non-invasive ventilation, shorter inpatient stay, and lower in-hospital mortality, compared to the non-eosinophilic group. However, the eosinophilic and non-eosinophilic groups showed similar risks of readmission (incidence rate ratio[95], 0.99 [0.73-1.36]). Three-year mortality was high in both groups, although lower in the eosinophilic group (40% vs. 54%, p = 0.006). Conclusions: COPD exacerbations in patients with high blood eosinophil have a better short-term prognosis without higher risk of subsequent exacerbation. Eosinophilic exacerbations have also a lower three-year mortality.

[Study of the role of blood eosinophil count in patients with severe acute exacerbation of chronic obstructive pulmonary disease hospitalized in a Tunisian Center]

Introduction

There is a controversy over the relationship between blood eosinophil count (BEC) and the severity of chronic obstructive pulmonary disease (COPD) exacerbations. The purpose of our study was to determine the relationship between blood eosinophil count and multiple parameters in assessing the severity of serious acute exacerbation (AE) of obstructive pulmonary disease.

Methods

We conducted a retrospective monocentric study of hospitalized patients with obstructive pulmonary disease treated between 2005 and 2015. We compared 2 groups of patients: G1(BEC+): BEC ≥ 200 cell/μl (103 cases, 20.4%), G2(BEC-): BEC < 200 cell/μl (403 patients: 79.6%).

Results

A total of 506 subjects with obstructive pulmonary disease were included in the study. No significant difference between the two groups in age, gender, forced expiratory volume in one second (FEV1), and the number of AE/year (BEC+: 2.6, BEC-:2.5 AE/year; p = 0.48) was found. The analysis of the parameters of severity of serious AE showed no difference between the two groups in partial pressure of oxygen PaO2 measured on admission (60.5, 59.2 mmHg; p = 0.26), capnia (p=0.57), pH (p=0.74), C-reactive protein rate (mg/L) (82.7, 81; p = 0.89), leukocytosis (p = 0.36), non-invasive mechanical ventilation (5.8%, 6.5%; p = 0.81), invasive mechanical ventilation (p = 0.5),length of stay in hospital (9.7, 9 days; p = 0.21), mean time to next AECOPD (p = 0.32). Survival at 1 year was comparable between the two groups (94% vs 96%; Log Rank: 0.708).

Conclusion

Increased BEC in patients with COPD does not appear to have a negative effect on patients with severe AE. Despite the recent guidelines recommend to consider blood eosinophil count while making treatment decisions, the role and the prognostic interest of blood eosinophil count in patients with COPD could be population-dependent.

Exacerbation of eosinophilic COPD and pneumonia in post-treatment pulmonary multidrug-resistant tuberculosis patient: A case report

Eosinophilic chronic obstructive pulmonary disease (COPD) is a COPD phenotype with several clinical characteristics such as eosinophilic airway inflammation, more common in men and less severe COPD. Eosinophilic COPD has more exacerbations but responds well to corticosteroids and bronchodilators. We hereby report the case of a patient who came to us with shortness of breath, fever, wheezing and a cough with yellow phlegm. He had a history of smoking 4.5 pack-year and two episodes of pulmonary tuberculosis (the second was pulmonary multidrug-resistant tuberculosis). He was diagnosed with eosinophilic COPD exacerbation and pneumonia. Intravenous corticosteroids, bronchodilators and antibiotics were given and his condition improved after a week of hospitalisation. Smoking and pulmonary tuberculosis are risk factors for COPD. In this case, irreversible airflow obstruction is related to COPD and also pulmonary TB. There are several mechanisms that cause airway obstruction in pulmonary tuberculosis, one of which is persistent mycobacterium acting as a co-factor along with smoking and several environmental factors that cause chronic airway inflammation and result in bronchial narrowing with or without parenchymal destruction.

[Eosinophilic inflammation in chronic obstructive pulmonary disease]

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease that combines various clinical manifestations and pathophysiological mechanisms. It underlies the separation of patients with COPD by phenotypes, endotypes and a personalized therapy of this disease. The implementation of this approach is possible only with the use of appropriate biomarkers. One of the most important biomarkers of COPD is eosinophilia of blood and/or sputum, which is considered as a predictor of frequent exacerbations and the effectiveness of inhaled glucocorticosteroids in patients with COPD. The literature discusses the impact of eosinophilic inflammation on the prognosis, clinical and functional parameters in COPD, and the role of the targeted therapy in the treatment of eosinophilic COPD.

Blood eosinophils could be useful as a biomarker in chronic obstructive pulmonary disease exacerbations

Introduction The aim of analysing the usefulness of the blood eosinophil count (BEC) as a prognostic marker in exacerbations of patients with Chronic Obstructive Pulmonary Disease (COPD), evaluating its relationship with hospital mortality, the length of stay and the early and late re-admissions. Materials and Methods We have carried out a retrospective study including all patients who required hospital admission from 1 January 2008 to 31 December 2009, with a diagnosis on hospital discharge of COPD exacerbation. These patients were classified using three cut-off points of BEC: less than 200 vs ≥ 200/µL, less than 300 vs ≥ 300/µL and less than 400 vs ≥ 400/µL. Results There were a total of 1626 hospital admissions during the study period with the diagnosis of exacerbation of COPD. In this study we have included 358 patients. The probability of any late re-admission increased with a BEC ≥ 300/µL (odds ratio: 1.684) and for those with a BEC ≥ 400/µL (odds ratio: 2.068). The BEC does not appear to be related to hospital mortality or the probability of early re-admission after an exacerbation of COPD. Conclusions In our study an elevated BEC is associated with a higher incidence of late hospital readmissions in COPD exacerbations.

The association between airflow limitation and blood eosinophil levels with treatment outcomes in patients with chronic obstructive pulmonary disease and prolonged mechanical ventilation

The clinical implications of airflow limitation severity and blood eosinophil level in patients with chronic obstructive pulmonary disease (COPD) and prolonged mechanical ventilation (PMV) are unknown. Thus, this study aimed to identify whether or not these two indicators were significantly associated with short-term in-respiratory care center (RCC) treatment outcomes in this population. Of all participants (n = 181) in this retrospective cross-sectional study, 41.4%, 40.9%, 8.3%, and 52.5% had prolonged RCC admission (RCC length of stay >21 days), failed weaning, death, and any adverse outcomes of interest, respectively. Compared to participants without any adverse outcomes of interest, moderate (the Global Initiative for Chronic Obstructive Lung Disease (GOLD) II) and/or severe (GOLD III) airflow limitation were significantly associated with short-term in-RCC adverse outcomes in terms of failed weaning (for III versus I, OR = 15.06, p = 0.003) and having any adverse outcomes of interest (for II versus I, OR = 17.66, p = 0.002; for III versus I, OR = 37.07, p = 0.000) though the severity of airflow limitation did not have associations with prolonged RCC admission and death after adjustment. Meanwhile, blood eosinophilia defined by various cut-off values was not associated with any adverse outcomes. The findings have significant clinical implications and are useful in the management of patients with COPD and PMV.

New therapeutic targets for the prevention of infectious acute exacerbations of COPD: role of epithelial adhesion molecules and inflammatory pathways

Chronic respiratory diseases are among the leading causes of mortality worldwide, with the major contributor, chronic obstructive pulmonary disease (COPD) accounting for approximately 3 million deaths annually. Frequent acute exacerbations (AEs) of COPD (AECOPD) drive clinical and functional decline in COPD and are associated with accelerated loss of lung function, increased mortality, decreased health-related quality of life and significant economic costs. Infections with a small subgroup of pathogens precipitate the majority of AEs and consequently constitute a significant comorbidity in COPD. However, current pharmacological interventions are ineffective in preventing infectious exacerbations and their treatment is compromised by the rapid development of antibiotic resistance. Thus, alternative preventative therapies need to be considered. Pathogen adherence to the pulmonary epithelium through host receptors is the prerequisite step for invasion and subsequent infection of surrounding structures. Thus, disruption of bacterial-host cell interactions with receptor antagonists or modulation of the ensuing inflammatory profile present attractive avenues for therapeutic development. This review explores key mediators of pathogen-host interactions that may offer new therapeutic targets with the potential to prevent viral/bacterial-mediated AECOPD. There are several conceptual and methodological hurdles hampering the development of new therapies that require further research and resolution.

Relationship between the respiratory microbiome and the severity of airflow limitation, history of exacerbations and circulating eosinophils in COPD patients

Background

The respiratory microbiome is altered in COPD patients but its relationship with core components of the disease, such as the severity of airflow limitation, the frequency of exacerbations or the circulating levels of eosinophils, is unclear.

Methods

Cross-sectional study comprising 72 clinically stable COPD patients (mean age 68 [SD 7.9] years; FEV1 48.7 [SD 20.1]% of reference) who provided spontaneous sputum samples for 16S rRNA gene amplification and sequencing. The microbiome composition was analysed with QIIME.

Results

We observed that: (1) more severe airflow limitation was associated with reduced relative abundance (RA) of Treponema and an increase in Pseudomonas; (2) patients with ≥2 exacerbations the previous year showed a significantly different bacterial community with respect to non-exacerbators (p = 0.014), with changes in 13 genera, including an increase of Pseudomonas, and finally, (3) peripheral eosinophils levels ≥2% were associated with more diverse microbiome [Chao1 224.51 (74.88) vs 277.39 (78.92) p = 0.006; Shannon 3.94 (1.05) vs 4.54 (1.06) p = 0.020], and a significant increase in the RAs of 20 genera.

Conclusion

The respiratory microbiome in clinically stable COPD patients varies significantly according to the severity of airflow limitation, previous history of exacerbations and circulating eosinophils levels.

Electronic supplementary material

The online version of this article (10.1186/s12890-019-0867-x) contains supplementary material, which is available to authorized users.

Clinical features, bacteriology of endotracheal aspirates and treatment outcomes of patients with chronic obstructive pulmonary disease and community-acquired pneumonia in an intensive care unit in Taiwan with an emphasis on eosinophilia versus non-eosinophilia: a retrospective case-control study

OBJECTIVES

The clinical implications of blood eosinophil level in patients with chronic obstructive pulmonary disease (COPD) and community-acquired pneumonia (CAP) requiring invasive mechanical ventilation (IMV) and intensive care unit (ICU) admission are still unknown. Thus, this study aimed to compare the features of such patients with and without blood eosinophilia.

DESIGN

This was a retrospective case-control study.

SETTING

An ICU of a medical centre in central Taiwan.

PARTICIPANTS

A total of 262 patients with COPD and CAP requiring IMV and ICU admission.

RESULTS

Of all participants (n=262), 32 (12.2%) had an eosinophil percentage (EP) >2% and 169 (64.5%) had an absolute eosinophil count (AEC) >300 cells/µL. Regardless of whether 2% or 300 cells/µL was used as a cut-off value, the eosinophilia group were slightly older (years) (82.9±5.4 vs 78.1±9.1, p=0.000 and 79.2±8.4 vs 77.6±9.6, p=0.246, respectively), and had a higher forced expiratory volume in 1 s/forced vital capacity (%) (56.0±8.0 vs 51.3±11.6, p=0.005 and 53.1±11.2 vs 49.5±11.2, p=0.013, respectively), less severe spirometric classification (p=0.008 and p=0.001, respectively), and lower white cell count 109/L (8.8±3.2 vs 11.1±4.9, p=0.009 and 10.3±4.4 vs 11.8±5.3, p=0.017, respectively) than the non-eosinophilia group. The bacteriology of endotracheal aspirates showed that Pseudomonas aeruginosa and other gram-negative bacilli were the most common organisms in all study groups. Participants with an EP >2% had a shorter ICU length of stay (OR=12.13, p=0.001) than those with an EP ≤2%, while an AEC >300 cells/µL was not associated with any in-ICUoutcomes.

CONCLUSIONS

The results of this study have significant clinical implications and should be considered when making treatment decisions for the management of patients with COPD and CAP requiring IMV and ICU admission.

Chronic Rhinitis Is a High-Risk Comorbidity for 30-Day Hospital Readmission of Patients with Asthma and Chronic Obstructive Pulmonary Disease

BACKGROUND

Early hospital readmissions for asthma and chronic obstructive pulmonary disease (COPD), measured as hospital readmission within 30 days from the last discharge, is a major economic burden to our health care system. The association of this measure with comorbid chronic rhinitis (CR) has not been investigated before despite significant clinical association between CR and asthma or COPD.

OBJECTIVE

To investigate the association of CR with the risk of asthma or COPD-related early hospital readmission rates.

METHODS

This retrospective cohort study was performed using the asthma- and COPD-related hospital encounter and patient comorbidity data between June 15, 2012, and July 19, 2017, from a large hospital care system in Cincinnati, Ohio. Patients (any sex, race or socioeconomic status, and of all ages) with a primary discharge diagnosis of asthma (n = 4754 patients, 10,111 encounters) and COPD (n = 2176 patients, 4748 encounters) based on International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) codes were included. Relevant comorbidities, including comorbid allergic rhinitis (AR) or nonallergic rhinitis (NAR), in such patients were identified using ICD-10-CM codes. The association between 30-day asthma or COPD-related hospital readmission (1670 such encounters for asthma and 736 for COPD) and comorbid CR in the affected patients were determined using Cox proportional hazards models. Multivariate-adjusted hazard ratios (HRs), adjusted for relevant patient comorbidities, compared 30-day asthma- and COPD-related readmissions of patients with CR with those patients without a CR diagnosis.

RESULTS

Analysis was performed on 4754 patients with asthma and 2176 patients with COPD. The median follow-up period (+interquartile range) for asthma was 980 (+760) days and for COPD was 553 (+827) days. The HRs for 30-day asthma- or COPD-related readmission rates were significantly higher in patients with AR (HR = 4.4 [3.9, 5.0] and 2.4 [1.7, 3.2], respectively) or NAR (HR = 3.7 [2.9, 4.9] and 2.6 [1.8, 3.7], respectively) compared with patients without rhinitis. For asthma, both AR and NAR had higher HRs compared with all other comorbidities analyzed. For COPD, both AR and NAR had HRs to the magnitude as obesity and hypertension.

CONCLUSIONS

Comorbid CR is significantly associated with 30-day asthma- and COPD-related readmissions. These findings are useful for guiding health care professionals to focus on outpatient management of both the upper and lower respiratory tracts to reduce early readmission of patients with asthma and COPD.

Blood eosinophil count thresholds and exacerbations in patients with chronic obstructive pulmonary disease

BACKGROUND

Eosinophilic airway inflammation in patients with chronic obstructive pulmonary disease (COPD) is associated with exacerbations and responsivity to steroids, suggesting potential shared mechanisms with eosinophilic asthma. However, there is no consistent blood eosinophil count that has been used to define the increased exacerbation risk.

OBJECTIVE

We sought to investigate blood eosinophil counts associated with exacerbation risk in patients with COPD.

METHODS

Blood eosinophil counts and exacerbation risk were analyzed in patients with moderate-to-severe COPD by using 2 independent studies of former and current smokers with longitudinal data. The Genetic Epidemiology of COPD (COPDGene) study was analyzed for discovery (n = 1,553), and the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study was analyzed for validation (n = 1,895). A subset of the ECLIPSE study subjects were used to assess the stability of blood eosinophil counts over time.

RESULTS

COPD exacerbation risk increased with higher eosinophil counts. An eosinophil count threshold of 300 cells/μL or greater showed adjusted incidence rate ratios for exacerbations of 1.32 in the COPDGene study (95% CI, 1.10-1.63). The cutoff of 300 cells/μL or greater was validated for prospective risk of exacerbation in the ECLIPSE study, with adjusted incidence rate ratios of 1.22 (95% CI, 1.06-1.41) using 3-year follow-up data. Stratified analysis confirmed that the increased exacerbation risk associated with an eosinophil count of 300 cells/μL or greater was driven by subjects with a history of frequent exacerbations in both the COPDGene and ECLIPSE studies.

CONCLUSIONS

Patients with moderate-to-severe COPD and blood eosinophil counts of 300 cells/μL or greater had an increased risk exacerbations in the COPDGene study, which was prospectively validated in the ECLIPSE study.