Eosinophilic airway inflammation and exacerbations of COPD: a randomised controlled trial

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Treatable traits models of care

Treatable traits is a personalized approach to the management of respiratory disease. The approach involves a multidimensional assessment to understand the traits present in individual patients. Traits are phenotypic and endotypic characteristics that can be identified, are clinically relevant and can be successfully treated by therapy to improve clinical outcomes. Identification of traits is followed by individualized and targeted treatment to those traits. First proposed for the management of asthma and chronic obstructive pulmonary disease (COPD) the approach is recommended in many other areas of respiratory and now immunology medicine. Models of care for treatable traits have been proposed in different diseases and health care setting. In asthma and COPD traits are identified in three domains including pulmonary, extrapulmonary and behavioural/lifestyle/risk-factors. In bronchiectasis and interstitial lung disease, a fourth domain of aetiological traits has been proposed. As the core of treatable traits is personalized and individualized medicine; there are several key aspects to treatable traits models of care that should be considered in the delivery of care. These include person centredness, consideration of patients' values, needs and preferences, health literacy and engagement. We review the models of care that have been proposed and provide guidance on the engagement of patients in this approach to care.

Therapeutic Targets and Precision Medicine in COPD: Inflammation, Ion Channels, Both, or Neither?

The development of a wider range of therapeutic options is a key objective in drug discovery for chronic obstructive pulmonary disease (COPD). Fundamental advances in lung biology have the potential to greatly expand the number of therapeutic targets in COPD. The recently reported successful Phase 3 clinical trial of the first biologic agent for COPD, the monoclonal antibody dupilumab, adds additional support to the importance of targeting inflammatory pathways in COPD. However, numerous other cellular mechanisms are important targets in COPD therapeutics, including airway remodeling, the CFTR ion channel, and mucociliary function. Some of these emerging targets can be exploited by the expanded use of existing COPD drugs, such as roflumilast, while targeting others will require the development of novel molecular entities. The identification of additional therapeutic targets and agents has the potential to greatly expand the value of using clinical and biomarker data to classify COPD into specific subsets, each of which can be predictive of an enhanced response to specific subset(s) of targeted therapies. The author reviews established and emerging drug targets in COPD and uses this as a framework to define a novel classification of COPD based on therapeutic targets. This novel classification has the potential to enhance precision medicine in COPD patient care and to accelerate clinical trials and pre-clinical drug discovery efforts.

Inhaled corticosteroids with combination inhaled long-acting beta2-agonists and long-acting muscarinic antagonists for chronic obstructive pulmonary disease

BACKGROUND

Management of chronic obstructive pulmonary disease (COPD) commonly involves a combination of long-acting bronchodilators including beta2-agonists (LABA) and muscarinic antagonists (LAMA). LABA and LAMA bronchodilators are now available in single-combination inhalers. In individuals with persistent symptoms or frequent exacerbations, inhaled corticosteroids (ICS) are also used with combination LABA and LAMA inhalers. However, the benefits and risks of adding ICS to combination LABA/LAMA inhalers as a triple therapy remain unclear.

OBJECTIVES

To assess the effects of adding an ICS to combination LABA/LAMA inhalers for the treatment of stable COPD.

SEARCH METHODS

We searched the Cochrane Airways Group Register of Trials, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase up to 30 November 2022. We also searched ClinicalTrials.gov and the WHO ICTRP up to 30 November 2022.

SELECTION CRITERIA

We included parallel-group randomised controlled trials of three weeks' duration or longer that compared the treatment of stable COPD with ICS in addition to combination LABA/LAMA inhalers against combination LABA/LAMA inhalers alone.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. The primary outcomes were acute exacerbations of COPD, respiratory health-related quality of life, pneumonia and other serious adverse events. The secondary outcomes were symptom scores, lung function, physical capacity, and mortality. We used GRADE to assess certainty of evidence for studies that contributed data to our prespecified outcomes.

MAIN RESULTS

Four studies with a total of 15,412 participants met the inclusion criteria. The mean age of study participants ranged from 64.4 to 65.3 years; the proportion of female participants ranged from 28% to 40%. Most participants had symptomatic COPD (COPD Assessment Test Score ≥ 10) with severe to very severe airflow limitation (forced expiratory volume in one second (FEV1) < 50% predicted) and one or more moderate-to-severe COPD exacerbations in the last 12 months. Trial medications differed amongst studies. The duration of follow-up was 52 weeks in three studies and 24 weeks in one study. We assessed the risk of selection, performance, and detection bias to be low in the included studies; one study was at high risk of attrition bias, and one study was at high risk of reporting bias. Triple therapy may reduce rates of moderate-to-severe COPD exacerbations compared to combination LABA/LAMA inhalers (rate ratio (RR) 0.74, 95% confidence interval (CI) 0.67 to 0.81; n = 15,397; low-certainty evidence). Subgroup analysis stratifying by blood eosinophil counts showed there may be a greater reduction in rate of moderate-to-severe COPD exacerbations with triple therapy in participants with high-eosinophils (RR 0.67, 95% CI 0.60 to 0.75) compared to low-eosinophils (RR 0.87, 95% CI 0.81 to 0.93) (test for subgroup differences: P < 0.01) (high/low cut-offs: 150 eosinophils/µL in three studies; 200 eosinophils/µL in one study). However, moderate-to-substantial heterogeneity was observed in both high- and low-eosinophil subgroups. These subgroup analyses are observational by nature and thus results should be interpreted with caution. Triple therapy may be associated with reduced rates of severe COPD exacerbations (RR 0.75, 95% CI 0.67 to 0.84; n = 14,131; low-certainty evidence). Triple therapy improved health-related quality of life assessed using the St George's Respiratory Questionnaire (SGRQ) by the minimal clinically important difference (MCID) threshold (4-point decrease) (35.3% versus 42.4%, odds ratio (OR) 1.35, 95% CI 1.26 to 1.45; n = 14,070; high-certainty evidence). Triple therapy may result in fewer symptoms measured using the Transition Dyspnoea Index (TDI) (OR 1.33, 95% CI 1.13 to 1.57; n = 3044; moderate-certainty evidence) and improved lung function as measured by change in trough FEV1 (mean difference 38.68 mL, 95% CI 22.58 to 54.77; n = 11,352; low-certainty evidence). However, these benefits fell below MCID thresholds for TDI (1-unit decrease) and trough FEV1 (100 mL), respectively. Triple therapy is probably associated with a higher risk of pneumonia as a serious adverse event compared to combination LABA/LAMA inhalers (3.3% versus 1.9%, OR 1.74, 95% CI 1.39 to 2.18; n = 15,412; moderate-certainty evidence). In contrast, all-cause serious adverse events may be similar between groups (19.7% versus 19.7%, OR 0.95, 95% CI 0.87 to 1.03; n = 15,412; low-certainty evidence). All-cause mortality may be lower with triple therapy (1.4% versus 2.0%, OR 0.70, 95% CI 0.54 to 0.90; n = 15,397; low-certainty evidence).

AUTHORS' CONCLUSIONS

The available evidence suggests that triple therapy may reduce rates of COPD exacerbations (low-certainty evidence) and results in an improvement in health-related quality of life (high-certainty evidence) compared to combination LABA/LAMA inhalers, but probably confers an increased pneumonia risk as a serious adverse event (moderate-certainty evidence). Triple therapy probably improves respiratory symptoms and may improve lung function (moderate- and low-certainty evidence, respectively); however, these benefits do not appear to be clinically significant. Triple therapy may reduce the risk of all-cause mortality compared to combination LABA/LAMA inhalers (low-certainty evidence). The certainty of the evidence was downgraded most frequently for inconsistency or indirectness. Across the four included studies, there were important differences in inclusion criteria, trial medications, and duration of follow-up. Investigation of heterogeneity was limited due to the small number of included studies. We found limited data on the effects of triple therapy compared to combination LABA/LAMA inhalers in patients with mild-moderate COPD and those without a recent exacerbation history.

Association between Galectin-13 Expression and Eosinophilic Airway Inflammation in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) and asthma are chronic inflammatory diseases of the airways. Galectin-13 has recently been forwarded as a biomarker for airway eosinophilic inflammation in asthma. However, the association between galectin-13 and COPD remains unknown. To examine the changes in galectin-13 expression in acute exacerbations of COPD (AECOPD) and the stable phase of COPD and unveil the association between galectin-13 expression and eosinophilic inflammation in COPD, we measured plasma galectin-13 expression in different phases of COPD patients (n = 60, 44 AECOPD patients, and 16 stable COPD patients) and healthy controls (n = 15). Plasma levels of galectin-13 in 60 COPD patients were further analyzed and compared to systemic inflammation, airway eosinophilic inflammation, and lung function. The plasma galectin-13 level was markedly increased in subjects with AECOPD compared to stable COPD patients and healthy controls. Plasma galectin-13 levels in COPD subjects were positively correlated with serum CRP (r_s = 0.46, p = 0.0003), peripheral blood eosinophilia count (r_s = 0.57, p<0.0001), and FeNO (r_s = 0.46, p = 0.0002). In addition, the level of galectin-13 was negatively correlated with FEV₁ (r_s = -0.43, p = 0.0001), FEV₁ pred (%) (r_s = -0.544, p<0.0001), as well as FEV₁/FVC (r_s = -0.46, p<0.0001). Multiple linear regression analysis suggested that plasma galectin-13 levels were affected by FEV₁ pred (%), peripheral blood eosinophilia count, and FeNO. We concluded that galectin-13 levels were increased in COPD patients, and elevated galectin-13 expressions related to airway eosinophilic inflammation. Galectin-13 may facilitate the identification of COPD endotypes and may become a potential therapeutic target.

Dupilumab for COPD with Type 2 Inflammation Indicated by Eosinophil Counts

BACKGROUND

In some patients with chronic obstructive pulmonary disease (COPD), type 2 inflammation may increase exacerbation risk and may be indicated by elevated blood eosinophil counts. Dupilumab, a fully human monoclonal antibody, blocks the shared receptor component for interleukin-4 and interleukin-13, key drivers of type 2 inflammation.

METHODS

In a phase 3, double-blind, randomized trial, we assigned patients with COPD who had a blood eosinophil count of at least 300 per microliter and an elevated exacerbation risk despite the use of standard triple therapy to receive dupilumab (300 mg) or placebo subcutaneously once every 2 weeks. The primary end point was the annualized rate of moderate or severe exacerbations of COPD. Key secondary and other end points that were corrected for multiplicity were the change in the prebronchodilator forced expiratory volume in 1 second (FEV1) and in the scores on the St. George's Respiratory Questionnaire (SGRQ; range, 0 to 100, with lower scores indicating a better quality of life) and the Evaluating Respiratory Symptoms in COPD (E-RS-COPD; range, 0 to 40, with lower scores indicating less severe symptoms).

RESULTS

A total of 939 patients underwent randomization: 468 to the dupilumab group and 471 to the placebo group. The annualized rate of moderate or severe exacerbations was 0.78 (95% confidence interval [CI], 0.64 to 0.93) with dupilumab and 1.10 (95% CI, 0.93 to 1.30) with placebo (rate ratio, 0.70; 95% CI, 0.58 to 0.86; P<0.001). The prebronchodilator FEV1 increased from baseline to week 12 by a least-squares (LS) mean of 160 ml (95% CI, 126 to 195) with dupilumab and 77 ml (95% CI, 42 to 112) with placebo (LS mean difference, 83 ml; 95% CI, 42 to 125; P<0.001), a difference that was sustained through week 52. At week 52, the SGRQ score had improved by an LS mean of -9.7 (95% CI, -11.3 to -8.1) with dupilumab and -6.4 (95% CI, -8.0 to -4.8) with placebo (LS mean difference, -3.4; 95% CI, -5.5 to -1.3; P = 0.002). The E-RS-COPD score at week 52 had improved by an LS mean of -2.7 (95% CI, -3.2 to -2.2) with dupilumab and -1.6 (95% CI, -2.1 to -1.1) with placebo (LS mean difference, -1.1; 95% CI, -1.8 to -0.4; P = 0.001). The numbers of patients with adverse events that led to discontinuation of dupilumab or placebo, serious adverse events, and adverse events that led to death were balanced in the two groups.

CONCLUSIONS

Among patients with COPD who had type 2 inflammation as indicated by elevated blood eosinophil counts, those who received dupilumab had fewer exacerbations, better lung function and quality of life, and less severe respiratory symptoms than those who received placebo. (Funded by Sanofi and Regeneron Pharmaceuticals; BOREAS ClinicalTrials.gov number, NCT03930732.).

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.

Anti-IL5/IL5R Treatment in COPD: Should We Target Oral Corticosteroid-Dependent Patients?

Introduction

Monoclonal antibodies targeting interleukin 5 (IL5) or its receptor (IL5R) are frequently used in severe asthma, in which they reduce exacerbations rate and oral corticosteroids (OCS) exposure. Anti-IL5/IL5Rs have been studied in patients with chronic obstructive pulmonary disease (COPD) without convincing benefits. However, these therapies have been used in clinical practice in COPD with apparently good results.

Purpose

To describe the clinical characteristics and therapeutic response of COPD patients treated with anti-IL5/IL5R in a real-world setting.

Patients and Methods

This is a retrospective case series of patients followed at the Quebec Heart and Lung Institute COPD clinic. Men or women, with an established diagnosis of COPD, and treated either with Mepolizumab or Benralizumab were included. Demographics, disease and exacerbation-related data, airway comorbidities, lung function, and inflammatory profile were extracted from patients' hospital files at baseline visit and 12 months post-treatment. Therapeutic response to biologics was assessed by measuring change in annual exacerbation rate and/or OCS daily dose.

Results

Seven COPD patients treated with biologics were identified (5M:2F). All were found to be OCSdependent at baseline. Radiological evidence of emphysema was found in all patients. One case was diagnosed with asthma before age 40. Residual eosinophilic inflammation was found in 5/6 patients (blood eosinophils count 237 ± 225×106 cells/L) despite chronic OCS use. After 12 months of anti-IL5 treatment, mean OCS dose dropped from 12.0 ± 7.6 to 2.6 ± 4.3 mg/day, representing a 78% decrease. Annual exacerbations rate was reduced by 88%, from 8.2 ± 3.3 to 1.0 ± 1.2 per year.

Conclusion

Chronic OCS use is a common characteristic of patients treated with anti-IL5/IL5R biological therapies in this real-world setting. In this population, it may be effective in decreasing OCS exposure and exacerbation.

The clinical efficacy of type 2 monoclonal antibodies in eosinophil-associated chronic airway diseases: a meta-analysis

Background

Anti-type 2 inflammation therapy has been proposed as a treatment strategy for eosinophil-associated chronic airway disorders that could reduce exacerbations and improve lung function. We performed a meta-analysis of randomized controlled trials to assess the effectiveness of type 2 monoclonal antibodies (anti-T2s) for eosinophil-associated chronic airway disorders.

Methods

PubMed, Embase, Web of Science, and Cochrane Library were searched from their inception to 21 August 2022. Randomized clinical trials evaluating the effectiveness of anti-T2s versus placebo in the treatment of chronic airway diseases were selected. The outcomes were exacerbation rate and change in pre-bronchodilator forced expiratory volume in 1 s (FEV1) from baseline. The Cochrane Risk of Bias Assessment Tool 1.0 was used to evaluate the risk of bias, and the random-effects or fixed-effect model were used to pool the data.

Results

Thirty-eight articles concerning forty-one randomized clinical trials with 17,115 patients were included. Compared with placebo, anti-T2s therapy yielded a significant reduction in exacerbation rate in COPD and asthma (Rate Ratio (RR)=0.89, 95%CI, 0.83-0.95, I2 = 29.4%; RR= 0.59, 95%CI, 0.52-0.68, I2 = 83.9%, respectively) and improvement in FEV1 in asthma (Standard Mean Difference (SMD)=0.09, 95%CI, 0.08-0.11, I2 = 42.6%). Anti-T2s therapy had no effect on FEV1 improvement in COPD (SMD=0.05, 95%CI, -0.01-0.10, I2 = 69.8%).

Conclusion

Despite inconsistent findings across trials, anti-T2s had a positive overall impact on patients' exacerbation rate in asthma and COPD and FEV1 in asthma. Anti-T2s may be effective in treating chronic airway illnesses related to eosinophils.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022362280.

Lung microbiome and cytokine profiles in different disease states of COPD: a cohort study

Increasing evidence indicates that respiratory tract microecological disorders may play a role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Understanding the composition of the respiratory microbiome in COPD and its relevance to respiratory immunity will help develop microbiome-based diagnostic and therapeutic approaches. One hundred longitudinal sputum samples from 35 subjects with acute exacerbation of COPD (AECOPD) were analysed for respiratory bacterial microbiome using 16S ribosomal RNA amplicon sequencing technology, and the sputum supernatant was analysed for 12 cytokines using a Luminex liquid suspension chip. Unsupervised hierarchical clustering was employed to evaluate the existence of distinct microbial clusters. In AECOPD, the respiratory microbial diversity decreased, and the community composition changed significantly. The abundances of Haemophilus, Moraxella, Klebsiella, and Pseudomonas increased significantly. Significant positive correlations between the abundance of Pseudomonas and TNF-α, abundance of Klebsiella and the percentage of eosinophils were observed. Furthermore, COPD can be divided into four clusters based on the respiratory microbiome. AECOPD-related cluster was characterized by the enrichment of Pseudomonas and Haemophilus and a high level of TNF-α. Lactobacillus and Veillonella are enriched in therapy-related phenotypes and may play potential probiotic roles. There are two inflammatory endotypes in the stable state: Gemella is associated with the Th2 inflammatory endotypes, whereas Prevotella is associated with the Th17 inflammatory endotypes. Nevertheless, no differences in clinical manifestations were found between these two endotypes. The sputum microbiome is associated with the disease status of COPD, allowing us to distinguish different inflammatory endotypes. Targeted anti-inflammatory and anti-infective therapies may improve the long-term prognosis of COPD.

A four-part guide to lung immunology: Invasion, inflammation, immunity, and intervention

Lungs are important respiratory organs primarily involved in gas exchange. Lungs interact directly with the environment and their primary function is affected by several inflammatory responses caused by allergens, inflammatory mediators, and pathogens, eventually leading to disease. The immune architecture of the lung consists of an extensive network of innate immune cells, which induce adaptive immune responses based on the nature of the pathogen(s). The balance of immune responses is critical for maintaining immune homeostasis in the lung. Infection by pathogens and physical or genetic dysregulation of immune homeostasis result in inflammatory diseases. These responses culminate in the production of a plethora of cytokines such as TSLP, IL-9, IL-25, and IL-33, which have been implicated in the pathogenesis of several inflammatory and autoimmune diseases. Shifting the balance of Th1, Th2, Th9, and Th17 responses have been the targets of therapeutic interventions in the treatment of these diseases. Here, we have briefly reviewed the innate and adaptive i3mmune responses in the lung. Genetic and environmental factors, and infection are the major causes of dysregulation of various functions of the lung. We have elaborated on the impact of inflammatory and infectious diseases, advances in therapies, and drug delivery devices on this critical organ. Finally, we have provided a comprehensive compilation of different inflammatory and infectious diseases of the lungs and commented on the pros and cons of different inhalation devices for the management of lung diseases. The review is intended to provide a summary of the immunology of the lung, with an emphasis on drug and device development.

Treatable Traits in Airway Disease: From Theory to Practice

Chronic airway diseases such as asthma and chronic obstructive pulmonary disease are prevalent and complex conditions that often coexist in the same patient. To address this complexity in clinical practice, and to move forward toward personalized and precision medicine of airway diseases, a strategy based on the identification and treatment of so-called "treatable traits" (TTs) has been proposed. A TT is a recognizable phenotypic or endotypic characteristic that can be assessed and successfully targeted by therapy to improve a clinical outcome in a patient with airway disease. Importantly, TTs can coexist in the same patient, so they are not mutually exclusive. The TT strategy proposes to investigate in each individual patient with chronic airway disease the number and type of TTs present and to treat each of them according to guideline recommendations. This strategy is agnostic (ie, independent) to the traditional diagnostic labels (asthma, chronic obstructive pulmonary disease), so it can be applied to any patient with airway disease. Currently, there is firm evidence supporting the adequacy and validity of the TT strategy. Here, we review the current state of the art of this topic, first by presenting its theoretical background and then by discussing how to best implement it in clinical practice.

Chronic Obstructive Pulmonary Disease Patients With High Peripheral Blood Eosinophil Counts Have Better Predicted Improvement in 6MWD After Rehabilitation: A PRELIMINARY STUDY

PURPOSE

The objective of this investigation was to determine whether chronic obstructive pulmonary disease (COPD) patients with high blood eosinophil (EOS) counts had better improvement in 6-min walk test (6MWT) after pulmonary rehabilitation (PR).

METHODS

Fifty COPD patients were randomly assigned to either the rehabilitation group (RG) or the control group (CG). Patients in the RG (8 wk PR + routine medication) and the CG (routine medication) were followed for 32 wk. According to the blood EOS level, the RG was divided into an EOS ≥ 200 cells/μL group and EOS < 200 cells/μL group. The 6MWT distance, Borg Scale, and COPD Assessment Test (CAT) were evaluated before intervention and 8 wk and 32 wk later.

RESULTS

After the 8-wk intervention, 37 patients (19 RG/18 CG) completed the study. At 8-wk and 32-wk follow-up from baseline, a statistically significant difference was found between these two groups in the 6MWT, Borg Scale, and CAT. Compared with baseline, the 6MWT in the RG increased 49.1 ± 40.2 m (95% CI, 29.7-68.5, P < .001) at 8 wk and 60.8 ± 42.1 m (95% CI, 40.5-81.6, P < .001) at 32 wk. In addition, the improvement of 6MWT in the EOS ≥ 200 cells/μL RG group was higher than that in the EOS < 200 cells/μL group (40.1 ± 17.6 m, 95% CI, 36.8-43.4; P = .036) at 32-wk follow-up from baseline.

CONCLUSION

An 8-wk PR can improve the exercise capacity of COPD patients, and the benefits persistent for 24 wk. The improvement in the 6MWT was more significant in COPD patients with a high blood EOS count.

Greek Guidelines for the Management of COPD, a Proposal of a Holistic Approach Based on the needs of the Greek Community

Despite that COPD remains one of the most common respiratory diseases worldwide, it can be managed effectively with certain treatments and, more importantly, be prevented by the early implementation of various measures. The pathology and pathophysiology of this disease continue to be studied, with new pharmacological and invasive therapies emerging. In this consensus paper, the Working Group of the Hellenic Thoracic Society aimed to consolidate the up-to-date information and new advances in the treatment of COPD. Local and international data on its prevalence are presented, with revised strategies on the diagnostic approach and the evaluation of risk assessment and disease severity classification. Emphasis is placed on the management and therapy of patients with COPD, covering both common principles, specialized modalities, and algorithms to distinguish between home care and the need for hospitalization. Although pharmacological treatment is commonly recognized in COPD, an integrative approach of pulmonary rehabilitation, physical activity, patient education, and self-assessment should be encountered for a comprehensive treatment, prevention of exacerbations, and increased quality of life in patients.

Fractional Exhaled Nitric Oxide (FeNO) in Patients with Stable Chronic Obstructive Pulmonary Disease: Short-Term Variability and Potential Clinical Implications

BACKGROUND

The use of fractional exhaled nitric oxide (FeNO) has been proposed for identifying and monitoring eosinophilic airway inflammation in chronic obstructive pulmonary disease (COPD). To explore the clinical utility of FeNO in COPD, we aimed to assess its short-term variability in a clinically stable COPD cohort.

METHODS

Consecutive COPD patients, formerly smokers, underwent FeNO assessment at the baseline and six time-points through serial sampling spaced 3 days apart.

RESULTS

A total of 41 patients (mean age 72.9, 87.8% males) showed a median baseline value of FeNO of 11.7 (8.0-16.8) ppb. A weak linear relationship was documented between baseline FeNO values and both eosinophil counts (r = 0.341, p = 0.029) and the percentage of eosinophils (r = 0.331, p = 0.034), confirmed in multiple linear regressions after adjusting for steroid use. The overall individual variability of FeNO between time-points was 3.90 (2.53-7.29) ppb, with no significant difference in the distribution of FeNO values measured at different time-points (p = 0.204). A total of 28 (68.3%) patients exhibited FeNO always below the 25 ppb cut-off at all determinations, while the remining 13 (31.7%) had at least one value above the established limit. Interestingly, none of these 13 participants had FeNO stably above 25 ppb, all showing at least one normal value during serial sampling. Compared to these patients with more fluctuating values, the 28 with stably normal FeNO only exhibited a significantly higher body weight (80.0 ± 18.2 kg vs. 69.0 ± 8.8 kg, p = 0.013) and body mass index (29.7 ± 6.5 kg/m2 vs. 25.9 ± 3.7 kg/m2, p = 0.026), confirmed in multiple logistic regressions after adjusting for major potential confounders.

CONCLUSIONS

A certain degree of FeNO variability, apparently unrelated to eosinophil counts but somehow influenced by body weight, must be considered in COPD patients. Further studies are needed to clarify whether this biomarker may be effectively used to plan more personalized pharmacological and rehabilitation strategies in this clinical setting.

Plasma Extracellular Vesicle miRNA Profiles Distinguish Chronic Obstructive Pulmonary Disease Exacerbations and Disease Severity

Purpose

Molecular biomarkers for chronic obstructive pulmonary disease (COPD) severity have been difficult to identify. We aimed to assess extracellular vesicle miRNAs’ potential as a blood biomarker in discriminating disease severity in participants with COPD.

Patients and Methods

Plasma extracellular vesicles (EVs) were obtained from two COPD cohorts (n = 20 during an exacerbation event, n = 20 during stable state), with varying disease severity (GOLD stages). The miRCURY LNA miRNA Serum/Plasma assay, specific to 179 targets, was used to evaluate EV miRNA expression. The miRNAs that were significantly dysregulated were further assessed for discriminatory power using ROC curve analysis, as well as their role in relevant biological pathways.

Results

One miRNA was significantly dysregulated between moderate GOLD participants compared to severe/very severe GOLD participants, with an AUC of 0.798, p = 0.01 for miR-374b-5p. Five miRNAs were significantly dysregulated between exacerbating and stable COPD participants, with miR-223-3p resulting in the highest AUC (0.755, p = 0.006) for a single miRNA, with a combination of three miRNAs (miR-92b-3p, miR-374a-5p and miR-106b-3p) providing the highest discriminatory power (AUC 0.820, p = 0.001). The “cytokine–cytokine receptor interaction” (hsa04060 pathway) was the most significant KEGG pathway enriched for three out of the five miRNAs associated with COPD exacerbations.

Conclusion

This initial small-scale study suggests that the bioactive cargo (miRNAs) in plasma EVs holds specific biological information for the severity of airflow obstruction and COPD exacerbations, warranting further investigation.

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.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT02546349.

Effects of inhaled corticosteroids (ICS) on lung microbiota and local immune response in long-term treatment of chronic obstructive pulmonary disease (COPD): utility of titration and therapeutic index

Administration of inhaled corticosteroids (ICS) is one of the most controversial issues in the treatment of stable chronic obstructive pulmonary disease (COPD). Associations between these drugs and increased incidence of severe pneumonia and other respiratory infections have already been reported in literature, as well as effects on the immune system and on the lung microbiota. ICS vary in their pharmacodynamic and pharmacokinetic properties, despite being widely considered therapeutically similar. The use of ICS requires, therefore, a deep knowledge of their pharmacokinetics and pharmacodynamics to obtain the maximum benefit and the least side effects. Defining new phenotypes-endotypes of COPD may lead to novel pharmacological and therapeutic scenarios while define the correct indications for prescription of ICS. Titration is certainly an important means by which these objectives can be achieved.

Genetic Associations and Architecture of Asthma-COPD Overlap

BACKGROUND

Some people have characteristics of both asthma and COPD (asthma-COPD overlap), and evidence suggests they experience worse outcomes than those with either condition alone.

RESEARCH QUESTION

What is the genetic architecture of asthma-COPD overlap, and do the determinants of risk for asthma-COPD overlap differ from those for COPD or asthma?

STUDY DESIGN AND METHODS

We conducted a genome-wide association study in 8,068 asthma-COPD overlap case subjects and 40,360 control subjects without asthma or COPD of European ancestry in UK Biobank (stage 1). We followed up promising signals (P < 5 × 10^-6) that remained associated in analyses comparing (1) asthma-COPD overlap vs asthma-only control subjects, and (2) asthma-COPD overlap vs COPD-only control subjects. These variants were analyzed in 12 independent cohorts (stage 2).

RESULTS

We selected 31 independent variants for further investigation in stage 2, and discovered eight novel signals (P < 5 × 10^-8) for asthma-COPD overlap (meta-analysis of stage 1 and 2 studies). These signals suggest a spectrum of shared genetic influences, some predominantly influencing asthma (FAM105A, GLB1, PHB, TSLP), others predominantly influencing fixed airflow obstruction (IL17RD, C5orf56, HLA-DQB1). One intergenic signal on chromosome 5 had not been previously associated with asthma, COPD, or lung function. Subgroup analyses suggested that associations at these eight signals were not driven by smoking or age at asthma diagnosis, and in phenome-wide scans, eosinophil counts, atopy, and asthma traits were prominent.

INTERPRETATION

We identified eight signals for asthma-COPD overlap, which may represent loci that predispose to type 2 inflammation, and serious long-term consequences of asthma.

Neuromedin U promotes human type 2 immune responses

Type 2 immunity mediates the immune responses against parasites and allergic stimuli. Evidence from studies of cell lines and animals implies that neuromedin U (NmU) acts as a pro-inflammatory mediator of type 2 inflammation. However, the role of NmU in human type 2 immunity remains unclear. Here we investigated the expression of NmU in human blood and airways, and the expression of NmU receptors by human immune cells in blood and lung tissue. We detected human NmU (hNmU-25) in blood and airways with higher concentrations in the latter. NmU receptor 1 (NmUR1) was expressed by most human immune cells with higher levels in type 2 cells including type 2 T helpers, type 2 cytotoxic T cells, group-2 innate lymphoid cells and eosinophils, and was upregulated in lung-resident and activated type 2 cells. We also assessed the effects of NmU in these cells. hNmU-25 elicited type 2 cytokine production by type 2 lymphocytes and induced cell migration, including eosinophils. hNmU-25 also enhanced the type 2 immune response to other stimuli, particularly prostaglandin D2. These results indicate that NmU could contribute to the pathogenic processes of type 2 immunity-mediated diseases in humans via its pro-inflammatory effects on type 2 lymphocytes and eosinophils.

Chronic obstructive pulmonary disease and atherosclerosis: common mechanisms and novel therapeutics

Chronic obstructive pulmonary disease (COPD) and atherosclerosis are chronic irreversible diseases, that share a number of common causative factors including cigarette smoking. Atherosclerosis drastically impairs blood flow and oxygen availability to tissues, leading to life-threatening outcomes including myocardial infarction (MI) and stroke. Patients with COPD are most likely to die as a result of a cardiovascular event, with 30% of all COPD-related deaths being attributed to cardiovascular disease (CVD). Both atherosclerosis and COPD involve significant local (i.e. lung, vasculature) and systemic inflammation and oxidative stress, of which current pharmacological treatments have limited efficacy, hence the urgency for the development of novel life-saving therapeutics. Currently these diseases must be treated individually, with no therapies available that can effectively reduce the likelihood of comorbid CVD other than cessation of cigarette smoking. In this review, the important mechanisms that drive atherosclerosis and CVD in people with COPD are explained and we propose that modulation of both the oxidative stress and the inflammatory burden will provide a novel therapeutic strategy to treat both the pulmonary and systemic manifestations related to these diseases.

From DREAM to REALITI-A and beyond: Mepolizumab for the treatment of eosinophil-driven diseases

Effective treatment of inflammatory diseases is often challenging owing to their heterogeneous pathophysiology. Understanding of the underlying disease mechanisms is improving and it is now clear that eosinophils play a complex pathophysiological role in a broad range of type 2 inflammatory diseases. Standard of care for these conditions often still includes oral corticosteroids (OCS) and/or cytotoxic immune therapies, which are associated with debilitating side effects. Selective, biological eosinophil‐reducing agents provide treatment options that improve clinical symptoms associated with eosinophilic inflammation and reduce OCS use. Mepolizumab is a humanized monoclonal antibody that binds to and neutralizes interleukin‐5, the major cytokine involved in eosinophil proliferation, activation, and survival. Mepolizumab is approved for the treatment of severe eosinophilic asthma, eosinophilic granulomatosis with polyangiitis and hypereosinophilic syndrome. Additionally, the efficacy of add‐on mepolizumab has been observed in patients with severe chronic rhinosinusitis with nasal polyposis and chronic obstructive pulmonary disease with an eosinophilic phenotype. Here, we review the development, approval, and real‐world effectiveness of mepolizumab for the treatment of patients with severe eosinophilic asthma, from the DREAM to REALITI‐A studies, and describe how knowledge from this journey extended to the use of mepolizumab and other biologics across a broad spectrum of eosinophilic diseases.

The use of treatable traits to address COPD complexity and heterogeneity and to inform the care

COPD is complex and heterogeneous with respect to its aetiology, clinical presentation, phenotypes and biological mechanisms. Despite this, COPD is still diagnosed and treated according to simple clinical measures, including airflow limitation, symptoms and exacerbation frequency, leading to failure to recognise the disease's heterogeneity and/or to provide targeted interventions. COPD continues to have a very large burden of disease with suboptimal outcomes for people with the disease, including frequent hospitalisation with exacerbations, rapid lung function decline, multimorbidity and death from respiratory failure. In light of this, there have been increasing calls for a renewed taxonomy with better characterisation of COPD phenotypes and endotypes. This would allow the unravelling of COPD's complexity and heterogeneity, the implementation of targeted interventions and improved patient outcomes. The treatable traits strategy is a proposed vehicle for the implementation of precision medicine in chronic airway diseases. In this review, in addition to summarising the key knowledge on the heterogeneity of COPD, we refer to the existing evidence pertaining to the treatable traits strategy as applied in COPD and discuss implementation in different settings.

COPD is a heterogeneous clinical syndrome, which requires deconstruction of its individual components to facilitate targeted treatment and improve individual patient outcomes. 
https://bit.ly/2YXWgHN

Long‐term oxygen treatment need is less frequent in eosinophilic COPD patients

Introduction

Methods

Results

Conclusion

The prognostic factors of in-hospital death among patients with pneumonic COPD acute exacerbation

BACKGROUND

Pneumonic acute exacerbation of chronic obstructive pulmonary disease (COPD-AE) is associated with worse outcomes compared with non-pneumonic COPD-AE. We aimed to explore prognostic factors among patients with pneumonic COPD-AE.

METHODS

This multicentered retrospective cohort study was conducted across five hospitals in Japan. Hospitalized patients ≥40 years of age with pneumonic COPD-AE who were administered systemic corticosteroids during hospitalization were included. Patients with other causes of respiratory failure, daily systemic steroid users, and patients who were not treated with systemic steroids were excluded. Based on existing clinical prediction models, the following potential prognostic factors were selected in advance: age, blood eosinophil count, blood urea nitrogen, respiratory rate, diastolic blood pressure, and altered mental status. Multivariate logistic regression was conducted to determine the association between potential prognostic factors and in-hospital death.

RESULTS

After excluding 897 patients based on the exclusion criteria, 669 patients with pneumonic COPD-AE who were administered systemic corticosteroids were included. The in-hospital mortality rate was 5.1%. Altered mental status was associated with mortality (odds ratio, 4.47; 95% confidence intervals, 2.00 to 10.00), and eosinophilia was associated with a lower risk of mortality (odds ratio, 0.19; 95% confidence intervals: 0.06 to 0.56).

CONCLUSIONS

Altered mental status may be a prognostic factor for in-hospital death among patients with pneumonic COPD-AE who were administered systemic corticosteroids. Moreover, eosinophilia may be a prognostic factor for lower in-hospital mortality rate among these patients.

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.

Asthma COPD overlap: Insights into cellular and molecular mechanisms

Although there is still no consensus on the definition of Asthma-COPD Overlap (ACO), it is generally accepted that some patients with airway disease have features of both asthma and COPD. Just as its constituents, ACO consists of different phenotypes, possibly depending on the predominance of the underlying asthma or COPD-associated pathophysiological mechanisms. The clinical picture is influenced by the development of airway inflammatory processes either eosinophilic, neutrophilic or mixed, in addition to glandular changes leading to mucus hypersecretion and a variety of other airway structural changes. Although animal models have exposed how smoking-related changes can interact with those observed in asthma, much remains to be known about their interactions in humans and the additional modulating effects of environmental exposures. There is currently no solid evidence to establish the optimal treatment of ACO but it should understandably include an avoidance of environmental triggers such as smoking and relevant allergens. The recognition and targeting of "treatable traits" following phenotyping is a pragmatic approach to select the optimal pharmacological treatment for ACO, although an association of inhaled corticosteroids and bronchodilators is always required in these patients. This association acts both as an anti-inflammatory treatment for the asthma component and as a functional antagonist for the airway remodeling features. Research should be promoted on well phenotyped subgroups of ACO patients to determine their optimal management.

Moving towards a Treatable Traits model of care for the management of obstructive airways diseases

Asthma and chronic obstructive pulmonary disease (COPD) are two prevalent chronic airways diseases. Both are complex and heterogeneous. Traditionally, clinical guidelines have advocated a stepwise approach to pharmacotherapy of asthma and COPD, but there is increasing realization that both require a more personalized and precise management approach. To this end, a management strategy based on the so-called Treatable Traits has been proposed. Emerging evidence suggests that this model improves relevant outcomes in patients with chronic airway diseases but further research is needed to guide implementation. This review discusses the challenges, opportunities, and hurdles that its implementation will have to face.

Biomarkers in Chronic Obstructive Pulmonary Disease: Emerging Roles of Eosinophils and Procalcitonin

Antibiotics can improve the prognosis in patients with exacerbation of chronic obstructive pulmonary disease. However, the overuse of antibiotics can carry serious adverse effects for patients (gastrointestinal infections) and for society (bacterial resistance). Likewise, systemic corticosteroids may also help these patients, but also carries severe adverse effects like osteoporosis, muscle loss, and diabetes, in many patients. Whenever safe methods exist to reduce these two treatment modalities, they should be implemented. The blood biomarkers procalcitonin and the fraction of leukocytes known as eosinophil granulocytes have been proven in randomized controlled trials (RCTs), to effectively, significantly, and substantially assist in reducing the use of these two potent, yet toxic medication types. In this review, the background and main clinical results are discussed, explaining the rationale for biomarker-guided clinical decisions. Also, the main expected effects, their sizes, and importantly the limitations to such a strategy are described. Clinical evidence is prioritized with main weight on RCTs and meta-analyses of these and regarding outcomes, and focus is set on the safety of such a biomarker-guided strategy, as well as the effects on medicine reduction. In an epoch of increasing demands to physicians from patients and politicians to cure and reduce symptoms, the Hippocratic phrase of "primum non nocere" or "first, do no harm" seems more than ever of contemporary importance.

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

Introduction

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

Methods

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

Results

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

Discussion

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

Interleukin-13: A pivotal target against influenza-induced exacerbation of chronic lung diseases

Non-communicable, chronic respiratory diseases (CRDs) affect millions of individuals worldwide. The course of these CRDs (asthma, chronic obstructive pulmonary disease, and cystic fibrosis) are often punctuated by microbial infections that may result in hospitalization and are associated with increased risk of morbidity and mortality, as well as reduced quality of life. Interleukin-13 (IL-13) is a key protein that regulates airway inflammation and mucus hypersecretion. There has been much interest in IL-13 from the last two decades. This cytokine is believed to play a decisive role in the exacerbation of inflammation during the course of viral infections, especially, in those with pre-existing CRDs. Here, we discuss the common viral infections in CRDs, as well as the potential role that IL-13 plays in the virus-induced disease pathogenesis of CRDs. We also discuss, in detail, the immune-modulation potential of IL-13 that could be translated to in-depth studies to develop IL-13-based therapeutic entities.

Pathophysiology of Bronchiectasis

Bronchiectasis is a complex, heterogeneous disorder defined by both a radiological abnormality of permanent bronchial dilatation and a clinical syndrome. There are multiple underlying causes including severe infections, mycobacterial disease, autoimmune conditions, hypersensitivity disorders, and genetic conditions. The pathophysiology of disease is understood in terms of interdependent concepts of chronic infection, inflammation, impaired mucociliary clearance, and structural lung damage. Neutrophilic inflammation is characteristic of the disease, with elevated levels of harmful proteases such as neutrophil elastase associated with worse outcomes. Recent data show that neutrophil extracellular trap formation may be the key mechanism leading to protease release and severe bronchiectasis. Despite the dominant of neutrophilic disease, eosinophilic subtypes are recognized and may require specific treatments. Neutrophilic inflammation is associated with elevated bacterial loads and chronic infection with organisms such as Pseudomonas aeruginosa. Loss of diversity of the normal lung microbiota and dominance of proteobacteria such as Pseudomonas and Haemophilus are features of severe bronchiectasis and link to poor outcomes. Ciliary dysfunction is also a key feature, exemplified by the rare genetic syndrome of primary ciliary dyskinesia. Mucus symptoms arise through goblet cell hyperplasia and metaplasia and reduced ciliary function through dyskinesia and loss of ciliated cells. The contribution of chronic inflammation, infection, and mucus obstruction leads to progressive structural lung damage. The heterogeneity of the disease is the most challenging aspect of management. An understanding of the pathophysiology of disease and their biomarkers can help to guide personalized medicine approaches utilizing the concept of "treatable traits."

Comprehensive Care Management in Conjunction with Sputum Cytometry-Guided Pharmacotherapy in a Post-Discharge Clinic for Patients with COPD

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are amongst the most common reasons for hospital admission, and recurrent episodes occur frequently. Comprehensive care management (CCM) strategies have modest effect in preventing re-admissions. The objectives of this study were to examine the utility of optimizing anti-inflammatory therapy guided by sputum cytometry in the post-hospitalization setting, and to assess the feasibility and effectiveness of a clinic combining CCM and sputum-guided therapy. This is an observational study examining patients who received open-label CCM and sputum cytometry-guided pharmacotherapy in a COPD post-discharge clinic. Referral was based on high risk for readmission after hospitalization for AECOPD. The primary outcome was the change in COPD-related healthcare utilization before and after Visit 1, and this was analyzed with a mixed-effects negative binomial model controlling for age, number of follow-up clinic visits, pack years, current smoking and FEV₁. Of 138 patients referred to the clinic, 73% attended at least one visit. Mean FEV₁ was 42.8 (19.3) % predicted. Of the patients attending clinic, 42.6% produced an adequate sputum sample, and 32.7% had an abnormal sputum. By individual, infectious bronchitis was the most common (25.7%), followed by eosinophilic bronchitis (13.9%). Comparing the 6-months prior to and after the first clinic visit, there was a lower incidence rate ratio after visit 1 for COPD-related healthcare utilization (0.26 (95%CI 0.22,0.33; p < 0.001)). A COPD post-discharge clinic combining sputum-guided treatment and CCM was feasible and associated with a nearly 75% reduction in the incidence of COPD-related healthcare utilization.

Molecular markers of type 2 airway inflammation are similar between eosinophilic severe asthma and eosinophilic chronic obstructive pulmonary disease

BACKGROUND

Airway and systemic eosinophilia are important treatable traits in both severe asthma and COPD. The molecular basis of eosinophilia in COPD is poorly understood but could involve type 2 cytokines (IL5, IL13) and prostaglandin D₂ (PGD₂ ).

METHODS

This study included non-obstructive airways disease (OAD) controls (n = 19), a COPD cohort (n = 96) and a severe asthma cohort (n = 84). Demographics, exacerbation history, disease impact (SGRQ) and spirometry were assessed. Participants were categorized as eosinophilic using either sputum eosinophil proportion (≥3%) or blood eosinophil count (≥300/μL). Sputum type 2 inflammatory measures included PGD₂ by ELISA and gene expression (qPCR) of IL5, IL13 and the haematopoietic PGD₂ synthase (HPGDS).

RESULTS

Type 2 markers did not differ across groups except HPGDS mRNA which was highest in non-OAD controls and lowest in COPD. IL5 and IL13 mRNA and PGD₂ levels were significantly increased in eosinophilic vs non-eosinophilic severe asthma but did not differ between eosinophilic COPD and eosinophilic severe asthma or non-eosinophilic COPD. HPGDS expression was higher in eosinophilic severe asthma compared with eosinophilic COPD. Results were similar using sputum or blood eosinophil cut-offs. Sputum IL5 and IL13 were highly intercorrelated in severe asthma (r = 0.907, p < 0.001) and COPD (r = 0.824, p < 0.001), were moderately correlated with sputum eosinophils in severe asthma (IL5 r = 0.440, p < 0.001; IL13 r = 0.428, p < 0.001) and were weakly correlated in COPD (IL5 r = 0.245, p < 0.05; IL13 r = 0.317, p < 0.05).

CONCLUSIONS

Molecular markers of type 2 airway inflammation do not differ between eosinophilic asthma and eosinophilic COPD; however, the relationship between eosinophilia and type 2 airway markers appears weaker in COPD than in severe asthma.

Unravelling the mechanisms driving multimorbidity in COPD to develop holistic approaches to patient-centred care

COPD is a major cause of morbidity and mortality worldwide. Multimorbidity is common in COPD patients and a key modifiable factor, which requires timely identification and targeted holistic management strategies to improve outcomes and reduce the burden of disease.We discuss the use of integrative approaches, such as cluster analysis and network-based theory, to understand the common and novel pathobiological mechanisms underlying COPD and comorbid disease, which are likely to be key to informing new management strategies.Furthermore, we discuss the current understanding of mechanistic drivers to multimorbidity in COPD, including hypotheses such as multimorbidity as a result of shared common exposure to noxious stimuli (e.g. tobacco smoke), or as a consequence of loss of function following the development of pulmonary disease. In addition, we explore the links to pulmonary disease processes such as systemic overspill of pulmonary inflammation, immune cell priming within the inflamed COPD lung and targeted messengers such as extracellular vesicles as a result of local damage as a cause for multimorbidity in COPD.Finally, we focus on current and new management strategies which may target these underlying mechanisms, with the aim of holistic, patient-centred treatment rather than single disease management.

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.

Targeted therapy in eosinophilic chronic obstructive pulmonary disease

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

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

Epidemiology and issues of NIV-treated AECOPD patients with hypercapnic respiratory failure in Shanghai: A multicentre retrospective survey

OBJECTIVE

To investigate the epidemiology, clinical features, treatment and outcome of Noninvasive ventilation (NIV)-treated acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients in secondary hospitals of Shanghai.

METHOD

Relying on Shanghai alliances for respiratory diseases, a retrospective observational study was performed in 34 secondary hospitals of Shanghai. The AECOPD patients treated with NIV and admitted to the respiratory department or respiratory intensive care unit were recruited between December 1, 2016, and November 30, 2017.

RESULTS

There were 555 patients finally recruited in this study. The age was 75.8 ± 9.6 years old and 380 patients (68.5%) were male. 70.5% of all patients had respiratory acidosis (pH <7.35). 55.3% of all patients received nebulised bronchodilator and 77.7% were treated with systemic or inhaled corticosteroids during hospitalisation. 525 patients (94.6%) recovered successfully and the mortality was 3.2%. The hospitalisation was 15.3 ± 6.7 days and hospital expenses were 22 911 ± 13 595 RMB. Inadequate and nonstandard drug treatments were the most important problems during management.

CONCLUSION

The NIV can be successfully used for AECOP patients in local hospitals of Shanghai, but accompanied by high costs and long hospital stays. However, the treatments for exacerbation and stable COPD patients are still insufficient.

Blood eosinophils on hospital admission for COPD exacerbation do not predict the recurrence of moderate and severe relapses

Background and objective

The relationship between hospitalisation with an eosinophilic acute exacerbation of COPD (AE-COPD) and future relapses is unclear. We aimed to explore this association by following 152 patients for 12 months after hospital discharge or until their first moderate or severe flare-up.

Methods

Patients hospitalised with AE-COPD were divided into eosinophilic and non-eosinophilic groups based on full blood count results on admission. All patients were treated with a course of systemic corticosteroid. The Cox proportional hazards model was used to study the association with the time to first re-exacerbation; a generalised linear regression model was applied to identify clinical variables related to the recurrence of relapses.

Results

We did not find a difference in the time to the next moderate or severe exacerbation between the eosinophilic (≥2% of total leukocytes and/or ≥200 eosinophils·µL⁻¹, n=51, median (interquartile range): 21 (10–36) weeks) and non-eosinophilic groups (n=101, 17 (9–36) weeks, log-rank test: p=0.63). No association was found when other cut-off values (≥3% of total leukocytes and/or ≥300 eosinophils·µL⁻¹) were used for the eosinophilic phenotype. However, the higher number of past severe exacerbations, a lower forced expiratory volume in 1 s (FEV₁) at discharge and higher pack-years were related to shorter exacerbation-free time. According to a subgroup analysis (n=73), 48.1% of patients with initial eosinophilic exacerbations had non-eosinophilic relapses on readmission.

Conclusions

Our data do not support an increased risk of earlier recurring moderate or severe relapses in patients hospitalised with eosinophilic exacerbations of COPD. Eosinophilic severe exacerbations present a variable phenotype.

Shorter time to the next relapse after severe COPD exacerbation is related to the number of prior hospitalisations, smoking history and more severe airflow limitation. Blood eosinophils are not predictive of the recurrence of moderate or severe relapses.https://bit.ly/2VkbBNC

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.

Hemopexin: A Novel Anti-inflammatory Marker for Distinguishing COPD From Asthma

Purpose

Systemic inflammatory biomarkers can improve diagnosis and assessment of chronic obstructive pulmonary disease (COPD) and asthma. We aimed to validate an airway disease biomarker panel of 4 systemic inflammatory biomarkers, α2-macroglobulin, ceruloplasmin, haptoglobin and hemopexin, to establish their relationship to airway disease diagnosis and inflammatory phenotypes and to identify an optimized biomarker panel for disease differentiation.

Methods

Participants with COPD or asthma were classified by inflammatory phenotypes. Immunoassay methods were used to measure levels of validation biomarkers in the sera of participants with disease and non-respiratory disease controls. Markers were analyzed individually and in combination for disease differentiation and compared to established biomarkers (C-reactive protein, interleukin-6, and white blood cell/blood eosinophil count).

Results

The study population comprised of 141 COPD, 127 severe asthma, 54 mild-moderate asthma and 71 control participants. Significant differences in ceruloplasmin, haptoglobin and hemopexin levels between disease groups and between systemic inflammatory phenotypes were observed. However, no differences were found between airway inflammatory phenotypes. Hemopexin was the best performing individual biomarker and could diagnose COPD versus control participants (area under the curve [AUC], 98.3%; 95% confidence interval [CI], 96.7%–99.9%) and differentiate COPD from asthmatic participants (AUC, 97.0%; 95% CI, 95.4%–98.6%), outperforming established biomarkers. A biomarker panel, including hemopexin, haptoglobin and other established biomarkers, could diagnose asthma versus control participants (AUC, 87.5%; 95% CI, 82.8%–92.2%).

Conclusions

Hemopexin can be a novel biomarker with superior diagnostic ability in differentiating COPD and asthma. We propose an anti-inflammatory axis between the airways and systemic circulation, in which hemopexin is a protective component in airway disease.

Pharmacotherapy of chronic obstructive pulmonary disease: Therapeutic considerations with a focus on inhaled corticosteroids

International and national guidelines on chronic obstructive pulmonary disease (COPD) emphasise bronchodilators as first-line therapy. However, in considering them the 'foundation' of treatment, attention has shifted from the fact that COPD is fundamentally an inflammatory disease. The mainstay ought to be anti-inflammatory medication, and inhaled corticosteroids (ICS) are the best agents we have presently. There was initial scepticism about their role, but ICS were subsequently shown to have numerous anti-inflammatory effects. They are synergistic with bronchodilators at a molecular and clinical level and unequivocally improve dyspnoea, quality of life, exacerbation frequency and, more recently, mortality. These benefits are most apparent in the COPD eosinophilic phenotype. These beneficial effects have been met with some reservations because of the predisposition to pneumonia of ICS. This must be seen in context: over 90% of COPD patients in all clinical trials do not get pneumonia. The fact that patients with COPD are predisposed to pneumonia because of the disease itself is disregarded; this is a crucial omission as this constitutes the baseline incidence of about 3%. When one allows for this, then in the clinical reports, the excess risk of pneumonia ranges from zero to a maximum of 3%. Equally, some of the systemic effects attributed to ICS fail to appreciate that the disease, smoking and older age are risk factors in themselves, and ICS do not aggravate these. Chronic obstructive pulmonary disease has considerable impact on respiratory reserve and is associated with increasing morbidity; optimal outcomes are best achieved with long-acting bronchodilators and ICS co-prescription.

Anti-IL-5 therapies for chronic obstructive pulmonary disease

BACKGROUND

Exacerbations of chronic obstructive pulmonary disease (COPD) are a major cause of hospital admissions, disease-related morbidity and mortality. COPD is a heterogeneous disease with distinct inflammatory phenotypes, including eosinophilia, which may drive acute exacerbations in a subgroup of patients. Monoclonal antibodies targeting interleukin 5 (IL-5) or its receptor (IL-5R) have a role in the care of people with severe eosinophilic asthma, and may similarly provide therapeutic benefit for people with COPD of eosinophilic phenotype.

OBJECTIVES

To assess the efficacy and safety of monoclonal antibody therapies targeting IL-5 signalling (anti-IL-5 or anti-IL-5Rα) compared with placebo in the treatment of adults with COPD.

SEARCH METHODS

We searched the Cochrane Airways Trials Register, CENTRAL, MEDLINE, Embase, clinical trials registries, manufacturers' websites, and reference lists of included studies. Our most recent search was 23 September 2020.

SELECTION CRITERIA

We included randomised controlled trials comparing anti-IL-5 therapy with placebo in adults with COPD.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and analysed outcomes using a random-effects model.The primary outcomes were exacerbations requiring antibiotics or oral steroids, hospitalisations due to exacerbation of COPD, serious adverse events, and quality of life. We used standard methods expected by Cochrane. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

Six studies involving a total of 5542 participants met our inclusion criteria. Three studies used mepolizumab (1530 participants), and three used benralizumab (4012 participants). The studies were on people with COPD, which was similarly defined with a documented history of COPD for at least one year. We deemed the risk of bias to be generally low, with all studies contributing data of robust methodology. Mepolizumab 100 mg reduces the rate of moderate or severe exacerbations by 19% in those with an eosinophil count of at least 150/μL (rate ratio (RR) 0.81, 95% confidence interval (CI) 0.71 to 0.93; participants = 911; studies = 2, high-certainty evidence). When participants with lower eosinophils are included, mepolizumab 100 mg probably reduces the exacerbation rate by 8% (RR 0.92, 95% CI 0.82 to 1.03; participants = 1285; studies = 2, moderate-certainty evidence). Mepolizumab 300 mg probably reduces the rate of exacerbations by 14% in participants all of whom had raised eosinophils (RR 0.86, 95% CI 0.70 to 1.06; participants = 451; studies = 1, moderate-certainty evidence); the evidence was uncertain for a single small study of mepolizumab 750 mg. In participants with high eosinophils, mepolizumab probably reduces the rate of hospitalisation by 10% (100 mg, RR 0.90, 95% CI 0.65 to 1.24; participants = 911; studies = 2, moderate-certainty evidence) and 17% (300 mg, RR 0.83, 95% CI 0.51 to 1.35; participants = 451; studies = 1, moderate-certainty evidence). Mepolizumab 100 mg increases the time to first moderate or severe exacerbation compared to the placebo group, in people with the eosinophilic phenotype (hazard ratio (HR) 0.78, 95% CI 0.66 to 0.92; participants = 981; studies 2, high-certainty evidence). When participants with lower eosinophils were included this difference was smaller and less certain (HR 0.87, 95% CI 0.75 to 1.0; participants = 1285; studies 2, moderate-certainty evidence). Mepolizumab 300 mg probably increases the time to first moderate or severe exacerbation in participants who all had eosinophilic phenotype (HR 0.77, 95% CI 0.60 to 0.99; participants = 451; studies = 1, moderate-certainty evidence). Benralizumab 100 mg reduces the rate of severe exacerbations requiring hospitalisation in those with an eosinophil count of at least 220/μL (RR 0.63, 95% CI 0.49 to 0.81; participants = 1512; studies = 2, high-certainty evidence). Benralizumab 10 mg probably reduces the rate of severe exacerbations requiring hospitalisation in those with an eosinophil count of at least 220/μL (RR 0.68, 95% CI 0.49 to 0.94; participants = 765; studies = 1, moderate-certainty evidence). There was probably little or no difference between the intervention and placebo for quality of life measures. Where there were differences the mean difference fell below the pre-specified minimum clinically significant difference. Treatment with mepolizumab and benralizumab appeared to be safe. All pooled analyses showed that there was probably little or no difference in serious adverse events, adverse events, or side effects between the use of a monoclonal antibody therapy compared to placebo.

AUTHORS' CONCLUSIONS

We found that mepolizumab and benralizumab probably reduce the rate of moderate and severe exacerbations in the highly selected group of people who have both COPD and higher levels of blood eosinophils. This highlights the importance of disease phenotyping in COPD, and may play a role in the personalised treatment strategy in disease management. Further research is needed to elucidate the role of monoclonal antibodies in the management of COPD in clinical practice. In particular, it is not clear whether there is a threshold blood eosinophil level above which these drugs may be effective. Studies including cost effectiveness analysis may be beneficial given the high cost of these therapies, to support use if appropriate.

The Role of Electronic Noses in Phenotyping Patients with Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a common progressive disorder of the respiratory system which is currently the third leading cause of death worldwide. Exhaled breath analysis is a non-invasive method to study lung diseases, and electronic noses have been extensively used in breath research. Studies with electronic noses have proved that the pattern of exhaled volatile organic compounds is different in COPD. More recent investigations have reported that electronic noses could potentially distinguish different endotypes (i.e., neutrophilic vs. eosinophilic) and are able to detect microorganisms in the airways responsible for exacerbations. This article will review the published literature on electronic noses and COPD and help in identifying methodological, physiological, and disease-related factors which could affect the results.

Dual Bronchodilator in the Era of Triple Therapy

Pharmacological medications used for the treatment of COPD patients have increased significantly. Long-acting bronchodilators have been recognized as the mainstay of the treatment of stable COPD, while ICS are usually added in patients with COPD who experience exacerbations, despite bronchodilator treatment. In the latest years, several studies have been published showing the beneficial effect of adding ICS on dual bronchodilation in patients suffering from more severe disease comparing triple therapy with several therapeutic regiments including dual bronchodilation and providing a message that this triple therapy might be more appropriate for COPD patients. However, not all COPD patients have a desirable response to ICS treatment while long-term ICS use in COPD is associated with several side effects. In this report, we aimed to provide a review of the current knowledge on the importance of dual bronchodilation on COPD patients and to compare its use with triple therapy, by covering a wide spectrum of topics. Finally, we propose an algorithm on performing treatment step up from dual bronchodilation to triple therapy and step down from triple to double bronchodilation considering the current evidence.

Chronic obstructive pulmonary disease phenotypes: imprint on pharmacological and non-pharmacological therapy

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease associated with significant morbidity and mortality. Over the past few years, there has been cumulating interest in describing this heterogeneity and using this information to group patients into different COPD phenotypes. The term phenotype is defined as single or combination of disease attributes that describe differences between individuals with COPD as they relate to clinically meaningful outcomes. It describes also the physical appearance or biochemical characteristics which result from the genotype-environment interaction. Furthermore, it clearly identifies subgroups with a significant impact in the prognosis. Recently, approaches to COPD phenotyping have been significantly enhanced in tandem with developments in understanding the disease’s various pathological, clinical and genetic features. This knowledge inspired the researchers to investigate more tailored therapeutic strategies that could not only give a more potent effect but also help to avoid the traditional therapy’s undesirable side effects. Eventually, it could be said that the phenotypic approach to COPD in the last decade had a huge impact on daily practice and management delivered to COPD patients. In this review, we highlight the impact of pharmacological and non-pharmacological treatment options on COPD outcomes, using a personalized treatment strategy based on different phenotypes.

Eosinophilic inflammation in COPD: from an inflammatory marker to a treatable trait

The heterogeneity of chronic obstructive pulmonary disease (COPD) creates many diagnostic, prognostic, treatment and management challenges, as the pathogenesis of COPD is highly complex and the underlying cellular and molecular mechanisms remain poorly understood. A reliable, easy-to-measure, clinically relevant biomarker would be invaluable for improving outcomes for patients. International and national guidance for COPD suggests using blood eosinophil counts as a biomarker to help estimate likely responsiveness to inhaled corticosteroids (ICS) and, potentially, to aid effective management strategies. However, with the mechanism underlying the association between higher eosinophil levels and ICS effect unknown, use of the blood eosinophil count in COPD continues to be widely debated by the respiratory community.

Two international meetings involving respiratory medicine specialists, immunologists and primary and secondary care clinicians were held in November 2018 and March 2019, facilitated and funded by GlaxoSmithKline plc. The aims of these meetings were to explore the role of eosinophils in the disease processes of COPD and as prognostic and diagnostic markers, and to identify areas of deficient knowledge that warrant further research. The consensus views of the attendees on key topics, contextualised with current literature, are summarised in this review article, with the aim of aiding ongoing research into the disease processes of COPD and the development of biomarkers to aid clinical management.

Under certain conditions, eosinophils can be recruited to the lung, and increasing evidence supports a role for eosinophilic inflammation in some patients with COPD. Infiltration of eosinophils across the bronchial vascular epithelium into the airways is promoted by the actions of immunoregulatory cells, cytokines and chemokines, where eosinophil-mediated inflammation is driven by the release of proinflammatory mediators.

Multiple studies and two meta-analyses suggest peripheral blood eosinophils may correlate positively with an increased likelihood of exacerbation reduction benefits of ICS in COPD. The studies, however, vary in design and duration and by which eosinophil levels are viewed as predictive of an ICS response. Generally, the response was seen when eosinophil levels were 100–300 cells/µL (or higher), levels which are traditionally viewed within the normal range. Some success with interleukin-5-targeted therapy suggests that the eosinophilic phenotype may be a treatable trait.

The use of biomarkers could help to stratify treatment for COPD—the goal of which is to improve patient outcomes. Some evidence supports eosinophils as a potential biomarker of a treatable trait in COPD, though it is still lacking and research is ongoing. A unified consensus and a practical, accessible and affordable method of utilising any biomarker for COPD was thought to be of most importance. Challenges around its utilisation may include presenting a clear and pragmatic rationale for biomarker-driven therapy, guidance on ICS withdrawal between primary and secondary care and a lack of financial incentives supporting broad application in clinical practice. Future treatments should, perhaps, be more targeted rather than assuming the primary disease label (COPD or asthma) will define treatment response.