Eosinophils in COPD Exacerbations Are Associated With Increased Readmissions

Characteristics, treatments, in-hospital and long-term outcomes among inpatients with acute exacerbation of chronic obstructive pulmonary disease in China: sex differences in a large cohort study

BACKGROUND

Data related to the characteristics, treatments and clinical outcomes of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) patients in China are limited, and sex differences are still a neglected topic.

METHODS

The patients hospitalized for AECOPD were prospectively enrolled from ten medical centers in China between September 2017 and July 2021. Patients from some centers received follow-up for 3 years. Data regarding the characteristics, treatments and in-hospital and long-term clinical outcomes from male and female AECOPD patients included in the cohort were analyzed and compared.

RESULTS

In total, 14,007 patients with AECOPD were included in the study, and 11,020 (78.7%) were males. Compared with males, female patients were older (74.02 ± 10.79 vs. 71.86 ± 10.23 years, P < 0.001), and had more comorbidities (2.22 ± 1.64 vs. 1.73 ± 1.56, P < 0.001), a higher frequency of altered mental status (5.0% vs. 2.9%, P < 0.001), lower diastolic blood pressure (78.04 ± 12.96 vs. 79.04 ± 12.47 mmHg, P < 0.001). In addition, there were also significant sex differences in a range of laboratory and radiographic findings. Females were more likely to receive antibiotics, high levels of respiratory support and ICU admission than males. The in-hospital and 3-year mortality were not significantly different between males and females (1.4% vs. 1.5%, P = 0.711; 35.3% vs. 31.4%, P = 0.058), while female smokers with AECOPD had higher in-hospital mortality than male smokers (3.3% vs. 1.2%, P = 0.002) and male smokers exhibited a trend toward higher 3-year mortality compared to female smokers (40.7% vs. 33.1%, P = 0.146).

CONCLUSIONS

In AECOPD inpatients, females and males had similar in-hospital and long-term survival despite some sex differences in clinical characteristics and treatments, but female smokers had significantly worse in-hospital outcomes than male smokers.

CLINICAL TRIAL REGISTRATION

Retrospectively registered, registration number is ChiCTR2100044625, date of registration 21/03/2021. URL: http://www.chictr.org.cn/showproj.aspx?proj=121626 .

Platelet count and platelet-to-lymphocyte ratio at the onset of a severe COPD exacerbation are unrelated to the time till the next moderate or severe relapse

PURPOSE

Acute exacerbations (AE) are severe complications of chronic obstructive pulmonary disease (COPD); however, the need for biomarkers which predict them is still unmet. High platelet count (PLC) and platelet-to-lymphocyte ratio (PLR) are associated with higher mortality in patients with COPD. We investigated if PLC and PLR at the onset of a severe AE could predict the time of the next relapse.

METHODS

In a prospective observational cohort study, data of 152 patients hospitalized with AECOPD were collected, and patients were divided into PLC-low (<239 ​× ​109/L, n ​= ​51), PLC-medium (239-297 ​× ​109/L, n ​= ​51) and PLC-high (>297 ​× ​109/L, n ​= ​50) or PLR-low (<147, N ​= ​51), PLR-medium (147-295, n ​= ​51) and PLR high (>295, n ​= ​50) groups based on PLC and PLR tertiles using admission laboratory results. Clinical characteristics and the time to the next severe or moderate AE within 52 weeks were compared among subgroups using log-rank test.

RESULTS

PLC and PLR tertiles did not differ in clinical characteristics or the time till the next AE (p ​> ​0.05). PLC and PLR showed a direct weak correlation to neutrophil count (Pearson r ​= ​0.26, p ​< ​0.01 and r ​= ​0.20, p ​= ​0.01) and PLC also demonstrated a weak relationship to white blood cell counts (Pearson r ​= ​0.29, p ​< ​0.001). However, PLR presented an inverse relationship to monocyte and eosinophil counts (r ​= ​-0.32, p ​< ​0.001 and r ​= ​-0.17, p ​= ​0.03).

CONCLUSION

PLC and PLR do not predict the time till the next relapse; however, they may reflect on neutrophilic inflammatory response during an exacerbation of COPD.

The association between blood eosinophils and clinical outcome of acute exacerbations of chronic obstructive pulmonary disease: A systematic review and meta-analysis

OBJECTIVES

Studies have shown an association between eosinophilia and clinical outcomes in acute exacerbation of chronic obstructive pulmonary disease (AECOPD). However, contradictory findings exist. Our study aims to systematically evaluate the association between elevated peripheral blood eosinophils and clinical outcome of patients with AECOPD.

METHODS

An electronic search was conducted for relevant studies published from database inception to February 28, 2023, on PubMed, EMBASE, Cochrane Library, and Web of Science. The analysis covered studies on the correlation between EOS AECOPD and mortality, hospital stay duration, readmission and hospitalization rates, and invasive mechanical ventilation. Where applicable, relative risk (RR) and weighted mean difference (WMD) were extracted, pooled, and assessed using meta-analysis. Sensitivity analysis was performed to explore the source of heterogeneity.

RESULTS

Fifteen high-quality studies including 14 cohort studies and one case-control study were included in the meta-analysis. Compared with non-eosinophilic AECOPD patients, those with eosinophilic AECOPD had a lower risk of mortality (RR = 0.65, 95 % confidence interval [CI] 0.54, 0.77, P < 0.001), shorter length of hospital stay (WMD = -1.56, 95%CI -2.16, -0.96, P < 0.001), and higher readmission rate (RR = 1.07, 95%CI 1.01,1.13, P = 0.029). No difference was found concerning the rate of hospitalization and invasive mechanical ventilation between the two groups.

CONCLUSION

Individuals diagnosed with eosinophilic AECOPD had a reduced mortality rate, a truncated period of hospitalization, and an insubstantial increase in the probability of readmission relative to their non-eosinophilic AECOPD counterparts. The level of eosinophils in blood has been shown to serve as a potential predictive biomarker for AECOPD patients.

Predictors of Readmission, for Patients with Chronic Obstructive Pulmonary Disease (COPD) - A Systematic Review

Introduction

Chronic obstructive pulmonary disease (COPD) is the third-leading cause of death globally and is responsible for over 3 million deaths annually. One of the factors contributing to the significant healthcare burden for these patients is readmission. The aim of this review is to describe significant predictors and prediction scores for all-cause and COPD-related readmission among patients with COPD.

Methods

A search was conducted in Ovid MEDLINE, Ovid Embase, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials, from database inception to June 7, 2022. Studies were included if they reported on patients at least 40 years old with COPD, readmission data within 1 year, and predictors of readmission. Study quality was assessed. Significant predictors of readmission and the degree of significance, as noted by the p-value, were extracted for each study. This review was registered on PROSPERO (CRD42022337035).

Results

In total, 242 articles reporting on 16,471,096 patients were included. There was a low risk of bias across the literature. Of these, 153 studies were observational, reporting on predictors; 57 studies were observational studies reporting on interventions; and 32 were randomized controlled trials of interventions. Sixty-four significant predictors for all-cause readmission and 23 for COPD-related readmission were reported across the literature. Significant predictors included 1) pre-admission patient characteristics, such as male sex, prior hospitalization, poor performance status, number and type of comorbidities, and use of long-term oxygen; 2) hospitalization details, such as length of stay, use of corticosteroids, and use of ventilatory support; 3) results of investigations, including anemia, lower FEV1, and higher eosinophil count; and 4) discharge characteristics, including use of home oxygen and discharge to long-term care or a skilled nursing facility.

Conclusion

The findings from this review may enable better predictive modeling and can be used by clinicians to better inform their clinical gestalt of readmission risk.

Admission blood eosinophil count, inpatient death and death at 1 year in exacerbating patients with COPD

BACKGROUND

Blood eosinophil counts have been studied in patients with stable chronic obstructive pulmonary disease (COPD) and are a useful biomarker to guide inhaled corticosteroid use. Less is known about eosinophil counts during severe exacerbation.

METHODS

In this retrospective study, 2645 patients admitted consecutively with COPD exacerbation across six UK hospitals were included in the study, and the clinical diagnosis was confirmed by a respiratory specialist. The relationship between admission eosinophil count, inpatient death and 1-year death was assessed. In a backward elimination, Poisson regression analysis using the log-link function with robust estimates, patients' markers of acute illness and stable-state characteristics were assessed in terms of their association with eosinopenia.

RESULTS

1369 of 2645 (52%) patients had eosinopenia at admission. Those with eosinopenia had a 2.5-fold increased risk of inpatient death compared with those without eosinopenia (12.1% vs 4.9%, RR=2.50, 95% CI 1.88 to 3.31, p<0.001). The same mortality risk with eosinopenia was seen among the subgroup with pneumonic exacerbation (n=788, 21.3% vs 8.5%, RR=2.5, 95% CI 1.67 to 2.24, p<0.001). In a regression analysis, eosinopenia was significantly associated with: older age and male sex; a higher pulse rate, temperature, neutrophil count, urea and C reactive protein level; a higher proportion of patients with chest X-ray consolidation and a reduced Glasgow Coma Score; and lower systolic and diastolic blood pressure measurements and lower oxygen saturation, albumin, platelet and previous admission counts.

DISCUSSION

During severe COPD exacerbation, eosinopenia is common and associated with inpatient death and several markers of acute illness. Clinicians should be cautious about using eosinophil results obtained during severe exacerbation to guide treatment decisions regarding inhaled corticosteroid use.

The Prognostic Value of Blood Eosinophil Level in AECOPD is Influenced by Corticosteroid Treatment During Hospitalization

PURPOSE

Blood eosinophil is a promising biomarker for phenotyping patients with acute exacerbation of COPD (AECOPD). We aimed to evaluate the prognostic value of eosinophil on short- and long-term outcomes stratified by corticosteroid treatment among AECOPD inpatients.

PATIENTS AND METHODS

In this retrospective cohort study, we included patients hospitalized for AECOPD from July 2013 to June 2021 in Beijing, China. Clinical data were collected from electronic medical records. The blood eosinophil count was measured within 24h after admission. Eosinophilic AECOPD was defined as having an eosinophil percentage ≥ 2%. The study outcomes were length of stay (LOS), treatment failure, and AECOPD readmission risk within 3 years of discharge. Multivariable models were used to analyze the associations between blood eosinophil count and outcomes stratified by corticosteroid treatment during hospitalization.

RESULTS

A total of 2406 AECOPD patients were included. The median LOS of AECOPD patients was 10 (interquartile range: 8-14) days. The eosinophil percentage was negatively associated with LOS (P-trend=0.014). Compared with the non-eosinophilic AECOPD group, the eosinophilic group had a 58% lower risk of treatment failure (OR=0.42, 95% CI: 0.20-0.89) in patients treated with systemic corticosteroids, but no association was observed in those treated with inhaled corticosteroids (ICS) only (OR=0.95, 95% CI: 0.60-1.52). The eosinophilic group had an increased risk of 90-day re-admission in patients treated with ICS only (HR=1.51, 95% CI: 1.00-2.29), but not in patients treated with systemic corticosteroids during hospitalization (HR=0.67, 95% CI: 0.39-1.15). No statistically significant results were found for 180-day, 1-year, or 3-year readmission risk.

CONCLUSION

Elevated blood eosinophils in AECOPD were associated with shorter length of stay and improved response to treatment with systemic corticosteroids, but not inhaled corticosteroids. Our study suggested that a therapeutic approach of using systemic corticosteroid may benefit patients present with eosinophilic AECOPD.

Re-exacerbation within 30 days of discharge is associated with poor prognosis in the following year among patients hospitalised with exacerbation of chronic obstructive pulmonary disease: a clinical cohort study

BACKGROUND

Exacerbation of chronic obstructive pulmonary disease (ECOPD) is a complex phenomenon, with marked heterogeneity in the aetiology, pathophysiology and clinical manifestations. This study aimed to evaluate the clinical characteristics and long-term outcomes of patients with 30-day exacerbation among those hospitalised with ECOPD in China.

METHODS

Data from the Acute Exacerbations of Chronic Obstructive Pulmonary Disease Inpatient Registry were used in this study. The patients were divided into re-event and non-event groups based on the incidence of re-exacerbation within 30 days of discharge. Exacerbation, severe exacerbation and all-cause readmissions in the following 12 months were the outcomes of interest. The cumulative incidence rates and incidence densities were calculated. Multivariate hazard function models were used to determine the association between 30-day re-exacerbation and the long-term outcomes after accounting for the competing risk of death.

RESULTS

Re-exacerbation within 30 days of discharge was observed in 4.9% (n=242) of the patients (n=4963). The cumulative incidence rates and incidence densities of exacerbation, severe exacerbation and all-cause readmissions in the event group were significantly higher than those in the non-event group. After adjustment, re-exacerbation within 30 days of discharge was associated with increased risks of exacerbation, severe exacerbation and all-cause readmissions in the following 12 months (adjusted HR: 3.85 (95% CI: 3.09 to 4.80), 3.46 (2.66 to 4.50) and 3.28 (2.52 to 4.25) accordingly).

CONCLUSION

Re-exacerbation of COPD within 30 days of discharge is a significant predictor of long-term prognosis. In clinical practice, short-term re-exacerbation is a significant clinical phenotype of ECOPD that requires careful management at the earliest.

Blood Eosinophil Count as a Predictive Biomarker of Chronic Obstructive Pulmonary Disease Exacerbation in a Real-World Setting

Introduction

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death, and COPD exacerbation worsens the prognosis. Eosinophilic airway inflammation is a COPD phenotype that causes COPD exacerbation and is correlated with peripheral blood eosinophil count. We analyzed real-world data of COPD patients to assess the risk factors of COPD exacerbation focusing on blood eosinophils.

Materials and Methods

Patients with COPD who visited our hospital between January 1, 2018, and December 31, 2018, were recruited, and their background information, spirometry data, laboratory test results, and moderate-to-severe exacerbation events during the one-year follow-up period were collected from the electronic medical records and analyzed. The COPD exacerbation risk factors were assessed using univariate and multivariate logistic regression analyses.

Results

Twenty-two of 271 (8.1%) patients experienced moderate-to-severe exacerbation. Patients with exacerbation showed worse pulmonary function, and we found that a high blood eosinophil count (≥350 cells/μL; p=0.014), low % FEV1 (<50%; p=0.002), increase in white blood cell (≥9000 cells/μL; p=0.039), and use of home oxygen therapy (p=0.005) were risk factors for future exacerbations. We also found a strong correlation between eosinophil count cut-offs and exacerbation risk (r = 0.89, p < 0.001). On the other hand, there was no relation between exacerbation risk and inhalation therapy for COPD.

Conclusion

In a real-world setting, peripheral blood eosinophil count could be a predictor of future COPD 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.

Toward a Predict and Prevent Approach in Obstructive Airway Diseases

Asthma and chronic obstructive pulmonary disease are currently diagnosed and treated after the demonstration of variable airflow limitation and symptoms. Under this framework, undiagnosed and unchecked airway inflammation is associated with recurrent acute attacks, airway remodeling, airflow limitation, adverse effects of corticosteroids, and impaired quality of life, ultimately leading to the collection of side effects termed "people remodeling." This one-size-fits-all damage control approach aims to control symptoms and treat exacerbations rather than modify the underlying disease process. The advent of highly effective therapies targeting proximal drivers of airway inflammation calls for a paradigm shift; upstream-acting therapies offer potential to alter the disease course and achieve clinical remission. We propose moving away from downstream firefighting and toward a "predict and prevent" model, measuring inflammation and providing anti-inflammatory therapy early, without waiting for further clinical deterioration. Much in the same way that high blood pressure and cholesterol are used to predict and prevent heart attacks, in asthma, elevated blood eosinophils and/or exhaled nitric oxide can be used to predict and prevent asthma attacks. We also advocate moving research further upstream by identifying patients with subclinical airway inflammation or disease who may be at risk of progressing to airflow limitation and associated morbidities and intervening early to prevent them. In summary, we call for a predict and prevent approach in obstructive airway disease.

Predictive value of neutrophil-to-lymphocyte ratio and bilirubin levels in the readmission of acute exacerbation of chronic obstructive pulmonary disease

BACKGROUND

Th aim of this study was to analyze acute exacerbation of chronic obstructive pulmonary disease (AECOPD) readmission events and to determine whether neutrophil-to-lymphocyte ratio (NLR) and bilirubin levels were associated with readmission after discharge due to AECOPD.

METHODS

A total of 170 patients with AECOPD were included. Patients were stratified into the readmission group if patients had two or more readmissions within 2 years of the previous discharge, and the non-readmission group with one readmission or none within 2 years of the last discharge. Data were collected and compared between groups. The patients were separated by the cutoffs of NLR and bilirubin level. The number of all-cause readmissions within 2 years, time to first COPD-related readmission, 1-year/2-year COPD-related readmission, 1-year/2-year all-cause mortality were compared between groups, respectively.

RESULTS

Compared with the readmission group, patients of the non-readmission group had a shorter length of hospital stay, more systemic corticosteroid use, higher NLR, higher bilirubin levels, and lower eosinophils counts (p < 0.05). NLR and bilirubin levels on admission had significant association with the number of all-cause readmissions (p < 0.05). Lower bilirubin was associated with an increased risk of 1-year COPD-related readmission (OR 5.063) and 2-year COPD-related readmission (OR 4.699).

CONCLUSIONS

For patients with AECOPD, longer hospital stay, and less use of systemic corticosteroids may be associated with a higher risk of readmission. NLR and bilirubin levels on admission may be related to the number of all-cause readmissions. Bilirubin can be regarded as a biomarker to predict readmission rates within 2 years after discharged throughout the course of the disease.

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.

Readmission rate for acute exacerbation of chronic obstructive pulmonary disease: A systematic review and meta-analysis

BACKGROUND

The readmission rate following hospitalization for chronic obstructive pulmonary disease (COPD) exacerbations is extremely high and has become a common and challenging clinical problem. This study aimed to systematically summarize COPD readmission rates for acute exacerbations and their underlying risk factors.

METHODS

A comprehensive search was performed using PubMed, Embase, Cochrane Library, and Web of Science, published from database inception to April 2, 2022. Methodological quality was evaluated using the Newcastle-Ottawa Scale (NOS). We used a random-effects model or a fixed-effects model to estimate the pooled COPD readmission rate for acute exacerbations and underlying risk factors.

RESULTS

A total of 46 studies were included, of which 24, 7, 17, 7, and 20 summarized the COPD readmission rates for acute exacerbations within 30, 60, 90, 180, and 365 days, respectively. The pooled 30-, 60-, 90-, 180-, and 365-day readmission rates were 11%, 17%, 17%, 30%, and 37%, respectively. The study design type, age stage, WHO region, and length of stay (LOS) were initially considered to be sources of heterogeneity. We also identified potential risk factors for COPD readmission, including male sex, number of hospitalizations in the previous year, LOS, and comorbidities such as heart failure, tumor or cancer, and diabetes, whereas obesity was a protective factor.

CONCLUSIONS

Patients with COPD had a high readmission rate for acute exacerbations, and potential risk factors were identified. Therefore, we should propose clinical interventions and adjust or targeted the control of avoidable risk factors to prevent and reduce the negative impact of COPD readmission.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, identifier CRD42022333581.

Simultaneous evaluation of the fractional exhaled nitric oxide and blood eosinophil count of T2-high endotype in patients with non-cystic fibrosis bronchiectasis

OBJECTIVE

Recently, a type 2 inflammation (T2) high endotype in bronchiectasis was identified. The fraction of exhaled nitric oxide (FeNO) and blood eosinophil count (BEC) are recognized as representative biomarkers of T2 inflammation. Herein, we investigate the clinical characteristics of T2-high endotype in non-cystic fibrosis bronchiectasis patients classified by FeNO and BEC.

METHODS

This retrospective study included 164 bronchiectasis patients treated in the First Affiliated Hospital of Sun Yat-sen University from December 2017 to July 2022. Clinical characteristics were analyzed after classifying patients into four groups according to T2 inflammation biomarkers (FeNO ≥25 ppb; BEC ≥200/µL).

RESULTS

Among the 164 bronchiectasis patients, 35.3% (58/164) presented with high FeNO, 30.5% (50/164) presented with high BEC, and 10.4% (17/164) had high FeNO and BEC. Patients with high FeNO and low BEC presented with better lung function, fewer affected lobes, and lower dyspnea prevalence compared with the three other groups. Moreover, decreased FeNO, instead of decreased BEC, is revealed to be an independent predictor for disease severity and airflow obstruction in bronchiectasis.

CONCLUSIONS

Simultaneous evaluation of FeNO and BEC proposed different endotypes of bronchiectasis established that patients with low BEC and high FeNO had better lung function, fewer affected lobes, lower dyspnea prevalence, and less disease severity. This result will contribute to a more comprehensive assessment of the disease severity and lead to more precise treatment of T2 inflammation in bronchiectasis patients.

Blood and sputum eosinophilia in COPD exacerbation

Background

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

Objectives

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

Subjects and methods

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

Results

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

Conclusion

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

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.

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.

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.

Prognostic risk factors for moderate-to-severe exacerbations in patients with chronic obstructive pulmonary disease: a systematic literature review

Background

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity and mortality worldwide. COPD exacerbations are associated with a worsening of lung function, increased disease burden, and mortality, and, therefore, preventing their occurrence is an important goal of COPD management. This review was conducted to identify the evidence base regarding risk factors and predictors of moderate-to-severe exacerbations in patients with COPD.

Methods

A literature review was performed in Embase, MEDLINE, MEDLINE In-Process, and the Cochrane Central Register of Controlled Trials (CENTRAL). Searches were conducted from January 2015 to July 2019. Eligible publications were peer-reviewed journal articles, published in English, that reported risk factors or predictors for the occurrence of moderate-to-severe exacerbations in adults age ≥ 40 years with a diagnosis of COPD.

Results

The literature review identified 5112 references, of which 113 publications (reporting results for 76 studies) met the eligibility criteria and were included in the review. Among the 76 studies included, 61 were observational and 15 were randomized controlled clinical trials. Exacerbation history was the strongest predictor of future exacerbations, with 34 studies reporting a significant association between history of exacerbations and risk of future moderate or severe exacerbations. Other significant risk factors identified in multiple studies included disease severity or bronchodilator reversibility (39 studies), comorbidities (34 studies), higher symptom burden (17 studies), and higher blood eosinophil count (16 studies).

Conclusions

This systematic literature review identified several demographic and clinical characteristics that predict the future risk of COPD exacerbations. Prior exacerbation history was confirmed as the most important predictor of future exacerbations. These prognostic factors may help clinicians identify patients at high risk of exacerbations, which are a major driver of the global burden of COPD, including morbidity and mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-022-02123-5.

Factors affecting length of hospital stay in chronic obstructive pulmonary disease patients in a tertiary hospital of Nepal: A retrospective cross-sectional study

Background

Despite the increasing burden of chronic obstructive pulmonary disease in Nepal, studies analyzing the factors associated with inpatient length of hospital stay are lacking.

Methods

This is a retrospective, cross-sectional hospital-based study conducted between July 2020 and July 2021 on patients admitted to the inpatient ward of Pulmonary and Critical Care Medicine of Tribhuvan University Teaching Hospital with a primary diagnosis of acute exacerbation of chronic obstructive pulmonary disease. The sample size of our study was 90. Clinical and demographic factors, blood investigation parameters, and treatment received were analyzed via univariate and multivariate analysis to find the factors associated with length of stay.

Results

The mean age of chronic obstructive pulmonary disease patients was 68.84 ± 10.22 years, with 42.2% of males and 43.3% of current smokers. The length of hospital stay ranged from 2 to 25 days, with an average stay of 6.69 ± 4.02 days. Factors associated with length of stay are the number of comorbidities (p = 0.007), blood eosinophils at admission (p = 0.022), and use of mechanical ventilatory support (p < 0.001).

Conclusions

Proper management of comorbidities and eosinophilic exacerbations as well as careful use of mechanical ventilatory support are required to further reduce the duration of hospital stay in chronic obstructive pulmonary disease patients.

•

This study is the first of its kind identifying the factors associated with the length of hospital stay in COPD patients in Nepal.

•

COPD is the fifth most common cause of inpatient admission in Nepal and per our study the length of stay was 6.69 days.

•

The culprits identified for the increase length of stay were the number of comorbidities, blood eosinophils at admission and use of mechanical ventilator support.

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.

Low Eosinophil Phenotype Predicts Noninvasive Mechanical Ventilation Use in Patients with Hospitalized Exacerbations of COPD

Rationale

Objective

Methods

Results

Conclusion

Predictors of Influenza PCR Positivity in Acute Exacerbations of Chronic Obstructive Pulmonary Disease

Purpose

Influenza infection is an important cause of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Clinical features predicting influenza PCR positivity are unknown. We aim to identify predictors of influenza PCR positivity in AECOPD.

Patients and Methods

A retrospective study of AECOPD cases admitted between 1st January 2016 to 30 June 2017 with combined nasal/throat swabs sent for influenza PCR (Xpert Xpress Flu/RSV) within 24 hours of admission was performed. Clinical parameters and investigations within 24 hours of admission were retrieved from electronic medical records.

Results

Influenza PCR were sent for 925 AECOPD cases (mean age 75 years, 87.9% male). There were 90 PCR positive cases (68 Influenza A, 22 Influenza B). Influenza PCR positive cases had higher temperatures, higher heart rates, lower white cell and lower eosinophil counts. Age, gender, COPD severity, comorbidities and smoking status were similar in both groups. There were no differences in blood pressure, oxygen status, neutrophil or lymphocyte counts, C reactive protein, procalcitonin or chest X-ray consolidation between groups. Higher temperature, higher heart rate, white cell count in the lowest quartile (Q1 < 8.1 x10⁹/L) and non-eosinophilic exacerbations predicted influenza PCR positivity on univariate logistic regression and these factors remained significant after multivariate adjustment (temperature adjusted odds ratio [adj OR] 1.324 [1.009–1.737], p = 0.043; heart rate adj OR 1.017 [1.004–1.030], p = 0.011; white cell count Q1 adj OR 3.330 [1.690–6.562], p = 0.001; eosinophilic exacerbations adj OR 0.390 [0.202–0.756], p = 0.005).

Conclusion

Higher temperature, higher heart rate, low white cell count (especially when < 8.1 x10⁹/L) and non-eosinophilic exacerbations are independent predictors of influenza PCR positivity in AECOPD cases.

Changes in systemic inflammation after pulmonary rehabilitation in patients with COPD and severe physical inactivity - an exploratory study

Background: Severe physical inactivity (SPI) in patients with COPD is associated with a poor prognosis. It is unknown whether there is a link between SPI and systemic inflammation, and if systemic inflammation in SPI changes following pulmonary rehabilitation (PR).

Methods: A prospective, observational study of patients referred for at least 7 weeks of PR comprising 2 h of exercise therapy and education twice weekly. At baseline and after PR, daily physical activity level (PAL) was measured with a validated activity monitor, SenseWear^® as well as systemic inflammation: b-eosinophils, p-fibrinogen, p-CRP, s-IL-6 and s-CD 163. SPI was defined as PAL <1.4.

Results: At baseline, SPI was present in 31 of the 57 patients included, and 23% (7/31) improved to non-SPI after PR. We observed no differences between patients with SPI and non-SPI, except baseline plasma fibrinogen level was slightly yet significantly higher in patients with SPI (median 13.3 [6.2–23.6] vs 11.2 [6.5–16.7] µmol/l) but change in fibrinogen levels differed insignificantly between patients who improved to non-SPI at follow-up compared to patients with persistent SPI (−0.6 [−16.9–9.9] vs −0.4 [−11.2–1.2] µmol/l).

Conclusion: SPI in COPD appears not to be associated with a distinct inflammatory profile compared to less sedentary COPD patients attending pulmonary rehabilitation. Currently biomarkers have no role in the detection of SPI in COPD.

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

Introduction

Methods

Results

Conclusion

COPD - do the right thing

A gap exists between guidelines and real-world clinical practice for the management and treatment of chronic obstructive pulmonary disease (COPD). Although this has narrowed in the last decade, there is room for improvement in detection rates, treatment choices and disease monitoring. In practical terms, primary care practitioners need to become aware of the huge impact of COPD on patients, have non-judgemental views of smoking and of COPD as a chronic disease, use a holistic consultation approach and actively motivate patients to adhere to treatment.This article is based on discussions at a virtual meeting of leading Nordic experts in COPD (the authors) who were developing an educational programme for COPD primary care in the Nordic region. The article aims to describe the diagnosis and lifelong management cycle of COPD, with a strong focus on providing a hands-on, practical approach for medical professionals to optimise patient outcomes in COPD primary care.

Blood eosinophils in COPD: friend or foe?

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Monoclonal Antibodies Targeting IL-5 or IL-5Rα in Eosinophilic Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis

Background: Although the predominant airway inflammation in chronic obstructive pulmonary disease (COPD) is neutrophilic, approximately 20-40% of COPD patients present with eosinophilic airway inflammation. Compared with non-eosinophilic COPD patients, eosinophilic COPD patients are characterized by a greater number of total exacerbations and higher hospitalization rates. Furthermore, anti-interleukin-5 (IL-5) therapy, consisting of monoclonal antibodies (mAbs) targeting IL-5 or IL-5 receptor α (IL-5Rα), has been proven to be effective in severe eosinophilic asthma. This meta-analysis aimed to determine the efficacy and safety of anti-IL-5 therapy in eosinophilic COPD. Methods: We searched the PubMed, Web of Science, Embase, and Cochrane Library databases from inception to August 2020 (updated in June 2021) to identify studies comparing anti-IL-5 therapy (including mepolizumab, benralizumab, and reslizumab) with placebo in eosinophilic COPD patients. Results: Anti-IL-5 therapy was associated with a decrease in acute exacerbation rate (RR 0.89; 95% CI 0.84 to 0.95, I ² = 0%) and the severe adverse events (RR 0.90; 95% CI 0.84 to 0.97, I ² = 0%). However, no significant improvement was observed in pre-bronchodilator forced expiratory volume in 1 s (FEV₁) (WMD 0.01; 95% CI -0.01 to 0.03, I ² = 25.9%), SGRQ score (WMD -1.17; 95% CI -2.05 to -0.29, I ² = 0%), and hospital admission rate (RR 0.91; 95% CI 0.78 to 1.07, I ² = 20.8%). Conclusion: Anti-IL-5 therapy significantly reduced the annual acute exacerbation rate and severe adverse events in eosinophilic COPD patients. However, it did not improve lung function, quality of life, and hospitalization rate.

Blood Eosinophils and Pulmonary Rehabilitation in COPD

Background

Blood eosinophils predict the response to therapy, risk of exacerbation, and readmission in COPD. This study investigates whether blood eosinophils predict pulmonary rehabilitation (PR) outcomes in COPD.

Methods

We categorized patients into eosinophilic (blood eosinophils ≥300 cells/ml) or noneosinophilic (<300 cells/ml). In a retrospective design, we compared changes within and between the two groups on BODE index, 6-minute walk test (6MWT), FEV1, and mMRC dyspnea scale.

Results

Of 206 patients enrolled, 176 were included for analysis; 90 were eosinophilic. BODE index improved in both groups: (MD -1.25; 95% CI (-0.45, -4.25), P ≤ 0.001) in the eosinophilic and (MD -1.33; 95% CI (-1.72, -0.94), P ≤ 0.001) in the noneosinophilic, but a higher BODE index remained in the eosinophilic (4.98); adjusted mean change (β): 0.7 (95% CI (0.15, 1.26), P=0.01). 6MWT improved by 29.3 m in the eosinophilic (95% CI (14.2, 44.4), P ≤ 0.001) vs. 115.1 m in the noneosinophilic (95% CI (-30.4, 260.6), P=0.12). FEV1 did not change in the eosinophilic (MD -0.6; 95% CI (-2.64, 1.48), P=0.58), but improved by 2.5% in the noneosinophilic (MD 2.5; 95% CI (0.77, 4.17), P=0.005). There were no significant between-group differences in 6MWT and FEV1; adjusted mean changes (β) were -9.69 m (95% CI (-39.51, 20.14), P=0.52) and -2.31% (95% CI (-5.69, 1.08), P=0.18), respectively. There were no significant within- or between-group changes in the mMRC scale.

Conclusion

Although PR improves the BODE index in both eosinophilic and noneosinophilic COPD, a higher eosinophil count (≥300 cells/ml) is associated with a higher (worse) BODE index. Blood eosinophils may predict PR outcomes.

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.

Characterization Associated with the Frequent Severe Exacerbator Phenotype in COPD Patients

Background

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

Methods

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

Results

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

Conclusion

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

Treatment Response Biomarkers in Asthma and COPD

Chronic obstructive pulmonary disease (COPD) and asthma are two of the most common chronic diseases worldwide. Both diseases are heterogenous and complex, and despite their similarities, they differ in terms of pathophysiological and immunological mechanisms. Mounting evidence supports the presence of several phenotypes with various responses to treatment. A systematic and thorough assessment concerning the diagnosis of both asthma and COPD is crucial to the clinical management of the disease. The identification of different biomarkers can facilitate targeted treatment and monitoring. Thanks to the presence of numerous immunological studies, our understanding of asthma phenotypes and mechanisms of disease has increased markedly in the last decade, and several treatments with monoclonal antibodies are available. There are compelling data that link eosinophilia with an increased risk of COPD exacerbations but a greater treatment response and lower all-cause mortality. Eosinophilia can be considered as a treatable trait, and the initiation of inhaled corticosteroid in COPD patients with eosinophilia is supported in many studies. In spite of advances in our understanding of both asthma and COPD in terms pathophysiology, disease mechanisms, biomarkers, and response to treatment, many uncertainties in the management of obstructive airways exist.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Comparison of Immediate and Sequential Withdrawal of a Systemic Glucocorticoid in the Treatment of Acute Exacerbations of Chronic Obstructive Pulmonary Disease: A Multicenter, Randomized, Double-Blind, Parallel-Controlled, Open-Label Study

Patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) were treated with immediate or sequential withdrawal after 5 days of systemic glucocorticoids. The effects of the two withdrawal methods on the prognosis of patients were compared at 30, 90, 180, and 360 days after discharge. A multicenter, randomized, double-blind, parallel-controlled, open-label study was conducted in the respiratory department of tertiary hospitals in Central China. Patients met inclusion criteria for AECOPD and needed to use systemic glucocorticoids. They were randomly assigned to immediate and sequential withdrawal groups at a 1:1 ratio. The study was completed in August 2020 and is registered at the China Clinical Trials Registry (Chictr.org) (ChiCTR1800018894). According to general data and clinical characteristics, there were no statistically significant differences between the 329 patients in the immediate withdrawal group and the 310 patients in the sequential withdrawal group (P > 0.05). At the 30, 90, 180, and 360-days follow-up, the acute exacerbation frequency, rehospitalization rate, mortality, and intensive care unit (ICU) treatment rate were not significantly different between the immediate withdrawal group and sequential withdrawal group (P > 0.05). The modified Medical Research Council (mMRC) and COPD assessment test (CAT) scores were also not significantly different between the two groups. At the 180- and 360-day follow-up, forced expiratory volume in 1 s (FEV1%) and peak expiratory flow (PEF) were not significantly different between the two groups (P > 0.05). The time from discharge to first acute exacerbation was significantly lower in the immediate withdrawal group (46.12 days) than in sequential withdrawal group (49.02 days) (P < 0.05). The time of stay in the hospital for the first time after discharge was not significantly different between the two groups (P > 0.05). Adverse events were not significantly different between the immediate withdrawal group and sequential withdrawal group (P < 0.05). Subgroup analysis was performed according to age, degree of disease, and relevant indicators. At the 30-day follow-up, the acute exacerbation frequency of patients with advanced age, high global strategy for chronic obstructive lung disease (GOLD), and high fractional exhaled nitric oxide was significantly higher in the immediate withdrawal group than in the sequential withdrawal group (P < 0.05). In addition, according to receiver operating characteristic (ROC) curve analysis, the frequency of acute exacerbations at the 30-day follow-up was significantly higher in patients with age > 63.5 years or GOLD > 3 in the immediate withdrawal group than in the sequential withdrawal group, suggesting that the short-term efficacy was poor.

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

Background

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

Methods

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

Results

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

Conclusion

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

Blood eosinophil counts and the development of obstructive lung disease: the Kangbuk Samsung Health Study

The impact of blood eosinophil counts on the development of chronic obstructive lung disease (COPD) is unknown. We investigated whether a higher blood eosinophil counts was associated with the risk of developing obstructive lung disease (OLD) in a large cohort of men and women free lung disease at baseline.Cohort study of 359 456 Korean adults without a history of asthma and without OLD at baseline who participated in health screening exams including spirometry. OLD was defined as pre-bronchodilator FEV₁/FVC<0.7 and FEV₁<80% predicted.After a median follow-up of 5.6 years (interquartile range, 2.9-9.2), 5008 participants developed incident OLD (incidence rate, 2.1 per 1000 person-years; 95% CI, 2.1-2.2). In the fully-adjusted model, the HR (95% CI) for incident OLD comparing eosinophil counts of 100-<200, 200-<300, 300-<500 and ≥500 cells·μL^-1 to <100 cells·μL^-1 were 1.07 (1.00-1.15), 1.30 (1.20-1.42), 1.46 (1.33-1.60) and 1.72 (1.51-1.95) (p for trend <0.001). These associations were consistent in clinically relevant subgroups, including never, former, and current smokers.In this large longitudinal cohort study, blood eosinophil counts were positively associated with the risk of developing of OLD. Our findings indicate a potential role of eosinophil count as an independent risk factor for developing COPD.

Preventing COPD Readmissions Under the Hospital Readmissions Reduction Program: How Far Have We Come?

The Hospital Readmissions Reduction Program (HRRP) was developed and implemented by the Centers for Medicare & Medicaid Services to curb the rate of 30-day hospital readmissions for certain common, high-impact conditions. In October 2014, COPD became a target condition for which hospitals were penalized for excess readmissions. The appropriateness, utility, and potential unintended consequences of the metric have been a topic of debate since it was first enacted. Nevertheless, there is evidence that hospital policies broadly implemented in response to the HRRP may have been responsible for reducing the rate of readmissions following COPD hospitalizations even before it was added as a target condition. Since the addition of the COPD condition to the HRRP, several predictive models have been developed to predict COPD survival and readmissions, with the intention of identifying modifiable risk factors. A number of interventions have also been studied, with mixed results. Bundled care interventions using the electronic health record and patient education interventions for inhaler education have been shown to reduce readmissions, whereas pulmonary rehabilitation, follow-up visits, and self-management programs have not been consistently shown to do the same. Through this program, COPD has become recognized as a public health priority. However, 5 years after COPD became a target condition for HRRP, there continues to be no single intervention that reliably prevents readmissions in this patient population. Further research is needed to understand the long-term effects of the policy, the role of competing risks in measuring quality, the optimal postdischarge care for patients with COPD, and the integrated use of predictive modeling and advanced technologies to prevent COPD readmissions.

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.

Targeting eosinophils in respiratory diseases: Biological axis, emerging therapeutics and treatment modalities

Eosinophils are bi-lobed, multi-functional innate immune cells with diverse cell surface receptors that regulate local immune and inflammatory responses. Several inflammatory and infectious diseases are triggered with their build up in the blood and tissues. The mobilization of eosinophils into the lungs is regulated by a cascade of processes guided by Th2 cytokine generating T-cells. Recruitment of eosinophils essentially leads to a characteristic immune response followed by airway hyperresponsiveness and remodeling, which are hallmarks of chronic respiratory diseases. By analysing the dynamic interactions of eosinophils with their extracellular environment, which also involve signaling molecules and tissues, various therapies have been invented and developed to target respiratory diseases. Having entered clinical testing, several eosinophil targeting therapeutic agents have shown much promise and have further bridged the gap between theory and practice. Moreover, researchers now have a clearer understanding of the roles and mechanisms of eosinophils. These factors have successfully assisted molecular biologists to block specific pathways in the growth, migration and activation of eosinophils. The primary purpose of this review is to provide an overview of the eosinophil biology with a special emphasis on potential pharmacotherapeutic targets. The review also summarizes promising eosinophil-targeting agents, along with their mechanisms and rationale for use, including those in developmental pipeline, in clinical trials, or approved for other respiratory disorders.

Novel Perspectives Regarding the Pathology, Inflammation, and Biomarkers of Acute Respiratory Distress Syndrome

Acute respiratory distress syndrome (ARDS) is an acute inflammation of the lung resulting from damage to the alveolar-capillary membrane, and it is diagnosed using a combination of clinical and physiological variables. ARDS develops in approximately 10% of hospitalised patients with pneumonia and has a mortality rate of approximately 40%. Recent research has identified several biomarkers associated with ARDS pathophysiology, and these may be useful for diagnosing and monitoring ARDS. They may also highlight potential therapeutic targets. This review summarises our current understanding of those clinical biomarkers: (1) biomarkers of alveolar and bronchiolar injury, (2) biomarkers of endothelial damage and coagulation, and (3) biomarkers for treatment responses.

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.

Clinical Differences between Eosinophilic and Noneosinophilic Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Multicenter Cross-Sectional Study

METHODS

A total of 643 AECOPD patients were enrolled in this multicenter cross-sectional study. Finally, 455 were included, 214 in the normal-eosinophil AECOPD (NEOS-AECOPD) group, 63 in the mild increased-eosinophil AECOPD (MEOS-AECOPD) group, and 138 in the severe increased-eosinophil AECOPD (SEOS-AECOPD) group. Demographic data, underlying diseases, symptoms, and laboratory findings were collected. Multiple logistic regression analysis was performed to identify the independent factors associated with blood eosinophils (EOS). Correlations between blood EOS and its associated independent factors were evaluated.

RESULTS

The significant differences in 19 factors, including underlying diseases, clinical symptoms, and laboratory parameters, were identified by univariate analysis. Subsequently, multiple logistic regression analysis revealed that lymphocyte%, neutrophil% (NS%), procalcitonin (PCT), and anion gap (AG) were independently associated with blood EOS in AECOPD. Both blood EOS counts and EOS% were significantly correlated with lymphocyte%, NS%, PCT, and AG.

CONCLUSIONS

Collectively, blood EOS was independently associated with lymphocyte%, NS%, PCT, and AG in AECOPD patients. Lymphocyte% was lower, and NS%, PCT, and AG were higher in eosinophilic AECOPD. Our results indicate that viral-dominant infections are the probable major etiologies of eosinophilic AECOPD. Noneosinophilic AECOPD is more likely associated with bacterial-dominant infections. The systemic inflammation in noneosinophilic AECOPD was more severe.

Role of acute exacerbations in skeletal muscle impairment in COPD

Introduction: Muscle impairments are prevalent in COPD and have adverse clinical implications in terms of physical performance capacity, disease burden, quality of life and even mortality. During acute exacerbations of COPD (AECOPDs) the respiratory symptoms worsen and this might also apply to the muscle impairments. Areas covered: This report includes a review of both clinical and pre-clinical peer-reviewed literature of the past 20 years found in PubMed providing a comprehensive view on the role of AECOPD in muscle dysfunction in COPD, the putative underlying mechanisms and the treatment perspectives. Expert opinion: The contribution of AECOPD and its recurrent nature to muscle impairment in COPD cannot be ignored and can be attributed to the acutely intensifying and converging disease-related drivers of muscle deterioration, in particular disuse, systemic inflammation and corticosteroid treatment. The search for novel treatment options should focus on the AECOPD-enhanced drivers of muscle dysfunction as well as on the underlying, mainly catabolic, mechanisms. Considering the impact of AECOPD on muscle function, and that of muscle impairment on the recurrence of exacerbations, counteracting muscle deterioration in AECOPD provides an unprecedented therapeutic opportunity.

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.

Blood Eosinophil Count and Hospital Readmission in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Purpose

This retrospective, observational cohort study investigated the association of blood eosinophil counts within 1 week of hospitalization for acute exacerbation of COPD (AECOPD) with subsequent risk of all-cause and COPD-related readmission from a large integrated health system.

Patients and Methods

Electronic medical records were extracted for index hospitalization for AECOPD at all Intermountain Healthcare hospitals. The primary outcome was the relationship of blood eosinophil count to 30-day all-cause readmission; secondary outcomes were 60-day, 90-day, and 12-month all-cause readmission, COPD-related readmission, and empiric derivation of the eosinophil count with the highest area under the curve (AUC) for predicting 30-day all-cause readmission.

Results

Of 2445 included patients, 1935 (79%) had a blood eosinophil count <300 cells/µL and 510 (21%) had a count ≥300 cells/µL. Using a 300-cells/μL threshold, there was no significant difference between high and low eosinophil groups in 30-day (odds ratio [OR]=1.05, 95% confidence interval [CI]=0.75–1.47) or 60-day (OR=1.15, 95% CI=0.88–1.51) all-cause readmissions. However, patients with greater (versus lesser) eosinophil counts had increased 90-day and 12-month all-cause readmissions (OR=1.35, 95% CI=1.06–1.72, and OR=1.32, 95% CI=1.07–1.62). COPD-related readmission rates were significantly greater for patients with greater (versus lesser) eosinophil counts at 30, 60, and 90 days and 12 months (OR range=1.52–1.97). A total of 70 cells/µL had the most discriminatory power to predict 30-day all-cause readmission (highest AUC).

Conclusion

Eosinophil counts in patients with COPD were not associated with a difference in 30-day all-cause readmissions. However, greater eosinophil counts were associated with increased risk of all-cause readmission at 90 days and 12 months and COPD-related readmission at 30, 60, and 90 days and 12 months. Patients with eosinophils <70 cells/μL had the lowest risk for 30-day all-cause readmission. Blood eosinophils in patients hospitalized with AECOPD may be a useful biomarker for the risk of hospital readmission.

Blood eosinophil count predicts treatment failure and hospital readmission for COPD

We examined associations between blood eosinophil counts (BEC) and risk of treatment failure or hospital readmission following acute oral corticosteroid (OCS)-treated COPD exacerbations. We conducted studies from the Optimum Patient Care Research Database (OPCRD) (www.optimumpatientcare.org/opcrd) and Clinical Practice Research Datalink (CPRD) (www.cprd.com/home/), validated databases for medical research, with linked Hospital Episode Statistics (HES) data for ∼20 000 COPD patients aged ≥40 years. For patients with OCS-treated COPD exacerbations treated in primary care, with BECs recorded on first day of OCS treatment (Cohort 1), we assessed treatment failure (COPD-related hospitalisations and OCS prescriptions beyond index OCS course). For patients hospitalised for COPD exacerbations, with BEC measured over an exacerbation-free period during the year prior to admission (Cohort 2), we assessed readmission rate. Cox proportional hazards regression analysis was adjusted for confounders to estimate the association between BEC and treatment outcomes. Of patients treated with OCS for COPD exacerbations in primary care (Cohort 1), 44% experienced treatment failure following single OCS courses, and 10% (255/2482) were hospitalised for ≤6 weeks. Greater BEC was associated with reduced hospital-admission risk (hazard ratio [HR]=0.26; 95% CI: 0.12-0.56, per 100 cells·µL-1 increase). BEC increases of ≥200 cells·µL-1 from exacerbation-free periods to exacerbations were associated with least hospitalisation risk (HR=0.32; 95% CI: 0.15-0.71) versus no BEC change. For patients hospitalised for COPD exacerbations (Cohort 2), 4-week hospital readmission was 12% (1189/10 245). BEC increases during an exacerbation-free period within the past year were associated with reduced risk of short-term readmission (HR=0.78; 95% CI: 0.63-0.96). Greater BEC predicted better outcomes for patients with OCS-treated COPD exacerbations, whether community or hospital managed. Eosinopenia predicted worse outcomes.