Eosinophilia is associated with increased all-cause mortality after a follow-up of 30 years in a general population sample

All-cause mortality and related factors in patients with varying degrees of peripheral blood eosinophilia

The aim of this study was to investigate all-cause mortality rates and related factors in patients with different levels of eosinophilia. This retrospective cohort study was conducted between January 2020 and December 2022 in the Internal Medicine Department of Dr Sadi Konuk Training and Research Hospital, Istanbul, Turkiye. A total of 161 patients with eosinophilia (at least 3 times) were included and divided into groups with absolute eosinophil counts of 500-999/µL (mild), 1000-1500/µL (moderate), and >1500/µL (severe). The mean age of patients was 65.67 ± 16.64 years at the time of admission, and 45 patients (57.8%) were male. The rates of mortality, oncological disease, and organ involvement were significantly higher in the severe group (P < .05). Increased serum total immunoglobulin E and vitamin B12, hematocrit value, eosinophil-to-lymphocyte ratio, and leukocyte were observed in eosinophilic patients. Decreased lymphocyte count, hemoglobin and hematocrit values were higher in deceased patients than in survivors (P < .05). Increased eosinophil-to-lymphocyte ratio, C-reactive protein, vitamin B12, and lactate dehydrogenase (LDH) activity were observed in participants who died compared to those who survived (P < .05). Multivariable logistic regression revealed that advanced age and higher LDH activity were independently associated with greater mortality risk while receiving non-steroid anti-inflammatory drugs or proton-pump inhibitors were associated with reduced mortality risk (P < .05). Advanced age and increased LDH activity were independently associated with greater risk for mortality, whereas absolute eosinophil counts was not. Considering the literature on this topic, our results show the need for further clinical and fundamental research to understand the role of eosinophils in human disease.

Identifying prognostic factors for survival in intensive care unit patients with SIRS or sepsis by machine learning analysis on electronic health records

BACKGROUND

Systemic inflammatory response syndrome (SIRS) and sepsis are the most common causes of in-hospital death. However, the characteristics associated with the improvement in the patient conditions during the ICU stay were not fully elucidated for each population as well as the possible differences between the two.

GOAL

The aim of this study is to highlight the differences between the prognostic clinical features for the survival of patients diagnosed with SIRS and those of patients diagnosed with sepsis by using a multi-variable predictive modeling approach with a reduced set of easily available measurements collected at the admission to the intensive care unit (ICU).

METHODS

Data were collected from 1,257 patients (816 non-sepsis SIRS and 441 sepsis) admitted to the ICU. We compared the performance of five machine learning models in predicting patient survival. Matthews correlation coefficient (MCC) was used to evaluate model performances and feature importance, and by applying Monte Carlo stratified Cross-Validation.

RESULTS

Extreme Gradient Boosting (MCC = 0.489) and Logistic Regression (MCC = 0.533) achieved the highest results for SIRS and sepsis cohorts, respectively. In order of importance, APACHE II, mean platelet volume (MPV), eosinophil counts (EoC), and C-reactive protein (CRP) showed higher importance for predicting sepsis patient survival, whereas, SOFA, APACHE II, platelet counts (PLTC), and CRP obtained higher importance in the SIRS cohort.

CONCLUSION

By using complete blood count parameters as predictors of ICU patient survival, machine learning models can accurately predict the survival of SIRS and sepsis ICU patients. Interestingly, feature importance highlights the role of CRP and APACHE II in both SIRS and sepsis populations. In addition, MPV and EoC are shown to be important features for the sepsis population only, whereas SOFA and PLTC have higher importance for SIRS patients.

Clinical implications of peripheral eosinophil count at diagnosis in patients newly diagnosed with microscopic polyangiitis and granulomatosis with polyangiitis

BACKGROUND

This study investigated the clinical implications of peripheral eosinophil count at diagnosis in estimating cross-sectional antineutrophil cytoplasmic antibody-associated vasculitis (AAV) activity and predicting all-cause mortality during follow-up in patients newly diagnosed with microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA).

METHODS

This study included 224 immunosuppressive drug-naïve patients with peripheral eosinophil count at diagnosis < 1,000/mm3. The Birmingham Vasculitis Activity Score (BVAS), the Five-Factor Score (FFS), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) at diagnosis were assessed.

RESULTS

The median age of the 224 patients (152 MPA and 72 GPA) was 62.0 years; 35.3% of them were men. At diagnosis, peripheral eosinophil count was significantly correlated with BVAS (P = 0.001), FFS (P = 0.046), ESR (P < 0.001), and CRP (P < 0.001). Deceased patients had a significantly higher median peripheral eosinophil count at diagnosis than surviving patients (310.0/mm3 vs. 170.0/mm3, P = 0.004). In addition, patients with MPA and those with cardiovascular and renal manifestations at diagnosis exhibited significantly higher peripheral eosinophil counts than those without. When the optimal cut-off of peripheral eosinophil count at diagnosis for all-cause mortality during follow-up was set at 175.0/mm3, Patients with peripheral eosinophil count at diagnosis ≥ 175.0/mm3 exhibited a significantly lower cumulative patients' survival rate than those with peripheral eosinophil count at diagnosis < 175.0/mm3 (P = 0.008).

CONCLUSIONS

This study was the first to demonstrate that peripheral eosinophil count at diagnosis could estimate cross-sectional AAV activity at diagnosis and contribute to predicting all-cause mortality during follow-up in MPA and GPA patients.

Association between Serum Levels of Interleukin-25/Thymic Stromal Lymphopoietin and the Risk of Exacerbation of Chronic Obstructive Pulmonary Disease

Th2 inflammation is associated with various characteristics of patients with chronic obstructive pulmonary disease (COPD). In this study, we analyzed the COPD exacerbation risk associated with serum levels of interleukin (IL)-25/thymic stromal lymphopoietin (TSLP) and eosinophils. We studied the KOCOSS cohort, a multicenter COPD cohort created by 54 medical centers in South Korea. We extracted data collected between April 2012 and August 2020. We measured serum levels of TSLP and IL-25 in those who agreed to provide blood, and assessed exacerbation risk according to each. In all, 562 patients were enrolled. The IL-25-high group had a lower St. George's Respiratory Questionnaire score than others, and the TSLP-high group had a poorer exercise capacity than the TSLP-low group. There were no significant differences in the forced expiratory volume in 1 s (FEV1), the levels of Th2 inflammatory biomarkers, or the exacerbation histories between the two groups. The 3-year decline in FEV1 was not significantly affected by IL-25 or TSLP levels. In terms of 1-year exacerbation risk, individuals in the IL-25-high group were at lower risk for moderate-to-severe exacerbation than others. A high TSLP level was associated with a lower risk of severe exacerbation but only in the eosinophil-low group. Serum levels of IL-25 are negatively correlated with moderate-to-severe exacerbation risk in this cohort. A negative correlation between severe exacerbation risk and TSLP level was apparent only in the eosinophil-low group.

Methylxanthine Treatment in Patients Hospitalized for Acute Exacerbation of Chronic Obstructive Pulmonary Disease in China: A Real-World Study Using Propensity Score Matching Analysis

Background: Although medical guidelines discourage the use of methylxanthines in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD), they are still widely used in clinical practice. This study investigated the real-world use of methylxanthines in the management of AECOPD.

Methods: Patient data from the Acute exacerbation of Chronic obstructive pulmonary disease Using REgistry data (ACURE, NCT02657525) study database were screened. Enrolled patients were divided into treatment and control groups. Propensity score (PS) matching and Cox regression analyses were used to minimize confounding factors and determine the association between methylxanthine treatment and the length of stay (LOS).

Results: Among the 2088 eligible patients, 1,563 (74.9%) were in the methylxanthine treatment group. Patients treated with methylxanthines had more severe respiratory symptoms and worse lung function than those in the control group. Doxophylline was the most commonly used methylxanthine in both secondary and tertiary hospitals. After PS matching, 966 patients were equally divided into two groups. The LOS of patients in the two groups was similar [median: 8 days, interquartile range (IQR): 7–11 days, p = 0.730]. Patients in the treatment group (median: 8, IQR: 4–12) had a more significant decrease in the COPD Assessment Test score from admission to discharge than those in the control group (median: 6, IQR: 2–10, p &lt; 0.001). Among all matched patients, the LOS was not significantly associated with methylxanthine treatment [adjusted hazard ratio (HR): 1.02, 95% confidence intervals (CIs): 0.89–1.16]. However, in the subgroup analysis, methylxanthines were significantly associated with a short LOS in patients with blood eosinophil count &gt;4% (adjusted HR: 1.56, 95% CIs: 1.12–2.17).

Conclusion: This study revealed that methylxanthines, especially doxophylline, are widely used in China. Methylxanthines were effective in improving symptoms in AECOPD patients. Higher blood eosinophil count may be associated with a better efficacy of methylxanthine treatment.

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.

Eosinophil count and mortality risk in incident hemodialysis patients

BACKGROUND

Eosinophils are traditionally known as moderators of allergic reactions; however, they have now emerged as one of the principal immune-regulating cells as well as predictors of vascular disease and mortality in the general population. Although eosinophilia has been demonstrated in hemodialysis (HD) patients, associations of eosinophil count (EOC) and its changes with mortality in HD patients are still unknown.

METHODS

In 107 506 incident HD patients treated by a large dialysis organization during 2007-11, we examined the relationships of baseline and time-varying EOC and its changes (ΔEOC) over the first 3 months with all-cause mortality using Cox proportional hazards models with three levels of hierarchical adjustment.

RESULTS

Baseline median EOC was 231 (interquartile range 155-339) cells/μL and eosinophilia (>350 cells/μL) was observed in 23.4% of patients. There was a gradual increase in EOC over time after HD initiation with a median ΔEOC of 5.1 (IQR -53-199) cells/μL, which did not parallel the changes in white blood cell count. In fully adjusted models, mortality risk was highest in subjects with lower baseline and time-varying EOC (<100 cells/μL) and was also slightly higher in patients with higher levels (≥550 cells/μL), resulting in a reverse J-shaped relationship. The relationship of ΔEOC with all-cause mortality risk was also a reverse J-shape where both an increase and decrease exhibited a higher mortality risk.

CONCLUSIONS

Both lower and higher EOCs and changes in EOC over the first 3 months after HD initiation were associated with higher all-cause mortality in incident HD patients.

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

Background

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

Methods

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

Results

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

Conclusions

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

Trial registration

NCT04123028 at ClinicalTrials.gov.

Population Pharmacokinetic Modeling of Benralizumab in Adult and Adolescent Patients with Asthma

Introduction

Benralizumab, an interleukin-5 receptor alpha–directed cytolytic anti-eosinophil monoclonal antibody, was recently approved as add-on maintenance treatment for patients aged 12 years and older with uncontrolled asthma with eosinophilic inflammation.

Methods

Pharmacokinetic (PK) data from nine clinical trials for patients with asthma were pooled and analyzed to further characterize the PK of benralizumab and evaluate demographic covariate effects.

Results

Population modeling results demonstrated that the PK of benralizumab were dose-proportional across a wide dosage range and were adequately described by a two-compartment model with first-order absorption from the subcutaneous dosing site and a first-order elimination pathway from the central compartment. Following subcutaneous administration, the absorption half-life of benralizumab was 3.54 days, and the absolute bioavailability was 58.9%. Estimated clearance (CL; 0.291 L/day), central volume of distribution (V_c; 3.13 L), and peripheral volume of distribution (V_p; 2.52 L) were typical for therapeutic immunoglobulins. Elimination half-life was approximately 15.5 days for patients with asthma. Age, sex, race, liver function, renal function, baseline blood eosinophil count, anatomic injection site, and commonly used small-molecule drugs had no clinically relevant impact on benralizumab CL. Only body weight and antidrug antibodies (ADAs) were identified as relevant PK covariates. Power parameters (exponent) of body weight on CL, V_c, and V_p were 0.807, 0.803, and 0.528, respectively, and the presence of ADAs increased benralizumab CL by 124%.

Conclusions

Over 5–20 weeks, the PK of benralizumab were dose-proportional across a dosage range of 0.03–3 mg/kg intravenously and 2–200 mg subcutaneously administered every 4 weeks or every 8 weeks (first three doses every 4 weeks). Body weight and ADA status were identified as relevant PK covariates. Baseline eosinophil count, hepatic and renal functions, anatomical subcutaneous injection site, and commonly used small-molecule drugs had no impact on the PK of benralizumab.

Blood cell for the differentiation of airway inflammatory phenotypes in COPD exacerbations

Background

Measurement of sputum is frequently used to define airway inflammatory subtypes. The venous blood cell is a reliable and simple biomarker, may be used as an alternative procedure to reflect the subtypes. For the aim of verifying the hypothesis that venous blood cell can quantify sputum inflammatory cell to access the airway subtypes in chronic obstructive pulmonary disease of acute exacerbations (AECOPD) and to ascertain the accuracy of the blood cell biomarker.

Methods

This study evaluated 287 patients with COPD exacerbations and all four tests were performed on the same day, which are lung function test, bronchodilator reversibility test, sputum cell analysis and blood routine examination.

Results

There was a correlation between sputum eosinophils and blood eosinophils, blood cells derived ratios. There was a weaker relationship to neutrophils between sputum and blood. Sputum neutrophils had not any association with neutrophil/macrophage ratio (NMR) and eosinophil/lymphocyte ratio (ELR) in blood. Blood eosinophils percentage was predictive for eosinophilic COPD exacerbations with an area under the curve (AUC) of 0.672 (p = 0.012). The optimum cutpoint for blood eosinophils percentage was 0.55%. Blood eosinophils absolute count was also predictive sputum eosinophilia at 0.35 × 10⁹/L (AUC = 0.626, p = 0.025). ELR, eosinophil/monocyte ratio (EMR) and eosinophil/neutrophil ratio (ENR) in blood were higher in COPD exacerbations with mixed granulocytic and eosinophilic subtypes.

Conclusion

Eosinophils/neutrophils count parameters were relationship between blood and sputum. Eosinophils in blood and the ratios (ENR, EMR and ELR) may be utilized to assess eosinophilic airway inflammation in COPD exacerbations. Due to weak relationship and poor predictive ability, more researches should be required.

Clinical And Economic Burden Of Eosinophilic COPD In A Large Retrospective US Cohort

Purpose

We sought to describe clinical and economic outcomes for COPD patients by blood eosinophil (EOS) count.

Methods

This retrospective cohort study of COPD patients used data from the Practice Fusion electronic medical records (EMR) database linked to Symphony Health Solutions transactional pharmacy, medical, outpatient, and inpatient claims data to evaluate COPD-related and all-cause health care resource utilization and cost in the 12-month period following the date of each patient’s greatest recorded blood eosinophil count during the 27-month period from January 2014 to March 2016. A post-index moderate exacerbation was defined as an outpatient or emergency care visit for COPD and a prescription for oral corticosteroid and/or antibiotics within 10 days of the visit. Severe exacerbation was defined as an inpatient hospitalization with COPD as primary diagnosis.

Results

Of 48,090 EMR patients, 39,939 (83.1%) had a charge in the claims data both pre- and post-index (mean age 67.2 years, 58.3% female), 17,397 (43.6%) had EOS ≥220 cells/µL. Moderate and severe exacerbations were more frequent for patients with EOS≥220 cells/µL compared with those with EOS <220 cells/µL (moderate: 6.8% vs 6.1%, p<0.05; severe: 3.1% vs 2.5%, p<0.001). After adjustment for baseline clinical characteristics, each 100-unit increase in EOS count was associated with a significant 2.24% increase in total all-cause costs and 4.54% increase in total COPD-related costs (p<0.001 for both). COPD-related costs were significantly greater for patients with an EOS count of ≥220 cells/µL compared with those with EOS <220 cells/µL (p<0.001). These costs appear to have been driven by a greater percentage of patients in the ≥220 cells/µL cohort with COPD-related resource use including hospitalization, office visits, ambulatory procedures and pharmacy prescriptions.

Conclusion

COPD patients with EOS counts ≥220 cells/µL were more likely to have had moderate or severe exacerbations and greater cost of care than those with EOS <220 cells/µL.

Blood eosinophils as biomarkers of therapeutic response to chronic obstructive pulmonary disease: Still work in progress

Disease phenotyping is a key step towards an increasingly personalized approach to chronic obstructive pulmonary disease (COPD), leading to a more precise assessment, treatment and definition of disease outcomes. The search for biomarkers able to guide the identification of COPD phenotypes are of great importance for both researchers and clinicians. However, while several biomarkers of inflammation [e.g., peripheral blood eosinophils and fractional expired nitric oxide] have been identified and applied in asthma, none has been successfully linked to discrete clinical parameters of COPD such as exacerbations, natural progression, and treatment response or mortality risk. Recently, several studies have shown that blood eosinophils are a potential biomarker for patient subset stratification in COPD therapy. Here we reviewed the value of blood eosinophils in predicting the response of COPD patients to treatment.

Modulation of blood inflammatory markers by benralizumab in patients with eosinophilic airway diseases

Background

Benralizumab, a humanized, afucosylated, monoclonal antibody that targets interleukin-5 receptor α, depletes eosinophils and basophils by enhanced antibody-dependent cell-mediated cytotoxicity. It demonstrated efficacy for patients with moderate to severe asthma and, in a Phase IIa trial, for chronic obstructive pulmonary disease (COPD) with eosinophilic inflammation. We investigated effects of benralizumab 100 mg every 8 weeks (first three doses every 4 weeks) subcutaneous on blood inflammatory markers through proteomic and gene-expression analyses collected during two Phase II studies of patients with eosinophilic asthma and eosinophilic COPD.

Methods

Serum samples for proteomic analysis and whole blood for gene expression analysis were collected at baseline and 52 weeks (asthma study) or 32 weeks (COPD study) post-treatment. Proteomic analyses were conducted on a custom set of 90 and 147 Rules-Based Medicine analytes for asthma and COPD, respectively. Gene expression was profiled by Affymetrix Human Genome U133 plus 2 arrays (~ 54 K probes). Gene set variation analysis (GSVA) was used to determine transcriptomic activity of immune signatures. Treatment-related differences between analytes, genes, and gene signatures were analyzed for the overall population and for patient subgroups stratified by baseline blood eosinophil count (eosinophil-high [≥300 cells/μL] and eosinophil-low [< 300 cells/μL]) via t-test and repeated measures analysis of variance.

Results

Eosinophil chemokines eotaxin-1 and eotaxin-2 were significantly upregulated (false discovery rate [FDR] < 0.05) by approximately 2.1- and 1.4-fold in the asthma study and by 2.3- and 1.7-fold in the COPD study following benralizumab treatment. Magnitude of upregulation of these two chemokines was greater for eosinophil-high patients than eosinophil-low patients in both studies. Benralizumab was associated with significant reductions (FDR < 0.05) in expression of genes associated with eosinophils and basophils, such as CLC, IL-5Rα, and PRSS33; immune-signaling complex genes (FCER1A); G-protein–coupled receptor genes (HRH4, ADORA3, P2RY14); and further immune-related genes (ALOX15 and OLIG2). The magnitude of downregulation of gene expression was greater for eosinophil-high than eosinophil-low patients. GSVA on immune signatures indicated significant treatment reductions (FDR < 0.05) in eosinophil-associated signatures.

Conclusions

Benralizumab is highly selective, modulating blood proteins or genes associated with eosinophils or basophils. Modulated protein and gene expression patterns are most prominently altered in eosinophil-high vs. eosinophil-low patients.

Trial registration

NCT01227278 and NCT01238861.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0968-8) contains supplementary material, which is available to authorized users.

Comparative effectiveness of LABA-ICS versus LAMA as initial treatment in COPD targeted by blood eosinophils: a population-based cohort study

BACKGROUND

Long-acting β₂ agonists (LABAs) and long-acting muscarinic antagonists (LAMAs) are the recommended initial maintenance treatment for chronic obstructive pulmonary disease (COPD), with almost all LABAs dispensed in fixed combination with inhaled corticosteroids (LABA-ICS). We compared the effectiveness and safety of LABA-ICS versus LAMA treatment initiation as a function of blood eosinophilia, a potential biomarker of ICS effectiveness, in a real-world setting.

METHODS

In this population-based cohort study, we identified a cohort of patients with COPD initiating treatment with a LAMA or LABA-ICS during 2002-15, age 55 years or older, from the UK's Clinical Practice Research Datalink. We excluded patients who initiated treatment with both bronchodilators on the same date. All patients required at least 1 year of medical history and a measure of blood eosinophil concentration before cohort entry, defined by the date of the first cohort-defining bronchodilator prescription. Patients initiating a LAMA were matched on high-dimensional propensity scores with patients initiating a LABA-ICS. They were followed up for 1 year for the occurrence of a moderate or severe COPD exacerbation and for severe pneumonia. Sensitivity analyses included, among others, repeating the analysis among patients with two blood eosinophil concentration measures and stratification by concurrent asthma and previous exacerbations.

FINDINGS

The base cohort included 539 643 patients with a prescription for LABAs or LAMAs from Jan 1, 2002, to Dec 31, 2015, of whom 18 500 were initiated on LABA-ICS and 13 870 on LAMAs. Propensity score analysis resulted in 12 366 initiators of LAMAs (mainly tiotropium) matched to 12 366 initiators of LABA-ICS. The hazard ratio (HR) of COPD exacerbation associated with LABA-ICS initiation, relative to LAMA initiation, was 0·95 (95% CI 0·90-1·01). In patients with blood eosinophil concentrations of less than 2% of white blood cell count, the HR was 1·03 (95% CI 0·93-1·13) and for those with eosinophil concentrations of 2-4%, the HR was 1·00 (0·91-1·10). For patients with eosinophil concentrations of more than 4%, the HR was 0·79 (0·70-0·88). The incidence of pneumonia increased with LABA-ICS initiation (HR 1·37 [95% CI 1·17-1·60]) and was similar across all eosinophil concentrations. Sensitivity analyses were consistent with these findings, but the incidence of exacerbation with LABA-ICS among the 2766 (11%) of all 24 732 patients with two or more COPD exacerbations during the baseline year was marginally lower (HR 0·87 [95% CI 0·79-0·97]).

INTERPRETATION

In this real-world, clinical practice, observational study, initial COPD treatment with LABA-ICS inhalers was only more effective than with LAMAs in patients with high blood eosinophil concentrations (>4%) or counts (>300 cells per μL) and possibly in frequent exacerbators. Because of the increased risk of pneumonia associated with the ICS component, initiation with a LAMA should be preferred in patients with blood eosinophil concentrations of less than 4%.

FUNDING

Canadian Institutes of Health Research, Canadian Foundation for Innovation.

Blood eosinophils and inhaled corticosteroids in patients with COPD: systematic review and meta-analysis

Background

COPD is a highly heterogeneous disease. Potential biomarkers to identify patients with COPD who will derive the greatest benefit from inhaled corticosteroid (ICS) treatment are needed. Blood eosinophil count can serve as a predictive biomarker for the efficacy of ICS treatment. The aim of this systematic review and meta-analysis was to assess whether a blood eosinophil count of ≥2% in patients undergoing ICS therapy was associated with a greater reduction in COPD exacerbation rate and pneumonia incidence.

Materials and methods

An electronic search was performed using the keywords "COPD", "eosinophil", and "clinical trial" in the PubMed and EMBASE databases to retrieve articles, up to 2017, relevant to our focus. Data were extracted, and a meta-analysis was conducted using RevMan 5 (version 5.3.5).

Results

Five studies comprising 12,496 patients with moderate-to-very severe COPD were included. At baseline, 60% of the patients had ≥2% blood eosinophils. Our meta-analysis showed a 17% reduction in exacerbation of moderate/severe COPD in patients with ≥2% blood eosinophils undergoing ICS therapy compared to the non-ICS/ICS withdrawal/placebo group. The difference between the two types of treatment was significant (risk ratio [RR], 0.816; 95% CI, 0.67-0.99; P=0.03). Furthermore, the risk of pneumonia-related events was significantly increased in the subgroup with eosinophil count ≥2% undergoing ICS-containing treatments (RR, 1.969; 95% CI, 1.369-2.833; P<0.001). There was no significant difference in the subgroup with eosinophil count <2% (RR, 1.29; 95% CI, 0.888-1.879; P<0.181).

Conclusion

The results of our meta-analysis suggest that the 2% threshold for blood eosinophils could accurately predict ICS treatment response in patients with COPD, but increased the risk of pneumonia.

Health care resource utilization and cost for asthma patients regularly treated with oral corticosteroids - a Swedish observational cohort study (PACEHR)

BACKGROUND

Patients with severe uncontrolled asthma may receive oral corticosteroid (OCS) treatment regularly. The present study investigated the health care resource utilization and cost in regularly OCS treated Swedish asthma patients.

METHODS

Primary care medical records data were linked to data from Swedish national health registries. Patients ≥18 years with a drug claim for obstructive pulmonary diseases during 2007-2009 (index date) and a prior asthma diagnosis, were classified by their OCS claims during the 12-months' post index period: regular OCS equals ≥5 mg per day; periodic OCS less than 5 mg per day; or non-OCS users. Cost of asthma- and OCS-morbidity-related health care resource utilization were calculated.

RESULTS

A total of 15,437 asthma patients (mean age 47.8, female 62.6%), whereof 223 (1.44%) were regular OCS users, 3054 (19.7%) were periodic, and 12,160 (78.7%) were non-OCS users. Regular OCS users were older and more often females, had lower lung function, greater eosinophil count and more co-morbidities at baseline compared with the other groups. Age-adjusted annual total health care cost was three-times greater in the regular OCS group (€5615) compared with the non-OCS users (€1980) and twice as high as in the periodic OCS group (€2948). The major cost driver in the non-OCS and periodic OCS groups were primary care consultations, whereas inpatient costs were the major cost driver in the regular OCS group. The asthma related costs represented 10-12% of the total cost in all three groups.

CONCLUSION

In this real-life asthma study in Sweden, the total yearly cost of health care resource utilization for a regular OCS user was three times greater than for a patient with no OCS use, indicating substantial economic and health care burden for asthma patients on regular oral steroid treatment.

Blood Eosinophil Count and Metabolic, Cardiac and Pulmonary Outcomes: A Mendelian Randomization Study

Blood eosinophil count is associated with a variety of common complex outcomes in epidemiological observation. The aim of this study was to explore the causal association between determined blood eosinophil count and 20 common complex outcomes (10 metabolic, 6 cardiac, and 4 pulmonary). Through Mendelian randomization, we investigated genetic evidence for the genetically determined eosinophil in association with each outcomes using individual-level LifeLines cohort data (n = 13,301), where a weighted eosinophil genetic risk score comprising five eosinophil associated variants was created. We further examined the associations of the genetically determined eosinophil with those outcomes using summary statistics obtained from genome-wide association study consortia (6 consortia and 14 outcomes). Blood eosinophil count, by a 1-SD genetically increased, was not statistically associated with common complex outcomes in the LifeLines. Using the summary statistics, we showed that a higher genetically determined eosinophil count had a significant association with lower odds of obesity (odds ratio (OR) 0.81, 95% confidence interval (CI) [0.74, 0.89]) but not with the other traits and diseases. To conclude, an elevated eosinophil count is unlikely to be causally associated to higher risk of metabolic, cardiac, and pulmonary outcomes. Further studies with a stronger genetic risk score for eosinophil count may support these results.

Association of sputum and blood eosinophil concentrations with clinical measures of COPD severity: an analysis of the SPIROMICS cohort

BACKGROUND

Increased concentrations of eosinophils in blood and sputum in chronic obstructive pulmonary disease (COPD) have been associated with increased frequency of exacerbations, reduced lung function, and corticosteroid responsiveness. We aimed to assess whether high eosinophil concentrations in either sputum or blood are associated with a severe COPD phenotype, including greater exacerbation frequency, and whether blood eosinophils are predictive of sputum eosinophils.

METHODS

We did a multicentre observational study analysing comprehensive baseline data from SPIROMICS in patients with COPD aged 40-80 years who had a smoking history of at least 20 pack-years, recruited from six clinical sites and additional subsites in the USA between Nov 12, 2010, and April 21, 2015. Inclusion criteria for this analysis were SPIROMICS baseline visit data with complete blood cell counts and, in a subset, acceptable sputum counts. We stratified patients on the basis of blood and sputum eosinophil concentrations and compared their demographic characteristics, as well as results from questionnaires, clinical assessments, and quantitative CT (QCT). We also analysed whether blood eosinophil concentrations reliably predicted sputum eosinophil concentrations. This study is registered with ClinicalTrials.gov (NCT01969344).

FINDINGS

Of the 2737 patients recruited to SPIROMICS, 2499 patients were smokers and had available blood counts, and so were stratified by mean blood eosinophil count: 1262 patients with low (<200 cells per μL) and 1237 with high (≥200 cells per μL) blood eosinophil counts. 827 patients were eligible for stratification by mean sputum eosinophil percentage: 656 with low (<1·25%) and 171 with high (≥1·25%) sputum eosinophil percentages. The high sputum eosinophil group had significantly lower median FEV1 percentage predicted than the low sputum eosinophil group both before (65·7% [IQR 51·8-81·3] vs 75·7% [59·3-90·2], p<0·0001) and after (77·3% [63·1-88·5] vs 82·9% [67·8-95·9], p=0·001) bronchodilation. QCT density measures for emphysema and air trapping were significantly higher in the high sputum eosinophil group than the low sputum eosinophil group. Exacerbations requiring corticosteroids treatment were more common in the high versus low sputum eosinophil group (p=0·002). FEV1 percentage predicted was significantly different between low and high blood eosinophil groups, but differences were less than those observed between the sputum groups. The high blood eosinophil group had slightly increased airway wall thickness (0·02 mm difference, p=0·032), higher St George Respiratory Questionnaire symptom scores (p=0·037), and increased wheezing (p=0·018), but no evidence of an association with COPD exacerbations (p=0·35) or the other indices of COPD severity, such as emphysema measured by CT density, COPD assessment test scores, Body-mass index, airflow Obstruction, Dyspnea, and Exercise index, or Global Initiative for Chronic Obstructive Lung Disease stage. Blood eosinophil counts showed a weak but significant association with sputum eosinophil counts (receiver operating characteristic area under the curve of 0·64, p<0·0001), but with a high false-discovery rate of 72%.

INTERPRETATION

In a large, well characterised cohort of former and current smoking patients with a broad range of COPD severity, high concentrations of sputum eosinophils were a better biomarker than high concentrations of blood eosinophils to identify a patient subgroup with more severe disease, more frequent exacerbations, and increased emphysema by QCT. Blood eosinophils alone were not a reliable biomarker for COPD severity or exacerbations, or for sputum eosinophils. Clinical trials targeting eosinophilic inflammation in COPD should consider assessing sputum eosinophils.

FUNDING

National Institutes of Health, and National Heart, Lung, and Blood Institute.

Eosinophils in COPD: just another biomarker?

Eosinophils are innate immune cells that, under certain conditions, can be recruited to the lungs, where they have an incompletely understood role in health and disease. Eosinophils have been found in the airways, tissues, and circulation of patients with COPD, during both stable disease and exacerbations. Epidemiological studies and post-hoc analyses of clinical trials of corticosteroid treatment for COPD have shown that the blood eosinophil count is associated with the risk of COPD exacerbations, mortality, decline in FEV₁, and response to both inhaled and systemic corticosteroids. Further studies are urgently needed to explore the contribution of eosinophils to the mechanism of disease in COPD and to identify their association with levels of clinical risk. In this review, we explore the role of the eosinophil as a biomarker and mediator of disease in COPD.

Lifetime Smoking History and Cause-Specific Mortality in a Cohort Study with 43 Years of Follow-Up

BACKGROUND

In general, smoking increases the risk of mortality. However, it is less clear how the relative risk varies by cause of death. The exact impact of changes in smoking habits throughout life on different mortality risks is less studied.

METHODS

We studied the impact of baseline and lifetime smoking habits, and duration of smoking on the risk of all-cause mortality, mortality of cardiovascular diseases (CVD), chronic obstructive pulmonary disease (COPD), any cancer and of the four most common types of cancer (lung, colorectal, prostate, and breast cancer) in a cohort study (Vlagtwedde-Vlaardingen 1965-1990, with a follow-up on mortality status until 2009, n = 8,645). We used Cox regression models adjusted for age, BMI, sex, and place of residence. Since previous studies suggested a potential effect modification of sex, we additionally stratified by sex and tested for interactions. In addition, to determine which cause of death carried the highest risk we performed competing-risk analyses on mortality due to CVD, cancer, COPD and other causes.

RESULTS

Current smoking (light, moderate, and heavy cigarette smoking) and lifetime persistent smoking were associated with an increased risk of all-cause, CVD, COPD, any cancer, and lung cancer mortality. Higher numbers of pack years at baseline were associated with an increased risk of all-cause, CVD, COPD, any cancer, lung, colorectal, and prostate cancer mortality. Males who were lifetime persistent pipe/cigar smokers had a higher risk of lung cancer [HR (95% CI) = 7.72 (1.72-34.75)] as well as all-cause and any cancer mortality. A longer duration of smoking was associated with a higher risk of COPD, any and lung cancer [HR (95% CI) = 1.06 (1.00-1.12), 1.03 (1.00-1.06) and 1.10 (1.03-1.17) respectively], but not with other mortality causes. The competing risk analyses showed that ex- and current smokers had a higher risk of cancer, CVD, and COPD mortality compared to all other mortality causes. In addition, heavy smokers had a higher risk for COPD mortality compared to cancer, and CVD mortality.

CONCLUSION

Our study indicates that lifetime numbers of cigarettes smoked and the duration of smoking have different impacts for different causes of mortality. Moreover, our findings emphasize the importance of smoking-related competing risks when studying the smoking-related cancer mortality in a general population and that smoking cessation immediately effectively reduces the risk of all-cause and any cancer mortality.

Revisiting the Dutch hypothesis

The Dutch hypothesis was first articulated in 1961, when many novel and advanced scientific techniques were not available, such as genomics techniques for pinpointing genes, gene expression, lipid and protein profiles, and the microbiome. In addition, computed tomographic scans and advanced analysis techniques to dissect (small) airways disease and emphysema were not available. At that time, the group of researchers under the visionary guidance of Professor N. G. M. Orie put forward that both genetic and environmental factors can determine whether one would have airway obstructive diseases, such as asthma and chronic obstructive pulmonary disease (COPD). Moreover, they stipulated that the phenotype of obstructive airway disease could be affected by sex and changes with aging. Orie and colleagues' call to carefully phenotype patients with obstructive airways diseases has been adopted by many current researchers in an attempt to determine the heterogeneity of both asthma and COPD to better define these diseases and optimize their treatment. The founders of the Dutch hypothesis were far ahead of their time, and we can learn from their insights. We should fully characterize all patients in our clinical practice and not just state that they have asthma, COPD, or asthma and COPD overlap syndrome. This detailed phenotyping can help in understanding these obstructive airway diseases and provide guidance for disease management.

The utility of inflammatory markers to predict readmissions and mortality in COPD cases with or without eosinophilia

BACKGROUND

COPD exacerbations requiring hospitalization increase morbidity and mortality. Although most COPD exacerbations are neutrophilic, approximately 10%-25% of exacerbations are eosinophilic.

AIM

We aimed to evaluate mortality and outcomes of eosinophilic and non-eosinophilic COPD exacerbations and identify new biomarkers that predict survival.

METHODS

A retrospective observational cohort study was carried out in a tertiary teaching hospital from January 1, 2014 to November 1, 2014. All COPD patients hospitalized with exacerbations were enrolled in the study at their initial hospitalization and followed-up for 6 months after discharge. Electronic data were collected from the hospital database. Subjects' characteristics, hemogram parameters, CRP levels, neutrophil-to-lymphocyte ratio (NLR), platelet-to-mean platelet volume ratio on admission and discharge, length of hospital stay (days), readmissions, and mortality were recorded. Patients were grouped according to peripheral blood eosinophil (PBE) levels: Group 1, >2% PBE, eosinophilic; Group 2, non-eosinophilic ≤2%. Patient survival after hospital discharge was evaluated by Kaplan-Meier survival analysis.

RESULTS

A total of 1,704 patients hospitalized with COPD exacerbation were included. Approximately 20% were classified as eosinophilic. Six-month mortality was similar in eosinophilic and non-eosinophilic groups (14.2% and 15.2%, respectively); however, the hospital stay length and readmission rate were longer and higher in the non-eosinophilic group (P<0.001 and P<0.01, respectively). CRP and NLR were significantly higher in the non-eosinophilic group (both P<0.01). The platelet-to-mean platelet volume ratio was not different between the two groups. Cox regression analysis showed that survival was negatively influenced by elevated CRP (P<0.035) and NLR (P<0.001) in the non-eosinophilic group.

CONCLUSION

Non-eosinophilic patients with COPD exacerbations with high CRP and NLR values had worse outcomes than eosinophilic patients. PBE and NLR can be helpful markers to guide treatment decisions.

BMI and lifetime changes in BMI and cancer mortality risk

Body Mass Index (BMI) is known to be associated with cancer mortality, but little is known about the link between lifetime changes in BMI and cancer mortality in both males and females. We studied the association of BMI measurements (at baseline, highest and lowest BMI during the study-period) and lifetime changes in BMI (calculated over different time periods (i.e. short time period: annual change in BMI between successive surveys, long time period: annual change in BMI over the entire study period) with mortality from any cancer, and lung, colorectal, prostate and breast cancer in a large cohort study (n=8,645. Vlagtwedde-Vlaardingen, 1965-1990) with a follow-up on mortality status on December 31^st 2008. We used multivariate Cox regression models with adjustments for age, smoking, sex, and place of residence. Being overweight at baseline was associated with a higher risk of prostate cancer mortality (hazard ratio (HR) =2.22; 95% CI 1.19-4.17). Obesity at baseline was associated with a higher risk of any cancer mortality [all subjects (1.23 (1.01-1.50)), and females (1.40 (1.07-1.84))]. Chronically obese females (females who were obese during the entire study-period) had a higher risk of mortality from any cancer (2.16 (1.47-3.18), lung (3.22 (1.06-9.76)), colorectal (4.32 (1.53-12.20)), and breast cancer (2.52 (1.15-5.54)). We found no significant association between long-term annual change in BMI and cancer mortality risk. Both short-term annual increase and decrease in BMI were associated with a lower mortality risk from any cancer [all subjects: (0.67 (0.47-0.94)) and (0.73 (0.55-0.97)), respectively]. In conclusion, a higher BMI is associated with a higher cancer mortality risk. This study is the first to show that short-term annual changes in BMI were associated with lower mortality from any type of cancer.

Objective allergy markers and risk of cancer mortality and hospitalization in a large population-based cohort

Purpose

There are indications that a history of allergy may offer some protection against cancer. We studied the relation of three objectively determined allergy markers with cancer mortality and hospitalization risk.

Methods

Associations between three allergy markers (number of peripheral blood eosinophil counts, skin test positivity, and serum total IgE) with mortality and hospitalization from any type and four common types of cancer (lung, colorectal, prostate, and breast cancer) were assessed in the Vlagtwedde–Vlaardingen cohort (1965–1990), with follow-up of mortality until 31 December 2008. Hospitalization data were available since 1 January 1995.

Results

There were no significant associations between objective allergy markers and cancer mortality or hospitalization. We found several associations in specific subgroups. A higher number of eosinophils was associated with a decreased risk of colorectal cancer mortality in ever smokers HR (95 % CI) = 0.61 (0.45–0.83) and in males 0.59 (0.42–0.83); however, no overall association was observed 0.84 (0.64–1.09). Skin test positivity was associated with a decreased risk of any cancer mortality only among females 0.59 (0.38–0.91) and showed no overall association 0.83 (0.67–1.04). Serum total IgE levels were associated with an increased risk of lung cancer mortality among females 4.64 (1.04–20.70), but with a decreased risk of cancer hospitalization in ever smokers 0.77 (0.61–0.97) and males 0.72 (0.55–0.93); however, no overall associations were observed [mortality 0.99 (0.79–1.25), and hospitalization 0.86 (0.71–1.04)].

Conclusions

We found no associations between objective allergy markers and cancer in the total population. However, skin test positivity and a high number of eosinophils were associated with a reduced risk to die of cancer in specific subgroups. Hence, it seems important to study specific subgroups defined by gender and smoking habits in order to identify allergy markers of predictive value for cancer mortality.

Electronic supplementary material

The online version of this article (doi:10.1007/s10552-014-0489-9) contains supplementary material, which is available to authorized users.

Serum uric acid levels and cancer mortality risk among males in a large general population-based cohort study

Purpose

Serum uric acid (SUA) has antioxidant capacities and therefore may protect against the development of cancer. Few epidemiological studies have tested this hypothesis, and findings were inconsistent.

Methods

We studied the association between SUA levels and mortality due to any type of cancer, and three common types of cancer among males (lung, colorectal, and prostate cancer) in the general population-based Vlagtwedde–Vlaardingen cohort with 38 years of follow-up and 8 surveys (total number of males = 4,350). Of 1,823 males with data available on SUA, 254 (13.9 %) died due to any cancer (lung n = 75 (4.1 %), colorectal n = 27 (1.5 %), and prostate cancer n = 23 (1.3 %), assessed on 31 December 2008). SUA, cholesterol, and triglyceride were measured in males during the surveys in 1970, 1972, and 1973. We analyzed the association between cancer mortality risk and SUA level both as continuous variable and as tertiles: lowest <5 mg/dl (reference), middle 5–5.8 mg/dl, and highest >5.8 mg/dl, using multivariate Cox regression with adjustment for age, smoking (pack years), and body mass index.

Results

Higher levels of SUA were associated with a lower risk of mortality from any cancer [HR (95 % CI) = 0.85 (0.73–0.97)]. SUA levels in the highest tertile (>5.8 mg/dl) were associated with a lower risk of mortality from any cancer [0.68 (0.48–0.97)]. Additional adjustment for serum total cholesterol and triglyceride levels did not change the results.

Conclusions

Our study indicates that elevated SUA levels may protect against cancer mortality.

GST-omega genes interact with environmental tobacco smoke on adult level of lung function

BACKGROUND

Lung growth in utero and lung function loss during adulthood can be affected by exposure to environmental tobacco smoke (ETS). The underlying mechanisms have not been fully elucidated. Both ETS exposure and single nucleotide polymorphisms (SNPs) in Glutathione S-Transferase (GST) Omega genes have been associated with the level of lung function. This study aimed to assess if GSTO SNPs interact with ETS exposure in utero and during adulthood on the level of lung function during adulthood.

METHODS

We used cross-sectional data of 8,128 genotyped participants from the LifeLines cohort study. Linear regression models (adjusted for age, sex, height, weight, current smoking, ex-smoking and packyears smoked) were used to analyze the associations between in utero, daily and workplace ETS exposure, GSTO SNPs, the interaction between ETS and GSTOs, and level of lung function (FEV(1), FEV(1)/FVC). Since the interactions between ETS and GSTOs may be modified by active tobacco smoking we additionally assessed associations in never and ever smokers separately. A second sample of 5,308 genotyped LifeLines participants was used to verify our initial findings.

RESULTS

Daily and workplace ETS exposure was associated with significantly lower FEV(1)levels. GSTO SNPs (recessive model) interacted with in utero ETS and were associated with higher levels of FEV(1), whereas the interactions with daily and workplace ETS exposure were associated with lower levels of FEV(1), effects being more pronounced in never smokers. The interaction of GSTO2 SNP rs156697 with in utero ETS associated with a higher level of FEV(1) was significantly replicated in the second sample. Overall, the directions of the interactions of in utero and workplace ETS exposure with the SNPs found in the second (verification) sample were in line with the first sample.

CONCLUSIONS

GSTO genotypes interact with in utero and adulthood ETS exposure on adult lung function level, but in opposite directions.

Eosinophils as diagnostic tools in chronic lung disease

Chronic lung diseases are very common and form a major threat to large proportions of the population with increased morbidity and mortality. Asthma is one of the most common eosinophilic airway diseases. However, there is growing evidence that eosinophilic inflammation is also important in subgroups of patients with chronic obstructive pulmonary disease, chronic cough and idiopathic pulmonary fibrosis. Several studies have shown that sputum eosinophilia is associated with a favorable response to treatment of corticosteroids in both asthma and chronic obstructive pulmonary disease, and tailored strategies aimed to normalize sputum eosinophils have resulted in a significant reduction in exacerbation rates. In this article, the authors review the role of eosinophilic inflammation in the diagnosis and management of chronic respiratory diseases.

Blood eosinophils to direct corticosteroid treatment of exacerbations of chronic obstructive pulmonary disease: a randomized placebo-controlled trial

RATIONALE

Exacerbations of chronic obstructive pulmonary disease (COPD) and responses to treatment are heterogeneous.

OBJECTIVES

Investigate the usefulness of blood eosinophils to direct corticosteroid therapy during exacerbations.

METHODS

Subjects with COPD exacerbations were entered into a randomized biomarker-directed double-blind corticosteroid versus standard therapy study. Subjects in the standard arm received prednisolone for 2 weeks, whereas in the biomarker-directed arm, prednisolone or matching placebo was given according to the blood eosinophil count biomarker. Both study groups received antibiotics. Blood eosinophils were measured in the biomarker-directed and standard therapy arms to define biomarker-positive and -negative exacerbations (blood eosinophil count > and ≤ 2%, respectively). The primary outcome was to determine noninferiority in health status using the chronic respiratory questionnaire (CRQ) and in the proportion of exacerbations associated with a treatment failure between subjects allocated to the biomarker-directed and standard therapy arms.

MEASUREMENTS AND MAIN RESULTS

There were 86 and 80 exacerbations in the biomarker-directed and standard treatment groups, respectively. In the biomarker-directed group, 49% of the exacerbations were not treated with prednisolone. CRQ improvement after treatment in the standard and biomarker-directed therapy groups was similar (0.8 vs. 1.1; mean difference, 0.3; 95% confidence interval, 0.0-0.6; P = 0.05). There was a greater improvement in CRQ in biomarker-negative exacerbations given placebo compared with those given prednisolone (mean difference, 0.45; 95% confidence interval, 0.01-0.90; P = 0.04). In biomarker-negative exacerbations, treatment failures occurred in 15% given prednisolone and 2% of those given placebo (P = 0.04).

CONCLUSIONS

The peripheral blood eosinophil count is a promising biomarker to direct corticosteroid therapy during COPD exacerbations, but larger studies are required.

Acute exacerbations of chronic obstructive pulmonary disease: identification of biologic clusters and their biomarkers

RATIONALE

Exacerbations of chronic obstructive pulmonary disease (COPD) are heterogeneous with respect to inflammation and etiology.

OBJECTIVES

Investigate biomarker expression in COPD exacerbations to identify biologic clusters and determine biomarkers that recognize clinical COPD exacerbation phenotypes, namely those associated with bacteria, viruses, or eosinophilic airway inflammation.

METHODS

Patients with COPD were observed for 1 year at stable and exacerbation visits. Biomarkers were measured in sputum and serum. Viruses and selected bacteria were assessed in sputum by polymerase chain reaction and routine diagnostic bacterial culture. Biologic phenotypes were explored using unbiased cluster analysis and biomarkers that differentiated clinical exacerbation phenotypes were investigated.

MEASUREMENTS AND MAIN RESULTS

A total of 145 patients (101 men and 44 women) entered the study. A total of 182 exacerbations were captured from 86 patients. Four distinct biologic exacerbation clusters were identified. These were bacterial-, viral-, or eosinophilic-predominant, and a fourth associated with limited changes in the inflammatory profile termed “pauciinflammatory.” Of all exacerbations, 55%, 29%, and 28% were associated with bacteria, virus, or a sputum eosinophilia. The biomarkers that best identified these clinical phenotypes were sputum IL-1β, 0.89 (area under receiver operating characteristic curve) (95% confidence interval [CI], 0.83–0.95); serum CXCL10, 0.83 (95% CI, 0.70–0.96); and percentage peripheral eosinophils, 0.85 (95% CI, 0.78–0.93), respectively.

CONCLUSIONS

The heterogeneity of the biologic response of COPD exacerbations can be defined. Sputum IL-1β, serum CXCL10, and peripheral eosinophils are biomarkers of bacteria-, virus-, or eosinophil-associated exacerbations of COPD. Whether phenotype-specific biomarkers can be applied to direct therapy warrants further investigation.

The prevalence and meaning of eosinophilia in renal diseases on a nephrology consultation service

BACKGROUND

In recent years, we have come to understand that the eosinophil is more than the end point in clearance of parasitic infection or a maladaptive response to asthma and allergic reactions. Since eosinophilia has been reported to be common in renal diseases, we thought that an evaluation of the associations of eosinophilia on a renal consultation service would add some value to the understanding of their role in renal disease.

METHODS

This was a prospective cross-sectional study of 1339 consecutive patients referred to the nephrology service after hospitalization who were evaluated for the relationship of the amount of serum eosinophils to their diagnosis, gender, age and the presence of autoimmune disease, cancer, infection, liver disease, pleural effusions, allergies and use of prednisone, beta-blockers or beta agonists, in addition to the total white blood count, urine protein, serum concentration creatinine and phosphorus levels and estimated glomerular filtration rate.

RESULTS

The presence of vascular disease correlated the most strongly with increased eosinophil count (partial correlation coefficient, r = 0.18, P = 0.006), followed by pleural effusions (r = 0.17, P = 0.001), while total white cell count (r = -0.18, P = 0.008) and administration of beta-blockers (r = -0.13, P = 0.047) demonstrated significant inverse correlations and the presence of autoimmune disease, cancer, allergies, proteinuria and serum phosphorus concentration demonstrated no significant correlation.

CONCLUSION

There are multiple associations with increased eosinophil counts in patients seen on a nephrology consultant service; however, their presence appears less often in association with allergies or uremia and more often with vascular disease.

Nested case-control study on associations between lung function, smoking and mortality in Japanese population

OBJECTIVES

Only a few long-term follow-up studies with a focus on the association between lung function and mortality in the Japanese population have been undertaken. In this study, we examined the associations of lung function, smoking and the results of allergy skin tests with mortality in a longitudinal study of the Japanese population.

METHODS

Baseline measurements were performed on residents of Fukui, Japan in 1972, and a follow-up survey was conducted in 2002. By employing a nested case-control design, 596 cases (deaths) and 596 age and sex-matched controls (survivals) were selected. Lung function was assessed using forced vital capacity (FVC) expressed as the normal percent predicted (FVC %pred) and the ratio of forced expiratory volume in 1 second (FEV(1)) to FVC (FEV(1)/FVC). Allergy skin tests were performed with extracts of house dust, candidia and mixed fungal samples (bronchomycosis). The Brinkman index was used to assess smoking intensity. The Cox proportional hazards model was used to evaluate whether lung function was associated with mortality after adjustment for other potential confounding variables.

RESULTS

Those categorized into the first- or second-lowest quartile of FVC %pred had a higher mortality [hazard ratios (HRs) and 95% confidence intervals (CIs): 2.01 (1.26-3.19) and 1.84 (1.11-3.05)], respectively. On top of these, heavy smoking (BI≥400) was associated with a higher mortality [HR and 95% CI: 1.73 (1.18-2.53)]. There were only weak of associations between the results of allergy skin tests and mortality.

CONCLUSIONS

These results suggest that FVC %pred of lung function and smoking can serve as long-term independent predictors of mortality.

Factors Predicting Outcome in a Cohort of Patients With Atherosclerotic Renal Artery Disease Diagnosed by Magnetic Resonance Angiography

BACKGROUND

Atherosclerotic renal artery disease increasingly is recognized as a cause of chronic kidney disease and associated with high morbidity and mortality. We investigated factors predicting patient and renal survival in a cohort of patients with atherosclerotic renal artery disease diagnosed by means of magnetic resonance angiography (MRA).

METHODS

We retrospectively analyzed a cohort of patients attending our unit in whom atherosclerotic renal artery disease was identified by means of MRA from 1998 to 2001. One hundred nine patients were followed up for a median of 2.3 years. Baseline clinical and laboratory data were assessed as predictors of outcome by using multivariate Cox proportional hazards analysis.

RESULTS

Seventeen patients (16%) required dialysis and 37 patients (34%) died during a median follow-up of 841 days (interquartile range, 326 to 1,206). On multivariate Cox proportional hazards analysis, increased peripheral-blood eosinophil count (hazard ratio, 3.39; 95% confidence interval [CI], 1.45 to 7.88; P = 0.0097), creatinine clearance (hazard ratio, 0.97; 95% CI, 0.94 to 0.99; P = 0.0128), and peripheral arterial disease (hazard ratio, 2.09; 95% CI, 1.04 to 4.18; P = 0.0371) were associated with subsequent death. Only creatinine clearance (hazard ratio, 0.91; 95% CI, 0.87 to 0.96; P = 0.0004) was associated with the need for dialysis. There was no association between eosinophil count and other markers of inflammation. Severity of atherosclerotic renal artery disease was not associated independently with either the need for dialysis or death.

CONCLUSION

An increased peripheral-blood eosinophil count predicts patient survival in those with atherosclerotic renal artery disease at the time of diagnosis. This novel risk factor may help identify a group of patients who could benefit from intensive medical therapy by using an assay readily available to most clinicians worldwide.

Effects of asthma on cell components in peripheral blood among smokers and non-smokers

BACKGROUND

Eosinophils play a central role in asthma, but the interplay of the effects of smoking, eosinophils and asthma remains unclear.

OBJECTIVE

The primary objective of our study was to investigate the extent to which smoking modifies the effect of asthma on circulating eosinophils, CD4+ and CD8+ T cell counts.

METHODS

Data were collected semiannually between 1987 and 1994 from HIV-negative participants in the Multicenter AIDS Cohort Study. Asthma was defined by a questionnaire at baseline as a self-report of diagnosed asthma. A total of 1420 blood samples from 197 asthmatics and 15 822 from 1997 non-asthmatics were collected.

RESULTS

Eosinophil levels were higher in asthmatics (28% of asthmatics had eosinophils >/=4% and 16% of non-asthmatics) regardless of smoking history, but smoking modified the association between eosinophils and asthma. Namely, the odds ratios for eosinophils being >/=4% in asthmatics to non-asthmatics decreased from 2.7 (95% CI: 2.0, 3.6) in never, to 2.1 (1.4, 3.1) in former, and to 1.5 (0.9, 2.3) in current smokers. Cross-sectional and longitudinal analyses coherently showed that smoking increased eosinophils in non-asthmatics, but the converse was true for asthmatics. In contrast, no differences in peripheral blood T cell counts between asthmatics and non-asthmatics were observed.

CONCLUSION

Under the established link between increased eosinophils and asthma, these data indicate that smoking modified this relationship. This finding suggests that smoking plays a different immunological role in asthmatics and non-asthmatics.

Spirometric abnormalities associated with chronic bronchitis, asthma, and airway hyperresponsiveness among boilermaker construction workers

STUDY OBJECTIVES

In a 2-year longitudinal study of boilermaker construction workers, we found a significant association between working at oil-fired, coal-fired, and gas-fired industries during the past year and reduced lung function. In the present study, we investigated whether chronic bronchitis, asthma, or baseline methacholine airway responsiveness can explain the heterogeneity in lung function response to boilermaker work.

DESIGN

This study is part of an ongoing prospective cohort study of boilermakers. Exposure was assessed with a work history questionnaire. Spirometry was performed annually to assess lung function. A generalized estimating equation approach was used to account for the repeated-measures design.

SETTING

Boilermaker union members.

PARTICIPANTS

One hundred eighteen boilermakers participated in the study.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Self-reported history of chronic bronchitis and asthma were associated with a larger FEV1 reduction in response to workplace exposure at coal-fired and gas-fired industries. Although we found a high prevalence (39%) of airway hyperresponsiveness (provocative concentration of methacholine causing a 20% fall in FEV1 of < 8 mg/mL) among boilermakers, we did not find a consistent pattern of effect modification by airway responsiveness.

CONCLUSIONS

Although chronic bronchitis and asthma were associated with a greater loss in lung function in response to hours worked as a boilermaker, and therefore they acted as effect modifiers of the exposure-lung function relationship, airway hyperresponsiveness did not. However, the high prevalence of airway hyperresponsiveness found in the cohort may be a primary consequence of long-term workplace exposure among boilermakers.

Eosinophilia and musculoskeletal disease

Eosinophilia is occasionally a feature of rheumatic disease. The differential diagnosis of eosinophilia includes parasitic infection, systemic vasculitides, eosinophilic arthritis, and myopathies, together with the idiopathic hypereosinophilic syndrome and malignancy. Careful evaluation of the patient should enable an accurate diagnosis to be made. Parasitic infection is the commonest cause of eosinophilia worldwide and can cause systemic disease, as illustrated by the report of Sarcocystis myositis in a group of military personnel in Malaysia. A persistent arthropathy associated with eosinophilia, but not with parasitic infection, has been reported from the far East. Drugs may also cause eosinophilia, and there has recently been much discussion of the relation between Churg-Strauss syndrome and the leukotriene antagonist zafirlukast. The present view is that reduction of steroid dose allows unmasking of previously undiagnosed Churg-Strauss syndrome. The idiopathic hypereosinophilic syndrome may represent a lymphoproliferative process; evidence for this comes from the demonstration that many patients have a clonally expanded population of aberrant T cells.