Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE)

Altered regulation and expression of genes by BET family of proteins in COPD patients

BACKGROUND

BET proteins (BRD2, BRD3, BRDT and BRD4) belong to the family of bromodomain containing proteins, which form a class of transcriptional co-regulators. BET proteins bind to acetylated lysine residues in the histones of nucleosomal chromatin and function either as co-activators or co-repressors of gene expression. An imbalance between HAT and HDAC activities resulting in hyperacetylation of histones has been identified in COPD. We hypothesized that pan-BET inhibitor (JQ1) treatment of BET protein interactions with hyperacetylated sites in the chromatin will regulate excessive activation of pro-inflammatory genes in key inflammatory drivers of alveolar macrophages (AM) in COPD.

METHODS AND FINDINGS

Transcriptome analysis of AM from COPD patients indicated up-regulation of macrophage M1 type genes upon LPS stimulation. Pan-BET inhibitor JQ1 treatment attenuated expression of multiple genes, including pro-inflammatory cytokines and regulators of innate and adaptive immune cells. We demonstrated for the first time that JQ1 differentially modulated LPS-induced cytokine release from AM or peripheral blood mononuclear cells (PBMC) of COPD patients compared to PBMC of healthy controls. Using the BET regulated gene signature, we identified a subset of COPD patients, which we propose to benefit from BET inhibition.

CONCLUSIONS

This work demonstrates that the effects of pan-BET inhibition through JQ1 treatment of inflammatory cells differs between COPD patients and healthy controls, and the expression of BET protein regulated genes is altered in COPD. These findings provide evidence of histone hyperacetylation as a mechanism driving chronic inflammatory changes in COPD.

Genome-wide association analyses for lung function and chronic obstructive pulmonary disease identify new loci and potential druggable targets

Chronic obstructive pulmonary disease (COPD) is characterized by reduced lung function and is the third leading cause of death globally. Through genome-wide association discovery in 48,943 individuals, selected from extremes of the lung function distribution in UK Biobank, and follow-up in 95,375 individuals, we increased the yield of independent signals for lung function from 54 to 97. A genetic risk score was associated with COPD susceptibility (odds ratio per 1 s.d. of the risk score (∼6 alleles) (95% confidence interval) = 1.24 (1.20-1.27), P = 5.05 × 10-49), and we observed a 3.7-fold difference in COPD risk between individuals in the highest and lowest genetic risk score deciles in UK Biobank. The 97 signals show enrichment in genes for development, elastic fibers and epigenetic regulation pathways. We highlight targets for drugs and compounds in development for COPD and asthma (genes in the inositol phosphate metabolism pathway and CHRM3) and describe targets for potential drug repositioning from other clinical indications.

Ayurgenomics for stratified medicine: TRISUTRA consortium initiative across ethnically and geographically diverse Indian populations

BACKGROUND

Genetic differences in the target proteins, metabolizing enzymes and transporters that contribute to inter-individual differences in drug response are not integrated in contemporary drug development programs. Ayurveda, that has propelled many drug discovery programs albeit for the search of new chemical entities incorporates inter-individual variability "Prakriti" in development and administration of drug in an individualized manner. Prakriti of an individual largely determines responsiveness to external environment including drugs as well as susceptibility to diseases. Prakriti has also been shown to have molecular and genomic correlates. We highlight how integration of Prakriti concepts can augment the efficiency of drug discovery and development programs through a unique initiative of Ayurgenomics TRISUTRA consortium.

METHODS

Five aspects that have been carried out are (1) analysis of variability in FDA approved pharmacogenomics genes/SNPs in exomes of 72 healthy individuals including predominant Prakriti types and matched controls from a North Indian Indo-European cohort (2) establishment of a consortium network and development of five genetically homogeneous cohorts from diverse ethnic and geo-climatic background (3) identification of parameters and development of uniform standard protocols for objective assessment of Prakriti types (4) development of protocols for Prakriti evaluation and its application in more than 7500 individuals in the five cohorts (5) Development of data and sample repository and integrative omics pipelines for identification of genomic correlates.

RESULTS

Highlight of the study are (1) Exome sequencing revealed significant differences between Prakriti types in 28 SNPs of 11 FDA approved genes of pharmacogenomics relevance viz. CYP2C19, CYP2B6, ESR1, F2, PGR, HLA-B, HLA-DQA1, HLA-DRB1, LDLR, CFTR, CPS1. These variations are polymorphic in diverse Indian and world populations included in 1000 genomes project. (2) Based on the phenotypic attributes of Prakriti we identified anthropometry for anatomical features, biophysical parameters for skin types, HRV for autonomic function tests, spirometry for vital capacity and gustometry for taste thresholds as objective parameters. (3) Comparison of Prakriti phenotypes across different ethnic, age and gender groups led to identification of invariant features as well as some that require weighted considerations across the cohorts.

CONCLUSION

Considering the molecular and genomics differences underlying Prakriti and relevance in disease pharmacogenomics studies, this novel integrative platform would help in identification of differently susceptible and drug responsive population. Additionally, integrated analysis of phenomic and genomic variations would not only allow identification of clinical and genomic markers of Prakriti for application in personalized medicine but also its integration in drug discovery and development programs.

Ectopic fat accumulation in patients with COPD: an ECLIPSE substudy

BACKGROUND

Obesity is increasingly associated with COPD, but little is known about the prevalence of ectopic fat accumulation in COPD and whether this can possibly be associated with poor clinical outcomes and comorbidities. The Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) substudy tested the hypothesis that COPD is associated with increased ectopic fat accumulation and that this would be associated with COPD-related outcomes and comorbidities.

METHODS

Computed tomography (CT) images of the thorax obtained in ECLIPSE were used to quantify ectopic fat accumulation at L2-L3 (eg, cross-sectional area [CSA] of visceral adipose tissue [VAT] and muscle tissue [MT] attenuation, a reflection of muscle fat infiltration) and CSA of MT. A dose-response relationship between CSA of VAT, MT attenuation and CSA of MT and COPD-related outcomes (6-minute walking distance [6MWD], exacerbation rate, quality of life, and forced expiratory volume in 1 second [FEV₁] decline) was addressed with the Cochran-Armitage trend test. Regression models were used to investigate possible relationships between CT body composition indices and comorbidities.

RESULTS

From the entire ECLIPSE cohort, we identified 585 subjects with valid CT images at L2-L3 to assess body composition. CSA of VAT was increased (P<0.0001) and MT attenuation was reduced (indicating more muscle fat accumulation) in patients with COPD (P<0.002). Progressively increasing CSA of VAT was not associated with adverse clinical outcomes. The probability of exhibiting low 6MWD and accelerated FEV₁ decline increased with progressively decreasing MT attenuation and CSA of MT. In COPD, the probability of having diabetes (P=0.024) and gastroesophageal reflux (P=0.0048) at baseline increased in parallel with VAT accumulation, while the predicted MT attenuation increased the probability of cardiovascular comorbidities (P=0.042). Body composition parameters did not correlate with coronary artery scores or with survival.

CONCLUSION

Ectopic fat accumulation is increased in COPD, and this was associated with relevant clinical outcomes and comorbidities.

Biomarkers of extracellular matrix turnover are associated with emphysema and eosinophilic-bronchitis in COPD

Background

Chronic obstructive pulmonary disease (COPD) is characterized by airflow obstruction and loss of lung tissue mainly consisting of extracellular matrix (ECM). Three of the main ECM components are type I collagen, the main constituent in the interstitial matrix, type VI collagen, and elastin, the signature protein of the lungs. During pathological remodeling driven by inflammatory cells and proteases, fragments of these proteins are released into the bloodstream, where they may serve as biomarkers for disease phenotypes. The aim of this study was to investigate the lung ECM remodeling in healthy controls and COPD patients in the COPDGene study.

Methods

The COPDGene study recruited 10,300 COPD patients in 21 centers. A subset of 89 patients from one site (National Jewish Health), including 52 COPD patients, 12 never-smoker controls and 25 smokers without COPD controls, were studied for serum ECM biomarkers reflecting inflammation-driven type I and VI collagen breakdown (C1M and C6M, respectively), type VI collagen formation (Pro-C6), as well as elastin breakdown mediated by neutrophil elastase (EL-NE). Correlation of biomarkers with lung function, the SF-36 quality of life questionnaire, and other clinical characteristics was also performed.

Results

The circulating concentrations of biomarkers C6M, Pro-C6, and EL-NE were significantly elevated in COPD patients compared to never-smoking control patients (all p < 0.05). EL-NE was significantly elevated in emphysema patients compared to smoking controls (p < 0.05) and never-smoking controls (p < 0.005), by more than 250%. C1M was inversely associated with forced expiratory volume in 1 s (FEV₁) (r = −0.344, p = 0.001), as was EL-NE (r = −0.302, p = 0.004) and Pro-C6 (r = −0.259, p = 0.015). In the patients with COPD, Pro-C6 was correlated with percent predicted Forced Vital Capacity (FVC) (r = 0.281, p = 0.046) and quality of life using SF-36. C6M and Pro-C6, were positively correlated with blood eosinophil numbers in COPD patients (r = 0.382, p = 0.006 and r = 0.351, p = 0.012, respectively).

Conclusions

These data suggest that type VI collagen turnover and elastin degradation by neutrophil elastase are associated with COPD-induced inflammation (eosinophil-bronchitis) and emphysema. Serological assessment of type VI collagen and elastin turnover may assist in identification of phenotypes likely to be associated with progression and amenable to precision medicine for clinical trials.

The role of imperfect surrogate endpoint information in drug approval and reimbursement decisions

Approval of new drugs is increasingly reliant on "surrogate endpoints," which correlate with but imperfectly predict clinical benefits. Proponents argue surrogate endpoints allow for faster approval, but critics charge they provide inadequate evidence. We develop an economic framework that addresses the value of improvement in the predictive power, or "quality," of surrogate endpoints, and clarifies how quality can influence decisions by regulators, payers, and manufacturers. For example, the framework shows how lower-quality surrogates lead to greater misalignment of incentives between payers and regulators, resulting in more drugs that are approved for use but not covered by payers. Efficient price-negotiation in the marketplace can help align payer incentives for granting access based on surrogates. Higher-quality surrogates increase manufacturer profits and social surplus from early access to new drugs. Since the return on better quality is shared between manufacturers and payers, private incentives to invest in higher-quality surrogates are inefficiently low.

Quantitative Assessment of Erector Spinae Muscles in Patients with Chronic Obstructive Pulmonary Disease. Novel Chest Computed Tomography-derived Index for Prognosis

RATIONALE

Loss of skeletal muscle mass and physical inactivity are important manifestations of chronic obstructive pulmonary disease (COPD), and both are closely related to poor prognoses in patients with COPD. Antigravity muscles are involved in maintaining normal posture and are prone to atrophy with inactivity. The erector spinae muscles (ESM) are one of the antigravity muscle groups, and they can be assessed by chest computed tomography (CT).

OBJECTIVES

We hypothesized that the cross-sectional area of ESM (ESMCSA) visualized on chest CT images may serve as a predictor of mortality in patients with COPD.

METHODS

This study was part of the prospective observational study undertaken at Kyoto University Hospital. ESMCSA was measured on a single-slice axial CT image at the level of the 12th thoracic vertebra in patients with COPD. The cross-sectional area of the pectoralis muscles (PMCSA) was also measured. We evaluated the relationship between ESMCSA and clinical parameters, including mortality, in patients with COPD. Age- and height-matched smoking control subjects were also evaluated.

MEASUREMENTS AND MAIN RESULTS

In total, 130 male patients and 20 smoking control males were enrolled in this study. ESMCSA was significantly lower in patients with COPD than in the smoking control subjects and was significantly correlated with disease severity. There was a significant but only moderate correlation between ESMCSA and PMCSA. ESMCSA was significantly correlated with previously reported prognostic factors, such as body mass index, dyspnea (modified Medical Research Council dyspnea scale score), FEV1 percent predicted value, inspiratory capacity to total lung capacity ratio, and emphysema severity (percentage of the lung field occupied by low attenuation area). Compared with PMCSA, ESMCSA was more strongly associated with mortality in patients with COPD. Stepwise multivariate Cox proportional hazards analysis revealed that, among these known prognostic factors, ESMCSA was the strongest risk factor for mortality (hazard ratio, 0.85; 95% confidence interval, 0.79-0.92; P < 0.001) and mMRC dyspnea scale score was an additional factor (hazard ratio, 2.35; 95% confidence interval, 1.51-3.65; P < 0.001).

CONCLUSIONS

ESMCSA assessed by chest CT may be a valuable clinical parameter, as ESACSA correlates significantly with physiological parameters, symptoms, and disease prognosis.

The diagnosis of idiopathic pulmonary fibrosis: current and future approaches

With the recent development of two effective treatments for patients with idiopathic pulmonary fibrosis, an accurate diagnosis is crucial. The traditional approach to diagnosis emphasises the importance of thorough clinical and laboratory evaluations to exclude secondary causes of disease. High-resolution CT is a critical initial diagnostic test and acts as a tool to identify patients who should undergo surgical lung biopsy to secure a definitive histological diagnosis of usual interstitial pneumonia pattern. This diagnostic approach faces several challenges. Many patients with suspected idiopathic pulmonary fibrosis present with atypical high-resolution CT characteristics but are unfit for surgical lung biopsy, therefore preventing a confident diagnosis. The state of the art suggests an iterative, multidisciplinary process that incorporates available clinical, laboratory, imaging, and histological features. Recent research has explored genomic techniques to molecularly phenotype patients with interstitial lung disease. In the future, clinicians will probably use blood-specific or lung-specific molecular markers in combination with other clinical, physiological, and imaging features to enhance diagnostic efforts, refine prognostic recommendations, and influence the initial or subsequent treatment options. There is an urgent and increasing need for well designed, large, prospective studies measuring the effect of different diagnostic approaches. Ultimately, this will help to inform the development of guidelines and tailor clinical practice for the benefit of patients.

Findings on Thoracic Computed Tomography Scans and Respiratory Outcomes in Persons with and without Chronic Obstructive Pulmonary Disease: A Population-Based Cohort Study

BACKGROUND

Thoracic computed tomography (CT) scans are widely performed in clinical practice, often leading to detection of airway or parenchymal abnormalities in asymptomatic or minimally symptomatic individuals. However, clinical relevance of CT abnormalities is uncertain in the general population.

METHODS

We evaluated data from 1361 participants aged ≥40 years from a Canadian prospective cohort comprising 408 healthy never-smokers, 502 healthy ever-smokers, and 451 individuals with spirometric evidence of chronic obstructive pulmonary disease (COPD) who had thoracic CT scans. CT images of subjects were visually scored for respiratory bronchiolitis(RB), emphysema(E), bronchial-wall thickening(BWT), expiratory air-trapping(AT), and bronchiectasis(B). Multivariable logistic regression models were used to assess associations of CT features with respiratory symptoms, dyspnea, health status as determined by COPD assessment test, and risk of clinically significant exacerbations during 12 months follow-up.

RESULTS

About 11% of life-time never-smokers demonstrated emphysema on CT scans. Prevalence increased to 30% among smokers with normal lung function and 36%, 50%, and 57% among individuals with mild, moderate or severe/very severe COPD, respectively. Presence of emphysema on CT was associated with chronic cough (OR,2.11; 95%CI,1.4-3.18); chronic phlegm production (OR,1.87; 95% CI,1.27-2.76); wheeze (OR,1.61; 95% CI,1.05-2.48); dyspnoea (OR,2.90; 95% CI,1.41-5.98); CAT score≥10(OR,2.17; 95%CI,1.42-3.30) and risk of ≥2 exacerbations over 12 months (OR,2.17; 95% CI, 1.42-3.0).

CONCLUSIONS

Burden of thoracic CT abnormalities is high among Canadians ≥40 years of age, including never-smokers and smokers with normal lung function. Detection of emphysema on CT scans is associated with pulmonary symptoms and increased risk of exacerbations, independent of smoking or lung function.

SABRE: a method for assessing the stability of gene modules in complex tissues and subject populations

Background

Gene network inference (GNI) algorithms can be used to identify sets of coordinately expressed genes, termed network modules from whole transcriptome gene expression data. The identification of such modules has become a popular approach to systems biology, with important applications in translational research. Although diverse computational and statistical approaches have been devised to identify such modules, their performance behavior is still not fully understood, particularly in complex human tissues. Given human heterogeneity, one important question is how the outputs of these computational methods are sensitive to the input sample set, or stability. A related question is how this sensitivity depends on the size of the sample set. We describe here the SABRE (Similarity Across Bootstrap RE-sampling) procedure for assessing the stability of gene network modules using a re-sampling strategy, introduce a novel criterion for identifying stable modules, and demonstrate the utility of this approach in a clinically-relevant cohort, using two different gene network module discovery algorithms.

Results

The stability of modules increased as sample size increased and stable modules were more likely to be replicated in larger sets of samples. Random modules derived from permutated gene expression data were consistently unstable, as assessed by SABRE, and provide a useful baseline value for our proposed stability criterion. Gene module sets identified by different algorithms varied with respect to their stability, as assessed by SABRE. Finally, stable modules were more readily annotated in various curated gene set databases.

Conclusions

The SABRE procedure and proposed stability criterion may provide guidance when designing systems biology studies in complex human disease and tissues.

Electronic supplementary material

The online version of this article (doi:10.1186/s12859-016-1319-8) contains supplementary material, which is available to authorized users.

Hemizygous Deletion on Chromosome 3p26.1 Is Associated with Heavy Smoking among African American Subjects in the COPDGene Study

Many well-powered genome-wide association studies have identified genetic determinants of self-reported smoking behaviors and measures of nicotine dependence, but most have not considered the role of structural variants, such as copy number variation (CNVs), influencing these phenotypes. Here, we included 2,889 African American and 6,187 non-Hispanic White subjects from the COPDGene cohort (http://www.copdgene.org) to carefully investigate the role of polymorphic CNVs across the genome on various measures of smoking behavior. We identified a CNV component (a hemizygous deletion) on chromosome 3p26.1 associated with two quantitative phenotypes related to smoking behavior among African Americans. This polymorphic hemizygous deletion is significantly associated with pack-years and cigarettes smoked per day among African American subjects in the COPDGene study. We sought evidence of replication in African Americans from the population based Atherosclerosis Risk in Communities (ARIC) study. While we observed similar CNV counts, the extent of exposure to cigarette smoking among ARIC subjects was quite different and the smaller sample size of heavy smokers in ARIC severely limited statistical power, so we were unable to replicate our findings from the COPDGene cohort. But meta-analyses of COPDGene and ARIC study subjects strengthened our association signal. However, a few linkage studies have reported suggestive linkage to the 3p26.1 region, and a few genome-wide association studies (GWAS) have reported markers in the gene (GRM7) nearest to this 3p26.1 area of polymorphic deletions are associated with measures of nicotine dependence among subjects of European ancestry.

High levels of biomarkers of collagen remodeling are associated with increased mortality in COPD - results from the ECLIPSE study

Background

There is a need to identify individuals with COPD at risk for disease progression and mortality. Lung tissue remodeling is associated with the release of extracellular matrix (ECM) fragments into the peripheral circulation. We hypothesized that ECM remodeling was associated with mortality in COPD and measured neo-epitopes originating from ECM proteins associated with lung tissue remodeling.

Methods

Biomarkers of ECM remodeling were assessed in a subpopulation (n = 1000) of the Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE) cohort. Validated immunoassays measuring serological neo-epitopes produced by proteolytic cleavage associated with degradation of collagen type I, III, IV, and VI, elastin, and biglycan, and formation of collagen type VI as well as fibrinogen and C-reactive protein were used. Multivariate models were used to assess the prognostic value of these biomarkers.

Results

Thirty subjects (3.0 %) died during follow-up. Non-survivors were older, had reduced exercise capacity, increased dyspnea score, and included fewer current smokers. All collagen biomarkers were significantly elevated in non-survivors compared to survivors. Mortality risk was significantly increased for subjects with collagen remodeling biomarkers in the upper quartile, especially for the degradation fragment of collagen type IV C6M (hazard ratio 6.6 [95 % confidence interval 2.9-15.2], P < 0.0001) after adjusting for relevant confounders.

Conclusions

Serological biomarkers of collagen remodeling were strongly associated with mortality in subjects with COPD indicating that assessment of tissue turnover in the parenchyma and small airways may be useful in the prognosis of COPD.

Trial registration

NCT00292552, GSK Study No. SCO104960.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-016-0440-6) contains supplementary material, which is available to authorized users.

Choose your outcomes: From the mean to the personalized assessment of outcomes in COPD. An exploratory pragmatic survey

BACKGROUND

Patient's expectations and needs may influence adherence in chronic obstructive pulmonary disease (COPD). The objectives of this survey were to assess the specific outcomes that patients expected their COPD treatment to improve (patient's personal outcome [PPO]) and to evaluate how the ongoing therapy was able to reach this objective.

METHODS

We performed an exploratory pragmatic survey of COPD patients attending 2 university hospitals for scheduled follow-up visits. Patients had to indicate their PPO, the effect of ongoing treatment on the PPO, the symptom COPD of they expected treatment to improve and how this symptom is currently bothering them. Patients also underwent assessment of lung function and completed the COPD assessment test (CAT).

RESULTS

We analyzed data from 144 consecutive patients, (62.5% males; age range 54-94; mean age 73.88±8.33). A total of 23 different PPOs were scored, and 44.5% of patients reported an improvement ≥6 (mean 4.93±2.27 on a 0-10 points scale) due to ongoing treatment. The correlation between perceived improvement in PPO and CAT score was weak and negative (r=-0.13, p=0.11), whereas it was high and significant with FEV1 (r=.35, p=0.007). The clinical features patients most expected their ongoing treatment to improve were breathlessness (64.6% of patients), cough (13.9%), sputum production (11%) and episodes of exacerbation (8.3%), for which their scores were, respectively, 7.12±1.99, 6.8±2.24, 6.63±2.13, and 8.0±0.94.

CONCLUSION

Appropriate assessment of PPO could lead to better long-term management of COPD.

Importance of fractional exhaled nitric oxide in the differentiation of asthma-COPD overlap syndrome, asthma, and COPD

Background

Fractional exhaled nitric oxide (FeNO) is an easy, sensitive, reproducible, and noninvasive marker of eosinophilic airway inflammation. Accordingly, FeNO is extensively used to diagnose and manage asthma. Patients with COPD who share some of the features of asthma have a condition called asthma–COPD overlap syndrome (ACOS). The feasibility of using FeNO to differentiate ACOS patients from asthma and COPD patients remains unclear.

Methods

From February 2013 to May 2016, patients suspected with asthma and COPD through physician’s opinion were subjected to FeNO measurement, pulmonary function test (PFT), and bronchial hyperresponsiveness or bronchodilator test. Patients were divided into asthma alone group, COPD alone group, and ACOS group according to a clinical history, PFT values, and bronchial hyperresponsiveness or bronchodilator test. Receiver operating characteristic (ROC) curves were obtained to elucidate the clinical functions of FeNO in diagnosing ACOS. The optimal operating point was also determined.

Results

A total of 689 patients were enrolled in this study: 500 had asthma, 132 had COPD, and 57 had ACOS. The FeNO value in patients with ACOS was 27 (21.5) parts per billion (ppb; median [interquartile range]), which was significantly higher than that in the COPD group (18 [11] ppb). The area under the ROC curve was estimated to be 0.783 for FeNO. Results also revealed an optimal cutoff value of >22.5 ppb FeNO for differentiating ACOS from COPD patients (sensitivity 70%, specificity 75%).

Conclusion

FeNO measurement is an easy, noninvasive, and sensitive method for differentiating ACOS from COPD. This technique is a new perspective for the management of COPD patients.

Alterations in Serum Polyunsaturated Fatty Acids and Eicosanoids in Patients with Mild to Moderate Chronic Obstructive Pulmonary Disease (COPD)

Smoking is a major risk factor for several diseases including chronic obstructive pulmonary disease (COPD). To better understand the systemic effects of cigarette smoke exposure and mild to moderate COPD-and to support future biomarker development-we profiled the serum lipidomes of healthy smokers, smokers with mild to moderate COPD (GOLD stages 1 and 2), former smokers, and never-smokers (n = 40 per group) (ClinicalTrials.gov registration: NCT01780298). Serum lipidome profiling was conducted with untargeted and targeted mass spectrometry-based lipidomics. Guided by weighted lipid co-expression network analysis, we identified three main trends comparing smokers, especially those with COPD, with non-smokers: a general increase in glycero(phospho)lipids, including triglycerols; changes in fatty acid desaturation (decrease in ω-3 polyunsaturated fatty acids, and an increase in monounsaturated fatty acids); and an imbalance in eicosanoids (increase in 11,12- and 14,15-DHETs (dihydroxyeicosatrienoic acids), and a decrease in 9- and 13-HODEs (hydroxyoctadecadienoic acids)). The lipidome profiles supported classification of study subjects as smokers or non-smokers, but were not sufficient to distinguish between smokers with and without COPD. Overall, our study yielded further insights into the complex interplay between smoke exposure, lung disease, and systemic alterations in serum lipid profiles.

Effect of inhaled corticosteroids on blood eosinophil count in steroid-naïve patients with COPD

Introduction

Sputum and blood eosinophil counts have attracted attention as potential biomarkers in chronic obstructive pulmonary disease (COPD). One question regarding the use of blood eosinophils as a biomarker in COPD is whether their levels are affected by the use of inhaled corticosteroids (ICS), which are commonly prescribed for COPD.

Methods

We performed a retrospective analysis of peripheral blood leucocytes from a previously completed clinical trial that examined effects of ICS in steroid-naïve patients with COPD.

Results and conclusion

The data show that the ICS-containing treatment arms (containing fluticasone propionate) had a small effect on peripheral blood eosinophils in steroid-naïve patients with COPD.

Trial registration number

NCT00358358; Post-results.

The Effect of Different Case Definitions of Current Smoking on the Discovery of Smoking-Related Blood Gene Expression Signatures in Chronic Obstructive Pulmonary Disease

INTRODUCTION

Smoking is the number one modifiable environmental risk factor for chronic obstructive pulmonary disease (COPD). Clinical, epidemiological and increasingly "omics" studies assess or adjust for current smoking status using only self-report, which may be inaccurate. Objective measures such as exhaled carbon monoxide (eCO) may also be problematic owing to limitations in the measurements and the relatively short half life of the molecule. In this study, we determined the impact of different case definitions of current cigarette smoking on gene expression in peripheral blood of patients with COPD.

METHODS

Peripheral blood gene expression from 573 former- and current-smokers with COPD in the ECLIPSE study was used to find genes whose expression was associated with smoking status. Current smoking was defined using self-report, eCO concentrations, or both. Linear regression was used to determine the association of current smoking status with gene expression adjusting for age, sex and propensity score. Pathway enrichment analyses were performed on genes with P < .001.

RESULT

Using self-report or eCO, only two genes were differentially expressed between current and ex-smokers, with no enrichment in biological processes. When current smoking was defined using both eCO and self-report, four genes were differentially expressed (LRRN3, PID1, FUCA1, GPR15) with enrichment in 40 biological pathways related to metabolic processes, response to hypoxia and hormonal stimulus. Additionally, the combined definition provided better distributions of test statistics for differential gene expression.

CONCLUSION

A combined phenotype of eCO and self report allows for better discovery of genes and pathways related to current smoking.

IMPLICATIONS

Studies relying only on self report of smoking status to assess or adjust for the impact of smoking may not fully capture its effect and will lead to residual confounding of results.

Management of COPD: Is there a role for quantitative imaging?

While the recent development of quantitative imaging methods have led to their increased use in the diagnosis and management of many chronic diseases, medical imaging still plays a limited role in the management of chronic obstructive pulmonary disease (COPD). In this review we highlight three pulmonary imaging modalities: computed tomography (CT), magnetic resonance imaging (MRI) and optical coherence tomography (OCT) imaging and the COPD biomarkers that may be helpful for managing COPD patients. We discussed the current role imaging plays in COPD management as well as the potential role quantitative imaging will play by identifying imaging phenotypes to enable more effective COPD management and improved outcomes.

Determinants of exercise-induced oxygen desaturation including pulmonary emphysema in COPD: Results from the ECLIPSE study

Exercise-induced oxygen desaturation (EID) is related to mortality in patients with chronic obstructive pulmonary disease (COPD). We investigated: (1) the prevalence of EID; (2) the relative-weight of several physiological determinants of EID including pulmonary emphysema, and (3) the relationship of EID with certain patients' clinical characteristics. Data from 2050 COPD patients (age: 63.3 ± 7.1years; FEV₁: 48.7 ± 15.7%pred.) were analyzed. The occurrence of EID (SpO₂post ≤88%) at the six-minute walking test (6MWT) was investigated in association with emphysema quantified by computed-tomography (QCT), and several clinical characteristics. 435 patients (21%) exhibited EID. Subjects with EID had more QCT-emphysema, lower exercise capacity and worse health-status (BODE, ADO indexes) compared to non-EID. Determinant of EID were obesity (BMI≥30 kg/m²), impaired FEV₁ (≤44%pred.), moderate or worse emphysema, and low SpO₂ at rest (≤93%). Linear regression indicated that each 1-point increase on the ADO-score independently elevates odds ratio (≤1.5fold) for EID. About one in five COPD patients in the ECLIPSE cohort present EID. Advanced emphysema is associated with EID. In addition, obesity, severe airflow limitation, and low resting oxygen saturation increase the risk for EID. Patients with EID in GOLD stage II have higher odds to have moderate or worse emphysema compared those with EID in GOLD stage III-IV. Emphysematous patients with high ADO-score should be monitored for EID.

Measuring Airway Remodeling in Patients With Different COPD Staging Using Endobronchial Optical Coherence Tomography

BACKGROUND

Although FEV₁ remains the gold standard for staging COPD, the association between airway remodeling and airflow limitation remains unclear. Endobronchial optical coherence tomography (EB-OCT) was performed to assess the association between disorders of large and medium to small airways and COPD staging. We also evaluated small airway architecture in heavy smokers with normal FEV₁ (S_NL) and healthy never-smokers.

METHODS

We recruited 48 patients with COPD (stage I, n = 14; stage II, n = 15; stage, III-IV, n = 19), 21 S_NL, and 17 healthy never-smokers. A smoking history inquiry, as well as spirometry, chest CT, bronchoscopy, and EB-OCT were performed. Mean luminal diameter (D_mean), inner luminal area (Ai), and airway wall area (Aw) of third- to ninth-generation bronchi were measured using EB-OCT.

RESULTS

Patients with more advanced COPD demonstrated greater abnormality of airway architecture in both large and medium to small airways, followed by S_NL and never-smokers. Abnormality of airway architecture and EB-OCT parameters in S_NL were comparable to those in stage I COPD. FEV₁% predicted correlated with D_mean and Ai of seventh- to ninth-generation bronchi in COPD; however, neither D_mean nor Ai of third- to sixth-generation bronchi correlated with FEV₁% in stage I and stage II COPD and in S_NL.

CONCLUSIONS

FEV₁-based COPD staging partially correlates with small airway disorders in stage II-IV COPD. Small airway abnormalities detected by EB-OCT correlate with FEV₁-based staging in COPD and identify early pathologic changes in healthy heavy smokers.

A genome-wide analysis of the response to inhaled β2-agonists in chronic obstructive pulmonary disease

Short-acting β2-agonist bronchodilators are the most common medications used in treating chronic obstructive pulmonary disease (COPD). Genetic variants determining bronchodilator responsiveness (BDR) in COPD have not been identified. We performed a genome-wide association study (GWAS) of BDR in 5789 current or former smokers with COPD in one African-American and four white populations. BDR was defined as the quantitative spirometric response to inhaled β2-agonists. We combined results in a meta-analysis. In the meta-analysis, single-nucleotide polymorphisms (SNPs) in the genes KCNK1 (P=2.02 × 10(-7)) and KCNJ2 (P=1.79 × 10(-7)) were the top associations with BDR. Among African Americans, SNPs in CDH13 were significantly associated with BDR (P=5.1 × 10(-9)). A nominal association with CDH13 was identified in a gene-based analysis in all subjects. We identified suggestive association with BDR among COPD subjects for variants near two potassium channel genes (KCNK1 and KCNJ2). SNPs in CDH13 were significantly associated with BDR in African Americans.The Pharmacogenomics Journal advance online publication, 27 October 2015; doi:10.1038/tpj.2015.65.

Plasma Fibrinogen Qualification as a Drug Development Tool in Chronic Obstructive Pulmonary Disease. Perspective of the Chronic Obstructive Pulmonary Disease Biomarker Qualification Consortium

The COPD Foundation Biomarker Qualification Consortium (CBQC) is a unique public-private partnership established in 2010 between the COPD Foundation, the pharmaceutical industry, and academic chronic obstructive pulmonary disease (COPD) experts with advisors from the U.S. NHLBI and the Food and Drug Administration (FDA). This was a direct response to the 2009 publication of a guidance on qualification of drug development tools by the FDA. Although data were believed to be available from publicly funded and industry-funded studies that could support qualification of several tools, the necessary data resided in disparate databases. The initial intent of the CBQC was to integrate these data and submit a dossier for the qualification. This led to the FDA qualification of plasma fibrinogen as a prognostic or enrichment biomarker for all-cause mortality and COPD exacerbations in July 2015. It is the first biomarker drug development tool qualified for use in COPD under the FDA's drug development tool qualification program. This perspective summarizes the FDA's qualification process, the formation of the CBQC, and the effort that led to a successful outcome for plasma fibrinogen and discusses implications for future biomarker qualification efforts.

Development of an enhanced health-economic model and cost-effectiveness analysis of tiotropium + olodaterol Respimat® fixed-dose combination for chronic obstructive pulmonary disease patients in Italy

BACKGROUND

The objective of this study was to compare the cost-effectiveness of the fixed-dose combination (FDC) of tiotropium + olodaterol Respimat(®) FDC with tiotropium alone for patients with chronic obstructive pulmonary disease (COPD) in the Italian health care setting using a newly developed patient-level Markov model that reflects the current understanding of the disease.

METHODS

While previously published models have largely been based around a cohort approach using a Markov structure and GOLD stage stratification, an individual-level Markov approach was selected for the new model. Using patient-level data from the twin TOnado trials assessing Tiotropium + olodaterol Respimat(®) FDC versus tiotropium, outcomes were modelled based on the trough forced expiratory volume (tFEV1) of over 1000 patients in each treatment arm, tracked individually at trial visits through the 52-week trial period, and after the trial period it was assumed to decline at a constant rate based on disease stage. Exacerbation risk was estimated based on a random-effects logistic regression analysis of exacerbations in UPLIFT. Mortality by age and disease stage was estimated from an analysis of TIOSPIR trial data. Cost of bronchodilators and other medications, routine management, and costs of treatment for moderate and severe exacerbations for the Italian setting were included. A cost-effectiveness analysis was conducted over a 15-year time horizon from the perspective of the Italian National Health Service.

RESULTS

Aggregating total costs and quality-adjusted life years (QALYs) for each treatment cohort over 15 years and comparing tiotropium + olodaterol Respimat(®) FDC with tiotropium alone, resulted in mean incremental costs per patient of €1167 and an incremental cost-effectiveness ratio (ICER) of €7518 per additional QALY with tiotropium + olodaterol Respimat(®) FDC. The lung function outcomes observed for tiotropium + olodaterol Respimat(®) FDC in TOnado drove the results in terms of slightly higher mean life-years (12.24 versus 12.07) exacerbation-free months (11.36 versus 11.32) per patient and slightly fewer moderate and severe exacerbations per patient-year (0.411 versus 0.415; 0.21 versus 0.24) versus tiotropium. Probabilistic sensitivity analyses showed tiotropium + olodaterol Respimat(®) FDC to be the more cost-effective treatment in 95.2% and 98.4% of 500 simulations at thresholds of €20,000 and €30,000 per QALY respectively.

CONCLUSION

Tiotropium + olodaterol Respimat(®) FDC is a cost-effective bronchodilator in the maintenance treatment of COPD for the Italian health care system.

Sex Difference in Chronic Obstructive Lung Disease. Does it Matter? A Concise Review

Chronic obstructive lung disease (COPD) primarily affects men; however, its epidemiology has been changing because more women have become smokers. Recently, investigators found that although women and men were exposed to the same amount of smoke fume, women tended to have more severe disease and higher mortality rate. They also complain of more dyspnoea and may experience more severe exacerbations than men. This led to the question of whether sex has an impact on COPD course and whether women have a higher susceptibility to smoke fumes than men. That may be explained by multiple complex factors highlighting the relationship between sex, epidemiology, method of diagnostics and the clinical course of the disease. In this review, sex differences in epidemiology, clinical presentation, exacerbation, co-morbidities and treatment are covered.

Characteristics of elderly patients with COPD and newly diagnosed lung cancer, and factors associated with treatment decision

Objective

To investigate the clinical features, diagnosis, and treatment status of elderly patients with chronic obstructive pulmonary disease (COPD) complicated with lung cancer.

Patients and methods

This was a retrospective study of 206 patients aged >60 years with COPD and newly diagnosed lung cancer at the Tianjin Chest Hospital Respiratory Centre between September 2008 and September 2013. Lung function, radiology, and clinical data were retrieved.

Results

Among all patients, 57% (117/206) were hospitalized due to acute COPD aggravation, 47% (96/206) had COPD grade III or IV, 95% (195/206), showed diffusion dysfunction in pulmonary function examination, 90% (185/206) had a history of smoking, and 26% (54/206) were treated with inhaled corticosteroids for COPD treatment. Ninety-eight patients suffered from squamous carcinoma, 73 from adenocarcinoma, and 35 from small-cell carcinoma. Clinical staging was I in 36 patients, II in 47 patients, III in 78 patients, and IV in 45 patients. Initial treatments were surgery in 59 patients, chemotherapy in 30 patients, and no treatment in 117 patients. Multivariate analysis showed that age (P<0.001), COPD grades (P=0.01), clinical staging (P<0.001), and pulmonary diffusion function (P=0.007) were independent factors associated with patients with COPD being given treatments for lung cancer.

Conclusion

Younger patients with lower COPD grades, earlier lung cancer stage, and better pulmonary diffusion function are more likely to receive treatments.

Accuracy of forced oscillation technique to assess lung function in geriatric COPD population

Introduction

Performing lung function test in geriatric patients has never been an easy task. With well-established evidence indicating impaired small airway function and air trapping in patients with geriatric COPD, utilizing forced oscillation technique (FOT) as a supplementary tool may aid in the assessment of lung function in this population.

Aims

To study the use of FOT in the assessment of airflow limitation and air trapping in geriatric COPD patients.

Study design

A cross-sectional study in a public hospital in Hong Kong. ClinicalTrials.gov ID: NCT01553812.

Methods

Geriatric patients who had spirometry-diagnosed COPD were recruited, with both FOT and plethysmography performed. “Resistance” and “reactance” FOT parameters were compared to plethysmography for the assessment of air trapping and airflow limitation.

Results

In total, 158 COPD subjects with a mean age of 71.9±0.7 years and percentage of forced expiratory volume in 1 second of 53.4±1.7 L were recruited. FOT values had a good correlation (r=0.4–0.7) to spirometric data. In general, X values (reactance) were better than R values (resistance), showing a higher correlation with spirometric data in airflow limitation (r=0.07–0.49 vs 0.61–0.67), small airway (r=0.05–0.48 vs 0.56–0.65), and lung volume (r=0.12–0.29 vs 0.43–0.49). In addition, resonance frequency (Fres) and frequency dependence (FDep) could well identify the severe type (percentage of forced expiratory volume in 1 second <50%) of COPD with high sensitivity (0.76, 0.71) and specificity (0.72, 0.64) (area under the curve: 0.8 and 0.77, respectively). Moreover, X values could stratify different severities of air trapping, while R values could not.

Conclusion

FOT may act as a simple and accurate tool in the assessment of severity of airflow limitation, small and central airway function, and air trapping in patients with geriatric COPD who have difficulties performing conventional lung function test. Moreover, reactance parameters were better than resistance parameters in correlation with air trapping.

Meeting the challenge of COPD care delivery in the USA: a multiprovider perspective

The burden of chronic obstructive pulmonary disease (COPD) in the USA continues to grow. Although progress has been made in the the development of diagnostics, therapeutics, and care guidelines, whether patients' quality of life is improved will ultimately depend on the actual implementation of care and an individual patient's access to that care. In this Commission, we summarise expert opinion from key stakeholders-patients, caregivers, and medical professionals, as well as representatives from health systems, insurance companies, and industry-to understand barriers to care delivery and propose potential solutions. Health care in the USA is delivered through a patchwork of provider networks, with a wide variation in access to care depending on a patient's insurance, geographical location, and socioeconomic status. Furthermore, Medicare's complicated coverage and reimbursement structure pose unique challenges for patients with chronic respiratory disease who might need access to several types of services. Throughout this Commission, recurring themes include poor guideline implementation among health-care providers and poor patient access to key treatments such as affordable maintenance drugs and pulmonary rehabilitation. Although much attention has recently been focused on the reduction of hospital readmissions for COPD exacerbations, health systems in the USA struggle to meet these goals, and methods to reduce readmissions have not been proven. There are no easy solutions, but engaging patients and innovative thinkers in the development of solutions is crucial. Financial incentives might be important in raising engagement of providers and health systems. Lowering co-pays for maintenance drugs could result in improved adherence and, ultimately, decreased overall health-care spending. Given the substantial geographical diversity, health systems will need to find their own solutions to improve care coordination and integration, until better data for interventions that are universally effective become available.

Disease Modification in Emphysema Related to Alpha-1 Antitrypsin Deficiency

Alpha-1 antitrypsin deficiency (AATD) is associated with premature onset of emphysema resulting from low serum A₁-PI levels. The only available pharmacological treatment affecting the underlying cause of AATD is A₁-PI therapy. AATD-related emphysema is considered a good model to study disease-modifying effects of treatment as the causative process has been identified. Disease modification is a sustained improvement in disease state following therapeutic intervention that persists when therapy is discontinued. Appropriate trial design and the use of valid study endpoints are key to illustrating disease modification, particularly in clinical trials of rare diseases where it can be difficult to recruit sufficient numbers of patients. Delayed-start trials are advantageous ethically as all patients ultimately receive active treatment and imaging techniques have proven promising as valid study endpoints. Specifically, computed tomography (CT) measured lung density has been used to monitor emphysema and is considered a more sensitive outcome than pulmonary function tests to monitor disease progression. This review will discuss the importance of clinical endpoints and trial design to determine disease modification and will review the evidence for disease modification in AATD-related emphysema. Until recently, clinical studies have not shown a significant effect of A₁-PI therapy, possibly due to insufficient numbers of patients, short duration of clinical trials and lack of appropriate trial design. A recently completed randomised trial and open-label extension study followed a larger study population for a longer duration and incorporated a delayed-start design. The results demonstrated clinical efficacy of A₁-PI therapy and indicate that treatment is disease-modifying.

Ventilation Heterogeneity in Never-smokers and COPD:: Comparison of Pulmonary Functional Magnetic Resonance Imaging with the Poorly Communicating Fraction Derived From Plethysmography

RATIONALE AND OBJECTIVES

Pulmonary functional magnetic resonance imaging provides a way to quantify ventilation and its heterogeneity-a hallmark finding in chronic obstructive pulmonary disease (COPD). Unfortunately, the etiology and physiological meaning of ventilation defects and their relationship to pulmonary function and symptoms in COPD are not well understood. Another biomarker of ventilation heterogeneity is provided by the "poorly communicating fraction" (PCF), and is calculated as the ratio of total lung capacity to alveolar volume made using whole-body plethysmography. Our objective was to compare ventilation heterogeneity using hyperpolarized (3)He magnetic resonance imaging (MRI) and PCF measurements in elderly never-smokers and in ex-smokers with COPD.

MATERIALS AND METHODS

One hundred forty-six participants (71 ± 8 years, range = 48-87 years) provided written informed consent including 45 elderly never-smokers (71 ± 6 years, range = 61-84 years) and 101 ex-smokers with COPD (71 ± 8 years, range = 48-87 years). During a single 2-hour visit, spirometry, plethysmography, and hyperpolarized (3)He MRI were acquired. The MRI-derived ventilation defect percent (VDP) and plethysmography measurements were acquired and PCF values were calculated. Linear regression, Pearson correlations, and Bland-Altman analysis were used to evaluate the relationships for PCF and MRI VDP.

RESULTS

PCF (P < 0.001) and VDP (P < 0.001) were significantly increased with increasing COPD severity. There was a significant relationship for VDP and PCF (r = 0.68, P < 0.001) in all subjects and COPD subjects alone (r = 0.61, P < 0.001). Bland-Altman analysis showed that PCF and VDP were significantly different (mean bias = 9.7, upper limit = 32, lower limit = -13, P < 0.001), and in severe-grade COPD, PCF overestimates of VDP were significantly greater.

CONCLUSIONS

In elderly never-smokers and in ex-smokers with COPD, PCF and VDP are moderately correlated estimates of COPD ventilation heterogeneity that may be reflecting similar pathophysiology.

Circulating desmosine levels do not predict emphysema progression but are associated with cardiovascular risk and mortality in COPD

Elastin degradation is a key feature of emphysema and may have a role in the pathogenesis of atherosclerosis associated with chronic obstructive pulmonary disease (COPD). Circulating desmosine is a specific biomarker of elastin degradation. We investigated the association between plasma desmosine (pDES) and emphysema severity/progression, coronary artery calcium score (CACS) and mortality.pDES was measured in 1177 COPD patients and 110 healthy control subjects from two independent cohorts. Emphysema was assessed on chest computed tomography scans. Aortic arterial stiffness was measured as the aortic-femoral pulse wave velocity.pDES was elevated in patients with cardiovascular disease (p<0.005) and correlated with age (rho=0.39, p<0.0005), CACS (rho=0.19, p<0.0005) modified Medical Research Council dyspnoea score (rho=0.15, p<0.0005), 6-min walking distance (rho=-0.17, p<0.0005) and body mass index, airflow obstruction, dyspnoea, exercise capacity index (rho=0.10, p<0.01), but not with emphysema, emphysema progression or forced expiratory volume in 1 s decline. pDES predicted all-cause mortality independently of several confounding factors (p<0.005). In an independent cohort of 186 patients with COPD and 110 control subjects, pDES levels were higher in COPD patients with cardiovascular disease and correlated with arterial stiffness (p<0.05).In COPD, excess elastin degradation relates to cardiovascular comorbidities, atherosclerosis, arterial stiffness, systemic inflammation and mortality, but not to emphysema or emphysema progression. pDES is a good biomarker of cardiovascular risk and mortality in COPD.

Hyperpolarized 83Kr magnetic resonance imaging of alveolar degradation in a rat model of emphysema

Hyperpolarized ⁸³Kr surface quadrupolar relaxation (SQUARE) generates MRI contrast that was previously shown to correlate with surface-to-volume ratios in porous model surface systems. The underlying physics of SQUARE contrast is conceptually different from any other current MRI methodology as the method uses the nuclear electric properties of the spin I = 9/2 isotope ⁸³Kr. To explore the usage of this non-radioactive isotope for pulmonary pathophysiology, MRI SQUARE contrast was acquired in excised rat lungs obtained from an elastase-induced model of emphysema. A significant ⁸³Kr T₁ relaxation time increase in the SQUARE contrast was found in the elastase-treated lungs compared with the baseline data from control lungs. The SQUARE contrast suggests a reduction in pulmonary surface-to-volume ratio in the emphysema model that was validated by histology. The finding supports usage of ⁸³Kr SQUARE as a new biomarker for surface-to-volume ratio changes in emphysema.

Free Urinary Desmosine and Isodesmosine as COPD Biomarkers: The Relevance of Confounding Factors

Background: Desmosine (DES) and isodesmosine (IDES) have been widely discussed as potential biomarkers of COPD. However, their clinical utility and validity remains unproven. Aim: This study aims to progress DES/IDES evaluation as a chronic obstructive pulmonary disease (COPD) biomarker by investigating its urinary excretion in a large sample cohort with respect to a) which factors influence DES/IDES levels in a population of healthy control individuals and COPD individuals; b) whether DES/IDES levels enable the differentiation between COPD individuals and healthy control individuals; c) whether DES/IDES can be used to differentiate between fast and slow decliners in lung function. Methods: Urinary DES and IDES were quantified in 365 individuals (147 healthy control individuals and 218 COPD individuals) from the Evaluation of COPD Longitudinally to Indentify Predictive Surrogate Endpoints (ECLIPSE) study (NCT00292552) by employing a validated liquid chromatography tandem mass spectrometry (LC-MS/MS) method. Results: Age, gender, body mass index (BMI) and smoking have a significant (p<0.05) influence on DES/IDES urinary excretion and need to be corrected for when investigating DES/IDES as a disease biomarker. Urinary DES/IDES allowed a statistically relevant differentiation (p<0.05) between stable COPD individuals and healthy control individuals, however, assay sensitivity and specificity were low (62% and 73%, respectively). Furthermore, urinary DES/IDES does not allow the differentiation of fast and slow decliners in lung function. Conclusions: The present results suggest that while urinary DES/IDES excretion is related to COPD, it is not a sensitive or specific biomarker for COPD diagnosis or prognosis.

Surfactant protein D, a clinical biomarker for chronic obstructive pulmonary disease with excellent discriminant values

Biological markers can help to better identify a disease or refine its diagnosis. In the present study, the association between surfactant protein D (SP-D) and chronic obstructive pulmonary disease (COPD) was studied among subjects consulting for respiratory diseases or symptoms and was compared with C-reactive protein (CRP) and fibrinogen. A further aim of this study was to identify the optimal cut-off point of SP-D able to discriminate COPD patients. A case-control study including 90 COPD patients, 124 asthma patients and 180 controls was conducted. Standardized questionnaires were administered and lung function tests were performed. Biological markers were measured in blood samples according to standardized procedures. The association between SP-D and COPD was investigated using logistic regression models. Receiver-operating characteristic curves were used for threshold identification. SP-D levels above the median value were positively associated with COPD [adjusted odds ratio (OR)=3.86, 95% confidence interval (CI): 1.51-9.85, P=0.005). No associations with COPD or asthma were found for CRP or fibrinogen levels. Scores for COPD diagnosis in all COPD patients or ever-smoker COPD patients were identified (sensitivity, 76.4 and 77.8%; specificity, 89.3 and 88.5%, respectively). The results indicate that SP-D can differentiate COPD from other respiratory symptoms or diseases. Used with socio-demographic characteristics and respiratory symptoms, SP-D is able to discriminate COPD patients from controls, particularly among smokers.

Association Between Interstitial Lung Abnormalities and All-Cause Mortality

IMPORTANCE

Interstitial lung abnormalities have been associated with lower 6-minute walk distance, diffusion capacity for carbon monoxide, and total lung capacity. However, to our knowledge, an association with mortality has not been previously investigated.

OBJECTIVE

To investigate whether interstitial lung abnormalities are associated with increased mortality.

DESIGN, SETTING, AND POPULATION

Prospective cohort studies of 2633 participants from the FHS (Framingham Heart Study; computed tomographic [CT] scans obtained September 2008-March 2011), 5320 from the AGES-Reykjavik Study (Age Gene/Environment Susceptibility; recruited January 2002-February 2006), 2068 from the COPDGene Study (Chronic Obstructive Pulmonary Disease; recruited November 2007-April 2010), and 1670 from ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints; between December 2005-December 2006).

EXPOSURES

Interstitial lung abnormality status as determined by chest CT evaluation.

MAIN OUTCOMES AND MEASURES

All-cause mortality over an approximate 3- to 9-year median follow-up time. Cause-of-death information was also examined in the AGES-Reykjavik cohort.

RESULTS

Interstitial lung abnormalities were present in 177 (7%) of the 2633 participants from FHS, 378 (7%) of 5320 from AGES-Reykjavik, 156 (8%) of 2068 from COPDGene, and in 157 (9%) of 1670 from ECLIPSE. Over median follow-up times of approximately 3 to 9 years, there were more deaths (and a greater absolute rate of mortality) among participants with interstitial lung abnormalities when compared with those who did not have interstitial lung abnormalities in the following cohorts: 7% vs 1% in FHS (6% difference [95% CI, 2% to 10%]), 56% vs 33% in AGES-Reykjavik (23% difference [95% CI, 18% to 28%]), and 11% vs 5% in ECLIPSE (6% difference [95% CI, 1% to 11%]). After adjustment for covariates, interstitial lung abnormalities were associated with a higher risk of death in the FHS (hazard ratio [HR], 2.7 [95% CI, 1.1 to 6.5]; P = .03), AGES-Reykjavik (HR, 1.3 [95% CI, 1.2 to 1.4]; P < .001), COPDGene (HR, 1.8 [95% CI, 1.1 to 2.8]; P = .01), and ECLIPSE (HR, 1.4 [95% CI, 1.1 to 2.0]; P = .02) cohorts. In the AGES-Reykjavik cohort, the higher rate of mortality could be explained by a higher rate of death due to respiratory disease, specifically pulmonary fibrosis.

CONCLUSIONS AND RELEVANCE

In 4 separate research cohorts, interstitial lung abnormalities were associated with a greater risk of all-cause mortality. The clinical implications of this association require further investigation.

Biobehavioral Prognostic Factors in Chronic Obstructive Pulmonary Disease: Results From the INSPIRE-II Trial

OBJECTIVE

To examine the prognostic value of select biobehavioral factors in patients with chronic obstructive pulmonary disease (COPD) in a secondary analysis of participants from the INSPIRE-II trial.

METHODS

Three hundred twenty-six outpatients with COPD underwent assessments of pulmonary function, physical activity, body mass index, inflammation, pulmonary symptoms, depression, and pulmonary quality of life and were followed up for up to 5.4 years for subsequent clinical events. The prognostic value of each biobehavioral factor, considered individually and combined, also was examined in the context of existing Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2011 risk stratification.

RESULTS

Sixty-nine individuals experienced a hospitalization or died over a mean follow-up period of 2.4 (interquartile range = 1.6) years. GOLD classification was associated with an increased risk of clinical events (hazard ratio [HR] = 2.72 [95% confidence interval = 1.63-4.54], per stage); 6-minute walk (HR = 0.50 [0.34-0.73] per 500 ft), total steps (HR = 0.82 [0.71-0.94] per 1000 steps), high-sensitivity C-reactive protein (HR = 1.44 [1.01-2.06] per 4.5 mg/l), depression (HR = 1.12 [1.01-1.25] per 4 points), and pulmonary quality of life (HR = 1.73 [1.14-2.63] per 25 points) were each predictive over and above the GOLD assessment. However, only GOLD group and 6-minute walk were predictive of all-cause mortality and COPD hospitalization when all biobehavioral variables were included together in a multivariable model.

CONCLUSIONS

Biobehavioral factors provide added prognostic information over and above measures of COPD severity in predicting adverse events in patients with COPD.

Mitochondrial iron chelation ameliorates cigarette smoke-induced bronchitis and emphysema in mice

Chronic obstructive pulmonary disease (COPD) is linked to both cigarette smoking and genetic determinants. We have previously identified iron-responsive element-binding protein 2 (IRP2) as an important COPD susceptibility gene and have shown that IRP2 protein is increased in the lungs of individuals with COPD. Here we demonstrate that mice deficient in Irp2 were protected from cigarette smoke (CS)-induced experimental COPD. By integrating RNA immunoprecipitation followed by sequencing (RIP-seq), RNA sequencing (RNA-seq), and gene expression and functional enrichment clustering analysis, we identified Irp2 as a regulator of mitochondrial function in the lungs of mice. Irp2 increased mitochondrial iron loading and levels of cytochrome c oxidase (COX), which led to mitochondrial dysfunction and subsequent experimental COPD. Frataxin-deficient mice, which had higher mitochondrial iron loading, showed impaired airway mucociliary clearance (MCC) and higher pulmonary inflammation at baseline, whereas mice deficient in the synthesis of cytochrome c oxidase, which have reduced COX, were protected from CS-induced pulmonary inflammation and impairment of MCC. Mice treated with a mitochondrial iron chelator or mice fed a low-iron diet were protected from CS-induced COPD. Mitochondrial iron chelation also alleviated CS-induced impairment of MCC, CS-induced pulmonary inflammation and CS-associated lung injury in mice with established COPD, suggesting a critical functional role and potential therapeutic intervention for the mitochondrial-iron axis in COPD.

Cost-effectiveness of combination therapy umeclidinium/vilanterol versus tiotropium in symptomatic COPD Spanish patients

PURPOSE

Umeclidinium/vilanterol (UMEC/VI) is a novel fixed dose combination of a long-acting muscarinic receptor antagonist (LAMA) and a long-acting beta 2 receptor antagonist (LABA) agent. This analysis evaluated the incremental cost-effectiveness ratio (ICER) of UMEC/VI compared with tiotropium (TIO), from the Spanish National Health System (NHS) perspective.

METHODS

A previously published linked equations cohort model based on the epidemiological longitudinal study ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points) was used. Patients included were COPD patients with a post-bronchodilator forced expiratory volume in 1 second (FEV1) ≤70% and the presence of respiratory symptoms measured with the modified Medical Research Council dyspnea scale (modified Medical Research Council ≥2). Treatment effect, expressed as change in FEV1 from baseline, was estimated from a 24-week head-to-head phase III clinical trial comparing once-daily UMEC/VI with once-daily TIO and was assumed to last 52 weeks following treatment initiation (maximum duration of UMEC/VI clinical trials). Spanish utility values were derived from a published local observational study. Unitary health care costs (€2015) were obtained from local sources. A 3-year time horizon was selected, and 3% discount was applied to effects and costs. Results were expressed as cost/quality-adjusted life years (QALYs). Univariate and probabilistic sensitivity analysis (PSA) was performed.

RESULTS

UMEC/VI produced additional 0.03 QALY and €590 vs TIO, leading to an ICER of €21,475/QALY. According to PSA, the probability of UMEC/VI being cost-effective was 80.3% at a willingness-to-pay of €30,000/QALY.

CONCLUSION

UMEC/VI could be considered as a cost-effective treatment alternative compared with TIO in symptomatic COPD patients from the Spanish NHS perspective.

COPD subtypes identified by network-based clustering of blood gene expression

One of the most common smoking-related diseases, chronic obstructive pulmonary disease (COPD), results from a dysregulated, multi-tissue inflammatory response to cigarette smoke. We hypothesized that systemic inflammatory signals in genome-wide blood gene expression can identify clinically important COPD-related disease subtypes, and we leveraged pre-existing gene interaction networks to guide unsupervised clustering of blood microarray expression data. Using network-informed non-negative matrix factorization, we analyzed genome-wide blood gene expression from 229 former smokers in the ECLIPSE Study, and we identified novel, clinically relevant molecular subtypes of COPD. These network-informed clusters were more stable and more strongly associated with measures of lung structure and function than clusters derived from a network-naïve approach, and they were associated with subtype-specific enrichment for inflammatory and protein catabolic pathways. These clusters were successfully reproduced in an independent sample of 135 smokers from the COPDGene Study.

Quantitative computed tomography imaging in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease having small airway inflammation, emphysema, and pulmonary hypertension. It is now clear that spirometry alone cannot differentiate each component. Quantitative computed tomography (QCT) is increasingly used to quantify the amount of emphysema and small airway involvement in COPD. Inspiratory CT guides in assessing emphysema while expiratory CT identifies areas of air trapping which is a surrogate of small airway inflammation. By constructing a three-dimensional model of airways, we can also measure the airway wall thickness of segmental and subsegmental airways. The aim of this review is to present the current knowledge and methodologies in QCT of the lung that aid in identifying discrete COPD phenotypes.

Body mass index, airflow obstruction and dyspnea and body mass index, airflow obstruction, dyspnea scores, age and pack years-predictive properties of new multidimensional prognostic indices of chronic obstructive pulmonary disease in primary care

BACKGROUND

The assessment of the severity of chronic obstructive pulmonary disease (COPD) should involve a multidimensional approach that is now clearly shown to be better than using spirometric impairment alone. The aim of this study is to validate and compare novel tools without an exercise test and to extend prognostic value to patients with less severe impairment of Forced expiratory volume 1 s.

METHODS

A prospective, observational, primary care cohort study identified 458 eligible patients recruited from the primary care clinics in the northeast of England in 1999-2002. A new prognostic indicator - body mass index, airflow obstruction and dyspnea (BOD) together with the conventional prognostic indices age, dyspnea and airflow obstruction (ADO), global initiative for chronic obstructive lung disease (GOLD) and new GOLD matrix were studied. We also sought to improve prognostication of BOD by adding age (A) and smoking history as pack years (S) to validate BODS (BOD with smoking history) and BODAS (BOD with smoking history and age) as prognostic tools and the predictive power of each was analyzed.

RESULTS

The survival of the 458 patients was assessed after a median of 10 years when the mortality was found to be 33.6%. The novel indices BOD, BODS, and BODAS were significantly predictive for all-cause mortality in our cohort. Furthermore with ROC analysis the C statistics for BOD, BODS, and BODAS were 0.62, 0.66, and 0.72, respectively (P < 0.001 for each), whereas ADO and GOLD stages had a C statistic of 0.70 (P < 0.001) and 0.56 (P < 0.02), respectively. GOLD Matrix was not significant in this cohort.

CONCLUSION

BOD, BODS, and BODAS scores are validated predictors of all-cause mortality in a primary care cohort with COPD.