Chronic obstructive pulmonary disease biomarker(s) for disease activity needed--urgently

The association of vitamin K status with lung function and disease in a general population

Introduction

Matrix Gla protein (MGP) is an inhibitor of lung tissue calcification. The plasma level of dephosphorylated-uncarboxylated MGP (dp-ucMGP) is a biomarker of vitamin K status. The present study assessed whether lower vitamin K status (reflected by higher dp-ucMGP) was associated with lung function and lung disease/symptoms.

Methods

A general population sample of 4092 individuals, aged 24 to 77 years, underwent a health examination including questionnaires, spirometry and measurements of plasma dp-ucMGP. Associations of dp-ucMGP with lung function and self-reported disease/symptoms were estimated using regression models adjusted for age, sex and height. Associations were expressed as β-estimates or odds ratios (ORs) per doubling in dp-ucMGP.

Results

Lower vitamin K status (higher dp-ucMGP) was associated with lower forced expiratory volume in 1 s (FEV1) (98 mL; 95% CI: 54-141 mL) and lower forced vital capacity (FVC) (136 mL; 95% CI: 85-187 mL). Dp-ucMGP was not associated with the FEV1/FVC ratio (0.0 percentage points higher than the expected value; 95% CI: -1.0-1.0). Furthermore, lower vitamin K status was associated with COPD (OR 2.24, 95% CI: 1.53-3.27), wheezing (OR 1.81, 95% CI: 1.44-2.28) and asthma (OR 1.44, 95% CI: 1.12-1.83).

Conclusion

Lower vitamin K status was associated with lower ventilatory capacity (lower FEV1 and FVC), and with higher risk of self-reported asthma, COPD and wheezing. Vitamin K status was not associated with airflow obstruction (FEV1/FVC ratio).

Pulmonary Function Tests as a Biomarker in Diffuse Idiopathic Pulmonary Neuroendocrine Cell Hyperplasia Patients Treated With Somatostatin Analogues

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) describes an indolent, under-recognised and poorly understood pulmonary condition with fewer than 200 reported cases across the literature. Currently, cases are diagnosed following a biopsy of the primary lesion, with treatment options centring on symptomatic benefit as opposed to targeting the underlying aetiology. Classically, DIPNECH lesions have been described as slow growing and benign, but with growing awareness of the condition, reports of metastatic disease with significant symptomatic burden have been reported. However, effectively addressing the subset of DIPNECH patients with greater metastatic potential remains an unmet clinical need. Due to the similarities between DIPNECH and carcinoid patients, several centres have considered using somatostatin analogues to not only help symptomatically but also to initiate tumour regression. However, to date, there are limited biomarkers to help evaluate the benefit of such options. In this review, we consider the use of pulmonary function tests (PFTs) to help quantify the benefit of somatostatin analogues. Although much of the evidence stems from small single-centre studies, the use of PFTs within the treatment pathway for both localised and metastatic DIPNECH represents a meaningful improvement from subjective monitoring of disease.

Clusterin as a serum biomarker candidate contributes to the lung fibroblasts activation in chronic obstructive pulmonary disease

BACKGROUND

Fibrosis in the peripheral airways contributes to airflow limitation in patients with chronic obstructive pulmonary disease (COPD). However, the key proteins involved in its development are still poorly understood. Thus, we aimed to identify the differentially expressed proteins (DEPs) between smoker patients with and without COPD and elucidate the molecular mechanisms involved by investigating the effects of the identified biomarker candidate on lung fibroblasts.

METHODS

The potential DEPs were identified by isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic analysis. The messenger RNA and protein levels of clusterin (CLU) in COPD patients and 12% cigarette smoke extract (CSE)-treated human bronchial epithelial cells were determined at the indicated time points. Furthermore, an in vitro COPD model was established via the administration of 8% CSE to normal human lung fibroblasts (NHLFs) at indicated time points. The effects of CSE treatment and CLU silencing on proliferation and activation of lung fibroblasts were analyzed.

RESULTS

A total of 144 DEPs were identified between COPD patients and normal smokers. The iTRAQ-based proteomics and bioinformatics analyses identified CLU as a serum biomarker candidate. We also discovered that CLU levels were significantly increased ( P   <  0.0001) in Global Initiative for Obstructive Lung Disease II, III, and IV patients and correlated ( P   <  0.0001) with forced expiratory volume in 1 s ( R  = -0.7705), residual volume (RV) ( R  = 0.6281), RV/total lung capacity ( R  = 0.5454), and computerized tomography emphysema ( R  = 0.7878). Similarly, CLU levels were significantly increased in CSE-treated cells at indicated time points ( P  < 0.0001). The CSE treatment significantly inhibited the proliferation, promoted the inflammatory response, differentiation of NHLFs, and collagen matrix deposition, and induced the apoptosis of NHLFs; however, these effects were partially reversed by CLU silencing.

CONCLUSION

Our findings suggest that CLU may play significant roles during airway fibrosis in COPD by regulating lung fibroblast activation.

Treatment Trials in Young Patients with Chronic Obstructive Pulmonary Disease and Pre-Chronic Obstructive Pulmonary Disease Patients: Time to Move Forward

Chronic obstructive pulmonary disease (COPD) is the end result of a series of dynamic and cumulative gene-environment interactions over a lifetime. The evolving understanding of COPD biology provides novel opportunities for prevention, early diagnosis, and intervention. To advance these concepts, we propose therapeutic trials in two major groups of subjects: "young" individuals with COPD and those with pre-COPD. Given that lungs grow to about 20 years of age and begin to age at approximately 50 years, we consider "young" patients with COPD those patients in the age range of 20-50 years. Pre-COPD relates to individuals of any age who have respiratory symptoms with or without structural and/or functional abnormalities, in the absence of airflow limitation, and who may develop persistent airflow limitation over time. We exclude from the current discussion infants and adolescents because of their unique physiological context and COPD in older adults given their representation in prior randomized controlled trials (RCTs). We highlight the need of RCTs focused on COPD in young patients or pre-COPD to reduce disease progression, providing innovative approaches to identifying and engaging potential study subjects. We detail approaches to RCT design, including potential outcomes such as lung function, patient-reported outcomes, exacerbations, lung imaging, mortality, and composite endpoints. We critically review study design components such as statistical powering and analysis, duration of study treatment, and formats to trial structure, including platform, basket, and umbrella trials. We provide a call to action for treatment RCTs in 1) young adults with COPD and 2) those with pre-COPD at any age.

InforMing the PAthway of COPD Treatment (IMPACT) trial: fibrinogen levels predict risk of moderate or severe exacerbations

BACKGROUND

Fibrinogen is the first qualified prognostic/predictive biomarker for exacerbations in patients with chronic obstructive pulmonary disease (COPD). The IMPACT trial investigated fluticasone furoate/umeclidinium/vilanterol (FF/UMEC/VI) triple therapy versus FF/VI and UMEC/VI in patients with symptomatic COPD at risk of exacerbations. This analysis used IMPACT trial data to examine the relationship between fibrinogen levels and exacerbation outcomes in patients with COPD.

METHODS

8094 patients with a fibrinogen assessment at Week 16 were included, baseline fibrinogen data were not measured. Post hoc analyses were performed by fibrinogen quartiles and by 3.5 g/L threshold. Endpoints included on-treatment exacerbations and adverse events of special interest (AESIs).

RESULTS

Rates of moderate, moderate/severe, and severe exacerbations were higher in the highest versus lowest fibrinogen quartile (0.75, 0.92 and 0.15 vs 0.67, 0.79 and 0.10, respectively). The rate ratios (95% confidence interval [CI]) for exacerbations in patients with fibrinogen levels ≥ 3.5 g/L versus those with fibrinogen levels < 3.5 g/L were 1.03 (0.95, 1.11) for moderate exacerbations, 1.08 (1.00, 1.15) for moderate/severe exacerbations, and 1.30 (1.10, 1.54) for severe exacerbations. There was an increased risk of moderate/severe exacerbation (hazard ratio [95% CI]: highest vs lowest quartile 1.16 [1.04, 1.228]; ≥ 3.5 g/L vs < 3.5 g/L: 1.09 [1.00, 1.16]) and severe exacerbation (1.35 [1.09, 1.69]; 1.27 [1.08, 1.47], respectively) with increasing fibrinogen level. Cardiovascular AESIs were highest in patients in the highest fibrinogen quartile.

CONCLUSIONS

Rate and risk of exacerbations was higher in patients with higher fibrinogen levels. This supports the validity of fibrinogen as a predictive biomarker for COPD exacerbations, and highlights the potential use of fibrinogen as an enrichment strategy in trials examining exacerbation outcomes.

TRIAL REGISTRATION

NCT02164513.

Markers of disease activity in COPD: an 8-year mortality study in the ECLIPSE cohort

Rationale

There are no validated measures of disease activity in COPD. Since “active” disease is expected to have worse outcomes (e.g. mortality), we explored potential markers of disease activity in patients enrolled in the ECLIPSE cohort in relation to 8-year all-cause mortality.

Methods

We investigated 1) how changes in relevant clinical variables over time (1 or 3 years) relate to 8-year mortality; 2) whether these variables inter-relate; and 3) if any clinical, imaging and/or biological marker measured cross-sectionally at baseline relates to any activity component.

Results

Results showed that 1) after 1 year, hospitalisation for COPD, exacerbation frequency, worsening of body mass index, airflow obstruction, dyspnoea and exercise (BODE) index or health status (St George's Respiratory Questionnaire (SGRQ)) and persistence of systemic inflammation were significantly associated with 8-year mortality; 2) at 3 years, the same markers, plus forced expiratory volume in 1 s (FEV₁) decline and to a lesser degree computed tomography (CT) emphysema, showed association, thus qualifying as markers of disease activity; 3) changes in FEV₁, inflammatory cytokines and CT emphysema were not inter-related, while the multidimensional indices (BODE and SGRQ) showed modest correlations; and 4) changes in these markers could not be predicted by any baseline cross-sectional measure.

Conclusions

In COPD, 1- and 3-year changes in exacerbation frequency, systemic inflammation, BODE and SGRQ scores and FEV₁ decline are independent markers of disease activity associated with 8-year all-cause mortality. These disease activity markers are generally independent and not predictable from baseline measurements.

In patients with COPD, 1- and 3-year changes in exacerbation frequency, systemic inflammation, BODE and SGRQ scores, and FEV₁ decline, are independent markers of disease activity associated with 8-year all-cause mortalityhttps://bit.ly/2CyifcN

The Effectiveness of 3 Combined Therapeutic Regimens in Egyptian Patients with Moderate-to-Severe Chronic Obstructive Pulmonary Disease: A Randomized Double-Blind Prospective Pilot Study

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LABA+ICS, LAMA+ICS and LABA+LAMA improved FEV1 % predicted

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The three therapeutic combinations showed statistically similar safety profiles and efficacy

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The results of this pilot study suggest that TNF-α, fibrinogen and IL-6 can be used to monitor disease progression or guide therapeutic decisions.

Background

There are differences of opinion about both the most effective combined therapeutic strategy and the clinical benefit of inhaled corticosteroids in nonasthmatic patients with chronic obstructive pulmonary disease. Furthermore, many inflammatory cytokines are reportedly correlated with severity of the disease.

Objectives

To compare the effectiveness of long acting β-agonist + long-acting muscarinic antagonist (LABA + LAMA) versus LABA + inhaled corticosteroid and LAMA + inhaled corticosteroid in nonasthmatic patients with moderate-to-severe chronic obstructive pulmonary disease. To assess the changes that occurred in plasma concentrations of tumor necrosis factor α, fibrinogen, and interleukin 6, and correlate these with disease activity.

Methods

In this pilot study, 45 nonasthmatic patients with moderate to severe chronic obstructive pulmonary disease were randomized into 3 groups with 15 patients in each group. Group I (LABA + inhaled corticosteroid) received formoterol/budesonide, group II (LAMA + inhaled corticosteroid) received tiotropium/budesonide and group III (LABA + LAMA) received formoterol/tiotropium for 12 weeks. Patients were assessed initially and then at 4 and 12 weeks by measuring the changes that occurred in forced expiratory volume in 1 second as a percent of predicted and in the modified Medical Research Council dyspnea scale. Plasma concentrations of tumor necrosis factor α, fibrinogen, and interleukin 6 were simultaneously measured.

Results

The 3 study groups were statistically similar with respect to their demographic data and disease characteristics. All therapeutic options produced an improvement in forced expiratory volume in 1 second as a percent of predicted and in the modified Medical Research Council dyspnea scale as well as a reduction in plasma concentrations of the inflammatory markers. The effects produced by the three therapeutic combinations on forced expiratory volume in 1 second as a percent of predicted, plasma tumor necrosis factor α, interleukin 6, and fibrinogen concentrations were statistically similar after 4 and 12 weeks (4 weeks after treatment: P = 0.358, P = 0.284, P = 0.155, and P = 0.155, respectively, and 12 weeks after treatment: P = 0.710, P = 0.773, P = 0.240, and P = 0.076, respectively).

Conclusions

In nonasthmatic patients with moderate to severe chronic obstructive pulmonary disease, the 3 therapeutic combinations showed similar effectiveness. The results of this pilot study also suggest that inflammatory markers can be used to track disease activity. Clinicaltrials.gov identifier: NCT04520230. (Curr Ther Res Clin Exp. 2021; 82:XXX–XXX)

Peripheral blood CD4+ T cell populations by CD25 and Foxp3 expression as a potential biomarker: reflecting inflammatory activity in chronic obstructive pulmonary disease

Background

The temporally dynamic changes of CD25 and Foxp3 expression in CD4+ T cells are initiated by T cell receptor (TCR) signals strength or frequency. There is a deficiency of peripheral markers for assessing COPD activity, and the current study was conducted to explore whether peripheral CD4+ T cell populations based on CD25 and Foxp3 expression could serve as an indicator for COPD inflammatory activity.

Methods

The distribution and phenotypic characteristics of CD4+CD25±Foxp3± T cells from peripheral blood in different populations were determined by flow cytometry. The model for the differentiation of CD4+ T cells populations by CD25 and Foxp3 expression was explored in vitro.

Results

The frequencies of peripheral CD4+CD25+Foxp3- T cells and CD4+CD25+Foxp3+ T cells were increased in AECOPD patients, whereas the frequency of CD4+CD25-Foxp3+ T cells was increased in SCOPD patients without receiving systemic treatment. Phenotypic analysis revealed that CD4+CD25+Foxp3- T cells, CD4+CD25+Foxp3+ T cells and CD4+CD25-Foxp3+ T cells had received antigenic stimulation and resembled central memory or effector memory T cells. The differentiation of CD4+ T cells populations by CD25 and Foxp3 expression was dictated by TCR signals. The paired study indicated that the frequencies of CD4+CD25+Foxp3- T cells, CD4+CD25+Foxp3+ T cells and CD4+CD25- Foxp3+ T cells were decreased while the frequency of CD4+CD25-Foxp3- T cells were increased in the same patients from AECOPD to convalescence.

Conclusions

Collectively, we propose that the dynamic changes of CD4+ T cell populations by CD25 and Foxp3 expression could function as potential biomarkers for reflecting inflammatory activity in COPD.

Type IV collagen turnover is predictive of mortality in COPD: a comparison to fibrinogen in a prospective analysis of the ECLIPSE cohort

BACKGROUND

Identifying subjects with chronic obstructive pulmonary disease (COPD) at high risk of exacerbation and mortality is key to aid individual management of COPD. The only FDA approved blood-based drug development biomarker for patients at high risk of mortality, is plasma fibrinogen. In this study, we benchmarked two biomarkers of basement membrane remodeling, a characteristic of COPD, against plasma fibrinogen alone and as a combination. The biomarkers of basement membrane remodeling are two neoepitopes from of the alpha 3 chain of type IV collagen (COL4A3).

MATERIALS AND METHODS

COL4A3 degradation was assessed by the biomarkers C4Ma3 and tumstatin (TUM) in year 1 plasma samples in 984 COPD subjects, 95 non-smoking controls and 95 smoking controls from the Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE) cohort. They were measured by competitive ELISA using monoclonal antibodies recognizing two specific MMP-generated cleavage site within COL4A3. The level of fibrinogen was previously assessed in year 1 plasma.

RESULTS

In COPD subjects, plasma C4Ma3 levels were significantly correlated with plasma fibrinogen levels (0.389 (P < 0.0001)). Cox proportional-hazards regression adjusted for relevant confounders showed that high levels of plasma C4Ma3, but not TUM, were related to a higher risk of mortality (hazard ratio 5.12 (95% CI 2.28-11.50), P < 0.0001). High levels of plasma fibrinogen were not associated with all-cause mortality in this subpopulation, contradictory to published results. Whereas plasma C4Ma3 multiplied by fibrinogen showed to be related to a higher risk of mortality (hazard ratio 5.74 (95% CI 2.65-12.41), P < 0.0001). Plasma C4Ma3 levels were related to the number of hospitalizations due to COPD exacerbations in the year before study start (P = 0.0375). Fibrinogen levels were related to hospitalized exacerbations prior to study start (P = 0.0058) and were also related to future exacerbations (P < 0.0001).

CONCLUSION

We compared herein fibrinogen, C4Ma3 and TUM as biomarkers for COPD prognosis. Fibrinogen was related to future exacerbation, whereas C4Ma3 and the combination of C4Ma3 with fibrinogen were superior to fibrinogen alone in predicting mortality. This pilot study suggests that the assessment of plasma C4Ma3 could be important for identifying COPD patients with a poor prognosis.

TRIAL REGISTRATION

NCT00292552 , GSK Study No. SCO104960.

Specific elastin degradation products are associated with poor outcome in the ECLIPSE COPD cohort

Chronic obstructive pulmonary disease (COPD) is characterized by a slow heterogeneous progression. Therefore, improved biomarkers that can accurately identify patients with the highest likelihood of progression and therefore the ability to benefit from a given treatment, are needed. Elastin is an essential structural protein of the lungs. In this study, we investigated whether elastin degradation products generated by the enzymes proteinase 3, cathepsin G, neutrophil elastase, MMP7 or MMP9/12 were prognostic biomarkers for COPD-related outcomes. The elastin degradome was assessed in a subpopulation (n = 1307) of the Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE) cohort with 3 years of clinical follow-up. Elastin degraded by proteinase 3 could distinguish between COPD participants and non-smoking controls (p = 0.0006). A total of 30 participants (3%) died over the 3 years of observation. After adjusting for confounders, plasma levels of elastin degraded by proteinase 3 and cathepsin G were independently associated with mortality outcome with a hazard ratio per 1 SD of 1.49 (95%CI 1.24-1.80, p < 0.0001) and 1.31 (95%CI 1.10-1.57, p = 0.0029), respectively. Assessing the elastin degradome demonstrated that specific elastin degradation fragments have potential utility as biomarkers identifying subtypes of COPD patients at risk of poor prognosis and supports further exploration in confirmatory studies.

Annual change in FEV1 in elderly 10-year survivors with established chronic obstructive pulmonary disease

Long-term decline in lung function is generally considered to be progressive in individuals with established chronic obstructive pulmonary disease (COPD), despite the presence of intersubject variation. We hypothesized that the annualized rate of decline in forced expiratory volume in 1 second (FEV₁) would not be constant among different time periods in the natural history of established COPD. We compared the annual change rates in FEV₁ during the first 5 years and the last 5 years, estimated separately using a linear mixed-effects model in 10-year survivors (n = 110). The subjects were classified into three FEV₁ decline groups, based on the 25th and 75th percentile values in each time period. The rates of FEV₁ changes, calculated from the first 5 years and the last 5 years, did not correlate with each other among 10-year survivors; the subjects of each FEV₁ decline group during the first 5 years did not consistently remain in the same FEV₁ decline group during the last 5 years. Smoking status and exacerbation frequency were not associated with decline in FEV₁. In conclusion, the disease activity, which is often expressed as annualized change in FEV₁, might be changeable either way over years in patients with established COPD.

Soluble urokinase-type plasminogen activator receptor as a measure of treatment response in acute exacerbation of COPD

Objective:

To evaluate the value of soluble urokinase-type plasminogen activator receptor (suPAR) in the diagnosis of acute exacerbation of COPD (AECOPD) and in monitoring treatment response, analyzing the relationship between suPAR and fibrinogen in AECOPD. AECOPD leads to increased airway inflammation, contributing to an exaggerated release of inflammatory mediators.

Methods:

We recruited 45 patients with AECOPD and 20 healthy control subjects. Medical histories were taken, and all subjects underwent clinical examination, chest X-ray, pulmonary function tests, and blood gas analysis. On day 1 (treatment initiation for the AECOPD patients) and day 14 (end of treatment), blood samples were collected for the determination of serum suPAR and plasma fibrinogen.

Results:

Serum levels of suPAR were significantly higher in the AECOPD group than in the control group. In the AECOPD patients, there was a significant post-treatment decrease in the mean serum suPAR level. The sensitivity, specificity, and accuracy of suPAR were 95.6%, 80.0%, and 93.0%, respectively. The Global Initiative for Chronic Obstructive Lung Disease stage (i.e., COPD severity) correlated positively and significantly with serum levels of suPAR and plasma levels of fibrinogen.

Conclusions:

Monitoring the serum suPAR level can be helpful in the evaluation of the COPD treatment response and might be a valuable biomarker for determining the prognosis of AECOPD. Because serum suPAR correlated with plasma fibrinogen, both markers could be predictive of AECOPD.

Lung tissue destruction by proteinase 3 and cathepsin G mediated elastin degradation is elevated in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by high levels of protease activity leading to degradation of elastin followed by loss of elasticity of the lung and the development of emphysema. Elastin is an essential structural component of the lung parenchyma to support the expansion and recoil of the alveoli during breathing. The lung extracellular matrix is vulnerable to pathological structural changes upon upregulation of serine proteases, including cathepsin G (CG) and proteinase 3 (PR3). In this study, we explored the diagnostic features of elastin neo-epitopes generated by CG and PR3. Two novel competitive enzyme-linked immunosorbent assays (ELISA) measuring CG and PR3 generated elastin fragments (EL-CG and ELP-3 respectively) were developed for assessment in serum. Both assays were technically robust and biologically validated in serum from patients with COPD. Serological levels of both elastin fragments were significantly elevated in patients with COPD compared to healthy controls. These data suggest that EL-CG and ELP-3 may serve as plausible biologic markers of destructive changes in COPD.

Biomarkers of collagen turnover are related to annual change in FEV1 in patients with chronic obstructive pulmonary disease within the ECLIPSE study

Background

Change in forced expiratory volume in one second (FEV₁) is important for defining severity of chronic obstructive pulmonary disease (COPD). Serological neoepitope markers of collagen turnover may predict rate of change in FEV₁.

Methods

One thousand COPD subjects from the observational, multicentre, three-year ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints) study (NCT00292552, trial registration in February 2006) were included. Matrix metalloproteinase (MMP)-generated fragments of collagen type I, and type VI (C1M and C6M) were assessed in month six serum samples. A random-coefficient model with both a random intercept and a random slope was used to test the ability of the markers to predict post-dose bronchodilator FEV₁ (PD-FEV₁) change over two years adjusting for sex, age, BMI, smoking, bronchodilator reversibility, prior exacerbations, emphysema and chronic bronchitis status at baseline.

Results

Annual change of PD-FEV₁ was estimated from a linear model for the two-year study period. Serum C1M and C6M were independent predictors of lung function change (p = 0.007/0.005). Smoking, bronchodilator reversibility, plasma hsCRP and emphysema were also significant predictors. The effect estimate between annual change in PD-FEV₁ per one standard deviation (1SD) increase of C1M and C6M was +10.4 mL/yr. and +8.6 mL/yr. C1M, and C6M, had a significant association with baseline FEV₁.

Conclusion

We demonstrated that markers of tissue turnover were significantly associated with lung function change. These markers may function as prognostic biomarkers and possibly as efficacy biomarkers in clinical trials focusing on lung function change in COPD.

Trial registration

NCT00292552, Retrospectively registered, trial registration in February 2006.

Electronic supplementary material

The online version of this article (10.1186/s12890-017-0505-4) contains supplementary material, which is available to authorized users.

Different impacts of respiratory symptoms and comorbidities on COPD-specific health-related quality of life by COPD severity

Background

Patients with chronic obstructive pulmonary disease (COPD) often have poor health-related quality of life (HRQoL) that is disproportionate to their degree of airflow limitation. This study evaluated the association between St George's Respiratory Questionnaire for COPD (SGRQ-C) score and forced expiratory volume in one second and investigated the factors responsible for high SGRQ-C score according to severity of airflow limitation.

Methods

Data from 1,264 COPD patients were obtained from the Korean COPD Subgroup Study (KOCOSS) cohort. Patients were categorized into two groups according to severity of airflow limitation: mild-to-moderate and severe-to-very severe COPD groups. We evaluated the clinical factors associated with high SGRQ-C score (≥25) in each COPD patient group.

Results

Of the 1,264 COPD patients, 902 (71.4%) had mild-to-moderate airflow limitation and 362 (28.6%) had severe-to-very severe airflow limitation. Of the mild-to-moderate COPD patients, 59.2% (534/902) had high SGRQ-C score, while 80.4% (291/362) of the severe-to-very severe COPD patients had high SGRQ-C score. The association between SGRQ-C score and post-bronchodilator forced expiratory volume in one second (% predicted) was very weak in the mild-to-moderate COPD patients (r=-0.103, p=0.002) and weak in the severe-to-very severe COPD patients (r=-0.219, p<0.001). Multiple logistic regression analysis revealed that age, being an ex- or current smoker, lower level of education, cough, dyspnea, and number of comorbidities with congestive heart failure, hyperlipidemia, and depression were significantly associated with high SGRQ-C score in mild-to-moderate COPD patients. In comparison, being an ex-smoker and having respiratory symptoms including sputum and dyspnea were significant factors associated with high SGRQ-C score in severe-to-very severe COPD patients.

Conclusions

In addition to the respiratory symptoms of dyspnea and cough, high SGRQ-C score was associated with extra-pulmonary comorbidities in mild-to-moderate COPD patients. However, only respiratory symptoms such as sputum and dyspnea were significantly associated with high SGRQ-C score in severe-to-very severe COPD patients. This indicates the need for an improved management strategy for relieving respiratory symptoms in COPD patients with poor HRQoL. In addition, attention should be paid to extra-pulmonary comorbidities, especially in mild-to-moderate COPD patients with poor HRQoL.

The EASI model: A first integrative computational approximation to the natural history of COPD

The natural history of chronic obstructive pulmonary disease (COPD) is still not well understood. Traditionally believed to be a self-inflicted disease by smoking, now we know that not all smokers develop COPD, that other inhaled pollutants different from cigarette smoke can also cause it, and that abnormal lung development can also lead to COPD in adulthood. Likewise, the inflammatory response that characterizes COPD varies significantly between patients, and not all of them perceive symptoms (mostly breathlessness) similarly. To investigate the variability and determinants of different “individual natural histories” of COPD, we developed a theoretical, multi-stage, computational model of COPD (EASI) that integrates dynamically and represents graphically the relationships between exposure (E) to inhaled particles and gases (smoking), the biological activity (inflammatory response) of the disease (A), the severity (S) of airflow limitation (FEV₁) and the impact (I) of the disease (breathlessness) in different clinical scenarios. EASI shows that the relationships between E, A, S and I vary markedly within individuals (through life) and between individuals (at the same age). It also helps to delineate some potentially relevant, but often overlooked concepts, such as disease progression, susceptibility to COPD and issues related to symptom perception.

In conclusion, EASI is an initial conceptual model to interpret the longitudinal and cross-sectional relationships between E, A, S and I in different clinical scenarios. Currently, it does not have any direct clinical application, thus it requires experimental validation and further mathematical development. However, it has the potential to open novel research and teaching alternatives.

Integrative Genomics of Emphysema-Associated Genes Reveals Potential Disease Biomarkers

Chronic obstructive pulmonary disease is the third leading cause of death worldwide. Gene expression profiling across multiple regions of the same lung identified genes significantly related to emphysema. We sought to determine whether the lung and epithelial expression of 127 emphysema-related genes was also related to lung function in independent cohorts, and whether any of these genes could be used as biomarkers in the peripheral blood of patients with chronic obstructive pulmonary disease. To that end, we examined whether the expression levels of these genes were under genetic control in lung tissue (n = 1,111). We then determined whether the mRNA levels of these genes in lung tissue (n = 727), small airway epithelial cells (n = 238), and peripheral blood (n = 620) were significantly related to lung function measurements. The expression of 63 of the 127 genes (50%) was under genetic control in lung tissue. The lung and epithelial mRNA expression of a subset of the emphysema-associated genes, including ASRGL1, LPHN2, and EDNRB, was strongly associated with lung function. In peripheral blood, the expression of 40 genes was significantly associated with lung function. Twenty-nine of these genes (73%) were also associated with lung function in lung tissue, but with the opposite direction of effect for 24 of the 29 genes, including those involved in hypoxia and B cell-related responses. The integrative genomics approach uncovered a significant overlap of emphysema genes associations with lung function between lung and blood with opposite directions between the two. These results support the use of peripheral blood to detect disease biomarkers.

Phenotyping Before Starting Treatment in COPD?

Chronic Obstructive Pulmonary Disease (COPD) is a heterogeneous and complex disease with great morbidity and mortality. Despite the new developments in the managements of COPD, it was recognized that not all patients benefit from the available medications. Therefore, efforts to identify subgroups or phenotypes had been made in order to predict who will respond to a class of drugs for COPD. This review will discuss phenotypes, endotypes, and subgroups such as the frequent exacerbator, the one with systemic inflammation, the fast decliner, ACOS, and the one with co-morbidities and their impact on therapy. It became apparent, that the "inflammatory" phenotypes: frequent exacerbator, chronic bronchitic, and those with a number of co-morbidities need inhaled corticosteroids; in contrast, the emphysematous type with dyspnea and lung hyperinflation, the fast decliner, need dual bronchodilation (deflators). However, larger, well designed studies clustering COPD patients are needed, in order to identify the important subgroups and thus, to lead to personalize management in COPD.

Identification of thyroxine-binding globulin as a candidate plasma marker of chronic obstructive pulmonary disease

Biomarkers for the management of chronic obstructive pulmonary disease (COPD) are limited. The aim of this study was to explore new plasma biomarkers in patients with COPD. Thyroxine-binding globulin (THBG) was initially identified by proteomics in a discovery panel and subsequently verified by enzyme-linked immunosorbent assay in another verification panel with a 1-year follow-up. THBG levels were elevated in patients with COPD (9.2±2.3 μg/mL) compared to those of the controls (6.6±2.0 μg/mL). Receiver operating characteristic curves suggested that THBG was able to slightly differentiate between patients with COPD and controls (area under the curve [AUC]: 0.814) and performed better if combined with fibrinogen (AUC: 0.858). THBG was more capable of distinguishing Global Initiative for Obstructive Lung Disease stages I–III and IV (AUC: 0.851) compared with fibrinogen (AUC 0.582). THBG levels were negatively associated with predicted percentage forced expiratory volume in 1 s and positively related to predicted percentage residual volume, RV/percentage total lung capacity, and percentage low-attenuation area. COPD patients with higher baseline THBG levels had a greater risk of acute exacerbation (AE) than those with lower THBG levels (P=0.014, by Kaplan–Meier curve; hazard ratio: 4.229, by Cox proportional hazards model). In summary, THBG is a potential plasma biomarker of COPD and can assist in the management of stable stage and AEs in COPD patients.

Identification of subtypes in subjects with mild-to-moderate airflow limitation and its clinical and socioeconomic implications

PURPOSE

The purpose of this study was to identify subtypes in patients with mild-to-moderate airflow limitation and to appreciate their clinical and socioeconomic implications.

METHODS

Subjects who were aged ≥20 years and had forced expiratory volume in 1 second (FEV₁) ≥60% predicted and FEV₁/forced vital capacity <0.7 were selected from the fourth Korea National Health and Nutrition Examination Survey (KNHANES) in 2007-2012. The data were merged to the National Health Insurance reimbursement database during the same period. k-Means clustering was performed to explore subtypes. For clustering analysis, six key input variables - age, body mass index (BMI), FEV₁% predicted, the presence or absence of self-reported wheezing, smoking status, and pack-years of smoking - were selected.

RESULTS

Among a total of 2,140 subjects, five groups were identified through k-means clustering, namely putative "near-normal (n=232)," "asthmatic (n=392)," "chronic obstructive pulmonary disease (COPD) (n=37)," "asthmatic-overlap (n=893)," and "COPD-overlap (n=586)" subtypes. Near-normal group showed the oldest mean age (72±7 years) and highest FEV₁ (102%±8% predicted), and asthmatic group was the youngest (46±9 years). COPD and COPD-overlap groups were male predominant and all current or ex-smokers. While asthmatic group had the lowest prescription rate despite the highest proportion of self-reported wheezing, COPD, asthmatic-overlap, and COPD-overlap groups showed high prescription rate of respiratory medicine. Although COPD group formed only 1.7% of total subjects, they showed the highest mean medical cost and health care utilization, comprising 5.3% of the total medical cost. When calculating a ratio of total medical expense to household income, the mean ratio was highest in the COPD group.

CONCLUSION

Clinical and epidemiological heterogeneities of subjects with mild-to-moderate airflow limitation and a different level of health care utilization by each subtype are shown. Identification of a subtype with high health care demand could be a priority for effective utilization of limited resources.

Fetuin-B (FETUB): a Plasma Biomarker Candidate Related to the Severity of Lung Function in COPD

Biomarkers for the progression of lung function in COPD are currently scarce. Plasma fetuin-B (FETUB) was identified by iTRAQ-based proteomics and was verified by ELISA in another group. Information regarding acute exacerbation (AE) was collected in a one-year follow-up programme. FETUB concentrations (1652 ± 427 ng/ml) were greater in COPD patients than in controls (1237 ± 77 ng/ml). The concentrations of FETUB in GOLD II (1762 ± 427 ng/ml), III (1650 ± 375 ng/ml) and IV (1800 ± 451 ng/ml) groups were greater than those in the controls (1257 ± 414 ng/ml) and the GOLD I (1345 ± 391 ng/ml) group. ROCs indicated that FETUB distinguished COPD patients from controls (AUC 0.747, 95% CI: 0.642–0.834) and also GOLD II, III and IV from GOLD I COPD patients (AUC: 0.770, 95% CI: 0.634–0.874). The combination of FETUB and fibrinogen performed better (AUC: 0.804, 95% CI: 0.705–0.881). FETUB also predicted the occurrence of AE (AUC: 0.707, 95% CI: 0.566–0.824) or frequent AE (AUC: 0.727, 95% CI: 0.587–0.840). FETUB concentrations were negatively correlated with FEV1%pred (r = −0.446, p = 0.000) and positively correlated with RV%pred (r = 0.317, p = 0.004), RV/TLC% (r = 0.360, p = 0.004), CT emphysema% (r = 0.322, p = 0.008) and grades of lung function (r = 0.437, p = 0.000). In conclusion, FETUB is likely to assist the diagnosis and management of COPD as a complement for other markers.

COPD disease severity and the risk of venous thromboembolic events: a matched case-control study

BACKGROUND

It is generally accepted that people with chronic obstructive pulmonary disease (COPD) are at increased risk of vascular disease, including venous thromboembolism (VTE). While it is plausible that the risk of arterial and venous thrombotic events is greater still in certain subgroups of patients with COPD, such as those with more severe airflow limitation or more frequent exacerbations, these associations, in particular those between venous events and COPD severity or exacerbation frequency, remain largely untested in large population cohorts.

METHODS

A total of 3,594 patients with COPD with a first VTE event recorded during January 1, 2004 to December 31, 2013, were identified from the Clinical Practice Research Datalink dataset and matched on age, sex, and general practitioner practice (1:3) to patients with COPD with no history of VTE (n=10,782). COPD severity was staged by degree of airflow limitation (ie, GOLD stage) and by COPD medication history. Frequent exacerbators were defined as patients with COPD with ≥ 2 exacerbations in the 12-month period prior to their VTE event (for cases) or their selection as a control (for controls). Conditional logistic regression was used to estimate the association between disease severity or exacerbation frequency and VTE.

RESULTS

After additional adjustment for nonmatching confounders, including body mass index, smoking, and heart-related comorbidities, there was evidence for an association between increased disease severity and VTE when severity was measured either in terms of lung function impairment (odds ratio [OR]moderate:mild =1.16; 95% confidence intervals [CIs] =1.03, 1.32) or medication usage (ORsevere:mild/moderate =1.17; 95% CIs =1.06, 1.26). However, there was no evidence to suggest that frequent exacerbators were at greater risk of VTE compared with infrequent exacerbators (OR =1.06; 95% CIs =0.97, 1.15).

CONCLUSION

COPD severity defined by airflow limitation or medication usage, but not exacerbation frequency, appears to be associated with VTE events in people with COPD. This finding highlights the disconnect between disease activity and severity in COPD.

A Framework for the Development and Interpretation of Different Sepsis Definitions and Clinical Criteria

Although sepsis was described more than 2,000 years ago, and clinicians still struggle to define it, there is no "gold standard," and multiple competing approaches and terms exist. Challenges include the ever-changing knowledge base that informs our understanding of sepsis, competing views on which aspects of any potential definition are most important, and the tendency of most potential criteria to be distributed in at-risk populations in such a way as to hinder separation into discrete sets of patients. We propose that the development and evaluation of any definition or diagnostic criteria should follow four steps: 1) define the epistemologic underpinning, 2) agree on all relevant terms used to frame the exercise, 3) state the intended purpose for any proposed set of criteria, and 4) adopt a scientific approach to inform on their usefulness with regard to the intended purpose. Usefulness can be measured across six domains: 1) reliability (stability of criteria during retesting, between raters, over time, and across settings), 2) content validity (similar to face validity), 3) construct validity (whether criteria measure what they purport to measure), 4) criterion validity (how new criteria fare compared to standards), 5) measurement burden (cost, safety, and complexity), and 6) timeliness (whether criteria are available concurrent with care decisions). The relative importance of these domains of usefulness depends on the intended purpose, of which there are four broad categories: 1) clinical care, 2) research, 3) surveillance, and 4) quality improvement and audit. This proposed methodologic framework is intended to aid understanding of the strengths and weaknesses of different approaches, provide a mechanism for explaining differences in epidemiologic estimates generated by different approaches, and guide the development of future definitions and diagnostic criteria.

Biomarker Development for Chronic Obstructive Pulmonary Disease. From Discovery to Clinical Implementation

Chronic obstructive pulmonary disease (COPD) is one of the major causes of morbidity and mortality in the world. Regrettably, there are no biomarkers to objectively diagnose COPD exacerbations, which are the major drivers of hospitalization and deaths from COPD. Moreover, there are no biomarkers to guide therapeutic choices or to risk stratify patients for imminent exacerbations and no objective biomarkers of disease activity or disease progression. Although there has been a tremendous investment in COPD biomarker discovery over the past 2 decades, clinical translation and implementation have not matched these efforts. In this article, we outline the challenges of biomarker development in COPD and provide an overview of a developmental pipeline that may be able to surmount these challenges and bring novel biomarker solutions to accelerate therapeutic discoveries and to improve the care and outcomes of the millions of individuals worldwide with COPD.

MACVIA-ARIA Sentinel NetworK for allergic rhinitis (MASK-rhinitis): the new generation guideline implementation

Several unmet needs have been identified in allergic rhinitis: identification of the time of onset of the pollen season, optimal control of rhinitis and comorbidities, patient stratification, multidisciplinary team for integrated care pathways, innovation in clinical trials and, above all, patient empowerment. MASK-rhinitis (MACVIA-ARIA Sentinel NetworK for allergic rhinitis) is a simple system centred around the patient which was devised to fill many of these gaps using Information and Communications Technology (ICT) tools and a clinical decision support system (CDSS) based on the most widely used guideline in allergic rhinitis and its asthma comorbidity (ARIA 2015 revision). It is one of the implementation systems of Action Plan B3 of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA). Three tools are used for the electronic monitoring of allergic diseases: a cell phone-based daily visual analogue scale (VAS) assessment of disease control, CARAT (Control of Allergic Rhinitis and Asthma Test) and e-Allergy screening (premedical system of early diagnosis of allergy and asthma based on online tools). These tools are combined with a clinical decision support system (CDSS) and are available in many languages. An e-CRF and an e-learning tool complete MASK. MASK is flexible and other tools can be added. It appears to be an advanced, global and integrated ICT answer for many unmet needs in allergic diseases which will improve policies and standards.

Accelerated extracellular matrix turnover during exacerbations of COPD

Background

Exacerbations of chronic obstructive pulmonary disease (COPD) contribute significantly to disease progression. However, the effect on tissue structure and turnover is not well described. There is an urgent clinical need for biomarkers of disease activity associated with disease progression. Extracellular matrix (ECM) turnover reflects activity in tissues and consequently assessment of ECM turnover may serve as biomarkers of disease activity. We hypothesized that the turnover of lung ECM proteins were altered during exacerbations of COPD.

Methods

69 patients with COPD hospitalised for an exacerbation were recruited at admission and returned for a 4 weeks follow-up. Competitive ELISAs measuring circulating protein fragments in serum or plasma assessed the formation and degradation of collagen types III (Pro-C3 and C3M, respectively), IV (P4NP 7S and C4M, respectively), and VI (Pro-C6 and C6M, respectively), and degradation of elastin (ELM7 and EL-NE) and versican (VCANM).

Results

Circulating levels of C3M, C4M, C6M, ELM7, and EL-NE were elevated during an exacerbation of COPD as compared to follow-up (all P <0.0001), while VCANM levels were decreased (P <0.0001). Pro-C6 levels were decreased and P4NP 7S levels were elevated during exacerbation (P <0.0001). Pro-C3 levels were unchanged. At time of exacerbation, degradation/formation ratios were increased for collagen types III and VI and decreased for collagen type IV.

Conclusions

Exacerbations of COPD resulted in elevated levels of circulating fragments of structural proteins, which may serve as markers of disease activity. This suggests that patients with COPD have accelerated ECM turnover during exacerbations which may be related to disease progression.

Neutrophil-to-lymphocyte ratio, calprotectin and YKL-40 in patients with chronic obstructive pulmonary disease: correlations and 5-year mortality - a cohort study

Background

Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation and progressive decline in pulmonary function. Neutrophil-to-lymphocyte ratio (NLR), YKL-40 and calprotectin are biomarkers of inflammation and predict mortality in patients with different inflammatory diseases. We aimed to investigate the correlation between levels of these three biomarkers and neutrophil granulocyte and lymphocyte count in patients with moderate to very severe COPD stratified by use of systemic glucocorticoids. Furthermore, we studied the ability of these biomarkers to predict all-cause mortality.

Methods

386 patients with moderate to very severe COPD were followed prospectively for 10 years. Patients were divided into two groups according to systemic glucocorticoid use at baseline. Correlations between biomarkers were assessed by Spearman’s Rho, and mortality was evaluated in uni- and multivariate Cox regression analyses with hazard ratios (HR) and 95% confidence intervals (CI).

Results

Plasma calprotectin was positively correlated with neutrophil granulocyte count and NLR. No significant association was found between plasma YKL-40 and the cellular biomarkers, irrespective of glucocorticoid treatment. In the group not treated with systemic glucocorticoids, plasma calprotectin [HR 1.002 (95% CI 1.000 – 1.004)], NLR [HR 1.090 (1.036 – 1.148)] and lymphocyte count [HR 0.667 (0.522 – 0.851)] were significantly associated with higher mortality. In the group treated with systemic glucocorticoids, higher plasma YKL-40 was significantly associated with mortality in univariate Cox regression analysis [HR 1.006 (1.003 – 1.008)].

Conclusions

Calprotectin was related to neutrophil granulocyte count and NLR in patients with moderate to very severe COPD in stable phase and not in treatment with systemic glucocorticoids. Lymphopenia, higher plasma calprotectin and higher NLR were independent predictors of increased all-cause mortality in this group. Our data also suggests that treatment with systemic glucocorticoids has a significant impact on the ability of inflammatory biomarkers to predict all-cause mortality.

Trial registration

ClinicalTrials.gov NCT00132860.

Fusion of the 1H NMR data of serum, urine and exhaled breath condensate in order to discriminate chronic obstructive pulmonary disease and obstructive sleep apnea syndrome

Chronic obstructive pulmonary disease, COPD, affects the condition of the entire human organism and causes multiple comorbidities. Pathological lung changes lead to quantitative changes in the composition of the metabolites in different body fluids. The obstructive sleep apnea syndrome, OSAS, occurs in conjunction with chronic obstructive pulmonary disease in about 10-20 % of individuals who have COPD. Both conditions share the same comorbidities and this makes differentiating them difficult. The aim of this study was to investigate whether it is possible to diagnose a patient with either COPD or the OSA syndrome using a set of selected metabolites and to determine whether the metabolites that are present in one type of biofluid (serum, exhaled breath condensate or urine) or whether a combination of metabolites that are present in two biofluids or whether a set of metabolites that are present in all three biofluids are necessary to correctly diagnose a patient. A quantitative analysis of the metabolites in all three biofluid samples was performed using ¹H NMR spectroscopy. A multivariate bootstrap approach that combines partial least squares regression with the variable importance in projection score (VIP-score) and selectivity ratio (SR) was adopted in order to construct discriminant diagnostic models for the groups of individuals with COPD and OSAS. A comparison study of all of the discriminant models that were constructed and validated showed that the discriminant partial least squares model using only ten urine metabolites (selected with the SR approach) has a specificity of 100 % and a sensitivity of 86.67 %. This model (AUC_test = 0.95) presented the best prediction performance. The main conclusion of this study is that urine metabolites, among the others, present the highest probability for correctly identifying patents with COPD and the lowest probability for an incorrect identification of the OSA syndrome as developed COPD. Another important conclusion is that the changes in the metabolite levels of exhaled breath condensates do not appear to be specific enough to differentiate between patients with COPD and OSAS.

The concept of control of COPD in clinical practice

Treatment of chronic obstructive pulmonary disease (COPD) requires a personalized approach according to the clinical characteristics of the patients, the level of severity, and the response to the different therapies. Furthermore, patients with the same level of severity measured by the degree of airflow obstruction or even with multidimensional indices may have very different symptoms and limitations for daily activities. The concept of control has been extensively developed in asthma but has not been defined in COPD. Here, we propose a definition of COPD control based on the concepts of impact and stability. Impact is a cross-sectional concept that can be measured by questionnaires such as the COPD Assessment Test or the Clinical COPD Questionnaire. Alternatively, impact can be assessed by the degree of dyspnea, the use of rescue medication, the level of physical activity, and sputum color. Stability is a longitudinal concept that requires the absence of exacerbations and deterioration in the aforementioned variables or in the COPD Assessment Test or Clinical COPD Questionnaire scores. Control is defined by low impact (adjusted for severity) and stability. The concept of control in COPD can be useful in the decision making regarding an increase or decrease in medication in the stable state.

Should we view chronic obstructive pulmonary disease differently after ECLIPSE? A clinical perspective from the study team

RATIONALE

Chronic obstructive pulmonary disease (COPD) seems to be a heterogeneous disease with a variable course.

OBJECTIVES

We wished to characterize the heterogeneity and variability of COPD longitudinally.

METHODS

In the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study of 2,164 patients with clinically stable COPD, 337 smokers with normal lung function, and 245 never-smokers, we measured a large number of clinical parameters, lung function, exercise tolerance, biomarkers, and amount of emphysema by computed tomography. All three groups were followed for 3 years.

MEASUREMENTS AND MAIN RESULTS

We found a striking heterogeneity among patients with COPD, with poor correlations between FEV1, symptoms, quality of life, functional outcomes, and biomarkers. Presence of systemic inflammation was found in only a limited proportion of patients, and did not relate to baseline characteristics or disease progression, but added prognostic value for predicting mortality. Exacerbations tracked over time and added to the concept of the "frequent exacerbator phenotype." Disease course was very variable, with close to a third of patients not progressing at all. Risk factors for 3-year change in both FEV1 and lung density were assessed. For FEV1 decline, continued smoking and presence of emphysema were the strongest predictors of progression; club cell protein was found to be a potential biomarker for disease activity. For progression of emphysema, the strongest predictors were continued smoking and female sex.

CONCLUSIONS

By following a large, well characterized cohort of patients with COPD over 3 years, we have a clearer picture of a heterogeneous disease with clinically important subtypes ("phenotypes") and a variable and not inherently progressive course. Clinical trial registered with www.clinicaltrials.gov (NCT00292552).

Microfibrillar-associated protein 4: a potential biomarker of chronic obstructive pulmonary disease

BACKGROUND

Microfibrillar-associated protein 4 (MFAP4) is a matricellular glycoprotein that co-localises with elastic fibres and is highly expressed in the lungs. The aim of this study was to test the hypothesis that plasma MFAP4 (pMFAP4) reflects clinical outcomes in chronic obstructive pulmonary disease (COPD).

METHODS

pMFAP4 was measured by an AlphaLISA immunoassay in stable COPD (n = 69) at baseline and at follow-up until 24 months after inclusion and in acute exacerbations of COPD (AECOPD) (n = 14) at baseline and until 6 months after inclusion.

RESULTS

The majority of patients (89%) were in GOLD II and III. Multiple linear regressions showed positive associations between pMFAP4 and the Global initiative for Obstructive Lung Disease (GOLD) grade (p = 0.01), modified Medical Research Council score (p < 0.0001) and BODE index (p = 0.04). Negative associations were found with 6-min walking distance (p = 0.04) and bronchodilator-induced reversibility (p = 0.02). The pMFAP4 levels varied less than 25% between the baseline and a 3 month follow-up in 83% of the patients. The pMFAP4 levels appeared unaffected in the acute phase of severe AECOPD but rose to an increased stable level within one month after hospitalization.

CONCLUSION

Increased pMFAP4 was associated to the severity in COPD and has the potential to serve as a stable disease biomarker. This observation warrants confirmation in a larger longitudinal COPD population.

The PROTECCT-M study: a cohort study investigating associations between novel specific biomarkers, patient-related, healthcare system markers and the trajectory of COPD patients treated in primary care

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) is the most common severe chronic disease in primary care. It is typically diagnosed at a late stage, and it is also difficult to predict its trajectory and hence to tailor treatment and rehabilitation. The overall aim is to study determinants of exacerbations of COPD treated in primary care and to study, if the prognosis is related to patient-related, healthcare system markers or levels of the potential biomarkers such as microfibrillar-associated protein 4 (MFAP4) and surfactant protein D (SP-D). Furthermore, we aim to establish a cohort of COPD patients treated in Danish primary care comprising register data, data captured from the GPs' electronic patient record system (EPR) and a biobank in order to make analyses on factors associated with different tractories of COPD treated in primary care.

METHODS/DESIGN

A cohort study of incident and prevalent COPD patients treated and followed by their GPs using data capture, which is a computer system collecting data from the GPs' own EPR and transferring them to the Danish General Practice Research Database. The participating COPD patients were investigated at a baseline consultation by their own GP, and the results were registered using a pop-up menu by the GP. During the consultation blood samples were taken and the patients were given a questionnaire. The patients will then be followed prospectively at yearly consultations and in between these consultations by means of the data capture system. The collected data will also be combined with register data from other sources. The data collection started in December 2012, and so far 30 practices with 77 GPs have included about 350 patients. The study aims to include 2000 patients till the end of 2016, and after that to continue to collect data on these patients using the data capture system.

DISCUSSION

The GP currently lacks tools to predict trajectory of their COPD patients. The measurement of lung function only reflects loss of lung capacity and not disease activity. Use of biomarkers for detection of early COPD could be a possible way of predicting trajectory to aid both the GP and his/her patients. This study aims to provide evidence of determinants of a COPD trajectory, including novel specific biomarkers and other patient- and healthcare system-related markers.

TRIAL REGISTRATION

ClinicalTrials.gov Protocol Registration System, Identifier: NCT01698151.

Design of the Subpopulations and Intermediate Outcomes in COPD Study (SPIROMICS)

Subpopulations and Intermediate Outcomes in COPD Study (SPIROMICS) is a multicentre observational study of chronic obstructive pulmonary disease (COPD) designed to guide future development of therapies for COPD by providing robust criteria for subclassifying COPD participants into groups most likely to benefit from a given therapy during a clinical trial, and identifying biomarkers/phenotypes that can be used as intermediate outcomes to reliably predict clinical benefit during therapeutic trials. The goal is to enrol 3200 participants in four strata. Participants undergo a baseline visit and three annual follow-up examinations, with quarterly telephone calls. Adjudication of exacerbations and mortality will be undertaken.

The path to personalised medicine in COPD

Our understanding of chronic obstructive pulmonary disease (COPD) has changed dramatically over the past two decades. We have moved from an airflow limitation-centric view to the realisation that COPD is a complex and heterogeneous disease, which leads inevitably to the need for personalising the assessment and treatment of patients with COPD. This review provides a brief perspective of the extraordinary transition that the COPD field has experienced in the last two decades, and speculates on how it should/can move forward in the near future in order to really achieve the goal of personalising COPD medicine in the clinic.

The role of microparticles in chronic obstructive pulmonary disease

Accumulating evidence suggests that cell injury in lung tissues is closely connected to disease progression in chronic obstructive pulmonary disease (COPD). Microparticles (MPs) are shed membrane vesicles that are released from platelets, leukocytes, red blood cells, and endothelial cells when these cells are activated or undergo apoptosis under inflammatory conditions. Based on increasing evidence that endothelial injury in the pulmonary capillary vasculature leads to lung destruction, and because cardiovascular diseases are the main cause of death among individuals with COPD, endothelial MPs (EMPs) are now receiving attention as potential biomarkers for COPD. There are eight types of EMPs which are defined by the presence of different endothelial markers on the cell membrane: vascular endothelial-cadherin; platelet endothelial cell adhesion molecule; melanoma cell adhesion molecule; E-selectin; CD51; CD105; von Willebrand factor; and CD143 EMPs. Vascular endothelial-cadherin, platelet endothelial cell adhesion molecule, and E-selectin EMPs are increased in patients with stable COPD and are further increased in patients with exacerbated COPD compared to non-COPD patients. In addition, the levels of these three EMPs in patients with stable COPD are significantly correlated with lung destruction and airflow limitation. These results indicate that endothelial injury is closely connected to the pathophysiology of COPD. Interestingly, the variations in the levels of the eight EMP subtypes were not identical with changes in patient condition. Although the clinical significance of the differences in these eight EMP subtypes remains unclear, evaluating the expression pattern of endothelial antigens on circulating MPs might predict the presence and degree of endothelial injury in COPD patients. In addition, circulating MPs are proposed to have several physiological functions in vivo, such as intercellular crosstalk; the increase in EMPs in COPD seems to play a role in the pathophysiology of this disease.

Annual FEV1 changes and numbers of circulating endothelial microparticles in patients with COPD: a prospective study

OBJECTIVE

Growing evidence suggests that endothelial injury is involved in the pathophysiology of chronic obstructive pulmonary disease (COPD). Circulating endothelial microparticles (EMPs) increase in patients with COPD because of the presence of endothelial injury. We examined the relationship between EMP number and changes in forced expiratory volume in 1 s (FEV1) in patients with COPD.

DESIGN

Prospective study.

SETTING

One hospital in Japan.

PARTICIPANTS

A total 48 outpatients with stable COPD coming to the hospital from September 2010 to September 2011.

PRIMARY AND SECONDARY OUTCOMES MEASURED

Blood samples were collected and vascular endothelial (VE)-cadherin EMPs (CD144+ EMPs), E-selectin EMPs (CD62E+ EMPs) and platelet endothelial cell adhesion molecule EMPs (CD31+/CD41- EMPs) were measured using fluorescence-activated cell sorting. Annual FEV1 changes were evaluated using FEV1 data acquired a year before and a year after sample collection.

RESULTS

The number of E-selectin and VE-cadherin EMPs showed significant negative correlations with annual FEV1 changes (rs=-0.65, p<0.001, rs=-0.43, p=0.003, respectively). Leucocyte counts tended to be correlated with annual FEV1 changes, but this correlation was not significant (rs=-0.28, p=0.057). There were significant differences in annual FEV1 changes between with and without history of frequent exacerbation (p=0.006), and among Global Initiative for Chronic Obstructive Lung Disease (GOLD) stages (p=0.009). Multiple linear regression analysis revealed E-selectin EMP to be the only significant parameter associated with annual FEV1 changes, independent of VE-cadherin EMP, GOLD stages, leucocyte counts, and history of frequent exacerbation. Receiver operating characteristic curves showed the optimum E-selectin EMP cut-off level for prediction of rapid FEV1 decline (>66 mL/year) to be 153.0/µL (areas under curve 0.78 (95% CI 0.60 to 0.89); sensitivity, 67%; specificity, 81%).

CONCLUSIONS

The high E-selectin EMP levels in stable patients with COPD are predictive of rapid FEV1 decline.

TRIAL REGISTRATION NUMBER

UMIN000005168.

Disease 'activity', 'severity' and 'impact': interrelationships in COPD; is a measure of disease 'activity' the Holy Grail for COPD, or a variable impossible to quantify?

It is increasingly recognised that new measures of disease 'activity' for COPD are required, however the relationship between markers of disease 'activity', 'severity' and 'impact' though closely linked, is poorly understood. Additionally, while change in markers of disease 'severity' (e.g. change in FEV1) may be considered a marker of disease 'activity', these quantify a single aspect of disease 'activity' in COPD rather than measuring the overall disease process and this has stimulated the search for new biomarkers of COPD that reflect the 'activity' of the disease process. The ideal biomarker of disease 'activity' would be stable with respect to time since measurement at any time point would then relate to subsequent disease progression. This would allow the influence of a therapeutic intervention to be assessed early, facilitating both phase 2 and 3 clinical trials. Although a number of potential biomarkers of COPD disease 'activity' have been studied, to date none have been shown to conclusively relate to disease progression and the stability of underlying disease 'activity' therefore requires further consideration. Interestingly, while the variability of disease 'activity' of COPD is rarely mentioned in the current literature, and there is uncertainty whether 'activity' is constant or highly variable, there are clues from available data as discussed in the current article. Finally we consider how markers of disease 'activity', 'severity' and 'impact' may relate, which is of utmost importance in the ongoing search for new biomarkers in COPD and a greater understanding of the pathogenesis of the disease process.

Prognostic value of C-reactive protein, leukocytes, and vitamin d in severe chronic obstructive pulmonary disease

Inflammatory biomarkers predict mortality and hospitalisation in chronic obstructive pulmonary disease (COPD). Yet, it remains uncertain if biomarkers in addition to reflecting disease severity add new prognostic information on severe COPD. We investigated if leukocytes, C-reactive protein (CRP), and vitamin D were independent predictors of mortality and hospitalisation after adjusting for disease severity with an integrative index, the i-BODE index. In total, 423 patients participating in a pulmonary rehabilitation programme, with a mean value of FEV₁ of 38% of predicted, were included. Mean followup was 45 months. During the follow-up period, 149 deaths (35%) were observed and 330 patients (78.0%) had at least one acute hospitalisation; 244 patients (57.7%) had at least one hospitalisation due to an exacerbation of COPD. In the analysis (Cox proportional hazards model) fully adjusted for age, sex, and i-BODE index, the hazard ratio for 1 mg/L increase in CRP was 1.02 (P = 0.003) and for 1 × 10⁹/L increase in leukocytes was 1.43 (P = 0.03). Only leukocyte count was significantly associated with hospitalisation. Vitamin D was neither associated with mortality nor hospitalisation. Leukocytes and CRP add little information on prognosis and vitamin D does not seem to be a useful biomarker in severe COPD in a clinical setting.

Sputum PGP is reduced by azithromycin treatment in patients with COPD and correlates with exacerbations

RATIONALE

Proline-glycine-proline (PGP), a neutrophil chemoattractant derived from the enzymatic breakdown of collagen, is elevated in sputum of patients with chronic obstructive pulmonary disease (COPD) and may contribute to disease progression. Whether sputum levels of PGP respond to therapy for COPD or predict outcomes is unknown.

OBJECTIVES

We conducted a study ancillary to a multicenter trial of the efficacy of azithromycin treatment for 1 year in preventing COPD exacerbations to test whether sputum levels of PGP were altered by treatment or associated with exacerbation frequency.

METHODS

We collected remnant sputa from trial participants and assayed them in a blinded fashion for PGP, myeloperoxidase and matrix metalloproteinase (MMP)-9 and for the ability to generate PGP from collagen ex vivo. Once the parent trial was unblinded, the results were correlated with use of azithromycin or placebo and exacerbations in participants.

RESULTS

Azithromycin treatment significantly reduced sputum levels of PGP and myeloperoxidase in patients with COPD, particularly with increased duration of therapy. We found no difference in sputum MMP-9 or PGP generation between participants taking azithromycin or placebo. Sputum PGP levels were highest around the time of an exacerbation and declined with successful treatment.

CONCLUSIONS

These data support a role for PGP in the airway and parenchymal neutrophilic inflammation that drives COPD progression and exacerbations, and provide new information on the anti-inflammatory properties of macrolides. PGP may have potential as a target for novel anti-inflammatory therapies in COPD and as a biomarker for clinical trials.

Calprotectin--a marker of mortality in COPD? Results from a prospective cohort study

Calprotectin comprises more than 45% of the cytosolic content of neutrophil granulocytes. Because pathogenesis, disease activity and disease progression in COPD are believed to be partly dependent of neutrophil driven inflammation we decided to investigate whether plasma level of calprotectin (p-calprotectin) was associated with all-cause mortality in patients with COPD. We measured p-calprotectin in blood samples from 460 patients with moderate to very severe COPD in stable phase. Patients were stratified into three groups according to p-calprotectin level. Outcome measure was all-cause mortality. Analyses were adjusted for factors known to influence mortality using a Cox regression analysis. We found a time dependent correlation between p-calprotectin levels and mortality during the first 5 years of follow-up. Increasing levels of p-calprotectin were associated with concomitant increases in mortality from HR 1.56 (CI 95%: 1.03 -2.38) at calprotectin between 100 -200 ng/ml to HR 2.02 (CI 95%: 1.27-3.19) at calprotectin >200 ng/ml. P-calprotectin could be a useful marker of all-cause mortality in patients suffering from moderate to very severe COPD.

The value of periodic spirometry for early recognition of long-term excessive lung function decline in individuals

OBJECTIVE

To establish the value of workplace spirometry monitoring methods for early recognition of long-term excessive lung function decline in individuals.

METHODS

Sensitivity, specificity, and positive likelihood ratio were calculated to determine the predictive value of the linear regression slope and limits of longitudinal decline for early prediction of long-term excessive forced expiratory volume in 1 second (FEV1) decline (> 90 mL/yr established over 9 to 11 years) in ongoing spirometry monitoring programs (firefighters and construction workers) and a historical program (paper-pulp mill workers). The longitudinal limits account for the expected FEV1 within-person variability.

RESULTS

The longitudinal limits achieved clinical "usefulness" (positive likelihood ratio 10 or higher) from the fourth to fifth year of follow-up, whereas the linear regression slope was less useful. The usefulness depended on data precision and measurement frequency.

CONCLUSION

The limits of longitudinal decline are more useful for early recognition of long-term excessive FEV1 decline than the linear regression slope.

Comparison of arterial and venous blood biomarker levels in chronic obstructive pulmonary disease

PURPOSE

The development of novel biomarkers is an unmet need in chronic obstructive pulmonary disease (COPD). Arterial blood comes directly from the lung and venous blood drains capillary beds of the organ or tissue supplied. We hypothesized that there would be a difference in levels of the biomarkers metalloproteinase 9 (MMP-9), vascular endothelial growth factor A (VEGF-A) and interleukin 6 (IL-6) in arterial compared with venous blood. 

METHODS

Radial artery and brachial vein blood samples were taken simultaneously in each of 12 patients with COPD and seven controls with normal lung function. Circulating immunoreactive MMP-9, VEGF-A and IL-6 levels in serum were measured using quantitative enzyme-linked immunosorbent assays. RESULTS were compared using a Student's paired t test. The study was powered to determine whether significant differences in cytokine levels were present between paired arterial and venous blood samples.  

RESULTS

In the 12 patients with COPD, four were female, and age ranged 53-85 years, mean age 69 years. Three patients in the control group were female, with age range 46-84 years, mean age 64.7 years. In the COPD group, three patients had mild, five moderate and four severe COPD. No significant difference was found between arterial and venous levels of MMP-9, VEGF-A or IL-6. 

CONCLUSIONS

In this pilot study, levels of the measured biomarkers in arterial compared with venous blood in both COPD patients and healthy controls did not differ. This suggests that as we continue to chase the elusive biomarker in COPD as a potential tool to measure disease activity, we should focus on venous blood for this purpose.

A randomised, placebo-controlled, dose-finding study of AZD9668, an oral inhibitor of neutrophil elastase, in patients with chronic obstructive pulmonary disease treated with tiotropium

AZD9668 is a fully reversible, selective, oral inhibitor of neutrophil elastase, a protease implicated in chronic obstructive pulmonary disease (COPD). Efficacy, safety and tolerability of AZD9668 (5, 20 and 60 mg bid) were compared with placebo in a randomised, double-blind, placebo-controlled, 12-week, Phase IIb trial (NCT00949975: approved by an Investigational Review Board), in patients with symptomatic COPD receiving maintenance tiotropium. The primary endpoint was pre-bronchodilator forced expiratory volume in 1 second (FEV₁). Secondary endpoints included forced vital capacity and inspiratory capacity, peak expiratory flow, Breathlessness, Cough and Sputum Scale score, exercise capacity, quality of life (QoL), exacerbation assessments, safety and pharmacokinetics. Exploratory endpoints included inflammatory and tissue degradation biomarkers. A total of 838 patients were randomised to AZD9668 5 mg bid (212 patients), 20 mg bid (206 patients), 60 mg bid (202 patients) or placebo (218 patients). AZD9668 showed no effect on lung function, respiratory signs and symptoms, QoL or biomarkers. At end of treatment, the change in mean pre-bronchodilator FEV₁ for AZD9668 60 mg bid compared with placebo was 0.00L (95% confidence interval: -0.05, 0.04; p = 0.873). Overall, AZD9668 was well tolerated; the numbers of patients with adverse events (AEs), serious AEs and AEs leading to discontinuation were similar in each of the four study groups. AZD9668 60 mg bid showed no clinical benefit and no effect on biomarkers of inflammation or tissue degradation when added to tiotropium in patients with COPD. These results raise important questions for future investigation of anti-inflammatory and disease-modifying agents in patients with COPD.