Inflammatory biomarkers improve clinical prediction of mortality in chronic obstructive pulmonary disease

Characterization of the changes in eicosanoid profiles of activated macrophages treated with 20(S)-ginsenoside Rg3

In this study, we used ultra-performance liquid chromatography coupled with tandem mass spectrometry to assess the levels of eicosanoids from RAW264.7 macrophages treated with lipopolysaccharides (LPS) and 20(S)-ginsenoside Rg3 (Rg3). The production of nitric oxide (NO) and the secretion of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were increased in inflammatory macrophages treated with LPS. Rg3 treatment, however, decreased the levels of NO, TNF-α, and IL-6 in activated macrophages. Eicosanoids, known as major metabolites correlated with inflammation, have pro- or anti-inflammatory activities. For a detailed characterization of the eicosanoids altered by treatment with LPS and Rg3, the eicosanoids were profiled by multiple reaction monitoring. A total of 69 macrophage eicosanoids were analyzed and the profiling dataset was statistically analyzed. Principal component and hierarchical cluster analyses differentiated control cells from cells treated with LPS, Rg3, or LPS+Rg3 for 12 or 24h. Furthermore, 18 differentially regulated eicosanoids were found between macrophages treated with LPS for 24h and those treated with LPS+Rg3 for 24h (fold change>2, p value<0.05). These results indicate that Rg3 alters eicosanoid metabolism in activated macrophages treated with LPS. Furthermore, we also identified several eicosanoids correlated with the anti-inflammatory activity of Rg3.

Differences in systemic inflammation between cigarette and biomass smoke-induced COPD

Background and objective

It is known that biomarkers of systemic inflammation are raised in COPD caused by tobacco (T-COPD) compared with healthy controls, but there is less information on the inflammatory status of subjects with COPD caused by biomass smoke (B-COPD). In addition, the possible (if any) differences in inflammation between both types of the disease are still not well known. The aim of this study was to assess the inflammatory profile in B-COPD and T-COPD.

Methods

A total of 20 subjects (15 men and five women) with T-COPD were matched one to one for sex, age and forced expiratory volume in 1 s (FEV₁) to 20 B-COPD patients. In all, 20 sex-matched healthy subjects with normal lung function without smoking history or biomass exposure were included as controls. The following biomarkers were measured: exhaled nitric oxide, serum IL-6, IL-8, IL-5, IL-13, periostin, surfactant protein-P, TNF-α, IgE, erythrocyte sedimentation rate, C-reactive protein and fibrinogen. Complete blood count was also obtained.

Results

The age of the subjects was 70.2±7.9 years and FEV₁% was 56.2%±14.6%. Most inflammatory biomarkers were higher in both types of COPD than in healthy controls. IL-6, IL-8 and IL-5 were significantly higher in T-COPD than in B-COPD, without other significant differences.

Conclusion

Both types of COPD are associated with high levels of systemic inflammation biomarkers. T-COPD patients have a higher systemic inflammatory status than the patients with B-COPD.

[Systemic inflammatory profile of smokers with and without COPD]

INTRODUCTION

Studies comparing the systemic inflammatory profiles of smokers with and without COPD present discordant findings.

AIM

To compare the systemic inflammatory profile of smokers with and without COPD.

METHODS

This is a cross-sectional comparative study. Two groups of active smokers of more than 10 pack-years were included: 56 consecutives stable COPD (postbronchodilator FEV₁/FVC<0.70) and 32 consecutives non-COPD (postbronchodilator FEV₁/FVC≥0.70). Smoking and clinical, anthropometric and spirometric data were noted. The following blood biomarkers were identified: leukocytes, hemoglobin, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR). According to the levels (normal/abnormal) of these markers, two groups of smokers were formed. Quantitative and qualitative data were expressed, respectively, as means±SD and percentages.

RESULTS

Compared to the non-COPD group, the COPD group was older (56±12 vs. 65±8 years) and had a higher smoking consumption (30±18 vs. 52±31 pack-years). Compared to the non-COPD group, the COPD group had higher values of CRP (2.06±1.24 vs. 11.32±11.03mg/L), of ESR (9.59±8.29 vs. 15.96±11.56), of IL-6 (9.28±4.69 vs. 20.27±5.31ng/L) and of TNF-α (18.38±7.98ng/L vs. 8.62±3.72ng/L). Compared to the non-COPD group, the COPD group included higher percentages of smokers with elevated CRP (0 % vs. 32 %), with leukocytosis (6 % vs. 16 %), with higher levels of IL-6 (81 % vs. 98 %) or TNF-α (91 % vs. 100 %).

CONCLUSION

Smokers with COPD, compared to smokers free from COPD, have a marked systemic inflammation.

Selective ATP-Binding Cassette Subfamily C Gene Expression and Proinflammatory Mediators Released by BEAS-2B after PM2.5, Budesonide, and Cotreated Exposures

ATP-binding cassette subfamily C (ABCC) genes code for phase III metabolism proteins that translocate xenobiotic (e.g., particulate matter 2.5 (PM2.5)) and drug metabolites outside the cells. IL-6 secretion is related with the activation of the ABCC transporters. This study assesses ABCC1-4 gene expression changes and proinflammatory cytokine (IL-6, IL-8) release in human bronchial epithelial cells (BEAS-2B) exposed to PM2.5 organic extract, budesonide (BUD, used to control inflammation in asthmatic patients), and a cotreatment (Co-T: PM2.5 and BUD). A real-time PCR assay shows that ABCC1 was upregulated in BEAS-2B exposed after 6 and 7 hr to PM2.5 extract or BUD but downregulated after 6 hr of the Co-T. ABCC3 was downregulated after 6 hr of BUD and upregulated after 6 hr of the Co-T exposures. ABCC4 was upregulated after 5 hr of PM2.5 extract, BUD, and the Co-T exposures. The cytokine assay revealed an increase in IL-6 release by BEAS-2B exposed after 5 hr to PM2.5 extract, BUD, and the Co-T. At 7 hr, the Co-T decreases IL-6 release and IL-8 at 6 hr. In conclusion, the cotreatment showed an opposite effect on exposed BEAS-2B as compared with BUD. The results suggest an interference of the BUD therapeutic potential by PM2.5.

Effect of carbocisteine on patients with COPD: a systematic review and meta-analysis

BACKGROUND

COPD is the fourth leading cause of death in the world. It is a common, progressive, treatable and preventable disease. The exacerbation of COPD is associated with the peripheral muscle force, forced expiratory volume in 1 second (FEV1), the quality of life and mortality. Many studies indicated that the mucoactive medicines could reduce the exacerbations of COPD. This study summarized the efficacy of carbocisteine as a treatment for COPD.

METHODS

We searched the randomized controlled trials (RCTs) following electronic bibliographic databases: MedLine, Embase, Cochrane Library and Web of Science. We additionally searched gray literature database: OpenSIGLE. We also additionally searched the clinical trial registers: ClinicalTrials.gov register and International Clinical Trials Registry Platform Search Portal. We used RCTs to assess the efficacy of the treatments. We included studies of adults (older than 18 years) with COPD. We excluded studies that were published as protocol or written in non-English language (Number 42016047078).

FINDINGS

Our findings included data from four studies involving 1,357 patients. There was a decrease in the risk of the rate of total number of exacerbations with carbocisteine compared with placebo (-0.43; 95% confidence interval [CI] -0.57, -0.29, P<0.01). Carbocisteine could also improve the quality of life (-6.29; 95% CI -9.30, -3.27) and reduce the number of patients with at least one exacerbation (0.86; 95% CI 0.78, 0.95) compared with placebo. There was no significant difference in the FEV1 and adverse effects and the rate of hospitalization.

INTERPRETATION

Long-term use of carbocisteine (500 mg TID) may be associated with lower exacerbation rates, the smaller number of patients with at least one exacerbation and higher quality of life of patients with COPD.

Systemic White Blood Cell Count as a Biomarker Associated with Severity of Chronic Obstructive Lung Disease

Background

Chronic obstructive pulmonary disease (COPD), is a chronic inflammatory disorder. We evaluated whether white blood cell (WBC) count, is associated with the severity of COPD, independent of other inflammatory conditions, such as metabolic syndrome.

Methods

The WBC counts were compared between 1227 COPD patients and 8679 non-COPD adults older than 40. The relationships between the WBC count, lung function, and symptoms score in COPD patients, were determined, using general linear regression analyses.

Results

The WBC count was negatively associated with forced vital capacity (FVC, L), FVC (% predicted), forced expiry volume in one second (FEV₁, L), and FEV₁ (% predicted) in COPD patients. Additionally, the WBC count was independently associated with the quality of life measure, by EQ5D-index score. However, this relationship between WBC count, and disease severity, was not significant in current smokers, because of the confounding effect of smoking, on the WBC count.

Conclusion

The WBC count is associated with current smoking status and COPD severity, and a risk factor for poor lung function, and quality of life, especially in non-currently smoking COPD patients. The WBC count can be used, as an easily measurable COPD biomarker.

Effects of exposure to biomass burning on pulmonary inflammatory markers and pulmonary function in individuals with COPD

INTRODUCTION

Pulmonary rehabilitation (PR) has many benefits for individuals with COPD. However, it is not clear whether PR could prevent the hazards of air pollution exposure. This study aimed to analyze the effects of biomass burning exposure on pulmonary inflammatory markers and pulmonary function in individuals with COPD, participants and non-participants of PR.

METHODS

35 subjects were divided into three groups: individuals with COPD who received PR (G1, n=15), those who did not (G2, n=10), and a control group composed of healthy individuals without COPD (CG, n=10). Measurements of lung function and concentrations of IL-6, IL-10, and TNF-α in exhaled breath condensate samples were collected. The assessment and concentrations of particulate matter (PM₁₀), nitrogen dioxide (NO₂), ozone (O₃), temperature (T), and relative air humidity (RAH) were recorded in biomass burning and non-burning periods.

RESULTS

There was a significant increase in the concentrations of air pollutants in the biomass burning period. In this period, an increase in IL-6 (G1p=0.041, G2 p=.012), and a reduction in the FEV₁/FVC ratio (G1p=0.021, G2 p=.007) were observed in individuals with COPD. In G1, the increase in IL-6 concentrations correlated positively with O₃ (r=0.693; p=.006), and negatively with RAH (r=-0.773; p=.003) in the burning period.

CONCLUSIONS

Individuals with COPD exposed to biomass burning demonstrated increased pulmonary inflammation and a reduction in the FEV₁/FVC ratio, regardless of their engagement in PR.

Multiple biomarkers predict disease severity, progression and mortality in COPD

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease characterized by multiple subtypes and variable disease progression. Blood biomarkers have been variably associated with subtype, severity, and disease progression. Just as combined clinical variables are more highly predictive of outcomes than individual clinical variables, we hypothesized that multiple biomarkers may be more informative than individual biomarkers to predict subtypes, disease severity, disease progression, and mortality.

METHODS

Fibrinogen, C-Reactive Protein (CRP), surfactant protein D (SP-D), soluble Receptor for Advanced Glycation Endproducts (sRAGE), and Club Cell Secretory Protein (CC16) were measured in the plasma of 1465 subjects from the COPDGene cohort and 2746 subjects from the ECLIPSE cohort. Regression analysis was performed to determine whether these biomarkers, individually or in combination, were predictive of subtypes, disease severity, disease progression, or mortality, after adjustment for clinical covariates.

RESULTS

In COPDGene, the best combinations of biomarkers were: CC16, sRAGE, fibrinogen, CRP, and SP-D for airflow limitation (p < 10^-4), SP-D, CRP, sRAGE and fibrinogen for emphysema (p < 10^-3), CC16, fibrinogen, and sRAGE for decline in FEV₁ (p < 0.05) and progression of emphysema (p < 10^-3), and all five biomarkers together for mortality (p < 0.05). All associations except mortality were validated in ECLIPSE. The combination of SP-D, CRP, and fibrinogen was the best model for mortality in ECLIPSE (p < 0.05), and this combination was also significant in COPDGene.

CONCLUSION

This comprehensive analysis of two large cohorts revealed that combinations of biomarkers improve predictive value compared with clinical variables and individual biomarkers for relevant cross-sectional and longitudinal COPD outcomes.

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.

Evaluation of platelet lymphocyte ratio and 90-day mortality in patients with acute exacerbation of chronic obstructive pulmonary disease

BACKGROUND

Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) have high mortality and health care costs. The platelet to lymphocyte ratio (PLR) is a marker of inflammation and has been reported to be elevated in patients with AECOPD compared to stable state. In this study, we sought to evaluate the association of the PLR in patients with AECOPD with 90-day mortality.

METHODS

We conducted a retrospective cohort study of patients admitted to our institution with a primary diagnosis of AECOPD between January 2014 and July 2014. Blood test results on admission were recorded. The primary outcomes were 90-day mortality.

RESULTS

One hundred and eighty-one AECOPD patients were considered for the study. Death had occurred in 16 (9%) patients within 90 days of hospital discharge. Univariable analysis identified age, haemoglobin, neutrophil count, and urea level, neutrophil lymphocyte ratio (NLR) and PLR as being associated with increased 90-day mortality. Multivariable logistic regression analysis variables demonstrated that only PLR (P=0.03) was significantly associated with death at 90 days. Receiver operator characteristic analysis identified PLR ≥235 had a sensitivity of 63% and specificity of 74% in predicting 90-day mortality. PLR was ≥235 was also associated with worse survival (days) [mean ± standard deviation (SD): PLR ≥235 vs. PLR <235: 512±358 vs. 626±346, P=0.004].

CONCLUSIONS

A PLR ≥235 was significantly associated with 90-day mortality, which may provide prognostic guidance to clinicians.

St George's Respiratory Questionnaire Score Predicts Outcomes in Patients with COPD: Analysis of Individual Patient Data in the COPD Biomarkers Qualification Consortium Database

Background: We aimed to estimate the usefulness of a disease specific health status measure, the St George's Respiratory Questionnaire (SGRQ), to predict outcomes in patients with chronic obstructive pulmonary disease (COPD). Methods: Individual patient-data of 12043 patients from long-term randomized clinical trials (2-4 years' duration) in the COPD Biomarkers Qualification Consortium database were analyzed. The adverse COPD outcomes were: exacerbations of COPD, hospital admissions due to exacerbation and all-cause mortality. Cox proportional hazards regression was used to calculate adjusted hazard ratios (HR) and 95% confidence intervals (CIs) for quartiles of SGRQ scores at baseline and time to first event, and time from first to second event, where appropriate. Results: The risk of adverse COPD outcomes increased with each increasing quartile of SGRQ score for all time to first event analyses. When comparing the lowest versus the highest quartile, the event risk (HRs [95% CIs]) increased by 40% for exacerbations (1.40 [1.29, 1.51]); 2-fold for hospital admissions (2.01 [1.78, 2.28]) and more than 2-fold for all-cause mortality (2.30 [1.91, 2.78]). For second event analyses in a subset of eligible patients, these trends persisted albeit with reduced risk estimates for exacerbations. Conclusions: Among patients with COPD, health status measured by a SGRQ score predicted exacerbations of COPD, hospital admissions due to exacerbations and their recurrence and death after adjustment. These data support the rationale for a health status measure use as a drug development tool and suggest that a health status measure may also have a role in risk assessment for COPD patients in routine medical care.

The use of cellular and molecular biomarkers to manage COPD exacerbations

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) exacerbations are a common cause of respiratory morbidity and mortality, and have various etiologies. Multiple cellular and molecular biomarkers have been associated with exacerbations. Quantitative sputum cell counts are able to identify the presence and type of bronchitis, which is an important contributor to exacerbations. Their utility to monitor bronchitis and to help treat exacerbations has been evaluated, yet they are not used in routine clinical practice. Areas covered: This review will provide a brief summary of biomarkers utilized in COPD, with a focus on the application of cellular markers for the management of exacerbations. A case study will demonstrate the application of these methods. With quantitative sputum cell counts, the presence of eosinophilic bronchitis predicts corticosteroid-responsiveness, while neutrophilic bronchitis identifies infection and suggests the need for antibiotics. Gastroesophageal reflux-related aspiration and heart failure can also be identified by examining sputum. Expert commentary: Quantitative sputum cytometry is an essential tool in the management of exacerbations of COPD, particularly those prone to frequent exacerbations. Treatment based on sputum cell counts is superior to current guideline-based recommendations to prevent future exacerbations and hospitalizations in observational and single-centre controlled trials. Large multicentre clinical trials are necessary to confirm this.

C-reactive protein level predicts mortality in COPD: a systematic review and meta-analysis

The prognostic role of baseline C-reactive protein (CRP) in chronic obstructive pulmonary disease (COPD) is controversial. In order to clarify this issue, we performed a systematic review and meta-analysis to assess the predictive effect of baseline CRP level in COPD patients. 15 eligible articles focusing on late mortality in COPD were included in our study. We performed a random-effects meta-analysis, and assessed heterogeneity and publication bias. We pooled hazard ratio (HR) estimates and their 95% confidence intervals on mortality for the comparison between the study-specific highest category of CRP level versus the lowest category. In overall analysis, elevated baseline CRP levels were significantly associated with higher mortality (HR 1.53, 95% CI 1.32-1.77, I²=68.7%, p<0.001). Similar results were observed across subgroups. However, higher mortality risk was reported in studies using a cut-off value of 3 mg·L^-1 (HR 1.61, 95% CI 1.12-2.30) and in those enrolling an Asiatic population (HR 3.51, 95% CI 1.69-7.31). Our analysis indicates that baseline high CRP level is significantly associated with higher late mortality in patients with COPD. Further prospective controlled studies are needed to confirm these data.

End-of-life prognostic indicators in patients with COPD: Part 1

In the UK, chronic respiratory diseases cause 13% of adult disability. The major chronic respiratory disease is chronic obstructive pulmonary disease (COPD), a condition involving chronic airway inflammation that causes airflow obstruction and destruction of lung tissue. This leads to a progressive loss of respiratory membrane, which accounts for the clinical manifestation of COPD, which is difficulty maintaining sufficient gas exchange to meet metabolic demands. The primary cause is smoking, with the vast majority of COPD patients having a past or present history of smoking. However exposure to industrial pollutants is also a contributing factor, as is a rare genetic predisposition to developing COPD.

Risk factors for FEV1 decline in mild COPD and high-risk populations

Background

Early diagnosis of COPD is often not achieved due to limited recognition and limited access to the pulmonary function test. Our hypothesis was that lung function decline may be different between populations with mild COPD and those who are at high risk and do not receive treatment.

Patients and methods

Subjects with mild COPD and those from a high-risk COPD population were recruited from a community-based COPD epidemiological study after obtaining consent. Baseline clinical characteristics, symptom questionnaire, spirometry, low-dose computed tomography (LDCT) chest scan, and blood plasma biomarker data were collected initially and then 1 year later.

Results

A total of 617 participants were recruited, and 438 eventually completed the first-year follow-up visit; 72 participants (46 males) were in the mild COPD group, and 225 participants (165 males) were in the high-risk group. The mean forced expiratory volume in the first second of expiration (FEV₁) decline in the mild COPD group was 129 mL, which was significantly higher than the 30 mL decline in the high-risk population group (P=0.005). Group category (odds ratio [OR] =0.230) and COPD Assessment Test (CAT) score (OR =9.912) were independent risk factors for an FEV₁% predicted decline of >15% for all participants. In the mild COPD group, patients with a higher CAT (OR =5.310) and Emphysema Index (OR =5.681) were associated with a FEV₁% predicted decline of >15% at the first-year follow-up. No factor showed a significantly predictive effect on FEV₁ decline in the high-risk COPD group.

Conclusion

Group category was an independent influential factor associated with FEV₁ decline.

Evaluation of plasma leptin, tumor necrosis factor-α, and prealbumin as prognostic biomarkers during clinical recovery from acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Inflammatory and nutritional biomarkers have an important bearing on outcomes of acute exacerbations of chronic obstructive pulmonary disease (AECOPD), but the temporal profile of these compounds during an acute episode is unclear.

PATIENTS AND METHODS

Plasma leptin, prealbumin, and tumor necrosis factor-alpha (TNF-α) were estimated at baseline and before hospital discharge in patients with AECOPD.

RESULTS

A total of 82 patients were evaluated (66 males; mean (standard deviation) age, 61.6 (10.1) years. Of these, 74 subjects (90.2%) were current or former smokers, with median (range) pack-years of 15 (0-96), duration of COPD of 8 years (range, 2-25 years) and duration of current symptoms being 5 days (range, 1-30 days). Majority (41.5%) had type I (severe) exacerbation. During the current episode, 46 patients (58.9%) required mechanical ventilation for a median of 6 days (range, 1-34). The median duration of hospital stay was 13 days, (range, 1-110). At discharge, significant reduction was observed in dyspnea, total leukocyte count, erythrocyte sedimentation rate (ESR), partial pressure of carbon dioxide, hemoglobin, urea, creatinine, potassium, aspartate transferase, and TNF-α levels compared to baseline, whereas arterial pH, PO₂, serum albumin, prealbumin, and leptin significantly improved. No difference was seen in leptin, prealbumin, and TNF-α between patients with mild/moderate and severe exacerbation, or between patients who required or did not require mechanical ventilation. Change in leptin correlated with body mass index and change in ESR; no associations were observed between leptin, prealbumin, and TNF-α with other clinico-laboratory variables.

CONCLUSION

Plasma levels of novel inflammatory and nutritional biomarkers, i.e., leptin, TNF-α, and prealbumin are altered in AECOPD episodes and lag behind other parameters during recovery. These biomarkers are not reliable predictors of clinical outcomes in these patients.

Combined Bone Marrow-Derived Mesenchymal Stromal Cell Therapy and One-Way Endobronchial Valve Placement in Patients with Pulmonary Emphysema: A Phase I Clinical Trial

One-way endobronchial valves (EBV) insertion to reduce pulmonary air trapping has been used as therapy for chronic obstructive pulmonary disease (COPD) patients. However, local inflammation may result and can contribute to worsening of clinical status in these patients. We hypothesized that combined EBV insertion and intrabronchial administration of mesenchymal stromal cells (MSCs) would decrease the inflammatory process, thus mitigating EBV complications in severe COPD patients. This initial study sought to investigate the safety of this approach. For this purpose, a phase I, prospective, patient-blinded, randomized, placebo-controlled design was used. Heterogeneous advanced emphysema (Global Initiative for Chronic Lung Disease [GOLD] III or IV) patients randomly received either allogeneic bone marrow-derived MSCs (10⁸ cells, EBV+MSC) or 0.9% saline solution (EBV) (n = 5 per group), bronchoscopically, just before insertion of one-way EBVs. Patients were evaluated 1, 7, 30, and 90 days after therapy. All patients completed the study protocol and 90-day follow-up. MSC delivery did not result in acute administration-related toxicity, serious adverse events, or death. No significant between-group differences were observed in overall number of adverse events, frequency of COPD exacerbations, or worsening of disease. Additionally, there were no significant differences in blood tests, lung function, or radiological outcomes. However, quality-of-life indicators were higher in EBV + MSC compared with EBV. EBV + MSC patients presented decreased levels of circulating C-reactive protein at 30 and 90 days, as well as BODE (Body mass index, airway Obstruction, Dyspnea, and Exercise index) and MMRC (Modified Medical Research Council) scores. Thus, combined use of EBV and MSCs appears to be safe in patients with severe COPD, providing a basis for subsequent investigations using MSCs as concomitant therapy. Stem Cells Translational Medicine 2017;6:962-969.

Systemic IL-6 Effector Response in Mediating Systemic Bone Loss Following Inhalation of Organic Dust

Airway and skeletal diseases are prominent among agriculture workers. Repetitive inhalant exposures to agriculture organic dust extract (ODE) induces bone deterioration in mice; yet the mechanisms responsible for connecting the lung-bone inflammatory axis remain unclear. We hypothesized that the interleukin (IL)-6 effector response regulates bone deterioration following inhalant ODE exposures. Using an established intranasal inhalation exposure model, wild-type (WT) and IL-6 knockout (KO) mice were treated daily with ODE or saline for 3 weeks. ODE-induced airway neutrophil influx, cytokine/chemokine release, and lung pathology were not reduced in IL-6 KO animals compared to WT mice. Utilizing micro-computed tomography, analysis of tibia showed that loss of bone mineral density, volume, and deterioration of bone micro-architecture, and mechanical strength induced by inhalant ODE exposures in WT mice were absent in IL-6 KO animals. Compared to saline treatments, bone-resorbing osteoclasts and bone marrow osteoclast precursor populations were also increased in ODE-treated WT but not IL-6 KO mice. These results show that the systemic IL-6 effector pathway mediates bone deterioration induced by repetitive inhalant ODE exposures through an effect on osteoclasts, but a positive role for IL-6 in the airway was not demonstrated. IL-6 might be an important link in explaining the lung-bone inflammatory axis.

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.

Natural history and risk stratification of patients undergoing non-invasive ventilation in a non-ICU setting for severe COPD exacerbations

Non-invasive ventilation (NIV) delivered in an intensive care unit (ICU) has become the cornerstone in the treatment of patients with severe chronic obstructive pulmonary disease (COPD) exacerbations. A trend towards managing these patients in non-ICU setting has emerged in recent years, although out-of-hospital survival by this approach and how to prognosticate it is unknown. We aimed to investigate these issues. We consecutively recruited 100 patients (49 males; median age 82 years) who received NIV treatment for acute respiratory failure due to COPD exacerbation in non-ICU medical wards of our hospital, between November 2008 and July 2012. We assessed survival (both in-hospital and out-of-hospital) of all these patients, and analyzed baseline parameters in a Cox proportional hazards model to develop a prognostic score. The median survival in the study population was 383 days (240-980). Overall survival rates were 71.0, 65.3, and 52.7 % at 1, 3, and 12 months, respectively. Age >85 years, a history of heart disorders and a neutrophil count ≥10 × 10(9) were associated with higher mortality at Cox's analysis (χ (2) = 35.766, p = 0.0001), and were used to build a prognostic score (NC85). The presence of two or more factors determined the deepest drop in survival (when NC85 ≥2, mortality at 1, 3, and 12 was 60.7, 70.4, and 77.2 %, respectively, while when NC85 = 0 were 4.0, 4.0, and 14.0 %). A simple model, based on three variables (age, neutrophil count and history of heart disease), accurately predicts survival of COPD patients receiving NIV in a non-ICU setting.

Probing Cellular and Molecular Mechanisms of Cigarette Smoke-Induced Immune Response in the Progression of Chronic Obstructive Pulmonary Disease Using Multiscale Network Modeling

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory disorder characterized by progressive destruction of lung tissues and airway obstruction. COPD is currently the third leading cause of death worldwide and there is no curative treatment available so far. Cigarette smoke (CS) is the major risk factor for COPD. Yet, only a relatively small percentage of smokers develop the disease, showing that disease susceptibility varies significantly among smokers. As smoking cessation can prevent the disease in some smokers, quitting smoking cannot halt the progression of COPD in others. Despite extensive research efforts, cellular and molecular mechanisms of COPD remain elusive. In particular, the disease susceptibility and smoking cessation effects are poorly understood. To address these issues in this work, we develop a multiscale network model that consists of nodes, which represent molecular mediators, immune cells and lung tissues, and edges describing the interactions between the nodes. Our model study identifies several positive feedback loops and network elements playing a determinant role in the CS-induced immune response and COPD progression. The results are in agreement with clinic and laboratory measurements, offering novel insight into the cellular and molecular mechanisms of COPD. The study in this work also provides a rationale for targeted therapy and personalized medicine for the disease in future.

What is the impact of different spirometric criteria on the prevalence of spirometrically defined COPD and its comorbidities? Results from the population-based KORA study

Background

There is an ongoing debate about the appropriate spirometric criterion for airway obstruction to detect COPD. Furthermore, the association of different criteria with comorbidity prevalence and inflammatory biomarkers in advanced age is unclear.

Materials and methods

Spirometry was performed in a population-based study (n=2,256) covering an age range of 41–90 years. COPD was spirometrically determined either by a fixed ratio (FR) of <0.7 for forced expiratory volume in 1 second (FEV₁)/forced vital capacity (FVC) or by FEV₁/FVC below the lower limit of normal (LLN). Comorbidity prevalences and circulating biomarker levels (C-reactive protein [CRP], interleukin [IL]-6) were compared between subjects with or without COPD by the two criteria using logistic and multiple regression models, adjusting for sex and age.

Results

The prevalence of spirometrically defined COPD by FR increased with age from 10% in subjects aged <65 years to 26% in subjects aged ≥75 years. For LLN-defined COPD, it remained below 10% for all age groups. Overall, COPD diagnosis was not associated with specific comorbidities, except for a lower prevalence of obesity in both FR- and LLN-defined cases. Both CRP and IL-6 tended to be higher in cases by both criteria.

Conclusion

In a population-based cohort of adults up to the age of 90 years, the prevalence of spirometrically defined COPD was higher for the FR criterion than for the LLN criterion. This difference increased with age. Neither prevalences of common comorbidities nor levels of the biomarkers, CRP or IL-6, were conclusively associated with the selection of the COPD criterion. Results have to be considered in light of the predominantly mild cases of airway obstruction in the examined study population.

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.

Role of CD69 in the pathogenesis of elastase-induced pulmonary inflammation and emphysema

Cluster of differentiation 69 (CD69), known as an early activation marker of lymphocytes, has been demonstrated to regulate inflammatory events in various disease models. Although the increased number of CD69-expressed T lymphocytes in the lungs of patients with chronic obstructive pulmonary disease (COPD) has been reported, a functional role of CD69 in the pathogenesis of COPD remains unknown. To address to this question, CD69-deficient (CD69KO) mice and wild-type (WT) mice were subjected to a mouse model of porcine pancreatic elastase (PPE)-induced pulmonary inflammation and emphysema. In the two genotypes, PPE increased counts of macrophages, neutrophils and lymphocytes in bronchoalveolar lavage fluid (BALF) and induced emphysematous changes in the lung, whereas those two pathological signs were significantly enhanced in CD69KO mice compared to WT mice. Moreover, the PPE-induced levels of IL-17 and IL-6 in BALF were significantly higher in CD69KO mice than in WT mice at the acute inflammatory phase. Immunofluorescent studies showed that IL-17 and IL-6 were predominantly expressed in CD4⁺ and γδ T cells and macrophages, respectively. Concomitant administration of IL-17- and IL-6-neutralizing antibodies significantly attenuated the PPE-induced emphysematous changes in the two genotypes. These findings suggest that CD69 negatively regulates the development of PPE-induced emphysema in part at least through modulating function of IL-17-producing T cells.

Inflammatory and immunological profiles in patients with COPD: relationship with FEV 1 reversibility

OBJECTIVE:

To determine whether COPD severity correlates with sputum cell counts, atopy, and asthma.

METHODS:

This was a cross-sectional study involving 37 patients with COPD and 22 healthy subjects with normal lung function (controls). Sputum cell counts were determined by microscopy after centrifugation of samples. Skin prick tests were performed, and serum cytokines were determined by ELISA.

RESULTS:

Patients were stratified by bronchodilator response: a non-reversible airflow limitation (nonRAL) group comprised 24 patients showing no significant post-bronchodilator change in FEV1; and a partially reversible airflow limitation (partialRAL) group comprised 13 patients showing FEV1 reversibility (post-bronchodilator FEV1 increase ≥ 12%). The proportion of eosinophils in sputum was higher in the partialRAL group than in the nonRAL group (p < 0.01), and there was an inverse correlation between the proportion of eosinophils and FEV1 (p < 0.05). However, none of the patients had a history of asthma and skin prick test results did not differ between the two groups. In the patient sputum samples, neutrophils predominated. Serum levels of TNF, IL-6, IL-8, and RANTES (CCL5) were higher in patients than in controls (p < 0.001) but did not differ between the two patient groups.

CONCLUSIONS:

COPD patients with partial FEV1 reversibility appear to have higher sputum eosinophil counts and greater airway hyperresponsiveness than do those with no FEV1 reversibility. However, we found that COPD severity did not correlate with atopy or with the cytokine profile.

OBJETIVO:

Determinar se a gravidade da DPOC se correlaciona com a contagem de células no escarro, atopia e asma.

MÉTODOS:

Estudo transversal com 37 pacientes com DPOC e 22 indivíduos saudáveis com função pulmonar normal (controles). As contagens de células no escarro foram determinadas por microscopia após a centrifugação das amostras. Foram realizados testes cutâneos de puntura, e as citocinas séricas foram determinadas por ELISA.

RESULTADOS:

Os pacientes foram estratificados pela resposta ao broncodilatador: o grupo de limitação ao fluxo aéreo não reversível (LFAnr) envolveu 24 pacientes sem alteração significativa do VEF1 pós-broncodilatador, e o grupo de limitação ao fluxo aéreo parcialmente reversível (LFApr) envolveu 13 pacientes com reversibilidade do VEF1 (aumento do VEF1 pós-broncodilatador ≥ 12%). A proporção de eosinófilos no escarro foi maior no grupo LFApr do que no LFAnr (p < 0,01), e houve uma correlação inversa entre a proporção de eosinófilos e VEF1 (p < 0,05). Entretanto, nenhum dos pacientes apresentou histórico de asma e os resultados dos testes cutâneos não diferiram entre os dois grupos. Nas amostras de escarro dos pacientes, os neutrófilos predominaram. Os níveis séricos de TNF, IL-6, IL-8 e RANTES (CCL5) foram maiores nos pacientes que nos controles (p < 0,001), mas não diferiram entre os dois grupos de pacientes.

CONCLUSÕES:

Pacientes com DPOC e reversibilidade parcial do VEF1 parecem apresentar maiores contagens de eosinófilos no escarro e maior hiper-responsividade das vias aéreas que aqueles sem reversibilidade do VEF1. Entretanto, a gravidade da DPOC não se correlacionou com atopia ou perfil das citocinas.

The Gut-Liver-Lung Axis. Modulation of the Innate Immune Response and Its Possible Role in Chronic Obstructive Pulmonary Disease

Evidence from epidemiological studies suggests that a diet high in fiber is associated with better lung function and reduced risk of chronic obstructive pulmonary disease (COPD). The mechanism for this benefit remains unknown, but, as fiber is not absorbed by the gut, this finding suggests that the gut may play an active role in pathogenic pathways underlying COPD. There is a growing awareness that aberrant activity of the innate immune system, characterized by increased neutrophil and macrophage activation, may contribute to the development or progression of COPD. Innate immunity is modulated in large part by the liver, where hepatic cells function in immune surveillance of the portal circulation, as well as providing a rich source of systemic inflammatory cytokines and immune mediators (notably, IL-6 and C-reactive protein). We believe that the beneficial effect of dietary fiber on lung function is through modulation of innate immunity and subsequent attenuation of the pulmonary response to inflammatory stimuli, most apparent in current or former smokers. We propose that the "gut-liver-lung axis" may play a modifying role in the pathogenesis of COPD. In this review, we summarize lines of evidence that include animal models, large prospective observational studies, and clinical trials, supporting the hypothesis that the gut-liver-lung axis plays an integral part in the pathogenic mechanisms underlying the pathogenesis of COPD.

Association of the Neutrophil-to-Lymphocyte Ratio with Lung Function and Exacerbations in Patients with Chronic Obstructive Pulmonary Disease

BACKGROUND

The ratio of neutrophils to lymphocytes (NLR) is a widely available marker of inflammation. Several types of inflammatory cells and mediators have been found to be involved in the progression of chronic obstructive pulmonary disease (COPD). We sought to evaluate the association of the NLR with severity of airflow limitation and disease exacerbations in a COPD population.

METHODS

We analyzed 885 patients from the Korean COPD Subtype Study cohort that recruited subjects with COPD from 44 referral hospitals. We determined the relationship of NLR levels to severity of lung function using a linear regression model. In addition, we analyzed the experiences of COPD exacerbation according to the NLR quartiles.

RESULTS

NLR levels were inversely associated with severity of airflow limitation as measured by FEV1% predicted and absolute values after adjustments for age, gender, body mass index, pack-years of smoking, and the use of inhaled corticosteroid (P<0.001, respectively). In the multivariate binary regression model, the NLR 4th quartile (vs. 1st quartile) was found to be a significant predictor of exacerbations during 1-year follow-up (OR = 2.05, 95% CI = 1.03 to 4.06, P = 0.041). Adding an NLR to FEV1 significantly improved prediction for exacerbations during 1-year follow-up as measured by the net reclassification improvement (NRI = 7.8%, P = 0.032) and the integrated discrimination improvement (IDI = 0.014, P = 0.021).

CONCLUSIONS

The NLR showed a significant inverse relationship to airflow limitation and was a prognostic marker for future exacerbations in patients with COPD.

Functional capacity, health status, and inflammatory biomarker profile in a cohort of patients with chronic obstructive pulmonary disease

PURPOSE

Prior research has shown a significant relationship between 6-minute walking distance (6MWD) and health-related quality of life (HRQOL) in patients with chronic obstructive pulmonary disease (COPD). However, few studies have examined this relationship above and below the 350-m threshold that prognosticates survival and whether serum biomarkers could provide insight into the causes of quality-of-life differences above and below this threshold.

METHODS

Measures of lung function, 6MWD, and HRQOL were compared in patients with COPD. Differences in HRQOL domains and serum biomarkers were compared in patients whose 6MWD were > or < 350 m.

RESULTS

In patients walking < 350 m, scores in the physical domains of the SF-36 and the St. George's Respiratory Questionnaire (SGRQ) were significantly different from scores of their counterparts with greater 6MWD. However, there was no association between any biomarkers and the physical domains of the SF-36 and the SGRQ. In patients walking < 350 m, only the IL-8 levels were associated with lower scores in SF-36 domains of emotional role, pain, vitality, and mental health (average r = -0.702; P = .01). In contrast, in patients walking > 350 m, surfactant protein D levels were associated with higher SF-36 scores in general pain, vitality, and social functioning (average r = 0.42; P = .04).

CONCLUSIONS

In COPD, there is an association between 6MWD and the physical domains of the SF-36 and SGRQ in those patients walking < 350 m. The physical differences between patients walking < or > 350 m are not related to systemic inflammation. The association between interleukin 8 with nonphysical domains in patients with 6MWD < 350 m suggests that inflammation may play a larger role in the perceptive domain than previously recognized.

Novel relationships of markers of monocyte activation and endothelial dysfunction with pulmonary dysfunction in HIV-infected persons

OBJECTIVE

Chronic obstructive pulmonary disease is a common comorbidity in HIV, with prevalence and severity of disease incompletely explained by risk factors such as smoking and age. Unique HIV-associated factors, including microbial translocation, monocyte activation, and endothelial dysfunction, have been described in other comorbidities, but have not been investigated in relation to pulmonary abnormalities in HIV. This study assessed the relationship of these pathologic processes to pulmonary function in HIV-infected and uninfected individuals and determined if relationships were unique to HIV.

DESIGN

Longitudinal observational study.

METHODS

Total 274 participants completed pulmonary function testing. Markers of inflammation (IL-6, IL-8, and TNFα), microbial translocation (lipopolysaccharide, sCD14), monocyte activation (sCD163, sCD14, and IL-2 receptor), and endothelial dysfunction (endothelin-1) were measured at baseline. Cross-sectional and longitudinal analyses were performed, adjusting for pertinent covariates.

RESULTS

In HIV-infected individuals, higher IL-6 and endothelin-1 associated with worse forced expiratory volume in one second (FEV1) percentage-predicted, and higher sCD163 associated with worse FEV1/forced vital capacity. IL-6, TNFα, lipopolysaccharide, sCD163, IL-2 receptor, and endothelin-1 associated with diffusing impairment. sCD163 and endothelin-1 interacted with HIV status in relationship to pulmonary function. In HIV-infected individuals only, baseline endothelin-1 was associated with lower FEV1, and sCD163 and endothelin-1 were associated with lower diffusing capacity during follow-up.

CONCLUSION

Circulating markers of HIV-associated humoral abnormalities are associated with airflow obstruction and diffusing impairment and baseline measures of monocyte activation and endothelial dysfunction associate with lower pulmonary function over time in HIV-infected persons. These findings suggest mechanisms of the disproportionate burden of chronic obstructive pulmonary disease in HIV-infected persons.

Pulmonary surfactant mitigates silver nanoparticle toxicity in human alveolar type-I-like epithelial cells

Accompanying increased commercial applications and production of silver nanomaterials is an increased probability of human exposure, with inhalation a key route. Nanomaterials that deposit in the pulmonary alveolar region following inhalation will interact firstly with pulmonary surfactant before they interact with the alveolar epithelium. It is therefore critical to understand the effects of human pulmonary surfactant when evaluating the inhalation toxicity of silver nanoparticles. In this study, we evaluated the toxicity of AgNPs on human alveolar type-I-like epithelial (TT1) cells in the absence and presence of Curosurf(®) (a natural pulmonary surfactant substitute), hypothesising that the pulmonary surfactant would act to modify toxicity. We demonstrated that 20nm citrate-capped AgNPs induce toxicity in human alveolar type I-like epithelial cells and, in agreement with our hypothesis, that pulmonary surfactant acts to mitigate this toxicity, possibly through reducing AgNP dissolution into cytotoxic Ag(+) ions. For example, IL-6 and IL-8 release by TT1 cells significantly increased 10.7- and 35-fold, respectively (P<0.01), 24h after treatment with 25μg/ml AgNPs. In contrast, following pre-incubation of AgNPs with Curosurf(®), this effect was almost completely abolished. We further determined that the mechanism of this toxicity is likely associated with Ag(+) ion release and lysosomal disruption, but not with increased reactive oxygen species generation. This study provides a critical understanding of the toxicity of AgNPs in target human alveolar type-I-like epithelial cells and the role of pulmonary surfactant in mitigating this toxicity. The observations reported have important implications for the manufacture and application of AgNPs, in particular for applications involving use of aerosolised AgNPs.

IL6 Blockade Reprograms the Lung Tumor Microenvironment to Limit the Development and Progression of K-ras-Mutant Lung Cancer

Activating mutations of K-ras are the most common oncogenic alterations found in lung cancer. Unfortunately, attempts to target K-ras-mutant lung tumors have thus far failed, clearly indicating the need for new approaches in patients with this molecular profile. We have previously shown NF-κB activation, release of IL6, and activation of its responsive transcription factor STAT3 in K-ras-mutant lung tumors, which was further amplified by the tumor-enhancing effect of chronic obstructive pulmonary disease (COPD)-type airway inflammation. These findings suggest an essential role for this inflammatory pathway in K-ras-mutant lung tumorigenesis and its enhancement by COPD. Therefore, here we blocked IL6 using a monoclonal anti-IL6 antibody in a K-ras-mutant mouse model of lung cancer in the absence or presence of COPD-type airway inflammation. IL6 blockade significantly inhibited lung cancer promotion, tumor cell-intrinsic STAT3 activation, tumor cell proliferation, and angiogenesis markers. Moreover, IL6 inhibition reduced expression of protumor type 2 molecules (arginase 1, Fizz 1, Mgl, and IDO), number of M2-type macrophages and granulocytic myeloid-derived suppressor cells, and protumor T-regulatory/Th17 cell responses. This was accompanied by increased expression of antitumor type 1 molecule (Nos2), and antitumor Th1/CD8 T-cell responses. Our study demonstrates that IL6 blockade not only has direct intrinsic inhibitory effect on tumor cells, but also reeducates the lung microenvironment toward an antitumor phenotype by altering the relative proportion between protumor and antitumor immune cells. This information introduces IL6 as a potential druggable target for prevention and treatment of K-ras-mutant lung tumors. Cancer Res; 76(11); 3189-99. ©2016 AACR.

An official American Thoracic Society/European Respiratory Society statement: research questions in COPD

Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity, mortality and resource use worldwide. The goal of this official American Thoracic Society (ATS)/European Respiratory Society (ERS) Research Statement is to describe evidence related to diagnosis, assessment, and management; identify gaps in knowledge; and make recommendations for future research. It is not intended to provide clinical practice recommendations on COPD diagnosis and management.

Clinicians, researchers and patient advocates with expertise in COPD were invited to participate. A literature search of Medline was performed, and studies deemed relevant were selected. The search was not a systematic review of the evidence. Existing evidence was appraised and summarised, and then salient knowledge gaps were identified.

Recommendations for research that addresses important gaps in the evidence in all areas of COPD were formulated via discussion and consensus.

Great strides have been made in the diagnosis, assessment and management of COPD, as well as understanding its pathogenesis. Despite this, many important questions remain unanswered. This ATS/ERS research statement highlights the types of research that leading clinicians, researchers and patient advocates believe will have the greatest impact on patient-centred outcomes.

ATS/ERS statement highlighting research areas that will have the greatest impact on patient-centred outcomes in COPDhttp://ow.ly/LXW2J

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.

Challenges and Current Efforts in the Development of Biomarkers for Chronic Inflammatory and Remodeling Conditions of the Lungs

This review discusses biomarkers that are being researched for their usefulness to phenotype chronic inflammatory lung diseases that cause remodeling of the lung's architecture. The review focuses on asthma, chronic obstructive pulmonary disease (COPD), and pulmonary hypertension. Bio-markers of environmental exposure and specific classes of biomarkers (noncoding RNA, metabolism, vitamin, coagulation, and microbiome related) are also discussed. Examples of biomarkers that are in clinical use, biomarkers that are under development, and biomarkers that are still in the research phase are discussed. We chose to present examples of the research in biomarker development by diseases, because asthma, COPD, and pulmonary hypertension are distinct entities, although they clearly share processes of inflammation and remodeling.

A Randomized, Placebo-controlled Trial of Roflumilast. Effect on Proline-Glycine-Proline and Neutrophilic Inflammation in Chronic Obstructive Pulmonary Disease

RATIONALE

Roflumilast is a therapeutic agent in the treatment of chronic obstructive pulmonary disease (COPD). It has antiinflammatory effects; however, it is not known whether it can affect a biologic pathway implicated in COPD pathogenesis and progression. The self-propagating acetyl-proline-glycine-proline (AcPGP) pathway is a novel means of neutrophilic inflammation that is pathologic in the development of COPD. AcPGP is produced by extracellular matrix collagen breakdown with prolyl endopeptidase and leukotriene A4 hydrolase serving as the enzymes responsible for its production and degradation, respectively.

OBJECTIVES

We hypothesized that roflumilast would decrease AcPGP, halting the feed-forward cycle of inflammation.

METHODS

We conducted a single-center, placebo-controlled, randomized study investigating 12 weeks of roflumilast treatment added to current therapy in moderate-to-severe COPD with chronic bronchitis. Subjects underwent sputum and blood analyses, pulmonary function testing, exercise tolerance, and quality-of-life assessment at 0, 4, and 12 weeks.

MEASUREMENTS AND MAIN RESULTS

Twenty-seven patients were enrolled in the intention-to-treat analysis. Roflumilast treatment decreased sputum AcPGP by more than 50% (P < 0.01) and prolyl endopeptidase by 46% (P = 0.02), without significant improvement in leukotriene A4 hydrolase activity compared with placebo. Roflumilast also reduces other inflammatory markers. There were no significant changes in lung function, quality of life, or exercise tolerance between roflumilast- and placebo-treated groups.

CONCLUSIONS

Roflumilast reduces pulmonary inflammation through decreasing prolyl endopeptidase activity and AcPGP. As expected for lower AcPGP levels, markers of neutrophilic inflammation are blunted. Inhibiting this self-propagating pathway lessens the overall inflammatory burden, which may alter the natural history of COPD, including the risk of exacerbation. Clinical trial registered with www.clinicaltrials.gov (NCT 01572948).

Mindfulness meditation and the immune system: a systematic review of randomized controlled trials

Mindfulness meditation represents a mental training framework for cultivating the state of mindful awareness in daily life. Recently, there has been a surge of interest in how mindfulness meditation improves human health and well-being. Although studies have shown that mindfulness meditation can improve self-reported measures of disease symptomatology, the effect that mindfulness meditation has on biological mechanisms underlying human aging and disease is less clear. To address this issue, we conducted the first comprehensive review of randomized controlled trials examining the effects of mindfulness meditation on immune system parameters, with a specific focus on five outcomes: (1) circulating and stimulated inflammatory proteins, (2) cellular transcription factors and gene expression, (3) immune cell count, (4) immune cell aging, and (5) antibody response. This analysis revealed substantial heterogeneity across studies with respect to patient population, study design, and assay procedures. The findings suggest possible effects of mindfulness meditation on specific markers of inflammation, cell-mediated immunity, and biological aging, but these results are tentative and require further replication. On the basis of this analysis, we describe the limitations of existing work and suggest possible avenues for future research. Mindfulness meditation may be salutogenic for immune system dynamics, but additional work is needed to examine these effects.

Mental health, serum biomarkers and survival in severe COPD: a pilot study

Background

Chronic obstructive pulmonary disease (COPD) impairs physical status and impacts on mental health. This prospective study was designed to assess associations between mental health and systemic biomarkers, and their combined relationship with long-term survival in stable severe COPD.

Methods

Forty-five patients with severe but stable COPD (forced expiratory volume in 1 s of 29.8 (quartiles: 22.6; 41.4) %predicted) were assessed using the Hospital Anxiety and Depression Scale (HADS), the Patient Health Questionnaire (PHQ), St. George’s Respiratory Questionnaire and the State-Trait Anxiety Inventory (STAI). The following serum biomarkers were measured: 25-OH-cholecalciferol, C-reactive protein, erythrocyte sedimentation rate, leucocyte number, serum amyloid-A (SA-A), N-terminal pro-brain natriuretic peptide, troponin I, glycosylated haemoglobin, haemoglobin (Hb), haematocrit (Hc), creatinine and thyroid-stimulating hormone. Patients were followed-up for 36 months. Associations between aspects of mental health and biomarkers, and their utility as predictors of 3-year survival were evaluated by regression analyses.

Results

The prevalence of anxiety (HADS-A: 89.9 %), depression (HADS-D: 58.8 %; PHQ: 60.6 %), somatisation (PHQ-15: 81.8 %) and psychosocial stress (PHQ-stress: 60.6 %) was high. There was a significant positive association between the leucocyte count and SA-A level with STAI-trait anxiety (p = 0.03 and p = 0.005, respectively), and between leucocytes and PHQ-stress (p = 0.043). Hb and Hc were significantly negatively associated with HADS-depression (p = 0.041 and p = 0.031, respectively). Univariate Cox regression analyses revealed that leucocyte count (hazard ratio (HR) 2.976, 95 % CI 1.059-8.358; p = 0.038), and stress (HR 4.922, 95 % CI 1.06–22.848; p = 0.042) were linked to long-term survival. In multivariate Cox regression analyses, including known risk factors for survival in COPD, PHQ-stress (HR 45.63, 95 % CI 1.72–1,208.48; p = 0.022) remained significantly associated with survival.

Conclusion

In this pilot study different dimensions of mental health were correlated to serum biomarkers, probably reflecting systemic effects of COPD. While leucocyte number and PHQ-stress were associated with long-term survival in univariate analyses, PHQ-stress remained in multivariate analyses as independent prognostic factor.

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.