Airway inflammation contributes to health status in COPD: a cross-sectional study

Impact of Previous Occupational Exposure on Outcomes of Chronic Obstructive Pulmonary Disease

Occupational exposures have been regarded as a risk factor for the development of chronic obstructive pulmonary disease (COPD). However, there is little knowledge regarding the effect of occupational exposure on the treatment outcomes of COPD. Therefore, the aim of this study was to evaluate the question of whether occupational exposure can have a potential impact on COPD outcomes. Methods: Information regarding self-reported occupational exposure for 312 patients with COPD from the Korean Obstructive Lung Disease (KOLD) Cohort were included. A comparison of the rate of acute exacerbation, annual lung function change, and quality of life according to the presence or absence of occupational exposure was performed. Results: Seventy-six patients (24.4%) had experienced occupational exposure; chemical materials were most common. At enrollment, a higher COPD-specific version of the St. George Respiratory Questionnaire total score (39.7 ± 18.8 vs. 33.1 ± 17.6, p = 0.005) and a higher exacerbation history in the past year (30.3% vs. 17.5%, p = 0.017) were observed for patients with occupational exposure compared to those without occupational exposure. Furthermore, in the follow-up period, after adjusting for potential confounders, a higher frequency of acute exacerbation (odd ratio, 1.418; 95% confidence interval, 1.027–1.956; p = 0.033) and a more rapid decline in forced expiratory volume in 1 s (p = 0.009) was observed for COPD patients with occupational exposure compared to those without occupational exposure. Conclusions: In the KOLD cohort, worse outcomes in terms of exacerbation rate and change in lung function were observed for COPD patients with occupational exposure compared to those without occupational exposure. These findings suggest that occupational exposure not only is a risk factor for COPD but also might have a prognostic impact on COPD.

Effect of piperlongumine during exposure to cigarette smoke reduces inflammation and lung injury

Chronic obstructive pulmonary disease (COPD) is related to smoking and anti-inflammatory therapy is indicated. Among the mediators with anti-inflammatory properties, we highlight piperlongumine (PL), an alkaloid/amide of Piper longum. Here we evaluated the PL administration on an experimental model of respiratory inflammation resulting from exposure to cigarette smoke. Male Balb/c mice were exposed to burning of 10 commercial cigarettes, 2x/day, for five weeks on specific equipment. PL efficacy was evaluated in control, exposed to smoke without treatment and PL treated (2.0 mg/kg, 3x/week) groups. Animals were weighed and plethysmographic analyses performed at the end of the exposure protocol. Inflammatory cells were evaluated in the bronchoalveolar lavage (BAL) and hemoglobin and glucose in the blood. Lung fragments were processed for histopathological studies and AnxA1, COX-2, NF-kB and neutrophil elastase expressions. Plethysmography revealed that PL maintained pulmonary frequency, volume and ventilation parameters similar to controls, with respiratory volume reduction compared to untreated animals. Final weight was reduced in both exposed groups. PL decreased hemoglobin concentration, attenuated the reduction of glucose levels and reduced influx of lymphocytes, neutrophils and macrophages in BAL. Histopathologically occured infiltration of inflammatory cells, increase of the interalveolar septa and intra-alveolar spaces in untreated animals. But, PL administration recovered lung tissues and, immunohistochemically, promoted increased expression of AnxA1 and reduction of COX-2, NF-kB and neutrophil elastase. Together the results indicate that PL attenuates systemic and pulmonary inflammatory changes, partially by modulating the expression the endogenous AnxA1, and may represent a promising therapy in preventing the inflammation induced by cigarette smoke.

WNT/β-catenin signaling regulates cigarette smoke-induced airway inflammation via the PPARδ/p38 pathway

The mechanisms of WNT/β-catenin signaling involved in airway inflammation of chronic obstructive pulmonary disease (COPD) remain unknown, although recent observations have suggested an important contribution of the pathway in pulmonary parenchymal tissue repair and airway epithelium differentiation. We investigated the role of WNT/β-catenin signaling in cigarette smoke (CS)-related airway inflammation using patient lung tissues, human bronchial epithelial cells (16HBECs), and mouse models. Reduced activity of WNT/β-catenin signaling was observed in the airway epithelium of smokers with or without COPD. The mRNA expression of WNT transcription factor TCF4 negatively correlated with the pack year. The mRNA levels of WNT receptor FZD4 negatively correlated with the mRNA levels of IL-1β. CS exposure decreased the activity of WNT/β-catenin signaling in both 16HBECs and mice. In vitro studies demonstrated the upregulation of inflammatory cytokines TNF-α and IL-1β secretion induced by CS extract (CSE) could be attenuated by β-catenin activator SB216763 and be exacerbated by β-catenin small-interfering RNA (siRNA), respectively. Furthermore, the decrease in the expression of peroxisome proliferator-activated receptor (PPARδ) induced by CSE stimulation could be rescued by SB216763. SB216763 also attenuated the upregulation of phosphorylated p38 mitogen-activated protein kinase (MAPK) stimulated by CSE. Both PPARδ agonist and p38 MAPK inhibitor could suppress the TNF-α and IL-1β release induced by CSE treatment. In addition, PPARδ activation could abolish β-catenin siRNA-mediated aggravation of phosphorylated p38 MAPK in response to CSE. Finally, SB216763 treatment significantly ameliorated peribronchial inflammatory cell infiltration, leukocyte influx, and the release of TNF-α and IL-1β in the bronchoalveolar lavage fluid of CS-exposed mice. Taken together, our findings indicate that the reduced activity of WNT/β-catenin signaling induced by CS may promote inflammatory cytokine production in airway epithelium and have an essential role in airway inflammation in COPD by PPARδ/p38 MAPK pathway.

High Expression of Cathepsin E is Associated with the Severity of Airflow Limitation in Patients with COPD

BACKGROUND

It was reported that Cathepsin E (Cat E) plays a critical role in antigen processing and in the development of pulmonary emphysema. The aim of this study was to investigate the role of Cat E and airflow limitation in the pathogenesis of COPD.

METHODS

Sixty-five patients with COPD, 20 smoking control subjects without COPD and 15 non-smoking healthy control subjects were enrolled. Cat E and EIC (Elastase inhibitory capacity) expressions were measured by ELISA in sputum and serum samples and compared according to different subgroups.

RESULTS

Cat E concentrations were significantly higher in patients with COPD than smoking control and non-smoking control subjects (P < 0.01). The levels of CatE were inversely correlated with FEV1% predicted in COPD patients (r = -0.95, P < 0.01). The levels of EIC were inversely positively correlated with FEV1% predicted in COPD patients (r = 0.926, P < 0.01). Levels of Cat E were also inversely correlated with the levels of EIC (r = -0.922, P < 0.01).

CONCLUSIONS

Cat E contributes to the severity of airflow limitation during progression of COPD.

Utility of the CAT in the therapy assessment of COPD exacerbations in China

BACKGROUND

Chronic obstructive pulmonary disease (COPD) exacerbations are accompanied with increased systemic inflammation, which accelerate the pulmonary function injury and impair the quality of life. Prompt and effective treatments for COPD exacerbations slow down the disease progression, but an objective instrument to assess the efficacy of the treatments following COPD exacerbations is lacking nowadays. The COPD Assessment Test (CAT) is an 8-item questionnaire designed to assess and quantify health status and symptom burden in COPD patients. We hypothesize that the change in CAT score is related to the treatment response following COPD exacerbations.

METHODS

78 inpatients with clinician-diagnosed acute exacerbation of COPD (AECOPD) completed the CAT, St George's Respiratory Questionnaire (SGRQ) and modified Medical Research Council (mMRC) Dyspnea Scale both at exacerbation and the 7th day of therapy, and a subgroup of 39 patients performed the pulmonary function test. Concentrations of serum C-reactive protein (CRP) and plasma fibrinogen were assayed at the same time. Correlations between the CAT and other measurements were examined.

RESULTS

After 7 days' therapy, the CAT and SGRQ scores, mMRC grades, as well as the concentrations of CRP and fibrinogen all decreased significantly (P < 0.001). Meanwhile, the FEV1% predicted had a significant improvement (P < 0.001). The CAT scores were significantly correlated with concurrent concentrations of CRP and fibrinogen, SGRQ scores, FEV1% predicted and mMRC grades (P < 0.05). The change in CAT score was positively correlated with the change of CRP (r = 0.286, P < 0.05), SGRQ score (r = 0.725, P < 0.001) and mMRC grades (r = 0.593, P < 0.001), but not with fibrinogen (r = 0.137, P > 0.05) or FEV1% predicted (r = -0.101, P > 0.05). No relationship was found between the changes of SGRQ score and CRP and fibrinogen (P>0.05).

CONCLUSIONS

The CAT is associate with the changes of systemic inflammation following COPD exacerbations. Moreover, the CAT is responsive to the treatments, similar to other measures such as SGRQ, mMRC dyspnea scale and pulmonary function. Therefore, the CAT is a potentially useful instrument to assess the efficacy of treatments following COPD exacerbations.

Role of IL-18 in second-hand smoke-induced emphysema

Chronic second-hand smoke (SHS) exposure comprises the main risk factor for nonsmokers to develop chronic obstructive pulmonary disease (COPD). However, the mechanisms behind the chronic inflammation and lung destruction remain incompletely understood. In this study, we show that chronic exposure of Sprague-Dawley rats to SHS results in a significant increase of proinflammatory cytokine IL-18 and chemokine (C-C motif) ligand 5 in the bronchoalveolar lavage fluid (BALF) and a significant decrease of vascular endothelial growth factor (VEGF) in the lung tissue. SHS exposure resulted in progressive alveolar airspace enlargement, cell death, pulmonary vessel loss, vessel muscularization, collagen deposition, and right ventricular hypertrophy. Alveolar macrophages displayed a foamy phenotype and a decreased expression of the natural inhibitor of IL-18, namely, IL-18 binding protein (IL-18BP). Moreover, IL-18 down-regulated the expression of VEGF receptor-1 and VEGFR receptor-2, and induced apoptosis in pulmonary microvascular endothelial cells in vitro. We also observed a trend toward increased concentrations of IL-18 in the BALF of patients with COPD. Our findings suggest that IL-18-mediated endothelial cell death may contribute to vascular destruction and disappearance in SHS-induced COPD. Moreover, IL-18 and IL-18BP are potential new targets for therapeutics.

The Novartis view on emerging drugs and novel targets for the treatment of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a debilitating lung disease characterized by airflow limitation and chronic inflammation in the lungs. The mainstay of drug therapy for COPD is represented by long-acting bronchodilators, an important aspect of Novartis' development program. Novel once-daily dosing bronchodilators, such as the long-acting muscarinic antagonist (LAMA) glycopyrronium and the LAMA/long-acting β2-agonist (LABA) fixed-dose combination QVA149, have been shown to provide significant benefits to patients with COPD in terms of improvement in lung function, exercise tolerance, health-related quality of life, symptoms and reduction in the rate of exacerbations. Despite the benefits provided by these new treatment options, prevention of disease progression and control of exacerbations in certain patient phenotypes remain key challenges in the treatment of COPD. In order to address these needs and gain new insights into the complexity of COPD, Novartis is, in addition to bronchodilator-only therapies, developing LABA/inhaled corticosteroids (ICS) combinations to target inflammation, such as QMF149, as well as non-steroid based anti-inflammatory agents against key novel targets. These commitments are central to the Novartis' final goal of improving the standard of care in respiratory medicine and offering a better quality of life to patients with COPD.

Association of SELE genotypes/haplotypes with sE-selectin levels in Taiwanese individuals: interactive effect of MMP9 level

Background

E-selectin is implicated in various inflammatory processes and related disorders. We aimed to investigate the role of SELE-gene genotypes/haplotypes on plasma levels of MMP9 and sE-selectin in Taiwanese individuals.

Methods

Five hundred twenty individuals were enrolled. Seven tagging SELE single nucleotide polymorphisms were analyzed.

Results

SELE genotypes were found associated with MMP9 and sE-selectin levels. Multivariate analysis identified that the most significant genetic polymorphism (rs5368 genotype) was independently associated with MMP9 levels (P < 0.001). One haplotype (GGAGAGT) was marginally associated with MMP9 levels (P = 0.0490). One SELE SNP, (rs3917406, P = 0.031) was associated with sE-selectin levels after adjusting for MMP9 and sICAM1 levels. Subgroup and interaction analysis revealed association of SELE SNP rs10800469 with sE-selectin levels only in the highest quartile of MMP9 level (P = 0.002, interaction P = 0.023). Haplotype analysis showed one haplotype (AAAAAGC) borderline associated with sE-selectin level (P = 0.0511).

Conclusion

SELE genotypes/haplotypes are independently associated with MMP9 and E-selectin levels in Taiwanese individuals. The associations of SELE genotypes/haplotypes with sE-selectin levels are affected by MMP9 levels.

Determination of Ameliorable Health Impairment Influencing Health-Related Quality of Life among Patients with Silicosis in China: A Cross-Sectional Study

The association between health-related quality of life (HRQOL) and ameliorable health impairment was examined in 208 Chinese in-patients with silicosis, in April 2010. Median St George's Respiratory Questionnaire scores for symptom and activity impairment, social support rating scale and geriatric depression scale scores for patients were 57.24, 59.45, 35 and 5, respectively. Median 36-item short-form health survey physical component (PCS) and mental component (MCS) scores were 47.17 and 51.05, respectively. Lower than median PCS scores (< 47) were significantly associated with high levels of symptom and activity impairment. Lower than median MCS scores (< 51) were significantly associated with high levels of depression and activity impairment. Encouraging patients to participate in daily activities may alleviate activity impairment. Reasonable financial compensation may help to maintain and improve social support levels.

Sputum neutrophils as a biomarker in COPD: findings from the ECLIPSE study

INTRODUCTION

The percentage of neutrophils in sputum are increased in COPD patients, and may therefore be a biomarker of airway inflammation. We studied the relationships between sputum neutrophils and FEV1, health status, exacerbation rates, systemic inflammation and emphysema, and long term variability at 1 year.

METHODS

Sputum samples were obtained from 488 COPD patients within the ECLIPSE cohort. 359 samples were obtained at baseline, and 297 after 1 year. 168 subjects provided samples at both visits. Serum interleukin-6 (IL-6), IL-8, surfactant protein D and C-reactive protein levels were measured by immunoassays. Low-dose CT scans evaluated emphysema.

RESULTS

Sputum neutrophil % increased with GOLD stage. There was a weak association between % sputum neutrophils and FEV1 % predicted (univariate r2 = 0.025 and 0.094 at baseline and year 1 respectively, p < 0.05 after multivariate regression). Similar weak but significant associations were observed between neutrophil % and health status measured using the St Georges Respiratory Questionairre. There were no associations between neutrophils and exacerbation rates or emphysema. Associations between sputum neutrophils and systemic biomarkers were non-significant or similarly weak. The mean change over 1 year in neutrophil % was an increase of 3.5%.

CONCLUSIONS

Sputum neutrophil measurements in COPD are associated weakly with FEV1 % predicted and health status. Sputum neutrophil measurements were dissociated from exacerbation rates, emphysema and systemic inflammation.

Local inflammation occurs before systemic inflammation in patients with COPD

BACKGROUND AND OBJECTIVE

COPD is associated not only with an abnormal inflammatory response in the lung but also with systemic inflammation, including systemic oxidative stress, activation of circulating inflammatory cells and increased circulating levels of inflammatory cytokines. Understanding the nature and course of systemic inflammation in COPD is important given the potential for anti-inflammatory therapy. This study explored whether local and systemic inflammation occur concurrently in patients with COPD.

METHODS

Forty-four patients with stable COPD, 10 smoking controls and 10 non-smoking controls were enrolled in this observational study. Induced sputum and peripheral blood samples were obtained simultaneously for measurement of inflammatory cell numbers and the concentrations of IL-6 and CRP.

RESULTS

The total number of cells in the sputum total cell number, percentage of neutrophils and the concentration of IL-6 were significantly higher in smoking controls and patients with COPD than in non-smoking controls (P < 0.05 and P < 0.01, respectively). As the disease stage progressed, airway inflammatory cells and IL-6 levels increased. CRP levels in sputum were significantly higher in stage II, III and IV COPD patients than in smoking and non-smoking controls (P < 0.01). However, the peripheral WCC and percentage of neutrophils were similar in patients with COPD, smoking and non-smoking controls. Circulatory concentrations of IL-6 and CRP in stages III and IV COPD patients were significantly higher than in smoking and non-smoking controls (P < 0.05 and P < 0.01, respectively). Additionally, there were positive correlations between sputum and blood IL-6 and CRP levels (r = 0.566, P < 0.01 and r = 0.443, P < 0.01, respectively).

CONCLUSIONS

The increase in the inflammatory cell population and IL-6 and CRP levels in the airway may occur earlier than in the peripheral blood, and reflect the degree of airflow limitation better than do peripheral blood measurements. Systemic inflammation may be present in patients with severe or very severe COPD.

Progression of chronic obstructive pulmonary disease: impact of inflammation, comorbidities and therapeutic intervention

BACKGROUND AND AIM

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality, and through under-diagnosis, is often inappropriately treated. This multicomponent disease involves both airway and systemic inflammation at all stages and may influence the progression of disease and the pathophysiology of comorbidities. This review examines evidence linking inflammation, disease progression and comorbidities in COPD, and the potential role of anti-inflammatory therapies.

METHODS

Systematic searches of Medline and Cochrane Reviews databases from 1976 to March 2008 using the terms: chronic obstructive pulmonary disease, disease progression, inflammation, inflammatory, comorbid condition, comorbidity, treatment, therapy, bronchodilator, inhaled corticosteroid.

FINDINGS

Increased levels of interleukin-8, tumour necrosis factor-alpha and systemic C-reactive protein correlate with worse disease severity, exacerbation rates and lung function decline. Increased systemic C-reactive protein is also associated with poorer health status and comorbidities (e.g. cardiovascular disease, cancer and skeletal muscle dysfunction). The pivotal role of inflammation in the pathogenesis of COPD and its comorbidities suggests anti-inflammatory therapies will be important in the overall management of COPD. Long-term studies indicate that combination therapies consisting of a long-acting beta-agonist plus an inhaled corticosteroid in one inhaler have the potential to modify disease progression through positive effects on lung function, exacerbations, symptoms and health status. The TOwards a Revolution in COPD Health (TORCH) study is the first to demonstrate that a COPD pharmacotherapy (combination salmeterol plus fluticasone propionate) significantly decreased the rate of lung function decline versus placebo.

CONCLUSION

Better understanding of the specific inflammatory mechanisms underlying COPD disease progression and associated comorbidities will likely lead to more effective management of the disease.

The relation of genetic and environmental factors to systemic inflammatory biomarker concentrations

BACKGROUND

Environmental and genetic correlates of inflammatory marker variability are incompletely understood. In the family-based Framingham Heart Study, we investigated heritability and candidate gene associations of systemic inflammatory biomarkers.

METHODS AND RESULTS

In offspring participants (n=3710), we examined 11 inflammatory biomarkers (CD40 ligand, C-reactive protein, intercellular adhesion molecule-1, interleukin-6, urinary isoprostanes, monocyte chemoattractant protein-1, myeloperoxidase, P-selectin, tumor necrosis factor-alpha, tumor necrosis factor receptor II, fibrinogen). Heritability and bivariate genetic and environmental correlations were assessed by Sequential Oligogenic Linkage Analysis routines in 1012 family members. We examined 1943 tagging single-nucleotide polymorphisms in 233 inflammatory pathway genes with >or=5 minor allele carriers using a general genetic linear model. Clinical correlates explained 2.4% (CD40 ligand) to 28.5% (C-reactive protein) of the variability in inflammatory biomarkers. Estimated heritability ranged from 10.9% (isoprostanes) to 44.8% (P-selectin). Most correlations between biomarkers were weak although statistically significant. A total of 45 single-nucleotide polymorphism-biomarker associations met the q-value threshold of 0.25. Novel top single-nucleotide polymorphisms were observed in ICAM1 gene in relation to intercellular adhesion molecule-1 concentrations (rs1799969, P=1.32 x 10(-8)) and MPO in relation to myeloperoxidase (rs28730837, P=1.9 x 10(-5)). Lowest P values for trans-acting single-nucleotide polymorphisms were observed for APCS with monocyte chemoattractant protein-1 concentrations (rs1374486, P=1.01 x 10(-7)) and confirmed for IL6R with interleukin-6 concentrations (rs8192284, P=3.36 x 10(-5)). Novel potential candidates (APCS, MPO) need to be replicated.

CONCLUSIONS

Our community-based data support the relevance of clinical and genetic factors for explaining variation in inflammatory biomarker traits.

Enhanced levels of prostaglandin E2 and matrix metalloproteinase-2 correlate with the severity of airflow limitation in stable COPD

BACKGROUND AND OBJECTIVE

Cyclooxygenase-2 (COX-2) and its product prostaglandin E2 (PGE2) have been demonstrated to play critical roles in inflammation in respiratory diseases. However, the role of COX-2 in airway remodelling in COPD remains to be elucidated. Matrix metalloproteinase-2 (MMP-2) is associated with both inflammation and airway remodelling in COPD. The objective of this study was to measure the expression of COX-2 and the concentrations of PGE2 and MMP-2, and to investigate the role of COX-2 and PGE2 in airflow limitation mediated by MMP-2, in the pathogenesis of COPD.

METHODS

Forty-three patients with stable COPD, twelve smoking control subjects and ten nonsmoking control subjects were enrolled. Induced sputum was obtained for measurement of the concentrations of PGE2 and MMP-2 by ELISA. COX-2 protein expression was assessed by western blotting.

RESULTS

PGE2 and MMP-2 concentrations were significantly higher in both smoking control subjects and patients with COPD than in non-smoking control subjects (P < 0.01).Moreover, the levels of PGE2 andMMP-2 were inversely correlated with FEV1%predicted in COPD patients (PGE2: r = -0.748, P < 0.01; MMP-2: r = -0.801, P < 0.01). Levels of PGE2 were also positively correlated with those of MMP-2 in patients with COPD (r = 0.775, P < 0.01). Expression of COX-2 protein was significantly higher in COPD patients than in non-smoking control subjects.

CONCLUSIONS

COX-2 and its product PGE2 are not only involved in airway inflammation, but may also contribute to the severity of airflow limitation mediated by MMP-2 during progression of COPD.

Extra-pulmonary features in COPD patients entering rehabilitation after stratification for MRC dyspnea grade

Experts have stated that referral for rehabilitation of patients with chronic obstructive pulmonary disease (COPD) becomes appropriate when these patients become aware of their disability (e.g. usually grade 3 to 5 on the Medical Research Council (MRC) dyspnea scale). However, patients with MRC dyspnea grade 1/2 may also suffer from extra-pulmonary features, such as abnormal body composition, exercise intolerance and reduced disease-specific health status. In the present study, we have studied whether and to what extent chronic obstructive pulmonary disease (COPD) patients with MRC dyspnea grade 1/2 have extra-pulmonary features compared to patients with grade 3, 4 or 5? Pulmonary function, body composition, 6-min walking distance, peak exercise capacity, anxiety, depression and disease-specific health status have been assessed in 333 outpatients who had been referred for pulmonary rehabilitation. On average, patients with MRC dyspnea grade 1/2 had a better exercise tolerance and disease-specific health status compared to patients with grade 4 or 5. Nevertheless, grade 1/2 patients had a higher prevalence of muscle mass depletion. In addition, these patients did still have aberrant values in one or more of the aforementioned outcomes. On average, patients with MRC dyspnea grade 1/2 may clearly suffer from extra-pulmonary features, indicating the necessity to refer these patients for rehabilitation. Therefore, MRC dyspnea scale alone does not appear to be a suitable measure to identify most patients with COPD who have to be referred for rehabilitation.