Biomarkers of systemic inflammation in stable and exacerbation phases of COPD

Shengmai Powder regulates alveolar macrophage PPAR-γ and improves the chronic inflammatory state of chronic obstructive pulmonary disease

This study examines the therapeutic effects of Shengmai Powder (SMP) on both in vitro and in vivo models of chronic obstructive pulmonary disease (COPD) and the underlying mechanisms. Cigarette smoke and cigarette extracts were used to create in vitro and in vivo models of COPD. ELISA was used to measure the levels of pro-inflammatory factors (IL-6, TNF-α, and IL-1β) in mouse lung tissue and alveolar macrophages. Flow cytometry assessed the phagocytic capacity of alveolar macrophage. Western blotting was used to analyze the expression of RhoA, PPARγ, IκBα, p-IκBα, P65, and p-P65 in alveolar. The results show that SMP reversed the increased levels of pro-inflammatory factors (IL-6, TNF-α, and IL-1β) in mouse lung tissue and alveolar macrophages induced by cigarette smoke and cigarette extract. SMP also restored the decreased fluorescence intensity and RhoA levels in alveolar macrophages caused by cigarette extract. Additionally, SMP increased PPARγ expression and decreased IκBα and P65 phosphorylation in alveolar macrophages exposed to cigarette extract. Also, the effects of SMP were reversed by PPARγ inhibitors. The study concluded that SMP regulates alveolar macrophage phagocytic function through the PPAR-γ/NF-κB pathway, thereby improving the chronic inflammatory state of COPD.

Botanical formulation HX110B ameliorates PPE-induced emphysema in mice via regulation of PPAR/RXR signaling pathway

Chronic obstructive pulmonary disease (COPD), an inflammatory lung disease, causes approximately 3 million deaths each year; however, its pathological mechanisms are not fully understood. In this study, we examined whether HX110B, a mixture of Taraxacum officinale, Dioscorea batatas, and Schizonepeta tenuifolia extracts, could suppress porcine pancreatic elastase (PPE)-induced emphysema in mice and its mechanism of action. The therapeutic efficacy of HX110B was tested using a PPE-induced emphysema mouse model and human bronchial epithelial cell line BEAS-2B. In vivo data showed that the alveolar wall and air space expansion damaged by PPE were improved by HX110B administration. HX110B also effectively suppresses the expression levels of pro-inflammatory mediators including IL-6, IL-1β, MIP-2, and iNOS, while stimulating the expression of lung protective factors such as IL-10, CC16, SP-D, and sRAGE. Moreover, HX110B improved the impaired OXPHOS subunit gene expression. In vitro analysis revealed that HX110B exerted its effects by activating the PPAR-RXR signaling pathways. Overall, our data demonstrated that HX110B could be a promising therapeutic option for COPD treatment.

The pomegranate-derived peptide Pug-4 alleviates nontypeable Haemophilus influenzae-induced inflammation by suppressing NF-kB signaling and NLRP3 inflammasome activation

The respiratory pathogen nontypeable Haemophilus influenzae (NTHi) is the most common cause of exacerbation of chronic obstructive pulmonary disease (COPD), of which an excessive inflammatory response is a hallmark. With the limited success of current medicines there is an urgent need for the development of novel therapeutics that are both safe and effective. In this study, we explored the regulatory potential of pomegranate-derived peptides Pug-1, Pug-2, Pug-3, and Pug-4 on NTHi-induced inflammation. Our results clearly showed that to varying degrees the Pug peptides inhibited NTHi-induced production of IL-1β, a pivotal cytokine in COPD, and showed that these effects were not related to cytotoxicity. Pug-4 peptide exhibited the most potent inhibitory activity. This was demonstrated in all studied cell types including murine (RAW264.7) and human (differentiated THP-1) macrophages as well as human lung epithelial cells (A549). Substantial reduction by Pug-4 of TNF-α, NO and PGE2 in NTHi-infected A549 cells was also observed. In addition, Pug-4 strongly inhibited the expression of nuclear-NF-κB p65 protein and the NF-κB target genes (determined by IL-1β, TNF-α, iNOS and COX-2 mRNA expression) in NTHi-infected A549 cells. Pug-4 suppressed the expression of NLRP3 and pro-IL-1β proteins and inhibited NTHi-mediated cleavage of caspase-1 and mature IL-1β. These results demonstrated that Pug-4 inhibited NTHi-induced inflammation through the NF-κB signaling and NLRP3 inflammasome activation. Our findings herein highlight the significant anti-inflammatory activity of Pug-4, a newly identified peptide from pomegranate, against NTHi-induced inflammation. We therefore strongly suggest the potential of the Pug-4 peptide as an anti-inflammatory medicine candidate for treatment of NTHi-mediated inflammation.

The Molecular Blueprint for Chronic Obstructive Pulmonary Disease (COPD): A New Paradigm for Diagnosis and Therapeutics

The global prevalence of chronic obstructive pulmonary disease (COPD) has increased over the last decade and has emerged as the third leading cause of death worldwide. It is characterized by emphysema with prolonged airflow limitation. COPD patients are more susceptible to COVID-19 and increase the disease severity about four times. The most used drugs to treat it show numerous side effects, including immune suppression and infection. This review discusses a narrative opinion and critical review of COPD. We present different aspects of the disease, from cellular and inflammatory responses to cigarette smoking in COPD and signaling pathways. In addition, we highlighted various risk factors for developing COPD apart from smoking, like occupational exposure, pollutants, genetic factors, gender, etc. After the recent elucidation of the underlying inflammatory signaling pathways in COPD, new molecular targeted drug candidates for COPD are signal-transmitting substances. We further summarize recent developments in biomarker discovery for COPD and its implications for disease diagnosis. In addition, we discuss novel drug targets for COPD that could be explored for drug development and subsequent clinical management of cardiovascular disease and COVID-19, commonly associated with COPD. Our extensive analysis of COPD cause, etiology, diagnosis, and therapeutic will provide a better understanding of the disease and the development of effective therapeutic options. In-depth knowledge of the underlying mechanism will offer deeper insights into identifying novel molecular targets for developing potent therapeutics and biomarkers of disease diagnosis.

Omega-3 Polyunsaturated Fatty Acids in Managing Comorbid Mood Disorders in Chronic Obstructive Pulmonary Disease (COPD): A Review

Chronic obstructive pulmonary disease (COPD) is the third-leading cause of mortality globally, significantly affecting people over 40 years old. COPD is often comorbid with mood disorders; however, they are frequently neglected or undiagnosed in COPD management, thus resulting in unintended treatment outcomes and higher mortality associated with the disease. Although the exact link between COPD and mood disorders remains to be ascertained, there is a broader opinion that inflammatory reactions in the lungs, blood, and inflammation-induced changes in the brain could orchestrate the onset of mood disorders in COPD. Although the current management of mood disorders such as depression in COPD involves using antidepressants, their use has been limited due to tolerability issues. On the other hand, as omega-3 polyunsaturated fatty acids (n-3 PUFAs) play a vital role in regulating inflammatory responses, they could be promising alternatives in managing mood disorders in COPD. This review discusses comorbid mood disorders in COPD as well as their influence on the progression and management of COPD. The underlying mechanisms of comorbid mood disorders in COPD will also be discussed, along with the potential role of n-3 PUFAs in managing these conditions.

Effect of Smoking and Its Cessation on the Transcript Profile of Peripheral Monocytes in COPD Patients

Rationale

Smoking is the primary cause of chronic obstructive pulmonary disease (COPD); however, only 10–20% of smokers develop the disease suggesting possible genomic association in the causation of the disease. In the present study, we aimed to explore the whole genome transcriptomics of blood monocytes from COPD smokers (COPD-S), COPD Ex-smokers (COPD-ExS), Control smokers (CS), and Control Never-smokers (CNS) to understand the differential effects of smoking, COPD and that of smoking cessation.

Methods

Exploratory analyses in form of principal component analysis (PCA) and hierarchical component analysis (uHCA) were performed to evaluate the similarity in gene expression patterns, while differential expression analyses of different supervised groups of smokers and never smokers were performed to study the differential effect of smoking, COPD and smoking cessation. Differentially expressed genes among groups were subjected to post-hoc enrichment analysis. Candidate genes were subjected to external validation by quantitative RT-PCR experiments.

Results

CNS made a cluster completely segregated from the other three subgroups (CS, COPDS and COPD-ExS). About 550, 8 and 5 genes showed differential expression, respectively, between CNS and CS, between CS and COPD-S, and between COPD-S and COPD-ExS. Apoptosis, immune response, cell adhesion, and inflammation were the top process networks identified in enrichment analysis. Two candidate genes (CASP9 and TNFRSF1A) found to be integral to several pathways in enrichment analysis were validated in an external validation experiment.

Conclusion

Control never smokers had formed a cluster distinctively separated from all smokers (COPDS, COPD-ExS, and CS), while amongst all smokers, control smokers had aggregated in a separate cluster. Smoking cessation appeared beneficial if started at an early stage as many genes altered due to smoking started reverting towards the baseline, whereas only a few COPD-related genes showed reversal after smoking cessation.

Hypercoagulation in COPD: the clot thickens

There is a growing body of evidence that hypercoagulability is present in stable COPD, involves changes in multiple coagulation factors, and is not simply associated with major causes of inflammation and thrombosis https://bit.ly/3F5NnfN.

Elevated levels of arginase activity are related to inflammation in patients with COPD exacerbation

Introduction

Within the pathogenesis of the chronic obstructive pulmonary disease (COPD) there are interactions between different inflammatory mediators that are enhanced during an exacerbation. Arginase is present in bronchial epithelial cells, endothelial, fibroblasts and alveolar macrophages, which make it a probable key enzyme in the regulation of inflammation and remodelling. We aimed to find a potential relationship between arginase activity, inflammatory mediators in COPD patients in stable phase and during exacerbations.

Methods

We performed a prospective, observational study of cases and controls, with 4 study groups (healthy controls, stable COPD, COPD during an exacerbation and COPD 3 months after exacerbation). We measured arginase, inflammation markers (IL-6, IL-8, TNF-∝, IFN-γ and C reactive protein), and mediators of immunity: neutrophils, monocytes, total TCD3 + lymphocytes (CD3ζ), CD4 + T cells, CD8 + T cells, NK cells.

Results

A total of 49 subjects were recruited, average age of 69.73 years (59.18% male). Arginase activity is elevated during an exacerbation of COPD, and this rise is related to an increase in IL-6 production. The levels of IL-6 and IL-8 remained elevated in patients with COPD at 3 months after hospital exacerbation.

We did not find a clear relationship between arginase activity, immunity or with the degree of obstruction in COPD patients.

Conclusions

Arginase activity is elevated during an exacerbation of COPD, and it could be related to an increase in the production of IL-6. Levels of IL-6, IL-8, and arginase activity remain elevated in patients with COPD at 3 months after hospital exacerbation. Arginase activity could contribute to the development of COPD.

Combination of Systemic Inflammatory Biomarkers in Assessment of Chronic Obstructive Pulmonary Disease: Diagnostic Performance and Identification of Networks and Clusters

Interleukin (IL)-1α, IL-1β, IL-6, IL-8 and tumor necrosis factor (TNF)α contribute to inflammation in chronic obstructive pulmonary disease (COPD). We wanted to investigate their interrelations and association with disease severity, as well as to combine them with other inflammation-associated biomarkers and evaluate their predictive value and potential in identifying various patterns of systemic inflammation. One hundred and nine patients with stable COPD and 95 age- and sex-matched controls were enrolled in the study. Cytokines’ concentrations were determined in plasma samples by antibody-based multiplex immunosorbent assay kits. Investigated cytokines were increased in COPD patients but were not associated with disease or symptoms severity. IL-1β, IL-6 and TNFα showed the best discriminative values regarding ongoing inflammation in COPD. Inflammatory patterns were observed in COPD patients when cytokines, C-reactive protein (CRP), fibrinogen (Fbg), extracellular adenosine triphosphate (eATP), extracellular heat shock protein 70 (eHsp70) and clinical data were included in cluster analysis. IL-1β, eATP and eHsp70 combined correctly classified 91% of cases. Therefore, due to the heterogeneity of COPD, its assessment could be improved by combination of biomarkers. Models including IL-1β, eATP and eHsp70 might identify COPD patients, while IL-1β, IL-6 and TNFα combined with CRP, Fbg, eATP and eHsp70 might be informative regarding various COPD clinical subgroups.

GTS-21, an α7nAChR agonist, suppressed the production of key inflammatory mediators by PBMCs that are elevated in COPD patients and associated with impaired lung function

Chronic obstructive pulmonary disease (COPD) is a lung inflammatory disease characterized by progressive airflow limitation, chronic respiratory symptoms and frequent exacerbations. There is an unmet need to identify novel therapeutic alternatives beside bronchodilators that prevent disease progression. Levels of both Nitric Oxide (NO) and IL-6 were significantly increased in the plasma of patients in the exacerbation phase (ECOPD, n = 13) when compared to patients in the stable phase (SCOPD, n = 38). Levels of both NO and IL-6 were also found to inversely correlate with impaired lung function (%FEV1 predicted). In addition, there was a strong positive correlation between levels of IL-6 and NO found in the plasma of patients and those spontaneously produced by their peripheral blood mononuclear cells (PBMCs), identifying these cells as a major source of these key inflammatory mediators in COPD. GTS-21, an agonist for the alpha 7 nicotinic receptors (α7nAChR), was found to exert immune-modulatory actions in PBMCs of COPD patients by suppressing the production of IL-6 and NO. This study provides the first evidence supporting the therapeutic potential of α7nAChR agonists in COPD due to their ability to suppress the production of key inflammatory markers associated with disease severity.

Association between tumor necrosis factor-α and chronic obstructive pulmonary disease: a systematic review and meta-analysis

Background:

Patients diagnosed with chronic obstructive pulmonary disease (COPD) have increased risks for a series of physical and mental illnesses. Tumor necrosis factor-α (TNF-α) has been reported to participate in the development of COPD and its complications. However, the values of blood TNF-α level used in the diagnosis of COPD remains controversial. In view of this, we performed a systematic review and meta-analysis to evaluate the correlation between TNF-α level and COPD.

Methods:

We searched PubMed, Web of Science, Embase and CNKI up to May 2018. The selection criteria were set according to the PICOS framework. A random-effects model was then applied to evaluate the overall effect sizes by calculating standard mean difference (SMD) and its 95% confidence intervals (CIs).

Results:

A total of 40 articles containing 4189 COPD patients and 1676 healthy controls were included in this meta-analysis. The results indicated a significant increase in TNF-α level in the COPD group compared with the control group (SMD: 1.24, 95% CI: 0.78–1.71, p < 0.00001). According to the subgroup analyses, we noted that TNF-α level was associated with predicted first second of forced expiration (FEV₁) (%) and study region. However, no association between TNF-α level and COPD was found when the participants were nonsmokers, and the mean age was less than 60 years.

Conclusions:

Our results indicated that TNF-α level was increased in COPD patients when compared with healthy controls. Illness progression and a diagnosis of COPD might contribute to higher TNF-α levels. However, the underlying mechanism still remains unknown and needs further investigation.

The reviews of this paper are available via the supplemental material section.

Systemic biomarkers of inflammation, oxidative stress and tissue injury and repair among waterpipe, cigarette and dual tobacco smokers

BACKGROUND

Waterpipe tobacco (WPT) smoking is associated with deleterious effects on cardio-pulmonary systems which may have adverse repercussions in pathophysiology and progression of chronic lung and cardiovascular diseases. We compared the biomarkers of systemic inflammation, lipid mediators, injury/repair and oxidative stress between groups of non-smokers (NS), exclusive WPT smokers (WPS), exclusive cigarette smokers (CS) and dual WPS and CS (DS).

METHODS

Two cohorts were recruited. Cohort I consisted of WPS (n=12), CS (n=26), DS (n=10) and NS (n=25). Cohort II consisted of WPS (n=33) and NS (n=24). Plasma and urine samples were collected and analysed for various systemic biomarkers.

RESULTS

Compared with NS, plasma levels of inflammatory mediators (interleukin (IL)-6, IL-8, IL1β and tumor necrosis factor-α) were significantly higher in WPS and CS, and were further augmented in DS. Endothelial biomarkers (intracellular adhesion molecule-1, prostaglandin E-2 and metalloproteinase-9) were significantly higher in CS. Most notably, pro-resolving lipid mediator (resolvin E1) and biomarkers of immunity, tissue injury, and repair were significantly lower in WPS and CS. Urinary levels of 8-isoprostane were significantly higher in all smoking groups in cohort I, while 8-isoprostane, myeloperoxidase, receptor for advanced glycation end products (RAGE), En-RAGE and matrix metalloproteinase-9 were significantly higher in all smoking groups in cohort II.

CONCLUSIONS

Biomarkers of inflammation, oxidative stress, immunity, tissue injury and repair were elevated in WPS and CS groups. Furthermore, concurrent use of WPT and cigarettes is more harmful than cigarette or WPT smoking alone. These data may help inform the public and policy-makers about the dangers of WPT smoking and dual use of tobacco products.

Electrochemical methods for detection of biomarkers of Chronic Obstructive Pulmonary Disease in serum and saliva

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death nowadays, and its underdiagnosis is still a great challenge. More effective diagnosis method is in urgent need since the traditional spirometry has many limitations in the practical application. The electrochemical (EC) detection methods have their unique advantages of high accuracy, short response time and easy integration of the system. In this review, recent works on the EC methods for COPD biomarkers including interleukin 6 (IL-6), interleukin 8 (IL-8) and C-reactive protein (CRP) are summarized. Five types of EC methods are highlighted in this study, as enzyme-labelled immunosensors, nanoparticle-labelled immunosensors, capacitive or impedimetric immunosensors, magnetoimmunosensors, and field effect transistor (FET) immunosensors. To date, EC immunosensors have been exhibiting high analytical performance with a detection limit that can achieve several pg/mL or even lower. The simplicity of EC immunosensors makes them a perfect solution for a future point-of-care device to use in settings for COPD diagnosis and follow-up. Nevertheless, more efforts need to be paid on the simultaneous detection of multiple biomarkers, a demand for the clinical diagnosis, and processes of assay simplification towards achieving one-step detection.

Inference of Cellular Immune Environments in Sputum and Peripheral Blood Associated with Acute Exacerbations of COPD

Introduction

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death in the United States, with high associated costs. Most of the cost burden results from acute exacerbations of COPD (AE-COPD), events associated with heightened symptoms and mortality. Cellular mechanisms underlying AE-COPD are poorly understood, likely because they arise from dysregulation of complex immune networks across multiple tissue compartments.

Methods

To gain systems-level insight into cellular environments relevant to exacerbation, we applied data-driven modeling approaches to measurements of immune factors (cytokines and flow cytometry) measured previously in two different human tissue environments (sputum and peripheral blood) during the stable and exacerbated state.

Results

Using partial least squares discriminant analysis, we identified a unique signature of cytokines in serum that differentiated stable and AE-COPD better than individual measurements. Furthermore, we found that models integrating data across tissue compartments (serum and sputum) trended towards being more accurate. The resulting paracrine signature defining AE-COPD events combined elevations of proteins associated with cell adhesion (sVCAM-1, sICAM-1) and increased levels of neutrophils and dendritic cells in blood with elevated chemoattractants (IP-10 and MCP-2) in sputum.

Conclusions

Our results supported a new hypothesis that AE-COPD is driven by immune cell trafficking into the lung, which requires expression of cell adhesion molecules and raised levels of innate immune cells in blood, with parallel upregulated expression of specific chemokines in pulmonary tissue. Overall, this work serves as a proof-of-concept for using data-driven modeling approaches to generate new insights into cellular processes involved in complex pulmonary diseases.

Frailty assessment in older adults with chronic obstructive respiratory diseases

The number of patients with chronic obstructive pulmonary disease (COPD) has been rising with continued exposure to environmental risk factors and aging of populations around the world. Frailty is a geriatric syndrome with a decline in physiological reserve and often coexists with chronic diseases such as COPD. Frailty is an independent risk factor for the development and progression of COPD, and COPD can lead to frailty; treating one might improve the other. Thus, there is an increasing interest in the assessment of frailty in patients with COPD. Furthermore, early identification and assessment of frailty in patients with COPD may affect the choice of intervention and improve its effectiveness. Based on the current literature, the intent of this review was to summarize and discuss frailty assessment tools used for COPD patients and the relevant clinical practices for predicting outcomes. We ascertain that using suitable frailty assessment tools could facilitate physicians to screen and stratify physically frail patients with COPD. Screening appropriately targeted population can achieve better intervention outcomes and pulmonary rehabilitation among frail COPD patients.

Frailty in the End-Stage Lung Disease or Heart Failure Patient: Implications for the Perioperative Transplant Clinician

The syndrome of frailty for patients undergoing heart or lung transplantation has been a recent focus for perioperative clinicians because of its association with postoperative complications and poor outcomes. Patients with end-stage cardiac or pulmonary failure may be under consideration for heart or lung transplantation along with bridging therapies such as ventricular assist device implantation or venovenous extracorporeal membrane oxygenation, respectively. Early identification of frail patients in an attempt to modify the risk of postoperative morbidity and mortality has become an important area of study over the last decade. Many quantification tools and risk prediction models for frailty have been developed but have not been evaluated extensively or standardized in the cardiothoracic transplant candidate population. Heightened awareness of frailty, coupled with a better understanding of distinct cellular mechanisms and biomarkers apart from end-stage organ disease, may play an important role in potentially reversing frailty related to organ failure. Furthermore, the clinical management of these critically ill patients may be enhanced by waitlist and postoperative physical rehabilitation and nutritional optimization.

The pulmonary rehabilitation regimen: a treatment for frailty and 'inflammaging'?

Pulmonary rehabilitation is an exercise-based intervention that improves walking endurance, strength, functional independence, wellbeing and the risk of re-admission to hospital. It was developed for patients recovering from acute exacerbations of chronic obstructive pulmonary disease, and sometimes other long-term inflammatory lung diseases. Many other conditions have a chronic inflammatory component, including type 2 diabetes, obesity, osteoarthritis and old age. Such background inflammation is linked to a range of adverse outcomes, including all-cause mortality, sarcopenia and other markers of frailty. Exercise, including pulmonary rehabilitation, has an anti-inflammatory effect on innate immune chemistry, and improves outcomes in a variety of conditions, although for most diagnostic groups there is no consistent structured programme similar to pulmonary rehabilitation. The authors contend that the pulmonary rehabilitation model could be used generically to treat other chronic and post-acute inflammatory states and thereby reduce the risk of frailty and other adverse outcomes.

Antiplatelet therapy in the primary prevention of cardiovascular disease in patients with chronic obstructive pulmonary disease: protocol of a randomised controlled proof-of-concept trial (APPLE COPD-ICON 2)

INTRODUCTION

The antiplatelet therapy in the primary prevention of cardiovascular disease in patients with chronic obstructive pulmonary disease (APPLE COPD-ICON2) trial is a prospective 2×2 factorial, double-blinded proof-of-concept randomised controlled trial targeting patients with chronic obstructive pulmonary disease (COPD) at high risk of cardiovascular disease. The primary goal of this trial is to investigate if treatment with antiplatelet therapy will produce the required response in platelet function measured using the Multiplate test in patients with COPD.

METHODS AND ANALYSIS

Patients with COPD are screened for eligibility using inclusion and exclusion criteria. Eligible patients are randomised and allocated into one of four groups to receive aspirin plus placebo, ticagrelor plus placebo, aspirin plus ticagrelor or placebo only. Markers of systemic inflammation, platelet reactivity, arterial stiffness, carotid intima-media thickness (CIMT), lung function and quality of life questionnaires are assessed. The primary outcome consists of inhibition (binary response) of aspirin and ADP-induced platelet function at 6 months. Secondary outcomes include changes in inflammatory markers, CIMT, non-invasive measures of vascular stiffness, quality of life using questionnaires (EuroQol-five dimensions-five levels of perceived problems (EQ5D-5L), St. George's COPD questionnaire) and to record occurrence of repeat hospitalisation, angina, myocardial infarction or death from baseline to 6 months. Safety outcomes will be rates of major and minor bleeding, forced expiratory volume in 1 s, forced vital capacity and Medical Research Council dyspnoea scale.

ETHICS AND DISSEMINATION

The study was approved by the North East-Tyne and Wear South Research Ethics Committee (15/NE/0155). Findings of the study will be presented in scientific sessions and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ISRCTN43245574; Pre-results.

The systemic nature of mustard lung: Comparison with COPD patients

Sulphur mustard (SM) is a powerful blister-causing alkylating chemical warfare agent used by Iraqi forces against Iran. One of the known complications of mustard gas inhalation is mustard lung which is discussed as a phenotype of chronic obstructive pulmonary disease (COPD). In this complication, there are clinical symptoms close to COPD with common etiologies, such as in smokers. Based on information gradually obtained by conducting the studies on mustard lung patients, systemic symptoms along with pulmonary disorders have attracted the attention of researchers. Changes in serum levels of inflammatory markers, such as C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), nuclear factor κB (NF-κB), matrix metalloproteinases (MMPs), interleukin (IL), chemokines, selectins, immunoglobulins, and signs of imbalance in oxidant-antioxidant system at serum level, present the systemic changes in these patients. In addition to these, reports of extra-pulmonary complications, such as osteoporosis and cardiovascular disease are also presented. In this study, the chance of developing the systemic nature of this lung disease have been followed on using the comparative study of changes in the mentioned markers in mustard lung and COPD patients at stable phases and the mechanisms of pathogenesis and phenomena, such as airway remodeling in these patients.

An ECLIPSE View of Alpha-1 Antitrypsin Deficiency

Chronic obstructive pulmonary disease (COPD) is a multicomponent condition that is estimated to become the third leading cause of death in 2020. The ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints) study, funded by GlaxoSmithKline, is an observational study designed to define outcomes that can be used as endpoints in clinical trials in individuals with COPD. It allowed us to describe the heterogeneity of COPD, the stability of the exacerbation phenotype, and the factors associated with a progressive decline in lung function and the progression of emphysema on computed tomography scans. The cohort was also used to define genetic factors and biomarkers associated with COPD and disease progression. This review considers how the results from ECLIPSE can inform our understanding of the lung disease associated with alpha-1 antitrypsin deficiency.

Correlation between heart size and emphysema in patients with chronic obstructive pulmonary disease: CT-based analysis using inspiratory and expiratory scans

The objective of this study was to investigate the relationship between the extent of emphysema and heart size in patients with chronic obstructive pulmonary disease (COPD) using inspiratory and expiratory chest computed tomography (CT). This retrospective study was approved by the institutional review board and informed consent was waived. We measured lung volume (LV), low attenuation area percent (%LAA; less than or equal to −950 HU), maximum cardiac area, and maximum transverse cardiac diameter on inspiratory/expiratory chest CT in 60 patients with COPD. Spearman rank correlation analysis was used to determine the correlations between the heart and lung CT measurements, and the correlations between these measurements and spirometric values. On inspiratory CT, the maximum transverse cardiac diameter was negatively correlated with LV (ρ = −0.42; p < 0.01) and %LAA (ρ = −0.43; p < 0.001). Furthermore, on expiratory CT, the maximum cardiac area was negatively correlated with LV (ρ = −0.35; p < 0.01) and %LAA (ρ = −0.37; p < 0.01), and there was a negative correlation between transverse cardiac diameter and %LAA (ρ = −0.34; p < 0.01). Although inspiratory cardiac size was not correlated with any of the spirometric values, the maximum cardiac area and transverse diameter on expiratory scans were significantly correlated with the reduced airflow values on spirometry (p < 0.01). In patients with COPD, the transverse cardiac diameter decreased as the emphysema progressed. A smaller cardiac area on expiratory CT suggested the presence of large LVs, emphysema, and airflow limitation in COPD.

Proinflammatory Cytokines Impair Vitamin D-Induced Host Defense in Cultured Airway Epithelial Cells

Vitamin D is a regulator of host defense against infections and induces expression of the antimicrobial peptide hCAP18/LL-37. Vitamin D deficiency is associated with chronic inflammatory lung diseases and respiratory infections. However, it is incompletely understood if and how (chronic) airway inflammation affects vitamin D metabolism and action. We hypothesized that long-term exposure of primary bronchial epithelial cells to proinflammatory cytokines alters their vitamin D metabolism, antibacterial activity, and expression of hCAP18/LL-37. To investigate this, primary bronchial epithelial cells were differentiated at the air-liquid interface for 14 days in the presence of the proinflammatory cytokines, TNF-α and IL-1β (TNF-α/IL-1β), and subsequently exposed to vitamin D (inactive 25(OH)D₃ and active 1,25(OH)₂D₃). Expression of hCAP18/LL-37, vitamin D receptor, and enzymes involved in vitamin D metabolism (CYP24A1 and CYP27B1) was determined using quantitative PCR, Western blot, and immunofluorescence staining. Furthermore, vitamin D-mediated antibacterial activity was assessed using nontypeable Haemophilus influenzae. We found that TNF-α/IL-1β treatment reduced vitamin D-induced expression of hCAP18/LL-37 and killing of nontypeable H. influenzae. In addition, CYP24A1 (a vitamin D-degrading enzyme) was increased by TNF-α/IL-1β, whereas CYP27B1 (that converts 25(OH)D₃ to its active form) and vitamin D receptor expression remained unaffected. Furthermore, we have demonstrated that the TNF-α/IL-1β-mediated induction of CYP24A1 was, at least in part, mediated by the transcription factor specific protein 1, and the epidermal growth factor receptor-mitogen-activated protein kinase pathway. These findings indicate that TNF-α/IL-1β decreases vitamin D-mediated antibacterial activity and hCAP18/LL-37 expression via induction of CYP24A1 and suggest that chronic inflammation impairs protective responses induced by vitamin D.

Is periodontitis a comorbidity of COPD or can associations be explained by shared risk factors/behaviors?

COPD is recognized as having a series of comorbidities potentially related to common inflammatory processes. Periodontitis is one of the most common human inflammatory diseases and has previously been associated with COPD in numerous observational studies. As periodontitis and COPD are both chronic, progressive conditions characterized by neutrophilic inflammation with subsequent proteolytic destruction of connective tissue, it has been proposed that they share common pathophysiological processes. The mechanisms proposed to link COPD and periodontitis include mechanical aspiration of oral contents into the respiratory tree, overspill of locally produced inflammatory mediators into the systemic circulation or oral or lung-derived bacteremia activating an acute-phase response and also reactive oxygen species (ROS) and cytokine release by systemic neutrophils at distant sites. Studies of systemic neutrophils in COPD and chronic periodontitis describe altered cellular functions that would predispose to inflammation and tissue destruction both in the lung and in the mouth, again potentially connecting these conditions. However, COPD and periodontitis also share risk factors such as age, chronic tobacco smoke exposure, and social deprivation that are not always considered in observational and interventional studies. Furthermore, studies reporting associations have often utilized differing definitions of both COPD and periodontitis. This article reviews the current available evidence supporting the hypothesis that COPD and inflammatory periodontal disease (periodontitis) could be pathologically associated, including a review of shared inflammatory mechanisms. It highlights the potential limitations of previous studies, in particular, the lack of uniformly applied case definitions for both COPD and periodontitis and poor recognition of shared risk factors. Understanding associations between these conditions may inform why patients with COPD suffer such a burden of comorbid illness and new therapeutic strategies for both the diseases. However, further research is needed to clarify factors that may be directly causal as opposed to confounding relationships.

The recent advances of phenotypes in acute exacerbations of COPD

Exacerbations of COPD are clinically relevant events with therapeutic and prognostic implications. Yet, significant heterogeneity of clinical presentation and disease progression exists within acute exacerbations of COPD (AECOPD). Currently, different phenotypes have been widely used to describe the characteristics among patients with AECOPD. This has proved to be significant in the treatment and prediction of the outcomes of the disease. In this review of published literature, the phenotypes of AECOPD were classified according to etiology, inflammatory biomarkers, clinical manifestation, comorbidity, the frequency of exacerbations, and so on. This review concentrates on advancements in the use of phenotypes of AECOPD.

Biomarkers Predictive of Exacerbations in the SPIROMICS and COPDGene Cohorts

RATIONALE

Chronic obstructive pulmonary disease exacerbations are associated with disease progression, higher healthcare cost, and increased mortality. Published predictors of future exacerbations include previous exacerbation, airflow obstruction, poor overall health, home oxygen use, and gastroesophageal reflux.

OBJECTIVES

To determine the value of adding blood biomarkers to clinical variables to predict exacerbations.

METHODS

Subjects from the SPIROMICS (Subpopulations and Intermediate Outcomes Measures in COPD Study) (n = 1,544) and COPDGene (Genetic Epidemiology of COPD) (n = 602) cohorts had 90 plasma or serum candidate proteins measured on study entry using Myriad-RBM multiplex panels. We defined total exacerbations as subject-reported worsening in respiratory health requiring therapy with corticosteroids and/or antibiotics, and severe exacerbations as those leading to hospitalizations or emergency room visits. We assessed retrospective exacerbations during the 12 months before enrollment and then documented prospective exacerbations in each cohort. Exacerbations were modeled for biomarker associations with negative binomial regression including clinical covariates (age, sex, percent predicted FEV1, self-reported gastroesophageal reflux, St. George's Respiratory Questionnaire score, smoking status). We used the Stouffer-Liptak test to combine P values for metaanalysis.

MEASUREMENTS AND MAIN RESULTS

Between the two cohorts, 3,471 total exacerbations (1,044 severe) were reported. We identified biomarkers within each cohort that were significantly associated with a history of exacerbation and with a future exacerbation, but there was minimal replication between the cohorts. Although established clinical features were predictive of exacerbations, of the blood biomarkers only decorin and α2-macroglobulin increased predictive value for future severe exacerbations.

CONCLUSIONS

Blood biomarkers were significantly associated with the occurrence of exacerbations but were not robust between cohorts and added little to the predictive value of clinical covariates for exacerbations.

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.

Frailty in Pulmonary and Critical Care Medicine

Conceptualized first in the field of geriatrics, frailty is a syndrome characterized by a generalized vulnerability to stressors resulting from an accumulation of physiologic deficits across multiple interrelated systems. This accumulation of deficits results in poorer functional status and disability. Frailty is a "state of risk" for subsequent disproportionate declines in health status following new exposure to a physiologic stressor. Two predominant models have emerged to operationalize the measurement of frailty. The phenotype model defines frailty as a distinct clinical syndrome that includes conceptual domains such as strength, activity, wasting, and mobility. The cumulative deficit model defines frailty by enumerating the number of age-related things wrong with a person. The biological pathways driving frailty include chronic systemic inflammation, sarcopenia, and neuroendocrine dysregulation, among others. In adults with chronic lung disease, frailty is independently associated with more frequent exacerbations of lung disease, all-cause hospitalization, declines in functional status, and all-cause mortality. In addition, frail adults who become critically ill are more likely develop chronic critical illness or severe disability and have higher in-hospital and long-term mortality rates. The evaluation of frailty appears to provide important prognostic information above and beyond routinely collected measures in adults with chronic lung disease and the critically ill. The study of frailty in these populations, however, requires multipronged efforts aimed at refining clinical assessments, understanding the mechanisms, and developing therapeutic interventions.

A Systematic Review of Diagnostic Biomarkers of COPD Exacerbation

The aims of this systematic review were to determine which blood-based molecules have been evaluated as possible biomarkers to diagnose chronic obstructive pulmonary disease (COPD) exacerbations (AECOPD) and to ascertain the quality of these biomarker publications. Patients of interest were those that have been diagnosed with COPD. MEDLINE, EMBASE, and CINAHL databases were searched systematically through February 2015 for publications relating to AECOPD diagnostic biomarkers. We used a modified guideline for the REporting of tumor MARKer Studies (mREMARK) to assess study quality. Additional components of quality included the reporting of findings in a replication cohort and the use of receiver-operating characteristics area-under-the curve statistics in evaluating performance. 59 studies were included, in which the most studied biomarkers were C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). CRP showed consistent elevations in AECOPD compared to control subjects, while IL-6 and TNF-α had variable statistical significance and results. mREMARK scores ranged from 6 to 18 (median score of 13). 12 articles reported ROC analyses and only one study employed a replication cohort to confirm biomarker performance. Studies of AECOPD diagnostic biomarkers remain inconsistent in their reporting, with few studies employing ROC analyses and even fewer demonstrating replication in independent cohorts.

In vitro modeling of COPD inflammation and limitation of p38 inhibitor - SB203580

Background

Systemic inflammation and steroid resistance are the hallmarks of COPD. We examined the impact of p38 inhibitor (SB203580) in in vitro assays of systemic inflammation using pulmonary cells and patients’ sera.

Objective and methods

Data from 66 COPD patients and 15 age-/sex-matched healthy controls were compared. Interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α), and CCL5 were measured in serum samples and culture media from peripheral blood mononuclear cells. The impact of sera on IL-10 and CCL5 expression in alveolar macrophage cell line (MH-S) was examined. The in vitro effects of SB203580 on lipopolysaccharide-induced inflammation were investigated.

Results

Peripheral blood mononuclear cells from Global initiative for chronic Obstructive Lung Disease (GOLD) D patients produced more CCL5 and TNF-α, and less IL-10 compared to GOLD A–C patients. SB203580 treatment suppressed CCL5 and TNF-α and stimulated IL-10 production; however, the effect of SB203580 on IL-10 was lower in the COPD group. Culture of MH-S cells with COPD serum showed a significant increase in CCL5 and a significant decrease in IL-10 compared to healthy serum. This effect was not suppressed with SB203580 treatment.

Conclusion

COPD serum has a potent proinflammatory effect on pulmonary cells. Inhibition of p38 phoshorylation had a limited effect in restoring impaired lymphocyte function and suppressing inflammation induced by COPD serum, implying important p38-independent inflammatory mechanisms in COPD.

Effect of Repeated Freezing and Thawing on Biomarker Stability in Plasma and Serum Samples

Objectives

The stability of circulating proteins can be affected by repeated freezing and thawing. The aim of our study was to identify the effect of repeated freezing and thawing on the plasma and serum concentrations of eight proteins [interferon-γ, interleukin (IL)-8, IL-15, IL-17A, matrix metalloproteinase (MMP)-7, tumor necrosis factor-α, vascular endothelial growth factor (VEGF), and VEGF receptor 2 (VEGF-R2)].

Methods

We assessed the concentration changes of these proteins in 30 plasma and serum samples subjected to three, four, or five freeze–thaw cycles, and compared these with the concentration changes in the samples that were subjected to two freeze–thaw cycles before analysis.

Results

Repeated freezing and thawing by up to five cycles did not modify the plasma and serum concentrations of interferon-γ, IL-8, and VEGF-R2, while levels of MMP-7, tumor necrosis factor-α, and VEGF were significantly changed in both plasma and serum samples. Moreover, MMP-7 and VEGF concentrations tended to increase with freeze–thaw cycles. They were more elevated in plasma samples (up to about 15%) than in serum samples (up to about 7%), suggesting that serum is the preferred sample type for the analysis of circulating proteins.

Conclusion

This is the first report on the effect of repeated freezing and thawing on plasma concentrations of MMP-7 and VEGF-R2. Our findings propose that researchers should consider the number of freeze–thaw cycles to select plasma or serum samples, depending on the type of analyte.

The stats are in: an update on statin use in COPD

COPD is a chronic inflammatory disease of the lungs associated with an abnormal inflammatory response to noxious particles, the most prevalent of which is cigarette smoke. Studies have demonstrated that cigarette smoking is associated with activation of the bone marrow, and chronic smoking can lead to the inflammatory changes seen in COPD. Due to the inflammatory nature of the disease, medications affecting the inflammatory pathway may have clinical benefit and are being evaluated. One such class of medications, HMG-CoA reductase inhibitors, have been evaluated in the COPD population. Early studies have suggested that HMG-CoA reductase inhibitors have a variety of benefits in COPD including improvements in inflammatory markers, exacerbation rates, and mortality rates. However, the majority of this data comes from retrospective cohort studies, suggesting the need for randomized controlled trials. Recently, two randomized controlled trials, STATCOPE and RODEO, evaluated the benefit of HMG-CoA reductase inhibitors in the COPD population and found no benefit in exacerbation rates and vascular or pulmonary function, respectively. These results are reflected in practice guidelines, which do not support the use of HMG-CoA reductase inhibitors for the purpose of reducing COPD exacerbations.

Association between serum interleukin-6 concentrations and chronic obstructive pulmonary disease: a systematic review and meta-analysis

Background. Interleukin-6 (IL-6) is an important pro-inflammatory cytokine and has been implicated to play a role in the systemic inflammation of patients with chronic obstructive pulmonary disease (COPD). We conducted this meta-analysis to assess the association between serum IL-6 concentrations and COPD.

Methods. PubMed and Embase were searched for eligible studies. Data were extracted by two investigators (Wei J, Xiong XF) independently and analyzed using Review Manager 5.3 and STATA 12.0 software. Standard mean differences (SMDs) and 95% confidence intervals (CI) were calculated.

Results. Thirty-three studies were included in this meta-analysis. The serum IL-6 concentrations were higher in patients with stable COPD than healthy controls (SMD = 0.65, 95% CI [0.51–0.79]). COPD patients without major comorbidities also showed higher IL-6 levels than healthy controls (SMD = 0.74, 95% CI [0.56–0.91]). COPD patients with an forced expiratory volume in one second (FEV₁) of either <50% predicted or >50% predicted had increased IL-6 concentrations compared to healthy controls (SMD = 0.77, 95% CI [0.48–1.05], SMD = 1.01, 95% CI [0.43–1.59], respectively). The serum IL-6 concentrations between mild-moderate and severe-very severe COPD patient groups were not found to be significant (SMD = −0.1, 95% CI [−0.65–0.44]).

Conclusions. This meta-analysis indicated that patients with stable COPD had higher serum IL-6 concentrations than healthy controls. No evidence showing positive or negative association between IL-6 concentrations and the severity of pulmonary function impairment was found. The correlation between IL-6 levels and pulmonary function was weak in different severities of stable COPD patients.

The transient but not resident (TBNR) microbiome: a Yin Yang model for lung immune system

The concept of microbial content of the lung is still controversial. What make this more complicated are controversial results obtaining from different methodologies about lung microbiome and the definition of "lung sterility". Lungs may have very low bacteria but are not completely germ-free. Bacteria are constantly entering from the upper respiratory tract, but are then quickly being cleared. We can find bacterial DNA in the lungs, but it is much harder to ask about living bacteria. Here, we propose that if there is any trafficking of the microorganisms in the lung, it should be a "Transient But Not Resident (TBNR)" model. So, we speculate a "Yin Yang model" for the lung immune system and TBNR. Despite beneficial roles of microbiome on the development of lung immune system, any disruption and alteration in the microbiota composition of upper and lower airways may trigger or lead to several diseases such as asthma, chronic obstructive pulmonary disease and mustard lung disease.

Targeting oxidant-dependent mechanisms for the treatment of COPD and its comorbidities

Chronic obstructive pulmonary disease (COPD) is an incurable global health burden and is characterised by progressive airflow limitation and loss of lung function. In addition to the pulmonary impact of the disease, COPD patients often develop comorbid diseases such as cardiovascular disease, skeletal muscle wasting, lung cancer and osteoporosis. One key feature of COPD, yet often underappreciated, is the contribution of oxidative stress in the onset and development of the disease. Patients experience an increased burden of oxidative stress due to the combined effects of excess reactive oxygen species (ROS) and nitrogen species (RNS) generation, antioxidant depletion and reduced antioxidant enzyme activity. Currently, there is a lack of effective treatments for COPD, and an even greater lack of research regarding interventions that treat both COPD and its comorbidities. Due to the involvement of oxidative stress in the pathogenesis of COPD and many of its comorbidities, a unique therapeutic opportunity arises where the treatment of a multitude of diseases may be possible with only one therapeutic target. In this review, oxidative stress and the roles of ROS/RNS in the context of COPD and comorbid cardiovascular disease, skeletal muscle wasting, lung cancer, and osteoporosis are discussed and the potential for therapeutic benefit of anti-oxidative treatment in these conditions is outlined. Because of the unique interplay between oxidative stress and these diseases, oxidative stress represents a novel target for the treatment of COPD and its comorbidities.

Interleukin-33 promotes inflammatory cytokine production in chronic airway inflammation

Interleukin (IL)-33, belonging to the IL-1 family, is a novel cytokine that plays an important role in several chronic inflammatory diseases. Its role in chronic airway inflammation that develops into COPD is widely unknown. To determine this, we identified the expression of IL-33 in human bronchial epithelial layer and detected the inflammatory effects of IL-33 stimulation and the relative signaling pathways in human bronchial epithelial (HBE) cells and peripheral blood mononuclear cells (PBMCs), respectively. In this study, the expression of IL-33 in human bronchial epithelial layer was upregulated in COPD patients compared with normal controls. The expressions of IL-6 and IL-8 were also increased in both HBE cells and PBMCs, stimulated by IL-33 alone or combining the cigarette smoke extract (CSE). And the increased expressions could be partially blocked by ST2-Fc and IL-1RacP-Fc in both HBE cells and PBMCs. The p42/p44 ERK inhibitor in HBE cells and the p38 MAPK inhibitor in PBMCs exerted similar effects. Our data showed that IL-33 could induce and enhance the expression of IL-6 and IL-8 in HBE cells and PBMCs of COPD patients via ST2/IL-1RacP pathway and MAPKs pathway. Thus, the IL-33 is a promoter of chronic airway inflammation that contributes to COPD development.

Chronic obstructive pulmonary disease: NHLBI Workshop on the Primary Prevention of Chronic Lung Diseases

Chronic obstructive pulmonary disease (COPD) is a complex set of conditions with multiple risk factors, disease mechanisms, and clinical manifestations. These characteristics make primary prevention of COPD challenging. Semantic issues related to prevalent and incident disease (e.g., the use of specific cut points on a continuous range) should not derail development of primary prevention initiatives. Potential targets for COPD prevention occur along the spectrum of disease development. Understanding risk factors early in life, whether specific to COPD or not, allows for study of interventions to optimize lung function at birth and to prolong the lung function plateau, potentially reducing the development of COPD. It is necessary to identify noninvasive ways to screen for early COPD in those at risk before progression to clinically significant disease. Identification of specific COPD subgroups, such as individuals with chronic bronchitis, those with α1-antitrypsin deficiency, or early radiographic changes with normal spirometry, may offer specific opportunities for primary prevention. A better understanding of why COPD progresses despite smoking cessation is needed. Future research initiatives should also focus on identifying the underlying mechanisms and relevant interventions for nonsmokers with COPD, a currently poorly studied group. Ultimately, preventing the development of COPD will serve to reduce the tremendous burden of this chronic disease worldwide.

Anaemia in chronic obstructive pulmonary disease: an insight into its prevalence and pathophysiology

Chronic obstructive pulmonary disease (COPD) is a major health problem, with increasing morbidity and mortality. There is a growing literature regarding the extra-pulmonary manifestations of COPD, which can have a significant impact on symptom burden and disease progression. Anaemia is one of the more recently identified co-morbidities, with a prevalence that varies between 4.9% and 38% depending on patient characteristics and the diagnostic criteria used. Systemic inflammation seems to be an important factor for its establishment and repeated bursts of inflammatory mediators during COPD exacerbations could further inhibit erythropoiesis. However, renal impairment, malnutrition, low testosterone levels, growth hormone level abnormalities, oxygen supplementation, theophylline treatment, inhibition of angiotensin-converting enzyme and aging itself are additional factors that could be associated with the development of anaemia. The present review evaluates the published literature on the prevalence and significance of anaemia in COPD. Moreover, it attempts to elucidate the reasons for the high variability reported and investigates the complex pathophysiology underlying the development of anaemia in these patients.

Mobile-phone-based home exercise training program decreases systemic inflammation in COPD: a pilot study

Background

Moderate-intensity exercise training improves skeletal muscle aerobic capacity and increased oxidative enzyme activity, as well as exercise tolerance in COPD patients.

Methods

To investigate whether the home-based exercise training program can reduce inflammatory biomarkers in patients with COPD, twelve patients using mobile phone assistance and 14 with free walk were assessed by incremental shuttle walk test (ISWT), spirometry, strength of limb muscles, and serum C-reactive protein (CRP) and inflammatory cytokines.

Results

Patients in the mobile phone group improved their ISWT walking distance, with decrease in serum CRP after 2 months, and sustained at 6 months. Patients in the control group had no improvement. Serum IL-8 in the mobile phone group was significantly reduced at 2, 3 and 6 months after doing home exercise training compared to baseline. IL-6 and TNF-α were significantly elevated at 3 and 6 months in control group, while there were no changes in mobile phone group. The strength of limb muscles was significantly greater compared to baseline at 3 and 6 months in the mobile phone group.

Conclusions

A mobile-phone-based system can provide an efficient home endurance exercise training program with improved exercise capacity, strength of limb muscles and a decrease in serum CRP and IL-8 in COPD patients. Decreased systemic inflammation may contribute to these clinical benefits. (Clinical trial registration No.: NCT01631019)

An official American Thoracic Society/European Respiratory Society statement: update on limb muscle dysfunction in chronic obstructive pulmonary disease

BACKGROUND

Limb muscle dysfunction is prevalent in chronic obstructive pulmonary disease (COPD) and it has important clinical implications, such as reduced exercise tolerance, quality of life, and even survival. Since the previous American Thoracic Society/European Respiratory Society (ATS/ERS) statement on limb muscle dysfunction, important progress has been made on the characterization of this problem and on our understanding of its pathophysiology and clinical implications.

PURPOSE

The purpose of this document is to update the 1999 ATS/ERS statement on limb muscle dysfunction in COPD.

METHODS

An interdisciplinary committee of experts from the ATS and ERS Pulmonary Rehabilitation and Clinical Problems assemblies determined that the scope of this document should be limited to limb muscles. Committee members conducted focused reviews of the literature on several topics. A librarian also performed a literature search. An ATS methodologist provided advice to the committee, ensuring that the methodological approach was consistent with ATS standards.

RESULTS

We identified important advances in our understanding of the extent and nature of the structural alterations in limb muscles in patients with COPD. Since the last update, landmark studies were published on the mechanisms of development of limb muscle dysfunction in COPD and on the treatment of this condition. We now have a better understanding of the clinical implications of limb muscle dysfunction. Although exercise training is the most potent intervention to address this condition, other therapies, such as neuromuscular electrical stimulation, are emerging. Assessment of limb muscle function can identify patients who are at increased risk of poor clinical outcomes, such as exercise intolerance and premature mortality.

CONCLUSIONS

Limb muscle dysfunction is a key systemic consequence of COPD. However, there are still important gaps in our knowledge about the mechanisms of development of this problem. Strategies for early detection and specific treatments for this condition are also needed.

Increased cardiovascular risk in patients with chronic obstructive pulmonary disease and the potential mechanisms linking the two conditions: a review

Cardiovascular diseases, especially coronary artery disease (CAD), are the leading causes of death in patients with chronic obstructive pulmonary disease (COPD). There is a high prevalence of common risk factors in the COPD/CAD patient population including smoking, sedentary lifestyle and low socio-economic status. However, various studies have shown that airflow limitation is an independent risk factor for cardiovascular diseases. Chronic low-grade systemic inflammation, oxidative stress and increased platelet activation have been widely reported to be pathophysiological links between COPD and atherosclerosis. Statins and inhaled corticosteroids have been investigated as potential therapeutic interventions in COPD that may lower cardiovascular risk. The goals of this review are to examine the evidence for increased cardiovascular risk in COPD patients, the possible mechanisms linking these two chronic conditions, to discuss possible predictors or markers of poor outcomes among patients diagnosed with both COPD and CAD, and the therapeutic options aimed at reducing cardiovascular risks associated with COPD.

The proportion and function of peripheral myeloid-derived suppressor cells do not correlate with systemic inflammation in chronic obstructive pulmonary disease

Myeloid-derived suppressor cells (MDSC) have been implicated in the regulation of chronic inflammation. Chronic obstructive pulmonary disease (COPD) involves persistent inflammation, but the role of MDSC has not been explored. Here, proportions of MDSC (CD14(-)HLA-DR(-)CD33(+)CD11b(+) cells) were quantified in peripheral blood mononuclear cells (PBMC) isolated from patients with 'stable' COPD (n = 12), smokers with no evidence of COPD (n = 11) and healthy non-smokers (n = 11). The proportions of MDSC were similar in all groups. MDSC function was assessed by comparing T-cell and cytokine responses of whole and MDSC-depleted PBMC stimulated with Staphylococcus enterotoxin-B (SEB). Depletion of MDSC did not enhance CD4(+) or CD8(+) T-cell activation and proliferation, or alter IFNγ and IL-17 production in response to SEB. However production of TGFβ decreased after depletion of MDSC, so MDSC may be a source of this cytokine. In conclusion, COPD was not associated with perturbations in the proportion or function of MDSC in peripheral blood.

[Nutritional abnormalities in chronic obstructive pulmonary disease]

Nutritional abnormalities are associated with chronic obstructive pulmonary disease with a frequency ranging from 2 to 50%, depending on the geographical area and the study design. Diagnostic tools include anthropometry, bioelectrical impedance, dual energy radioabsortiometry and deuterium dilution, being the body mass and the lean mass indices the most frequently used parameters. While the most important consequences of nutritional abnormalities are muscle dysfunction and exercise limitation, factors implicated include an imbalance between caloric intake and consumption, and between anabolic and catabolic hormones, inflammation, tobacco smoking, poor physical activity, hypoxemia, some drugs and aging/comorbidities. The most important molecular mechanism for malnutrition associated with chronic obstructive pulmonary disease appears to be the mismatching between protein synthesis and breakdown. Among the therapeutic measures proposed for these nutritional abnormalities are improvements in lifestyle and nutritional support, although the use of anabolic drugs (such as secretagogues of the growth hormone) offers a new therapeutic strategy.

Pathophysiology of muscle dysfunction in COPD

Muscle dysfunction often occurs in patients with chronic obstructive pulmonary disease (COPD) and may involve both respiratory and locomotor (peripheral) muscles. The loss of strength and/or endurance in the former can lead to ventilatory insufficiency, whereas in the latter it limits exercise capacity and activities of daily life. Muscle dysfunction is the consequence of complex interactions between local and systemic factors, frequently coexisting in COPD patients. Pulmonary hyperinflation along with the increase in work of breathing that occur in COPD appear as the main contributing factors to respiratory muscle dysfunction. By contrast, deconditioning seems to play a key role in peripheral muscle dysfunction. However, additional systemic factors, including tobacco smoking, systemic inflammation, exercise, exacerbations, nutritional and gas exchange abnormalities, anabolic insufficiency, comorbidities and drugs, can also influence the function of both respiratory and peripheral muscles, by inducing modifications in their local microenvironment. Under all these circumstances, protein metabolism imbalance, oxidative stress, inflammatory events, as well as muscle injury may occur, determining the final structure and modulating the function of different muscle groups. Respiratory muscles show signs of injury as well as an increase in several elements involved in aerobic metabolism (proportion of type I fibers, capillary density, and aerobic enzyme activity) whereas limb muscles exhibit a loss of the same elements, injury, and a reduction in fiber size. In the present review we examine the current state of the art of the pathophysiology of muscle dysfunction in COPD.