Interleukin-6 and interleukin-8 blood levels' poor association with the severity and clinical profile of ex-smokers with COPD

Distinct inflammatory profiles in mustard lung: A study of sulfur mustard-exposed patients with serious pulmonary complications

Mustard Lung (ML) refers to respiratory complications caused by sulfur mustard (SM) exposure, a chemical warfare agent. This study explores the inflammatory profile of SM-exposed veterans with serious ML, aiming to distinguish it from other respiratory diseases. The aim is also to comprehend the role of inflammatory markers in disease severity. A study was conducted on 257 male SM-exposed veterans and 64 unexposed control subjects. Inflammatory markers in serum and sputum samples were measured using the ELISA technique. Clinical evaluations identified the SM-exposed group as the patients with serious problems. Statistical analyses were conducted to compare groups. SM-exposed veterans exhibited decreased serum levels of IL-1α, IL-8, IL-17, GM-CSF, and NO compared to controls, while other markers did not differ significantly. Intriguingly, inflammatory patterns in ML subgroups, including those resembling Bronchiolitis Obliterans (BO), Chronic Bronchitis (CB), and asthma, differed from the corresponding cases of these diseases as reported in prior literature. Additionally, certain factors demonstrated notable decreases in concentration in severe ML cases compared to controls. The study reveals substantial changes in inflammatory markers in ML patients, highlighting their distinctive profile compared to other respiratory conditions. Despite some similarities with asthma, BO, and CB, the ML shows discernible variations in the levels of most inflammatory markers. Furthermore, the severity of ML impacted the serum levels of specific factors. These findings support the notion of classifying ML as a separate pulmonary condition, distinct from CB, BO, and asthma, opening avenues for further research and tailored treatment strategies.

Cardiovascular Diseases in COPD: From Diagnosis and Prevalence to Therapy

Chronic obstructive pulmonary disease (COPD) is considered one of the leading causes of mortality. Cardiovascular comorbidities are diagnosed often in COPD patients, not only because of the common risk factors these two diseases share, but also because of the systemic inflammation which characterizes COPD and has deleterious effects in the cardiovascular system. The comorbid cardiovascular diseases in COPD result in several difficulties in the holistic treatment of these patients and affect outcomes such as morbidity and mortality. Several studies have reported that mortality from cardiovascular causes is common among COPD patients, while the risk for acute cardiovascular events increases during COPD exacerbations and remains high for a long time even after recovery. In this review, we focus on the prevalence of cardiovascular comorbidities in COPD patients, presenting the evidence regarding the interaction of the pathophysiological pathways which characterize each disease. Furthermore, we summarize information regarding the effects of cardiovascular treatment on COPD outcomes and vice versa. Finally, we present the current evidence regarding the impact of cardiovascular comorbidities on exacerbations, quality of life and survival of COPD patients.

Analysis of pathogenesis and drug treatment of chronic obstructive pulmonary disease complicated with cardiovascular disease

Chronic obstructive pulmonary disease (COPD) is a disease characterized by persistent airflow limitation, and is associated with abnormal inflammatory responses in the lungs to cigarette smoke and toxic and harmful gases. Due to the existence of common risk factors, COPD is prone to multiple complications, among which cardiovascular disease (CVD) is the most common. It is currently established that cardiovascular comorbidities increase the risk of exacerbations and mortality from COPD. COPD is also an independent risk factor for CVD, and its specific mechanism is still unclear, which may be related to chronic systemic inflammation, oxidative stress, and vascular dysfunction. There is evidence that chronic inflammation of the airways can lead to destruction of the lung parenchyma and decreased lung function. Inflammatory cells in the airways also generate reactive oxygen species in the lungs, and reactive oxygen species further promote lung inflammation through signal transduction and other pathways. Inflammatory mediators circulate from the lungs to the whole body, causing intravascular dysfunction, promoting the formation and rupture of atherosclerotic plaques, and ultimately leading to the occurrence and development of CVD. This article reviews the pathophysiological mechanisms of COPD complicated by CVD and the effects of common cardiovascular drugs on COPD.

The strong correlation between ADAM33 expression and airway inflammation in chronic obstructive pulmonary disease and candidate for biomarker and treatment of COPD

Airway inflammation in patients with chronic obstructive pulmonary disease (COPD) is an amplified response of the normal immune system that occurs as a result of chronic irritation by toxic substances, such as cigarette smoke. This leads to the characteristic pathological changes in the inflammatory cells of COPD patients. ADAM33 has been reported to be involved in the pathogenesis of COPD in East Asia by affecting airway inflammation and other immune responses. The aim of this study was to determine the potential role of ADAM33 (mRNA and soluble levels) as a biomarker of inflammation in COPD patients. This is a case control study using consecutive sampling. The COPD case and control (non-COPD) groups comprised 37 and 29 patients, respectively. We used univariate analysis to assess differences in the parameters between the groups and bivariate analysis to non-parametrically compare these parameters between the two groups. We observed significantly higher mRNA levels of ADAM33 in the COPD patients (10.39 ± 1.76) as compared to that in the non-COPD individuals (6.93 ± 0.39; P < 0.001). The levels of soluble ADAM33 were also significantly higher in the COPD patients (2.188 ± 1.142 ng/ml) compared to the non-COPD individuals (0.487 ± 0.105 ng/ml; P < 0.001). The mRNA and soluble ADAM33 levels were significantly higher in COPD patients compared to those in the parameter-matched non-COPD individuals. Thus, ADAM33 is a potential biomarker and treatment for inflammation in COPD patients.

Metabolic Fingerprinting Uncovers the Distinction Between the Phenotypes of Tuberculosis Associated COPD and Smoking-Induced COPD

Background: Although smoking is considered the main cause of chronic obstructive pulmonary disease (COPD), several other risk factors, including pulmonary tuberculosis (TB), contribute significantly to disease causation, particularly in developing countries. However, the underlying pathogenesis of TB-associated COPD (T-COPD) is unclear. Moreover, the need for prompt diagnosis and treatment of T-COPD to decrease the future burden of inflammation is underestimated. This study aimed to identify distinctive endogenous metabotypes of T-COPD, compared to smoking-associated COPD (S-COPD). Methods: Cross-sectional metabolomic analyses and clinical examinations of serum samples were performed for three groups of 168 male subjects: T-COPD (n = 59), S-COPD (n = 70), and healthy normal controls (n = 39). To retain a broad spectrum of metabolites, we performed technically distinct analyses (global metabolomic profiling using LC-QTOFMS and targeted analyses using LC-MS/MS). Results: Higher levels of IL-6 and C-reactive protein and St. George Respiratory Questionnaire scores were seen in the T-COPD group, compared to those in the S-COPD group. Global metabolomic profiling showed elevated metabolites, including arachidonic and eicosanoic acids, in the T-COPD group. Typical changes in tryptophan catabolism were observed through targeted profiling. Additionally, in the T-COPD group, kynurenine was elevated, and serotonin levels were reduced; therefore, indoleamine dioxygenase (IDO)/tryptophan hydroxylase (TPH) activities were dysregulated. Correlation analyses showed that changes in oxylipins were positively correlated with serum levels of IL-6 and C-reactive protein. Conclusion: Patients with TB-related COPD have enhanced inflammatory responses that may be linked to fatty acid pathways and tryptophan catabolism, which could be novel therapeutic targets for T-COPD.

The AGE-RAGE Axis and RAGE Genetics in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a heterogeneous group of lung diseases limiting the airflow due to narrowing of airways, chronic bronchitis and emphysema that leads to difficulties in breathing. Chronic inflammation is another important characteristic of COPD which leads to immune cell infiltration and helps in the alveolar destruction. Pathology of COPD is driven by various environmental and genetic factors. COPD is mainly associated with the inhalation of toxic agents mainly the cigarette smoke. Receptor for advanced glycation end products (RAGE) has emerged as a pattern recognition receptor and is a multiligand receptor expressed moderately in various cells, tissues and highly in the lungs throughout life. RAGE recognizes various ligands produced by cigarette smoke and its role has been implicated in the pathogenesis of COPD. RAGE ligands have been reported to accumulate in the lungs of patients with COPD. RAGE is a membrane receptor but its truncated form i.e. soluble RAGE (sRAGE) mainly functions as a contender of RAGE and inhibits various RAGE dependent cell signalling. Among the various ligands of RAGE, advanced glycation end products (AGEs) are majorly linked with COPD. Accumulated AGE triggers downstream RAGE-AGE axis in COPD. Moreover, RAGE genetics has long been known to play a vital role in the pathology of various airway diseases including COPD and this gene contains an associated locus. A reliable biomarker is needed for the management of this disease. sRAGE has an inverse correlation with the RAGE showed its importance as a valuable marker in COPD. This review is focused on the role of RAGE, sRAGE, RAGE axis and RAGE genetics in COPD.

Fine-particulate matter aggravates cigarette smoke extract-induced airway inflammation via Wnt5a-ERK pathway in COPD

Background

Exposure to environmental particulate matter (PM) ≤2.5 μm in diameter (PM_2.5) and smoking are common contributors to COPD, and pertinent research implicates both factors in pulmonary inflammation. Using in vivo mouse and in vitro human cellular models, we investigated the joint impact of PM_2.5 pollution, and cigarette smoke (CS) in mice or cigarette-smoke extract (CSE) in cells on COPD inflammation, and explored potential mechanisms.

Methods

Tissue changes in lungs of C57BL/6 mice exposed to PM_2.5 and CS were studied by light microscopy, H&E, immunochemistry, and immunofluorescence-stained sections. Levels of inflammatory factors induced by PM_2.5/CS in mice and PM_2.5/CSE in 16HBE cells were also monitored by quantitative reverse-transcription (qRT)-PCR and ELISA. Expression of genes related to the Wnt5a-signaling pathway was assessed at transcriptional and protein levels using immunofluorescence, qRT-PCR, and Western blotting.

Results

Inflammatory response to combined exposure of PM_2.5 and CS or CSE in mouse and 16HBE cells surpassed responses incited separately. Although separate PM_2.5 and CS/CSE exposure upregulated the expression of Wnt5a (a member of the Wnt-secreted glycoprotein family), combined PM_2.5 and CS/CSE exposure produced a steeper rise in Wnt5a levels. Use of a Wnt5a antagonist (BOX5) successfully blocked related inflammatory effects. ERK phosphorylation appeared to mediate the effects of Wnt5a in the COPD model, promoting PM_2.5 aggravation of CS/CSE-induced airway inflammation.

Conclusion

Our findings suggest that combined PM_2.5 and CS/CSE exposure induce airway inflammation and Wnt5a expression in vivo in mice and in vitro in 16HBE cells. Furthermore, PM_2.5 seems to aggravate CS/CSE-induced inflammation via the Wnt5a–ERK pathway in the context of COPD.

New frontiers in the treatment of comorbid cardiovascular disease in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a disease characterised by persistent airflow limitation that is not fully reversible and is currently the fourth leading cause of death globally. It is now well established that cardiovascular-related comorbidities contribute to morbidity and mortality in COPD, with approximately 50% of deaths in COPD patients attributed to a cardiovascular event (e.g. myocardial infarction). Cardiovascular disease (CVD) and COPD share various risk factors including hypertension, sedentarism, smoking and poor diet but the underlying mechanisms have not been fully established. However, there is emerging and compelling experimental and clinical evidence to show that increased oxidative stress causes pulmonary inflammation and that the spill over of pro-inflammatory mediators from the lungs into the systemic circulation drives a persistent systemic inflammatory response that alters blood vessel structure, through vascular remodelling and arterial stiffness resulting in atherosclerosis. In addition, regulation of endothelial-derived vasoactive substances (e.g. nitric oxide (NO)), which control blood vessel tone are altered by oxidative damage of vascular endothelial cells, thus promoting vascular dysfunction, a key driver of CVD. In this review, the detrimental role of oxidative stress in COPD and comorbid CVD are discussed and we propose that targeting oxidant-dependent mechanisms represents a novel strategy in the treatment of COPD-associated CVD.

Defining the role of neutrophil-to-lymphocyte ratio in COPD: a systematic literature review

COPD is characterized by a pulmonary and systemic inflammatory process. Several authors have reported the elevation of multiple inflammatory markers in patients with COPD; however, their use in routine clinical practice has limitations. The neutrophil-to-lymphocyte ratio (NLR) is a useful and cost-effective inflammatory marker derived from routine complete blood count. We performed a systematic literature review using the PRISMA statement. Twenty-two articles were included, recruiting 7,601 COPD patients and 784 healthy controls. Compared with controls, COPD patients had significantly higher NLR values. We found a significant correlation between the NLR and clinical/functional parameters (FEV₁, mMRC, and BODE index) in COPD patients. Elevation of the NLR is associated with the diagnosis of acute exacerbation of COPD (pooled data propose a cut-off value of 3.34 with a median sensitivity, specificity, and area under the curve of 80%, 86%, and 0.86, respectively). Additionally, increased NLR is also associated with the diagnosis of a bacterial infection in exacerbated patients, with a cut-off value of 7.30, although with a low sensitivity and specificity. The NLR is an independent predictor of in-hospital and late mortality after exacerbation. In conclusion, the NLR could be a useful marker in COPD patients; however, further studies are needed to better identify the clinical value of the NLR.

Association of Elevated Serum GM-CSF, IFN-γ, IL-4, and TNF-α Concentration with Tobacco Smoke Induced Chronic Obstructive Pulmonary Disease in a South Indian Population

Background

Chronic obstructive pulmonary disease (COPD) is a devastating condition with limited pharmacotherapeutic options and exceptionally high public-health burden globally as well as in India. Tobacco smoking is the primary cause for COPD among men in India. Systemic inflammation involving altered regulation of cytokines controlling the host defense mechanism is a hallmark of COPD pathogenesis. However, biomarker discovery studies are limited among Indian COPD patients.

Methods

We assessed the serum concentrations [median (25th-75th percentile) pg/ml] of interleukin (IL)-2,4,6,8,10, granulocyte macrophage colony stimulating factor (GM-CSF), interferon gamma (IFN-γ), and tumor necrosis factor alpha (TNF-α) using a multiplexed immunoassay. Our study cohort consisted of 30 tobacco smokers with COPD (TS COPD) and 20 tobacco smokers without COPD (TS CONTROL) from South India. The study population was matched for age, sex (male), and tobacco consumption (pack-years). COPD was diagnosed according to the global initiative for chronic obstructive lung disease (GOLD) criteria of persistent airflow obstruction determined by the ratio of postbronchodilator forced expiratory volume in 1 second/forced vital capacity (FEV₁/FVC) of <0.7. A validated structured questionnaire-based survey [Burden of Obstructive Lung Disease (BOLD) study] and spirometry were performed during house to house visit of the field study. Statistical analysis included nonparametric (two-tailed) Mann-Whitney U and Spearman rank test, as appropriate (significance: p<0.05).

Results

Serum GM-CSF [69.64 (46.67, 97.48); 36.78 (30.07, 53.88), p=0.014], IFN-γ [51.06 (17.00, 84.86); 11.70 (3.18, 32.81), p=0.017], IL-4 [9.09 (1.8, 19.9); 1.8 (1.8, 4.46); p=0.024], and TNF-α [20.68 (5.5, 29.26); 3.5 (3.5, 4.5); p<0.001] concentrations (pg/ml) were increased in TS COPD subjects compared to TS CONTROL. A weak correlation between lung function parameters and cytokine concentrations was detected.

Conclusion

Our pilot study reveals GM-CSF, IFN-γ, IL-4, and TNF-α as plausible COPD susceptibility biomarkers within the investigated South Indian population that needs to be validated in a larger cohort.

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.

Plasma Inflammatory Cytokine IL-4, IL-8, IL-10, and TNF-α Levels Correlate with Pulmonary Function in Patients with Asthma-Chronic Obstructive Pulmonary Disease (COPD) Overlap Syndrome

Background

The aim of this study was to investigate the plasma inflammatory cytokine levels and their correlations with pulmonary function in patients with asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS).

Material/Methods

Between January 2013 and December 2014, a total of 96 patients with asthma, acute exacerbation of chronic obstructive pulmonary disease (AECOPD), or ACOS were enrolled, and 35 healthy people were included as a control group. Fasting plasma interleukin (IL)-4, IL-8, IL-10, and tumor necrosis factor alpha (TNF-α) levels were detected using enzyme-linked immunosorbent assay (ELISA). Correlations between the plasma inflammatory cytokine levels and forced expiratory volume in 1 second (FEV1), FEV1/predicted value ratio (FEV1%pred), and FEV1/forced vital capacity (FVC) were analyzed.

Results

IL-4 and IL-8 levels showed statistically significant differences among the 3 groups of patients (both P<0.001); IL-4 level was significantly lower, while IL-8 level was significantly higher in the AECOPD group and ACOS group than those in the asthma group (all P<0.05). IL-10 level and TNF-α level were significantly different among the 3 patient groups (both P<0.001). IL-10 level was significantly different between each of the 2 groups (all P<0.001). TNF-α level in the asthma group was higher than in the AECOPD group and ACOS group (both P<0.001). IL-4 and IL-10 were positively and IL-8 and TNF-α were negatively related with FEV1, FEV1%pred, and FEV1/FVC.

Conclusions

Plasma levels of inflammatory cytokines IL-4, IL-8, IL-10, and TNF-α are related with severity of airway diseases and could be potential markers for the evaluation of asthma, COPD, and ACOS.

Multiple Circulating Cytokines Are Coelevated in Chronic Obstructive Pulmonary Disease

Inflammatory biomarkers, including cytokines, are associated with COPD, but the association of particular circulating cytokines with systemic pathology remains equivocal. To investigate this, we developed a protein microarray system to detect multiple cytokines in small volumes of serum. Fourteen cytokines were measured in serum from never-smokers, ex-smokers, current smokers, and COPD patients (GOLD stages 1–3). Certain individual circulating cytokines (particularly TNFα and IL-1β) were significantly elevated in concentration in the serum of particular COPD patients (and some current/ex-smokers without COPD) and may serve as markers of particularly significant systemic inflammation. However, numerous circulating cytokines were raised such that their combined, but not individual, elevation was significantly associated with severity of disease, and these may be further indicators of, and contributors to, the systemic inflammatory manifestations of COPD. The coelevation of numerous circulating cytokines in COPD is consistent with the insidious development, chronic nature, and systemic comorbidities of the disease.

Chemical constituents of tobacco smoke induce the production of interleukin-8 in human bronchial epithelium, 16HBE cells

Background

Interleukin-8 (IL-8) functions as a major chemoattractant and plays pivotal roles in the initiation and development of chronic obstructive pulmonary disease (COPD), and tobacco smoke is a most risk factor contributing to the development of COPD. Hence, we have screened some of the tobacco smoke-derived chemical compounds that potentially induce the production of IL-8 in human bronchial epithelium, 16HBE cells.

Methods

Twenty-eight hazardous smoke components belonging to 9 classes including nicotine, ammonia, aromatic amines, polycyclic aromatic hydrocarbons, phenols, carbonyls, hydrocyanic acid, nitrosamines and other volatile organics were used in the experiments. Proliferation of 16HBE cells was determined by cell counting kit-8 kit, luciferase activity was measured in IL-8 reporter gene-expressing 16HBE cells, and IL-8 levels in culture supernatants were quantified by enzyme-linked immunosorbent assay.

Results

At the non-toxic dosages, chemical compounds belonging to nicotine, aromatic amines, benzopyrene, phenols, aldehydes, and some other volatile organics dose-dependently increased IL-8 reporter gene expression. Consistently, the representative compounds belonging to nicotine, aromatic amines, benzopyrene, phenols, aldehydes, and some other volatile organics significantly and dose-dependently increased IL-8 levels in the culture supernatants of 16HBE cells, among these compounds, benzopyrene is a most potent stimulator for inducing IL-8 production.

Conclusions

The present study has identified particular tobacco smoke constituents responsible for inducing the IL-8 production in human bronchial epithelium, which might help shed light on the pathogenesis of tobacco smoke-induced COPD.

Serum Interleukin-6 Levels and Pulmonary Function in Ataxia-Telangiectasia

OBJECTIVE

To evaluate the potential link between systemic inflammation and impaired lung function in people with ataxia-telangiectasia (A-T), we hypothesized that serum levels of interleukin (IL)-6, a proinflammatory cytokine, would correlate inversely with lung function in subjects with A-T.

STUDY DESIGN

Consecutive subjects with A-T were recruited from the Johns Hopkins Outpatient A-T Clinical Center. Serum levels of IL-6 and 8 were measured by enzyme-linked immunosorbent assay. Spirometry was performed in subjects ≥ 6 years of age on the same day that serum was obtained for measurements of cytokines.

RESULTS

Approximately 80% of subjects had elevated serum IL-6 levels (> 1.0 pg/mL). No association was found between elevated IL-6 and age. Elevated IL-8 levels were found in 23.6% of subjects, and all subjects with elevated IL-8 levels had elevated IL-6 levels. Subjects with elevated IL-6 levels (mean: 6.14 ± 7.47 pg/mL) had significantly lower mean percent forced vital capacity (FVC%, 50.5% ± 17.8%) compared with subjects with normal serum IL-6 levels (FVC% of 66.2 ± 16.1, P = .018). Greater IL-6 levels were associated with lower FVC% even after adjustment for receiving gamma globulin therapy (P = .024) and supplemental nutrition (P = .055).

CONCLUSIONS

An association was found between elevated serum IL-6 levels and lower lung function in subjects with A-T. In addition, subjects with both elevated IL-6 and IL-8 had the lowest mean lung function. These findings indicate that markers for systemic inflammation may be useful in identifying individuals with A-T at increased risk for lower lung function and may help in assessing response to therapy.

Cigarette smoke compounds induce cellular redox imbalance, activate NF-κB, and increase TNF-α/CRP secretion: a possible pathway in the pathogenesis of COPD

Cigarette smoke has always been considered as a risk factor for chronic obstructive pulmonary diseases (COPD). In this study, we have examined the effect of ten individual cigarette smoke compounds (nicotine, benzo[a]pyrene, naphthalene, formaldehyde, ammonia, acrylic acid, toluene, benzene, m-xylene, and hexamine) on glutathione S transferase (GST) activity, an important Phase II metabolic enzyme and their possible role in inflammatory pathophysiology leading to COPD. Lower Glutathione (GSH) levels and GST activity and higher CRP, TNF-α, and IL-6 levels were observed in COPD patients compared to age and gender-matched controls. Using human recombinant GST and plasma as well as erythrocytes collected from normal subjects this study demonstrates that out of the ten compounds, nicotine (5 mg mL^-1), benzo[a]pyrene (10 ng mL^-1), naphthalene (250 μg mL^-1), and formaldehyde (5 pg mL^-1) caused a significant decrease in recombinant, plasma, and erythrocyte GST activity. Further cell culture studies show that exposure to nicotine, benzo[a]pyrene, naphthalene, and formaldehyde caused a significant decrease in GSH levels and GST activity and its protein expression and an increase in intracellular ROS production in THP-1 monocytes. Interestingly, treatment with benzo[a]pyrene and naphthalene significantly up regulated the phosphorylation of the p65 subunit of NF-κB and increased the secretion of TNF-α and CRP compared to control. This study suggests the potential role of benzo[a]pyrene and naphthalene in the activation of the inflammatory signaling pathway leading to cigarette smoke-induced COPD.

Anti-inflammatory effects of potato extract on a rat model of cigarette smoke-induced chronic obstructive pulmonary disease

Highlights:

(1) Potato extract (PE) exhibits non-toxic effects on mice.

(2) Cigarette smoke (CS)–induced COPD rats exhibit significant thickened and disordered lung markings.

(3) PE could improve the histopathological symptoms of lung tissue in COPD.

(4) PE could increase the expression of IL-10 and reduce the expression of TNF-α and G-CSF in COPD rats.

Plasma Chemokine signature correlates with lung goblet cell hyperplasia in smokers with and without chronic obstructive pulmonary disease

Background

Chronic Obstructive Pulmonary Disease (COPD) is characterized by lung and systemic inflammation as well as airway goblet cell hyperplasia (GCH). Mucin production is activated in part by stimulation of the epidermal growth factor (EGF) receptor pathway through neutrophils and macrophages. How circulating cytokine levels relate to GCH is not clear.

Methods

We performed phlebotomy and bronchoscopy on 25 subjects (six nonsmokers, 11 healthy smokers, and eight COPD subjects FEV₁ 30–60 %). Six endobronchial biopsies per subject were performed. GCH was measured by measuring mucin volume density (MVD) using stereological techniques on periodic acid fast-Schiff stained samples. We measured the levels of chemokines CXCL8/IL-8, CCL2/MCP-1, CCL7/MCP-3, CCL22/MCD, CCL3/MIP-1α, and CCL4/MIP-1β, and the cytokines IL-1, IL-4, IL-6, IL-9, IL-17, EGF, and vascular endothelial growth factor (VEGF). Differences between groups were assessed using one-way ANOVA, t test, or Chi squared test. Post hoc tests after ANOVA were performed using Bonferroni correction.

Results

MVD was highest in healthy smokers (27.78 ± 10.24 μL/mm²) compared to COPD subjects (16.82 ± 16.29 μL/mm², p = 0.216) and nonsmokers (3.42 ± 3.07 μL/mm², p <0.0001). Plasma CXCL8 was highest in healthy smokers (11.05 ± 8.92 pg/mL) compared to nonsmokers (1.20 ± 21.92 pg/mL, p = 0.047) and COPD subjects (6.01 ± 5.90 pg/mL, p = 0.366). CCL22 and CCL4 followed the same trends. There were no significant differences in the other cytokines measured. When the subjects were divided into current smokers (healthy smokers and COPD current smokers) and non/ex-smokers (nonsmokers and COPD ex-smokers), plasma CXCL8, CCL22, CCL4, and MVD were greater in current smokers. No differences in other cytokines were seen. Plasma CXCL8 moderately correlated with MVD (r = 0.552, p = 0.003).

Discussion

In this small cohort, circulating levels of the chemokines CXCL8, CCL4, and CCL22, as well as MVD, attain the highest levels in healthy smokers compared to nonsmokers and COPD subjects. These findings seem to be driven by current smoking and are independent of airflow obstruction.

Conclusions

These data suggest that smoking upregulates a systemic pattern of neutrophil and macrophage chemoattractant expression, and this correlates significantly with the development of goblet cell hyperplasia.

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.