CD8 cells may contribute towards an autoimmune process in COPD. Down regulation of T cell receptor (TCR) signalling molecules occurs in autoimmune diseases with consequent T cell dysfunction. We hypothesise that TCR signalling is abnormal in COPD pulmonary CD8 cells. Micro-array gene expression analysis of blood and pulmonary COPD CD8 samples was performed and compared to pulmonary CD8 cells from smoker controls (S). We focused on the TCR signalling pathway, with validation of key findings using polymerase chain reaction and immunofluorescence. TCR signalling molecules in COPD pulmonary CD8 cells were down regulated compared to blood CD8 cells (CD247: fold change (FC) −2.43, Q = 0.001; LCK: FC −2.25, Q = 0.01). Micro-array analysis revealed no significant differences between COPD and S pulmonary CD8 cells. However, PCR revealed significantly lower gene expression levels of CD247 (FC −1.79, p = 0.04) and LCK (FC −1.77, p = 0.01) in COPD compared to S pulmonary CD8 cells. CD247 down regulation in COPD CD8 cells was confirmed by immunofluorescent staining of bronchoalveolar lavage cells: Significantly fewer COPD CD8 cells co-expressed CD247 compared to healthy non-smoker CD8 cells (mean 88.9 vs 75.2%, p<0.05) There is down regulation of TCR signalling molecules in COPD pulmonary CD8 cells. This may cause T cell dysfunction.
Previous studies of glucocorticoid receptor (GR) function in COPD lung macrophages have used dexamethasone to evaluate inhibition of cytokine production. We have now used the clinically relevant corticosteroid beclomethasone-17-monopropionate (17-BMP) to assess GR function in COPD lung macrophages, and investigated the transactivation of glucocorticoid sensitive genes and GR phosphorylation in addition to cytokine production. Lung macrophages were purified from surgically acquired lung tissue, from patients with COPD, smokers, and non-smokers. The transactivation of glucocorticoid sensitive genes (FKBP51 and GILZ) by 17-BMP were analysed by polymerase chain reaction. 17-BMP suppression of LPS-induced TNFα, IL-6 and CXCL8 was measured by ELISA and GR phosphorylation was measured by immunohistochemistry and Western blot. 17-BMP reduced cytokine release in a concentration dependent manner, with >70% inhibition of all cytokines, and no difference between COPD patients and controls. Similarly, the transactivation of FKBP51 and GILZ, and GR phosphorylation was similar between COPD patients and controls. In this context, GR function in COPD lung macrophages is unaltered. 17-BMP effectively suppresses cytokine production in COPD lung macrophages.
Air pollution by diesel exhaust particles is associated with elevated mortality and increased hospital admissions in individuals with respiratory diseases such as asthma and chronic obstructive pulmonary disease. During active inflammation monocytes are recruited to the airways and can replace resident alveolar macrophages. We therefore investigated whether chronic fourteen day exposure to low concentrations of diesel exhaust particles can alter the phenotype and function of monocytes from healthy individuals and those with chronic obstructive pulmonary disease. Monocytes were purified from the blood of healthy individuals and people with a diagnosis of chronic obstructive pulmonary disease. Monocyte-derived macrophages were generated in the presence or absence of diesel exhaust particles and their phenotypes studied through investigation of their lifespan, cytokine generation in response to Toll like receptor agonists and heat killed bacteria, and expression of surface markers. Chronic fourteen day exposure of monocyte-derived macrophages to concentrations of diesel exhaust particles >10 µg/ml caused mitochondrial and lysosomal dysfunction, and a gradual loss of cells over time both in healthy and chronic obstructive pulmonary disease individuals. Chronic exposure to lower concentrations of diesel exhaust particles impaired CXCL8 cytokine responses to lipopolysaccharide and heat killed E. coli, and this phenotype was associated with a reduction in CD14 and CD11b expression. Chronic diesel exhaust particle exposure may therefore alter both numbers and function of lung macrophages differentiating from locally recruited monocytes in the lungs of healthy people and patients with chronic obstructive pulmonary disease.
Non-invasive phenotyping of chronic respiratory diseases would be highly beneficial in the personalised medicine of the future. Volatile organic compounds can be measured in the exhaled breath and may be produced or altered by disease processes. We investigated whether distinct patterns of these compounds were present in chronic obstructive pulmonary disease (COPD) and clinically relevant disease phenotypes.
Breath samples from 39 COPD subjects and 32 healthy controls were collected and analysed using gas chromatography time-of-flight mass spectrometry. Subjects with COPD also underwent sputum induction. Discriminatory compounds were identified by univariate logistic regression followed by multivariate analysis: 1. principal component analysis; 2. multivariate logistic regression; 3. receiver operating characteristic (ROC) analysis.
Comparing COPD versus healthy controls, principal component analysis clustered the 20 best-discriminating compounds into four components explaining 71% of the variance. Multivariate logistic regression constructed an optimised model using two components with an accuracy of 69%. The model had 85% sensitivity, 50% specificity and ROC area under the curve of 0.74. Analysis of COPD subgroups showed the method could classify COPD subjects with far greater accuracy. Models were constructed which classified subjects with ≥2% sputum eosinophilia with ROC area under the curve of 0.94 and those having frequent exacerbations 0.95. Potential biomarkers correlated to clinical variables were identified in each subgroup.
The exhaled breath volatile organic compound profile discriminated between COPD and healthy controls and identified clinically relevant COPD subgroups. If these findings are validated in prospective cohorts, they may have diagnostic and management value in this disease.
Chronic obstructive pulmonary disease; Biomarkers; Breath tests; Metabolomics
Exercise limitation, dynamic hyperinflation, and exertional dyspnea are key features of symptomatic chronic obstructive pulmonary disease (COPD). We assessed the effects of glycopyrronium bromide (NVA237), a once-daily, long-acting muscarinic antagonist, on exercise tolerance in patients with moderate to severe COPD.
Patients were randomized to a cross-over design of once-daily NVA237 50 μg or placebo for 3 weeks, with a 14-day washout. Exercise endurance, inspiratory capacity (IC) during exercise, IC and expiratory volumes from spirometry, plethysmographic lung volumes, leg discomfort and dyspnea under exercise (Borg scales), and transition dyspnea index were measured on Days 1 and 21 of treatment. The primary endpoint was endurance time during a submaximal constant-load cycle ergometry test on Day 21.
A total of 108 patients were randomized to different treatment groups (mean age, 60.5 years; mean post-bronchodilator, forced expiratory volume in 1 second [FEV1] 57.1% predicted). Ninety-five patients completed the study. On Day 21, a 21% difference in endurance time was observed between patients treated with NVA237 and those treated with placebo (P < 0.001); the effect was also significant from Day 1, with an increase of 10%. Dynamic IC at exercise isotime and trough FEV1 showed significant and clinically relevant improvements from Day 1 of treatment that were maintained throughout the study. This was accompanied by inverse decreases in residual volume and functional residual capacity. NVA237 was superior to placebo (P < 0.05) in decreasing leg discomfort (Borg CR10 scale) on Day 21 and exertional dyspnea on Days 1 and 21 (transition dyspnea index and Borg CR10 scale at isotime). The safety profile of NVA237 was similar to that of the placebo.
NVA237 50 μg once daily produced immediate and significant improvement in exercise tolerance from Day 1. This was accompanied by sustained reductions in lung hyperinflation (indicated by sustained and significant improvements in IC at isotime), and meaningful improvements in trough FEV1 and dyspnea. Improvements in exercise endurance increased over time, suggesting that mechanisms beyond improved lung function may be involved in enhanced exercise tolerance. (ClinicalTrials.gov Identifier: NCT01154127).
COPD; dyspnea; FEV1; exercise tolerance; LAMA; NVA237
There are increased numbers of activated lymphocytes in the lungs of chronic obstructive pulmonary disease (COPD) patients. The clinical benefits of corticosteroids in COPD patients are limited. Our hypothesis is that lymphocytes play a role in this corticosteroid insensitivity.
To investigate the effects of the corticosteroid dexamethasone on lung lymphocyte cytokine production from patients with COPD compared to controls.
Cultured airway lymphocytes obtained by bronchoscopy from healthy non-smokers (HNS), smokers (S) and COPD patients were stimulated with phytohaemagglutinin (PHA) & phorbol myristate acetate (PMA), +/- dexamethasone. Supernatants were assayed for interleukin (IL)-2 and interferon (IFN)γ. Immunofluoresence was used to analyse changes in CD8 glucocorticoid receptor (GRα and GRβ) expression.
The inhibition of PHA/PMA stimulated IFNγ production by dexamethasone was reduced in COPD patients compared to HNS (p < 0.05 at concentrations from 0.1-1 μM). There was also a significant reduction (p < 0.05) in the mean inhibitory effect at 1 μM in COPD patients (54.1%) compared to smokers (72.1%), and in smokers compared to HNS (85.5%). There was a numerically reduced effect of dexamethasone on IL-2 production that did not reach statistical significance. There was no difference in GRα and GRβ expression in follicular CD8 cells between COPD patients (50.9% and 30.4% respectively) and smokers (52.9% and 29.7% respectively).
IFNγ production from COPD airway lymphocytes is corticosteroid insensitive. This phenomenon may be important in the poor clinical response often observed with corticosteroids.
COPD; Lymphocytes; Corticosteriods
Human small cell lung cancer (SCLC) is highly aggressive, and quickly develops resistance to therapy. SCLC cells are typically insensitive to glucocorticoids due to impaired glucocorticoid receptor (GR) expression. This is important as we have previously shown that expression of a GR transgene induces cell death in-vitro, and inhibits tumor growth in-vivo. However, the underlying mechanism for loss of GR expression is unknown. The SCLC cell line, DMS79, has low GR expression, compared to non-SCLC cell lines and normal bronchial epithelial cells. Retroviral GR expression in DMS79 cells caused activation of the apoptotic pathway as evidenced by marked induction of caspase-3 activity. Methylation analysis of the GR promoter revealed some methylation in the 1D, and 1E promoters of the GR gene, however the ubiquitous constitutively active 1C promoter was heavily methylated. In the 1C promoter there was a highly significant increase in DNA methylation in a panel of 14 human SCLC cell lines compared to a mixed panel of GR expressing, and non-expressing cell lines, and to peripheral blood mononuclear cells. Furthermore, within the panel of SCLC cell lines there was a significant negative correlation seen between methylation of the 1C promoter, and GR protein expression. Reversal of GR gene methylation with DNA methyltransferase inhibition caused increased GR mRNA and protein expression in SCLC but not non-SCLC cells. This resulted in increased Gc sensitivity, decreased Bcl-2 expression and increased caspase-3 activity in SCLC cells. These data suggest that DNA methylation decreases GR gene expression in human SCLC cells, in a similar manner to that for conventional tumor suppressor genes.
Pooled data were analyzed to evaluate the safety and tolerability of indacaterol, a once-daily inhaled long-acting β2-agonist for chronic obstructive pulmonary disease (COPD).
Patients and methods
Data were pooled from clinical studies of 3–12 months’ duration in patients with moderate-to-severe COPD receiving double-blind indacaterol 75 μg (n = 449), 150 μg (n = 2611), 300 μg (n = 1157), or 600 μg once daily (n = 547); formoterol 12 μg twice daily (n = 556); salmeterol 50 μg twice daily (n = 895); placebo (n = 2012); or tiotropium 18 μg once daily, given open label or blinded (n = 1214). Outcomes were adverse events, serious adverse events and deaths, plasma potassium, blood glucose, and QTc interval and vital signs.
The commonest adverse events with indacaterol were COPD worsening, nasopharyngitis, and headache; most cases were mild or moderate and incidence was generally similar to placebo and other active treatments. The risk of acute respiratory serious adverse events (leading to hospitalization, intubation, or death) was not significantly increased with any of the active treatments compared with placebo. COPD exacerbation rates (analyzed in the intent-to-treat population) were significantly reduced with all active treatments versus placebo. Hazard ratios versus placebo for major cardiovascular adverse events were <1 for all indacaterol doses. Notable values for vital signs and measures of systemic β2-adrenoceptor activity were rare with indacaterol. The number of deaths adjusted per patient-year was lower with indacaterol (all doses combined) than with placebo (relative risk 0.21 [95% confidence interval 0.07–0.660], P = 0.008).
Indacaterol has a good profile of safety and tolerability that is appropriate for the maintenance treatment of patients with COPD.
indacaterol; safety; tolerability; formoterol; salmeterol; tiotropium
Previous expression quantitative trait loci (eQTL) studies have performed genetic association studies for gene expression, but most of these studies examined lymphoblastoid cell lines from non-diseased individuals. We examined the genetics of gene expression in a relevant disease tissue from chronic obstructive pulmonary disease (COPD) patients to identify functional effects of known susceptibility genes and to find novel disease genes. By combining gene expression profiling on induced sputum samples from 131 COPD cases from the ECLIPSE Study with genomewide single nucleotide polymorphism (SNP) data, we found 4315 significant cis-eQTL SNP-probe set associations (3309 unique SNPs). The 3309 SNPs were tested for association with COPD in a genomewide association study (GWAS) dataset, which included 2940 COPD cases and 1380 controls. Adjusting for 3309 tests (p<1.5e-5), the two SNPs which were significantly associated with COPD were located in two separate genes in a known COPD locus on chromosome 15: CHRNA5 and IREB2. Detailed analysis of chromosome 15 demonstrated additional eQTLs for IREB2 mapping to that gene. eQTL SNPs for CHRNA5 mapped to multiple linkage disequilibrium (LD) bins. The eQTLs for IREB2 and CHRNA5 were not in LD. Seventy-four additional eQTL SNPs were associated with COPD at p<0.01. These were genotyped in two COPD populations, finding replicated associations with a SNP in PSORS1C1, in the HLA-C region on chromosome 6. Integrative analysis of GWAS and gene expression data from relevant tissue from diseased subjects has located potential functional variants in two known COPD genes and has identified a novel COPD susceptibility locus.
Rationale: Much effort is being made to discover noninvasive biomarkers of chronic airway disease that might enable better management, predict prognosis, and provide new therapeutic targets.
Objectives: To undertake a comprehensive, unbiased proteomic analysis of induced sputum and identify novel noninvasive biomarkers for chronic obstructive pulmonary disease (COPD).
Methods: Induced sputum was obtained from patients with COPD with a spectrum of disease severity and from control subjects. Two-dimensional gel electrophoresis and mass spectrometric identification of differentially expressed proteins were first applied to induced sputum from patients with GOLD stage 2 COPD and healthy smoker control subjects. Initial results thus obtained were validated by a combination of immunoassays (Western blotting and ELISA) applied to a large subject cohort. The biomarkers were localized to bronchial mucosa by immunohistochemistry.
Measurements and Main Results: Of 1,325 individual protein spots identified, 37 were quantitatively and 3 qualitatively different between the two groups (P < 0.05%). Forty protein spots were subjected to tandem mass spectrometry, which identified 15 separate protein species. Seven of these were further quantified in induced sputum from 97 individuals. Using this sequential approach, two of these potential biomarkers (apolipoprotein A1 and lipocalin-1) were found to be significantly reduced in patients with COPD when compared with healthy smokers. Their levels correlated with FEV1/FVC, indicating their relationship to disease severity.
Conclusions: A potential role for apolipoprotein A1 and lipocalin-1 in innate defense has been postulated previously; our discovery of their reduction in COPD indicates a deficient innate defense system in airway disease that could explain increased susceptibility to infectious exacerbations.
two-dimensional polyacrylamide gel electrophoresis; induced sputum; proteome; biomarkers; chronic obstructive pulmonary disease
COPD is an inflammatory disease with major co-morbidities. It has recently been suggested that depression may be the result of systemic inflammation. We aimed to explore the association between systemic inflammation and symptoms of depression and fatigue in patients with mainly moderate and clinically stable COPD using a range of inflammatory biomarkers, 2 depression and 2 fatigue scales.
We assessed 120 patients with moderate COPD (FEV1% 52, men 62%, age 66). Depression was assessed using the BASDEC and CES-D scales. Fatigue was assessed using the Manchester COPD-fatigue scale (MCFS) and the Borg scale before and after 6MWT. We measured systemic TNF-α, CRP, TNF-α-R1, TNF-α-R2 and IL-6.
A multivariate linear model of all biomarkers showed that TNF-α only had a positive correlation with BASDEC depression score (p = 0.007). TNF-α remained positively correlated with depression (p = 0.024) after further adjusting for TNF-α-R1, TNF-α-R2, 6MWD, FEV1%, and pack-years. Even after adding the MCFS score, body mass and body composition to the model TNF-α was still associated with the BASDEC score (p = 0.044). Furthermore, patients with higher TNF-α level (> 3 pg/ml, n = 7) had higher mean CES-D depression score than the rest of the sample (p = 0.03). Borg fatigue score at baseline were weakly correlated with TNF-α and CRP, and with TNF-α only after 6MWT. Patients with higher TNF-α had more fatigue after 6MWD (p = 0.054).
This study indicates a possible association between TNF-α and two frequent and major co-morbidities in COPD; i.e., depression and fatigue.
Two 1-year studies evaluated the long-term efficacy and safety of tiotropium 5 or 10 μg versus placebo, inhaled via the Respimat® Soft Mist™ Inhaler (SMI). The two studies were combined and had 4 co-primary endpoints (trough FEV1 response, Mahler Transition Dyspnea Index [TDI] and St George’s Respiratory Questionnaire scores all at week 48, and COPD exacerbations per patient-year). A total of 1990 patients with COPD participated (mean FEV1: 1.09 L). The mean trough FEV1 response of tiotropium 5 or 10 μg relative to placebo was 127 or 150 mL, respectively (both P < 0.0001). The COPD exacerbation rate was significantly lower with tiotropium 5 μg (RR = 0.78; P = 0.002) and tiotropium 10 μg (RR = 0.73; P = 0.0008); the health-related quality of life and Mahler TDI co-primary endpoints were significantly improved with both doses (both P < 0.0001). Adverse events were generally balanced except anticholinergic class effects, which were more frequent with active treatment. Fatal events occurred in 2.4% (5 μg), 2.7% (10 μg), and 1.6% (placebo) of patients; these differences were not significant. Tiotropium Respimat® SMI 5 μg demonstrated sustained improvements in patients with COPD relative to placebo and similar to the 10 μg dose but with a lower frequency of anticholinergic adverse events.
COPD; exacerbations; FEV1; quality of life; Respimat®; tiotropium
The percentage of neutrophils in sputum are increased in COPD patients, and may therefore be a biomarker of airway inflammation. We studied the relationships between sputum neutrophils and FEV1, health status, exacerbation rates, systemic inflammation and emphysema, and long term variability at 1 year.
Sputum samples were obtained from 488 COPD patients within the ECLIPSE cohort. 359 samples were obtained at baseline, and 297 after 1 year. 168 subjects provided samples at both visits. Serum interleukin-6 (IL-6), IL-8, surfactant protein D and C-reactive protein levels were measured by immunoassays. Low-dose CT scans evaluated emphysema.
Sputum neutrophil % increased with GOLD stage. There was a weak association between % sputum neutrophils and FEV1 % predicted (univariate r2 = 0.025 and 0.094 at baseline and year 1 respectively, p < 0.05 after multivariate regression). Similar weak but significant associations were observed between neutrophil % and health status measured using the St Georges Respiratory Questionairre. There were no associations between neutrophils and exacerbation rates or emphysema. Associations between sputum neutrophils and systemic biomarkers were non-significant or similarly weak. The mean change over 1 year in neutrophil % was an increase of 3.5%.
Sputum neutrophil measurements in COPD are associated weakly with FEV1 % predicted and health status. Sputum neutrophil measurements were dissociated from exacerbation rates, emphysema and systemic inflammation.
GSK256066 is a selective phosphodiesterase 4 inhibitor that can be given by inhalation, minimising the potential for side effects. We evaluated the effects of GSK256066 on airway responses to allergen challenge in mild asthmatics.
In a randomised, double blind, cross-over study, 24 steroid naive atopic asthmatics with both early (EAR) and late (LAR) responses to inhaled allergen received inhaled GSK256066 87.5 mcg once per day and placebo for 7 days, followed by allergen challenge. Methacholine reactivity was measured 24 h post-allergen. Plasma pharmacokinetics were measured. The primary endpoint was the effect on LAR.
GSK256066 significantly reduced the LAR, attenuating the fall in minimum and weighted mean FEV1 by 26.2% (p = 0.007) and 34.3% (p = 0.005) respectively compared to placebo. GSK256066 significantly reduced the EAR, inhibiting the fall in minimum and weighted mean FEV1 by 40.9% (p = 0.014) and 57.2% (p = 0.014) respectively compared to placebo. There was no effect on pre-allergen FEV1 or methacholine reactivity post allergen. GSK256066 was well tolerated, with low systemic exposure; plasma levels were not measurable after 4 hours in the majority of subjects.
GSK256066 demonstrated a protective effect on the EAR and LAR. This is the first inhaled PDE4 inhibitor to show therapeutic potential in asthma.
This study is registered on clinicaltrials.gov NCT00380354
IL-13 has been implicated in the development of airway inflammation and hyperresponsiveness. This study investigated the multiple-dose pharmacokinetics and safety profile of human anti-IL-13 antibody (CAT-354) in adults with asthma.
This was a multiple-dose, randomised, double-blind, placebo-controlled phase 1 study in asthmatics (forced expiratory volume in 1 second [FEV1] ≥ 80% predicted). Subjects were randomised to receive three intravenous infusions of CAT-354 (1 mg/kg, 5 mg/kg or 10 mg/kg) or placebo at 28-day intervals. Blood samples were taken for pharmacokinetic measurements. Safety was assessed by adverse events, vital signs, ECGs, laboratory and pulmonary function parameters.
Twenty-three subjects (aged 21-60 years, FEV1 88-95% predicted) received ≥ 1 dose of study medication. The half-life of CAT-354 was 12-17 days and was dose-independent. The maximum serum concentration and area under the curve were dose-dependent. Clearance (2.2-2.6 mL/day/kg) and volume of distribution (44-57 mL/kg) were both low and dose-independent. The observed maximum serum concentration after each dose increased slightly from dose 1 through dose 3 at all dose levels, consistent with an accumulation ratio of 1.4 to 1.7 for area under the curve. Most adverse events were deemed mild to moderate and unrelated to study medication. One SAE was reported and deemed unrelated to study drug. There were no effects of clinical concern for vital signs, ECG, laboratory or pulmonary parameters.
CAT-354 exhibited linear pharmacokinetics and an acceptable safety profile. These findings suggest that at the doses tested, CAT-354 can be safely administered in multiple doses to patients with asthma.
Inhalation of particulates is a leading cause of the development of lung diseases and current understanding of the complex relationship between lung metabolism and airborne particulates is incomplete. It is well established that mechanical load is important in the development of the lung and in lung cell differentiation. The interaction between particle exposure and physical forces on alveolar macrophages is a physiologically relevant issue, but as yet understudied. This study examines the effect of cyclic hydrostatic pressure and cotton particles on synthesis of cytokines by human alveolar macrophages.
Alveolar macrophages were obtained from patients with lung disease, either from lavage samples or from lung tissue resection. The commonly used cell line THP-1 was included in the experiments. Cell cultures were exposed to cotton particles and/cyclic hydrostatic pressure (3 or 5 psi); control cultures were exposed to medium only. TNFα, IL-1β and IL-6 were assayed in the culture media using specific ELISAs. Cells were characterized using morphology and markers specific for macrophages (Jenner/Giemsa staining, CD14 and CD68).
Exposure to cotton particles stimulated cytokine synthesis by macrophages from all three sources; exposure to cyclic hydrostatic pressure alone did not stimulate cytokine synthesis significantly. However, the combination of both particles and cyclic hydrostatic pressure increased the simulation of cytokine synthesis still further. Cell characterization demonstrated that the large majority of cells had a macrophage morphology and were positive for CD14 and CD68.
These data suggest an interaction between cyclic hydrostatic pressure and particulate exposure, which increases alveolar macrophage cytokine production. This interaction was only observed at the higher cyclic hydrostatic pressure. However, in patient samples, there was considerable variation in the amount by which secretion of an individual cytokine increased and there was also variation in the mechanosensitivity of cells from the three different sources. Cyclic hydrostatic pressure, therefore, may be an important modulator of the response of alveolar macrophages to cotton particles, but the source of the cells may be a confounding factor which demands further investigation.
Airway inflammation in COPD can be measured using biomarkers such as induced sputum and FeNO. This study set out to explore the heterogeneity of COPD using biomarkers of airway and systemic inflammation and pulmonary function by principal components analysis (PCA).
Subjects and Methods
In 127 COPD patients (mean FEV1 61%), pulmonary function, FeNO, plasma CRP and TNF-α, sputum differential cell counts and sputum IL8 (pg/ml) were measured. Principal components analysis as well as multivariate analysis was performed.
PCA identified four main components (% variance): (1) sputum neutrophil cell count and supernatant IL8 and plasma TNF-α (20.2%), (2) Sputum eosinophils % and FeNO (18.2%), (3) Bronchodilator reversibility, FEV1 and IC (15.1%) and (4) CRP (11.4%). These results were confirmed by linear regression multivariate analyses which showed strong associations between the variables within components 1 and 2.
COPD is a multi dimensional disease. Unrelated components of disease were identified, including neutrophilic airway inflammation which was associated with systemic inflammation, and sputum eosinophils which were related to increased FeNO. We confirm dissociation between airway inflammation and lung function in this cohort of patients.
Rationale: Overproduction of mucus is a contributory factor in the progression of chronic obstructive pulmonary disease (COPD). The polymeric mucins are major macromolecules in the secretion. Therefore, we hypothesized that the polymeric mucin composition or properties may be different in the sputum from individuals with COPD and smokers without airflow obstruction.
Objectives: To determine the major polymeric mucins in COPD sputum and whether these are different in the sputum from individuals with COPD compared with that from smokers without airflow obstruction.
Methods: The polymeric mucin composition of sputum from patients with COPD and smokers without airflow obstruction was analyzed by Western blotting analysis. The tissue localization of the mucins was determined by immunohistochemistry, and their size distribution was analyzed by rate–zonal centrifugation.
Measurements and Main Results: MUC5AC and MUC5B were the major mucins. MUC5AC was the predominant mucin in the smoker group, whereas MUC5B was more abundant from the patients with COPD, with a significant difference in the ratio of MUC5B to MUC5AC (P = 0.004); this ratio was correlated with FEV1 in the COPD group (r = 0.63; P = 0.01). The lower-charged glycosylated form of MUC5B was more predominant in COPD (P = 0.012). No significant associations were observed with respect to sex, age, or pack-year history. In both groups, MUC5AC was produced by surface epithelial cells and MUC5B by submucosal gland cells. Finally, there was a shift toward smaller mucins in the COPD group.
Conclusions: Our data indicate that there are differences in mucin amounts and properties between smokers with and without COPD. Further studies are needed to examine how this may impact disease progression.
chronic obstructive pulmonary disease; mucus; mucin; pathophysiology
Many of the systemic manifestations of chronic obstructive pulmonary disease (COPD) are mediated through increased systemic levels of inflammatory proteins. We assessed the long term repeatability of Interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) over one year and examined the relationships between these systemic markers in COPD.
Fifty-eight stable COPD patients completed a baseline and one-year visit. Serum IL-6, plasma CRP, and plasma TNF-α were measured. Repeatability was expressed by intraclass correlation coefficient (Ri) and the Bland–Altman method. Pearson correlations were used to determine the relationships between the systemic markers at both visits.
There was moderate repeatability with a very high degree of statistical significance (p ≤ 0.001) between the two visits for all the systemic biomarkers (IL-6, CRP, and TNF-α). CRP was significantly associated with IL-6 at both visits (r = 0.55, p = 0.0001, r = 0.51, p = 0.0002, respectively). There were no other significant associations between the systemic markers at either of the visits.
Systemic inflammatory biomarkers IL-6, CRP, and TNF-α were moderately repeatable over a twelve month period in COPD patients. We have also shown that a robust and repeatable association between IL-6 and CRP exists.
interleukin-6; tumor necrosis factor-α; C-reactive protein; repeatability; COPD
Glucocorticoid (GC) receptors (GRs) have profound anti-survival effects on human small cell lung cancer (SCLC). To explore the basis of these effects, protein partners for GRs were sought using a yeast two-hybrid screen. We discovered a novel gene, FAM33A, subsequently identified as a SKA1 partner and involved in mitosis, and so renamed Ska2. We produced an anti-peptide antibody that specifically recognized full-length human SKA2 to measure expression in human cell lines and tissues. There was a wide variation in expression across multiple cell lines, but none was detected in the liver cell line HepG2. A xenograft model of human SCLC had intense staining and archival tissue revealed SKA2 in several human lung and breast tumours. SKA2 was found in the cytoplasm, where it co-localized with GR, but nuclear expression of SKA2 was seen in breast tumours. SKA2 overexpression increased GC transactivation in HepG2 cells while SKA2 knockdown in A549 human lung epithelial cells decreased transactivation and prevented dexamethasone inhibition of proliferation. GC treatment decreased SKA2 protein levels in A549 cells, as did Staurosporine, phorbol ester and trichostatin A; all agents that inhibit cell proliferation. Overexpression of SKA2 potentiated the proliferative response to IGF-I exposure, and knockdown with shRNA caused cells to arrest in mitosis. SKA2 has recently been identified in HeLa S3 cells as part of a complex, which is critical for spindle checkpoint silencing and exit from mitosis. Our new data show involvement in cell proliferation and GC signalling, with implications for understanding how GCs impact on cell fate.
Limited information exists regarding measurement, reproducibility and interrelationships of non-invasive biomarkers in smokers. We compared exhaled breath condensate (EBC) leukotriene B4 (LTB4) and 8-isoprostane, exhaled nitric oxide, induced sputum, spirometry, plethysmography, impulse oscillometry and methacholine reactivity in 18 smokers and 10 non-smokers. We assessed the relationships between these measurements and within-subject reproducibility of EBC biomarkers in smokers. Compared to non-smokers, smokers had significantly lower MMEF % predicted (mean 64.1 vs 77.7, p = 0.003), FEV1/FVC (mean 76.2 vs 79.8 p = 0.05), specific conductance (geometric mean 1.2 vs 1.6, p = 0.02), higher resonant frequency (mean 15.5 vs 9.9, p = 0.01) and higher EBC 8-isoprostane (geometric mean 49.9 vs 8.9 pg/ml p = 0.001). Median EBC pH values were similar, but a subgroup of smokers had airway acidification (pH < 7.2) not observed in non-smokers. Smokers had predominant sputum neutrophilia (mean 68.5%). Repeated EBC measurements showed no significant differences between group means, but Bland Altman analysis showed large individual variability. EBC 8-isoprostane correlated with EBC LTB4 (r = 0.78, p = 0.0001). Sputum supernatant IL-8 correlated with total neutrophil count per gram of sputum (r = 0.52, p = 0.04) and with EBC pH (r = −0.59, p = 0.02). In conclusion, smokers had evidence of small airway dysfunction, increased airway resistance, reduced lung compliance, airway neutrophilia and oxidative stress.
smoking; exhaled breath condensate; exhaled nitric oxide; induced sputum; respiratory function tests
This study compared the effect of inhaled fluticasone propionate (FP) with the combination of salmeterol/fluticasone propionate (SFC) on lung function parameters in patients with mild asthma.
Adult patients with mild persistent asthma (≥ 80% predicted FEV1) receiving 200–500 μg of BDP or equivalent were randomised to receive either FP 100 μg or SFC 50/100 μg twice daily from a Diskus® inhaler for four weeks. The primary outcome was the change from baseline in airway resistance (sRaw) at 12 hrs post dose measured by whole body plethysmography. Impulse oscillometry and spirometry were also performed.
A comparison of the geometric mean sRaw at 12 hrs post dose in the SFC group to the FP group gave a ratio of 0.76 (0.66 – 0.89, p < 0.001) at week 2 and 0.81 (0.71 – 0.94, p = 0.006) at week 4. Similarly, significant results in favour of SFC for oscillometry measurements of resistance and reactance were observed. FEV1 was also significantly superior at week 2 in the SFC group (mean difference 0.16L, 95% CI; 0.03 – 0.28, p = 0.015), but not at week 4 (mean difference 0.17L, 95% CI -0.01 – 0.34, p = 0.060).
SFC is superior to FP in reducing airway resistance in mild asthmatics with near normal FEV1 values. This study provides evidence that changes in pulmonary function in patients with mild asthma are detected more sensitively by plethysmography compared to spirometry
Trial registration number