Smoking status and tumor necrosis factor-alpha mediated systemic inflammation in COPD patients

Relation between systemic inflammatory markers, peripheral muscle mass, and strength in limb muscles in stable COPD patients

The aim of this study was to investigate the association between systemic inflammatory mediators and peripheral muscle mass and strength in COPD patients. Fifty-five patients (69% male; age: 64±9 years) with mild/very severe COPD (defined as forced expiratory volume in the first second [FEV1] =54%±23%) were evaluated. We evaluated serum concentrations of IL-8, CRP, and TNF-α. Peripheral muscle mass was evaluated by computerized tomography (CT); midthigh cross-sectional muscle area (MTCSA) and midarm cross-sectional muscle area (MACSA) were obtained. Quadriceps, triceps, and biceps strength were assessed through the determination of the one-repetition maximum. The multiple regression results, adjusted for age, sex, and FEV1%, showed positive significant association between MTCSA and leg extension (0.35 [0.16, 0.55]; P=0.001), between MACSA and triceps pulley (0.45 [0.31, 0.58]; P=0.001), and between MACSA and biceps curl (0.34 [0.22, 0.47]; P=0.001). Plasma TNF-α was negatively associated with leg extension (-3.09 [-5.99, -0.18]; P=0.04) and triceps pulley (-1.31 [-2.35, -0.28]; P=0.01), while plasma CRP presented negative association with biceps curl (-0.06 [-0.11, -0.01]; P=0.02). Our results showed negative association between peripheral muscle mass (evaluated by CT) and muscle strength and that systemic inflammation has a negative influence in the strength of specific groups of muscles in individuals with stable COPD. This is the first study showing association between systemic inflammatory markers and strength in upper limb muscles.

Serum Vitamin A and Inflammatory Markers in Individuals with and without Chronic Obstructive Pulmonary Disease

BACKGROUND

Vitamin A is essential for the preservation and integrity of the lung epithelium and exerts anti-inflammatory effects.

OBJECTIVE

Evaluating vitamin A in the serum and sputum and testing its correlation with inflammatory markers in individuals with or without COPD. Methods. We evaluated dietary intake, serum and sputum vitamin A, tumor necrosis factor alpha, interleukin- (IL-) 6, IL-8, and C-reactive protein in 50 COPD patients (age = 64.0 ± 8.8 y; FEV1 (forced expiratory volume in the first second) (%) = 49.8 ± 16.8) and 50 controls (age = 48.5 ± 7.4 y; FEV1 (%) = 110.0 ± 15.7).

RESULTS

COPD exhibited lower serum vitamin A (1.8 (1.2-2.1) versus 2.1 (1.8-2.4) μmol/L, P < 0.001) and lower vitamin A intake (636.9 (339.6-1349.6) versus 918.0 (592.1-1654.6) RAE, P = 0.05) when compared with controls. Sputum concentration of vitamin A was not different between groups. Sputum vitamin A and neutrophils were negatively correlated (R (2) = -0.26; P = 0.03). Smoking (0.197, P = 0.042) exhibited positive association with serum vitamin A. COPD was associated with lower serum concentrations of vitamin A without relationship with the systemic inflammation.

CONCLUSIONS

Serum concentration of vitamin A is negatively associated with the presence of COPD and positively associated with smoking status. Sputum retinol is quantifiable and is negatively influenced by neutrophils. Although COPD patients exhibited increased inflammation it was not associated with serum retinol.

Identification of genetic variants in the TNF promoter associated with COPD secondary to tobacco smoking and its severity

Chronic obstructive pulmonary disease (COPD) is an inflammatory disease that arises in response to noxious particles or gases. Associations of genetic polymorphisms in TNF have been reported in Asians and Caucasians, but not in Mestizo populations. A case-control study was conducted in two stages: in the first stage, patients with COPD (COPD group, n=165) and smokers without disease (SNC group, n=165) were included and the TNF promoter sequence was determined using direct sequencing. In the second stage, the identified polymorphisms were validated by real-time polymerase chain reaction (PCR) in COPD (n=260) and SNC (n=506). In the first stage, 11 different sets of “contig” alignments were determined, of which contig 10 was found to be associated with susceptibility (P=5.0E-04, OR [odds ratio] =3.64) and contig 1 with Global Initiative for COPD (GOLD) greater grade (P=1.0E-02, OR =3.82). The single nucleotide polymorphisms found in this region were individually identified; the GA genotypes of rs1800629 (P=0.038, OR =2.07), rs56036015 (P=0.0082, OR =3.18), and rs361525 (P=1.0E-02, OR =4.220) were higher in the COPD group vs the SNC group; after second-stage validation, rs1800629 (P=6.00E-03, OR =2.26) and rs56036015 (P=1.10E-03, OR =2.54) are maintained. There are genetic variants in the TNF promoter associated with increased risk of COPD secondary to smoking and with a higher GOLD grade in the Mexican Mestizo population.

Neutrophils and emerging targets for treatment in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is characterized by a decreased airflow due to airway narrowing that, once it occurs, is not fully reversible. The disease usually is progressive and associated with an enhanced inflammatory response in the lungs after exposure to noxious particles or gases. After removal of the noxious particles, the inflammation can continue in a self-sustaining manner. It has been established that improper activation of neutrophils lies at the core of the pathology. This paper provides an overview of the mechanisms by which neutrophils can induce the pulmonary damage of COPD. As the pathogenesis of COPD is slowly being unraveled, new points of intervention are discovered, some of which with promising results.

TNF stimulation induces VHL overexpression and impairs angiogenic potential in skeletal muscle myocytes

Decreased skeletal muscle capillarization is considered to significantly contribute to the development of pulmonary cachexia syndrome (PCS) and progressive muscle wasting in several chronic inflammatory diseases, including chronic obstructive pulmonary disease (COPD). It is unclear to which extent the concurrent presence of systemic inflammation contributes to decreased skeletal muscle capillarization under these conditions. The present study was designed to examine in vitro the effects of the pro-inflammatory cytokine, tumor necrosis factor (TNF), on the regulation of hypoxia-angiogenesis signal transduction and capillarization in skeletal muscles. For this purpose, fully differentiated C2C12 skeletal muscle myocytes were stimulated with TNF and maintained under normoxic or hypoxic conditions. The expression levels of the putative elements of the hypoxia-angiogenesis signaling cascade were examined using qPCR, western blot analysis and immunofluorescence. Under normoxic conditinos, TNF stimulation increased the protein expression of anti-angiogenic von-Hippel Lindau (VHL), prolyl hydroxylase (PHD)2 and ubiquitin conjugating enzyme 2D1 (Ube2D1), as well as the total ubiquitin content in the skeletal muscle myocytes. By contrast, the expression levels of hypoxia-inducible factor 1‑α (HIF1-α) and those of its transcriptional targets, vascular endothelial growth factor (VEGF)A and glucose transporter 1 (Glut1), were markedly reduced. In addition, hypoxia increased the expression of the VHL transcript and further elevated the VHL protein expression levels in C2C12 myocytes following TNF stimulation. Consequently, an impaired angiogenic potential was observed in the TNF-stimulated myocytes during hypoxia. In conclusion, TNF increases VHL expression and disturbs hypoxia-angiogenesis signal transduction in skeletal muscle myocytes. The current findings provide a mechanism linking systemic inflammation and impaired angiogenesis in skeletal muscle. This is particularly relevant to further understanding the mechanisms mediating muscle wasting and cachexia in patients with chronic inflammatory diseases, such as COPD.

N-Acetylcysteine effects on transforming growth factor-β and tumor necrosis factor-α serum levels as pro-fibrotic and inflammatory biomarkers in patients following ST-segment elevation myocardial infarction

Background and Aims

Ischemia following acute myocardial infarction (AMI) increases the level of pro-fibrotic and inflammatory cytokines, including transforming growth factor (TGF)-β and tumor necrosis factor (TNF)-α. N-acetylcysteine (NAC) has therapeutic benefits in the management of patients with AMI. To the best of our knowledge, this is the first study that has evaluated the effect of NAC on TNF-α and TGF-β levels in patients with AMI.

Methods

Following confirmation of AMI, 88 patients were randomly administered NAC 600 mg (Fluimucil^®, Zambon, Ticino, Switzerland) or placebo orally twice daily for 3 days. For quantification of TGF-β and TNF-α serum levels after 24 and 72 h of NAC or placebo administration, peripheral venous blood (10 mL) samples were collected at these time points.

Results

Comparisons between levels of TGF-β and TNF-α after 24 and 72 h within the NAC or placebo groups revealed that there was not any significant difference except for TGF-β levels in the placebo group, which increased significantly over time (p = 0.042). Significant relationships existed between patients’ ejection fraction (p = 0.005) and TGF-β levels.

Conclusions

Receiving NAC could prevent TGF-β levels from increasing after 72 h as compared with not receiving NAC. As TGF-β had strong correlations with the ejection fraction, its antagonism seems to be important in the prevention of remodeling.

Association of polymorphisms of the receptor for advanced glycation end products gene with COPD in the Chinese population

The receptor for advanced glycation end products (RAGE) is a cell surface molecule of the immunoglobulin superfamily that binds diverse endogenous ligands involved in the development of chronic diseases and inflammatory damage. A growing body of evidence has suggested that RAGE is involved in the development and progression of chronic obstructive pulmonary disease (COPD). The present study investigated the existence of an association among three polymorphisms (-374T/A, -429T/C, and G82S) of the RAGE gene with the risk of COPD in the Chinese population. The RAGE genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism in 216 patients with COPD and 239 age-matched healthy individuals. Our study demonstrated that the frequencies of the GS genotype and the S allele in the G82S mutation were significantly higher in COPD patients than in controls (odds ratios [OR]=1.70, 95% confidence interval [CI]: 1.15-2.50, p=0.0098 and OR=1.42, 95% CI: 1.06-1.91, p=0.023, respectively). Further stratification analysis by smoking status revealed that the presence of the GS genotype conferred a higher risk of developing COPD in current smokers (p=0.044). In contrast, mutations at -374T/A and -429T/C did not demonstrate any association with COPD, even after taking into account the patients' smoking history. Our study provides preliminary evidence that the G82S polymorphism in the RAGE gene is associated with an increased risk of COPD and that the GS genotype of the G82S variant is a risk factor for COPD in the Chinese population.

Inhalation of glycopyrronium inhibits cigarette smoke-induced acute lung inflammation in a murine model of COPD

Glycopyrronium bromide (GB) is a muscarinic receptor antagonist that has been used as a long-acting bronchodilator in chronic obstructive pulmonary disease (COPD) patients. The aim of this study was to investigate the anti-inflammatory activity of inhaled GB in a cigarette smoke-induced acute lung inflammation mouse model. We found that aerosol pre-treatment with GB suppresses the accumulation of neutrophils and macrophages in the bronchoalveolar lavage fluid (BALF) in cigarette smoke (CS)-exposed mice. GB at doses of 300 and 600 μg/ml significantly inhibited the CS-induced increases in the mRNA and protein expression levels of interleukin (IL)-1β, tumor necrosis factor (TNF)-α, monocyte chemotactic protein (MCP)-1 and transforming growth factor (TGF)-β1 in lung tissues and the BALF. Moreover, GB at a dose of 600 μg/ml significantly inhibited the CS-induced changes in glutathione (GSH) and myeloperoxidase (MPO) activities in the BALF, decreased the CS-induced expression of matrix metalloproteinases (MMP)-9, and increased the CS-induced expression of tissue inhibitor of metalloproteinases (TIMP)-1, as determined through the immunohistochemical staining of lung tissue. Our results demonstrate the beneficial effects of inhaled GB on the inflammatory reaction in COPD.

Circulating hematopoietic progenitor cells are decreased in COPD

RATIONALE

Bone marrow derived progenitor cells participate in the repair of injured vessels. The lungs of individuals with emphysema have reduced alveolar capillary density and increased endothelial apoptosis. We hypothesized that circulating levels of endothelial and hematopoietic progenitor cells would be reduced in this group of patients.

OBJECTIVES

The goal of this study was to measure circulating levels of endothelial progenitor cells (EPCs) and hematopoietic progenitor cells (HPCs) in subjects with COPD and to determine if progenitor levels correlated with disease severity and the presence of emphysema.

METHODS

Peripheral blood mononuclear cells were isolated from 61 patients with COPD and 32 control subjects. Levels of EPCs (CD45(dim) CD34+) and HPCs (CD45(+) CD34(+) VEGF-R2(+)) were quantified using multi-parameter flow cytometry. Progenitor cell function was assessed using cell culture assays. All subjects were evaluated with spirometry and CT scanning.

MEASUREMENTS AND MAIN RESULTS

HPC levels were reduced in subjects with COPD compared to controls, whereas circulating EPC levels were similar between the two groups. HPC levels correlated with severity of obstruction and were lowest in subjects with severe emphysema. These associations remained after correction for factors known to affect progenitor cell levels including age, smoking status, the use of statin medications and the presence of coronary artery disease. The ability of mononuclear cells to form endothelial cell colony forming units (EC-CFU) was also reduced in subjects with COPD.

CONCLUSIONS

HPC levels are reduced in subjects with COPD and correlate with emphysema phenotype and severity of obstruction. Reduction of HPCs may disrupt maintenance of the capillary endothelium, thereby contributing to the pathogenesis of COPD.

Alterations in skeletal muscle cell homeostasis in a mouse model of cigarette smoke exposure

BACKGROUND

Skeletal muscle dysfunction is common in chronic obstructive pulmonary disease (COPD), a disease mainly caused by chronic cigarette use. An important proportion of patients with COPD have decreased muscle mass, suggesting that chronic cigarette smoke exposure may interfere with skeletal muscle cellular equilibrium. Therefore, the main objective of this study was to investigate the kinetic of the effects that cigarette smoke exposure has on skeletal muscle cell signaling involved in protein homeostasis and to assess the reversibility of these effects.

METHODS

A mouse model of cigarette smoke exposure was used to assess skeletal muscle changes. BALB/c mice were exposed to cigarette smoke or room air for 8 weeks, 24 weeks or 24 weeks followed by 60 days of cessation. The gastrocnemius and soleus muscles were collected and the activation state of key mediators involved in protein synthesis and degradation was assessed.

RESULTS

Gastrocnemius and soleus were smaller in mice exposed to cigarette smoke for 8 and 24 weeks compared to room air exposed animals. Pro-degradation proteins were induced at the mRNA level after 8 and 24 weeks. Twenty-four weeks of cigarette smoke exposure induced pro-degradation proteins and reduced Akt phosphorylation and glycogen synthase kinase-3β quantity. A 60-day smoking cessation period reversed the cell signaling alterations induced by cigarette smoke exposure.

CONCLUSIONS

Repeated cigarette smoke exposure induces reversible muscle signaling alterations that are dependent on the duration of the cigarette smoke exposure. These results highlights a beneficial aspect associated with smoking cessation.

Impaired exercise capacity and skeletal muscle function in a mouse model of pulmonary inflammation

Pulmonary TNFα has been linked to reduced exercise capacity in a subset of patients with moderate to severe chronic obstructive pulmonary disease (COPD). We hypothesized that prolonged, high expression of pulmonary TNFα impairs cardiac and skeletal muscle function, and both contribute to exercise limitation. Using a surfactant protein C promoter-TNFα construct, TNFα was overexpressed throughout life in mouse lungs (SP-C/TNFα+). TNFα levels in wild-type (WT) female serum and lung were two- and threefold higher than in WT male mice. In SP-C/TNFα+ mice, TNFα increased similarly in both sexes. Treadmill exercise was impaired only in male SP-C/TNFα+ mice. While increases in lung volume and airspace size induced by TNFα were comparable in both sexes, pulmonary hypertension along with lower body and muscle mass were evident only in male mice. Left ventricular (LV) function (cardiac output, stroke volume, LV maximal pressure, and LV maximal pressure dP/dt) was not altered by TNFα overexpression. Fatigue measured in isolated soleus and EDL was more rapid only in soleus of male SP-C/TNFα+ mice and accompanied by a loss of oxidative IIa fibers, citrate synthase activity, and PGC-1α mRNA and increase in atrogin-1 and MuRF1 expression also only in male mice. In situ gastrocnemius fatigue resistance, reflecting both oxygen availability and contractility, was decreased similarly in female and male SP-C/TNFα+ mice. These data indicate that male, but not female, mice overexpressing pulmonary TNFα are susceptible to exercise limitation, possibly due to muscle wasting and loss of the oxidative muscle phenotype, with protection in females possibly due to estrogen.

Three-year follow-up of Interleukin 6 and C-reactive protein in chronic obstructive pulmonary disease

BACKGROUND

Past studies have shown that mean values of Interleukin-6 (IL-6) and C-reactive protein (CRP) do not change significantly in COPD patients over a one-year period. However, longer period follow-up studies are still lacking. Thus, the aim of this study is to evaluate plasma CRP and IL-6 concentration over three years in COPD patients and to test the association between these inflammatory mediators and disease outcome markers.

METHODS

A cohort of 77 outpatients with stable COPD was evaluated at baseline, and 53 (mean FEV1, 56% predicted) were included in the prospective study. We evaluated Interleukin-6 (IL-6), C-reactive protein (CRP), six-minute walking distance (6MWD), and body mass index (BMI) at baseline and after three years. Plasma concentration of IL-6 was measured by high sensitivity ELISA, and CRP was obtained by high sensitivity particle-enhanced immunonephelometry.

RESULTS

IL-6 increased significantly after 3 years compared to baseline measurements [0.8 (0.5-1.3) vs 2.4 (1.3-4.4) pg/ml; p < 0.001] and was associated with worse 6MWD performance. In the Cox regression, increased IL-6 at baseline was associated with mortality [Hazard Ratio (95% CI) = 2.68 (0.13, 1.84); p = 0.02]. CRP mean values did not change [5 (1.6-7.9) vs 4.7 (1.7-10) pg/L; p = 0.84], although eleven patients (21%) presented with changes >3 mg/L in CRP after 3 years.

CONCLUSIONS

The systemic inflammatory process, evaluated by IL-6, seems to be persistent, progressive and associated with mortality and worse physical performance in COPD patients.

TRIAL REGISTRATION

No.:NCT00605540.

Functional polymorphisms in NFκB1/IκBα predict risks of chronic obstructive pulmonary disease and lung cancer in Chinese

Lung inflammation is the major pathogenetic feature for both chronic obstructive pulmonary disease (COPD) and lung cancer. The nuclear factor-kappa B (NFκB) and its inhibitor (IκB) play crucial roles in inflammatory. Here, we tested the hypothesis that single nucleotide polymorphisms (SNPs) in NFκB/IκB confer consistent risks for COPD and lung cancer. Four putative functional SNPs (NFκB1: -94del>insATTG; NFκB2: -2966G>A; IκBα: -826C>T, 2758G>A) were analyzed in southern and validated in eastern Chineses to test their associations with COPD risk in 1,511 COPD patients and 1,677 normal lung function controls, as well as lung cancer risk in 1,559 lung cancer cases and 1,679 cancer-free controls. We found that the -94ins ATTG variants (ins/del + ins/ins) in NFκB1 conferred an increased risk of COPD (OR 1.27, 95% CI 1.06-1.52) and promoted COPD progression by accelerating annual FEV1 decline (P = 0.015). The 2758AA variant in IκBα had an increased risk of lung cancer (OR 1.53, 95% CI 1.30-1.80) by decreasing IκBα expression due to the modulation of microRNA hsa-miR-449a but not hsa-miR-34b. Furthermore, both adverse genotypes exerted effect on increasing lung cancer risk in individuals with pre-existing COPD, while the -94del>insATTG did not in those without pre-existing COPD. However, no significant association with COPD or lung cancer was observed for -2966G>A and -826C>T. Our data suggested a common susceptible mechanism of inflammation in lung induced by genetic variants in NFκB1 (-94del>ins ATTG) or IκBα (2758G>A) to predict risk of COPD or lung cancer.

Increased neutrophil migration in smokers with or without chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVE

The number of airway neutrophils is increased in chronic obstructive pulmonary disease (COPD), and this may have a central pathophysiological role in the disease. In addition, activation of neutrophils increases their migration into sites of injury. We hypothesize that circulating neutrophils are activated in smokers.

METHODS

Peripheral blood neutrophils were isolated from healthy non-smokers (n = 15), and smokers with (n = 15) or without COPD (n = 15), who were matched with regard to cumulative tobacco exposure, and chemotactic responses to N-formyl-methionyl-leucyl-phenylalanine (fMLP), interleukin-8 (IL-8, CXCL8) and leukotriene B(4) (LTB(4)) were assessed using the ChemoTx System (Neuro Probe Inc., Gaithersburg, MD, USA). Serum tumour necrosis factor-α (TNF-α) concentrations were measured by ELISA. Surface expression of the neutrophil activation marker, CD11b, was measured by flow cytometry.

RESULTS

The chemotactic response to CXCL8 was increased in smokers with or without COPD (P < 0.05). Migration towards LTB(4) was increased in smokers without COPD compared with non-smokers (P < 0.05), whereas there was no difference in fMLP-induced chemotaxis between the groups. There was a correlation between serum TNF-α levels and migration induced by IL-8 (Rho = 0.442; P = 0.038) and LTB(4) (Rho = 0.428; P = 0.044) in the smokers. Furthermore, there was a tendency towards higher CD11b expression in the COPD group (P = 0.057).

CONCLUSIONS

Chemotaxis of circulating neutrophils towards CXCL8, and partly towards LTB(4), is increased in smokers, indicating a systemic influence of smoking on cell activation, irrespective of the presence of airflow limitation. The relationship between TNF-α and chemotactic response suggests that TNF-α is involved in neutrophil activation, resulting in enhanced migration.

Functional polymorphisms of Toll-like receptors 2 and 4 alter the risk for colorectal carcinoma in Europeans

BACKGROUND

Colon carcinogenesis is associated with increased expression levels of Toll-like receptor 2 and Toll-like receptor 4.

AIM

To determine in a Caucasian population the role of Toll-like receptor 2 and Toll-like receptor 4 polymorphisms in colorectal cancer development.

METHODS

Hospital based multicentre case control study involving 193 colorectal cancer patients and 278 healthy individuals. DNA samples were extracted from blood cells and genotyping of TLR2+597T>C, TLR2-4760T>C, TLR4-3745A>G, TLR2Arg753Gln, TLR4Asp299Gly was performed. Functionality of risk polymorphisms was evaluated through production of TNF-α in cell culture and Toll-like receptors levels quantified by real-time RT-PCR.

RESULTS

TLR2+597CC homozygous had 5-fold decreased risk (odds ratio (OR)=0.21, 95% CI: 0.09-0.50, p<0.001) and TLR4 299Gly homozygous 3-fold increased risk of colorectal cancer (OR=3.30, 95% CI: 1.18-9.28, p=0.015). In stratified analysis, TLR2+597CC genotype protective effect was even higher in overweight individuals (OR=0.17, 95% CI: 0.06-0.53, p<0.001) and in never smokers (OR=0.11, 95% CI: 0.02-0.51, p=0.001). Also, the increased risk effect for TLR4 299Gly homozygous genotype was higher in overweight individuals (OR=8.67, 95% CI: 1.11-87.85, p=0.011). TLR2+597T>C polymorphism conferred 41% less (p=0.03) and TLR4Asp299Gly 65% more TNF-α production (p=0.02) with no differences in Toll-like receptors levels.

CONCLUSION

Functional Toll-like receptor 2 and Toll-like receptor 4 polymorphisms significantly alter the risk to have colorectal cancer. Obesity and smoking may influence the risk for colorectal cancer in individuals presenting these genetic profiles.

Increased production of hydrogen peroxide by peripheral blood monocytes associated with smoking exposure intensity in smokers

BACKGROUND

Smoking is known to be associated with oxidative stress; however, it has not been elucidated whether the oxidative response is influenced by the intensity of smoking exposure.

OBJECTIVES

Evaluate the effect of smoking exposure on the secretion of hydrogen peroxide (H2O2) by the peripheral blood monocytes of smokers.

METHODS

A total of 25 smokers (50.3±8.8 years, 48% male) underwent the following evaluations: spirometry, pulse oximetry, body composition and total peripheral blood count. Peripheral blood monocyte (PBM) cultures were isolated and maintained, and IL-6 and TNF-α were measured in the plasma and in the supernatants of spontaneous and stimulated cultures. H2O2 was evaluated in the supernatants of the PBM cultures, and a subset of the PBM culture supernatants was stimulated with phorbol myristate acetate (PMA). We also evaluated 38 healthy controls (49.1±8.2 years, 42% male).

RESULTS

The spontaneous and stimulated monocytes' secretion of H2O2 were statistically higher in the smokers than in the healthy controls (p<0.001). The H2O2 secretions were statistically significant higher after stimulation with PMA in both groups (p<0.001). In the multiple regression analysis, we identified a positive, statistically significant association between pack-years of smoking and the spontaneous secretion of H2O2 by PBM culture, adjusted for potential confounding variables. The association between PBM culture secretion of H2O2 and the production of TNF-α and IL-6 was not significant.

CONCLUSION

We identified a positive association between higher production of H2O2 in smokers and higher smoking exposure during life. The influence of pack-years smoking may be a key modifiable factor in oxidative stress associated to smoking.

[Characteristics of stable chronic obstructive pulmonary disease related to systemic inflammation]

BACKGROUND AND OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is characterized by a systemic inflammation. The aim of this study was to evaluate the association between systemic inflammation, measured with C reactive protein (CRP), and clinical and functional outcomes of the disease.

PATIENTS AND METHODS

A randomized sample of 413 COPD patients from 31 primary health care centers of Barcelona was evaluated. Medical history, anthropometric measurements, toxic habits, treatments, Chronic Respiratory Questionnaire (CRQ) and dyspnea were registered. Spirometry, exhaled CO concentration and CRP in capillary blood were performed.

RESULTS

Median (standard deviation) of the age was 72 (8.4) years and forced expiratory volume in one second (FEV(1)) postbronchodilatador 1.65 (0.65) l. The correlation was negative between CRP and FEV(1) postbronchodilatador(r=-0.25, P<0.001) and between CRP and CRQ scores (r=-0.098, P=0.048) and positive between CRP and CO (r=0.1, P=0.039). The ratio of patients with elevated CRP was higher in advanced GOLD stage (P<0.001), worst dyspnea (P=0.042), patients treated with inhaled corticosteroids (P=0.018) and if they had been hospitalized during the last year (P=0.026). The multivariant analysis showed, as independent factors of elevated CRP, FEV(1) postbronchodilator and CO concentration.

CONCLUSION

In COPD patients, active smoking habit and the airway's obstruction degree are associated with a greater intensity of the inflammatory systemic response measured by the CRP.

TNF-α is associated with loss of lean body mass only in already cachectic COPD patients

Background

Systemic inflammation may contribute to cachexia in patients with chronic obstructive pulmonary disease (COPD). In this longitudinal study we assessed the association between circulating C-reactive protein (CRP), tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 levels and subsequent loss of fat free mass and fat mass in more than 400 COPD patients over three years.

Methods

The patients, aged 40–76, GOLD stage II-IV, were enrolled in 2006/07, and followed annually. Fat free mass and fat mass indexes (FFMI & FMI) were calculated using bioelectrical impedance, and CRP, TNF-α, IL-1ß, and IL-6 were measured using enzyme immunoassays. Associations with mean change in FFMI and FMI of the four inflammatory plasma markers, sex, age, smoking, FEV₁, inhaled steroids, arterial hypoxemia, and Charlson comorbidity score were analyzed with linear mixed models.

Results

At baseline, only CRP was significantly (but weakly) associated with FFMI (r = 0.18, p < 0.01) and FMI (r = 0.27, p < 0.01). Univariately, higher age, lower FEV₁, and use of beta2-agonists were the only significant predictors of decline in FFMI, whereas smoking, hypoxemia, Charlson score, and use of inhaled steroids predicted increased loss in FMI. Multivariately, high levels of TNF-α (but not CRP, IL-1ß or IL-6) significantly predicted loss of FFMI, however only in patients with established cachexia at entry.

Conclusion

This study does not support the hypothesis that systemic inflammation is the cause of accelerated loss of fat free mass in COPD patients, but suggests a role for TNF-α in already cachectic COPD patients.

[Tumor necrosis factor as an early marker of inflammation in healthy smokers]

BACKGROUND AND OBJECTIVES

Smoking creates an inflammation that leads to lose of lung function. Tumor necrosis factor alpha (TNF-α) is a cytokine that plays an important role in the pathogenesis of chronic obstructive pulmonary disease. There is a need to develop methods for an early detection of an impaired lung function in smokers. We aimed to show that smokers have higher levels of TNF-α in serum and exhaled breath condensate (EBC). We also analysed the influence of sex, age and weight on TNF-α, and determined the association between smoking, pulmonary function and TNF-α.

PATIENTS AND METHODS

Prospective study of smokers and non-smokers without any known disease. Respiratory function tests, EBC and blood samples were performed before smoking cessation.

STATISTICAL ANALYSIS

SPSS 11.0.

RESULTS

Fifty-one patients (60.8% smokers), 56.9% females, mean age 39.88 years old. Smokers initiated at an age of 15.77 years; the mean of cigarettes/day was 21.68. Significant differences in TNF-α serum levels between smokers and non-smokers were observed (P<.043). Differences did not reach significance for EBC. For tobacco consumption data, only age at smoking initiation and serum TNF-α levels had a correlation. A significant relation between TNF-α serum levels and forced expiratory volume in one second and forced vital capacity was found.

CONCLUSIONS

Smokers show higher TNF-α levels in serum. Number of years of smoking has an influence on TNF-α levels. There is a modest correlation between pulmonary function and plasma TNF-α levels, but not for EBC.

Role of CXCL5 in leukocyte recruitment to the lungs during secondhand smoke exposure

Chronic obstructive pulmonary disease (COPD) is the third leading cause of mortality in the United States. The major cause of COPD is cigarette smoking. Extensive leukocyte influx into the lungs, mediated by chemokines, is a critical event leading to COPD. Although both resident and myeloid cells secrete chemokines in response to inflammatory stimuli, little is known about the role of epithelial-derived chemokines, such as CXC chemokine ligand (CXCL)5, in the pathogenesis of cigarette smoke-induced inflammation. To explore the role of CXCL5, we generated CXCL5 gene-deficient mice and exposed them to secondhand smoke (SHS) for 5 hours/day for 5 days/week up to 3 weeks (subacute exposure). We observed a reduced recruitment of leukocytes to the lungs of CXCL5(-/-) mice compared with their wild-type (WT) counterparts, and noted that macrophages comprised the predominant leukocytes recruited to the lungs. Irradiation experiments performed on CXCL5(-/-) or WT mice transplanted with WT or CXCL5(-/-) bone marrow revealed that resident but not hematopoietic cell-driven CXCL5 is important for mediating SHS-induced lung inflammation. Interestingly, we observed a significant reduction of monocyte chemotactic protein-1 (MCP-1/CC chemokine ligand 2) concentrations in the lungs of CXCL5(-/-) mice. The instillation of recombinant MCP-1 in CXCL5(-/-) mice reversed macrophage recruitment. Our results also show the reduced activation of NF-κB/p65 in the lungs, as well as the attenuated activation of C-Jun N-terminal kinase, p42/44, and p38 mitogen-activated protein kinases and the expression of intercellular adhesion molecule-1 in the lungs of SHS-exposed CXCL5(-/-) mice. Our findings suggest an important role for CXCL5 in augmenting leukocyte recruitment in SHS-induced lung inflammation, and provide novel insights into CXCL5-driven pathogenesis.

Is age-related decline in lean mass and physical function accelerated by obstructive lung disease or smoking?

BACKGROUND

and aims Cross-sectional studies suggest that obstructive lung disease (OLD) and smoking affect lean mass and mobility. A study was undertaken to investigate whether OLD and smoking accelerate the ageing-related decline in lean mass and physical functioning.

METHODS

260 patients with OLD (mean±SD forced expiratory volume in 1 s (FEV1) 63±18% predicted), 157 smoking controls (FEV(1) 95±16% predicted), 866 former-smoking controls (FEV1 100±16% predicted) and 891 never-smoking controls (FEV1 104±17% predicted) participating in the Health, Aging and Body Composition (ABC) Study were studied. At baseline the mean age was 74±3 years and participants reported no functional limitations. Baseline and 7-year longitudinal data of body composition (by dual-energy x-ray absorptiometry), muscle strength (by hand and leg dynamometry) and Short Physical Performance Battery (SPPB) were investigated.

RESULTS

Compared with never-smoking controls, patients with OLD and smoking controls had a significantly lower weight, fat mass, lean mass and bone mineral content (BMC) at baseline (p<0.05). While the loss of weight, fat mass, lean mass and strength was comparable between patients with OLD and never-smoking controls, the SPPB declined 0.12 points/year faster in men with OLD (p=0.01) and BMC declined 4 g/year faster in women with OLD (p=0.02). In smoking controls only lean mass declined 0.1 kg/year faster in women (p=0.03) and BMC 8 g/year faster in men (p=0.02) compared with never-smoking controls.

CONCLUSIONS

Initially well-functioning older adults with mild-to-moderate OLD and smokers without OLD have a comparable compromised baseline profile of body composition and physical functioning, while 7-year longitudinal trajectories are to a large extent comparable to those observed in never-smokers without OLD. This suggests a common insult earlier in life related to smoking.

Systemic inflammation in COPD in relation to smoking status

BACKGROUND AND AIMS

Smoking is the main risk factor for the development of chronic obstructive pulmonary disease (COPD) that has been recently defined as a systemic pulmonary inflammatory disease. However, the impact of smoking itself on systemic inflammation in COPD patients has not yet been well established. The aim of our study was to investigate the association between inflammatory markers and smoking status.

MATERIALS AND METHODS

We compared 202 current smokers, 61 ex-smokers and 57 never-smokers, all COPD patients. Assessments included medical history, spirometry, alpha-1 antitrypsin (AAT) genotyping, serum AAT, C-reactive protein (CRP), tumor necrosis factor (TNF)-α, and soluble tumor necrosis factor receptor (sTNFR)-1 and sTNFR-2 concentrations.

RESULTS

AAT and CRP concentrations in smokers (1.75 ± 0.51 g/L and 14.4 [9.5-20.5] mg/L) and ex-smokers (1.69 ± 0.43 g/L and 12.3 [8.7-16.3] mg/L) were higher than in never-smokers (1.49 ± 0.38 g/L and 5.1 [2.5-8.7] mg/L; p < 0.05). sTNFR-1 level was higher in smokers than ex-smokers or never-smokers (241.2 pg/mL [145.3-349.4] vs. 213.7 pg/mL [147.1-280.3] and 205.2 pg/mL [125-275]; p < 0.05).

CONCLUSIONS

Our data confirm that smoking is associated with increased levels of AAT, CRP, and sTNFR-1 in COPD patients, an array of systemic inflammation markers that continue to be active even after smoking cessation.

Green tea catechins improve human forearm vascular function and have potent anti-inflammatory and anti-apoptotic effects in smokers

OBJECTIVE

Several epidemiological investigations have reported that green tea reduces cardiovascular and cerebral vascular risks. Green tea catechins may improve peripheral endothelial dysfunction in smokers. The purpose of this study was to elucidate the beneficial effect of green tea catechins on the repair of endothelial dysfunction in smokers.

METHODS

Thirty healthy male smokers divided into three groups ingested a green tea beverage containing 0 mg (control group), 80 mg (middle dose group) or 580 mg (high dose group) of green tea catechins (GTC) daily for two weeks, and endothelial-dependent vasodilatation was investigated by measuring forearm blood flow (FBF) response to reactive hyperemia (RH) by venous occlusion strain-gauge plethysmography.

RESULTS

An acute effect was that the FBF response to RH significantly increased 2 hr after GTC intake in the high dose group. However, no increase was observed in the other groups. The chronic administration of GTC for one or two weeks ameliorated the FBF responses to RH in the high dose group. On the other hand, no significant increase was observed in the FBF responses to RH in the other groups. Moreover, the plasma concentration of 8-OHdG, IL-6, TNF-alpha, and soluble Fas decreased significantly for two weeks in the high dose group, however, the level of IL-1 beta remained unchanged over this period.

CONCLUSION

Green tea consumption over short and long periods appears to ameliorate endothelial dysfunction by scavenging free radicals with anti-inflammatory and anti-apoptotic properties in healthy male smokers.