Airway and systemic inflammation and decline in lung function in patients with COPD

Evaluation of von Willebrand factor in COPD patients

OBJECTIVE

To compare the absolute serum von Willebrand factor (vWF) levels and relative serum vWF activity in patients with clinically stable COPD, smokers without airway obstruction, and healthy never-smokers.

METHODS

The study included 57 subjects, in three groups: COPD (n = 36); smoker (n = 12); and control (n = 9). During the selection phase, all participants underwent chest X-rays, spirometry, and blood testing. Absolute serum vWF levels and relative serum vWF activity were obtained by turbidimetry and ELISA, respectively. The modified Medical Research Council scale (cut-off score = 2) was used in order to classify COPD patients as symptomatic or mildly symptomatic/asymptomatic.

RESULTS

Absolute vWF levels were significantly lower in the control group than in the smoker and COPD groups: 989 ± 436 pg/mL vs. 2,220 ± 746 pg/mL (p < 0.001) and 1,865 ± 592 pg/mL (p < 0.01). Relative serum vWF activity was significantly higher in the COPD group than in the smoker group (136.7 ± 46.0% vs. 92.8 ± 34.0%; p < 0.05), as well as being significantly higher in the symptomatic COPD subgroup than in the mildly symptomatic/asymptomatic COPD subgroup (154 ± 48% vs. 119 ± 8%; p < 0.05). In all three groups, there was a negative correlation between FEV1 (% of predicted) and relative serum vWF activity (r2 = -0.13; p = 0.009).

CONCLUSIONS

Our results suggest that increases in vWF levels and activity contribute to the persistence of systemic inflammation, as well as increasing cardiovascular risk, in COPD patients.

Extreme values of hemoglobin a1c are associated with increased risks of chronic obstructive pulmonary disease in patients with type 2 diabetes: a competing risk analysis in national cohort of Taiwan diabetes study

The purpose of this study was to evaluate the relationship between glycated hemoglobin (HbA1c) and chronic obstructive pulmonary disease (COPD) in patients with type 2 diabetes.We conducted a retrospective cohort study involving 45,753 patients with type 2 diabetes, who participated in the National Diabetes Case Management Program in Taiwan. HbA1c at baseline and COPD events over the subsequent years were analyzed.After multivariate adjustment, the COPD risk increased among patients with HbA1c levels <6.0%, compared with that in patients with HbA1c levels ranging from 6.0% to 7.0% (hazard ratio: 1.19, 95% confidence interval (CI): 1.06-1.34). Similarly, high HbA1c levels (≥10%) were independently associated with COPD (1.19, 95% CI: 1.06-1.32). A U-shaped relationship was observed between HbA1c levels and COPD incidence.HbA1c levels lower than 6.0% and higher than 10% are associated with an increased risk of COPD in patients with type 2 diabetes. These findings suggest that meeting the recommended HbA1c targets might reduce the risk of COPD, but care should be taken not to pose risks to this population.

Characterisation of the frequent exacerbator phenotype in COPD patients in a large UK primary care population

BACKGROUND

The 'frequent exacerbator' is recognised as an important phenotype in COPD. Current understanding about this phenotype comes from prospective longitudinal clinical trials in secondary/tertiary care with little information reported in primary care populations.

AIMS

To characterize the frequent-exacerbator phenotype and identify associated risk factors in a large UK primary care COPD population.

METHODS

Using a large database of primary care patients from 80 UK general practices, patients were categorised using GOLD 2014 criteria into high and low risk groups based on exacerbation history. A multivariate logistic regression model was used to investigate covariates associated with the frequent-exacerbator phenotype and risk of experiencing a severe exacerbation (leading to hospitalisation).

RESULTS

Of the total study population (n = 9219), 2612 (28%) fulfilled the criteria for high risk frequent-exacerbators. Independent risk factors (adjusted odds ratio [95% CI]) for ≥2 exacerbations were: most severely impaired modified Medical Research Council (mMRC) dyspnoea score (mMRC grade 4: 4.37 [2.64-7.23]), lower FEV1 percent predicted (FEV1 <30%: 2.42 [1.61-3.65]), co-morbid cardiovascular disease (1.42 [1.19-1.68]), depression (1.56 [1.22-1.99]) or osteoporosis (1.54 [1.19-2.01]), and female gender (1.20 [1.01-1.43]). Older patients (≥75 years), those with most severe lung impairment (FEV1 <30%), those with highest mMRC score and those with co-morbid osteoporosis were identified as most at risk of experiencing exacerbations requiring hospitalisation.

CONCLUSIONS

Although COPD exacerbations occur across all grades of disease severity, female patients with high dyspnoea scores, more severely impaired lung function and co-morbidities are at greatest risk. Elderly patients, with severely impaired lung function, high mMRC scores and osteoporosis are associated with experience of severe exacerbations requiring hospitalisation.

Risk factors for acute exacerbations of COPD in a primary care population: a retrospective observational cohort study

OBJECTIVES

To evaluate risk factors associated with exacerbation frequency in primary care. Information on exacerbations of chronic obstructive pulmonary disease (COPD) has mainly been generated by secondary care-based clinical cohorts.

DESIGN

Retrospective observational cohort study.

SETTING

Electronic medical records database (England and Wales).

PARTICIPANTS

58,589 patients with COPD aged ≥40 years with COPD diagnosis recorded between 1 April 2009 and 30 September 2012, and with at least 365 days of follow-up before and after the COPD diagnosis, were identified in the Clinical Practice Research Datalink. Mean age: 69 years; 47% female; mean forced expiratory volume in 1s 60% predicted.

OUTCOME MEASURES

Data on moderate or severe exacerbation episodes defined by diagnosis and/or medication codes 12 months following cohort entry were retrieved, together with demographic and clinical characteristics. Associations between patient characteristics and odds of having none versus one, none versus frequent (≥2) and one versus frequent exacerbations over 12 months follow-up were evaluated using multivariate logistic regression models.

RESULTS

During follow-up, 23% of patients had evidence of frequent moderate-to-severe COPD exacerbations (24% one; 53% none). Independent predictors of increased odds of having exacerbations during the follow-up, either frequent episodes or one episode, included prior exacerbations, increasing dyspnoea score, increasing grade of airflow limitation, females and prior or current history of several comorbidities (eg, asthma, depression, anxiety, heart failure and cancer).

CONCLUSIONS

Primary care-managed patients with COPD at the highest risk of exacerbations can be identified by exploring medical history for the presence of prior exacerbations, greater COPD disease severity and co-occurrence of other medical conditions.

Diagnostic morphology: biophysical indicators for iron-driven inflammatory diseases

Most non-communicable diseases involve inflammatory changes in one or more vascular systems, and there is considerable evidence that unliganded iron plays major roles in this. Most studies concentrate on biochemical changes, but there are important biophysical correlates. Here we summarize recent microscopy-based observations to the effect that iron can have major effects on erythrocyte morphology, on erythrocyte deformability and on both fibrinogen polymerization and the consequent structure of the fibrin clots formed, each of which contributes significantly and negatively to such diseases. We highlight in particular type 2 diabetes mellitus, ischemic thrombotic stroke, systemic lupus erythematosus, hereditary hemochromatosis and Alzheimer's disease, while recognizing that many other diseases have co-morbidities (and similar causes). Inflammatory biomarkers such as ferritin and fibrinogen are themselves inflammatory, creating a positive feedback that exacerbates disease progression. The biophysical correlates we describe may provide novel, inexpensive and useful biomarkers of the therapeutic benefits of successful treatments.

Surfactant protein D, Club cell protein 16, Pulmonary and activation-regulated chemokine, C-reactive protein, and Fibrinogen biomarker variation in chronic obstructive lung disease

Chronic obstructive pulmonary disease (COPD) is a multifaceted condition that cannot be fully described by the severity of airway obstruction. The limitations of spirometry and clinical history have prompted researchers to investigate a multitude of surrogate biomarkers of disease for the assessment of patients, prediction of risk, and guidance of treatment. The aim of this review is to provide a comprehensive summary of observations for a selection of recently investigated pulmonary inflammatory biomarkers (Surfactant protein D (SP-D), Club cell protein 16 (CC-16), and Pulmonary and activation-regulated chemokine (PARC/CCL-18)) and systemic inflammatory biomarkers (C-reactive protein (CRP) and fibrinogen) with COPD. The relevance of these biomarkers for COPD is discussed in terms of their biological plausibility, their independent association to disease and hard clinical outcomes, their modification by interventions, and whether changes in clinical outcomes are reflected by changes in the biomarker.

Neutrophil-to-lymphocyte ratio in chronic obstructive pulmonary disease: a retrospective study

Chronic obstructive pulmonary disease (COPD) is a common chronic inflammatory disease of the lung with a high mortality and morbidity rate. Some of the inflammatory markers such as C-reactive protein (CRP), leukocyte count are associated with COPD. In this study, we aimed to evaluate the role of neutrophil-to-lymphocyte ratio (NLR) in COPD patients comparing with the other well-known inflammatory markers. We retrospectively enrolled the laboratory results of 269 COPD patients of which 178 patients at stable period and 91 patients during acute exacerbation and 50 sex- and age- matched healthy controls. We found that NLR values of the stable COPD patients were significantly higher than those of the controls (P < 0.001). During acute exacerbation of the disease there was a further increase compared to stable period (P < 0.001). NLR values were also positively correlated with serum CRP levels and red cell distribution width (RDW) and negatively correlated with mean platelet volume (MPV) in both COPD groups. In conclusion, NLR could be considered as a new inflammatory marker for assessment of inflammation in COPD patients with its quick, cheap, easily measurable property with routine complete blood count analysis.

A prospective study on bacterial and atypical etiology of acute exacerbation in chronic obstructive pulmonary disease

ABSTRACT 

Aim: The bacterial and atypical etiology of acute exacerbations of chronic obstructive pulmonary disease was investigated and the diagnostic techniques used were compared among 92 hospitalized patients. Materials & methods: Sputum specimens were investigated using culture and PCR, serological status evaluation was performed and the inflammatory profile was associated with the microbiological results. Results & conclusion: The majority of the patients (65.2%) had very severe airway obstruction. The most common bacteria were Haemophilus influenzae and Pseudomonas aeruginosa (23.9 and 14.1%, respectively). Acinetobacter baumannii- and P. aeruginosa-positive cultures were associated with prolonged hospitalization and severe airway obstruction (p = 0.03 and 0.031, respectively). Chlamydia pneumoniae or Mycoplasma pneumoniae infection was diagnosed in four and two patients, respectively. Discrepant results were detected between PCR and serology, especially regarding C. pneumoniae.

Lower airway colonization and inflammatory response in COPD: a focus on Haemophilus influenzae

Bacterial infection of the lower respiratory tract in chronic obstructive pulmonary disease (COPD) patients is common both in stable patients and during acute exacerbations. The most frequent bacteria detected in COPD patients is Haemophilus influenzae, and it appears this organism is uniquely adapted to exploit immune deficiencies associated with COPD and to establish persistent infection in the lower respiratory tract. The presence of bacteria in the lower respiratory tract in stable COPD is termed colonization; however, there is increasing evidence that this is not an innocuous phenomenon but is associated with airway inflammation, increased symptoms, and increased risk for exacerbations. In this review, we discuss host immunity that offers protection against H. influenzae and how disturbance of these mechanisms, combined with pathogen mechanisms of immune evasion, promote persistence of H. influenzae in the lower airways in COPD. In addition, we examine the role of H. influenzae in COPD exacerbations, as well as interactions between H. influenzae and respiratory virus infections, and review the role of treatments and their effect on COPD outcomes. This review focuses predominantly on data derived from human studies but will refer to animal studies where they contribute to understanding the disease in humans.

The mediating role of cytokine IL-6 on the relationship of FEV₁ upon 6-minute walk distance in chronic obstructive pulmonary disease

Objectives

To explore the mediating role of protein interleukin-6 (IL-6) on the relationship between forced expiratory volume in 1 second (FEV₁) and 6-minute walk distance (6MWD) and, further, to determine whether status variables (such as age, sex, and body mass index [BMI]) operate as moderators of this mediation relationship.

Design

Moderated mediation model.

Setting

An inpatient pulmonary rehabilitation center in Italy.

Participants

All 153 patients involved in the screening of a randomized controlled clinical trial (ClinicalTrials.gov identifier: NCT01253941) were included in this study. All patients were Global initiative for chronic Obstructive Lung Disease (GOLD) stages I–IV and were aged 70.1±9.1 years.

Measurements

At run-in phase of the protocol, clinical and functional screening included BMI, fasting plasma levels of protein (IL-6), spirometry, and standardized 6-minute walking test, measured at the start of the respiratory rehabilitation program.

Methods

The size of the indirect effect of the initial variable (FEV₁) upon the outcome variable (6MWD) through the intervening variable (IL-6) was computed and tested for statistical significance. Moderated mediation analyses were subsequently conducted with age, sex, and BMI.

Results

FEV₁ averaged 53.4%±21.2%, and 6MWD 66.4%±41.3% of predicted. Median protein IL-6 was 6.68 pg/mL (interquartile range: 5.96). A bootstrapped mediation test supported the predicted indirect pathway (P=0.003). The indirect effect through IL-6 log units accounted for 17% of the total effect between FEV₁ and 6MWD. Age functioned as a significant moderator of the mediational pattern. For individuals aged <70 years, the standardized indirect effect was significant (0.122, 95% confidence interval [CI]: 0.044–0.254, P=0.004), and for individuals >70 years it was not significant (0.04, 95% CI: –0.010 to 0.142, P=0.10).

Conclusion

This moderated mediation result based on concurrent data suggests, but does not prove, a causal role of systemic inflammatory syndrome on progression from functional impairment to “frailty” status and substantial disability in aging chronic obstructive pulmonary disease.

Ion flux in the lung: virus-induced inflammasome activation

Innate immunity has a primary role in lung antimicrobial defenses. The inflammasome has evolved for this purpose and is an important surveillance system that, when triggered, fights infection and eliminates pathogens. However, there is growing evidence that the inflammasome also plays a role in the pathogenesis of acute and chronic respiratory disease. Inflammasomes contribute to both the clearance of the pathogen as well as its pathogenesis - depending on the amount of inflammation triggered. How respiratory viruses trigger inflammasome activation remains unclear. Emerging evidence shows that ion flux is responsible for triggering inflammasome activation in the lung, causing lung pathology and disease exacerbations. Viroporins, encoded by all common respiratory viruses, are responsible for the changes in intracellular ion homeostasis that modulate inflammasome activation. This is a novel mechanism by which respiratory viral infection activates inflammasomes, and identifies sensing of disturbances in intracellular ionic concentrations as a novel pathogen-recognition pathway in the lung.

Lung function abnormalities in HIV-infected adults and children

Despite the advent of antiretroviral therapy (ART), the human immunodeficiency virus (HIV) epidemic remains a global health crisis with a high burden of respiratory disease among infected persons. While the early complications of the epidemic were dominated by opportunistic infections, improved survival has led to the emergence of non-infectious conditions that are associated with chronic respiratory symptoms and pulmonary disability. Obstructive ventilatory defects and reduced diffusing capacity are common findings in adults, and the association between HIV and chronic obstructive pulmonary disease is increasingly recognized. There is synergism between viral factors, opportunistic infections, conventional influences like tobacco smoke and biomass fuel exposure, and potentially, the immunological effects of ART on the development of HIV-associated chronic obstructive lung disease. Pulmonary function data for HIV-infected infants and children are scarce, but shows that bronchiectasis and obliterative bronchiolitis with severe airflow limitation are major problems, particularly in the developing world. However, studies from these regions are sorely lacking. There is thus a major unmet need to understand the influences of chronic HIV infection on the lung in both adults and children, and to devise strategies to manage and prevent these diseases in HIV-infected individuals. It is important for clinicians working with HIV-infected individuals to have an appreciation of their effects on measurements of lung function. This review therefore summarizes the lung function abnormalities described in HIV-positive adults and children, with an emphasis on obstructive lung disease, and examines potential pathogenic links between HIV and the development of chronic pulmonary disability.

Cigarette smoke primes the pulmonary environment to IL-1α/CXCR-2-dependent nontypeable Haemophilus influenzae-exacerbated neutrophilia in mice

Cigarette smoke has a broad impact on the mucosal environment with the ability to alter host defense mechanisms. Within the context of a bacterial infection, this altered host response is often accompanied by exacerbated cellular inflammation, characterized by increased neutrophilia. The current study investigated the mechanisms of neutrophil recruitment in a murine model of cigarette smoke exposure and, subsequently, a model of both cigarette smoke exposure and bacterial infection. We investigated the role of IL-1 signaling in neutrophil recruitment and found that cigarette smoke-induced neutrophilia was dependent on IL-1α produced by alveolar macrophages. In addition to being the crucial source of IL-1α, alveolar macrophages isolated from smoke-exposed mice were primed for excessive IL-1α production in response to bacterial ligands. To test the relevance of exaggerated IL-1α production in neutrophil recruitment, a model of cigarette smoke exposure and nontypeable Haemophilus influenzae infection was developed. Mice exposed to cigarette smoke elaborated an exacerbated CXCR2-dependent neutrophilia in response to nontypeable Haemophilus influenzae. Exacerbated neutrophilia was dependent on IL-1α priming of the pulmonary environment by cigarette smoke as exaggerated neutrophilia was dependent on IL-1 signaling. These data characterize a novel mechanism of cigarette smoke priming the lung mucosa toward greater IL-1-driven neutrophilic responses to bacteria, with a central role for the alveolar macrophage in this process.

Increased levels of soluble interleukin-6 receptor and CCL3 in COPD sputum

Background

COPD patients have increased numbers of macrophages and neutrophils in the lungs. Interleukin-6 (IL-6) trans-signaling via its soluble receptor sIL-6R, governs the influx of innate immune cells to inflammatory foci through regulation of the chemokine CCL3. We hypothesized that there would be enhanced levels of IL-6, sIL-6R and CCL3 in COPD sputum.

Methods

59 COPD patients, 15 HNS and 15 S underwent sputum induction and processing with phosphate buffered saline to obtain supernatants for IL-6, sIL-6R and CCL3 analysis. Cytoslides were produced for differential cell counting and immunocytochemistry (COPD; n = 3) to determine cell type surface expression of the CCL3 receptors CCR5 and CCR1.

Results

COPD patients expressed higher levels (p < 0.05) of sIL-6R and CCL3 compared to controls (sIL-6R medians pg/ml: COPD 166.4 vs S 101.1 vs HNS 96.4; CCL3 medians pg/ml: COPD 117.9 vs S 0 vs HNS 2.7). COPD sIL-6R levels were significantly correlated with sputum neutrophil (r = 0.5, p < 0.0001) and macrophage (r = 0.3, p = 0.01) counts. Immunocytochemical analysis revealed that CCR5 and CCR1 were exclusively expressed on airway macrophages.

Conclusion

Enhanced airway generation of sIL-6R may promote IL-6 trans-signaling in COPD. Associated upregulation of CCL3 may facilitate the recruitment of macrophages into the airways by ligation of CCR1 and CCR5.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-014-0103-4) contains supplementary material, which is available to authorized users.

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

Background

The role of interleukins in the severity and clinical profile of chronic obstructive pulmonary disease (COPD) is not known, but evidence supports the contribution of systemic inflammation to disease pathophysiology. This study evaluated the relationship of serum biomarkers to the severity and clinical parameters of COPD.

Methods and findings

Serum levels of high-sensitivity C-reactive protein, interleukin-6 (IL-6), and interleukin-8 (IL-8) were measured in 50 patients with stable COPD and in 16 controls. The levels of these biomarkers were compared with parameters of severity, such as the grading of flow obstruction using the recommendations of the Global initiative for chronic Obstructive Lung Disease, the BMI (body mass index), obstruction, dyspnea, exercise capacity (health index) index, the number of exacerbations within the last year, and peripheral oxygen saturation after the six-minute walk test, and with clinical parameters, such as bronchitis and non-bronchitis phenotypes, the number of associated comorbidities, and the smoking burden. COPD patients exhibited higher levels of IL-6 and IL-8 compared to the control group. Higher levels of IL-6 occurred in COPD groups with body mass index <21 kg/m², with more than two exacerbations in the past year, with a higher smoking burden, and with bronchitis. The increase in serum IL-8 was found only in the group with the highest number of exacerbations within the previous year.

Conclusion

Increased IL-6 was mainly associated with smoking burden, in patients who had smoked for more than 30 pack-years and exhibited a bronchitis phenotype. No direct association was observed for both IL-6 and IL-8 blood levels with the severity of COPD in ex-smokers.

Daily activity during stability and exacerbation of chronic obstructive pulmonary disease

Background

During most COPD exacerbations, patients continue to live in the community but there is little information on changes in activity during exacerbations due to the difficulties of obtaining recent, prospective baseline data.

Methods

Patients recorded on daily diary cards any worsening in respiratory symptoms, peak expiratory flow (PEF) and the number of steps taken per day measured with a Yamax Digi-walker pedometer. Exacerbations were defined by increased respiratory symptoms and the number of exacerbations experienced in the 12 months preceding the recording of daily step count used to divide patients into frequent (> = 2/year) or infrequent exacerbators.

Results

The 73 COPD patients (88% male) had a mean (±SD) age 71(±8) years and FEV₁ 53(±16)% predicted. They recorded pedometer data on a median 198 days (IQR 134–353). At exacerbation onset, symptom count rose by 1.9(±1.3) and PEF fell by 7(±13) l/min. Mean daily step count fell from 4154(±2586) steps/day during a preceding baseline week to 3673(±2258) step/day during the initial 7 days of exacerbation (p = 0.045). Patients with larger falls in activity at exacerbation took longer to recover to stable level (rho = −0.56; p < 0.001). Recovery in daily step count was faster (median 3.5 days) than for exacerbation symptoms (median 11 days; p < 0.001). Recovery in step count was also faster in untreated compared to treated exacerbation (p = 0.030).

Daily step count fell faster over time in the 40 frequent exacerbators, by 708 steps/year, compared to 338 steps/year in 33 infrequent exacerbators (p = 0.002).

Conclusions

COPD exacerbations reduced physical activity and frequent exacerbations accelerate decline in activity over time.

Differential expression of C-reactive protein and serum amyloid A in different cell types in the lung tissue of chronic obstructive pulmonary disease patients

BACKGROUND

Chronic systemic inflammatory syndrome has been implicated in the pathobiology of extrapulmonary manifestations of chronic obstructive pulmonary disease (COPD). We aimed to investigate which cell types within lung tissue are responsible for expressing major acute-phase reactants in COPD patients and disease-free ("resistant") smokers.

METHODS

An observational case-control study was performed to investigate three different cell types in surgical lung samples of COPD patients and resistant smokers via expression of the C-reactive protein (CRP) and serum amyloid A (SAA1, SAA2 and SAA4) genes. Epithelial cells, macrophages and fibroblasts from the lung parenchyma were separated by magnetic microbeads (CD326, CD14 and anti-fibroblast), and gene expression was evaluated by RT-PCR.

RESULTS

The sample consisted of 74 subjects, including 40 COPD patients and 34 smokers without disease. All three cell types were capable of synthesizing these biomarkers to some extent. In fibroblasts, gene expression analysis of the studied biomarkers demonstrated increased SAA2 and decreased SAA1 in patients with COPD. In epithelial cells, there was a marked increase in CRP, which was not observed in fibroblasts or macrophages. In macrophages, however, gene expression of these markers was decreased in COPD patients compared to controls.

CONCLUSIONS

These results provide novel information regarding the gene expression of CRP and SAA in different cell types in the lung parenchyma. This study revealed differences in the expression of these markers according to cell type and disease status and contributes to the identification of cell types that are responsible for the secretion of these molecules.

Plasma cytokine profiles related to smoking-sensitivity and phenotypes of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) develops only in smoking-sensitive smokers and manifests heterogeneous phenotypes, including emphysema and non-emphysema types. We aimed to identify biomarkers related to the smoking-sensitivity and phenotypes of COPD. Among 240 smokers suggestive of COPD, we studied on four groups defined by % forced expiratory volume in one second (FEV1) and computed tomography-based pulmonary emphysema. Plasma concentrations of 33 inflammatory markers were measured in four groups as well as Non-smokers using multiplex protein arrays. IL-5, IL-7 and IL-13 were identified to be associated with smoking sensitivity and IL-6 and IL-10 were candidate biomarkers for airway-lesion dominant COPD.

C-reactive protein and lung diseases

C-reactive protein (CRP), a member of the pentraxin family of plasma proteins, is one of the most distinctive acute phase reactants. In response to inflammation, cell damage or tissue injury, plasma level of CRP rapidly and dramatically increases up to 1000-fold, a phenomenon that has been used for years to monitor infections and many destructive/inflammatory conditions. The magnitude of CRP increase usually correlates with the severity of injury or inflammation and reflects an important physiological role of this interesting but still under-investigated protein. It is now generally accepted that CRP is involved in host defense and inflammation. However, the exact function of this protein in health and disease remains unclear. Many studies have demonstrated that in different pathophysiological conditions CRP might be involved in the regulation of lung function and may participate in the pathogenesis of various pulmonary disorders. The fluctuation of CRP concentrations in both alveolar fluid and serum associated with different pulmonary diseases suggests its important role in lung biology. Discussion of the still controversial functions of CRP in lung physiology and diseases is the main focus of this review.

Predictors of exacerbation frequency in chronic obstructive pulmonary disease

Background

Exacerbations of chronic obstructive pulmonary disease (COPD) are sporadic, acute worsening of symptoms. Identifying predictors of exacerbation frequency may facilitate medical interventions that reduce exacerbation frequency and severity. The objective of this study was to determine predictors of exacerbation frequency and mortality.

Methods

A total of 227 COPD patients were enrolled in a prospective clinical study between January 2000 and December 2011. Reported exacerbations were recorded for the year preceding enrollment and annually thereafter, and patients were grouped by median annual exacerbation frequency into those experiencing infrequent exacerbations (less than one exacerbation annually) and frequent exacerbations (one or more exacerbation annually). Patients experiencing frequent exacerbations were further divided into those experiencing moderately frequent exacerbations (fewer than two exacerbations per year) and severely frequent exacerbations (two or more exacerbations per year). The rate of clinical relapse and survival was recorded over a 10-year period. The mean of follow-up time was 5.15 years per patient.

Results

For patients experiencing infrequent, moderately frequent, and severely frequent exacerbations, median exacerbations in the year preceding enrollment were 0.0, 0.5, 1.0, respectively, and more frequent exacerbations correlated with lower baseline forced expiratory volume in one second (FEV₁) (0.81 L, 0.75 L, and 0.66 L, respectively), higher comorbidity (70.7%, 75.0%, and 89.4%, respectively), and greater NPPV use during hospitalization (16.4%, 35.9% and 51.1%, respectively). FEV₁ declined and mortality increased with increasing exacerbation frequency.

Conclusions

Exacerbation frequency can be used to generate discreet patient subpopulations, supporting the hypothesis that multiple COPD phenotypes exist and can be used in patient risk stratification.

Two different dosages of nebulized steroid versus parenteral steroid in the management of COPD exacerbations: a randomized control trial

BACKGROUND

The study aimed to compare the efficacy and safety of nebulized steroid (NS) with systemic corticosteroids (SC) and to determine optimal NS dose in the treatment of patients with COPD exacerbations requiring hospitalization.

MATERIAL AND METHODS

The study was a randomized, parallel design trial. Eligible patients (n=86) were randomly allocated to 1 of the 3 treatment groups: parenteral corticosteroid (PS) (n=33), 4 mg (NB) (n=27), or 8 mg NB (n=26). Partial pressure of arterial oxygen (PaO2), carbon dioxide (PaCO2), pH, and oxygen saturation (SaO2) were evaluated at baseline, 24 h, 48 h, and discharge. Airway obstruction (forced vital capacity [FVC] and forced expiratory volume 1 s [FEV1]) was evaluated at admission and discharge.

RESULTS

There were no significant differences between the groups for all parameters at all time periods, except for higher FEV1 value in the 8-mg NB group at baseline. In groups, significant differences were determined for FVC, FEV1, PaO2, and SaO2 (p<0.001), but not for PaCO2 and pH, in comparison to their baseline values. As adverse events, hyperglycemia and oral moniliasis were observed in the PS group (n=4) and in the NB groups (n=5), respectively, and treatment change was required in 9 patients (2 patients in the PS group and 7 patients in the NB groups) (p=0.57).

CONCLUSIONS

Nebulized budesonide may be used as an alternative to SC because of its equal effectiveness and lesser systemic adverse effects. The choice of optimal dosage needs to be evaluated carefully because adverse effect and dropout rates varied according to dosage. However, there is a need for further studies including more severe cases and evaluating long-term outcomes or relapses comparing the 3 arms.

Time course of inflammation resolution in patients with frequent exacerbations of chronic obstructive pulmonary disease

BACKGROUND

When exacerbation of chronic obstructive pulmonary disease (AECOPD) occurs frequently, patients have high levels of airway and systemic inflammation and a poor quality of life. This study compared the nature and course of systemic and airway inflammation during AECOPD between patients who experienced frequent exacerbations and those with non-frequent exacerbations.

MATERIAL AND METHODS

Consecutive hospitalized patients with AECOPD were recruited and divided into 2 groups according to the frequency of AECOPD they had experienced in the previous year. Frequent exacerbators (defined as 2 or more AECOPD in the previous year) and non-frequent exacerbators (defined as zero or 1 AECOPD in the previous year). Inflammatory (interleukin 6, interleukin 8, myeloperoxidase, and C-reactive protein) and clinical (dyspnea, COPD assessment test (CAT), and peak expiratory flow) indices were assessed on the day of admission before starting therapy, day 7 of treatment, the day of planned discharge (day 10-14), and 8 weeks after discharge.

RESULTS

We analyzed data from 135 patients; 78 (57.8%) were non-frequent exacerbators and 57 (42.2%) were frequent exacerbators. In both groups, the inflammatory and clinical indices at day 7, the day of planned discharge (day 10-14), and 8 weeks were significantly improved compared to those at admission. Frequent exacerbators had a smaller reduction in their inflammatory indices and CAT scores between exacerbation onset and all the other time points compared with infrequent exacerbators.

CONCLUSIONS

Frequent exacerbators have a reduced response to treatment of AECOPD in terms of inflammatory indices and quality of life.

Effect of levofloxacin on neutrophilic airway inflammation in stable COPD: a randomized, double-blind, placebo-controlled trial

Rationale

Airway inflammation persists after smoking cessation in established chronic obstructive pulmonary disease (COPD), suggesting that other factors drive the airway inflammatory response.

Objectives

We tested the hypothesis that high levels of bacterial colonization are associated with increased levels of neutrophilic airway inflammation in stable COPD by examining the cross-sectional relationship between these measurements and by conducting a randomized, double-blind, placebo-controlled study of the effect of levofloxacin in patients with stable COPD.

Methods

Patients were randomized to receive either levofloxacin 500 mg daily or placebo for 7 days and underwent sputum induction for a differential cell count and quantitative bacterial analysis at baseline and at days 7, 14, and 28.

Results

Sputum percentage neutrophil count correlated with airway bacterial load at baseline (r=0.56; P=0.003). Levofloxacin reduced bacterial load compared with placebo by 4.9-fold (95% confidence interval, 1.4–25.7; P=0.02) at day 7 but had no effect at any point on any marker of neutrophilic airway inflammation. In patients with a baseline bacterial load of more than 10⁶ cfu/mL, levofloxacin treatment was associated with a 26.5% (95% confidence interval, 1.8%–51.3%; P=0.04) greater reduction in the percentage neutrophil count compared with placebo at day 7. Change in percentage neutrophil count correlated significantly with baseline airway bacterial load and change in airway bacterial load.

Conclusion

In stable COPD, levofloxacin treatment causes a short-term reduction in bacterial load. This is associated with a reduction in neutrophilic airway inflammation in patients with high bacterial loads. Further studies are required to investigate whether this effect is clinically advantageous.

Sputum PGP is reduced by azithromycin treatment in patients with COPD and correlates with exacerbations

RATIONALE

Proline-glycine-proline (PGP), a neutrophil chemoattractant derived from the enzymatic breakdown of collagen, is elevated in sputum of patients with chronic obstructive pulmonary disease (COPD) and may contribute to disease progression. Whether sputum levels of PGP respond to therapy for COPD or predict outcomes is unknown.

OBJECTIVES

We conducted a study ancillary to a multicenter trial of the efficacy of azithromycin treatment for 1 year in preventing COPD exacerbations to test whether sputum levels of PGP were altered by treatment or associated with exacerbation frequency.

METHODS

We collected remnant sputa from trial participants and assayed them in a blinded fashion for PGP, myeloperoxidase and matrix metalloproteinase (MMP)-9 and for the ability to generate PGP from collagen ex vivo. Once the parent trial was unblinded, the results were correlated with use of azithromycin or placebo and exacerbations in participants.

RESULTS

Azithromycin treatment significantly reduced sputum levels of PGP and myeloperoxidase in patients with COPD, particularly with increased duration of therapy. We found no difference in sputum MMP-9 or PGP generation between participants taking azithromycin or placebo. Sputum PGP levels were highest around the time of an exacerbation and declined with successful treatment.

CONCLUSIONS

These data support a role for PGP in the airway and parenchymal neutrophilic inflammation that drives COPD progression and exacerbations, and provide new information on the anti-inflammatory properties of macrolides. PGP may have potential as a target for novel anti-inflammatory therapies in COPD and as a biomarker for clinical trials.

Cellular and molecular mechanisms of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease is associated with chronic inflammation affecting predominantly lung parenchyma and peripheral airways and results in largely irreversible and progressive airflow limitation. This inflammation is characterized by increased numbers of alveolar macrophages, neutrophils, and T lymphocytes, which are recruited from the circulation. Oxidative stress plays a key role in driving this inflammation. The pulmonary inflammation may enhance the development and growth of lung cancer. The peripheral inflammation extends into the circulation, resulting in systemic inflammation with the same inflammatory proteins. Systemic inflammation may worsen comorbidities. Treatment of pulmonary inflammation may therefore have beneficial effects.

Admission prevention in COPD: non-pharmacological management

Exacerbations of chronic obstructive pulmonary disease (COPD) are one of the commonest causes of hospital admission in Europe, Australasia, and North America. These adverse events have a large effect on the health status of the patients and impose a heavy burden on healthcare systems. While we acknowledge the contribution of pharmacotherapies to exacerbation prevention, our interpretation of the data is that exacerbations continue to be a major burden to individuals and healthcare systems, therefore, there remains great scope for other therapies to influence exacerbation frequency and preservation of quality of life. In this review, the benefits and limitations of pulmonary rehabilitation, non-invasive ventilation, smoking cessation, and long-term oxygen therapy are discussed. In addition, supported discharge, advanced care coordination, and telehealth programs to improve clinical outcome are reviewed as future directions for the management of COPD.

Pulmonary biomarkers in COPD exacerbations: a systematic review

Exacerbations of COPD (ECOPD) represent a major burden for patients and health care systems. Innovative sampling techniques have led to the identification of several pulmonary biomarkers. Although some molecules are promising, their usefulness in clinical practice is not yet established. Medline and Highwire databases were used to identify studies evaluating pulmonary sampled biomarkers in ECOPD. We combined 3 terms for ECOPD, 3 for biomarkers and 6 for the sampling method. Seventy-nine studies were considered eligible for inclusion in the review and were analyzed further. Pulmonary biomarkers sampled with non-invasive, semi-invasive and invasive methods were evaluated for their potential to illustrate the disease's clinical course, to correlate to clinical variables and to predict clinical outcomes, ECOPD etiology and response to treatment. According to published data several pulmonary biomarkers assessed in ECOPD have the potential to illustrate the natural history of disease through the modification of their levels. Among the clinically relevant molecules, those that have been studied the most and appear to be promising are spontaneous and induced sputum biomarkers for reflecting clinical severity and symptomatic recovery, as well as for directing towards an etiological diagnosis. Current evidence on the clinical usefulness of exhaled breath condensate and bronchoalveolar lavage biomarkers in ECOPD is limited. In conclusion, pulmonary biomarkers have the potential to provide information on the mechanisms underlying ECOPD, and several correlate with clinical variables and outcomes. However, on the basis of published evidence, no single molecule is adequately validated for wide clinical use. Clinical trials that incorporate biomarkers in decisional algorithms are required.

Serum biomarkers in elderly asthma

OBJECTIVE

Asthma is usually misdiagnosed and under-treated in the elderly population, resulting in complications and increased severity to the patient. In this review, we describe some of the most important serum markers of asthma studied so far, reporting their outcomes and possible prediction of asthma in the elderly population.

METHODS

The PubMed electronic database was used to search for promising serum biomarkers of asthma studied in original articles published in peer-reviewed journals from 2000 to January 2013.

RESULTS

A total of 13 relevant serum biomarkers were selected, including IgE, CRP, high sensitive CRP, IL-6, IL-8, IL-17, TNF-α, neopterin, serum amyloid A, eosinophil cationic protein, leukolysin, YKL-40 and soluble CD86.

CONCLUSIONS

Although the major focus of treatment and research has been on allergic asthma, several forms of the disease are recognized, such as neutrophilic asthma, which is characteristic of older patients. Different phenotypes imply different treatments and so it becomes important to correctly determine which type of asthma the patient is suffering from. Serum markers capable of supporting a diagnosis of asthma are needed in order to counter mistreatment and misdiagnosis with other obstructive airways disease (OAD) in elderly patients. As convenient as serum markers may seem to be, a marker capable of accurately identifying asthma with sufficient specificity is yet to be found.

The relationship between C-reactive protein and prognostic factors in chronic obstructive pulmonary disease

BACKGROUND

The purpose of the study was to determine the relationship between high sensitivity C-reactive protein (hs-CRP) levels and prognostic factors in chronic obstructive pulmonary disease.

METHODS

We studied 50 stable COPD patients with: spirometry, 6 minute walk distance, body mass index, GOLD stage (spirometric classification) and smoking status. In these patients hs-CRP values were measured and compared with those of 50 healthy controls. Then the serum hs-CRP was subjected to evaluation for any correlation with the predictors of outcomes in COPD subjects.

RESULTS

Hs-CRP levels were higher in COPD patients than in controls (4.82 vs. 0.88 mg/L p < 0.01). Correlation was found between hs-CRP and the following variables: FEV1 (r= -0.813; p < 0.01), 6MWD (r= -0.876; p < 0.01), body mass index (r= -0.710; p < 0.01), GOLD stage (r= 0.797, p < 0.01) and smoking status (r= 0.796; p < 0.01). Using multivariate analysis, FEV1 and 6MWD showed the strongest negative association with hs-CRP levels.

CONCLUSIONS

The circulating levels of the inflammatory marker hs-CRP are significantly elevated in patients with COPD, supporting the view that COPD is in part an inflammatory disorder. Hs-CRP levels in stable COPD patients are best correlated with FEV1 and 6-minute walk distance (6MWD). This information should be considered when hs-CRP levels are measured in stable COPD patients.

Critical assessment of the value of sputum neutrophils

Neutrophils are central to the pathogenesis of COPD, releasing a range of pro-inflammatory and tissue destructive mediators. Sputum neutrophil numbers are elevated in COPD patients compared to healthy controls. We critically appraise the potential of sputum neutrophils as a biomarker in COPD. We show that there is insufficient evidence to support the use of this biomarker to define a phenotype of patients with more severe disease characteristics or a different prognosis. However, sputum neutrophil measurements can be used to measure the effects of anti-inflammatory drugs for the treatment of COPD.

Interleukin-6 neutralization alleviates pulmonary inflammation in mice exposed to cigarette smoke and poly(I:C)

Increased systemic and pulmonary levels of IL-6 (interleukin-6) are associated with the severity of exacerbations and decline of lung function in patients with COPD (chronic obstructive pulmonary disease). Whether IL-6 is directly involved or plays a bystander role in the pathophysiology of COPD remains unclear. Here we hypothesized that neutralizing circulating levels of IL-6 would modulate episodes of acute pulmonary inflammation following CS (cigarette smoke) exposure and virus-like challenges. For this purpose, we used a model where C57BL/6 mice were exposed to CS twice daily via a nose-only system, and concomitant periodic intranasal challenge with poly(I:C), a synthetic ligand for TLR3 (Toll-like receptor 3) that mimics the encounter with double stranded RNA that is carried by influenza-like viruses. This protocol recapitulates several aspects of acute pulmonary inflammation associated with COPD, including prominent airway neutrophilia, insensitivity to steroid treatment and increased levels of several inflammatory cytokines in BAL (bronchoalveolar lavage) samples. Although IL-6-deficient mice exposed to CS/poly(I:C) developed pulmonary inflammation similar to WT (wild-type) controls, WT mice exposed to CS/poly(I:C) and treated intraperitoneally with IL-6-neutralizing antibodies showed significantly lower blood counts of lymphocytes and monocytes, lower BAL levels of IL-6 and CXCL1 (CXC chemokine ligand 1)/KC (keratinocyte chemoattractant), as well as reduced numbers of BAL neutrophils, lymphocytes and macrophages. Our results thus indicate that the systemic neutralization of IL-6 significantly reduces CS/poly(I:C)-induced pulmonary inflammation, which may be a relevant approach to the treatment of episodes of acute pulmonary inflammation associated with COPD.

Aberrant neutrophil functions in stable chronic obstructive pulmonary disease: the neutrophil as an immunotherapeutic target

Chronic obstructive pulmonary disease (COPD) is a common, progressive and debilitating chronic inflammatory condition affecting the lungs, with significant systemic manifestations and co-morbidities. Smoking cigarettes is the main risk factor, but only a fifth of smokers have clinically significant airflow obstruction and the inflammation persists after smoking cessation. This suggests that smoking (and exposure to other inhaled toxins) may be necessary but not sufficient to cause COPD. Neutrophils are believed central to COPD and their accumulation and degranulation are associated with tissue damage, increased inflammation and disordered tissue repair. It was assumed that neutrophil activity and function were appropriate in COPD, responding to the presence of high levels of inflammation in the lung. However more recent studies of neutrophil function (including migration, reactive oxygen species generation, degranulation, phagocytosis and extracellular trap (NET) production) suggest that there is a general impairment in COPD neutrophil responses that predispose towards increased inflammation and reduced bacterial clearance. This may be amenable to correction and manipulating neutrophil intracellular pathways (such as phosphoinositide-3-kinase signalling) appears to restore some key COPD neutrophil responses. Targeting neutrophil intra-cellular signalling may provide a means to normalise neutrophil behaviour in COPD. This could lead to improvements in disease outcomes by reducing extraneous inflammatory burden. However further studies are needed to determine if these findings are relevant in vivo and whether this would impact positively upon health and disease.

Mechanisms and impact of the frequent exacerbator phenotype in chronic obstructive pulmonary disease

Exacerbations of chronic obstructive pulmonary disease (COPD) are important events that carry significant consequences for patients. Some patients experience frequent exacerbations, and are now recognized as a distinct clinical subgroup, the 'frequent exacerbator' phenotype. This is relatively stable over time, occurs across disease severity, and is associated with poorer health outcomes. These patients are therefore a priority for research and treatment. The pathophysiology underlying the frequent exacerbator phenotype is complex, with increased airway and systemic inflammation, dynamic lung hyperinflation, changes in lower airway bacterial colonization and a possible increased susceptibility to viral infection. Frequent exacerbators are also at increased risk from comorbid extrapulmonary diseases including cardiovascular disease, gastroesophageal reflux, depression, osteoporosis and cognitive impairment. Overall these patients have poorer health status, accelerated forced expiratory volume over 1 s (FEV1) decline, worsened quality of life, and increased hospital admissions and mortality, contributing to increased exacerbation susceptibility and perpetuation of the frequent exacerbator phenotype. This review article sets out the definition and importance of the frequent exacerbator phenotype, with a detailed examination of its pathophysiology, impact and interaction with other comorbidities.

Association of biomarkers of inflammation and cell adhesion with lung function in the elderly: a population-based study

Background

Low lung function is associated with increased morbidity and mortality. It is therefore of interest to identify biomarkers that are associated with impaired lung function. The aim of the study was to analyse associations of biomarkers and combinations of biomarkers with lung function in an elderly general population.

Methods

Lung function (FEV₁ and FVC) and a panel of 15 inflammatory markers from blood samples were analysed in 888 subjects aged 70 years. Biomarkers included cytokines, chemokines, adhesion molecules, C-reactive protein (CRP) and leukocyte count.

Results

Leukocyte count and CRP were independently associated with FEV₁ after adjustments for other inflammatory markers, sex, BMI, current smoking and pack-years of smoking. In a similar model, leukocyte count and vascular cell adhesion protein 1 (VCAM-1) were the biomarkers that were significantly associated with FVC. Subjects that had both leukocyte count and CRP in the lowest tertile had a FEV₁ that was 9% of predicted higher than subjects with leukocyte count and CRP in the highest tertile (103±16 vs. 94±21% of predicted, p=0.0002) (mean±SD). A difference of 8% of predicted in FVC was found between subjects with leukocyte count and VCAM-1 in the lowest and highest tertiles, respectively (106±18 vs. 98±19% of predicted, p=0.002).

Conclusion

Leucocyte count, CRP and VCAM-1 were found to relate to poorer lung function. A dose related association was found for the combination leukocyte count and CRP towards FEV₁ and leukocyte and VCAM-1 towards FVC. This indicates that combination of two biomarkers yielded more information than assessing them one by one when analysing the association between systemic inflammation and lung function.

Comorbidity, systemic inflammation and outcomes in the ECLIPSE cohort

Comorbidities, are common in COPD, have been associated with poor outcomes and are thought to relate to systemic inflammation. To investigate comorbidities in relation to systemic inflammation and outcomes we recorded comorbidities in a well characterized cohort (ECLIPSE study) for 2164 clinically stable COPD subjects, 337 smokers and 245 non-smokers with normal lung function. COPD patients had a higher prevalence of osteoporosis, anxiety/panic attacks, heart trouble, heart attack, and heart failure, than smokers or nonsmokers. Heart failure (Hazard Ratio [HR] 1.9, 95% Confidence Interval [CI] 1.3-2.9), ischemic heart disease (HR 1.5, 95% CI 1.1-2.0), heart disease (HR 1.5, 95% CI 1.2-2.0), and diabetes (HR 1.7, 95% CI 1.2-2.4) had increased odds of mortality when coexistent with COPD. Multiple comorbidities had accumulative effect on mortality. COPD and cardiovascular disease was associated with poorer quality of life, higher MRC dyspnea scores, reduced 6MWD, higher BODE index scores. Osteoporosis, hypertension and diabetes were associated with higher MRC dyspnea scores and reduced 6MWD. Higher blood concentrations of fibrinogen, IL-6 and IL-8 levels occurred in those with heart disease. Comorbidity is associated with poor clinical outcomes in COPD. The comorbidities of heart disease, hypertension and diabetes are associated with increased systemic inflammation.

Blood specimen biomarkers of inflammation, matrix degradation, angiogenesis, and cardiac involvement: a future useful tool in assessing clinical outcomes of COPD patients in clinical practice?

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation that is not fully reversible; this airflow limitation is both progressive and associated with an abnormal inflammatory response of the lung to noxious particles or gasses. COPD is undoubtedly an umbrella term, and it seems unlikely that all patients with COPD have the same underlying disease processes; thus, there is a need for differential treatment of different subgroups. A potential solution is to find modifiable biomarkers that can assist in drug development and distinguish subgroups of COPD. With the exception of lung function tests, there are currently no well-validated biomarkers or surrogate endpoints that can be used to establish the efficacy of a drug for COPD. This article discusses biomarkers of inflammation (fibrinogen, C-reactive protein, pulmonary and activation-regulated chemokine/CC-chemokine ligand-18, serum surfactant protein D, interleukin (IL)-6, IL-8 and tumor necrosis factor α, complement factor C5a), angiogenesis factors as a part of the pathogenetic aspect in this disease (vascular endothelial growth factor, angiogenin, and IL-8), and matrix degradation biomarkers. Troponin and natriuretic peptides are presented as biomarkers of cardiac involvement in the light of COPD comorbidities. Trials based on research on known clinical variables such as FEV1, BODE, and 6MWT in combination with biomarkers from lung and blood specimens will probably clarify part of the prognosis and natural history of the disease. This will also represent an additional step in COPD phenotyping and new treatment possibilities.

Systemic inflammatory biomarkers and co-morbidities of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) can no longer be considered as a disease affecting only the lungs. Increasing evidence supports the presence of a systemic inflammatory component which is thought to provide the link between COPD and the co-morbidities commonly associated with this disease. These include cardiovascular disorders, skeletal muscle dysfunction, diabetes, and osteoporosis. The majority of current therapies for COPD have been developed to improve airway obstruction or to target airway inflammation, leaving an unmet medical need with respect to the systemic inflammatory component of COPD and its extra-pulmonary manifestations. This review describes systemic biomarkers in COPD and their relationship with both the local lung and systemic manifestations of the disease. A summary is provided of the most promising biomarkers that have been investigated in COPD and its co-morbidities. Such biomarkers may be used to assess and manage the systemic effects of COPD, and may guide future development of novel therapeutic interventions to provide a more holistic approach to treating this multi-faceted disease.

Adhesion molecules in subjects with COPD and healthy non-smokers: a cross sectional parallel group study

Background

The aim of the study was to investigate how the expression of adhesion molecules changes as neutrophils migrate from the circulation to the lung and if these changes differ between non-smoking subjects and smokers with and without COPD.

Methods

Non-smoking healthy subjects (n=22), smokers without (n=21) and with COPD (n=18) were included. Neutrophils from peripheral blood, sputum and bronchial biopsies were analysed for cell surface expression of adhesion molecules (CD11b, CD62L, CD162). Serum, sputum supernatant and BAL-fluid were analysed for soluble adhesion molecules (ICAM-1, -3, E-selectin, P-selectin, VCAM-1, PECAM-1).

Results

Expression of CD11b was increased on circulating neutrophils from smokers with COPD. It was also increased on sputum neutrophils in both smokers groups, but not in non-smokers, as compared to circulating neutrophils.

Serum ICAM-1 was higher in the COPD group compared to the other two groups (p<0.05) and PECAM-1 was lower in smokers without COPD than in non-smoking controls and the COPD group (p<0.05). In BAL-fluid ICAM-1 was lower in the COPD group than in the other groups (p<0.05).

Conclusions

Thus, our data strongly support the involvement of a systemic component in COPD and demonstrate that in smokers neutrophils are activated to a greater extent at the point of transition from the circulation into the lungs than in non-smokers.

Increased cytokines response in patients with tuberculosis complicated with chronic obstructive pulmonary disease

Objectives

To explore the change and its significance of cytokines in patients with pulmonary tuberculosis complicated with COPD.

Methods

The immune function of 152 cases of pulmonary tuberculosis with COPD was detected to compare with 150 cases of patients with pulmonary tuberculosis, 157 cases of patients with COPD and 50 cases of healthy volunteers who were in the hospital during the same period. T lymphocyte cell population in peripheral blood was detected by flow cytometry. The serum levels of sIL-2R, IL-6, IFN-γ, TNF-α were measured using ELISA.

Results

The percentage of CD4+ T cells in TB patients with or without COPD and COPD patients without TB was significantly lower than that in control group. The percentage of CD4+ T cells in patients with TB and COPD was significantly lower than that in the non-COPD TB patients. The percentage of CD8+ T cells was higher in the TB patients group than that in control group. The CD4+/CD8+ ratio in the TB patients group was significantly lower than that in control group. The concentrations of sIL-2R, IL-6, TNF-α, IFN-γ in TB patients with or without COPD and COPD patients without TB were significantly higher than those in control group. In addition, sIL-2R, IL-6, TNF-α concentrations in the patients with TB and COPD were higher than those in the non-COPD TB patients. The concentrations of sIL-2R, IL-6, TNF-α, IFN-γ in COPD patients with TB were significantly higher than those in COPD patients without TB. There was a significant negative correlation between serum levels of TNF-α, IL-6 and FEV1 (%, predicted) in COPD without TB group.

Conclusions

The patients with pulmonary tuberculosis complicated with COPD were impaired in cellular immunity, and its extent of immune impairment is more serious than those of the patients with pulmonary tuberculosis and the patients with COPD.

Lung function decline in male heavy smokers relates to baseline airflow obstruction severity

BACKGROUND

Recent evidence indicates that the rate of lung function decline is steepest in mild COPD and slower in moderate to severe COPD. The current study assessed whether lung function decline relates to baseline airflow obstruction severity in male heavy smokers.

METHODS

In total, 2,003 male smokers with a mean (SD) age of 59.8 (5.3) years underwent pulmonary function testing at baseline and after 3-year follow-up. Participants were classified by entry FEV1/FVC as follows: group 1, >70%; group 2, <70%, but greater than lower limit of normal (LLN); and group 3, less than LLN. Differences in lung function decline among the groups were assessed using multiple regression after adjustment for pack-years, smoking status (current or former smoker), presence or absence of mucus production, medical center, height, age, CT scan-derived emphysema severity (15th percentile), observation time (years in study), and the baseline values.

RESULTS

Over 3 years, the mean (SD) FEV₁/FVC, FEV₁, and maximum expiratory flow at 50% of FVC decreases in group 1 were 3.1% (1), 0.21 L (0.07), and 0.40 L/s (0.26), respectively. In group 3, these decreases were 2.4% (1.1), 0.15 L (0.08), and 0.06 L/s (0.19), respectively. All lung function parameters showed the greatest decline in group 1 (P < .001).

CONCLUSIONS

Diagnosing COPD based on the presence of more severe airflow obstruction (as defined by FEV₁/FVC less than LLN) means that, at the time of such a diagnosis, subjects had passed the phase of strong lung-function decline.

TRIAL REGISTRY

ISRCTN Register; No.: ISRCTN63545820; URL: www.trialregister.nl

Physico-chemical characterization of African urban aerosols (Bamako in Mali and Dakar in Senegal) and their toxic effects in human bronchial epithelial cells: description of a worrying situation

Background

The involvement of particulate matter (PM) in cardiorespiratory diseases is now established in developed countries whereas in developing areas such as Africa with a high level of specific pollution, PM pollution and its effects are poorly studied. Our objective was to characterize the biological reactivity of urban African aerosols on human bronchial epithelial cells in relation to PM physico-chemical properties to identify toxic sources.

Methods

Size-speciated aerosol chemical composition was analyzed in Bamako (BK, Mali, 2 samples with one having desert dust event BK1) and Dakar (DK; Senegal) for Ultrafine UF, Fine F and Coarse C PM. PM reactivity was studied in human bronchial epithelial cells investigating six biomarkers (oxidative stress responsive genes and pro-inflammatory cytokines).

Results

PM mass concentrations were mainly distributed in coarse mode (60%) and were impressive in BK1 due to the desert dust event. BK2 and DK samples showed a high content of total carbon characteristic of urban areas. The DK sample had huge PAH quantities in bulk aerosol compared with BK that had more water soluble organic carbon and metals. Whatever the site, UF and F PM triggered the mRNA expression of the different biomarkers whereas coarse PM had little or no effect. The GM-CSF biomarker was the most discriminating and showed the strongest pro-inflammatory effect of BK2 PM. The analysis of gene expression signature and of their correlation with main PM compounds revealed that PM-induced responses are mainly related to organic compounds. The toxicity of African aerosols is carried by the finest PM as with Parisian aerosols, but when considering PM mass concentrations, the African population is more highly exposed to toxic particulate pollution than French population. Regarding the prevailing sources in each site, aerosol biological impacts are higher for incomplete combustion sources resulting from two-wheel vehicles and domestic fires than from diesel vehicles (Dakar). Desert dust events seem to produce fewer biological impacts than anthropogenic sources.

Discussion

Our study shows that combustion sources contribute to the high toxicity of F and UF PM of African urban aerosols, and underlines the importance of emission mitigation and the imperative need to evaluate and to regulate particulate pollution in Africa.

Pulmonary function predicting confirmed recovery from lower-respiratory symptoms in World Trade Center-exposed firefighters, 2001 to 2010

BACKGROUND

We examined the relationship between pulmonary function (FEV 1 ) and confirmed recovery from three lower-respiratory symptoms (LRSs) (cough, dyspnea, and wheeze) up to 9 years after symptom onset.

METHODS

The study included white and black male World Trade Center (WTC)-exposed firefighters who reported at least one LRS on a medical monitoring examination during the fi rst year after September 11, 2001. Confirmed recovery was defined as reporting no LRSs on two consecutive and all subsequent examinations. FEV 1 was assessed at the fi rst post-September 11, 2001, examination and at each examination where symptom information was ascertained. We used stratified Cox regression models to analyze FEV 1 , WTC exposure, and other variables in relation to confirmed symptom recovery.

RESULTS

A total of 4,368 fi refighters met inclusion criteria and were symptomatic at year 1, of whom1,592 (36.4%) experienced confirmed recovery. In univariable models, fi rst post-September 11,2001, concurrent, and difference between fi rst post-September 11, 2001, and concurrent FEV 1 values were all significantly associated with confirmed recovery. In adjusted analyses, both fi rst post-September 11, 2001, FEV 1 (hazard ratio [HR], 1.07 per 355-mL difference; 95% CI, 1.04-1.10) and FEV 1 % predicted (HR, 1.08 per 10% predicted difference; 95% CI, 1.04-1.12) predicted confirmed recovery. WTC exposure had an inverse association with confirmed recovery in the model with FEV 1 , with the earliest arrival group less likely to recover than the latest arrival group (HR, 0.73;95% CI, 0.58-0.92).

CONCLUSIONS

Higher FEV 1 and improvement in FEV 1 after September 11, 2001, predicted confirmed LRS recovery, supporting a physiologic basis for recovery and highlighting consideration of spirometry as part of any postexposure respiratory health assessment.