Global burden of COPD: risk factors, prevalence, and future trends

Association of MMP-2 polymorphisms with severe and very severe COPD: a case control study of MMPs-1, 9 and 12 in a European population

BACKGROUND

Genetic factors play a role in chronic obstructive pulmonary disease (COPD) but are poorly understood. A number of candidate genes have been proposed on the basis of the pathogenesis of COPD. These include the matrix metalloproteinase (MMP) genes which play a role in tissue remodelling and fit in with the protease--antiprotease imbalance theory for the cause of COPD. Previous genetic studies of MMPs in COPD have had inadequate coverage of the genes, and have reported conflicting associations of both single nucleotide polymorphisms (SNPs) and SNP haplotypes, plausibly due to under-powered studies.

METHODS

To address these issues we genotyped 26 SNPs, providing comprehensive coverage of reported SNP variation, in MMPs- 1, 9 and 12 from 977 COPD patients and 876 non-diseased smokers of European descent and evaluated their association with disease singly and in haplotype combinations. We used logistic regression to adjust for age, gender, centre and smoking history.

RESULTS

Haplotypes of two SNPs in MMP-12 (rs652438 and rs2276109), showed an association with severe/very severe disease, corresponding to GOLD Stages III and IV.

CONCLUSIONS

Those with the common A-A haplotype for these two SNPs were at greater risk of developing severe/very severe disease (p = 0.0039) while possession of the minor G variants at either SNP locus had a protective effect (adjusted odds ratio of 0.76; 95% CI 0.61 - 0.94). The A-A haplotype was also associated with significantly lower predicted FEV1 (42.62% versus 44.79%; p = 0.0129). This implicates haplotypes of MMP-12 as modifiers of disease severity.

R, Ost D, Truwit J, Diaz P, Wahidi M, Cerfolio R, Maxfield R, Musani A, Gildea T, Sheski F, Machuzak M, Haas A, Gonzalez H, Springmeyer S. A multicenter pilot study of a bronchial valve for the treatment of severe emphysema

BACKGROUND

Chronic obstructive pulmonary disease (COPD) affects millions of people and has limited treatment options. Surgical treatments for severe COPD with emphysema are effective for highly selected patients. A minimally invasive method for treating emphysema could decrease morbidity and increase acceptance by patients.

OBJECTIVE

To study the safety and effectiveness of the IBV(R) Valve for the treatment of severe emphysema.

METHODS

A multicenter study treated 91 patients with severe obstruction, hyperinflation and upper lobe (UL)-predominant emphysema with 609 bronchial valves placed bilaterally into ULs.

RESULTS

Valves were placed in desired airways with 99.7% technical success and no migration or erosion. There were no procedure-related deaths and 30-day morbidity and mortality were 5.5 and 1.1%, respectively. Pneumothorax was the most frequent serious device-related complication and primarily occurred when all segments of a lobe, especially the left UL, were occluded. Highly significant health-related quality of life (HRQL) improvement (-8.2 +/- 16.2, mean +/- SD change at 6 months) was observed. HRQL improvement was associated with a decreased volume (mean -294 +/- 427 ml, p = 0.007) in the treated lobes without visible atelectasis. FEV(1), exercise tests, and total lung volume were not changed but there was a proportional shift, a redirection of inspired volume to the untreated lobes. Combined with perfusion scan changes, this suggests that there is improved ventilation and perfusion matching in non-UL lung parenchyma.

CONCLUSION

Bronchial valve treatment of emphysema has multiple mechanisms of action and acceptable safety, and significantly improves quality of life for the majority of patients.

A profile of volatile organic compounds in breath discriminates COPD patients from controls

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is an inflammatory condition characterized by oxidative stress and the formation of volatile organic compounds (VOCs) secreted via the lungs. We recently developed a methodological approach able to identify profiles of VOCs in breath unique for patient groups. Here we applied this recently developed methodology regarding diagnosis of COPD patients.

METHODS

Fifty COPD patients and 29 controls provided their breath and VOCs were analyzed by gas chromatography-mass spectrometry to identify relevant VOCs. An additional 16 COPD patients and 16 controls were sampled in order to validate the model, and 15 steroid naïve COPD patients were sampled to determine whether steroid use affects performance.

FINDINGS

1179 different VOCs were detected, of which 13 were sufficient to correctly classify all 79 subjects. Six of these 13 VOCs classified 92% of the subjects correctly (sensitivity: 98%, specificity: 88%) and correctly classified 29 of 32 subjects (sensitivity: 100%, specificity: 81%) from the independent validation population. Fourteen out of 15 steroid naïve COPD patients were correctly classified thus excluding treatment influences.

INTERPRETATION

This is the first study distinguishing COPD subjects from controls solely based on the presence of VOCs in breath. Analysis of VOCs might be highly relevant for diagnosis of COPD.

C-reactive protein as a predictor of disease in smokers and former smokers: a review

BACKGROUND

Cigarette smoking is a classical and a major risk factor in the development of several diseases with an inflammatory component, including cardiovascular disease and chronic obstructive pulmonary disease. Improvements in assays for protein markers of inflammation have led to many studies on these factors and their roles in disease.

AIMS

C-reactive protein (CRP) is one such marker and this review focuses on the evidence for using CRP as a diagnostic marker and how levels of this protein are modified according to the smoking status of the patient, both in terms of the current amount of cigarettes smoked and how CRP levels change following smoking cessation.

CONCLUSIONS

Assay of CRP levels may be useful in monitoring disease progression and determining risk of future cardiovascular complications. However, as this marker is also an indicator of acute inflammation and challenges to the immune system, some caution must be exercised in interpreting the available data on CRP levels in patients with different chronic comorbidities.

Effect of airway clearance techniques in patients experiencing an acute exacerbation of chronic obstructive pulmonary disease: A systematic review

Answers were sought to the following question: Are techniques, applied predominantly with the aim of clearing secretions from the airways, to patients during an acute exacerbation of chronic obstructive pulmonary disease (AECOPD), safe and effective? A systematic review was undertaken of studies that (i) were either randomized controlled or randomized cross-over trials, (ii) recruited patients during an AECOPD, (iii) reported the results of between-group analyses and (iv) investigated the effect of techniques applied primarily with the aim of clearing secretions from the airways. Studies that examined non-invasive positive pressure ventilation (NIPPV) and early rehabilitation were excluded. Data were extracted pertaining to resting lung function, gas exchange, sputum expectoration, symptoms, NIPPV use and hospital stay. Five studies were included with a mean Physiotherapy Evidence Database (PEDro) score of 4.4 ± 1.1 (range: 3—6). The main findings were that (i) airway clearance techniques did not improve measures of resting lung function or produce any consistent change in measures of gas exchange, (ii) the application of 5 min of continuous chest wall percussion reduced forced expiratory volume in 1 second (FEV 1), (iii) in people with copious secretions, mechanical vibration, and non-oscillating positive expiratory pressure (PEP) mask therapy increased sputum expectoration and (iv) in patients with hypercapnic respiratory failure, intrapulmonary percussive ventilation (IPV) and PEP mask therapy reduced the need for, and duration of, NIPPV, respectively. With the exception of continuous chest wall percussion, airway clearance techniques were safe in patients during an AECOPD. Vibration and non-oscillating PEP facilitated sputum expectoration in patients characterized by copious airway secretions. In patients with respiratory failure, techniques that apply a positive pressure to the airways may reduce either the need for, or duration of, NIPPV and hospital length of stay.

COPD and the risk of depression

BACKGROUND

Chronic comorbidities are often associated with depression. Most previous studies exploring the association between COPD and depression were rather small and based on a cross-sectional study design. We conducted a large population-based study on the risk of developing an incident depression diagnosis in association with a previous COPD diagnosis.

METHODS

We used the UK-based General Practice Research Database to assess and compare the prevalence of a history of depression and to quantify the risk of developing incident depression in patients with COPD and patients without COPD between 1995 and 2005. We conducted a nested case-control analysis, matching up to four patients who did not develop depression for each case patient with depression, to further analyze the impact of COPD severity.

RESULTS

In a study population of 35,722 patients with COPD and 35,722 patients without COPD, the prevalence of diagnosed depression prior to the first COPD diagnosis was higher in the population with COPD (23.1%) than among patients without COPD (16.8%). The incidence rate of a new-onset diagnosis of depression after the first COPD diagnosis was 16.2/1,000 person-years (py) in the COPD group, whereas it was only 9.4/1,000 py in the COPD-free comparison group. In the nested case-control analysis, patients with severe COPD had the highest risk of developing depression (odds ratio, 2.01; 95% CI, 1.45-2.78).

CONCLUSION

This large observational study provides further evidence that patients with COPD are at an increased risk of developing depression.

The burden of COPD in Africa: a literature review and prospective survey of the availability of spirometry for COPD diagnosis in Africa

OBJECTIVES

To ascertain the known burden of chronic obstructive pulmonary disease (COPD) in Africa and of spirometry use to indicate the possibility of further unpublished data becoming shortly available.

METHOD

Literature review.

RESULTS

Screening of 132 articles yielded 22 relevant articles, of which only six used spirometry based data. A total of 106 physicians in 34 countries were contacted and only 23 reported satisfactory use and availability of spirometry.

CONCLUSIONS

Current estimates of COPD burden in Africa are based on an unreliably small dataset. Acquisition of further data will require substantial investment in lung function equipment and training.

Characterization of proteins Msp22 and Msp75 as vaccine antigens of Moraxella catarrhalis

Moraxella catarrhalis is a respiratory tract pathogen causing otitis media in children and respiratory tract infections in adults with chronic obstructive pulmonary disease. This study examined two newly identified proteins as potential vaccine antigens. Antisera raised to recombinant purified proteins Msp22 and Msp75 recognized corresponding native proteins in multiple strains of M. catarrhalis. Vaccine formulations individually administered subcutaneously and intranasally showed enhanced clearance of M. catarrhalis in a mouse pulmonary clearance model by both routes of administration. Msp22 and Msp75 are antigenically conserved proteins that induce potentially protective immune responses and should be examined further as vaccine antigens for M. catarrhalis.

Accelerated lung aging: a novel pathogenic mechanism of chronic obstructive pulmonary disease (COPD)

An enhanced or abnormal inflammatory response to the lungs to inhaled particles and gases, usually from cigarette smoke, is considered to be a general pathogenic mechanism in COPD (chronic obstructive pulmonary disease). Activation of leucocytes and the development of oxidant-antioxidant and protease-anti-protease imbalances are thought to be important aspects of this enhanced inflammatory response to cigarette smoke. The mechanisms involved in the perpetuation of the inflammatory response in the lungs in patients who develop COPD, even after smoking cessation, are not fully established and are key to our understanding of the pathogenic mechanisms in COPD and may be important for the development of new therapies. There is a relationship between chronic inflammatory diseases and aging, and the processes involved in aging may provide a novel mechanism in the pathogenesis of COPD. There is good evidence linking aging and COPD. During normal aging, pulmonary function deteriorates progressively and pulmonary inflammation increases, accompanied in the lungs by the features of emphysema. These features are accelerated in COPD. Emphysema is associated with markers of accelerated aging in the lungs, and COPD is also associated with features of accelerated aging in other organs, such as the cardiovascular and musculoskeletal systems. Cigarette smoke and other oxidative stresses result in cellular senescence and accelerate lung aging. There is also evidence that anti-aging molecules such as histone deacetylases and sirtuins are decreased in the lungs of COPD patients, compared with smokers without COPD, resulting in enhanced inflammation and further progression of COPD. The processes involved in accelerated aging may provide novel targets for therapy in COPD. The present article reviews the evidence for accelerated aging as a mechanism in the pathogenesis of COPD.

[The gap between the high impact and low awareness of COPD in the population]

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is markedly under-diagnosed, which may relate to under-reporting of symptoms and poor awareness of the disease.

METHODS

A survey was conducted in a sample of the French general population aged 40-75 years (n=2758) to assess respiratory symptoms and level of knowledge of the disease in subjects with or at-risk of COPD (n=860, 31%).

RESULTS

The high frequency of dyspnoea (MRC dyspnoea grade > or =1: 40%) contrasted with that of subjects spontaneously reporting respiratory problems (9%). Among these, 72% reported limitations in daily-life activities but only 14% considered that they were severely affected by their respiratory status. A very low proportion of subjects knew the term COPD (8%) and only 66% of these associated COPD with a respiratory disease.

CONCLUSIONS

There is a wide gap between the high number of subjects at risk of COPD in the general population and the frequency of breathlessness in these subjects on one hand, and the poor knowledge of the disease, poor perception of symptoms, and under-diagnosis and under-use of spirometry on the other. Increasing awareness of COPD in the population is needed.

Expansion of the prognostic assessment of patients with chronic obstructive pulmonary disease: the updated BODE index and the ADO index

BACKGROUND

The BODE index (including body-mass index, airflow obstruction, dyspnoea, and exercise capacity) was an important contribution to the prognostic assessment of patients with chronic obstructive pulmonary disease (COPD). However, no study has assessed whether the risk of mortality predicted by the BODE index matches the observed mortality in different populations. We assessed the calibration of the BODE index, updated it to improve its calibration, and developed and validated a simplified index for use in primary-care settings.

METHODS

We included 232 patients from the Swiss Barmelweid cohort with longstanding and severe COPD and 342 patients from the Spanish Phenotype and Course of COPD cohort study who had had their first hospital admission due to moderate-to-severe COPD. In both cohorts we compared the observed 3-year risk of all-cause mortality with the risk predicted by the BODE index. We then updated the BODE index and developed a simplified ADO index (including age, dyspnoea, and airflow obstruction) from the Swiss cohort, and validated both in the Spanish cohort.

FINDINGS

Calibration of the BODE index was poor, with relative underprediction of 3-year risk of mortality by 36% in the Swiss cohort (median predicted risk 21.7% [IQR 12.7-31.7] vs 34.1% observed risk; p=0.013) and relative overprediction by 39% in the Spanish cohort (16.7% [12.7-31.7] vs 12.0%; p=0.035). The 3-year risk of mortality predicted by both the updated BODE (median 10.7% [8.1-13.8]) and ADO indices (11.8% [9.1-14.3]) matched the observed mortality in the Spanish cohort well (p=0.99 and p=0.98, respectively).

INTERPRETATION

Both the updated BODE and ADO indices could lend support to the prognostic assessment of patients with COPD in specialised and primary-care settings. Such assessment enhances the targeting of treatments to individual patients.

FUNDING

Swiss National Science Foundation; Klinik Barmelweid; Fondo de Investigación Sanitaria Ministry of Health, Spain; Agència d'Avaluació de Tecnologia i Recerca Mèdiques, Catalonia Government; Spanish Society of Pneumology and Thoracic Surgery; Catalan Foundation of Pneumology; Red RESPIRA; Red RCESP; Fondo de Investigación Sanitaria; Fondo de Investigación Sanitaria; Fundació La Marató de TV3; Novartis Farmacèutica, Spain.

Evolution of emphysema in relation to smoking

PURPOSE

We have little knowledge about the evolution of emphysema, and relatively little is understood about its evolution in relation to smoking habits. This study aims to assess the evolution of emphysema in asymptomatic current and former smokers over 2 years and to investigate the association with subjects' characteristics. The study was approved by our Ethics Committee and all participants provided written informed consent.

MATERIALS AND METHODS

We measured emphysema by automatic low-dose computed tomography densitometry in 254 current and 282 former smokers enrolled in a lung-cancer screening. The measures were repeated after 2 years. The association between subjects' characteristics, smoking habits and emphysema were assessed by chi-squared and Wilcoxon tests. Univariate and multivariate odds ratios (OR) with 95% confidence intervals (CI) were calculated for the risk of emphysema worsening according to subjects' characteristics. We assessed the trend of increasing risk of emphysema progression by smoking habits using the Mantel-Haenszel chi-squared test.

RESULTS

The median percentage increase in emphysema over a 2-year period was significantly higher in current than in former smokers (OR 1.8; 95% CI 1.3-2.6; p < 0.0001). The risk of worsening emphysema (by 30% in 2 years) in current smokers increased with smoking duration (p for trend <0.02).

CONCLUSION

As emphysema is a known risk factor for lung cancer, its evaluation could be used as a potential factor for identification of a high-risk population. The evaluation of emphysema progression can be added to low-dose CT screening programmes to inform and incite participants to stop smoking.

Long-term outcomes in mild/moderate chronic obstructive pulmonary disease in the European community respiratory health survey

RATIONALE

Little is known about the long-term outcomes of individuals with mild/moderate chronic obstructive pulmonary disease (COPD) according to spirometric criteria.

OBJECTIVES

To test whether nonsmokers and asymptomatic subjects with a spirometric diagnosis of COPD have a steeper decrease in lung function and higher hospitalization rates than subjects without airway obstruction.

METHODS

A total of 5,205 subjects without asthma (20-44 years of age) from the general population, with FEV(1) >or= 50% predicted at baseline, were followed for 9 years in the frame of an international cohort study. Percent decrease in FEV(1) (DeltaFEV(1)%) and the annual hospitalization rate for respiratory causes during the follow-up were assessed for each subject.

MEASUREMENTS AND MAIN RESULTS

At baseline, 324 (6.2%) subjects had the prebronchodilator FEV(1)/FVC ratio less than the lower limit of normal (LLN-COPD), and 105 (2.0%) subjects had the same ratio less than 0.70 (modified GOLD-COPD). At follow-up, smokers with LLN-COPD (n = 205) had a greater mean DeltaFEV(1)% (1.7%; 95% confidence interval [CI], 0.8-2.7) and a higher hospitalization rate (rate ratio [RR], 2.52; 95% CI, 1.65-3.86) than normal subjects. Similarly, symptomatic subjects with LLN-COPD (n = 104) had DeltaFEV(1)% (2.0%; 95% CI, 0.8-3.3) and the hospitalization rate (RR, 4.18; 95% CI, 2.43-7.21) higher than the reference group. By contrast, nonsmokers and asymptomatic subjects with LLN-COPD had outcomes that were similar or even better than normal subjects. Among subjects with LLN-COPD, the association of symptoms with DeltaFEV(1)% varied according to smoking habits (P = 0.007); it was particularly strong in symptomatic smokers and disappeared in symptomatic nonsmokers. Similar results were found with the modified GOLD classification.

CONCLUSIONS

In relatively young populations, COPD is associated with poor long-term outcomes in smokers and in symptomatic subjects only.

Smoking, nicotine and neuropsychiatric disorders

Tobacco smoking is an extremely addictive and harmful form of nicotine (NIC) consumption, but unfortunately also the most prevalent. Although disproportionately high frequencies of smoking and its health consequences among psychiatric patients are widely known, the neurobiological background of this epidemiological association is still obscure. The diverse neuroactive effects of NIC and some other major tobacco smoke constituents in the central nervous system may underlie this association. This present paper summarizes the pharmacology of NIC and its receptors (nAChR) based on a systematic review of the literature. The role of the brain's reward system(s) in NIC addiction and the results of functional and structural neuroimaging studies on smoking-related states and behaviors (i.e. dependence, craving, withdrawal) are also discussed. In addition, the epidemiological, neurobiological, and genetic aspects of smoking in several specific neuropsychiatric disorders are reviewed and the clinical relevance of smoking in these disease states addressed.

Management and prevention of chronic obstructive pulmonary disease exacerbations: a state of the art review

Exacerbations of chronic obstructive pulmonary disease (COPD) are important events in the natural history of this prevalent and devastating condition. This review provides a concise, state of the art summary on prevention and management of exacerbations. Considerable new data underpins evidence in support of many preventative interventions, pharmacological and non-pharmacological, that are now available. Challenges remain in developing new approaches, and delivering those that already exist to the right patient at the right time. Management of an exacerbation remains stepwise according to clinical severity, but there is now additional focus on addressing comorbidities and taking the opportunity at acute events to optimise preventative strategies for the future. Ultimately, exacerbations are heterogeneous events in a heterogeneous disease, and an individualised approach is paramount.

Chronic obstructive pulmonary disease and obstructive sleep apnea: overlaps in pathophysiology, systemic inflammation, and cardiovascular disease

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea syndrome represent two of the most prevalent chronic respiratory disorders in clinical practice, and cardiovascular diseases represent a major comorbidity in each disorder. The two disorders coexist (overlap syndrome) in approximately 1% of adults but asymptomatic lower airway obstruction together with sleep-disordered breathing is more prevalent. Although obstructive sleep apnea syndrome has similar prevalence in COPD as the general population, and vice versa, factors such as body mass index and smoking influence relationships. Nocturnal oxygen desaturation develops in COPD, independent of apnea/hypopnea, and is more severe in the overlap syndrome, thus predisposing to pulmonary hypertension. Furthermore, upper airway flow limitation contributes to nocturnal desaturation in COPD without apnea/hypopnea. Evidence of systemic inflammation in COPD and sleep apnea, involving C-reactive protein and IL-6, in addition to nuclear factor-kappaB-dependent pathways involving tumor necrosis factor-alpha and IL-8, provides insight into potential basic interactions between both disorders. Furthermore, oxidative stress develops in each disorder, in addition to activation and/or dysfunction of circulating leukocytes. These findings are clinically relevant because systemic inflammation may contribute to the pathogenesis of cardiovascular diseases and the cell/molecular pathways involved are similar to those identified in COPD and sleep apnea. However, the pathophysiological and clinical significance of systemic inflammation in COPD and sleep apnea is not proven, and thus, studies of patients with the overlap syndrome should provide insight into the mechanisms of systemic inflammation in COPD and sleep apnea, in addition to potential relationships with cardiovascular disease.

Effect of reducing indoor air pollution on women's respiratory symptoms and lung function: the RESPIRE Randomized Trial, Guatemala

Exposure to household wood smoke from cooking is a risk factor for chronic obstructive lung disease among women in developing countries. The Randomized Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) is a randomized intervention trial evaluating the respiratory health effects of reducing indoor air pollution from open cooking fires. A total of 504 rural Mayan women in highland Guatemala aged 15-50 years, all using traditional indoor open fires, were randomized to either receive a chimney woodstove (plancha) or continue using the open fire. Assessments of chronic respiratory symptoms and lung function and individual measurements of carbon monoxide exposure were performed at baseline and every 6 months up to 18 months. Use of a plancha significantly reduced carbon monoxide exposure by 61.6%. For all respiratory symptoms, reductions in risk were observed in the plancha group during follow-up; the reduction was statistically significant for wheeze (relative risk = 0.42, 95% confidence interval: 0.25, 0.70). The number of respiratory symptoms reported by the women at each follow-up point was also significantly reduced by the plancha (odds ratio = 0.7, 95% confidence interval: 0.50, 0.97). However, no significant effects on lung function were found after 12-18 months. Reducing indoor air pollution from household biomass burning may relieve symptoms consistent with chronic respiratory tract irritation.

Innate immune receptors on neutrophils and their role in chronic lung disease

Neutrophils, the prototypic cells of the innate immune system, are recruited to infected sites to protect the human body from invading pathogens. To accomplish this function, neutrophils sense pathogens and endogenous damage-associated molecules via innate immune receptors, such as Toll-like receptors (TLRs) and other pattern recognition receptors. This defence function is essential for the pulmonary microenvironment where the host is faced with millions of particles and pathogens inhaled daily. Chronic lung diseases, such as cystic fibrosis or chronic obstructive pulmonary disease are characterized by a neutrophil accumulation and chronic bacterial colonization of the airways. Consequently, insights into the role of TLRs on neutrophils in chronic lung diseases are of high relevance for further diagnostic and therapeutic approaches. Here we summarize and discuss recent advances in the expression, regulation and functional role of TLRs on neutrophils in chronic lung diseases.

Leptin receptor polymorphisms and lung function decline in COPD

Only a fraction of all smokers develop chronic obstructive pulmonary disease (COPD), suggesting a large role for genetic susceptibility. The leptin receptor (LEPR) is present in human lung tissue and may play a role in COPD pathogenesis. The present study examined the association between genetic variants in the LEPR gene and lung function decline in COPD. In total, 429 European Americans were randomly selected from the National Heart Lung and Blood Institute Lung Health Study. 36 single nucleotide polymorphisms (SNPs) in LEPR were genotyped using the Illumina GoldenGate platform (Broad Institute, Cambridge, MA, USA). Mean annual decline in forced expiratory volume in 1 s % predicted over the 5-yr period was calculated using linear regression. Linear regression models were also used to adjust for potential confounders. In addition, in vivo expression of the receptor gene was assessed with immunohistochemistry on lungs from smoke-exposed inbred mice. We identified significant associations (p<0.05) between lung function decline and 21 SNPs. Haplotype analyses confirmed several of these associations seen with individual markers. Immunohistochemistry results in inbred mice strains support a potential role of LEPR in COPD pathogenesis. We identified genetic variants in the LEPR gene significantly associated with lung function decline in a population of smokers with COPD. Our results support a role for LEPR as a novel candidate gene for COPD.

Exacerbation rate, health status and mortality in COPD--a review of potential interventions

COPD is prevalent in Western society and its incidence is rising in the developing world. Acute exacerbations of COPD, about 50% of which are unreported, lead to deterioration in quality of life and contribute significantly to disease burden. Quality of life deteriorates with time; thus, most of the health burden occurs in more severe disease. COPD severity and frequent and more severe exacerbations are all related to an increased risk of mortality. Inhaled corticosteroids (ICS) have similar effects on quality of life but ICS/long-acting bronchodilator combinations and the long-acting antimuscarinic tiotropium all improve health status and exacerbation rates and are likely to have an effect on mortality but perhaps only with prolonged use. Erythromycin has been shown to decrease the rate of COPD exacerbations. Pulmonary rehabilitation and regular physical activity are indicated in all severities of COPD and improve quality of life. Noninvasive ventilation is associated with improved quality of life. Long-term oxygen therapy improves mortality but only in hypoxic COPD patients. The choice of an inhaler device is a key component of COPD therapy and this requires more attention from physicians than perhaps we are aware of. Disease management programs, characterized as they are by patient centeredness, improve quality of life and decrease hospitalization rates. Most outcomes in COPD can be modified by interventions and these are well tolerated and have acceptable safety profiles.

Mesenchymal cell fate and phenotypes in the pathogenesis of emphysema

Emphysema is characterized by the destruction of alveolar parenchymal tissue and the concordant loss of lung epithelial cells, endothelial cells, and interstitial mesenchymal cells. Key features in the pathobiology of emphysema include inflammation, alveolar epithelial cell injury/apoptosis, and excessive activation of extracellular matrix (ECM) proteases. Mesenchymal cells are versatile connective tissue cells that are critical effectors of wound-repair. The excessive loss of connective tissue and the destruction of alveolar septae in emphysema suggest that the mesenchymal cell reparative response to epithelial injury is impaired. Yet, the mechanisms regulating mesenchymal cell (dys)function in emphysema remain poorly understood. We propose that mesenchymal cell fate, modulated by transforming growth factor beta-1 (TGF-beta1) and the balance of ECM proteases and antiproteases, is a critical determinant of the emphysema phenotype. We examine emphysema in the context of wound-repair responses, with a focus on the regulation of mesenchymal cell fate and phenotype. We discuss the emerging evidence supporting that genetic factors, inflammation and environmental factors, including cigarette smoke itself, collectively impair mesenchymal cell survival and function, thus contributing to the pathogenesis of emphysema.

A multi-target antisense approach against PDE4 and PDE7 reduces smoke-induced lung inflammation in mice

Background

Recent development in the field of COPD has focused on strategies aimed at reducing the underlying inflammation through selective inhibition of the phosphodiesterase type IV (PDE4) isoform. Although the anti-inflammatory and bronchodilator activity of selective PDE4 inhibitors has been well documented, their low therapeutic ratio and dose-dependent systemic side effects have limited their clinical utility. This study examined the effect of 2'-deoxy-2'-Fluoro-β-D-Arabinonucleic Acid (FANA)-containing antisense oligonucleotides (AON) targeting the mRNA for the PDE4B/4D and 7A subtypes on lung inflammatory markers, both in vitro and in vivo.

Methods

Normal human bronchial epithelial (NHBE) cells were transfected with FANA AON against PDE4B/4D and 7A alone or in combination. mRNA levels for target PDE subtypes, as well as secretion of pro-inflammatory chemokines were then measured following cell stimulation. Mice were treated with combined PDE4B/4D and 7A AON via endo-tracheal delivery, or with roflumilast via oral delivery, and exposed to cigarette smoke for one week. Target mRNA inhibition, as well as influx of inflammatory cells and mediators were measured in lung lavages. A two-week smoke exposure protocol was also used to test the longer term potency of PDE4B/4D and 7A AONs.

Results

In NHBE cells, PDE4B/4D and 7A AONs dose-dependently and specifically inhibited expression of their respective target mRNA. When used in combination, PDE4B/4D and 7A AONs significantly abrogated the cytokine-induced secretion of IL-8 and MCP-1 to near baseline levels. In mice treated with combined PDE4B/4D and 7A AONs and exposed to cigarette smoke, significant protection against the smoke-induced recruitment of neutrophils and production of KC and pro-MMP-9 was obtained, which was correlated with inhibition of target mRNA in cells from lung lavages. In this model, PDE AONs exerted more potent and broader anti-inflammatory effects against smoke-induced lung inflammation than roflumilast. Moreover, the protective effect of PDE4B/4D and 7A AON was maintained when a once-weekly treatment schedule was used.

Conclusion

These results indicate that inhaled AON against PDE4B/4D and 7A have unique effects on biomarkers that are believed to be important in the pathophysiology of COPD, which supports further development as a potential therapy in this disease.

Prediction of chronic obstructive pulmonary disease (COPD) in asthma patients using electronic medical records

OBJECTIVE

Identify clinical factors that modulate the risk of progression to COPD among asthma patients using data extracted from electronic medical records.

DESIGN

Demographic information and comorbidities from adult asthma patients who were observed for at least 5 years with initial observation dates between 1988 and 1998, were extracted from electronic medical records of the Partners Healthcare System using tools of the National Center for Biomedical Computing "Informatics for Integrating Biology to the Bedside" (i2b2).

MEASUREMENTS

A predictive model of COPD was constructed from a set of 9,349 patients (843 cases, 8,506 controls) using Bayesian networks. The model's predictive accuracy was tested using it to predict COPD in a future independent set of asthma patients (992 patients; 46 cases, 946 controls), who had initial observation dates between 1999 and 2002.

RESULTS

A Bayesian network model composed of age, sex, race, smoking history, and 8 comorbidity variables is able to predict COPD in the independent set of patients with an accuracy of 83.3%, computed as the area under the Receiver Operating Characteristic curve (AUROC).

CONCLUSIONS

Our results demonstrate that data extracted from electronic medical records can be used to create predictive models. With improvements in data extraction and inclusion of more variables, such models may prove to be clinically useful.

Systems biology coupled with label-free high-throughput detection as a novel approach for diagnosis of chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a treatable and preventable disease state, characterised by progressive airflow limitation that is not fully reversible. Although COPD is primarily a disease of the lungs there is now an appreciation that many of the manifestations of disease are outside the lung, leading to the notion that COPD is a systemic disease. Currently, diagnosis of COPD relies on largely descriptive measures to enable classification, such as symptoms and lung function. Here the limitations of existing diagnostic strategies of COPD are discussed and systems biology approaches to diagnosis that build upon current molecular knowledge of the disease are described. These approaches rely on new 'label-free' sensing technologies, such as high-throughput surface plasmon resonance (SPR), that we also describe.

Novel dry powder formulation of ovalbumin for development of COPD-like animal model: Physicochemical characterization and biomarker profiling in rats

This study was directed toward the development of novel ovalbumin dry powder inhalation system (OVA-DPI) for preparing experimental animal models of chronic obstructive pulmonary disease, with the aim of aiding the drug discovery. OVA-DPI, prepared with jet mill, showed high dispersion and emission from capsule as evaluated by cascade impactor. Based on the results from long term stability studies employing scanning electron microscopy, UPLC/ESI-MS analysis, powder X-ray diffraction and TG/DTA analyses, the OVA-DPI, stored at room temperature, was found to be stable for more than 3 years as evidenced by no significant degradation and crystal polymorphism. Intratracheal administration of OVA-DPI in OVA-sensitized rats resulted in 11-fold increase of infiltrated granulocytes, especially neutrophil, which would be characteristics of severe asthma/COPD symptoms. Of all plasma biomarkers monitored, myeloperoxidase activity and lactate dehydrogenase leakage into blood seemed to be sensitive indicators of lung injury in this model. In addition, biphasic increase of LDH was observed with peak responses at 3 and 24h after antigen challenge, suggesting that OVA-DPI could cause both acute and delayed inflammatory reactions. Upon these findings, OVA-DPI can be useful and reproducible research tool for the development of experimental asthma/COPD model.

Current cigarette smoking among in-school American youth: results from the 2004 National Youth Tobacco Survey

Background

Tobacco use is a leading cause of preventable morbidity and mortality. In the developed nations where the burden from infectious diseases is lower, the burden of disease from tobacco use is especially magnified. Understanding the factors that may be associated with adolescent cigarette smoking may aid in the design of prevention programs.

Methods

A secondary analysis of the 2004 United States National Youth Tobacco Survey was carried out to estimate the association between current cigarette smoking and selected smoking-related variables. Study participants were recruited from middle and high schools in the United States. Logistic regression analysis using SUDAAN software was conducted to estimate the association between smoking and the following explanatory variables: age, sex, race-ethnicity, peer smoking, living in the same household as a smoker, amount of pocket money at the disposal of the adolescents, and perception that smoking is not harmful to health.

Results

Of the 27727 respondents whose data were analysed, 15.9% males and 15.3% females reported being current cigarette smokers. In multivariate analysis, compared to Whites, respondents from almost all ethnic groups were less likely to report current cigarette smoking: Blacks (OR = 0.52; 95% CI [0.44, 0.60]), Asians (OR = 0.45; 95% CI [0.35, 0.58]), Hispanic (OR = 0.81; 95% CI [0.71, 0.92]), and Hawaii/Pacific Islanders (OR = 0.69; 95% CI [0.52, 0.93]). American Indians were equally likely to be current smokers as whites, OR = 0.98 [95% CI; 0.79, 1.22]. Participants who reported living with a smoker were more than twice as likely to smoke as those who did not live with a cigarette smoker (OR = 2.73; 95% CI [2.21, 3.04]). Having friends who smoked was positively associated with smoking (OR = 2.27; 95% CI [1.91, 2.71] for one friend who smoked, and OR = 2.71; 95% CI [2.21, 3.33] for two or more friends who smoked). Subjects who perceived that it was safe to smoke for one or two years were more likely to smoke than those who thought it was definitely not safe to do so. There was a dose-response relationship between age and the amount of money available to the respondents on one hand, and current smoking status on the other (p-value < 0.001).

Conclusion

We found that White non-Hispanic adolescents were as likely to be current smokers as American Indians but more likely to be smokers than all other racial/ethnic groups. Older adolescents, increase amounts of pocket money, and perception that smoking was not harmful to health. The racial/ethnic differences in prevalence of smoking among America youth deserve particular exploration.

The natural history of chronic airflow obstruction revisited: an analysis of the Framingham offspring cohort

RATIONALE

Understanding normal lung development and aging in health and disease, both in men and in women, is essential to interpreting any therapeutic intervention.

OBJECTIVES

We aimed to describe lung function changes in healthy never-smoking males and females, from adolescence to old age, and to determine the effects of smoking and those derived from quitting.

METHODS

Prospective cohort study within all participants of the Framingham Offspring cohort who had two or more valid spirometry measurements during follow-up (n = 4,391; age range at baseline 13 to 71 yr), with a median follow-up time of 23 years.

MEASUREMENTS AND MAIN RESULTS

To best fit the curves describing FEV(1) changes with age to raw data, we used a generalized additive model with smooth terms and incorporating the subject-specific (longitudinal) random effects. We found that: (1) healthy never-smoker females achieve full lung growth earlier than males, and their rate of decline with age was slightly, but not significantly, lower; (2) smoking increases the rate of lung function decline, both in males and in females; (3) there is a range of susceptibility to the effects of smoking. The presence of respiratory symptoms at baseline and/or a respiratory diagnosis during follow-up appears to identify a group of susceptible smokers; and (4) quitting smoking has a beneficial effect at any age, but it is more pronounced in earlier quitters.

CONCLUSIONS

Lung function changes from adolescence to old age differ in males and females, smoking has similar deleterious effects in both sexes, and quitting earlier is better.

Tiotropium and exercise training in COPD patients: effects on dyspnea and exercise tolerance

BACKGROUND

Exercise training improves exercise tolerance in chronic obstructive pulmonary disease (COPD). Tiotropium 18 microg once daily induces sustained bronchodilation throughout the day and reduces hyperinflation, one of the pathophysiological factors contributing to exertional dyspnea in COPD patients.

AIM

To determine whether tiotropium enhances the effects of exercise training in patients with COPD.

DESIGN

Multicenter, 25 week randomized, double-blind, placebo-controlled, parallel-group study.

SETTING

Twelve Italian Pulmonary Units practicing pulmonary rehabilitation.

PATIENTS AND INTERVENTION

Two hundred thirty four COPD patients (196 males; mean age: 67.4 +/- 7.6; forced expiratory volume at 1 second (FEV1): 41.4 +/- 13.0% predicted) were randomised to tiotropium 18 microg or placebo inhalation capsules taken once daily. Both groups underwent a 8 week pulmonary rehabilitation program (PR) consisting of 3 exercise training session per week.

MEASUREMENTS

Baseline, at the end of PR and after 12 weeks, patients completed pulmonary function testing, six minute walking test (6MWT), the Baseline and Transition Dyspnea Index (BDI and TDI), and the St. George's Respiratory Questionnaire (SGRQ).

RESULTS

Relative to placebo, tiotropium had larger trough and post-study drug FEV1 responses on all test days. At the end of and 12 weeks following PR, patients on tiotropium showed no statistically significant differences in 6MWT compared to patients on placebo. Compared to the period immediately prior to PR, the mean improvement in 6MWT was only 29.7 meters (7.1%) for the combined cohort. Mean TDI focal scores at the end of PR were 3.60 for tiotropium and 2.25 for placebo (p < 0.01). At 12 weeks after PR, TDI focal scores were 2.71 for tiotropium and 2.11 for placebo (p = 0.16). Reduction in all four SGRQ component scores, indicating an improvement in health-related quality of life, was observed for the tiotropium group over the duration of the study compared to placebo but the differences were not statistically significant. During the study period, there were fewer exacerbations and exacerbation days in the tiotropium group.

CONCLUSION

Although significant improvements were observed with perceived dyspnea, compared to placebo, the addition of tiotropium to pulmonary rehabilitation did not improve the 6MWT.

Treatment of mild chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is an epidemic in many parts of the world. Most patients with COPD demonstrate mild disease. The cornerstone of management of mild disease is smoking cessation, which is the only proven intervention to relieve symptoms, modify its natural history and reduce mortality. For asymptomatic patients, it is the only required therapy. Short-acting bronchodilators can be added on an as needed basis for those with intermittent symptoms and regularly for those with persistent symptoms. Long-acting bronchodilators can be substituted for those who remain symptomatic despite regular use of short-acting bronchodilators. Inhaled corticosteroids do not modify the natural history of COPD and as such cannot be recommended as standalone therapy for mild COPD. However, for patients with refractory and intractable symptoms, they may be used in combination with long-acting beta-2 agonists. Influenza and pneumococcal vaccination and pulmonary rehabilitation are other therapies that may be considered for select patients with mild disease. In this paper, we summarize the current standard of care for patients with mild COPD.

Treatment of respiratory failure in COPD

Patients with advanced COPD and acute or chronic respiratory failure are at high risk for death. Beyond pharmacological treatment, supplemental oxygen and mechanical ventilation are major treatment options. This review describes the physiological concepts underlying respiratory failure and its therapy, as well as important treatment outcomes. The rationale for the controlled supply of oxygen in acute hypoxic respiratory failure is undisputed. There is also a clear survival benefit from long-term oxygen therapy in patients with chronic hypoxia, while in mild, nocturnal, or exercise-induced hypoxemia such long-term benefits appear questionable. Furthermore, much evidence supports the use of non-invasive positive pressure ventilation in acute hypercapnic respiratory failure. It application reduces intubation and mortality rates, and the duration of intensive care unit or hospital stays, particularly in the presence of mild to moderate respiratory acidosis. COPD with chronic hypercapnic respiratory failure became a major indication for domiciliary mechanical ventilation, based on pathophysiological reasoning and on data regarding symptoms and quality of life. Still, however, its relevance for long-term survival has to be substantiated in prospective controlled studies. Such studies might preferentially recruit patients with repeated hypercapnic decompensation or a high risk for death, while ensuring effective ventilation and the patients’ adherence to therapy.

Treating patients with respiratory disease who smoke

The high prevalence of cigarette smoking in patients with respiratory disease puts them at risk of developing clinically important drug interactions. Cigarette smoking reduces the therapeutic response to certain drugs such as theophyllines through the induction of hepatic cytochrome P450 isoenzymes. Smokers with asthma and patients with COPD have reduced sensitivity to corticosteroids, possibly due to non-eosinophilic airway inflammation, altered glucocorticoid receptor activity or reduced histone deacetylase activity. Although all smokers should be encouraged to stop smoking, there is limited information on the influence of smoking cessation on the therapeutic and anti-inflammatory effects of a number of the drugs used in the treatment of respiratory disease.

Office spirometry can improve the diagnosis of obstructive airway disease in primary care setting

INTRODUCTION

Spirometry may reveal pre-clinical abnormal airway function in asymptomatic subjects and allow a better definition of severity in clinically diagnosed asthma and COPD. The hypothesis of this study was that telespirometry might increase the diagnostic accuracy of asthma and COPD.

METHODS

In the Italian "Alliance" study, 638 general practitioners (GPs) were trained to perform telespirometry and were asked to enroll the following categories of subjects: (a) current or ex-smokers without respiratory symptoms; (b) subjects with respiratory symptoms but without a pre-existing diagnosis of asthma or COPD; (c) subjects with a pre-existing clinical diagnosis of asthma; and (d) subjects with a pre-existing clinical diagnosis of COPD. Subjects completed a case report form (CRF) and performed telespirometry in the GP's office. Traces were sent by telephone to a Telespirometry Central Office, where they were interpreted by a pulmonary specialist, according to appropriately defined criteria. The results were returned in real time to the GP.

RESULTS

Overall, 9312 subjects were recruited and 7262 (78%) performed an acceptable telespirometric examination and the CRF. In the asymptomatic group, 340/1437 (24%) of the telespirometries were abnormal (147 with moderate-to-severe airway obstruction, i.e. FEV(1) <80% of predicted). Among symptomatic subjects, 1433/3725 (38%) had abnormal telespirometries (682 with moderate-to-severe obstruction). Of the asthmatic subjects, 336/1285 (26%) had moderate-to-severe airway obstruction, while telespirometry was normal in 184/815 (23%) of the COPD group.

CONCLUSION

Telespirometry, performed in a GP's office, can aid the diagnosis of obstructive airway diseases and could help GPs to better manage airway obstruction.

Bacteria challenge in smoke-exposed mice exacerbates inflammation and skews the inflammatory profile

RATIONALE

The pathogenesis of chronic obstructive pulmonary disease is associated with acute episodes of bacterial exacerbations. The most commonly isolated bacteria during episodes of exacerbation is nontypeable Haemophilus influenzae (NTHI).

OBJECTIVES

In this study, we investigated the in vivo consequences of cigarette smoke exposure on the inflammatory response to an NTHI challenge.

METHODS

C57BL/6 and BALB/c mice were exposed to cigarette smoke for 8 weeks and subsequently challenged intranasally with NTHI.

MEASUREMENTS AND MAIN RESULTS

We observed increased pulmonary inflammation and lung damage in cigarette smoke-exposed NTHI-challenged mice as compared with control NTHI-challenged mice. Furthermore, although NTHI challenge in control mice was marked by increases in tumor necrosis factor-alpha, IL-6, MIP-2, and KC/GROalpha, NTHI challenge in cigarette smoke-exposed mice led to a prominent up-regulation of a different subset of inflammatory mediators, most notably MCP-1, -3, and -5, IP-10, and MIP-1gamma. This skewed inflammatory mediator expression was also observed after ex vivo NTHI stimulation of alveolar macrophages, signifying their importance to this altered response. Importantly, corticosteroids attenuated inflammation after NTHI challenge in both cigarette smoke-exposed and control mice; however, this was associated with significantly increased bacterial burden.

CONCLUSIONS

Collectively, these data suggest that cigarette smoke exacerbates the inflammatory response to a bacterial challenge via skewed inflammatory mediator expression.

Traffic-related air pollution associated with prevalence of asthma and COPD/chronic bronchitis. A cross-sectional study in Southern Sweden

Background

There is growing evidence that air pollution from traffic has adverse long-term effects on chronic respiratory disease in children, but there are few studies and more inconclusive results in adults. We examined associations between residential traffic and asthma and COPD in adults in southern Sweden. A postal questionnaire in 2000 (n = 9319, 18–77 years) provided disease status, and self-reported exposure to traffic. A Geographical Information System (GIS) was used to link geocoded residential addresses to a Swedish road database and an emission database for NOx.

Results

Living within 100 m of a road with >10 cars/minute (compared with having no heavy road within this distance) was associated with prevalence of asthma diagnosis (OR = 1.40, 95% CI = 1.04–1.89), and COPD diagnosis (OR = 1.64, 95%CI = 1.11–2.4), as well as asthma and chronic bronchitis symptoms. Self-reported traffic exposure was associated with asthma diagnosis and COPD diagnosis, and with asthma symptoms. Annual average NOx was associated with COPD diagnosis and symptoms of asthma and chronic bronchitis.

Conclusion

Living close to traffic was associated with prevalence of asthma diagnosis, COPD diagnosis, and symptoms of asthma and bronchitis. This indicates that traffic-related air pollution has both long-term and short-term effects on chronic respiratory disease in adults, even in a region with overall low levels of air pollution.

[Pathogenesis of chronic obstructive pulmonary disease]

Chronic obstructive pulmonary disease (COPD) is a respiratory disease characterized by permanent and progressive airway obstruction. Cigarette smoking is the main cause responsible for COPD although only 15 to 25 % of smokers develop COPD. Mechanisms underlying COPD pathogenesis are not fully understood. Structural abnormalities in small airways (bronchioles < 2mm in diameter) are the main determinants of airway obstruction; obstruction of these bronchioles is related to increase in airway wall thickness (associated with peribronchiolar fibrosis) and to plugging by mucus exudates. Alveolar wall destruction (emphysema) also contributes to airway obstruction and to gas exchange abnormalities. Current knowledge related to molecular and cellular mechanisms responsible for these structural modifications are reviewed.

Smoking and chronic obstructive pulmonary disease (COPD). Parallel epidemics of the 21 century

One hundred million deaths were caused by tobacco in the 20(th) century, and it is estimated that there will be up to one billion deaths attributed to tobacco use in the 21(st) century. Chronic obstructive pulmonary disease (COPD) is rapidly becoming a global public health crisis with smoking being recognized as its most important causative factor. The most effective available treatment for COPD is smoking cessation. There is mounting evidence that the rate of progression of COPD can be reduced when patients at risk of developing the disease stop smoking, while lifelong smokers have a 50% probability of developing COPD during their lifetime. More significantly, there is also evidence that the risk of developing COPD falls by about half with smoking cessation. Several pharmacological interventions now exist to aid smokers in cessation; these include nicotine replacement therapy, bupropion, and varenicline. All pharmacotherapies for smoking cessation are more efficacious than placebo, with odds ratios of about 2. Pharmacologic therapy should be combined with nonpharmacologic (behavioral) therapy. Unfortunately, despite the documented efficacy of these agents, the absolute number of patients who are abstinent from smoking at 12 months of follow-up is low.

The nature and causes of chronic obstructive pulmonary disease: a historical perspective. The Christie Lecture 2007, Chicago, USA

Chronic obstructive pulmonary disease (COPD) is the currently favoured name for the diseases formerly known as emphysema and bronchitis. COPD has been recognized for more than 200 years. Its cardinal symptoms are cough, phlegm and dyspnea, and its pathology is characterized by enlarged airspaces and obstructed airways. In the 19th century, the diagnosis of COPD depended on its symptoms and signs of a hyperinflated chest, and reduced expiratory breath sounds. The airflow obstruction evident on spirometry was identified in that century, but did not enter into clinical practice. Bronchitis, and the mechanical forces required to overcome its obstruction, was believed to be responsible for emphysema, although the inflammation present was recognized. The causes of bronchitis, and hence emphysema, included atmospheric and domestic air pollution, as well as dusty occupations. Cigarette smoking only became recognized as the dominant cause in the 20th century. The lessons learned of the risks for COPD in 19th-century Britain are very pertinent to the world today.