Cotton dust lung diseases

Evaluation of progressive pulmonary fibrosis in non-idiopathic pulmonary fibrosis-interstitial lung diseases: a cross-sectional study

BACKGROUND

Progressive pulmonary fibrosis is the symptomatic, physiological, and radiological progression of interstitial lung diseases. The aim of this study was to examine the relationship between progressive pulmonary fibrosis and demographic characteristics and to evaluate the effect on clinical outcomes and mortality.

METHODS

This cross-sectional study included 221 patients diagnosed with non-idiopathic pulmonary fibrosis interstitial lung diseases who were followed in the last 5 years. Patient symptoms, clinical, radiological, and demographic data were examined. Risk factors for the development of progressive pulmonary fibrosis and the relationship with clinical outcomes and mortality were examined.

RESULTS

Of the patients, 33.0% (n = 73) had fibrotic idiopathic nonspecific interstitial pneumonia (iNSIP), 35.7% (n = 79) had fibrotic hypersensitivity pneumonia (HP), 18.1% (n = 40) had fibrotic connective tissue disease (CTD) interstitial lung diseases (ILD), and 13.1% (n = 29) had postinfectious fibrotic ILD. The progressive pulmonary fibrosis development rates of the subtypes were 46.5% iNSIP (n = 34), 86.0% fibrotic HP (n = 68), 42.5% fibrotic CTD-ILD (n = 17), and 20.7% postinfectious ILD (n = 6). The presence of progressive pulmonary fibrosis was associated with the development of respiratory failure and mortality (odds ratio [OR]: 2.70, 95% CI: 1.04-7.05 and OR: 2.13, 95% CI: 1.23-3.69). Progressive pulmonary fibrosis development was higher in hypersensitivity pneumonia patients with farmer's lung (OR: 5.06, 95% CI: 1.02-25.18).

CONCLUSION

Progressive pulmonary fibrosis was more prevalent in older patients. Farming was an important risk factor in the development of hypersensitivity pneumonia-progressive pulmonary fibrosis. Respiratory failure and mortality were higher in those who developed progressive pulmonary fibrosis.

Respiratory symptoms and pulmonary function impairment among textile industry workers in Alexandria, Egypt

Occupational exposure to cotton dust is still an important cause of respiratory problems in textile workers particularly in less developed countries like Egypt. Evaluate respiratory symptoms and diseases, and pulmonary function pattern among Egyptian textile workers. Cross sectional comparative study was conducted from December 2019 to September 2020 in a textile factory in Egypt; 364 male workers (184 cotton dust exposed workers, and 180 unexposed workers) were included. Participants were subjected to an interviewing questionnaire, British Medical Research Council questionnaire, anthropometric measurements, pulmonary function tests, and byssinosis grading format. Descriptive and analytic statistics were conducted. Chronic cough, phlegm production, and shortness of breath grade I, II and III were more reported in cotton dust exposed workers than unexposed workers (P#x003C;0.01, P#x003C;0.01, and P=0.02, respectively). Prevalence of chronic bronchitis was significantly higher among cotton dust exposed workers (12%) than unexposed workers (3.9%) (P#x003C;0.01). The mean percent predicted values of lung function indices reflecting large-1irway function (VC, FVC, FEV1, FEV1%, PEFR, and FEF75) were significantly lower in cotton dust exposed workers (P#x003C;0.01). Prevalence of byssinosis was 22.8%. Workers with byssinosis had significantly higher prevalence of respiratory symptoms, chronic bronchitis, cross-shift reduction in PEFR and significant decrease in mean percent predicted values of FVC, FEV1, PEFR, FEF75, and FEF50 than workers without byssinosis. This study revealed a substantial association between cotton dust exposure at work and respiratory symptoms and morbidity. Regular measurement of cross shift change in PEFR is recommended among exposed workers for early diagnosis of byssinosis.

miR-7-5p Antagomir Protects Against Inflammation-Mediated Apoptosis and Lung Injury via Targeting Raf-1 In Vitro and In Vivo

Exacerbated inflammation and apoptosis are considered upstream events associated with acute lung injury (ALI). microRNAs are critical regulators of genes responsible for inflammation and apoptosis and are considered potential therapeutic targets for ameliorating ALI. This study was undertaken to uncover the role of miR-7-5p in LPS-induced lung injury. A LPS-induced inflammation model was established using BEAS-2B cells and C57BL/6 mice. Bioinformatics analysis and the luciferase reporter assay confirmed that Raf-1 is a target of miR-7-5p and that its expression was inversely correlated with expression of proinflammatory markers and miR-7-5p, whereas miR-7-5p inhibition in vitro led to subsequent restoration of Raf-1 expression and prevention of apoptosis. Intranasal (i.n.) administration of antagomir using the C57BL/6 mouse model further confirmed that miR-7-5p inhibition suppresses LPS-induced inflammation and apoptosis via modulating the miR-7-5p/Raf-1 axis. Our findings indicate that blocking miR-7-5p expression by antagomir protects mice from LPS-induced lung injury by suppressing inflammation and activation of mitochondria-mediated survival signalling. In conclusion, our findings demonstrate a previously unknown pathophysiological role of miR-7-5p in the progression of ALI, and targeted i.n. administration of miR-7-5p antagomir could aid in the development of potential therapeutic strategies against lung injury.

Analysis of lung function and respiratory symptoms in brass/metal industrial workers of Moradabad, Uttar Pradesh, India

Background

The job demands of some of the industries have been reported to be hazardous to the health and safety of workers. Workplace environmental hazards or occupational hazards are a globally major cause of disability and mortality among the working population. The present study was done to analyze the effect of exposure to metal dust on pulmonary function and respiratory symptoms.

Materials and Methods

The study population selected as cases were 200 male mill workers working for at least 1-year duration (direct exposure) in the age group of 20-50 years, and controls were 200 age- and gender-matched male participants without any history of occupational or environmental exposure. A complete history was taken. Spirometry was done. Spirometric parameters studied were forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), ratio of FEV1 and FVC, and peak expiratory flow rate (PEFR). The spirometry data and baseline characteristics of the participants were compared using unpaired t-test.

Results

The mean age of the participants of the study group and the control group was 42.3 years and 44.1 years, respectively. The majority of the study population belonged to the age group of 41-50 years. The mean FEV1 value among participants of the study group and control group was 2.69 and 2.13, respectively. The mean FVC value among participants of the study group and control group was 3.18 and 3.63, respectively. The mean FEV1/FVC value among participants of the study group and control group was 84.59% and 86.22%, respectively. The mean PEFR value among the study group and control group was 7.78 and 8.67, respectively. While analyzing statistically, mean lung functional tests were significantly lowered among the study group. About 69.5% of the participants of the study group thought it to be essential for making safety measures a necessity.

Conclusion

The present study concluded that mean lung functional tests were significantly lowered among the study group. Despite the use of face mask, lung function abnormality was present in mill workers.

Registered health problems and demographic profile of integrated textile factory workers in Ethiopia: a cross-sectional study

BACKGROUND

Textile and garment factories are growing in low and middle-income countries as worldwide demand for inexpensive clothing increases each year. These integrated textile and garment production factories are often built-in areas with few workplaces and environmental regulations, and employees can be regularly exposed to workplace hazards with little regulatory oversight. Consequently, workers' health may be significantly affected due to long term exposure to hazards. This study describes registered health problems and their association to work-related and personal factors among workers in integrated textile factories in Ethiopia.

METHODS

Institution-based cross-sectional study design was employed for this analysis. A one-year recording of worker's clinical diagnoses (between March 2016 and February 2017) was gathered from the factory clinics of three integrated textile factories. Clinical diagnosis data was obtained as factory workers visited the clinics if feeling unwell. Sociodemographic characteristics and work-related information were obtained from the factory's human resource departments. The sociodemographic and clinical diagnosis statuses of 7992 workers were analyzed. The association between the registered diagnoses and workplace factors (work in textile production, garment production and support process) and personal factors (age, sex and educational status) were studied using logistic regression analysis.

RESULTS

The average employee age and years of service were 40 years and 11 years respectively. 60% of workers were females, comprising of 4778 women. 66% of all workers (5276) had 27,320 clinical diagnoses. In total, this caused 16,993 absent working days due to sick leave. Respiratory diseases (34%) and musculoskeletal disorders (29%) were the most prevalent diagnoses, while bodily injuries were the cause of most work absences. Work department, sex and educational status are variables that were most significantly associated with higher prevalence of disease groups.

CONCLUSIONS

About two-thirds of the integrated textile factory workers were diagnosed with different types of disease. The textile and garment production department workers were affected at a greater rate than the support process workers, indicating that some diseases may be related to workplace exposure. Further study should investigate rare chronic diseases such as cancer, heart diseases, renal diseases and diabetes.

Health disorders and safety measures among workers in Tanta Flax and Oil Company, Egypt

Flax industry has an adverse effect on health status of exposed workers especially in developing countries with lack of appropriate safety measures to identify the health hazards, health disorders among workers in flax and oil company, and to assess the applied safety measures in the factory. A cross sectional study was conducted in Tanta Flax and Oil Company in Egypt. The company includes eight factories which are divided into four departments according to the manufacturing end products. The study was conducted from August 2018 to December 2019 on 353 workers out of 400 workers. An interview questionnaire and clinical medical examination were done to assess the health status of exposed workers. Check list from occupational safety and health administration (OSHA) standards was filled by researcher to check safety measures in work place environment. Respiratory manifestations were detected in 65% of the examined workers in flax manufacturing departments while allergic manifestations were more obvious in formaldehyde factory department. Approximately one quarter of workers complained that personal protective equipment's are not available. Regarding the mask for dust, nearly half (44.5%) of the workers rarely used them, and only 7.1% always use them. Byssinosis was obvious among workers in flax manufacturing and particle board manufacturing department with statistically significant differences between the four departments, in which 36.9% and 24.1% of workers in these two departments suffered from chest tightness, respectively. The safety measures were inadequate in flax manufacturing departments and to somewhat sufficient in formaldehyde factory department. Most of exposed workers had inadequate health status due to lack of standard safety measures. Therefore, periodic medical examination should be done regularly with investigation of pulmonary functions of exposed workers with application of high level of safety measure standards in the work place environment.

A guide to crystal-related and nano- or microparticle-related tissue responses

Crystals and nano- and microparticles form inside the human body from intrinsic proteins, minerals, or metabolites or enter the body as particulate matter from occupational and environmental sources. Associated tissue injuries and diseases mostly develop from cellular responses to such crystal deposits and include inflammation, cell necrosis, granuloma formation, tissue fibrosis, and stone-related obstruction of excretory organs. But how do crystals and nano- and microparticles trigger these biological processes? Which pathomechanisms are identical across different particle types, sizes, and shapes? In addition, which mechanisms are specific to the atomic or molecular structure of crystals or to specific sizes or shapes? Do specific cellular or molecular mechanisms qualify as target for therapeutic interventions? Here, we provide a guide to approach this diverse and multidisciplinary research domain. We give an overview about the clinical spectrum of crystallopathies, about shared and specific pathomechanisms as a conceptual overview before digging deeper into the specialty field of interest.

Cotton Dust Exposure and Respiratory Disorders among Textile Workers at a Textile Company in the Southern Part of Benin

The textile industry sector occupies a prominent place in the economy of Benin. It exposes workers to several occupational risks, including exposure to cotton dust. To assess the effect of exposure to cotton dust on the health of workers, this study was initiated and conducted in a Beninese cotton industry company. The objective of the study was to evaluate the respiratory disorders among the textile workers exposed to cotton dust and the cross-sectional study involved 656 subjects exposed to cotton dust and 113 non-exposed subjects. The methods used are mainly based on a survey using a questionnaire of organic dust designed by the International Commission of Occupational Health (ICOH); and on the measures of lung function parameters (FEV₁ and FVC). The main results of the different analyzes revealed that subjects exposed to cotton dust have more respiratory symptoms than unexposed subjects (36.9% vs. 21.2%). The prevalence of chronic cough, expectorations, dyspnoea, asthma and chronic bronchitis are 16.8%, 9.8%, 17.3%, 2.6%, and 5.9% respectively among the exposed versus 2.6%, 0.8%, 16.8%, 0% and 0.8% among the unexposed subjects. The prevalence of byssinosis is 44.01%.The prevalence of symptoms is dependent on the sector of activity and the age of the subject. These results should encourage medical interventions and technical prevention especially since the textile industry occupies an important place in the Benin's economy.

Occupational bronchiolitis induced by cotton dust exposure in a nonsmoker

The most well-known disease caused by cotton dust is byssinosis though it is also associated with chronic obstructive airways disease, and very rarely, interstitial lung disease. Obliterative bronchiolitis has never been reported in this setting. We report a 63-year-old, nonsmoker male, who presented with complaints of cough and exertional dyspnoea for 10 years. He had worked in textile industry for 35 years and symptoms had persisted even after quitting. Examination revealed prolonged expiration with expiratory wheeze, and pulmonary function tests revealed severe airflow limitation with air trapping and impaired diffusion capacity. Arterial blood gas analysis showed type I respiratory failure. A high resolution computed tomogram of the chest showed bilateral centrilobular nodules with tree-in-bud pattern and areas of air trapping. A diagnosis of obliterative bronchiolitis induced by cotton dust exposure was established on the basis of the occupational history and the characteristic radiological signs.

Occupational exposure to textile dust increases the risk of rheumatoid arthritis: results from a Malaysian population-based case-control study

Objectives

Lung exposures including cigarette smoking and silica exposure are associated with the risk of rheumatoid arthritis (RA). We investigated the association between textile dust exposure and the risk of RA in the Malaysian population, with a focus on women who rarely smoke.

Methods

Data from the Malaysian Epidemiological Investigation of Rheumatoid Arthritis population-based case–control study involving 910 female early RA cases and 910 female age-matched controls were analysed. Self-reported information on ever/never occupationally exposed to textile dust was used to estimate the risk of developing anti-citrullinated protein antibody (ACPA)-positive and ACPA-negative RA. Interaction between textile dust and the human leucocyte antigen DR β-1 (HLA-DRB1) shared epitope (SE) was evaluated by calculating the attributable proportion due to interaction (AP), with 95% CI.

Results

Occupational exposure to textile dust was significantly associated with an increased risk of developing RA in the Malaysian female population (OR 2.8, 95% CI 1.6 to 5.2). The association between occupational exposure to textile dust and risk of RA was uniformly observed for the ACPA-positive RA (OR 2.5, 95% CI 1.3 to 4.8) and ACPA-negative RA (OR 3.5, 95% CI 1.7 to 7.0) subsets, respectively. We observed a significant interaction between exposure to occupational textile dust and HLA-DRB1 SE alleles regarding the risk of ACPA-positive RA (OR for double exposed: 39.1, 95% CI 5.1 to 297.5; AP: 0.8, 95% CI 0.5 to 1.2).

Conclusions

This is the first study demonstrating that textile dust exposure is associated with an increased risk for RA. In addition, a gene–environment interaction between HLA-DRB1 SE and textile dust exposure provides a high risk for ACPA-positive RA.

A study of respiratory function among the workers engaged in ginning processes

Background:

Known respiratory health effects of exposure to cotton dust are mainly altered pulmonary function findings and symptom of chest tightness. A number of studies have been carried out all over the world to enumerate and evaluate the health effects of cotton dust exposed workers in different processes. However, such studies carried out in ginning industry especially in Indian context are scanty.

Objectives:

This study was initiated to explore occupational and morbidity details and respiratory functional status of the exposed workers as well as to investigate across the working shift pulmonary function changes.

Materials and Methods:

A cross-sectional study was conducted including workers from ginning units where principal exposure is from cotton dust. All the workers of the selected ginning units were subjected to an interview with a predesigned questionnaire to collect occupational and medical history, clinical examination and pulmonary function test.

Results:

In this present study, no cross-shift significant change in relation to PEFR and FEV₁ values is observed. However, chronic effect on lung function is observed in a few subjects and declining trend of values was observed with increasing job duration as well as age of workers and among smokers. Other health problems among these subjects were backache and joint pain.

Conclusions:

Studies on cotton textile workers have shown both cross-shift and chronic decline of values. In this study on ginning workers, chronic effect only is observed. This difference of observation may be explained by different nature of exposure in case of ginning. This study recommends regular periodic clinical examination, lung function test and monitoring of dust, gram-negative bacteria and endotoxins in such workplaces.

Spectrum of high resolution computed tomography findings in occupational lung disease: experience in a tertiary care institute

Objective:

To study the spectrum of high resolution computed tomography (HRCT) findings in occupational lung disease in industrial workers and to assess the utility of International classification of HRCT for occupational and environmental respiratory diseases (ICHOERD).

Materials and Methods:

Retrospective analysis of radiological data (radiographs and computed tomography chest scans) gathered over a period of 3 years (January 2010- December 2012) of industrial workers in an organised sector who presented with respiratory complaints. The HRCT findings were evaluated using ICHOERD.

Results:

There were 5 females and 114 males in the study, with a mean age of 49 years. These workers were exposed to different harmful agents including silica, asbestos, cotton dust, metal dust, iron oxide, organic dust, rubber fumes, plastic fumes, acid fumes, and oil fumes. There were 10 smokers in the study. The radiograph of chest was normal in 53 patients. 46% of these normal patients (21.8% of total) demonstrated positive findings on HRCT. When the radiograph was abnormal, HRCT provided more accurate information and excluded the other diagnosis. The HRCT findings were appropriately described using the ICHOERD. Bronchiectasis was the most common finding (44.5%) with mild central cylindrical bronchiectasis as the most common pattern. Pleural thickening was seen in 41 patients (34.5%). Enlarged hilar or mediastinal lymphnodes were seen in 10 patients (8.4%) with egg-shell calcification in 1 patient exposed to silica. Bronchogenic carcinoma was seen in 1 patient exposed to asbestos.

Conclusions:

Occupational lung disease is a common work related condition in industrial workers even in the organized sector. Though chest radiograph is the primary diagnostic tool, HRCT is the undisputed Gold Standard for evaluation of these patients. Despite the disadvantage of radiation exposure, low dose CT may serve as an important tool for screening and surveillance. The ICHOERD is a powerful and reliable tool not only for diagnosis, but also for quantitative and analytical measurement of disease, thereby contributing to assessing the medical epidemiology of lung disease. It should always be used while evaluating HRCT of a patient with occupational lung disease.

Longitudinal pulmonary functional loss in cotton textile workers: a 5-year follow-up study

BACKGROUND

Occupational exposure to cotton dust causes several diseases affecting the lungs, but only limited information is available on effects of long-term exposure. In this study, we aimed to evaluate longitudinal changes in selected parameters of pulmonary function in textile workers.

MATERIAL AND METHODS

This prospective cohort study began with 196 textile workers in 2006 and was completed in 2011 with 49 workers. We used standardized tests for pulmonary function on participants on the first day of the workweek in June of 2006 and 2011. Environmental samples of cotton dust were gathered with a vertical elutriator. Loss of pulmonary function was assessed based on gender and smoking status.

RESULTS

The mean number of years participants worked in the textile factory was 7.61 ± 1.83 years, and the mean age was 35.3+5.8 years. The annual FEV1 loss of all workers was 53.2 ml, giving a ratio of annual FEV1 loss to baseline FEV1 of 1.4%. Pulmonary function parameters of all participants in 2011 were significantly lower than those in 2006 (for all, p<0.05). In both surveys, pulmonary function in current smokers was lower, but this difference was not significant (p>0.05).

CONCLUSIONS

This study provides the first data on pulmonary functional loss in Turkish textile workers and supports the findings of other cohort studies that workers with long-term exposure to cotton dust may lose some pulmonary function. The ratio of annual FEV1 loss to baseline FEV1 appears to be a more accurate and comparable method than annual FEV1 loss for evaluating pulmonary functional loss.

Occupational chronic obstructive pulmonary disease: an update

Chronic obstructive pulmonary disease represents a major cause of morbidity and mortality in industrialized and nonindustrialized countries. Although tobacco use remains the main factor associated with development of the disease, occupational risk factors represent an important and preventable cause. The most common occupationally related factors include exposure to organic dusts, metallic fumes, and a variety of other mineral gases and/or vapors. This article summarizes the literature on the subject and provides an update of the most recent advances in the field.

Occupation and chronic obstructive pulmonary disease (COPD)

INTRODUCTION

There is growing interest in preventable, non-smoking causes of chronic obstructive pulmonary disease (COPD), among which are chronic exposures to respiratory irritants in the workplace.

SOURCES OF DATA

Reviews of occupational COPD in specific occupations and industries and in general populations; supplemented with other or more recently published material.

AREAS OF AGREEMENT

There is good evidence for an increased risk of COPD from certain specific exposures (coal mine dust, silica, welding fume, textile dust, agricultural dust, cadmium fume).

AREAS OF CONTROVERSY

Less clear is the causal role of non-specific dusts or fumes/gases in general populations where the available literature is notably uncritical.

GROWING POINTS

Other specific exposures, such as diesel fume; interactions between specific exposures and cigarette smoking; the development of safe working limits.

AREAS TIMELY FOR DEVELOPING RESEARCH

Occupations with large numbers of exposed employees, particularly in low-income countries.

Reduction in cotton dust concentration does not totally eliminate respiratory health hazards: the Greek study

A number of epidemiological studies have shown that byssinosis is associated with exposure to high levels of cotton dust. In this first survey, the prevalence of respiratory symptoms in cotton workers under low concentration of cotton dust was investigated. A respiratory questionnaire consisting of 47 questions was given to 443 cotton workers. Their lung function was measured with spirometry. Breathing zone cotton dust concentration was measured by personal samplers and static sampling was used to define the level of the work area concentration. Workers with abnormalities in the pulmonary function parameters, including forced expiratory volume in 1 second (FEV₁), forced vital capacity (FVC) and peak expiratory flow rate (PEFR), were 5.9%. In this group of operatives 7.7% had symptoms compatible with byssinosis, 65.4% of them were smokers, 69.2% of them had symptoms of allergic rhinitis, while 72.2% of them were smokers. Asthma, which appeared after the age of 30, was reported by 57.7%, while 60% of them were smokers. Mean breathing zone cotton dust concentration was 0.16 mg/m³ and the mean work area cotton dust concentration 0.14 mg/m³. Despite the reduction in cotton dust concentration, byssinosis symptoms, allergic rhinitis, asthma and impaired pulmonary function are the most common findings in our cotton workers depending on the duration of exposure, whether they are smokers or not and the nature of the cotton dust.

[Role of indoor endotoxins in asthma symptoms]

INTRODUCTION

Endotoxin is a collective term designating a characteristic group of chemical constituents of the outer membrane of Gram negative bacteria, the lipopolysaccharides (LPS).

BACKGROUND

LPS provocation tests in healthy subjects (50 microg) induce asthma-like airflow obstruction with a neutrophilic inflammatory influx, similar to reactions observed in non-atopic asthma. Asthmatic subjects show the same reaction with smaller doses of LPS (20 microg), revealing higher sensitivity to LPS than normal subjects. Low levels (2 microg) of LPS do not induce either airflow obstruction or bronchial hyperreactivity. Among exposed workers, particularly in agriculture, endotoxin is the most significant component of the bioaerosol that is associated with airway disease. In clinical studies, exposure to LPS is associated with severe asthma. Conversely, epidemiological studies, in both urban and rural areas, assessing the relationship between exposure to LPS and asthma and asthma- related symptoms are inconsistent.

PERSPECTIVES

Longitudinal epidemiological studies, especially in farm children, may confirm the putative protective effects of LPS with respect to atopic asthma.

CONCLUSION

Exposure to indoor LPS is frequently associated with asthma and asthma-like symptoms in current studies. Their definitive role needs to be confirmed by birth cohort studies currently under way that should define the controversial protective effect of LPS with respect to atopic asthma in farming populations.

Acute pulmonary lipopolysaccharide tolerance decreases TNF-alpha without reducing neutrophil recruitment

Pulmonary LPS exposure plays a key role in exacerbation of lung diseases such as chronic obstructive pulmonary disease and asthma. However, little is known about the effects of repeated LPS exposure in the lung microenvironment. We have developed a novel murine model of pulmonary LPS tolerance induced by intratracheal (i.t.) administration of LPS. First, we show that pulmonary LPS exposure does not induce whole-body refractoriness to systemic LPS, because i.t. administration followed by i.p. administration did not decrease plasma TNF-alpha. However, a local refractory state can be induced with two i.t. LPS exposures. Pulmonary LPS tolerance was induced by i.t. administration of 100 ng LPS at time 0 and 48 h. Nontolerant mice received PBS at time 0 and LPS at 48 h. Bronchoalveolar lavage levels of TNF-alpha were significantly attenuated in tolerant mice vs nontolerant mice (1597 pg/ml vs 7261 pg/ml). TNF-alpha mRNA was significantly reduced in bronchoalveolar lavage cells (5-fold) and lung tissue (10-fold). No reduction was seen in neutrophil numbers in the bronchoalveolar lavage fluid, myeloperoxidase activity, or expression of neutrophil chemoattractants CXCL1 and CXCL2, reflecting the specificity of the response. The reduction in TNF-alpha was accompanied by a significant increase in soluble receptors, TNF-SRI (159 pg/ml vs 206 pg/ml) and TNF-SRII (1366 pg/m vs 2695 pg/ml). In conclusion, pulmonary LPS tolerance results in a specific reduction in TNF-alpha expression, while the neutrophilic response is unaffected. This response may be a mechanism to limit tissue damage by reducing TNF-alpha levels, while still maintaining the antimicrobial capacity of the lung.

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.

Chronic LPS inhalation causes emphysema-like changes in mouse lung that are associated with apoptosis

Lipopolysaccharide (LPS) is ubiquitous in the environment. Recent epidemiologic data suggest that occupational exposure to inhaled LPS can contribute to the progression of chronic obstructive pulmonary disease. To address the hypothesis that inhaled LPS can cause emphysema-like changes in mouse pulmonary parenchyma, we exposed C57BL/6 mice to aerosolized LPS daily for 4 weeks. By 3 days after the end of the 4-week exposure, LPS-exposed mice developed enlarged airspaces that persisted in the 4-week recovered mice. These architectural alterations in the lung are associated with enhanced type I, III, and IV procollagen mRNA as well as elevated levels of matrix metalloproteinase (MMP)-9 mRNA, all of which have been previously associated with human emphysema. Interestingly, MMP-9-deficient mice were not protected from the development of LPS-induced emphysema. However, we demonstrate that LPS-induced airspace enlargement was associated with apoptosis within the lung parenchyma, as shown by prominent TUNEL staining and elevated cleaved caspase 3 immunoreactivity. Antineutrophil antiserum-treated mice were partially protected from the lung destruction caused by chronic inhalation of LPS. Taken together, these findings demonstrate that inhaled LPS can cause neutrophil-dependent emphysematous changes in lung architecture that are associated with apoptosis and that these changes may be occurring through mechanisms different than those induced by cigarette smoke.