Exhaled metallic elements and serum pneumoproteins in asymptomatic smokers and patients with COPD or asthma

The association between cadmium exposure and the risk of chronic obstructive pulmonary disease: A systematic review and meta-analysis

According to the World Health Organization, chronic obstructive pulmonary disease (COPD) was one of the top ten causes of death worldwide in 2019. The ratio of forced expiratory volume in the first second to forced vital capacity (FEV1/FVC) provides a useful indicator for the diagnosis of COPD. Existing data have demonstrated that cadmium (Cd) exposure is associated with COPD. However, data concerning the incidence and progression of cadmium-induced COPD is inconsistent. To explore the relationship between cadmium exposure and the risk of COPD in humans, through January 12, 2023, we conducted a thorough search of the PubMed, Cochrane, Web of Science, Embase and Scopus databases for relevant material. In this study, a meta-analysis was conducted to evaluate the association between cadmium and COPD. This meta-analysis indicated that exposure to cadmium (per 1 μg/L increase) was associated with reduced FEV1/FVC (% change = -47.54%, 95% CI: -54.99% to -40.09%). Subgroup analysis showed that the combined effect estimates were significantly higher in the COPD patient group (% change = -54.66%, 95% CI: -83.32% to -26.00%) than in the general population (% change = -52.11%, 95%CI: -60.53% to -43.70%). Therefore, we conclude that cadmium exposure is associated with reduced FEV1/FVC, which suggests a risk for COPD.

Biomarkers in exhaled breath condensate as fingerprints of asthma, chronic obstructive pulmonary disease and asthma-chronic obstructive pulmonary disease overlap: a critical review

Asthma, chronic obstructive pulmonary disease (COPD) and asthma-COPD overlap are the third leading cause of mortality around the world. They share some common features, which can lead to misdiagnosis. To properly manage these conditions, reliable markers for early and accurate diagnosis are needed. Over the past 20 years, many molecules have been investigated in the exhaled breath condensate to better understand inflammation pathways and mechanisms related to these disorders. Recently, more advanced techniques, such as sensitive metabolomic and proteomic profiling, have been used to obtain a more comprehensive understanding. This article reviews the use of targeted and untargeted metabolomic methodology to study asthma, COPD and asthma-COPD overlap.

Use of Vaping as a Smoking Cessation Aid: A Review of Clinical Trials

Purpose

Smoking is a global public health concern, with a significant negative impact on human health and healthcare spending. Vaping, or the use of electronic cigarettes (e-cigarettes), has emerged as a popular alternative to traditional nicotine replacement therapies (NRTs) for smoking cessation. While considered less harmful than combustible cigarettes, the long-term health effects of e-cigarettes (vaping) are unknown. Therefore, this study aimed to identify and provide a comprehensive overview of the performance of vaping in clinical trials.

Patients and Methods

A search was conducted in the ClinicalTrials.gov database on April 14th, 2023, using the search term "smoking cessation, e-cigarettes, NRTs, and vaping". Inclusion and exclusion criteria were defined to identify relevant clinical trials. Randomized controlled trials (RCTs) and non-randomized clinical trials that evaluated vaping as a therapeutic approach to smoking cessation were included.

Results

A total of 87 clinical trials were identified, of which only seven were related to smoking cessation through vaping as a form of treatment. The primary endpoint was the effect of vaping as smoking cessation, and the secondary endpoints were patients' abstinence rate, withdrawal symptoms, and adverse events of e-cigarettes. Most of the trials used e-cigarettes as an intervention, with some trials including a combination of e-cigarettes and other NRTs. The trials lasted from 4 weeks to 12 months. The overall results of the trials indicated that vaping was effective in helping smokers to quit. It was also associated with a lower risk of adverse events than combustible cigarettes.

Conclusion

Vaping appears to be an effective method for smoking cessation, and it is associated with a lower risk of adverse events than combustible cigarettes.

Recommended Reference Intervals for copper and zinc in serum using the US National Health and Nutrition Examination Surveys (NHANES) data

BACKGROUND AND AIMS

In view of the wide variations in reference intervals (RIs) for copper and zinc concentrations in serum, this study was designed to derive appropriate RIs that could be routinely adopted in other laboratories, so allowing better interpretation of results. A secondary aim was to assess the effects of several variables on serum concentrations of copper and zinc.

MATERIALS AND METHODS

Data from over 21,000 individuals were downloaded from four National Health and Nutrition Examination Surveys conducted by the US Centers for Disease Control and Prevention. After controlling for the effects of several variables, age and gender-related RIs were calculated.

RESULTS

A comprehensive list of reference intervals of copper and zinc in serum is provided. Serum copper concentrations were affected by age, gender, ethnicity, pregnancy, use of oral contraceptive pill, health status and smoking (in males). Serum zinc concentrations were affected by gender, age, fasting, ethnicity, serum albumin concentration, health status (in males), time of venipuncture and pregnancy.

CONCLUSION

Reliable RIs for copper and zinc in serum were derived. As analytical accuracy and precision were assured and optimal sample collection protocols were followed, these RIs can be transferred for routine use in other clinical biochemistry laboratories with good analytical performance in external quality assurance schemes.

Facets of ICP-MS and their potential in the medical sciences-Part 1: fundamentals, stand-alone and hyphenated techniques

Since its inception in the early 80s, inductively coupled plasma–mass spectrometry has developed to the method of choice for the analysis of elements in complex biological systems. High sensitivity paired with isotopic selectivity and a vast dynamic range endorsed ICP-MS for the inquiry of metals in the context of biomedical questions. In a stand-alone configuration, it has optimal qualities for the biomonitoring of major, trace and toxicologically relevant elements and may further be employed for the characterisation of disrupted metabolic pathways in the context of diverse pathologies. The on-line coupling to laser ablation (LA) and chromatography expanded the scope and application range of ICP-MS and set benchmarks for accurate and quantitative speciation analysis and element bioimaging. Furthermore, isotopic analysis provided new avenues to reveal an altered metabolism, for the application of tracers and for calibration approaches. In the last two decades, the scope of ICP-MS was further expanded and inspired by the introduction of new instrumentation and methodologies including novel and improved hardware as well as immunochemical methods. These additions caused a paradigm shift for the biomedical application of ICP-MS and its impact in the medical sciences and enabled the analysis of individual cells, their microenvironment, nanomaterials considered for medical applications, analysis of biomolecules and the design of novel bioassays. These new facets are gradually recognised in the medical communities and several clinical trials are underway. Altogether, ICP-MS emerged as an extremely versatile technique with a vast potential to provide novel insights and complementary perspectives and to push the limits in the medical disciplines. This review will introduce the different facets of ICP-MS and will be divided into two parts. The first part will cover instrumental basics, technological advances, and fundamental considerations as well as traditional and current applications of ICP-MS and its hyphenated techniques in the context of biomonitoring, bioimaging and elemental speciation. The second part will build on this fundament and describe more recent directions with an emphasis on nanomedicine, immunochemistry, mass cytometry and novel bioassays.

Association between environmental toxic metals, arsenic and polycyclic aromatic hydrocarbons and chronic obstructive pulmonary disease in the US adult population

Associations between environmental metals and chemicals and adverse human health effects have emerged recently, but the links among environmental metals and respiratory diseases are less studied. The aim of this study was to assess 14 urinary metals (cadmium, barium, cobalt, molybdenum, mercury, cesium, manganese, antimony, lead, tin, strontium, tungsten, thallium, and uranium), seven species of arsenic (arsenous acid, arsenic acid, arsenobetaine, arsenocholine, dimethylarsinic acid, monomethylarsonic acid, and total arsenic) and seven polycyclic aromatic hydrocarbon (PAH) (1-hydroxynaphthalene, 2-hydroxynaphthalene, 3-hydroxyfluorene, 2-hydroxyfluorene, 1-hydroxyphenanthrene, 1-hydroxypyrene, 2 & 3-hydroxyphenanthrene) compounds' concentrations in urine and the correlation with chronic obstructive pulmonary disease (COPD) in the adult US population. A cross-sectional analysis using the 2013-2014 and 2015-2016 National Health and Nutrition Examination Survey (NHANES) dataset was conducted. Self-questionnaires related to COPD criteria were used to identify the COPD cases. The correlation between urinary metals and PAH compounds and COPD was calculated. The total study population analyzed included 2885 adults aged 20 years and older. Seven types of urinary PAHs including 1-hydroxynaphthalene [odds ratio (OR): 1.832, 95% confidence interval (CI): 1.210, 2.775], 2-hydroxynaphthalene [OR: 3.361, 95% CI: 1.519, 7.440], 3-hydroxyfluorene [OR: 2.641, 95% CI: 1.381, 5.053], 2-hydroxyfluorene [OR: 3.628, 95% CI: 1.754, 7.506], 1-hydroxyphenanthrene [OR: 2.864, 95% CI: 1.307, 6.277], 1-hydroxypyrene [OR: 4.949, 95% CI: 2.540, 9.643] and 2 & 3-hydroxyphenanthrene [OR: 3.487, 95% CI: 1.382, 8.795] were positively associated with COPD. Urinary cadmium [OR: 12.382, 95% CI: 4.459, 34.383] and tin [OR: 1.743, 95% CI: 1.189, 2.555] showed positive associations with increased odds of COPD. The other types of urinary metals were not associated with COPD. The study observed that urinary PAHs, cadmium, and tin are significantly associated with COPD.

Cigarette Smoke Particle-Induced Lung Injury and Iron Homeostasis

It is proposed that the mechanistic basis for non-neoplastic lung injury with cigarette smoking is a disruption of iron homeostasis in cells after exposure to cigarette smoke particle (CSP). Following the complexation and sequestration of intracellular iron by CSP, the host response (eg, inflammation, mucus production, and fibrosis) attempts to reverse a functional metal deficiency. Clinical manifestations of this response can present as respiratory bronchiolitis, desquamative interstitial pneumonitis, pulmonary Langerhans’ cell histiocytosis, asthma, pulmonary hypertension, chronic bronchitis, and pulmonary fibrosis. If the response is unsuccessful, the functional deficiency of iron progresses to irreversible cell death evident in emphysema and bronchiectasis. The subsequent clinical and pathological presentation is a continuum of lung injuries, which overlap and coexist with one another. Designating these non-neoplastic lung injuries after smoking as distinct disease processes fails to recognize shared relationships to each other and ultimately to CSP, as well as the common mechanistic pathway (ie, disruption of iron homeostasis).

Towards a toxic-free environment: perspectives for chemical risk assessment approaches

Regulatory frameworks to control chemical exposure in general living and occupational environments have changed exposure scenarios towards a widely spread contamination at relatively low doses in developed countries. In such evolving context, some critical aspects should be considered to update risk assessment and management strategies. Risk assessment in low-dose chemical exposure scenarios should take advantage of: toxicological investigations on emerging substances of interest, like those recognised as endocrine disruptors or increasingly employed nanoscale materials; human biological monitoring studies aimed to identify innovative biomarkers for known chemical exposure; “omic” technologies useful to identify hazards of chemicals and their modes of action. For updated risk assessment models, suitable toxicological studies, analyses of dose-responses at low-concentrations, environmental and biological monitoring of exposure, together with exposome studies, and the proper definition of susceptible populations may all provide helpful contributions. These may guide defining preventive measures to control the exposure and develop safe and sustainable chemicals by design. Occupational medicine can offer know-how and instruments to understand and manage such evolution towards a toxic-free environment to protect the safety and health of the workforce and, in turn, that of the general population.

OUP accepted manuscript

Background

COVID-19 is a highly contagious respiratory disease that can be transmitted through human exhaled breath. It has caused immense loss and has challenged the healthcare sector. It has affected the economy of countries and thereby affected numerous sectors. Analysis of human breath samples is an attractive strategy for rapid diagnosis of COVID-19 by monitoring breath biomarkers.

Content

Breath collection is a noninvasive process. Various technologies are employed for detection of breath biomarkers like mass spectrometry, biosensors, artificial learning, and machine learning. These tools have low turnaround time, robustness, and provide onsite results. Also, MS-based approaches are promising tools with high speed, specificity, sensitivity, reproducibility, and broader coverage, as well as its coupling with various chromatographic separation techniques providing better clinical and biochemical understanding of COVID-19 using breath samples.

Summary

Herein, we have tried to review the MS-based approaches as well as other techniques used for the analysis of breath samples for COVID-19 diagnosis. We have also highlighted the different breath analyzers being developed for COVID-19 detection.

Association of serum surfactant protein D and SFTPD gene variants with asthma in Danish children, adolescents, and young adults

BACKGROUND

Surfactant Protein D (SP-D) is a pattern recognition molecule belonging to the family of collectins expressed in multiple human organ systems, including the lungs. Previous studies have shown that SP-D levels in bronchoalveolar lavage samples decrease and serum levels increase in patients suffering from asthma, possibly due to a combination of induced SP-D synthesis and decreased air-blood barrier integrity. The aims of this study were to investigate whether serum levels of SP-D and common variants in the SP-D gene were associated with asthma in adolescents and young adults.

METHODS

Prospective observational study including 449 adolescents and young adults (age 11-27 years) previously diagnosed with asthma during a 2-year period from 2003 to 2005 (0-16 years). At follow-up from 2016 to 2017, 314 healthy controls with no history of asthma were recruited. Serum SP-D was analyzed on samples obtained at baseline as well as samples obtained at follow-up. SP-D genotyping was performed for rs721917, rs2243639, and rs3088308.

RESULTS

No differences were found in mean levels of sSP-D and SFTPD genotype among subjects with current asthma, no current asthma, and controls. Serum SP-D and SFTPD genotype were not associated with any clinical parameters of asthma. Furthermore, baseline sSP-D was not associated with asthma at follow-up.

CONCLUSION

Serum surfactant protein D and common SP-D gene variants were not associated with asthma in Danish adolescents and young adults with mild to moderate asthma. Serum surfactant protein D did not demonstrate any value as a clinical biomarker of asthma.

Mineral Micronutrients in Asthma

Asthma represents one of the most common medical issues in the modern world. It is a chronic inflammatory disease characterized by persistent inflammation of the airways and disturbances in redox status, leading to hyperresponsiveness of bronchi and airway obstruction. Apart from classical risk factors such as air pollution, family history, allergies, or obesity, disturbances of the levels of micronutrients lead to impairments in the defense mechanisms of the affected organism against oxidative stress and proinflammatory stimuli. In the present review, the impact of micronutrients on the prevalence, severity, and possible risk factors of asthma is discussed. Although the influence of classical micronutrients such as selenium, copper, or zinc are well known, the effects of those such as iodine or manganese are only rarely mentioned. As a consequence, the aim of this paper is to demonstrate how disturbances in the levels of micronutrients and their supplementation might affect the course of asthma.

Oxidative Stress and Inflammatory Mediators in Exhaled Breath Condensate of Patients with Pulmonary Tuberculosis. A Pilot Study with a Biomarker Perspective

Tuberculosis (TB) is one of the highest infectious burdens worldwide. An excess of inflammation and inadequate antioxidant defense mechanisms are believed to lead to chronic inflammation and lung damage in tuberculosis (TB). However, circulating metabolites do not always replicate lung-associated biomarkers that define the pathobiology of the disease. The objective of this study was to determine the utility of exhaled breath condensate (EBC), a non-invasive and straightforward sample, to evaluate alveolar space-derived metabolites of redox state and inflammation. We assessed the levels of exhaled oxidant/antioxidant parameters (8-isoprostane, MDA, GSH), inflammatory markers, such as nucleosomes, cytokines (IL-2, IL-4, IL-6 and IL-8, IL-10, GM-CSF, TNF-α, and IFN-γ) and lipid mediators (PGE2, LTB4, RvD1, and Mar1), in patients with recently diagnosed pulmonary TB and healthy controls’ EBC and serum. The TB patients showed 36% lower GSH levels, and 2-, 1.4-, 1.1-, and 50-fold higher levels of 8-isoprostanes, nucleosomes, IL-6, and LTB4, respectively, in EBC. There was no correlation between EBC and serum, highlighting the importance of measuring local biomarkers. Quantitation of local inflammatory molecules and redox states in EBC would help find biomarkers useful for pharmacological and follow-up studies in pulmonary tuberculosis.

Particle and metal exposure in Parisian subway: Relationship between exposure biomarkers in air, exhaled breath condensate, and urine

Subway particulate toxicity results from in vitro and in vivo studies diverge and call for applied human research on outcomes from chronic exposures and potential exposure biomarkers. We aimed to (1) quantify airborne particulate matter (PM) concentrations (mass and number) and metal concentrations in exhaled breath condensate (EBC), urine, and PM; (2) investigate their associations (EBC vs. PM vs. urine); and (3) assess the relevance of EBC in biomonitoring. Nine subway workers in three jobs: station agents, locomotive operators and security guards were monitored during their 6-h shifts over two consecutive weeks. Six-hour weighed average mass concentrations expressed as PM10, PM2.5 and their metal concentrations were determined. Urine and EBC samples were collected pre- and post-shift. Ultrafine particle (UFP) number concentrations were quantified in PM and EBC samples. Metal concentrations in urine and EBC were standardized by creatinine and EBC volume, respectively, and log-transformed. Associations were investigated using Pearson correlation and linear mixed regression models, with participant's ID as random effect. PM concentrations were below occupational exposure limits (OEL) and varied significantly between jobs. Locomotive operators had the highest exposure (189 and 137 μg/m³ for PM10 and PM2.5, respectively), while station agents had the highest UFP exposure (1.97 × 10⁴ particles/cm³). Five metals (Al, Fe, Zn, Cu, and Mn) in PM2.5 and three (Al, Fe, and Zn) in PM10 were above the limit of quantification (LOQ). Fe, Cu, Al and Zn were the most abundant by mass fraction in PM. In EBC, the metal concentrations in decreasing order were: Zn > Cu > Ni > Ba > Mn. Security guards had the highest EBC metal concentrations, and in particular Zn and Cu. Urinary metal concentrations in decreasing order were: Si > Zn > Mo > Ti > Cu > Ba ≈ Ni > Co. All urinary metal concentrations from the subway workers were similar to concentrations found in the general population. A statistically significant relationship was found for ultrafine particle number concentrations in PM and in EBC. Zn and Cu concentrations in post-shift EBC were associated with Zn and Cu concentrations in PM10 and with post-shift urinary Zn and Cu concentrations. Therefore, EBC appears a relevant matrix for assessing exposure to UFP in human biomonitoring when inhalation is a primary route of exposure. We found different temporal variation patterns between particle and metal exposures in three matrices (PM, urine, EBC) quantified daily over two full weeks in subway workers. These patterns might be related to metal oxidation, particulates' solubility and size as well as their lung absorption capabilities, which need to be further explored in toxicological research. Further research should also focus on understanding possible influences of low chronic exposures to subway particulates on health in larger cohorts.

Mass Spectrometry-Based Human Breath Analysis: Towards COVID-19 Diagnosis and Research

COVID-19 is a highly contagious respiratory disease that can be infected through human exhaled breath. Human breath analysis is an attractive strategy for rapid diagnosis of COVID-19 in a non-invasive way by monitoring breath biomarkers. Mass spectrometry (MS)-based approaches offer a promising analytical platform for human breath analysis due to their high speed, specificity, sensitivity, reproducibility, and broad coverage, as well as its versatile coupling methods with different chromatographic separation, and thus can lead to a better understanding of the clinical and biochemical processes of COVID-19. Herein, we try to review the developments and applications of MS-based approaches for multidimensional analysis of COVID-19 breath samples, including metabolites, proteins, microorganisms, and elements. New features of breath sampling and analysis are highlighted. Prospects and challenges on MS-based breath analysis related to COVID-19 diagnosis and study are discussed.

CC16 Binding to α4β1 Integrin Protects against Mycoplasma pneumoniae Infection

Rationale CC16 (club cell secretory protein) is a pneumoprotein produced predominantly by pulmonary club cells. Circulating CC16 is associated with protection from the inception and progression of the two most common obstructive lung diseases (asthma and chronic obstructive pulmonary disease). Objectives Although exact mechanisms remain elusive, studies consistently suggest a causal role of CC16 in mediating antiinflammatory and antioxidant functions in the lung. We sought to determine any novel receptor systems that could participate in CC16's role in obstructive lung diseases. Methods Protein alignment of CC16 across species led to the discovery of a highly conserved sequence of amino acids, leucine-valine-aspartic acid (LVD), a known integrin-binding motif. Recombinant CC16 was generated with and without the putative integrin-binding site. A Mycoplasma pneumoniae mouse model and a fluorescent cellular adhesion assay were used to determine the impact of the LVD site regarding CC16 function during live infection and on cellular adhesion during inflammatory conditions. Measurements and Main Results CC16 bound to integrin α₄β₁), also known as the adhesion molecule VLA-4 (very late antigen 4), dependent on the presence of the LVD integrin-binding motif. During infection, recombinant CC16 rescued lung function parameters both when administered to the lung and intravenously but only when the LVD integrin-binding site was intact; likewise, neutrophil recruitment during infection and leukocyte adhesion were both impacted by the loss of the LVD site. Conclusions We discovered a novel receptor for CC16, VLA-4, which has important mechanistic implications for the role of CC16 in circulation as well as in the lung compartment.

The levels of trace elements in sputum as biomarkers for idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a rare lung disease that quickly leads to death. This paper addressed the issue of whether the levels of trace elements in sputum samples are suitable biomarkers for IPF disease. The sputum Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn concentrations were measured by sector field inductively coupled plasma mass spectrometry in populations sampled in Sardinia Island (Italy) including 31 patients with IPF, 31 patients with other lung-related diseases and 30 age- and gender-matched healthy controls. Risk factors in the disease as gender, age, severity and duration of the disease were assessed. Results showed that IPF patients had significantly increased sputum levels of Cd, Cr, Cu and Pb respect to controls. In males, but not in females, sputum levels of Cd, Cr and Cu were significantly higher in IPF cases respect to controls. In addition, Cr and Pb were increased in male patients with IPF compared to male patients with other lung diseases. Regarding Zn, it was found higher with the more serious stage of disease. Moreover, the ratios Cu/Zn, Fe/Mn and Cu/Mn were significantly increased in IPF patients and in non-IPF patients than in control subjects. These data showed clear increases in the concentration of some trace elements in sputum from patients with IPF and patients with other lung-related diseases that may contribute to the injury. The non-invasiveness of the sputum analysis is beneficial for its use as biomarker of trace element status in diseased patients for both the researcher and the clinic.

Nutritional immunity: the impact of metals on lung immune cells and the airway microbiome during chronic respiratory disease

Nutritional immunity is the sequestration of bioavailable trace metals such as iron, zinc and copper by the host to limit pathogenicity by invading microorganisms. As one of the most conserved activities of the innate immune system, limiting the availability of free trace metals by cells of the immune system serves not only to conceal these vital nutrients from invading bacteria but also operates to tightly regulate host immune cell responses and function. In the setting of chronic lung disease, the regulation of trace metals by the host is often disrupted, leading to the altered availability of these nutrients to commensal and invading opportunistic pathogenic microbes. Similarly, alterations in the uptake, secretion, turnover and redox activity of these vitally important metals has significant repercussions for immune cell function including the response to and resolution of infection. This review will discuss the intricate role of nutritional immunity in host immune cells of the lung and how changes in this fundamental process as a result of chronic lung disease may alter the airway microbiome, disease progression and the response to infection.

Metallomics Analysis for Assessment of Toxic Metal Burdens in Infants/Children and Their Mothers: Early Assessment and Intervention Are Essential

Accumulation of toxic metals in infants/children is of serious concern worldwide, from the viewpoint of their harmful effects on the normal growth and development. This metallomics study investigates the extent of toxic metal burdens in infants/children and the relationship to those in their mothers for 77 child/mother pair subjects. For mercury, its geometric mean concentration in infants/children was of similar level to that in their mothers, and a high-significant close correlation was observed between infants/children and their mothers (β = 0.758, r = 0.539, p < 0.0001). A significant but less intimate mother/child relationship was observed for arsenic (β = 0.301, r = 0.433), lead (β = 0.444, r = 0.471) and aluminum (β = 0.379, r = 0.451). Remarkably, the burden levels of lead, cadmium and aluminum in infants/children were approximately three times higher than those in their mothers (p < 0.0001), and the burden levels in some individuals were several tens of times higher than in the mothers. In contrast, some essential metal levels such as zinc, magnesium and calcium in infants/children were significantly lower than those in their mothers, and 29 individuals (37.7%) in the child subjects were estimated to be zinc-deficient. In addition, significant inverse correlations were observed between zinc and lead (r = −0.267, p = 0.019), and magnesium and arsenic (r = −0.514, p < 0.0001). These findings suggest that these toxic metal burdens and essential metal deficiencies in infants/children are of serious concern for their neurodevelopment, indicating that the early assessment and intervention are crucial. It is expected that larger epidemiological and intervention studies will provide a reasonable and essential pathway for intervention of neurodevelopment disorders.

Acrolein in cigarette smoke attenuates the innate immune responses mediated by surfactant protein D

BACKGROUND

Surfactant proteins (SP) A and D belong to collectin family proteins, which play important roles in innate immune response in the lung. We previously demonstrated that cigarette smoke (CS) increases the acrolein modification of SP-A, thereby impairing the innate immune abilities of this protein. In this study, we focused on the effects of CS and its component, acrolein, on the innate immunity role of another collectin, SP-D.

METHODS

To determine whether aldehyde directly affects SP-D, we examined the lungs of mice exposed to CS for 1 week and detected aldehyde-modified SP-D using an aldehyde reactive probe. The structural changes in CS extract (CSE) or acrolein-exposed recombinant human (h)SP-D were determined by western blot, liquid chromatography-electrospray ionization tandem mass spectrometry, and blue native-polyacrylamide gel electrophoresis analyses. Innate immune functions of SP-D were determined by bacteria growth and macrophage phagocytosis.

RESULTS

Aldehyde-modified SP-D as well as SP-A was detected in the lungs of mice exposed to CS for 1 week. Exposure of hSP-D to CSE or acrolein induced an increased higher-molecular -weight of hSP-D and acrolein induced modification of five lysine residues in hSP-D. These modifications led to disruption of the multimer structure of SP-D and attenuated its ability to inhibit bacterial growth and activate macrophage phagocytosis.

CONCLUSION

CS induced acrolein modification in SP-D, which in turn induced structural and functional defects in SP-D.

GENERAL SIGNIFICANCE

These results suggest that CS-induced structural and functional defects in SP-D contribute to the dysfunction of innate immune responses in the lung following CS exposure.

Control of the Lung Residence Time of Highly Permeable Molecules after Nebulization: Example of the Fluoroquinolones

Pulmonary drug delivery is a promising strategy to treat lung infectious disease as it allows for a high local drug concentration and low systemic side effects. This is particularly true for low-permeability drugs, such as tobramycin or colistin, that penetrate the lung at a low rate after systemic administration and greatly benefit from lung administration in terms of the local drug concentration. However, for relatively high-permeable drugs, such as fluoroquinolones (FQs), the rate of absorption is so high that the pulmonary administration has no therapeutic advantage compared to systemic or oral administration. Formulation strategies have thus been developed to decrease the absorption rate and increase FQs’ residence time in the lung after inhalation. In the present review, some of these strategies, which generally consist of either decreasing the lung epithelium permeability or decreasing the release rate of FQs into the epithelial lining fluid after lung deposition, are presented in regards to their clinical aspects.

Serum Clara cell secretory protein (CC-16) in non-smoking patients with obstructive sleep apnea

OBJECTIVE

This study aimed to determine the association between the severity of obstructive sleep apnea (OSA) and serum Clara cell protein (CC16) levels in non-smoking patients with OSA.

METHODS

This prospective study included non-smoking patients who presented with sleep-related disturbances and underwent polysomnography (PSG). The serum CC16 level was measured and its relationship to PSG parameters was investigated.

RESULTS

The study included 128 patients (83 men) with a mean age of 48.4 ± 11.9. OSA was detected in 66 men (70%) and 29 women (30%) (p = 0.051). The severity of OSA was mild in 32 (25%), moderate in 28 (22%), and severe in 35 (27%) of the patients. There was no significant difference in CC16 levels between the OSA group (1746 ± 1006) and the OSA negative group (1721 ± 1201, p = 0.91) levels. There was no significant difference between the CC16 levels of the each four groups. Mean serum CC16 levels were significantly lower in OSA negative men than OSA positive men (777 vs 1462, p = 0.005). No significant difference was observed in CC16 values according to OSA severity in women.

CONCLUSION

The serum CC16 level does not differ between non-smoking OSA patients and OSA negative patients.

Exhaled breath analysis in the diagnosis of head and neck cancer

Head and neck cancer (HNC) comprises a heterogeneous group of upper aerodigestive tract malignant neoplasms, the most frequent of which is squamous cell carcinoma. HNC forms the eighth most common cancer type and the incidence is increasing. However, survival has improved only moderately during the past decades. Currently, early diagnosis remains the mainstay for improving treatment outcomes in this patient population. Unfortunately, screening methods to allow early detection of HNC are not yet established. Therefore, many cases are still diagnosed at advanced stage, compromising outcomes. Exhaled breath analysis (EBA) is a diagnostic tool that has been recently introduced for many cancers. Breath analysis is non-invasive, cost-effective, time-saving, and can potentially be applied for cancer screening. Here, we provide a summary of the accumulated evidence on the feasibility of EBA in the diagnosis of HNC.

Copper-Heparin Inhalation Therapy To Repair Emphysema: A Scientific Rationale

Current pharmacotherapy of chronic obstructive pulmonary disease (COPD) aims at reducing respiratory symptoms and exacerbation frequency. Effective therapies to reduce disease progression, however, are still lacking. Furthermore, COPD medications showed less favorable effects in emphysema than in other COPD phenotypes. Elastin fibers are reduced and disrupted, whereas collagen levels are increased in emphysematous lungs. Protease/antiprotease imbalance has historically been regarded as the sole cause of emphysema. However, it is nowadays appreciated that emphysema may also be provoked by perturbations in the sequential repair steps following elastolysis. Essentiality of fibulin-5 and lysyl oxidase-like 1 in the elastin restoration process is discussed, and it is argued that copper deficiency is a plausible reason for failing elastin repair in emphysema patients. Since copper-dependent lysyl oxidases crosslink elastin as well as collagen fibers, copper supplementation stimulates accumulation of both proteins in the extracellular matrix. Restoration of abnormal elastin fibers in emphysematous lungs is favorable, whereas stimulating pulmonary fibrosis formation by further increasing collagen concentrations and organization is detrimental. Heparin inhibits collagen crosslinking while stimulating elastin repair and might therefore be the ideal companion of copper for emphysema patients. Efficacy and safety considerations may lead to a preference of pulmonary administration of copper-heparin over systemic administration.

Quantification of Trace Elements in Different Dokha and Shisha Tobacco Products using EDXRF

The present study aims to quantify trace metals in different dokha (medwakh) and shisha tobacco products available in local markets. Recent research has shown that these products have higher amounts of nicotine and tar compared to various other tobacco products. No specific data are available on the concentration of trace elements in dokha (medwakh) and shisha tobacco products in the Middle East and North Africa (MENA) region. Harmful health effects due to the toxicity of these elements in tobacco and its smoke have not been adequately emphasized. Concentrations of trace elements were extensively studied using HORIBA XGT-7200 EDXRF fluorescence absorption spectroscopy. The mean concentrations of aluminum, calcium, chromium, copper, iron, magnesium, manganese, nickel, potassium, strontium and zinc in 13 dokha products in μg/g were 406.92 ± 41.72, 14703.27 ± 271.73, 11.73 ± 2.12, 25.58 ± 2.63, 753.85 ± 14.87, 5306.54 ± 134.94, 82.31 ± 4.55, 25.58 ± 2.50, 2212.12 ± 39.04, 816.92 ± 15.26 and 35.96 ± 2.63, respectively; and those in the three shisha products in μg/g were 244.83 ± 25.11, 8235.77 ± 144.51, 3.40 ± 0.38, 22.77 ± 4.50, 569.13 ± 10.22, 2096.20 ± 130.69, 72.13 ± 7.13, 27.67 ± 5.31, 4467.50 ± 168.06, 320.20 ± 6.03 and 36.40 ± 3.57, respectively. In our study, the quantified trace metal concentrations in dokha and shisha tobacco using the EDXRF method were ten times higher than the LODs. The percentage of RSD was <10%, validating the precision of the method. Tobacco smoking is a major source of consumption of toxic elements, not only in the smoker but also in non-smokers through passive smoking. In dokha (medwakh) and shisha tobacco products, compared with cigarettes, Ni levels were significantly higher, Cr, Cu and Zn levels were higher, and Fe levels were similar, while Al and Mn levels were lower. The dokha and shisha tobacco products have no filters; many toxic metals can quickly enter the lungs and cause different pulmonary diseases and oral infections. Tobacco smoking causes lung and oral cancers, chronic obstructive pulmonary disease and cardiovascular diseases.

Pneumoproteins in Offshore Drill Floor Workers

The aim was to assess pneumoproteins and a certain biomarker of systemic inflammation in drill floor workers exposed to airborne contaminants generated during drilling offshore, taking into consideration serum biomarkers of smoking, such as nicotine (S-Nico) and cotinine. Blood samples of club cell protein 16 (CC-16), surfactant protein D (SP-D) and C-reactive protein (CRP) were collected before and after a 14-day work period from 65 drill floor workers and 65 referents. Air samples of oil mist, drilling mud components and elemental carbon were collected in person. The drill floor workers were exposed to a median air concentration of 0.18 mg/m³ of oil mist and 0.14 mg/m³ of airborne mud particles. There were no differences in the concentrations of CC-16 and SP-D across the 14-day work period and no difference between drill floor workers and referents at baseline after adjusting for differences in sampling time and smoking. CRP decreased across the work period. There was a strong association between the CC-16 concentrations and the time of sampling. Current smokers with S-Nico > detection limit (DL) had a statistically significantly lower CC-16 concentration, while smokers with S-Nico < DL had CC-16 concentrations similar to that of the non-smokers. Fourteen days of work offshore had no effect on serum pneumoprotein and CRP concentrations. However, the time of blood sampling was observed to have a strong effect on the measured concentrations of CC-16. The effect of current smoking on the CC-16 concentrations appears to be dependent on the S-Nico concentrations.

The modification of indoor PM2.5 exposure to chronic obstructive pulmonary disease in Chinese elderly people: A meet-in-metabolite analysis

BACKGROUND

Exposure to airborne fine particulate matter (PM_2.5) has been associated with a variety of adverse health outcomes including chronic obstructive pulmonary disease (COPD). However, the linkages between PM_2.5 exposure, PM_2.5-related biomarkers, COPD-related biomarkers and COPD remain poorly elucidated.

OBJECTIVES

To investigate the linkages between PM_2.5 exposure and COPD outcome by using the meet-in-middle strategy based on urinary metabolic biomarkers.

METHODS

A cross-sectional study was designed to illustrate the mentioned quadripartite linkages. Indoor PM_2.5 and its element components were assessed in 41 Chinese elderly participants including COPD patients and their healthy spouses. Metabolic biomarkers involved in PM_2.5 exposure and COPD were identified by using urinary metabolomics. The associations between PM_2.5- and COPD-related biomarkers were investigated by statistics and metabolic pathway analysis.

RESULTS

Seven metabolites were screened and identified with significant correlations to PM_2.5 exposure, which were majorly involved in purine and amino acid metabolism as well as glycolysis. Ten COPD-related metabolic biomarkers were identified, which suggested that amino acid metabolism, lipid and fatty acid metabolism, and glucose metabolism were disturbed in the patients. Also, PM_2.5 and its many elemental components were significantly associated with COPD-related biomarkers. We observed that the two kinds of biomarkers (PM_2.5- and COPD-related) integrated in a locally connected network and the alterations of these metabolic biomarkers can biologically link PM_2.5 exposure to COPD outcome.

CONCLUSIONS

Our study indicated the modification of PM_2.5 to COPD via both modes of action of lowering participants' antioxidation capacity and decreasing their lung energy generation; this information would be valuable for the prevention strategy of COPD.

Iron concentration in exhaled breath condensate decreases in ever-smokers and COPD patients

Investigation employing bronchoalveolar lavage supports both increased and decreased iron concentrations in the epithelial lining fluid (ELF) of smokers. Exhaled breath condensate (EBC) is an alternative approach to sampling the ELF. We evaluated for an association between iron homeostasis and both smoking and a diagnosis of chronic obstructive pulmonary disease (COPD) by measuring metal concentrations in EBC samples from non-smoker controls, smoker controls, and individuals diagnosed with COPD. The total number of EBC specimens was 194. EBC iron and zinc concentrations (mean ± standard error) in the total study population were 0.610 ± 0.025 and 40.73 ± 1.79 ppb respectively. In linear regressions, total cigarette smoking in pack years showed a significant (negative) relationship with EBC iron concentration but not with EBC zinc concentration. Iron concentrations in EBC from GOLD stage II, III, and IV patients were all significantly decreased relative to those from non-smoker and smoker controls. In contrast to iron, zinc concentrations in EBC were not significantly different than those from non-smoker and smoker controls. It is concluded that smoking decreases EBC iron concentrations and patients diagnosed with COPD have significantly lower EBC iron concentrations. These results likely reflect an increased burden of cigarette smoke particles in the lower respiratory tract of ever-smokers and patients with COPD and the capacity of components in this particle to complex iron.

Biomarkers of respiratory allergy in laboratory animal care workers: an observational study

OBJECTIVES

Laboratory animal allergy is a highly prevalent occupational disease among exposed workers. The aim of the study was to validate the biomarkers of airway inflammation in laboratory animal (LA) care workers.

METHODS

All of the participants in this observational study (63 LA care workers and 64 controls) were administered a clinical questionnaire, underwent spirometry and a skin prick or radioallergosorbent test for common and occupational aeroallergens, and the fraction of exhaled nitric oxide (FeNO₅₀), exhaled breath condensate hydrogen peroxide (EBC H₂O₂) and serum pneumoprotein levels were measured. Multivariate analysis (ANCOVA) was used to assess the interactions of the variables.

RESULTS

FeNO₅₀ levels correlated with exposure (p = 0.002), sensitisation (p = 0.000) and age (p = 0.001), but there was no interaction between exposure and sensitisation when age was considered in the model (p = 0.146). EBC-H₂O₂ levels were higher in the sensitised workers than in the sensitised controls [0.14 (0.08-0.29) µM vs 0.07 (0.05-0.12) µM; p < 0.05]. Serum surfactant protein A (SP-A) levels were unaffected by exposure, sensitisation or age, although higher levels were observed in symptomatic workers; however, SP-D levels were influenced by exposure (p = 0.024) and age (p = 0.022), and club cell 16 levels were influenced by sensitisation (p = 0.027) and age (p = 0.019).

CONCLUSIONS

The presence of the clinical symptoms associated with LA exposure and high FeNO levels should prompt further medical assessments in LA workers. Although EBC-H₂O₂ levels do not seem to reflect eosinophilic inflammation, serum SP-A levels could be used to monitor progression from rhinitis to asthma.

Surfactant Protein D in Respiratory and Non-Respiratory Diseases

Surfactant protein D (SP-D) is a multimeric collectin that is involved in innate immune defense and expressed in pulmonary, as well as non-pulmonary, epithelia. SP-D exerts antimicrobial effects and dampens inflammation through direct microbial interactions and modulation of host cell responses via a series of cellular receptors. However, low protein concentrations, genetic variation, biochemical modification, and proteolytic breakdown can induce decomposition of multimeric SP-D into low-molecular weight forms, which may induce pro-inflammatory SP-D signaling. Multimeric SP-D can decompose into trimeric SP-D, and this process, and total SP-D levels, are partly determined by variation within the SP-D gene, SFTPD. SP-D has been implicated in the development of respiratory diseases including respiratory distress syndrome, bronchopulmonary dysplasia, allergic asthma, and chronic obstructive pulmonary disease. Disease-induced breakdown or modifications of SP-D facilitate its systemic leakage from the lung, and circulatory SP-D is a promising biomarker for lung injury. Moreover, studies in preclinical animal models have demonstrated that local pulmonary treatment with recombinant SP-D is beneficial in these diseases. In recent years, SP-D has been shown to exert antimicrobial and anti-inflammatory effects in various non-pulmonary organs and to have effects on lipid metabolism and pro-inflammatory effects in vessel walls, which enhance the risk of atherosclerosis. A common SFTPD polymorphism is associated with atherosclerosis and diabetes, and SP-D has been associated with metabolic disorders because of its effects in the endothelium and adipocytes and its obesity-dampening properties. This review summarizes and discusses the reported genetic associations of SP-D with disease and the clinical utility of circulating SP-D for respiratory disease prognosis. Moreover, basic research on the mechanistic links between SP-D and respiratory, cardiovascular, and metabolic diseases is summarized. Perspectives on the development of SP-D therapy are addressed.

Transition and post-transition metals in exhaled breath condensate

Water vapor in expired air, as well as dispersed non-volatile components, condense onto a cooler surface after exiting the respiratory tract. This exhaled breath condensate (EBC) provides a dilute sampling of the epithelial lining fluid. Accordingly, the collection of EBC imparts a capacity to provide biomarkers of injury preceding clinical disease. Concentrations of transition and post-transition metals in EBC are included among these endpoints. Iron and zinc are the metals with the highest concentration and are measurable in all EBC samples from healthy subjects; other metals are most frequently either at or below the level of detection in this group. Gender, age, and smoking can impact EBC metal concentrations in healthy subjects. EBC metal concentrations among patients diagnosed with particular lung diseases (e.g. asthma, chronic obstructive disease, and interstitial lung disease) have been of research interest but no definite pattern of involvement has been delineated. Studies of occupationally exposed workers confirm significant exposure to specific metals, but such EBC metal measurements frequently provide evidence redundant with environmental sampling. Measurements of metal concentrations in EBC remain a research tool into metal homeostasis in the respiratory tract and participation of metals in disease pathogenesis. The quantification of metal concentrations in EBC is currently not reliable for clinical use in either supporting or determining any diagnosis. Issues that must be addressed prior to the use of EBC metal measurements include the establishment of both standardized collection and measurement techniques.

Simvastatin Therapy and Bronchoalveolar Lavage Fluid Biomarkers in Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) is a progressive disease underlain by airway inflammation. Despite trials with new generations of anti-inflammatory drugs to alleviate the disease burden, the effective curative treatment remains elusive. In this context, the aim of this study was to assess the influence of simvastatin, a leading member of the family of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, known to display anti-inflammatory and immunomodulatory activity, on symptoms and lung function, as well as the proportion of inflammatory cells, cytokines, proteolytic enzymes, and surfactant protein D (SP-D) content in bronchoalveolar lavage fluid (BALF) in COPD patients. There were 50 patients with moderate-to-severe airway obstructions included into the study, subdivided into simvastatin-treated (Zocor - MSD; 40 mg daily) and control simvastatin-untreated groups, other treatment being equal. Pulmonary functions tests and bronchofiberoscopy with BALF procedure were performed before and after 3-month-long treatment in both groups. The major finding was that simvastatin treatment caused a distinct increase in the airway content of SP-D. Further effects, albeit smaller in magnitude, consisted of reductions in the proportion of airway neutrophils and in MMP-9 content, all with a benefit of improved score in the disease activity assessment test. There were no appreciable changes noted in lung function or dyspnea perception, which could be ascribed to simvastatin treatment. We conclude that statin's anti-inflammatory and surfactant homeostasis preserving properties may offer promise as an adjunctive treatment in COPD patients. The SP-D content in BALF has a potential to become a marker of COPD inflammatory activity and treatment monitoring.

Surfactant protein D is a causal risk factor for COPD: results of Mendelian randomisation

Surfactant protein D (SP-D) is produced primarily in the lung and is involved in regulating pulmonary surfactants, lipid homeostasis and innate immunity. Circulating SP-D levels in blood are associated with chronic obstructive pulmonary disease (COPD), although causality remains elusive.In 4061 subjects with COPD, we identified genetic variants associated with serum SP-D levels. We then determined whether these variants affected lung tissue gene expression in 1037 individuals. A Mendelian randomisation framework was then applied, whereby serum SP-D-associated variants were tested for association with COPD risk in 11 157 cases and 36 699 controls and with 11 years decline of lung function in the 4061 individuals.Three regions on chromosomes 6 (human leukocyte antigen region), 10 (SFTPD gene) and 16 (ATP2C2 gene) were associated with serum SP-D levels at genome-wide significance. In Mendelian randomisation analyses, variants associated with increased serum SP-D levels decreased the risk of COPD (estimate -0.19, p=6.46×10^-03) and slowed the lung function decline (estimate=0.0038, p=7.68×10^-3).Leveraging genetic variation effect on protein, lung gene expression and disease phenotypes provided novel insights into SP-D biology and established a causal link between increased SP-D levels and protection against COPD risk and progression. SP-D represents a very promising biomarker and therapeutic target for COPD.

Trace metals in fluids lining the respiratory system of patients with idiopathic pulmonary fibrosis and diffuse lung diseases

Idiopathic pulmonary fibrosis (IPF) is an interstitial lung disease with a poor prognosis and an undefined etiopathogenesis. Oxidative stress contributes to alveolar injury and fibrosis development and, because transition metals are essential to the functioning of most proteins involved in redox reactions, a better knowledge of metal concentrations and metabolism in the respiratory system of IPF patients may provide a valuable complementary approach to prevent and manage a disease which is often misdiagnosed or diagnosed in later stages. The present review summarizes and discusses literature data on the elemental composition of bronchoalveolar lavage (BAL), induced sputum and exhaled breath condensate (EBC) from patients affected by IPF and healthy subjects. Available data are scanty and the lack of consistent methods for the collection and analysis of lung and airways lining fluids makes it difficult to compare the results of different studies. However, the elemental composition of BAL samples from IPF patients seems to have a specific profile that can be distinguished from that of patients with other interstitial lung diseases (ILD) or control subjects. Suggestions are given towards standard sampling and analytical procedures of BAL samples, in the aim to assess typical element concentration patterns and their potential role as biomarkers of IPF.

Assessment of nanoparticles and metal exposure of airport workers using exhaled breath condensate

Aircraft engine exhaust increases the number concentration of nanoparticles (NP) in the surrounding environment. Health concerns related to NP raise the question of the exposure and health monitoring of airport workers. No biological monitoring study on this profession has been reported to date. The aim was to evaluate the NP and metal exposure of airport workers using exhaled breath condensate (EBC) as a non-invasive biological matrix representative of the respiratory tract. EBC was collected from 458 French airport workers working either on the apron or in the offices. NP exposure was characterized using particle number concentration (PNC) and size distribution. EBC particles were analyzed using dynamic light scattering (DLS) and scanning electron microscopy coupled to x-ray spectroscopy (SEM-EDS). Multi-elemental analysis was performed for aluminum (Al), cadmium (Cd) and chromium (Cr) EBC contents. Apron workers were exposed to higher PNC than administrative workers (p  <  0.001). Workers were exposed to very low particle sizes, the apron group being exposed to even smaller NP than the administrative group (p  <  0.001). The particulate content of EBC was brought out by DLS and confirmed with SEM-EDS, although no difference was found between the two study groups. Cd concentrations were higher in the apron workers (p  <  0.001), but still remained very low and close to the detection limit. Our study reported the particulate and metal content of airport workers airways. EBC is a potential useful tool for the non-invasive monitoring of workers exposed to NP and metals.

Exhaled breath condensate for lung cancer protein analysis: a review of methods and biomarkers

Lung cancer is a leading cause of cancer-related deaths worldwide, and is considered one of the most aggressive human cancers, with a 5 year overall survival of 10-15%. Early diagnosis of lung cancer is ideal; however, it is still uncertain as to what technique will prove successful in the systematic screening of high-risk populations, with the strongest evidence currently supporting low dose computed tomography (LDCT). Analysis of exhaled breath condensate (EBC) has recently been proposed as an alternative low risk and non-invasive screening method to investigate early-stage neoplastic processes in the airways. However, there still remains a relative paucity of lung cancer research involving EBC, particularly in the measurement of lung proteins that are centrally linked to pathogenesis. Considering the ease and safety associated with EBC collection, and advances in the area of mass spectrometry based profiling, this technology has potential for use in screening for the early diagnosis of lung cancer. This review will examine proteomics as a method of detecting markers of neoplasia in patient EBC with a particular emphasis on LC, as well as discussing methodological challenges involving in proteomic analysis of EBC specimens.

Low-dose oral cadmium increases airway reactivity and lung neuronal gene expression in mice

Inhalation of cadmium (Cd) is associated with lung diseases, but less is known concerning pulmonary effects of Cd found in the diet. Cd has a decades-long half-life in humans and significant bioaccumulation occurs with chronic dietary intake. We exposed mice to low-dose CdCl2 (10 mg/L in drinking water) for 20 weeks, which increased lung Cd to a level similar to that of nonoccupationally exposed adult humans. Cd-treated mice had increased airway hyperresponsiveness to methacholine challenge, and gene expression array showed that Cd altered the abundance of 443 mRNA transcripts in mouse lung. In contrast to higher doses, low-dose Cd did not elicit increased metallothionein transcripts in lung. To identify pathways most affected by Cd, gene set enrichment of transcripts was analyzed. Results showed that major inducible targets of low-dose Cd were neuronal receptors represented by enriched olfactory, glutamatergic, cholinergic, and serotonergic gene sets. Olfactory receptors regulate chemosensory function and airway hypersensitivity, and these gene sets were the most enriched. Targeted metabolomics analysis showed that Cd treatment also increased metabolites in pathways of glutamatergic (glutamate), serotonergic (tryptophan), cholinergic (choline), and catecholaminergic (tyrosine) receptors in the lung tissue. Protein abundance measurements showed that the glutamate receptor GRIN2A was increased in mouse lung tissue. Together, these results show that in mice, oral low-dose Cd increased lung Cd to levels comparable to humans, increased airway hyperresponsiveness and disrupted neuronal pathways regulating bronchial tone. Therefore, dietary Cd may promote or worsen airway hyperresponsiveness in multiple lung diseases including asthma.

Extracellular cadmium in the bronchoalveolar space of long-term tobacco smokers with and without COPD and its association with inflammation

Tobacco contains cadmium, and this metal has been attributed a causative role in pulmonary emphysema among smokers, although extracellular cadmium has not to date been quantified in the bronchoalveolar space of tobacco smokers with or without COPD. We determined whether cadmium is enhanced in the bronchoalveolar space of long-term tobacco smokers with or without COPD in vivo, its association with inflammation, and its effect on chemokine release in macrophage-like cells in vitro. Bronchoalveolar lavage (BAL), sputum, and blood samples were collected from current, long-term smokers with and without COPD and from healthy nonsmokers. Cadmium concentrations were determined in cell-free BAL fluid using inductively coupled plasma mass spectrometry. Blood monocyte-derived macrophages were exposed to cadmium chloride in vitro. Depending upon the type of sample, molecular markers of inflammation were quantified either as protein (enzyme-linked immunosorbent assay) or as mRNA (real-time polymerase chain reaction). Cadmium concentrations were markedly increased in cell-free BAL fluid of smokers compared to that of nonsmokers (n=19–29; P<0.001), irrespective of COPD. In these smokers, the measured cadmium displayed positive correlations with macrophage TNF-α mRNA in BAL, neutrophil and CD8⁺ cell concentrations in blood, and finally with IL-6, IL-8, and MMP-9 protein in sputum (n=10–20; P<0.05). The cadmium chloride exposure caused a concentration-dependent increase in extracellular IL-8 protein in monocyte-derived macrophages in vitro. In conclusion, extracellular cadmium is enhanced in the bronchoalveolar space of long-term smokers and displays pro-inflammatory features. Its pathogenic role in tobacco-induced disease deserves further evaluation.

Surfactant protein D, a clinical biomarker for chronic obstructive pulmonary disease with excellent discriminant values

Biological markers can help to better identify a disease or refine its diagnosis. In the present study, the association between surfactant protein D (SP-D) and chronic obstructive pulmonary disease (COPD) was studied among subjects consulting for respiratory diseases or symptoms and was compared with C-reactive protein (CRP) and fibrinogen. A further aim of this study was to identify the optimal cut-off point of SP-D able to discriminate COPD patients. A case-control study including 90 COPD patients, 124 asthma patients and 180 controls was conducted. Standardized questionnaires were administered and lung function tests were performed. Biological markers were measured in blood samples according to standardized procedures. The association between SP-D and COPD was investigated using logistic regression models. Receiver-operating characteristic curves were used for threshold identification. SP-D levels above the median value were positively associated with COPD [adjusted odds ratio (OR)=3.86, 95% confidence interval (CI): 1.51–9.85, P=0.005). No associations with COPD or asthma were found for CRP or fibrinogen levels. Scores for COPD diagnosis in all COPD patients or ever-smoker COPD patients were identified (sensitivity, 76.4 and 77.8%; specificity, 89.3 and 88.5%, respectively). The results indicate that SP-D can differentiate COPD from other respiratory symptoms or diseases. Used with socio-demographic characteristics and respiratory symptoms, SP-D is able to discriminate COPD patients from controls, particularly among smokers.

A Longitudinal Study of Association between Heavy Metals and Itchy Eyes, Coughing in Chronic Cough Patients: Related with Non-Immunoglobulin E Mediated Mechanism

The association between heavy metals exposure and respiratory diseases or allergic sensitization showing high serum immunoglobulin E (IgE) has been suggested. However, previous findings have been inconsistent and the mechanisms responsible remain unclear. We evaluated heavy metal exposure and its association with coughing, itchy eyes in chronic cough patients with different IgE levels. Ninety outpatients in Kanazawa University Hospital were recruited between January-June 2011. Subjects whose total IgE measured by radioimmunosorbent test were asked to record their daily symptoms. We collected daily total suspended particles (TSP) from which concentrations of calcium (Ca), cadmium (Cd), chromium (Cr), iron (Fe), manganese (Mn), nickel (Ni), and lead (Pb) were determined then divided into high and low level groups. Generalized estimating equations were applied to compute the relationship between concentrations of these metals and symptoms. All metals at high levels were significantly associated with itchy eyes compared with low levels, with exception of Ca, the six others were significant in patients with IgE < 250 IU/mL. Cd, Fe, Mn had association with coughing (odds ratio-OR (95% confidence interval-CI): 1.13 (1.03, 1.24), 1.22 (1.05, 1.42), and 1.13 (1.01, 1.27), respectively), this relationship remained significant for Cd (OR (95% CI): 1.14 (1.03, 1.27)) and Mn (OR (95% CI): 1.15 (1.00, 1.31)) in patients with lower IgE. Our findings demonstrate the relationship between aerial heavy metals and itchy eyes, coughing in chronic cough patients, suggesting these symptoms may be due to a non-IgE mediated mechanism.

Beryllium in exhaled breath condensate as a biomarker of occupational exposure in a primary aluminum production plant

OBJECTIVE

Low beryllium exposure can induce pulmonary granulomatosis, so called berylliosis. For occupational health monitoring, it is more relevant to assess the internal dose of Be received by the lungs than urinary or atmospheric Be. Exhaled breath condensate (EBC) is a matrix collected non-invasively that derives from the airway lining fluid. EBC beryllium (Be) levels were evaluated as a marker of occupational exposure in a primary aluminum production plant.

METHODS

We collected urine and EBC from controls and workers recently exposed to beryllium in the pot room and the anode repair sectors, and calculated a cumulative beryllium exposure index (CBEI) summing the number of years of employment in each task and multiplying by the estimated average beryllium exposure for the task. Concentrations of beryllium and aluminum were measured in EBC (Be-EBC and Al-EBC) and in urine (Be-U and Al-U) by ICP-MS.

RESULTS AND CONCLUSION

We have shown that it was possible to measure Be and Al in workers' EBC. Compared with controls and after adjustment for smoking status, levels of Be-EBC and Al-EBC were higher in pot room workers and exposed subjects, respectively. Due to its relationship with CBEI, but not with Be-U, it appears that Be-EBC could be a promising marker of occupational exposure and provide additional toxicokinetic information in occupational health studies.

[Significance of surfactant proteins in the diagnosis of therapeutic diseases]

The lung provides not only respiration, but also the functioning of innate immunity mechanisms. The hydrophilic proteins SP-A and SP-D are responsible for the regulation of the latter. In the literature, there is evidence for elevated serum SP-A and SP-D levels in respiratory diseases accompanied by enhanced mucosal inflammation of the lung or its parenchymal injury and their association with age and cardiovascular diseases has been recently found. Studies of the efficiency of using SP-A and SP-D as specific markers for inflammatory lung diseases are presently worthwhile.

The utility of iron chelators in the management of inflammatory disorders

Since iron can contribute to detrimental radical generating processes through the Fenton and Haber-Weiss reactions, it seems to be a reasonable approach to modulate iron-related pathways in inflammation. In the human organism a counterregulatory reduction in iron availability is observed during inflammatory diseases. Under pathological conditions with reduced or increased baseline iron levels different consequences regarding protection or susceptibility to inflammation have to be considered. Given the role of iron in development of inflammatory diseases, pharmaceutical agents targeting this pathway promise to improve the clinical outcome. The objective of this review is to highlight the mechanisms of iron regulation and iron chelation, and to demonstrate the potential impact of this strategy in the management of several acute and chronic inflammatory diseases, including cancer.