Does exposure to inflammatory particles modify the pattern of anion in exhaled breath condensate?

Exposure to environmental and occupational particulate matter (PM) induces health effects on the cardio-pulmonary system. In addition, associations between exposure to PM and metabolic syndromes like diabetes mellitus or obesity are now emerging in the literature. Collection of exhaled breath condensate (EBC) is an appealing non-invasive technique to sample pulmonary fluids. This hypothesis-generating study aims to (1) validate an ion chromatography method allowing the robust determination of different metabolism-related molecules (lactate, formate, acetate, propionate, butyrate, pyruvate, nitrite, nitrate) in EBC; (2) apply this method to EBC samples collected from workers exposed to quartz (a known inflammatory particle), to soapstone (a less inflammatory particle than quartz), as well as to controls. A multi-compound standard solution was used to determine the linearity range, detection limit, repeatability and bias from spiked EBC. The biological samples were injected without further treatment into an ion chromatograph with a conductivity detector. RTube® were used for field collection of EBC from 11 controls, 55 workers exposed to soapstone and 12 volunteers exposed to quartz dust. The analytical method used proved to be adequate for quantifying eight anions in EBC samples. Its sub-micromolar detection limits and repeatability, combined with a very simple sample preparation, allowed an easy and fast quantification of different glycolysis or nitrosative stress metabolites. Using multivariate discriminant analysis to maximize differences between groups, we observed a different pattern of anions with a higher formate/acetate ratio in the EBC samples for quartz exposed workers compared to the two other groups. We hypothesize that a modification of the metabolic signature could be induced by exposure to inflammatory particles like quartz and might be observed in the EBC via a change in the formate/acetate ratio.

Method validation of nanoparticle tracking analysis to measure pulmonary nanoparticle content: the size distribution in exhaled breath condensate depends on occupational exposure.

A particle exposure assessment based on the dose deposited in the lungs would be the gold standard for the evaluation of any resulting health effects. Measuring particles in exhaled breath condensate (EBC)-a matrix containing water and airway lining fluid-could help to evaluate particle retention in the lungs. This study aimed to (1) validate a nanoparticle tracking analysis (NTA) method for determining the particle number concentration and their hydrodynamic size distribution in EBC, and (2) apply this method to EBC collected from workers exposed to soapstone (n = 55) or quartz dust (n = 12) and controls (n = 11). A standard latex bead solution was used to determine the linear range, limit of detection (LOD), repeatability (coefficient of variation, CV), and bias in spiked EBC. An LM10 NanoSight instrument with NTA version 3.1 software was used for measurement. RTubes® were used for field collection of EBC. The repeatability obtained for a D50 size distribution in EBC showed less than 8% variability, with a bias <7%. The particle concentration was linear in the range ≤2.5 × 108 particles ml-1 with a LOD of 4 × 106 particles ml-1. A recovery of 117 ± 20% at 6.2 × 107 particles ml-1 was obtained with a CV <10% and a bias <20%. EBC from workers exposed to quartz, who experienced the largest exposure to silica particles, consistently exhibited a statistically significant (p < 0.01) higher concentration of particles in their EBC, with a size distribution shift towards larger values than the other groups. Results showed that the NTA technique performed well for characterizing the size distribution and concentrations of particles in EBC. The technique needs to be corroborated with a larger population of workers.

Both exhaled nitric oxide and blood eosinophil count were associated with mild allergic asthma only in non-smokers.

BACKGROUND: The fractional exhaled nitric oxide (FENO) and the blood eosinophil count (B-eos) are markers of eosinophilic inflammation used in the diagnosis and management of asthma. The relationships between smoking cigarette and both FENO and B-eos are complex and raise questions about the association between these markers and asthma in smokers. OBJECTIVE: To determine the relationships between both FENO and B-eos on one hand and asthma and atopy on the other, according to smoking status. METHODS: FENO and B-eos were measured in, respectively, 1579 and 1496 of the 1607 middle-aged adults randomly selected from the general population in the cross-sectional ELISABET survey. Allergic asthma was defined as asthma (a self-report of physician-diagnosed asthma, and wheezing in the previous 12 months or the use of asthma medications) with atopy (allergic rhinitis or hayfever in the previous 12 months, or a previous positive prick test or allergen desensitization therapy). Non-allergic asthma was defined as asthma without atopy. RESULTS: The analysis included 812 (51.4%) never, 473 (30%) former and 294 (18.6%) current smokers. A total of 490 (32%) participants were atopic, 80 (5.1%) had allergic asthma, and 31 (2%) had non-allergic asthma. Only 16.2% (18/111) of asthmatics were treated with glucocorticoid inhalants, suggesting that among them a majority of participants had mild asthma. A positive interaction between smoking status and allergic asthma was observed in multivariate models explaining FENO (P = 0.003) and B-eos (P = 0.001). Thus, compared to those without allergic asthma, participants with allergic asthma had higher FENO values (+ 63.4%, 95% CI = [39; 92]) and higher B-eos (+ 63.2% [38.2; 92.7]) in never and former smokers, but not in current smokers. Lastly, an analysis of receiver-operating characteristic curves showed that each of the two markers was able to discriminate moderately allergic asthma but only in non-smokers. CONCLUSIONS & CLINICAL RELEVANCE: FENO and B-eos were associated with the presence of mild allergic asthma only in non-smokers, not in current smokers. These findings raise questions about the clinical value of FENO and B-eos in smokers.

Emphysema in asymptomatic smokers: quantitative CT evaluation in correlation with pulmonary function tests.

PURPOSE: To provide quantitative information on emphysema in asymptomatic smokers in correlation with pulmonary function tests (PFT). PATIENTS AND METHODS: The study population included 75 smokers (current smokers: n=39; ex-smokers: n=36) and 25 nonsmokers who underwent volumetric high-resolution CT of the chest with automated quantification of emphysema and PFTs. RESULTS: Current smokers had a higher percentage of emphysema in the right lung (P=0.041) and right upper lobe (P=0.037). The overall percentage of emphysema did not differ according to the Gold stage (P=0.77). Smokers with emphysema had significantly higher mean values of FRC (P=0.012), RV (<0.0001) and TLC (P=0.0157) than smokers without emphysema but no significant differences were found in neither the mean values of TLCO nor in expiratory flows (P>0.05). Correlations were found between the percentage of emphysema and (a) cigarette consumption of current (r=0.34215; P=0.0330) and ex-smokers (r=0.44104; P=0.0071); and (b) alterations of TLC, FRC, RV and DLCO of smokers. CONCLUSION: Quantitative CT allows recognition of regional specificities and subclinical functional alterations in smokers with emphysema.

Interest of exhaled biomarkers in occupational asthma to latex: a case report.

New methods for exploring pulmonary inflammation might be useful: measurements of exhaled nitric oxide (NO) and hydrogen peroxide (H(2)O(2)) in exhaled breath condensate (EBC). The authors describe the application and utility of these methods in a case report of pediatric nurse presenting an occupational asthma to latex. Despite compliance with avoidance measures, respiratory discomfort had worsened during work. Classical tests (spirometry, monitoring of peak expiratory flow) were not contributing to objectify the discomfort. Exhaled NO and H(2)O(2) in EBC increased immediately after work periods, compared with rest periods. Application of these new methods, at the same time, in workplace appears useful in the objective demonstration of a temporal relation between work and respiratory problems. The results allowed the occupational physician to transfer the patient to a new work station more appropriate for her respiratory health status.

Cytomegalovirus seroprevalence in exposed and unexposed populations of hospital employees.

The objective of this work was to compare the seroprevalence of cytomegalovirus in an unexposed and exposed population, both working in a hospital, and to study the occupational risk factors related to seropositivity, while taking personal risk factors into account. We conducted a cross-sectional study in a French hospital over a period of 12 months. The overall seroprevalence among the 550 subjects was 49.5%. The multivariate analysis showed that seropositivity was significantly associated with age (36-43 years: odds ratio [OR] = 1.7; 95% confidence interval [CI]: [1.1-2.8]) and working as a pediatric nurse's aide (OR = 1.8; 95% CI: [1.1-2.8]). This study confirms the need to improve prevention procedures in the workplace, including screening, information, and hygiene rules.