Immunoproteomics for Serological Diagnosis of Hypersensitivity Pneumonitis Caused by Environmental Microorganisms.

Diagnosis of immunoallergenic pathologies due to microorganisms such as hypersensitivity pneumonitis includes detection of circulating specific antibodies. Detection of precipitins has classically been performed using immunoprecipitation techniques with crude antigenic extracts from microorganisms implicated as etiologic agents. However, these techniques lack standardization because of the different composition of fungal antigenic extracts from one batch to another. Therefore, there is high interest in developing standardized serological diagnostic methods using recombinant antigens. Immunoproteomics have proved to be useful for identifying the immunogenic proteins in several microorganisms linked to hypersensitivity pneumonitis. With this approach, the causative microorganisms are first isolated from the environment of patients. Then the proteins are separated by two-dimensional electrophoresis and revealed by Western blotting with sera of different patients suffering from the disease compared to sera of asymptomatic exposed controls. Immunoreactive proteins are identified by mass spectrometry. Identified immunoreactive proteins found to be specific markers for the disease could be subsequently produced as recombinant antigens using various expression systems to develop ELISA tests. Using recombinant antigens, standardized ELISA techniques can be developed, with sensitivity and specificity reaching 80% and 90%, respectively, and more if using a combination of several antigens. Immunoproteomics can be applied to any environmental microorganisms, with the aim of proposing panels of recombinant antigens able to improve the sensitivity and standardization of serologic diagnosis of hypersensitivity pneumonitis, but also other mold-induced allergic diseases such as allergic broncho pulmonary aspergillosis or asthma.

Evaluation of the inhalation technique in asthmatic children visiting a specialised outpatient clinic

Background and objective: Asthma is one of the most frequent chronic diseases affecting children and adolescents. Good compliance is indispensable for effective treatment since a suboptimal use of inhalation devices can result in decreased therapeutic efficacy and increased morbidity. The objective of this work was to evaluate the inhalation technique of paediatric patients visiting a specialized consultation clinic of a university hospital. Design: Observational prospective study during a 3-month period. Setting Specialized consultation clinic of a university hospital. Main outcome measures: This study involved 40 outpatient infants, children and adolescents visiting alone or with their parent(s). Patients' data (age, sex, weight, diagnostic, reason for consulting, previous consultations) and their medicines were compiled using an ad hoc form. Filmed sequences of the inhalation procedure used by each child were reviewed independently by members of an interdisciplinary team consisting in a physician, a pharmacist, a nurse and a physiotherapist. A score of 1 was assigned to each correct step in the procedure, and a score of 0 to an incorrect step. A perfect procedure implied 12 correct steps. Results: Thirty patients were treated with a metered-dose inhaler and an inhalation chamber (Babyhaler or AeroChamber Plus); ten other patients were treated with a dry powder inhaler (Diskus or Turbuhaler). The agreement between the members of the interdisciplinary team was considered satisfactory. Nine patients (22.5%) reached an average score lower than 7, 18 patients (45%) a score between 7 and 10 and 13 (32.5%) a score equal to or better than 10. No patient reached the maximum score of 12. Users of the metered-dose inhalers (average score = 9.2) showed a better technique than users of the dry powder inhalers (average score = 7.4). Disappointingly, the score was not improved during a second consultation or following regular consultations. Conclusions: Video recording is a simple method to evaluate the degree of mastery of an inhalation procedure in paediatric patients. The method allows a convenient and efficient identification of suboptimal procedure steps by the hospital staff, and opens the way to patient-specific teaching. In two-thirds of juvenile patients, their inhalation technique was suboptimal despite initial training. This study shows conclusively that the inhalation technique in paediatric patients must be monitored during each examination, and teaching measures taken to improve it when necessary.

Thymic stromal lymphopoietin plays divergent roles in murine models of atopic and nonatopic airway inflammation.

BACKGROUND: Thymic stromal lymphopoietin (TSLP) is a cytokine primarily produced by epithelial cells, which has been shown to be a potent inducer of T-helper 2 (Th2)-type responses. However, TSLP has pleiotropic effects upon immune cells, and although extensively studied in the context of atopic asthma, its relevance as a therapeutic target and its role in the pathogenesis of nonatopic asthma remains unknown. We sought to investigate the role of TSLP in atopic, nonatopic and viral-induced exacerbations of pulmonary inflammation. METHODS: Using stringently defined murine models of atopic, nonatopic and virally exacerbated forms of pulmonary inflammation, we compared inflammatory responses of C57BL/6 wild-type (WT) and TSLP receptor-deficient (TSLPR KO) mice. RESULTS: Thymic stromal lymphopoietin receptor (TSLPR) signaling was crucial for the development of atopic asthma. Specifically, TSLPR signaling to lung recruited CD4+ T cells enhanced eosinophilia, goblet cell hyperplasia, and overall inflammation within the airways. In contrast, the absence of TSLPR signaling was associated with strikingly exaggerated pulmonary neutrophilic inflammation in a nonatopic model of airway inflammation. The inflammation was associated with excessive levels of interleukin (IL)-17A in the lungs, indicating that TSLP negatively regulates IL-17A. In addition, in a model of influenza-induced exacerbation of atopic airway inflammation, the absence of TSLPR signaling also led to exaggerated neutrophilic inflammation. CONCLUSION: Thymic stromal lymphopoietin plays divergent roles in the pathogenesis of atopic and nonatopic asthma phenotypes by either enhancing Th2 responses or curtailing T-helper 17 responses. These findings raise important caveats for the design of therapeutic interventions targeting TSLP in asthma.

Impact d'une école de l'asthme sur la consommation en soins et la qualité de vie des enfants de 4 à 12 ans et de leurs parents

L'article a été réalisé en collaboration avec Marie-Elise Verga, infirmière de recherche au DMCP, il a été publié dans les Archives de Pédiatrie, une revue française d'importance pour la profession en novembre 2013. L'impact factor de la revue est de 0.36. Ce travail est centré sur l'évaluation de l'impact d'une école de l'asthme chez l'enfant. L'asthme est la maladie chronique la plus fréquente chez l'enfant, sa prévalence est en augmentation dans le monde depuis plusieurs années. Son impact sur la vie des enfants atteints et de leur famille est important en termes d'absentéisme et de limitation dans les activités de la vie quotidienne. Selon différentes études, la connaissance de la maladie serait un pilier pour l'amélioration de son contrôle. Associée à des compétences personnelles et une médication optimale, elle diminuerait les absences scolaires, la survenue des crises et augmenterait la compliance au traitement. L'Ecole de l'Asthme de l'Hôpital de l'Enfance à Lausanne a été mise en place dans ce but, afin d'offrir, par une équipe pluridisciplinaire, des séances d'éducation thérapeutique tant aux enfants qu'à leur famille. Notre étude exploratoire a pour but d'évaluer l'effet de l'Ecole de l'Asthme sur la consommation en soins et la qualité de vie des enfants de 4 à 12 ans et de leurs parents. 27 enfants ont été inclus durant une année. La qualité de vie a été évaluée chez les enfants et leurs parents au moyen du Paediatric Asthma Quality of Life Questionnaire à l'inclusion et 6 mois plus tard. La consommation en soins a été évaluée sur une période d'un an avant et après l'Ecole de l'asthme par un questionnaire envoyé aux pédiatres. Il s'agit de la première étude de ce genre en Suisse et il y en a très peu à l'étranger. Elle démontre clairement une diminution de la consommation en soins que ce soit les rendez- vous chez le pédiatre, les consultations aux urgences et les hospitalisations. Une amélioration de la qualité de vie retrouvée tant chez les enfants que leurs parents a aussi été observée lors de notre étude. En donnant aux enfants et à leur famille des moyens de mieux gérer la maladie à domicile, l'Ecole de l'Asthme contribue à un meilleur contrôle de cette maladie. Ces premières conclusions valident l'importance d'évaluer cette prise en charge par des études prospectives randomisées. Il existe plusieurs perspectives à développer dans le prolongement de cette étude par exemple inclure des patients non francophones, sachant que les migrants représentent une part importante des consultations en urgences et que leur maladie asthmatique est souvent mal contrôlée. Il faudrait affiner les résultats en comparant nos résultats à ceux d'un groupe contrôle ou d'un groupe avec un enseignement individualisé. Un suivi sur 5 ans permettrait de voir l'impact à long terme. Le côté financier devrait être évalué afin de vérifier la diminution des coûts supposée en rapport à la diminution de la consommation en soins.

The prevalence of accentuated palmoplantar markings and keratosis pilaris in atopic dermatitis, autosomal dominant ichthyosis and control dermatological patients.

The prevalence of keratosis pilaris and accentuated palmoplantar marking was evaluated in 61 patients with atopic dermatitis, 35 patients with dominant ichthyosis vulgaris and 247 other dermatological cases taken as controls. Our data showed that (1) these features are of no diagnostic significance for atopic dermatitis and (2) they are significantly more frequent in patients with ichthyosis vulgaris without associated eczema than in those with atopic dermatitis. Consequently, they should be considered as part of the phenotype of ichthyosis vulgaris rather than attributed to a concomitant atopic dermatitis as suggested by some. These findings should be taken into account when evaluating atopic dermatitis or ichthyosis. To assess the frequency of scaling under winter weather conditions, 155 control subjects were also examined for evidence of visible desquamation and 25.8% showed slight but definite scaling.

Platelet-activating factor causes ventilation-perfusion mismatch in humans

We hypothesized that platelet-activating factor (PAF), a potent inflammatory mediator, could induce gas exchange abnormalities in normal humans. To this end, the effect of aerosolized PAF (2 mg/ml solution; 24 micrograms) on ventilation-perfusion (VA/Q) relationships, hemodynamics, and resistance of the respiratory system was studied in 14 healthy, nonatopic, and nonsmoking individuals (23 +/- 1 [SEM]yr) before and at 2, 4, 6, 8, 15, and 45 min after inhalation, and compared to that of inhaled lyso-PAF in 10 other healthy individuals (24 +/- 2 yr). PAF induced, compared to lyso-PAF, immediate leukopenia (P < 0.001) followed by a rebound leukocytosis (P < 0.002), increased minute ventilation (P < 0.05) and resistance of the respiratory system (P < 0.01), and decreased systemic arterial pressure (P < 0.05). Similarly, compared to lyso-PAF, PaO2 showed a trend to fall (by 12.2 +/- 4.3 mmHg, mean +/- SEM maximum change from baseline), and arterial-alveolar O2 gradient increased (by 16.7 +/- 4.3 mmHg) (P < 0.02) after PAF, because of VA/Q mismatch: the dispersion of pulmonary blood flow and that of ventilation increased by 0.45 +/- 0.1 (P < 0.01) and 0.29 +/- 0.1 (P < 0.04), respectively. We conclude that in normal subjects, inhaled PAF results in considerable immediate VA/Q inequality and gas exchange impairment. These results reinforce the notion that PAF may play a major role as a mediator of inflammation in the human lung.

Mitochondrial fatty acid oxidation in obesity

Significance: Current lifestyles with high-energy diets and little exercise are triggering an alarming growth in obesity. Excess of adiposity is leading to severe increases in associated pathologies, such as insulin resistance, type 2 diabetes, atherosclerosis, cancer, arthritis, asthma, and hypertension. This, together with the lack of efficient obesity drugs, is the driving force behind much research. Recent Advances: Traditional anti-obesity strategies focused on reducing food intake and increasing physical activity. However, recent results suggest that enhancing cellular energy expenditure may be an attractive alternative therapy. Critical Issues: This review evaluates recent discoveries regarding mitochondrial fatty acid oxidation (FAO) and its potential as a therapy for obesity. We focus on the still controversial beneficial effects of increased FAO in liver and muscle, recent studies on how to potentiate adipose tissue energy expenditure, and the different hypotheses involving FAO and the reactive oxygen species production in the hypothalamic control of food intake. Future Directions: The present review aims to provide an overview of novel anti-obesity strategies that target mitochondrial FAO and that will definitively be of high interest in the future research to fight against obesity-related disorders.

Platelet-activating factor causes ventilation-perfusion mismatch in humans

We hypothesized that platelet-activating factor (PAF), a potent inflammatory mediator, could induce gas exchange abnormalities in normal humans. To this end, the effect of aerosolized PAF (2 mg/ml solution; 24 micrograms) on ventilation-perfusion (VA/Q) relationships, hemodynamics, and resistance of the respiratory system was studied in 14 healthy, nonatopic, and nonsmoking individuals (23 +/- 1 [SEM]yr) before and at 2, 4, 6, 8, 15, and 45 min after inhalation, and compared to that of inhaled lyso-PAF in 10 other healthy individuals (24 +/- 2 yr). PAF induced, compared to lyso-PAF, immediate leukopenia (P < 0.001) followed by a rebound leukocytosis (P < 0.002), increased minute ventilation (P < 0.05) and resistance of the respiratory system (P < 0.01), and decreased systemic arterial pressure (P < 0.05). Similarly, compared to lyso-PAF, PaO2 showed a trend to fall (by 12.2 +/- 4.3 mmHg, mean +/- SEM maximum change from baseline), and arterial-alveolar O2 gradient increased (by 16.7 +/- 4.3 mmHg) (P < 0.02) after PAF, because of VA/Q mismatch: the dispersion of pulmonary blood flow and that of ventilation increased by 0.45 +/- 0.1 (P < 0.01) and 0.29 +/- 0.1 (P < 0.04), respectively. We conclude that in normal subjects, inhaled PAF results in considerable immediate VA/Q inequality and gas exchange impairment. These results reinforce the notion that PAF may play a major role as a mediator of inflammation in the human lung.

Pediatric and adult eosinophilic esophagitis: similarities and differences.

Early in the 1990s, several case series described adults suffering from dysphagia and children with refractory reflux symptoms, both accompanied by an eosinophil-predominant infiltration, thereby conclusively distinguishing it from gastroesophageal reflux disease. Eosinophilic esophagitis (EoE) was recognized as its own entity in the adult and in the pediatric literature. In the last decade, evidence has accumulated that EoE represents a T-helper (Th)2-type inflammatory disease. Remodeling of the esophagus is a hallmark of EoE, leading to esophageal dysfunction and bolus impaction. Familial occurrence and disease association with single-nucleotide polymorphisms underscore the influence of genetics in this disease. Eosinophilic esophagitis may affect individuals at any age, although the clinical presentation is highly age dependent. There is a significant allergic bias in the EoE population, with the majority of patients having concurrent allergic rhinitis, asthma, eczema, and/or a history of atopy. One noteworthy difference is that in children, EoE seems to be primarily a food antigen-driven disease, whereas in adults, mainly aeroallergen sensitization has been observed. Treatment modalities for EoE include the 3Ds: drugs, diet, and dilation. The crucial question of whether adult and pediatric EoE are different phenotypes of one single entity or whether we are confronted with two different diseases is still open. Here, we review similarities and differences between EoE in adults and children.

Tabagisme passif et santé respiratoire de l'adulte: une menace bien réelle [ETS and respiratory health in adults: a real threat]

Hazards due to active smoking are known for a long time. On the other hand, the importance of the harmful effects of passive smoking are less recognized, having been shown initially mainly in the pediatric population. However, the importance of significant increased risks on various respiratory pathologies of the adult are well known today, in a Swiss society where the number of active smokers remains high, leading to a high prevalence of passive smoking exposure On the basis of recent publications and updates of various organizations, we propose a review of the history, noxious mechanisms and effects on various respiratory pathologies of the exposure to passive smoke in adults.

Affections pulmonaires et attitude [High altitude and preexisting lung diseases].

Today, a growing number of people, some of them suffering from lung diseases, travel to high altitude resorts. It is sometimes not easy for the general practitioner to adequately counsel these patients. Based on our knowledge of physiopathology and clinical studies, the present paper addresses the effects of high altitude in patients with preexisting lung diseases and provides recommendations in order to optimize the sojourn at high altitude.

Evaluation of respiratory and dermal occupational exposures to monoethanolamine during cleaning

Professional cleaning is a basic service occupation with a wide variety of tasks carried out in all kind of different sectors and workplaces by a large workforce. One important risk for cleaning workers is the exposure to chemical substances that are present in cleaning products.Monoethanolamine was found to be often present in cleaning products such as general purpose cleaners, bathroom cleaners, floor cleaners and kitchen cleaners. Monoethanolamine can injure the skin, and exposure to monoethanolamine was associated to asthma even when the air concentrations were low. It is a strong irritant and known to be involved in sensitizing mechanisms. It is very likely that the use of cleaning products containing monoethanolamine gives rise to respiratory and dermal exposures. Therefore there is a need to further investigate the exposures to monoethanolamine for both, respiratory and dermal exposure.The determination of monoethanolamine has traditionally been difficult and analytical methods available are little adapted for occupational exposure assessments. For monoethanolamine air concentrations, a sampling and analytical method was already available and could be used. However, a method to analyses samples for skin exposure assessments as well as samples of skin permeation experiments was missing. Therefore one main objective of this master thesis was to search an already developed and described analytical method for the measurement of monoethanolamine in water solutions, and to set it up in the laboratory. Monoethanolamine was analyzed after a derivatisation reaction with o-pthtaldialdehyde. The derivated fluorescing monoethanolamine was then separated with high performance liquid chromatography and detection took place with a fluorescent detector. The method was found to be suitable for qualitative and quantitative analysis of monoethanolamine. An exposure assessment was conducted in the cleaning sector to measure the respiratory and dermal exposures to monoethanolamine during floor cleaning. Stationary air samples (n=36) were collected in 8 companies and samples for dermal exposures (n=12) were collected in two companies. Air concentrations (Mean = 0.18 mg/m3, Standard Deviation = 0.23 mg/m3, geometric Mean = 0.09 mg/m3, Geometric Standard Deviation = 3.50) detected were mostly below 1/10 of the Swiss 8h time weighted average occupational exposure limit. Factors that influenced the measured monoethanolamine air concentrations were room size, ventilation system and the concentration of monoethanolamine in the cleaning product and amount of monoethanolamine used. Measured skin exposures ranged from 0.6 to 128.4 mg/sample. Some cleaning workers that participated in the skin exposure assessment did not use gloves and had direct contact with the solutions containing the cleaning product and monoethanolamine. During the entire sampling campaign, cleaning workers mostly did not use gloves. Cleaning workers are at risk to be regularly exposed to low air concentrations of monoethanolamine. This exposure may be problematic if a worker suffers from allergic reactions (e.g. Asthma). In that case a substitution of the cleaning product may be a good prevention measure as several different cleaning products are available for similar cleaning tasks. Currently there are no occupational exposure limits to compare the skin exposures that were found. To prevent skin exposures, adaptations of the cleaning techniques and the use of gloves should be considered. The simultaneous skin and airborne exposures might accelerate adverse health effects. Overall the risks caused by exposures to monoethanolamine are considered as low to moderate when the cleaning products are used correctly. Whenever possible, skin exposures should be avoided. Further research should consider especially the dermal exposure routes, as very high exposures might occur by skin contact with cleaning products. Dermatitis but also sensitization might be caused by skin exposures. In addition, new biomedical insights are needed to better understand the risks of the dermal exposure. Therefore skin permeability experiments should be considered.

TRPM5-mediated calcium uptake regulates mucin secretion from human colon goblet cells

Mucin 5AC (MUC5AC) is secreted by goblet cells of the respiratory tract and, surprisingly, also expressed de novo in mucus secreting cancer lines. siRNA-mediated knockdown of 7343 human gene products in a human colonic cancer goblet cell line (HT29-18N2) revealed new proteins, including a Ca(2+)-activated channel TRPM5, for MUC5AC secretion. TRPM5 was required for PMA and ATP-induced secretion of MUC5AC from the post-Golgi secretory granules. Stable knockdown of TRPM5 reduced a TRPM5-like current and ATP-mediated Ca(2+) signal. ATP-induced MUC5AC secretion depended strongly on Ca(2+) influx, which was markedly reduced in TRPM5 knockdown cells. The difference in ATP-induced Ca(2+) entry between control and TRPM5 knockdown cells was abrogated in the absence of extracellular Ca(2+) and by inhibition of the Na(+)/Ca(2+) exchanger (NCX). Accordingly, MUC5AC secretion was reduced by inhibition of NCX. Thus TRPM5 activation by ATP couples TRPM5-mediated Na(+) entry to promote Ca(2+) uptake via an NCX to trigger MUC5AC secretion