L’expectoration induite, outil de diagnostic de l’asthme professionnel

Le diagnostic de l’asthme professionnel (AP) repose essentiellement sur la mise en évidence de changements fonctionnels respiratoires consécutifs à une exposition à des agents présents en milieu de travail. L’expectoration induite permet d’évaluer de façon répétée l’inflammation bronchique de la plupart des sujets victimes d’un AP. Ceux-ci présentent, pour la plupart, une éosinophilie bronchique lors de l’exposition à l’agent causal de leur AP. Cette éosinophilie disparaît ou diminue quand les sujets ne sont plus exposés à l’agent qui induit l’AP. Elle se manifeste également lorsque ces patients sont exposés en laboratoire à l’agent professionnel en cause. La persistance d’une inflammation bronchique chez les sujets atteints d’AP, que l’on a soustraits à l’agent à l’origine de leur maladie, pourrait être un facteur de mauvais pronostic. Le recours à l’expectoration induite est, à notre point de vue, un outil utile dans le diagnostic et le suivi de l’AP. Son rôle dans la surveillance de travailleurs à risque d’être victime de l’AP reste cependant à être déterminé.The diagnosis of occupational asthma relies mainly on the demonstration of changes in airway calibre and airway responsiveness after exposure to occupational agents in the laboratory or at the workplace. However, spirometry or peak expiratory flow measurements may be open to misinterpretation when they are not performed optimally. As in non-occupational asthma, airway inflammation is one of the main characteristics of occupational asthma. Induced sputum, a non invasive method to assess airway inflammation, has been successfully used in the management of asthma. This article reviews the studies that have investigated and characterized the changes in sputum cell counts occurring in subjects with occupational asthma after exposure to occupational agents in the laboratory or at the workplace in order to assess the place of induced sputum in the investigation of occupational asthma. It also reviews the use of induced sputum during the follow-up of workers with occupational asthma after removal from exposure. This article also describes a new condition identified thanks to the use of induced sputum : occupational eosinophilic bronchitis. In conclusion, induced sputum is a useful tool in the investigation of occupational asthma. Its use on a regular basis in the investigation of occupational asthma also allows for the possibility of diagnosis of overlooked conditions such as occupational eosinophilic bronchitis. Its role in the surveillance of workers at risk to develop occupational asthma remains to be determined

Predictive value of nonspecific bronchial responsiveness in occupational asthma

BACKGROUND: The diagnosis of occupational asthma (OA) can be challenging and needs a stepwise approach. However, the predictive value of the methacholine challenge has never been addressed specifically in this context. OBJECTIVE: We sought to evaluate the sensitivity, specificity, and positive and negative predictive values of the methacholine challenge in OA. METHODS: A Canadian database was used to review 1012 cases of workers referred for a suspicion of OA between 1983 and 2011 and having had a specific inhalation challenge. We calculated the sensitivity, specificity, and positive and negative predictive values of methacholine challenges at baseline of the specific inhalation challenge, at the workplace, and outside work. RESULTS: At baseline, the methacholine challenge showed an overall sensitivity of 80.2% and a specificity of 47.1%, with positive and negative predictive values of 36.5% and 86.3%, respectively. Among the 430 subjects who were still working, the baseline measures displayed a sensitivity of 95.4%, a specificity of 40.1%, and positive and negative predictive values of 41.1% and 95.2%, respectively. Among the 582 subjects tested outside work, the baseline measures demonstrated a sensitivity and specificity of 66.7% and 52%, respectively, and positive and negative predictive values of 31.9% and 82.2%, respectively. When considering all subjects tested by a methacholine challenge at least once while at work (479), the sensitivity, specificity, and positive and negative predictive values were 98.1%, 39.1%, and 44.0% and 97.7%, respectively. CONCLUSION: A negative methacholine challenge in a patient still exposed to the causative agent at work makes the diagnosis of OA very unlikely

Benefits of low-dose inhaled fluticasone on airway response and inflammation in mild asthma

SummaryRationaleCurrent guidelines suggest that asthma should be controlled with the lowest dose of maintenance medication required.ObjectivesTo evaluate the effects of a low dose of inhaled corticosteroid compared to a placebo, on airway inflammation and responsiveness in patients with mild symptomatic asthma.MethodsIn this randomized double-blind, placebo-controlled, parallel group study, we looked at the influence of inhaled fluticasone propionate 250μg/day for 3 months followed by 100μg/day for 9 months on airway inflammation and methacholine responsiveness in non-smoking subjects with mild allergic asthma. Subjects were evaluated at baseline and 3, 6, 9 and 12 months after treatments; a 2-week evaluation of respiratory symptoms and peak expiratory flow measurements was done before each visit.ResultsFifty-seven subjects completed the 3-month study period. Airway responsiveness, expressed as the PC20 methacholine, increased by 0.27 and 1.14 doubling concentrations, respectively, in placebo-treated (n=33) and in fluticasone-treated (n=24) asthmatic subjects (p=0.03). An additional improvement in PC20 up to 2.16 doubling concentrations was observed in the fluticasone-treated group during the 9-month lower-dose treatment (p=0.0004, end of low-dose period compared with placebo). Sputum eosinophil counts decreased after 3 months of fluticasone 250μg/day compared with placebo (p<0.0001) and remained in the normal range during the 9-month lower-dose treatment. Respiratory symptoms and peak expiratory flows did not change significantly throughout the study in both groups.ConclusionIn mild asthma, keeping a regular minimal dose of ICS after asthma control has been achieved, may lead to a further reduction in airway responsiveness and keep sputum eosinophil count within the normal range

2003 Canadian Asthma Consensus Guidelines Executive Summary

<p>Abstract</p> <p>Background</p> <p>Guidelines for the diagnosis and management of asthma have been published over the last 15 years; however, there has been little focus on issues relating to asthma in childhood. Since the last revision of the 1999 Canadian Asthma Consensus Report, important new studies, particularly in children, have highlighted the need to incorporate new information into the asthma guidelines. The objectives of this article are to review the literature on asthma published between January 2000 and June 2003 and to evaluate the influence of new evidence on the recommendations made in the 1999 Canadian Asthma Consensus Report and its 2001 update, with a major focus on pediatric issues.</p> <p>Methods</p> <p>The diagnosis of asthma in young children and prevention strategies, pharmacotherapy, inhalation devices, immunotherapy, and asthma education were selected for review by small expert resource groups. The reviews were discussed in June 2003 at a meeting under the auspices of the Canadian Network For Asthma Care and the Canadian Thoracic Society. Data published through December 2004 were subsequently reviewed by the individual expert resource groups.</p> <p>Results</p> <p>This report evaluates early-life prevention strategies and focuses on treatment of asthma in children, emphasizing the importance of early diagnosis and preventive therapy, the benefits of additional therapy, and the essential role of asthma education.</p> <p>Conclusion</p> <p>We generally support previous recommendations and focus on new issues, particularly those relevant to children and their families. This document is a guide for asthma management based on the best available published data and the opinion of health care professionals, including asthma experts and educators.</p

L'imaginaire urbain dans les régions ouvrières en reconversion: Le bassin stéphanois et le bassin minier du Nord Pas de Calais

Cette recherche est une recherche sociologique et anthropologique coordonnée par Michel Rautenberg rassemblant le Centre Max Weber de Saint-Étienne, le Centre Lillois d'études et de recherches sociologiques et économiques (sous la responsabilité du professeur Licia Valladarès) et l' Université de Sofia (sous la responsabilité du professeur Ivaylo Ditchev). Démarrée en décembre 2007 elle s'est terminée en avril 2011 et a bénéficié d'une aide de l'ANR de 180 k€ pour un montant global de 250 k€ de subventions publiques (non comprise une allocation de recherche).The general hypothesis at the origin of this research is that urban transformations do not go without social representations and the field of the imagination. It is essential for each image, word or story to be related to concrete situations that the researcher can describe. The choice of cities is thus not negligible. In this research programme, it has focussed on cities which have a had a difficult economic history characterised by brutal de-industrialization - more in people's minds than by its suddenness. This has left a traumatic effect on individual and collective memories, an urban landscape of industrial wasteland and 3 decades later it continues to strongly influence urban renovation policies. The first issue of this research, which in its second phase was extended to include Bulgarian cities thanks to the support of the Ministry for Foreign Affairs, was to establish a method making it possible to describe this imagination. So researchers agreed to work on imagination "operators", that is to say means (administrative, artistic or social) used by socially identified actors : artists, associations, inhabitants, former miners, municipal authorities. The second issue was to favour the imagination of cites which cannot be measured against communication strategies but which considers the "popular" social imagination which is sufficiently autonomous to exist outside municipal institutions - without asserting that it is completely independent. The third issue was to find common features in the comparison between situations close enough in their history to justify a pertinent comparison.L'hypothèse générale à l'origine de cette recherche est que les transformations urbaines ne font pas l'économie des représentations et des imaginaires sociaux. Il est donc nécessaire que chaque image, parole ou récit recueilli soit rapporté à des situations concrètes que le chercheur peut décrire. Le choix des villes n'est alors pas anodin. Dans ce programme de recherche, il s'est porté sur des villes qui ont eu une histoire économique difficile caractérisée par une désindustrialisation brutale -dans les esprits peut-être plus que par sa soudaineté. Celle ci a laissé des traumatismes dans les mémoires individuelles et collectives, un paysage urbain de friches industrielles, et continue après 3 décennies d'influencer fortement sur les politiques de rénovation urbaine

Canadian guidelines for clinical practice: an analysis of their quality and relevance to the care of adults with comorbidity

<p>Abstract</p> <p>Background</p> <p>Clinical guidelines have been the subject of much criticism in primary care literature partly due to potential conflicts in their implementation among patients with multiple chronic conditions. We assessed the relevance of selected Canadian clinical guidelines on chronic diseases for patients with comorbidity and examined their quality.</p> <p>Methods</p> <p>We selected 16 chronic medical conditions according to their frequency of occurrence, complexity of treatment, and pertinence to primary care. Recent Canadian clinical guidelines (2004 - 2009) on these conditions, published in English or French, were retrieved. We assessed guideline relevance to the care of patients with comorbidity with a tool developed by Boyd and colleagues. Quality was assessed using the Appraisal of Guidelines Research and Evaluation (AGREE) instrument.</p> <p>Results</p> <p>Regarding relevance, 56.2% of guidelines addressed treatment for patients with multiple chronic conditions and 18.8% addressed the issue for older patients. Fifteen guidelines (93.8%) included specific recommendations for patients with one concurrent condition; only three guidelines (18.8%) addressed specific recommendations for patients with two comorbid conditions and one for more than two concurrent comorbid conditions. Quality of the evaluated guidelines was good to very good in four out of the six domains measured using the AGREE instrument. The domains with lower mean scores were Stakeholder Involvement and Applicability.</p> <p>Conclusions</p> <p>The quality of the Canadian guidelines examined is generally good, yet their relevance for patients with two or more chronic conditions is very limited and there is room for improvement in this respect.</p

When to Suspect Occupational Asthma

Occupational asthma (OA) is a difficult diagnosis to make. The present review describes the work environments in which workers are at risk for developing OA, the characteristics of the individuals in whom OA should be suspected and the investigation that can be performed to diagnose the condition. Accurately diagnosing OA is crucial because of the major social and economic consequences of this diagnosis on the patient

A Comparison of Work-Exacerbated Asthma Cases from Clinical and Epidemiological Settings

BACKGROUND: Clinical and epidemiological studies commonly use different case definitions in different settings when investigating work-exacerbated asthma (WEA). These differences are likely to impact characteristics of the resulting WEA cases