Towards a better understanding of work-aggravated asthma

工作加重哮喘(WAA)是一种到目前为止被忽视的常见疾病。这项计划的广泛目标是改善对WAA的诊断，并评估这种疾病的社会经济负担。为了实现这一目标，我们提出了以下具体目标。1.评估WAA患者在两个专科门诊每年转诊的可能与工作相关的哮喘患者中所占比例。2.比较WAA组、职业性哮喘(OA)组和非WAA和OA的哮喘组在工作和非工作期间的临床、功能和炎症特征。3.根据工作场所接触特定物质的情况，评估发生WAA或OA的风险。4.比较WAA、OA和哮喘患者2年以上的临床功能和炎症结果，并建立WAA的预后因素。5.从工作残疾和卫生资源使用两方面评估WAA的经济影响。方法：研究方法。这项研究的第一部分将采用交叉设计，共3组，每组60人，每组工作两周，休息两周：患有骨性关节炎的受试者、患有WAA的受试者和没有WAA或OA的哮喘患者。在每段时间结束时，他们将接受乙酰甲胆碱挑战和痰诱导。下一步，将对患有工作相关性哮喘的受试者进行特定的吸入挑战，以区分OA和WAA。将进行病例对照研究，以评估哪种类型的职业诱因可能诱发WAA。这项研究的第二部分将包括一项队列研究，对患有OA、WAA的受试者和没有OA而不是WAA的哮喘患者进行为期两年的随访。每年对受试者进行肺活量测定、乙酰甲胆碱激发和诱导痰检查，为期2年。哮喘恶化的发生将被记录下来。WAA的经济影响将根据工作残疾和卫生资源的使用情况进行评估，并与没有Oa的Oa和哮喘进行比较，而不是WAA。

Work-aggravated asthma (WAA) is a frequent condition that has been so far overlooked. The broad objective of this program is to improve the diagnosis of WAA and to assess the socio-economic burden of this disease. In order to reach this objective, we propose the following specific aims. 1.To evaluate the proportion of subjects with WAA among the subjects who are referred yearly for possible work-related asthma in two clinics specialized in this field. 2.To compare the clinical, functional and inflammatory characteristics of subjects with WAA, occupational asthma (OA), and asthmatic subjects without WAA nor OA during periods at work and away from work. 3.To evaluate the risk of developing WAA or OA according to the exposure to specific agents at the workplace. 4.To compare the clinical functional and inflammatory outcome of subjects with WAA, OA and asthmatics without WAA nor OA over 2 years and establish prognostic factors for WAA 5.To assess the economic impact of WAA in terms of work disability and use of health resources. Methods. The first part of the study will be of crossover design, with periods of 2 weeks at work and 2 weeks away from work for 3 groups of 60 subjects: subjects with OA, subjects with WAA and asthmatics without WAA nor OA. At the end of each period of time, they will undergo a methacholine challenge and a sputum induction. Next, a specific inhalation challenge will be performed in subjects with work-related asthma to differentiate OA from WAA. Case-control studies will be performed in order to assess which type of occupational agents are likely to induce WAA. The second part of the study will consist in a cohort study with a two-year follow-up of the subjects with OA, WAA and asthmatics without OA not WAA. The subjects will be followed yearly for 2 years by spirometry, methacholine challenge and sputum induction. The occurrence of asthma exacerbations will be recorded. The economic impact of WAA will be assessed in terms of work disability and use of health resources and compared with OA and asthma without OA not WAA.