Environmental and occupational disordersCharacterization of airway inflammation after repeated exposures to occupational agents☆,☆☆
Section snippets
Study design
We recruited subjects with OA previously diagnosed by using specific inhalation challenges (SICs) in whom the dose of occupational agent necessary to induce an asthmatic reaction was determined. On the first day (control day), they were given a questionnaire regarding their respiratory symptoms, smoking habits, and current treatment for asthma. On day 2, subjects were exposed to half the dose of occupational agent that induced an asthmatic reaction at the time of the diagnosis. On day 3,
Results
Twenty-seven subjects were enrolled, but 12 were excluded because they experienced an asthmatic reaction the first day of exposure (n = 6), did not experience any reaction (n = 3), or did not wish to continue their participation (n = 3). The study protocol was completed in 15 subjects. The clinical characteristics of these subjects are listed in Table I.
Patient No. Sex Age (y) Smoking* (duration of cessation) Atopy† Agent Duration of exposure (y) Time between
Discussion
We observed an increase in inflammatory indices associated with eosinophilic infiltration (sputum eosinophils, IL-5, and eotaxin mRNA+ cells) that preceded any significant change in functional parameters (FEV1 and PC20) in subjects with OA after exposure to occupational sensitizers. These findings are consistent with observations previously made in patients with asthma in whom an increase in sputum eosinophils precedes the occurrence of asthma exacerbations25, 26 and in whom a low dose of
Acknowledgements
We thank Drs André Cartier and Jean-Luc Malo for reviewing the article.
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Cited by (0)
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Supported by Institut de Recherche en Santé et Sécurité au Travail (IRSST). C. Lemière and Q. Hamid are scholars of the Fonds de la recherche en santé du Québec.
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Reprint requests: Catherine Lemière, MD, Department of Chest Medicine, Sacré-Coeur Hospital, 5400 West Gouin, Montreal, Quebec, Canada, H4J 1C5.