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Characterization of airway inflammation after repeated exposures to occupational agents

2000; Elsevier BV; Volume: 106; Issue: 6 Linguagem: Inglês

10.1067/mai.2000.111235

1097-6825

Catherine Lemière, Simone Chaboilliez, Carole Trudeau, Rame Taha, Karim Maghni, James G. Martin, Qutayba Hamid,

Contact Dermatitis and Allergies

Abstract Background: Little is known about the comparative kinetics of eosinophil recruitment after exposure to low- and high-molecular-weight sensitizers in subjects with occupational asthma (OA). Objectives: The aims of the study were to investigate the kinetics of changes in inflammatory mediators associated with eosinophil infiltration (IL-5 and eotaxin) and to examine the nature of the airway inflammation induced in response to different types of occupational agents. Methods: We investigated 15 subjects with OA caused by high- and low-molecular-weight agents. The subjects were exposed to increasing doses of the relevant occupational agent over 3 to 4 days until a 20% fall in FEV 1 occurred. Methacholine challenge and sputum induction were performed at the end of each day of exposure. Sputum samples were assessed for differential cell counts, including eosinophils, IL-5, and eotaxin messenger RNA. Results: There was an increase in sputum eosinophils, eotaxin, and IL-5 on the day preceding the occurrence of asthmatic reaction, although there was no change in functional parameters (FEV 1 and PC 20 ). Increase in sputum eosinophils was more prominent in subjects exposed to low-molecular-weight agents than to high-molecular-weight agents. Conclusion: Changes in eosinophils, IL-5, and eotaxin precede functional changes after exposure to occupational agents in subjects with OA. Eosinophil inflammation is a feature of exposure to both high- and low-molecular-weight agents. Induced sputum may be a useful tool in the early diagnosis of OA. (J Allergy Clin Immunol 2000;106:1163-70.)