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Medline ® Abstract for Reference 50

of 'Reactive airways dysfunction syndrome and irritant-induced asthma'

Long-term outcomes of acute irritant-induced asthma.
Malo JL, L'archevêque J, Castellanos L, Lavoie K, Ghezzo H, Maghni K
Am J Respir Crit Care Med. 2009;179(10):923. Epub 2009 Feb 20.
RATIONALE: The long-term outcomes of acute irritant-induced asthma (IIA) are mostly unknown.
OBJECTIVES: To study the long-term outcomes of IIA.
METHODS: We reassessed 35 subjects who experienced IIA at a mean interval of 13.6 +/- 5.2 years.
MEASUREMENTS AND MAIN RESULTS: The causal agent was chlorine in 20 cases (57%). At diagnosis, the mean +/- SD FEV(1) was 74.5 +/- 19.5% predicted, and all subjects showed bronchial hyperresponsiveness. At reassessment, all subjects reported respiratory symptoms, and 24 (68%) were on inhaled steroids. There were no significant improvements in FEV(1) and FEV(1)/FVC values. Twenty-three subjects had a methacholine test, and only six subjects had normal levels of responsiveness. Of the remaining 12 subjects, six had improvement in FEV(1) after bronchodilator>or=10%. In samples of induced sputum obtained from 27 subjects, six had eosinophils>or=2%. Levels of inflammatory and remodeling mediators were higher than in controlsubjects but were no different from subjects with occupational asthma due to sensitization. Quality of life score was 4.4 +/- 1.5 on a 0 (worst) to 7 (best) scale. Twelve subjects had an abnormal depression score.
CONCLUSIONS: This study provides the first evidence of significant long-term impact of acute IIA on various outcomes.
Axe de Recherche en SantéRespiratoire, Hôpital du Sacré-Coeur de Montréal, Quebec. malojl@meddir.umontreal.ca