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Bronchial responsiveness to adenosine‐5′‐monophosphate and methacholine as predictors for nasal symptoms due to newly introduced allergens. A follow‐up study among laboratory animal workers and bakery apprentices
Author(s) -
De Meer G.,
Postma D. S.,
Heederik D.
Publication year - 2003
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1046/j.1365-2222.2003.01677.x
Subject(s) - medicine , methacholine , asthma , bronchial hyperresponsiveness , eosinophil , allergen , relative risk , confidence interval , adenosine monophosphate , immunology , allergy , respiratory disease , adenosine , lung
Summary Background In asthma patients, bronchial hyper‐responsiveness (BHR) to adenosine‐5′‐monophosphate (AMP) reflects bronchial inflammation more closely than BHR to methacholine. In this follow‐up study we studied bronchial responsiveness to both stimuli as predictors of new‐onset airway symptoms. Methods We included 118 laboratory animal workers and bakery apprentices with a work experience of maximally 1 year. The baseline survey comprised a questionnaire, skin prick tests (SPTs) to common and work allergens, blood eosinophil counting, and bronchial challenge with methacholine and AMP. At follow‐up, questionnaire and SPTs to work allergens were repeated. Airway symptoms to common allergens and work allergens were defined as nasal symptoms, chest tightness or asthma attack during or after contact with either common or work allergen. Bronchial challenge tests were analysed by BHR at a 15% fall in forced expiratory volume of 1 s (FEV 1 ), and by dose–response‐slope (DRS). Results Fourteen subjects (12%) developed airway symptoms to work allergens, of whom 12 had nasal symptoms. A positive SPT to work allergens occurred in 64%, and was the strongest predictor of airway symptoms [relative risk (RR) 7.5, 95% confidence interval (CI) 2.0–28.6]. Other predictors were airway symptoms to common allergens (RR 4.3, 95% CI 1.4–12.8), blood hypereosinophilia (RR 4.4, 95% CI 1.2–15.4) and BHR, with a slightly higher risk estimate for AMP than for methacholine (RR AMP 3.7, 95% CI 1.1–12.5 and RR meth 2.8, 95% CI 1.0–8.5). The difference was more distinct analysing airway responsiveness by DRS, for which AMP predicted symptoms better than methacholine ( P < 0.05). Conclusions Pre‐existent bronchial inflammation or a preinflammatory state marked by AMP (hyper)responsiveness increases the vulnerability to develop nasal symptoms.