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Published on: July 10, 2018
The bronchial response to mannitol is attenuated by a previous methacholine test: but not vice versa
E Gade1, S F Thomsen, C Porsbjerg
1Department of Respiratory Medicine, Copenhagen University Hospital, Bispebjerg Hospital, Copenhagen, Denmark.
Aim:
To examine the airway response to inhaled mannitol performed before or after a methacholine challenge test in a group of asthmatics with different levels of disease.
Methods:
A total of 48 asthmatics, 18-73 years of age, were included in the study. Two pairs of challenges were performed in a random order on two separate days > or =24 h apart: either with mannitol performed first on day one, followed > or =1 h by methacholine, and methacholine as the first on day two, followed > or =1 h by mannitol or vice versa. A questionnaire-based interview was performed and lung function, exhaled nitric oxide, skin prick test, and blood eosinophil count were measured.
Results:
A total of 44% of the asthmatics used inhaled corticosteroids and 48% were atopic. The airway response to mannitol was attenuated when mannitol was given after methacholine, compared with the response to mannitol when it was given first [log response dose ratio (RDR): 1.42 vs. 1.60 (P=0.004)], whereas the response to methacholine was unchanged in the opposite test order [log RDR: 0.81 vs. 0.96 (P=0.102)].
Conclusion:
Bronchial challenges with inhaled mannitol and methacholine may be performed on the same day but provocation with mannitol should be performed before methacholine.
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