Bronchial provocation test with allergen: comparison between two different techniques.
Allergen bronchial provocation tests (BPTs) are often used for assessment of treatment efficacy. Usually, the allergen dose provoking a 20% fall of forced expiratory volume in one second (FEV1) (PD20) is determined on a prestudy day, and this single dose is administered for comparisons on study days. The inhalation of allergen may cause both an isolated early asthmatic response (EAR) or, more frequently, an EAR followed by a late asthmatic response (LAR). Whether the method used to elicit EAR, i.e. the inhalation of cumulative doses up to PD20 or the inhalation of a single predetermined PD20, give comparable results has not been established. We have, therefore, compared the results obtained using the two methods. Twelve patients underwent a first BPT with the increasing doses method and a second BPT with a single dose method. EAR, LAR, and allergen-induced increase of methacholine (MCh) sensitivity were compared. Both methods gave similar EAR's and LAR's although EAR tended to be more severe with the increasing dose method than with the single dose method. The ratio of postallergen/preallergen MCh sensitivity was poorly reproducible.
Dipartimento di Scienze Motorie, Università di Genova, Italy.
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Crimi
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Balbo
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Lazzarotti
D000328:Adult; D000485:Allergens; D001249:Asthma / Q000175:diagnosis; D001985:Bronchial Provocation Tests / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male
D000485:Allergens