Premium
Validated safety predictions of airway responses to house dust mite in asthma
Author(s) -
Ravensberg A. J.,
Van Rensen E. L. J.,
Grootendorst D. C.,
De Kluijver J.,
Diamant Z.,
Ricciardolo F. L. M.,
Sterk P. J.
Publication year - 2007
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 - 10.1111/j.1365-2222.2006.02617.x
Subject(s) - allergen , methacholine , medicine , histamine , asthma , aeroallergen , house dust mite , inhalation , immunology , sensitization , allergy , provocation test , anesthesia , lung , respiratory disease , pathology , alternative medicine
Summary Background House dust mite (HDM) is the most common aeroallergen causing sensitization in many Western countries and is often used in allergen inhalation challenges. The concentration of inhaled allergen causing an early asthmatic reaction [provocative concentration of inhaled allergen causing a 20% fall of forced expiratory volume in 1 s (FEV 1 )(PC 20 allergen)] needs to be predicted for safety reasons to estimate accurately the severity of allergen‐induced airway responsiveness. This can be accomplished by using the degree of non‐specific airway responsiveness and skin sensitivity to allergen. Objective We derived prediction equations for HDM challenges using PC 20 histamine or PC 20 methacholine and skin sensitivity data obtained from patients with mild to moderate persistent asthma and validated these equations in an independent asthma population. Methods PC 20 histamine or PC 20 methacholine, skin sensitivity, and PC 20 allergen were collected retrospectively from 159 asthmatic patients participating in allergen challenge trials. Both the histamine and methacholine groups ( n =75 and n =84, respectively), were divided randomly into a reference group to derive new equations to predict PC 20 allergen, and a validation group to test the new equations. Results Multiple linear regression analysis revealed that PC 20 allergen could be predicted either from PC 20 methacholine only ( 10 log PC 20 allergen=−0.902+0.741· 10 log PC 20 methacholine) or from PC 20 histamine and skin sensitivity (SS) ( 10 log PC 20 allergen=−0.494+0.231· 10 log SS+0.546· 10 log PC 20 histamine). In the validation study, these new equations accurately predicted PC 20 allergen following inhalation of HDM allergen allowing a safe starting concentration of allergen of three doubling concentrations below predicted PC 20 allergen in all cases. Conclusion The early asthmatic response to inhaled HDM extract is predominantly determined by non‐specific airway responsiveness to methacholine or histamine, whereas the influence of the cutaneous sensitivity to HDM appears to be rather limited. Our new equations accurately predict PC 20 allergen and hence are suitable for implementation in HDM inhalation studies.