Relationship between cutaneous allergen response and airway allergen-induced eosinophilia.
BACKGROUND
Determinants of changes in airway caliber after allergen challenge include nonallergic airway responsiveness, immune response and dose of allergen given. However, determinants of the airway inflammatory response to allergens remain to be determined.


OBJECTIVE
To assess the relationship between skin reactivity to airborne allergens and lower airway eosinophilic response to allergen exposure in asthma and allergic rhinitis.


METHODS
Forty-two subjects with mild allergic asthma (mean age 24 years) and 14 nonasthmatic subjects with allergic rhinitis (mean age 25 years) had allergen skin prick tests and titration with the allergen chosen for subsequent challenge. On a second visit, 31 asthmatic subjects had a conventional challenge while 11 asthmatic subjects and all rhinitic subjects had a low-dose allergen challenge over four subsequent days. Induced sputum samples were obtained at 6 and 24 h after the conventional challenge and at days 2 and 4 of the low-dose challenge.


RESULTS
In the asthmatic group, there was a weak correlation between wheal diameter induced by the concentration used for challenge and increase in eosinophils 6 h postconventional challenge (r = 0.372, P = 0.05), but no correlation was observed following the low-dose challenge. Rhinitic subjects showed a correlation between wheal diameter with the allergen dose used for bronchoprovocation and increase in eosinophils at day 2 of low dose (r = 0.608, P = 0.02).


CONCLUSIONS
This study suggests that immediate immune responsiveness to allergen, assessed by the magnitude of the skin response, is a significant determinant of allergen-induced airway eosinophilia and can help to predict the airway inflammatory response.
Boulay
M-E
ME
Centre de Recherche, Hôpital Laval, Institut universitaire de cardiologie et de pneumologie de l'Université Laval, 2725 chemin Sainte-Foy, Québec City, Québec, Canada G1V 4G5.
Lemieux
M-C
MC
Deschesnes
F
F
Boulet
L-P
LP
D000328:Adult; D000485:Allergens / Q000276:immunology*; D001249:Asthma / Q000209:etiology / Q000276:immunology*; D001985:Bronchial Provocation Tests; D004802:Eosinophilia / Q000209:etiology* / Q000473:pathology; D006801:Humans; D006967:Hypersensitivity / Q000150:complications*; D006969:Hypersensitivity, Immediate / Q000175:diagnosis / Q000276:immunology; D012220:Rhinitis / Q000209:etiology / Q000276:immunology*; D012867:Skin / Q000276:immunology*; D012882:Skin Tests; D013183:Sputum / Q000166:cytology
D000485:Allergens