Background: The mechanisms responsible for the difference between clinically irrelevant IgE-sensitization and allergic rhinitis are not fully understood.
Objective: We evaluated the humoral and cellular mechanisms that may be associated with the presence of allergic rhinitis symptoms.
Methods: We selected 26 subjects with positive grass pollen skin tests and IgE antibodies to Timothy (g6) and the major grass allergens rPhl p 1, 5b. Fourteen of those patients reported a history of allergic rhinitis. During winter, we performed a grass pollen CD63 basophile activation test using four log allergen concentrations, followed by a grass nasal provocation test (NPT). We obtained symptom scores in the subsequent pollination season.
Results: We showed that subjects with a positive NPT have significantly higher CD63 basophile grass pollen responsiveness than NPT-negative subjects, preferably at submaximal allergen concentrations, which represent cellular sensitivity. Moreover, basophile sensitivity positively correlated with the size of the grass-specific IgE fraction in relation to total IgE, and it was highly predictive of allergic rhinitis symptoms in the following pollination season.
Conclusion and clinical relevance: Allergic rhinitis symptoms are significantly associated with allergen-specific basophile sensitivity. In vitro evaluation of basophile sensitivity should prove useful for distinguishing clinical phenotype of allergic sensitization.
© 2011 Blackwell Publishing Ltd.