Evaluation of basophil activation test in suspected food hypersensitivity

BackgroundFood hypersensitivity is characterized by a wide range of symptoms. The relationship between symptoms and food is more frequently suspected than objectively proven. Basophil activation test (BAT) is based on the evaluation of activation markers on blood basophils in vitro stimulated with drugs or allergens. The aim of the study was to evaluate the usefulness of BAT when introduced in the routine work-up of suspected food hypersensitivity. MethodsBAT was requested in subjects with food adverse reactions when a discrepancy existed among history and skin prick test (SPT) and/or specific IgE. Data from 150 subjects were analysed using CD63 as basophil activation marker. Thirty controls were evaluated for cut-offs. Immunoblots was performed with the sera of representative subjects positive for BAT and negative for SPT and sIgE. Results1,024 BAT were carried out, the agreement (positive/positive and negative/negative) was 78.5% for BAT vs. SPT and 78.3% for BAT vs. IgE. Atopic patients, but not atopic controls, more frequently had a positive BAT than non-atopic patients (P<0.0001). Among subjects with positive BAT, those with negative sIgE had lower total IgE, P=0.001. Nearly 23.3% of all subjects had positive BAT (for at least one tested food) and both negative sIgE and SPT. Immunoblots revealed the presence of sIgE for the tested foods in representative patients with positive BAT, negative SPT and sIgE. ConclusionIntroduction of BAT in routine of food hypersensitivity, limited to subjects with a discrepancy between history and traditional tests, might be useful particularly when total IgE are low. (c) 2015 International Clinical Cytometry Society