Basophil allergen threshold sensitivity: a useful approach to anti‐IgE treatment efficacy evaluation

Background: Monitoring of the allergen sensitivity of a patient is most important for optimal patient care and a basic prerequisite for immunomodulating treatment. The objective of this study was to investigate how basophil allergen sensitivity can be applied in the monitoring of anti‐immunoglobulin E (IgE) treatment. Methods: Basophils from timothy grass pollen allergic patients were, by flow cytometry, analysed for allergen threshold sensitivity (CD‐sens) by measuring CD63 up‐regulation on CD203c‐identified basophils. The results were compared with maximal percentage CD63 up‐regulation at one allergen dose (CD‐max), skin prick test end‐point allergen titration, (SPT‐sens), nasal provocation titration tests (nasal provocation titre) and serum IgE and IgE antibody concentrations. Results: There was a significant correlation (r = 0.50, P = 0.01) between CD‐sens and SPT‐sens, CD‐sens and the IgE antibody concentration in percentage of ‘total IgE’ (relative IgE antibody concentration) (r = 0.72, P