Can serum white birch (Betula verrucosa) pollen antigen (Bet v 1) immunoglobulin E measurement distinguish between sensitization and allergy?

BACKGROUND: In clinical practice, it is fundamental to distinguish between sensitization and allergy, mainly with respect to polysensitized patients. The aim of this study was to evaluate whether serum immunoglobulin E (IgE) to white birch (Betula verrucosa) pollen antigen (Bet v 1) assessment might be able to differentiate simple sensitization from true allergy. METHODS: In total, 197 subjects (100 females; mean age 44.9 years) with serum Bet v 1 IgE positivity and history of nasal symptoms were evaluated. Subjects were subdivided in 2 groups: allergic and sensitized. RESULTS: Allergic patients were 58.4% of the total; they had higher serum Bet v 1 IgE levels than sensitized subjects (p < 0.001). A serum IgE to Bet v 1 value >8.94 kilo units of allergen per liter (kUA/L) was able to differentiate between sensitization and allergy (area under the receiver operating characteristic curve [AUC] = 0.76; diagnostic odds ratio, ie, degree of agreement between health status and dichotomized IgE levels [DOR] = 6.5). Gender and season when the blood was drawn influenced IgE levels. CONCLUSION: Serum Bet v 1 IgE measurement may be able to differentiate sensitization from allergy in subjects with sensitization to Betulaceae pollen allergens. Thus, Bet v 1 IgE measurement should be considered a useful step in the management of patients with allergic rhinitis due to Betulaceae pollen allergens.