Molecular profiling in bee venom allergy: clinical and therapeutic characterization in a Portuguese cohort.

Background. Bee venom allergy (BVA) can trigger local and systemic allergic reactions, including anaphylaxis. Recently, the molecular sensitization profile has gained importance in the reaction's stratification and venom immunotherapy (VIT). Methods. Retrospective analysis of patients with hypersensitivity to BVA, confirmed by sIgE to Apis mellifera ≥ 0.35 kU/L and/or positive skin tests to bee venom commercial extract, evaluated in specialized consultation. Demographic, clinical, and laboratory data were analyzed, looking for risk factors associated with the severity of the index reaction and reactions during VIT. Results. 93 patients were included (55.9% male; median age of 46 years), 57.3% with atopic comorbidities, and 23.4% with cardiovascular comorbidities. The median specific IgE to Apis mellifera was 6.7 (IQR 1.0-20.3) kU/L. Regarding the molecular profile, the median IgE to Api m 1 was 0.5 kU/L (57.5% positive out of all measurements); Api m 4 - 0.01 kU/L (11.9% positive), and Api m 10 - 0.3 kU/L (50.0% positive). The severity of the index reaction correlated positively with older ages (p = 0.040; r = 0.249), in contrast to monosensitization to Api m 1, which was an independent predictor of milder reactions (p = 0.015). Sensitization to Api m 10 was associated with a higher likelihood of reactions during VIT (p = 0.038) but showed a trend toward fewer systemic reactions at re-stings (p = 0.097). Conclusions. Molecular sensitization profile appears to be relevant not only to the severity of index reactions but also during VIT. Studies of a large cohort of patients with molecular profiles are essential to validate these results and improve the clinical and therapeutic approach to BVA.