D2.342 - Environmental Exposure Predicts Severity of Hymenoptera Venom Anaphylaxis Better Than Classical Biomarkers: Added Value of Component-Resolved Diagnostics

Predictors of severity in Hymenoptera venom anaphylaxis and the clinical relevance of component-resolved diagnostics (CRD) remain incompletely defined, particularly in non-European populations.

We conducted a retrospective cohort study evaluating Hymenoptera venom reactions at a tertiary referral center in Chile. Predictors of severity were analyzed among patients with systemic reactions. Multivariable logistic regression assessed factors associated with Grade 3 anaphylaxis. Extract-based sensitization patterns were compared with CRD findings to evaluate diagnostic reclassification and potential impact on venom immunotherapy (VIT) indication.

A total of 185 patients were included, 141 had systemic reactions. Grade 3 anaphylaxis occurred in 28/141 patients (19.1%). Beekeeping-related environmental exposure was independently associated with severity, whereas baseline tryptase, total IgE, venom-specific IgE levels, and atopic comorbidities were not. Of 141 patients with a systemic reaction, there was no association between the molecular components evaluated and the severity of the reaction. Double positivity to honeybee and wasp IgE was observed in 44/185 patients (23,7%). CRD was performed in 15/44 (34%) of these cases; only 7/15 (46,6%) had molecular evidence of true dual sensitization, while the remainder were compatible with single-venom sensitization or were inconclusive. Among the 185 patients, 20 underwent venom immunotherapy (VIT) for bee or wasp venom.

In this Latin American cohort, environmental exposure was a stronger predictor of anaphylaxis severity than traditional immunologic biomarkers. CRD substantially refined interpretation of extract double positivity and may prevent unnecessary dual venom immunotherapy. Integrating exposure history with molecular diagnostics may improve personalized management of Hymenoptera venom allergy.