- D1.527 - Low tryptase and combined IgE biomarkers have limited predictive value in children with severe honeybee venom anaphylaxis

Anaphylaxis induced by honeybee venom (HBvA) constitutes a potentially life-threatening condition. The predictive value of baseline serum tryptase (bsT) and combined IgE-based biomarkers in assessing reaction severity remains insufficiently established.

We conducted a retrospective analysis of 43 pediatric patients with a documented history of HBvA who were qualified for venom immunotherapy (VIT) due to the severity of prior reactions. Collected data included Mueller’s severity grade, bsT concentration, total IgE (tIgE), specific IgE (sIgE) to whole bee venom extract, and component-resolved diagnostics (Api m 1, Api m 3, Api m 10). Two derived indices were calculated: Ratio 1 (sIgE to whole extract/tIgE) and Ratio 2 (sIgE to allergen components/sIgE to whole extract). Non-parametric tests and Spearman’s rank correlation coefficient were applied.

Nearly 80% of patients experienced moderate-to-severe anaphylaxis (Mueller grade III–IV). Reaction severity was not associated with bsT, tIgE, venom-specific IgE, molecular sensitization profiles, or the calculated ratios. Severe reactions frequently occurred despite low bsT levels; all 10 children with grade IV anaphylaxis had bsT concentrations <8 µg/L. No significant correlations were observed between bsT and venom-specific IgE or either ratio.

In this sample of paediatric patients with HBvA undergoing VIT, neither bsT nor component-resolved IgE profiles, including derived ratios, were associated with anaphylaxis severity. Severe reactions may occur despite low bsT and heterogeneous molecular sensitization patterns. These findings suggest that laboratory parameters alone are insufficient for risk stratification and support a multifactorial approach to severity assessment in HBvA.