D2.02 - Clinically Relevant Cross-Reactivity Between Artemisia vulgaris and Bee Pollen: A New Paradigm in Postprandial Exercise-Induced Anaphylaxis

Sensitization to pollen from Compositae, particularly Artemisia vulgaris, is well known to generate cross-reactive responses to various plant-derived foods. These reactions are often mild, but severe postprandial anaphylaxis, especially when combined with physical exercise, has been documented. Identifying clinically relevant allergens hidden within complex matrices such as bee-derived products remains a major diagnostic and analytical challenge.

We evaluated a patient with recurrent episodes of exercise-induced anaphylaxis triggered after ingestion of foods including honey, bee pollen, sunflower seeds, curry, and mango. A systematic immunochemical work-up was conducted using SDS-PAGE, IgE-Western blot, and ELISA inhibition assays on protein extracts from Artemisia vulgaris and the implicated foods to characterize IgE-binding patterns and assess cross-reactivity.

Serum IgE from the patient showed strong reactivity to Artemisia vulgaris, with dominant IgE-binding bands at 11, 25, and 31 kDa. Bee pollen exhibited a parallel pattern, with prominent 25–26 kDa bands matching those of Artemisia. Honey displayed only faint reactivity, restricted to high–molecular-weight proteins. Other matrices (curry, mango, sunflower seeds) showed isolated IgE-binding bands without a shared pattern suggestive of cross-reactivity.ELISA inhibition testing demonstrated significant inhibition (>50%) with bee pollen and partial inhibition with honey, confirming the presence of cross-reactive allergens homologous to those of Artemisia vulgaris.

This study provides strong immunochemical evidence that bee pollen can contain allergenic proteins homologous to those of Artemisia vulgaris, acting as hidden triggers of anaphylaxis in sensitized individuals. The absence of cross-reactivity with other foods tested supports the specificity of the Artemisia–bee pollen axis. These findings underscore the need to consider bee-derived products as potential allergenic sources in patients sensitized to Compositae pollen, particularly in the context of exercise-induced anaphylaxis.