IgE-based analysis of sensitization and cross-reactivity to yellow mealworm and edible insect allergens before their widespread dietary introduction.

The European Commission authorized the use of dried yellow mealworm (Tenebrio molitor - TM) as a food ingredient under Regulation EU 2021/882. As TM emerges as an important allergen source, sensitization and allergy to TM in various populations need investigation. The aim of this study was to assess the incidence of sensitization to TM before its introduction as a food ingredient in Poland, as well as checking the occurrence of co-sensitivity to TM and other invertebrate allergenic extracts and molecules. This analysis was performed using serum allergen-specific immunoglobulin E (sIgE) results in 6,173 individuals using the ALEX2 test to detect sensitivity to TM and other related allergens. A total of 4.3% of the study population had sIgE to TM extract, with 0.7% of those individuals being mono-sensitized to TM. Sensitization to TM was most commonly associated with a positive response to house cricket and migratory locust allergens. sIgE antibodies against TM significantly more commonly (p < 0.001) co-occurred with sIgE against other invertebrate allergens. Patients with sIgE against TM were most likely sensitised to tropomyosins (49.1% of patients), Niemann-Pick C2 protein (43.8%), group 5/21 allergen (38.6%), class III chitinases (37.1%), and cysteine proteases (34.1%). Based on the serum asIgE levels to TM prior to this ingredient being introduced as a food in Poland, we hypothesised that this primary sensitization may be associated with invertebrate allergies. Our analysis showed that sensitisation to TM was most commonly associated with a positive reaction to house dust mites and shrimp tropomyosins. Therefore, we speculate that individuals allergic to shrimp should exercise caution when consuming foods containing TM.