D1.285 - Analysis of systemic food reactions in patients sensitized to Bet v1 in Madrid (Spain)

The pathogenesis-related proteins group 10 (PR-10), to which the major birch pollen allergen (Bet v1) belongs, along with profilin, are an increasingly frequent cause of food allergy among Spanish patients. PR-10 proteins and profilin are notably sensitive to heat and digestion and therefore traditionally cause oral allergy syndrome (OAS), but interestingly, increasing number of systemic reactions have been reported in patients sensitized to these proteins. These reactions have been reported mostly following the ingestion of tree nuts, Rosaceae, Apiaceae, and soy milk.

A descriptive study was conducted on a cohort of patients sensitized to Bet v1 and profilin with systemic reactions, evaluated at the Allergy Department of the Hospital Universitario Fundación Jiménez Díaz between January 2020 and July 2024. The analyzed variables included clinical history data (rhinitis, asthma, sensitization to pollens, fruits, nuts and other foods).

Patients were selected based on a history of systemic food reactions and exclusive sensitization to labile plant-food allergens (PR-10 and profilin), resulting in 12 patients. Specifically, 8 patients were monosensitized to Bet v1, while 4 were sensitized to both Bet v1 and profilin. 10 patients experienced systemic reactions manifesting as anaphylaxis and 2 presented with urticaria. 11 had pollen-associated rhinoconjunctivitis (most frequently caused by grass, London plane tree and cupressaceae pollen), whereas only 3 presented with asthma symptoms. The most frequently involved foods in reactions are: Hazelnut, soy products, and melon (3 patients each). Exercise was identified as a cofactor in 4 patients.

This study emphasizes that healthcare providers should be aware that allergies triggered by labile pollen cross-reactive allergens, such as PR-10 and profilin, can also be linked to systemic food reactions. Hazelnut, melon, and soy products were identified as high-risk foods and possible systemic reaction triggers; however, further investigation with a larger cohort of patients is needed.