D2.293 - Differential Clinical Implications of Peach Allergen Components Pru p 3 and Pru p 7

Pru p 3 (lipid transfer protein, LTP) and Pru p 7 (gibberellin-regulated protein, GRP) are recognized as major peach allergen components. While IgE to Pru p 7 has been associated with systemic reactions, the immunological context of these components and their relationships with clinical phenotypes in real-world practice remain incompletely defined.

We retrospectively analyzed 80 patients evaluated for suspected peach-related allergic symptoms at a single center. Based on detailed clinical history and diagnostic evaluation, patients were classified according to the identified causative allergen: peach, other fruits, tree nuts, non-fruit allergens, or not identified. Serum IgE to Pru p 3 and Pru p 7, various pollen-specific IgE, total IgE, and thymus and activation-regulated chemokine (TARC) were measured.

Spearman’s rank correlation was used to assess associations between component-specific IgE and immunological markers in the entire cohort. Clinical phenotype analyses comparing localized and systemic reactions (including anaphylaxis) were restricted to patients with peach- or other fruit-induced reactions and were performed using the Wilcoxon rank-sum test. Exploratory multivariable logistic regression analysis was also conducted.

Identified causative allergens were peach (N=26), other fruits (N=19), tree nuts (N=3), and non-fruit allergens (N=10); in 22 patients, food allergy was not confirmed. Pru p 3–specific IgE showed a strong correlation with total IgE (ρ=0.776) and broad correlations with multiple pollen-specific IgE, consistent with extensive IgE cross-reactivity. In contrast, Pru p 7–specific IgE demonstrated generally weaker correlations with these markers. Neither component showed a significant correlation with TARC.

Among patients with peach- or other fruit-induced reactions, Pru p 7–specific IgE levels were significantly higher in those with systemic reactions, including anaphylaxis, whereas Pru p 3–specific IgE levels did not differ between clinical phenotypes. The association between Pru p 7–specific IgE and systemic reactions remained evident in exploratory multivariable logistic regression analysis after adjustment for age and sex.

Pru p 3 appears to reflect broader atopic sensitization and IgE cross-reactivity, whereas Pru p 7 is more closely linked to systemic clinical phenotypes in peach- and fruit-induced allergic reactions, suggesting its potential role as a qualitative marker of disease severity.