Pru p 7 Predicts Severe Reactions after Ingestion of Peach in Japanese Children and Adolescents

Introduction: Component-resolved diagnostics is used to diagnose food allergies. However, few reports have evaluated the severity of peach fruit allergy using peach allergen components, including Pru p 7. Objective: This study aimed to predict peach fruit allergy severity based on the presence of specific IgE (sIgE) antibodies (Abs) to peach allergenic components. Methods: Twenty-seven patients with peach fruit allergy were enrolled and classified into two groups: the local reaction (LR) group, including 12 patients with only oral or throat mucosal symptoms, and the systemic reaction (SR) group, including 15 patients, 10 of whom experienced anaphylaxis. Serum sIgE Abs against crude peach extract – Pru p 1, 2, 3, 4, and 7 – and tree pollen were measured. Results: sIgE Ab titers of Pru p 1 and 4 and alder pollen in the LR group were significantly higher than those in the SR group. sIgE against Pru p 7 was significantly higher in the SR group than in the LR group. The frequencies of sIgE Abs against Pru p 1, 4, and 7 in the LR group were 91.7, 66.7, and 16.7%, respectively, while in the SR group these were 80, 20, and 60%. Sensitization to Pru p 2 and 3 was detected but limited in all patients. Conclusions: These findings suggest that sensitization to Pru p 1 and Pru p 4 is associated with local symptoms, and sensitization to Pru p 7 is associated with SR and anaphylaxis. To predict the severity of peach fruit allergy, it is useful to assess sIgE Ab reactions combining Pru p 1, 4, and 7.