Identification of a relevant allergen in the induction of rhinoconjuntivitis in subjects sensitized to peach pollen

Abstract

RATIONALE: Patients can be allergic to multiple substances due to IgEmediated recognition of similar epitopes on proteins from different sources. We applied cluster-detection techniques to food-allergic patient data to detect groups of cross-reactive allergens. Such groupings will be useful for patient-classification, diagnosis, treatment and discovery. METHODS: Skin prick test (SPT) results were obtained for confirmed food-allergic patients, for allergens common to Mediterranean areas. Patients/allergens with much missing data were excluded. Cluster analysis was performed using R/Cytoscape. Similarity was calculated using binary distance metrics. Patient self-reporting data was also obtained. RESULTS: Following exclusion, 525 participants and 45 agents were analysed. The allergens giving rise to the most positive SPT results were olive pollen, peach, tree-nuts/peanuts, grasses and house-dust mites. Cluster analysis found that similar allergen-sources tended to group together, including fruits, mites, nuts, dander, trees, weeds and grasses. Comparison with self-reported previous reactions showed high overlap, albeit with notable exceptions including lentils and sesame seeds. The choice of distance metric and clustering method influenced cluster-building. CONCLUSIONS: SPT analysis reveals patterns of co-reactivity between allergens. This information can aid diagnosis and suggest which allergensources to avoid. It can also guide studies of panallergens and epitope mapping. However, the choice of metric to calculate similarity is important: given the predominance of negative data, assymetric metrics are advised. Future work will investigate other geographical areas and patient IgE levels.

Pru p 9, a new allergen eliciting respiratory symptoms in subjects sensitized to peach tree pollen

“…The data shown in this study provide important and new information about allergens of PT pollen, with specific focus on a novel allergen, named as Pru p 9 [20,21] by the WHO-IUS PLOS ONE nomenclature committee. It belongs to PR-1a protein family, relevant for the induction of respiratory and ocular symptoms in allergic patients, independently whether they were directly or indirectly exposed [28]. Although it has been shown that PT allergens presented in leaves and branches can induce both upper and lower airway symptoms in exposed workers, the association between symptoms and specific allergens from the pollen was not verified [14,15].…”