Lipid transfer protein sensitization: reactivity profiles and clinical risk assessment in an Italian cohort.

Background Nonspecific lipid transfer proteins (ns LTPs) represent a major cause of systemic food allergic reactions in the Mediterranean area. This study investigate hierarchical patterns and cluster relationships of IgE sensitization to different ns LTPs, and the relationship to clinical allergy in a large Italian cohort. Methods A total of 568 ns LTP-positive subjects after IgE Immuno CAP- ISAC microarray analysis with Ara h 9, Art v 3, Cor a 8, Jug r 3, Pla a 3, Pru p 3 and Tri a 14 allergens were studied. IgE inhibition experiments were carried out with mugwort and plane tree pollen extracts. Results Eighty-two per cent of ns LTP-positive participants (94% if <6 years old) were Pru p 3^pos, and 71% were Jug r 3^pos. Participants who reacted to >5 ns LTPs reported a higher incidence of food-induced systemic reactions. Only Art v 3 and Pla a 3 (mugwort and plane tree ns LTPs, respectively) were associated with respiratory symptoms, and a correlation was observed between sensitization to pollen and plant food ns LTPs, particularly between Pla a 3 and tree nut/peanut ns LTPs. Co-sensitization to Par j 2 and PR-10 or profilin pan-allergens was associated with a lower prior prevalence of severe food-induced reactions. In inhibition assays, plane and mugwort pollen extracts inhibited 50-100% of IgE binding to food ns LTPs in microarrays. Conclusions Testing IgE reactivity to a panel of ns LTP allergens unveils important associations between ns LTP sensitization profiles and clinical presentation and allows the identification of novel cluster patterns indicating likely cross-reactivities and highlighting potential allergens for ns LTP immunotherapy. [ABSTRACT FROM AUTHOR]