Detection of Wheat Lipid Transfer Protein (Tri a 14) Sensitization: Comparison between Currently Available Diagnostic Tools

Background: Wheat lipid transfer protein (LIP; Tri a 14) and omega 5-gliadin have been described as major allergens in wheat allergy (WA) and relevant in wheat-induced anaphylaxis, frequently associated with cofactors. Objective: The objective of this study was to compare tools currently available in routine diagnosis to detect Tri a 14 sensitization, its clinical relevance, and cosensitization to omega 5-gliadin and other LTPs. Methods: One hundred eighteen adults sensitized to rTri a 14 by ImmunoCAP (R) (cutoff >= 0.1 kU(A)/L) identified among 210 LTP allergic patients were included. We evaluated (1) wheat skin prick test (SPT), (2) specific IgE (sIgE) to wheat, rTri a 14, rTri a 19, peach, apple, walnut, hazelnut, and peanut LTPs using ImmunoCAP (R) and microarray ImmunoCAP (R) SAC (cutoff >= 0.31 SU), and (3) wheat-related symptoms. Results: Wheat SPT and sIgE were positive in 31% and 85% of subjects, respectively. rTri a 14 by microarray was detected in 25%. Eight percent showed cosensitization to omega 5-gliadin. Thirty percent referred symptoms (gastrointestinal [13%], urticaria [11%], and anaphylaxis [8%]). Cofactors (45%) were significantly associated with systemic reactions. Conclusion: WA due to Tri a 14 is frequently related with systemic reactions and because are frequently related to cofactors, the culprit may not be suspected. Together with the poor performance to identify Tri a 14 sensitization of the current routine diagnostic tools based on the analysis of whole wheat extract, such as wheat SPT or sIgE, there is a high risk that WA may be overlooked. Thus, when WA is suspected, sIgE Tri a 14 assessment is recommended, together with wheat and omega 5-gliadin, preferably in the singleplex format, and carefully evaluated considering >= 0.1 kUA/L as a cutoff. (C) 2021 S. Karger AG, Basel