Improving In Vitro Detection of Sensitization to Lipid Transfer Proteins: A New Molecular Multiplex IgE Assay

Abstract

Scope: LTP-syndrome is characterized by sensitization (IgE) to multiple non-specific lipid transfer proteins (nsLTPs) with a variable clinical outcome. The treatment is primarily based on offending food avoidance. However, the determination of Pru p 3-specific IgE is currently the main diagnostic tool to assess sensitization to nsLTPs. Herein, the study evaluates improvement of LTP-syndrome diagnosis and clinical management using a new IgE multiplex-immunoblot assay with a high diversity of food nsLTPs. Methods and results: An EUROLINE-LTP strip with 28 recombinant nsLTPs from 18 allergenic sources is designed. In total the study investigates 38 patients with LTP-syndrome and compares results from the nsLTPs (LTP-strip) with the respective food extracts of Prick-by-prick (PbP) testing. The agreement exceeds 70% for most nsLTPs, e.g., Pru p 3 (100%), Mal d 3 (97%), Pru av 3 (89%), Pha v 3 isoforms (87%/84%), Ara h 9 (82%), Cor a 8 (82%), and Jug r 3 (82%). The functionality and allergenic relevance of nine recombinant nsLTPs are proven by Basophil activation testing (BAT). Conclusions: The new IgE multiplex-immunoblot nsLTP assay shows a good diagnostic performance allowing culprit food assessment. Negative results from LTP-strip may indicate potentially tolerable foods, improving diet intervention and patients' quality of life.

Update on In Vitro Diagnostic Tools and Treatments for Food Allergies

“…It was observed that there was a positive correlation between the sIgE levels of the single allergen components (Pru p 3, Mal d 3, Ara h 9, Cor a 8 and Jug r 3) with respect to the sIgE levels of the ImmunoCAP. This new IgE multiplex-immunoblot LTP assay showed a good diagnostic performance allowing the culprit food allergies assessment [38]. Another study evaluated the ImmunoCAP and the EUROLINE system for the sensitization profiles towards egg white, yolk extract with the allergen components Gal d 1, 2, 3, 4.…”

“…Milk [56] High throughput Need to improve the Sesame [32] Hazelnut [33] Peanut allergic children [35] Kiwi [36] LTP (Multiple Food) [38] Egg white and yolk [39] Standardized High throughput Can be automatized Poor in detection of sensitization from clinically reactive FA.…”