Detection of specific IgE against linear epitopes from Gal d 1 has additional value in diagnosing hen's egg allergy in adults. Issue 12 (24th September 2020)

• Record Type: Journal Article
• Authors: Ehlers, Anna M.; Otten, Henny G.; Wierzba, Eva; Flügge, Ulrike; Le, Thuy‐My; Knulst, André C.; Suer, Waltraud
• Is Part Of: Clinical & experimental allergy. Volume 50:Issue 12(2020)
• Page Start: 1415
• Page End: 1423
• Publication Date: 2020-09-24
• Subjects: food allergy -- hen -- IgE -- linear epitopes's egg; Allergy -- Periodicals; Immunology -- Periodicals; 616.97
• DOI: 10.1111/cea.13730
• Languages: English
• ISSNs: 0954-7894

Abstract

Abstract: Background: Although hen's egg allergy is more prevalent in children, up to 0.6% of adults from different European countries suffer from a persistent or newly onset hen's egg allergy, making accurate diagnosis in adults necessary. However, sensitization to hen's egg extracts, components and linear epitopes is solely studied in children. Methods: Hen's egg allergic (n = 16) and tolerant (n = 19) adults were selected by sensitization towards recombinant components rGal d 1 and/or 3. Sensitization profiles towards egg white and yolk extract and the native components Gal d 1, 2, 3 and 4 were respectively evaluated with the ImmunoCAP or the EUROLINE system. Characterization of linear epitopes was performed with a peptide microarray containing 15mer peptides representing the entire sequence of mature Gal d 1 and 3. Results: Overall, sIgE titres against hen's egg extracts and single components overlapped largely between allergic and tolerant adults. Although the median sIgE/sIgG4 ratio to Gal d 1 was increased in allergic adults, the range was comparable between both groups. Clinically relevant sensitization to Gal d 1 was confirmed by sIgE‐binding to the linear epitopes aa30‐41, aa39‐50 or aa84‐95 in 6/13 allergic adults, mainly suffering from objective symptoms. In comparison, these epitopes were recognized by 1/15 tolerant patient. Only a few linear epitopes were detected for Gal d 3, suggesting a greater importance of conformational epitopes for the recognition of Gal d 3. Conclusion and Clinical Relevance: Specific IgE‐binding to linear epitopes of Gal d 1 is highly specific in identifying hen's egg allergic adults with objective symptoms.