Ara h 2 and Ara 6 are the best predictors of severe peanut allergy: a double‐blind placebo‐controlled study. Issue 10 (1st July 2015)

• Record Type: Journal Article
• Authors: Kukkonen, A. K.; Pelkonen, A. S.; Mäkinen‐Kiljunen, S.; Voutilainen, H.; Mäkelä, M. J.
• Is Part Of: Allergy. Volume 70:Issue 10(2015:Oct.)
• Page Start: 1239
• Page End: 1245
• Publication Date: 2015-07-01
• Subjects: Allergy -- Periodicals; 616.97
• DOI: 10.1111/all.12671
• Languages: English
• ISSNs: 0105-4538

Abstract

<abstract abstract-type="main" id="all12671-abs-0001"> <title>Abstract</title> <sec id="all12671-sec-0001" sec-type="section"> <title>Background</title> <p>Component‐resolved diagnostics offers a modern tool in peanut allergy, but studies applying consistently double‐blind placebo‐controlled challenges are lacking. We aimed to optimize diagnostics for moderate‐to‐severe peanut allergy in a birch‐endemic region and to create an oral‐peanut challenge with its allergen activity characterized.</p> </sec> <sec id="all12671-sec-0002" sec-type="section"> <title>Methods</title> <p>We performed double‐blind placebo‐controlled peanut challenges for a referred sample of 6‐ to 18‐year‐olds with peanut sensitization or a high suspicion of peanut allergy, including anaphylaxis. We measured specific IgE (sIgE) to Ara h 1, 2, 3, 6, 8, and 9. Testing of allergen activity of the challenge products was by IgE microarray inhibition.</p> </sec> <sec id="all12671-sec-0003" sec-type="section"> <title>Results</title> <p>Of the 102 patients, 69 were challenge positive: 25 (36%) had severe, 36 (52%) moderate, and 8 (12%) mild symptoms; 38 (37%) received adrenalin. SIgE to Ara h 6 AUC 0.98 (95%CI, 0.96–1.00) was the best marker of moderate‐to‐severe allergy. When sIgE to Ara h 2 and Ara h 6 was measured together, all (100%) severe reactions at low doses were successfully diagnosable. SIgE to Ara h 8 had no diagnostic value, AUC 0.42 (95%CI, 0.30–0.52). Both nonroasted and roasted peanut inhibited 100% of IgE binding to Ara h 1, 2, 3, and 6. Nonroasted peanut inhibited 87% of IgE binding to Ara h 8, roasted inhibited 30%. The products lacked Ara h 9 activity.</p> </sec> <sec id="all12671-sec-0004" sec-type="section"> <title>Conclusion</title> <p>Co‐sensitization to Ara h 2 and Ara h 6 was associated with severe reactions distinguishing severe allergy from mild symptoms. SIgE to Ara h 8 added no diagnostic value. Component‐resolved diagnostics reduce the need for oral challenges in peanut allergy.</p> </sec> </abstract>