Moving from peanut extract to peanut components: towards validation of component‐resolved IgE tests. Issue 6 (29th April 2013)

• Record Type: Journal Article
• Authors: Aalberse, J. A.; Meijer, Y.; Derksen, N.; van der, T.; Knol, E.; Aalberse, R. C.
• Is Part Of: Allergy. Volume 68:Issue 6(2013:Jun.)
• Page Start: 748
• Page End: 756
• Publication Date: 2013-04-29
• Subjects: Allergy -- Periodicals; 616.97
• DOI: 10.1111/all.12160
• Languages: English
• ISSNs: 0105-4538

Abstract

<abstract abstract-type="main" xml:lang="en" id="all12160-abs-0001"> <title>Abstract</title> <sec id="all12160-sec-0001" sec-type="section"> <title>Background</title> <p>Replacement of peanut extracts by recombinant peanut components is an important step in allergy serologic testing. Criteria are needed for the unbiased inclusion of patients into a study to validate such a replacement.</p> </sec> <sec id="all12160-sec-0002" sec-type="section"> <title>Methods</title> <p>Plasma samples from 64 peanut‐positive children (42 reactors, 22 nonreactors in a double‐blind, placebo‐controlled food challenge) were used to compare IgE reactivity to six recombinant peanut allergens with reactivity to natural peanut proteins extracted at neutral or low pH. We tested the hypothesis that poor extractability of Ara h 9 and other basic allergens at neutral pH leads to under‐representation of patients with such sensitization.</p> </sec> <sec id="all12160-sec-0003" sec-type="section"> <title>Results</title> <p>IgE reactivity to the components did not fully explain IgE reactivity to peanut extract in 5 of 32 reactors with IgE to peanut extract ≤100 kU<sub>A</sub>/l. IgE reactivity to components was stronger than to the extract in 11 plasma samples, which was largely due to a low Ara h 8 reactivity of the extract. IgE reactivity to Ara h 9 was much lower than reactivity to other basic proteins, some of which bound IgE well in the RAST, but lost IgE reactivity upon immunoblotting.</p> </sec> <sec id="all12160-sec-0004" sec-type="section"> <title>Conclusions</title> <p>Conventional peanut extracts are deficient in significant IgE‐binding components. The inclusion of patients for a validation study should be based on serology performed with improved peanut reagents to avoid a bias against these under‐represented, potentially important allergens. To judge clinical relevance of an allergen, the reagent used for inclusion of patients needs to be efficient in detecting IgE to this component.</p> </sec> </abstract>