Cross-reactive carbohydrate determinant interference in cellulose-based IgE allergy tests utilizing recombinant allergen components

Edsel Sinson, Camille Ocampo, Cindy Liao, Steven Nguyen, Lauren Dinh, Kelline Rodems, Eric Whitters, Robert G. Hamilton

Research output: Contribution to journalArticle

Abstract

Background Cross-reactive carbohydrate determinant (CCD) structures found in plant and insect glycoproteins are commonly recognized by IgE antibodies as epitopes that can lead to extensive cross-reactivity and obscure in vitro diagnostic (IVD) serology results. With the introduction of component resolved diagnosis (CRD), recombinant non-glycosylated components have been utilized to mitigate the risk of CCD-specific IgE (sIgE) detection. However, a recent study has shown that CCD-sIgE may bind directly to the cellulose solid phase matrix used in certain in vitro diagnostic assays, eliminating the advantage of CRD over traditional extractbased testing. The aim of this study is to further investigate the prevalence of CCD-sIgE interference on a commonly-used in vitro sIgE automated platform which employs a cellulose- based matrix to immobilize CCD-free recombinant components. Methods Sera from patients sensitized to peanut, silver birch, and/or timothy grass were analyzed for CCD-sIgE reactivity on ImmunoCAP/Phadia and NOVEOS autoanalyzers against the MUXF3 carbohydrate component. Positive CCD-sIgE sera were further analyzed against non-glycosylated recombinant components bound to the ImmunoCAP solid phase in the absence and presence of a soluble CCD inhibitor. For comparison, sera were then analyzed on NOVEOS, a non-cellulose based automated sIgE assay. Results Sera from 35% of the sensitized population tested in this study were positive (≥0.35 kU/L) for CCD-sIgE. Of those positives, 17% resulted in CCD-sIgE-positive (false positive) results on ImmunoCAP using non-glycosylated allergosorbents that were negative on NOVEOS. Sera producing false-positive results on ImmunoCAP had varying levels of CCD-sIgE from 0.67 kU/L to 36.52 kU/L. The incidence of CCD interference was predominantly delimited to low-positive IgE results (0.35 kUA/L- 3.00 kUA/L). Conclusion Falsely elevated diagnostic allergen-sIgE results can commonly occur due to the presence of CCD-sIgE using assays that employ a carbohydrate matrix-based allergosorbent. Even the use of non-glycosylated recombinant allergenic components coupled to cellulose matrices do not reduce their risk of detection. The risk of CCD interference that compromises quantitative IgE results can be mitigated by the addition of a soluble CCD inhibitor to positive CCD-sIgE containing sera or by alternatively using a non-cellulose based sIgE assay, such as the NOVEOS assay.

Original languageEnglish (US)
Article numbere0231344
JournalPloS one
Volume15
Issue number4
DOIs
StatePublished - Apr 2020

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)
  • General

Fingerprint Dive into the research topics of 'Cross-reactive carbohydrate determinant interference in cellulose-based IgE allergy tests utilizing recombinant allergen components'. Together they form a unique fingerprint.

  • Cite this