Original Article
Cor a 14, Hazelnut-Specific IgE, and SPT as a Reliable Tool in Hazelnut Allergy Diagnosis in Eastern Mediterranean Children

https://doi.org/10.1016/j.jaip.2015.12.012Get rights and content

Background

Improving the diagnostic efficacy of laboratory tests might reduce the need for oral food challenges and facilitate our daily practice.

Objective

We aimed to determine cutoff values and probability curves, as well as to investigate the role of component-resolved diagnosis in predicting clinical reactivity in children with hazelnut allergy and to evaluate the association with pollen sensitivity.

Methods

A total of 56 children with hazelnut allergy who underwent double-blind placebo-controlled food challenge and 8 children who experienced anaphylaxis after accidental hazelnut intake were included. Serum IgE levels to hazelnut extract, Cor a 1, Cor a 8, Cor a 9, Cor a 14, and Bet v 1 were measured with the ImmunoCAP system. Skin prick tests (SPT) with hazelnut, other implicated foods, and aeroallergens were performed.

Results

The optimal cutoff levels for hazelnut sIgE and SPT wheal diameter that predicted clinical reactivity with the highest sensitivity and specificity were 3.15 kU/L and 7.5 mm, respectively. Among the components, only Cor a 14 discriminated between reactive and nonreactive children. The area under curve (AUC) at the optimal cutoff point of 0.63 kU/L for Cor a 14 (0.936) was higher than the AUC of hazelnut sIgE (0.818) and SPT wheal diameter (0.803). For the first time, a 95% probability for clinical reactivity was estimated for SPT wheal diameter, IgE to hazelnut extract, and to Cor a 14 at 12 mm, 10.2 kU/L, and 1.0 kU/L, respectively.

Conclusion

Cor a 14 was found to be a useful and reliable tool for predicting clinical reactivity in children with hazelnut allergy in the Eastern Mediterranean area.

Section snippets

Study population

Children with IgE-mediated hazelnut allergy being followed up at the Division of Pediatric Allergy in Hacettepe University between January 2011 and January 2014 participated in the study. All parents were questioned diligently to determine reliable cause and effect relationships between the ingestion of hazelnut and the presentation of symptoms. Data collected included age, gender, baseline symptoms, sIgE levels, SPT wheal diameters, other food allergies, and associated atopic diseases.

The

Results

A total of 64 children (70.3% boys) with a median (IQR) age of 3.4 (2.1-7.2) years participated in the study (Table I). There was a male predominance in the children and most of them had atopic dermatitis in their clinical history. DBPCFC tests were performed in 56 children to determine the clinical reactivity to hazelnut. Eight children were included in the study without performing food challenge on account of experiencing anaphylaxis within the last 12 months after accidental hazelnut intake.

Discussion

This study is a comprehensive evaluation of hazelnut allergy combining the previous methods consisting of SPT and sIgE to natural hazelnut extract and the new recombinant and natural hazelnut allergens including Cor a 1, Cor a 8, Cor a 9, and Cor a 14 in hazelnut-reactive versus hazelnut-tolerant and pollen-sensitive versus non–pollen-sensitive subjects. In this study, we determined optimal cutoff values and probability curves of natural hazelnut extract sIgE, SPT wheal diameter, and IgE to Cor

References (26)

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This study was supported by the Scientific Research Unit (SRU) of Hacettepe University, number 012 D11 101 005. SRU had no involvement in the study design, data analysis and interpretation, writing the report, and decision to submit the article for publication.

Conflicts of interest: The authors declare that they have no relevant conflicts.

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