Cor a 14, hazelnut-specific IgE, and SPT as a reliable tool in hazelnut allergy diagnosis in Eastern Mediterranean children

Abstract

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.