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

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.