Usefulness of Component-resolved diagnostics (CRD) in predicting hazelnut allergy in Japanese children

Abstract

There have been no report of hazelnut allergy in Japan, while allergy to tree nuts are relatively common. Cor a 9 and Cor a 14 may be responsible for systemic reactions to hazelnut in Europe. We hypothesized that component-resolved diagnostics (CRD) would predict the result of hazelnut oral food challenge (OFC) in Japanese children. We recruited 71 subjects (median age: 7.8 years) who were sensitized to hazelnut and performed a hazelnut OFC at Sagamihara National Hospital from 2007 to 2017. OFCs were performed using roasted hazelnut. The sIgE levels (hazelnut/Cor a 1/Cor a 8/Cor a 9/Cor a 14/ alder pollen) were measured using ImmunoCAP. We investigated the predictive factors of a positive hazelnut OFC. Seven subjects (10%) had a positive OFC, and 3 had systemic reactions. The sIgE to hazelnut/Cor a 1/ Cor a 8/Cor a 9/Cor a 14/ alder pollen were 9.3/13.9/4.63/0.05/0.84 /0.10 (median, UA/ml). Hazelnut sIgE was strongly correlated with both Cor a 1 and alder pollen (r=0.76/ 0.74). The sIgE to Cor a 1/alder pollen in OFC positive subjects were significantly lower than those in OFC negative subjects (1.61 vs.14.8, p=0.028, 0.05 vs. 6.07, p=0.029). The area under the receiver operating characteristics curve for hazelnut/Cor a 1/Cor a 8/Cor a 9/Cor a 14/alder pollen was 0.69/0.75/0.56 /0.59/0.69/0.75 (p=0.09/0.03/0.60/0.41/0.09/0.03). Additional evaluation of sIgE to Cor a 1 or alder pollen seems to improve accuracy in diagnosis of hazelnut allergy in Japanese children sensitized to hazelnut.