Importance of Ara h 6 in peanut allergy diagnosis

Results Twenty-two children (median age: 6.63 y.o.; IQR: 5.22-10.12) were classified as allergic in the basis of at least two convincing clinical reactions upon ingestion of PNT in the last two years. Sixty-nine children (median age: 8.01 y.o.; IQR: 6.01-11.27) were classified as tolerant on the basis of regular consumption of PNT. Positive SPT with commercial PNT extract was found in 86% of the allergic vs. 12% in the tolerant group (p=.000), sIgE for PNT extract was positive (>0.35 kU/L) in 100% of allergic (median: 10.40, IQR: 4.86-70.73) vs. 57% of tolerants (median: 1.69, IQR: 0.85-5.59) (p=.000). In MA-ISAC Ara h 6 was the allergen most frequently recognized (77%) (median: 8,50, IQR:4.29-33.70), followed by Ara h 2 (59%) (median: 17,30, IQR: 0.57-37.41). ROC curves showed the best diagnostic performance for Ara h 6 (AUC=0.852) followed by Ara h 2 (AUC=0.792). A cut-off point of Ara h 6 for maximal sensitivity (Se) and specificity (Sp) was set at 1.245 ISU (Se=0,727 and Sp= 0.971). Conclusions Although Ara h 2 has been regarded as the marker of clinical reactivity in children allergic to peanut, special attention has to be paid to Ara h 6, which has been shown to have better diagnostic performance.