Diagnostic Performance of Recombinant Peanut Allergens in Children: sIgE Cut-Offs and Anaphylaxis Risk.

AIM: Component-resolved diagnostics (CRD) improve diagnosis and risk stratification in peanut allergy. We evaluated the diagnostic performance of five recombinant peanut allergens for predicting peanut-induced anaphylaxis. METHODS: We retrospectively analysed 164 children with peanut sensitization and elevated IgE to recombinant allergens. Patients were classified as Group A (no/mild symptoms) or Group B (anaphylaxis). Specific IgE levels were compared, ROC curves identified optimal cut-offs, and odds ratios were estimated using Firth penalized logistic regression. RESULTS: Ara h 1-, Ara h 2- and Ara h 3-specific IgE levels were significantly higher in Group B. The strongest association was observed for Ara h 2 (OR 19.65, 95% CI 5.83-72.56; p < 0.001), followed by Ara h 3 (OR 7.27, 95% CI 2.31-26.34; p = 0.001) and Ara h 1 (OR 6.21, 95% CI 1.77-20.73; p = 0.006). Ara h 8 was not associated with anaphylaxis, whereas Ara h 9 showed an inverse association (OR 0.23, 95% CI 0.06-0.73; p = 0.012). Optimal cut-offs were Ara h 1 ≥ 2.60, Ara h 2 ≥ 10.36 and Ara h 3 ≥ 0.18 kUA/L. CONCLUSIONS: Specific IgE to Ara h 1, Ara h 2 and Ara h 3, particularly Ara h 2, was associated with peanut-induced anaphylaxis. The proposed cut-offs require prospective validation.