Increasing the accuracy of peanut allergy diagnosis using Ara h2

Abstract

<h3>Background</h3> Measurement of whole peanut-specific IgE (sIgE) is often used to confirm sensitisation but does not reliably predict allergy. Ara h2 is the dominant peanut allergen detected in 90–100% of peanut allergies. <h3>Objectives</h3> To determine whether Ara h2 testing might improve the accuracy of diagnosing peanut allergy and therefore circumvent the need for an oral food challenge (OFC). <h3>Methods</h3> Infants from the population-based HealthNuts study were skin-prick tested to determine peanut sensitisation and subsequently underwent a peanut OFC to confirm allergy status. In a stratified random sample of 200 infants (100 peanut allergic and 100 peanut tolerant), whole peanut sIgE and Ara h2 sIgE were quantified by fluorescence enzyme immunoassay. <h3>Results</h3> We report that using a combined approach of plasma sIgE testing for whole peanut sIgE followed by Ara h2 sIgE for the diagnosis of peanut allergy, the number of OFCs required are reduced by almost two-thirds. <h3>Conclusion</h3> Who le peanut IgE followed by Ara h2 sIgE testing should be considered as the preferred two-step diagnostic tool for determining peanut allergy, as we have shown greater diagnostic accuracy than either whole peanut sIgE or peanut SPT alone.