Diagnostic accuracy of specific IgE to components in diagnosing peanut allergy: a systematic review

<jats:title>Summary</jats:title><jats:p>The diagnostic accuracy of skin prick test (SPT) and specific IgE (<jats:styled-content style="fixed-case">sIgE</jats:styled-content>) to peanut extract in diagnosing peanut allergy is suboptimal. Recent studies have evaluated <jats:styled-content style="fixed-case">sIgE</jats:styled-content> to peanut components as a possible new diagnostic tool. The aim of our review was to systematically search the literature to assess the diagnostic value of <jats:styled-content style="fixed-case">sIgE</jats:styled-content> to peanut components in diagnosing peanut allergy. A literature search was performed in PubMed, Embase and the Cochrane Library. Results were subsequently screened for in‐ and exclusion criteria. The quality of eligible studies was assessed using a standardized quality assessment tool (<jats:styled-content style="fixed-case">QUADAS</jats:styled-content>‐2). Data on sensitivity, specificity, and positive and negative likelihood ratios were extracted or calculated for a descriptive analysis. Twenty‐two studies were eligible, of which 21 studies in paediatric populations. Most studies reported on <jats:styled-content style="fixed-case">sIgE</jats:styled-content> to peanut extract (15) and <jats:styled-content style="fixed-case">sIgE</jats:styled-content> to Ara h 2 (12), followed by SPT (9) and <jats:styled-content style="fixed-case">sIgE</jats:styled-content> to Ara h 1 (7). All studies were at risk of bias or caused applicability concerns on at least one item of the quality assessment tool. The best combination of diagnostic accuracy measures of all diagnostic tests was found for <jats:styled-content style="fixed-case">sIgE</jats:styled-content> to Ara h 2. This finding was independent of geographical location. Compared to SPT and <jats:styled-content style="fixed-case">sIgE</jats:styled-content> to peanut extract, <jats:styled-content style="fixed-case">sIgE</jats:styled-content> to Ara h 2 was mainly superior in diagnosing peanut allergy in case of a positive test result. Worst diagnostic accuracy measures were found in general for <jats:styled-content style="fixed-case">sIgE</jats:styled-content> to Ara h 8 and <jats:styled-content style="fixed-case">sIgE</jats:styled-content> to Ara h 9. <jats:styled-content style="fixed-case">sIgE</jats:styled-content> to Ara h 2 showed the best diagnostic accuracy of all diagnostic tests to diagnose peanut allergy. Compared to the currently used SPT and <jats:styled-content style="fixed-case">sIgE</jats:styled-content> to peanut extract, <jats:styled-content style="fixed-case">sIgE</jats:styled-content> to Ara h 2 was superior in diagnosing peanut allergy and should therefore replace these tests in daily clinical practice, especially in children.</jats:p>