Accuracy of component‐resolved diagnostics in peanut allergy: Systematic literature review and meta‐analysis

Background Peanut allergy diagnosis relies on clinical reactivity to peanut supported by detection of specific IgE (sIgE) antibodies. Extract‐based sIgE tests have low specificity, so component‐resolved diagnostics may complement whole‐extract testing. Methods We systematically collected peanut allergen component data in seven databases and studied the diagnostic accuracy of peanut storage proteins (Arah1, 2, 3) and cross‐reactive peanut proteins (Arah8 PR‐10 and Arah9 lipid transfer protein) through meta‐analyses. The systematic literature review included studies employing peanut components and oral food challenge (OFC) as reference standard in patients suspected of peanut allergy. Data for component sIgE at pre‐defined detection thresholds were extracted and combined in random‐effects bivariate meta‐analyses. Risk of bias was assessed as recommended by Cochrane, with two additional quality items of importance for this review. Results Nineteen eligible studies presented data suitable for meta‐analysis. In cross‐sectional pediatric studies, the pooled sensitivity of Arah2‐sIgE at 0.35 kU A /L cutoff was 83.3% [95% CI 75.6, 88.9] and specificity in diagnosing objective peanut allergy was 83.6% [95% CI 77.4, 88.4]. Compared with 0.1 and 1.0 kU A /L, this threshold provided the best diagnostic accuracy. At 0.35 kU A /L, Arah1 and Arah3 had comparable specificity (86.0% and 88.0%, respectively) but significantly lower sensitivity compared with Arah2 (37.0% and 39.1%, respectively; P < .05). Conclusion sIgE to Arah2 can enhance the certainty of diagnosis and reduce the number of OFC necessary to rule out clinical peanut allergy in unclear cases.