The diagnostic accuracy of skin prick test (SPT) and specific IgE (sIgE) to peanut extract in diagnosing peanut allergy is suboptimal. Recent studies have evaluated sIgE 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 sIgE 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 (QUADAS-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 sIgE to peanut extract (15) and sIgE to Ara h 2 (12), followed by SPT (9) and sIgE 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 sIgE to Ara h 2. This finding was independent of geographical location. Compared to SPT and sIgE to peanut extract, sIgE 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 sIgE to Ara h 8 and sIgE to Ara h 9. sIgE to Ara h 2 showed the best diagnostic accuracy of all diagnostic tests to diagnose peanut allergy. Compared to the currently used SPT and sIgE to peanut extract, sIgE to Ara h 2 was superior in diagnosing peanut allergy and should therefore replace these tests in daily clinical practice, especially in children.

SummaryBackground: Little is known on the clinical relevance of peanut 2S albumin Ara h 7.

BackgroundThe extent of co-sensitization within and between food protein families in an adult population is largely unknown. This study aimed to identify the most frequently recognized components in the PR-10 and storage protein family, as well as patterns in (co-)sensitization, in a birch-endemic area.MethodsResults of ImmunoCAP ISAC, performed during routine care in Dutch adult outpatients suspected of food allergy, were collected.ResultsA total of 305 patients were selected, aged 16–79 years (median 32 years). Sensitization to one or more PR-10 proteins was most frequent (74% of all subjects), followed by 35% to storage protein and 15% to nsLTPs. Within the PR-10 family, subjects were most often sensitized to Bet v 1 (73% of 305), Cor a 1.04 (72%) and Mal d 1 (68%). Sensitization to PR-10s from soy, celery and kiwi occurred distinctively less often (< 55% of Bet v 1 sensitized subjects) compared to other food PR-10s (all > 70%). Subjects sensitized to these ‘less common PR-10 proteins’ were sensitized to more food and inhalant components on the ISAC, compared to subjects sensitized to ‘common PR-10 proteins’ (median 22 vs 13 out of 112, p < 0.0001). Seven subjects demonstrated sensitization to food PR-10 proteins, without concomitant sensitization to pollen PR-10s. Within the storage proteins, sensitization to multiple peanut allergens was most common (on average 3 out of 4).ConclusionsSensitization to PR-10 food proteins could occur without concomitant sensitization to common PR-10 from pollen in a subset of subjects. Less commonly recognized PR-10 proteins appear to be an indication of polysensitization.Electronic supplementary materialThe online version of this article (10.1186/s13601-017-0177-4) contains supplementary material, which is available to authorized users.