sIgE to peanut components does not accurately predict the severity of allergy in subjects suspected of peanut allergy

摘要

BackgroundMany recent studies have shown the superior diagnosticaccuracy of specific IgE (sIgE) to Ara h 2 compared tosIgE to peanut extract in diagnosing peanut allergy. Theaim of this study was to analyze the association betweenseverity and sensitization levels (by SPT, sIgE to peanutextract and peanut components Ara h 1, 2, 3 and 8).MethodsPeanut allergic adults (n=94) and children (n=100) witha suspected peanut allergy were included. sIgE levelswere measured by ImmunoCAP (Uppsala, Sweden). Inall subjects the adapted Mueller score was used withone additional category for no symptoms (0-5): 0; nosymptoms/peanut tolerant, 1; oral allergy symptoms, 2;cutaneous/mucosal symptoms, 3; gastrointestinal symptoms,4; respiratory symptoms, 5; cardiovascular symptoms.A severe reaction was defined as a Mueller scoreof 4 or 5. Univariate and multivariate logistic regressionanalysis was used to calculate odds ratio’s.ResultsChildren had significantly higher Mueller scores thanadults (P=0.003) and were therefore analyzed separately.In children 12 patients had a severe allergy, in adults 15patients. In the pediatric population, none of the predictorswas significantly associated with a severe peanutallergy, since the 95% CI of the OR of all predictorsincluded the value 1. In the adult population, sIgE to Arah 2 (OR 1.03, 95% CI 1.01-1.06) and sIgE to peanutextract (OR 1.02, 95% CI 1.003-1.05) were significantlyassociated with a severe peanut allergy. A multivariablelogistic regression analysis was not possible due to thelow number of severely allergic patients. The AUC valuesof sIgE to Ara h 2 and sIgE to peanut extract in the adultpopulation were 0.81 (95% CI 0.69-0.93) and 0.70 (95%CI 0.54-0.86), respectively (compared to 0.77 (0.64-0.89)and 0.69 (0.53-0.85) in the pediatric population).ConclusionIn children no predictor was significantly associated withseverity of peanut allergy. In adults, specific IgE to Ara h 2was a better predictor for severe peanut allergy than sIgEto peanut extract, but was still suboptimal for this purpose.