[THE SERUM LEVELS OF MILK AND PEANUT-SPECIFIC IGE: ROLE IN THE EVALUATION OF THE RISK FOR ALLERGIC REACTION IN...

The performance characteristics of the ImmunoCAP assay for detecting specific IgE antibodies in the evaluation of milk and peanut allergy have been established. However, the results are not comparable to the IMMULITE 2000, another FDA-approved assay available in Israel, owing to differences in the extracts used, technical method, and population studied.

To establish the performance characteristics and predictive values for the IMMULITE 2000 assay in Israel.

The database of the Allergy Clinic at Schneider Children's Medical Center in Israel was searched for all patients referred for evaluation of allergies in 2006-2009. The results of the milk- and peanut-specific IgE antibody tests were collected and correlated with the clinical diagnoses of milk and peanut allergy or tolerance. Sensitivity, specificity and positive and negative predictive values were calculated as well as receiver operating characteristic (ROC) plots.

The prevalence of milk allergy was 30% (111/369 patients), and peanut allergy, 6% (31/505 patients). The area under the ROC curve was 0.954 for milk allergy and 0.956 for peanut allergy. The levels with a positive predictive value of ≥95% were 10 kU/L and 3 kU/L, respectively. The level of peanut-specific IgE antibodies with a ≥95% positive predictive value was lower than found for the ImmunoCAP in the USA and Europe.

These findings indicate that the decision points used for predicting the risk of future allergic reactions must be calculated separately for different assay methods and different populations. Our findings may assist the allergists in Israel to decide whether to perform a supervised oral challenge in order to verify if the patient has developed tolerance to milk or peanuts.