A Comparison of asIgE Levels Measured with ALEX and ImmunoCAP ISAC in Polish Children with Food Allergies

In order to establish the reliability of new multiplex tests for determining allergen-specific immunoglobulin E (asIgE) levels in serum, the results of asIgE determinations obtained via ALEX tests were compared to those obtained via ImmunoCAP ISAC in a group of 40 Polish children hospitalized due to food allergy and/or anaphylaxis. The analysis was based on 6320 determinations of asIgEs relative to 79 common allergen molecules included in both tests (80 tests conducted-40 ALEX and 40 ISAC). The study showed a high correlation of results between the compared diagnostic tests, with the concordance of asIgE determinations at the level of 92.5% (<i>n</i> = 2922). The results of this study showed the sensitivity of the ALEX test to be comparable with that of the ImmunoCAP ISAC test. One indisputable advantage of the ALEX test is its high number of determinations per procedure, which provides more information about the patient's molecular profile; moreover, the use of an inhibitor of the asIgEs that bind to cross-reactive carbohydrate determinants (CCDs) reduces their impact on the results for allergens naturally containing carbohydrate determinants. Comparative analyses of asIgE test results obtained with ALEX and ImmunoCAP ISAC tests demonstrate that the ALEX test is a reliable diagnostic tool for asIgE assessments. However, significant differences in the absolute values of asIgEs relative to individual molecules suggest the need for caution when directly comparing asIgE levels from both tests.