Evaluation of a new multiplex assay for allergy diagnosis

Background: Molecular allergy has significantly improved the quality of allergy diagnosis; however, the positioning of singleplex and multiplex assays in the diagnostic algorithm is still a matter of debate.

Methods: Aim of the study was to test the analytical performance of the recently commercialized Allergy Explorer-ALEX® in a selected population (105 allergic patients and 15 negative controls), comparing it with the reference ImmunoCAP® method and with skin prick test (SPT).

Results: Inter-assay qualitative comparison showed a substantial agreement between ALEX® and SPT (k = 0.64). A substantial agreement between ALEX® and ImmunoCAP® was shown on the detection of IgE to extracts (k = 0.64 for inhalants and k = 0.51 for food allergens), whereas a higher agreement was shown on detection of molecular components (k = 0.92 for inhalants and k = 0.72 for food allergens). Quantitative comparison showed a poor correlation between ALEX® and ImmunoCAP®.

Conclusion: The simultaneous detection of both extracts and molecular components with ALEX® assay can potentially overcome some of the major limitations of the multiplex assay currently in use. However, before using ALEX® as routine method, the analytical performance (in particular for extracts) needs to be further investigated on a larger scale.