Performance of the multiplex and singleplex platforms in allergic phenotype profiling for precision medicine

INTRODUCTION: Multiplex arrays represent an added value in the diagnostic workup for allergy; as a consequence, the comprehension of the performance of these tests is mandatory for allergy specialists. Multiplex specific IgE (sIgE) testing enables determination of sIgE antibodies against multiple recombinants or purified natural allergen components. The aim of this paper is twofold: to report allergic patient phenotype profiling performance of two multiplex tests, comparing the qualitative concordance/discordance of components shared by both platforms and to compare the performance of the multiplex and singleplex platforms in a subgroup of patients with suspected milk and egg allergies.METHODS: Serum samples of 155 patients were studied utilizing Allergy Explorer ALEX2 and ImmunoCAP ISAC tests. Cohen’s Kappa coefficient (k) was assessed for the molecules available in both tests (N.=102).RESULTS: A substantial agreement (k=0.78) was observed between the two methods with 98.4% concordant results when results were dichotomized as negative or positive, but when double-negative results were discarded, the agreement dropped to 70.6%. A subgroup of patients with suspected egg and milk allergies was selected for additional testing with a singleplex platform. Singleplex confirmed positivity in almost all patients with suspected egg (96.2%) and milk (100.0%) allergies. The concordance between the 3 platforms ranged from no to fair (κ: 0.05-0.22).DISCUSSION: The study confirms an overall substantial correlation between ISAC and ALEX2 multiplex platforms in the detection of sIgE for shared molecular components. The ISAC platform is more robust for lipid transfer proteins, profilin and PR-10 (pathogenesis-related) proteins. However, as there is a clinical need for a larger number of molecular allergens to ensure accurate diagnoses, ALEX2 may prove to be an advantageous additional tool in the laboratory, offering more personalized analyses. Additionally, the study reports that both multiplex platforms are considerably less sensitive to egg and milk protein allergens compared to singleplex.