Murray, L.Van Heerden, C.Ranchod, H.De Beer, C.Van den Berg, SharonTeixeira, M.J.Swanepoel, P.Van Rooyen, CathyVan Niekerk, A.2025-08-072025-08-072024-12Murray, L., Van Heerden, C., Ranchod, H. et al. 2024, 'Comparison of specific IgE against allergen components measured on the ALEX2® Allergy Xplorer and the ImmunoCAP™ ISAC multiplex assays', South African Journal of Child Health, vol. 18, no. 4, pp. 177-182. https://doi.org/10.7196/SAJCH.2024.v18i4.2234.1994-3032 (print)1999-7671 (online)10.7196/SAJCH.2024.v18i4.2234http://hdl.handle.net/2263/103828DATA AVAILABILITY : The datasets generated and analysed during the current study are available from the corresponding author upon reasonable request.BACKGROUND : Allergic disease, mediated by immunoglobulin E (IgE), is common worldwide and its incidence is on the rise. OBJECTIVES : To compare common food, inhalant and cross-reactive molecular components detected by the ImmunoCAP Immuno Solid-phase Allergen Chip (ISAC™) and the Allergy Xplorer (ALEX2®) multiplex IgE assays. METHODS : The study analysed serum samples from 100 patients with suspected allergies. Allergen-specific IgE (sIgE) molecular component measurements were performed using the ImmunoCAP™ ISAC E112i assay (ISAC™) (Thermo Fisher Scientific, Sweden). Subsequently, sIgE molecular component measurements were performed using the Allergy Xplorer 2® (ALEX2®) (Macro Array Diagnostics, Austria). The ISAC™ method tests 112 molecular allergen components. The ALEX2® method offers 295 reportable molecular allergen components and whole allergen extracts. RESULTS : The overall Kappa analysis showed very good agreement in 58.33% (n=28/48) of components, good agreement in 33.33% (n=16/48) of components, moderate agreement in 8.33% (n=4/48) of components and no fair or poor agreements seen among the analysed components. The four components with a moderate agreement were Gly m 4 (PR-10, soy), Ara h 8 (PR-10, peanut), Gly m 5 (storage protein, soy) and Tri aA/TI (alpha amylase/TI, wheat), with K values of 0.52, 0.51, 0.48 and 0.44, respectively. Tri-AA/TI exhibited the lowest agreement. CONCLUSIONS : The study findings demonstrated a good correlation between the ALEX2® and ISAC™ assays for the detection of sIgE against molecular allergen components. ALEX2® offers the benefit of testing 295 molecular allergen components and extracts, as well as cross-reactive carbohydrate determinants (CCD) inhibition.en© This open-access article is distributed under Creative Commons licence CC-BY-NC 4.0.Allergic diseaseAllergy IgE testingMolecular allergy testingImmunoglobulin E (IgE)Article