The PORTIA ™ Allergy-Q Enzyme Immunoassay (EIA) is a newly developed screening assay for multiple allergen-specific immunoglobulin E (IgE). The ImmunoCAP Fluorescent EIA System (FEIA) is the most widely used method for the detection of sIgE. In this study, we evaluated the performance of the Allergy-Q system compared to the ImmunoCAP system.
We compared the 2 systems using sera from 260 Korean allergy patients suffering from asthma (26.5%), allergic rhinitis (42.3%), atopic dermatitis (67.7%) and food allergy (18.1%). We compared the sIgE measurement results for 7 inhalant allergens, 5 food allergens, and 4 microorganism allergens.
In total, 1,799 matched test results were analyzed. Except for mugwort and Alternaria, most allergen-sIgE results showed intraclass correlation coefficients of> 0.5. The class associations between trials were reliable for most allergens (gamma = 0.858-0.987, P <0.001). Passing-Bablok regression analysis showed multiple differences in intercept and slope. Agreement between methods was moderate to substantial for most allergens (κ = 0.713-0.898, P <0.001).
The PORTIA ™ Allergy-Q EIA system showed good detection performance compared to the ImmunoCAP FEIA system in Korean allergic patients. However, due to the methodological differences between the 2 trials, careful clinical involvement is required for the interpretation of the Allergy-Q EIA results.
Allergen; Allergy-Q; ImmunoCAP; allergic disease; detection performance; Specific IgE.