Allergen-specific IgE measurement with the IMMULITE 2000 system: Intermethod comparison of detection performance for allergen-specific IgE antibodies from Korean allergic patients

Background: Intermethod comparison between IMMULITE 2000 chemiluminescent enzyme immunoassay (CLEIA) and the established CAP test for allergen-specific IgE (sIgE) has only been evaluated by a few studies. Methods: We performed such an interassay comparison using 283 Korean allergic patients with the following: asthma (18.4%), allergic rhinitis (18.4%), both asthma and allergic rhinitis (14.5%), atopic dermatitis (21.9%), and others (26.8%). We compared the sIgE detection performance of both systems for 10 major inhalant allergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, Blattela germanica, cat dander, dog hair, alder, birch, oak, ragweed, and mugwort) and four food allergens (egg white, cow milk, peanut, and shrimp). Results: After 645 paired comparison tests, close association and significant correlation were observed between the results of both assays for most of these allergens (r = 0.525-0.979, p < 0.05, respectively), except for shrimp. Intermethod agreement based on sIgE detection was fair to good (74.1-100%, κ = 0.514-1.000, p < 0.05, respectively) for most allergens except for B. germanica, ragweed, and shrimp. Although both assays showed good accuracy in ROC curve analysis, some minor differences were noted. Conclusions: IMMULITE 2000 CLEIA for sIgE detection showed fair to good intermethod correlation, association, agreement, and accuracy in comparison to the established CAP assay among Korean allergic patients. However, we should take into account the intermethod differences between both assays for clinical applications.