Usefulness of Total IgE in Predicting Positive Allergen Specific IgE Tests in Korean Subjects

BACKGROUND: Total IgE levels in allergic patients tend to be higher than those in healthy individuals. We evaluated the usefulness of total IgE levels in predicting positive results of allergen specific IgEs in multiple allergen simultaneous tests. METHODS: A total of 133 patients with allergic symptoms were evaluated. Allergen specific IgEs were detected using 3 different kits: Allergy screen (R-biopharm, Germany), AdvanSure Allergy Screen (LG Life Science, Korea) and Polycheck allergy (Biocheck Co., Germany). Total IgE was measured by turbidoimmunometric assay (LX-2200, Eiken Chemical Co., Japan). The patients were divided into high (≥ 170 IU/mL) and low (<170 IU/mL) groups of total IgE level, and the positive rates and number of positive allergen specific IgEs were evaluated in each group. Positive concordance rates among different kits were also evaluated. RESULTS: High total IgE group showed significantly higher positive rates and number of positive allergen specific IgEs in all of the 3 test kits used compared to low total IgE group. Only two of the allergens, Dermatophagoides farinae and Dermatophagoides pteronyssinus had positive concordance rates of ≥ 50%. Allergen specific IgEs to these two allergens showed good correlation with total IgE (correlation coefficients >0.5). CONCLUSIONS: Total IgE appears to be useful in predicting positive results in allergen specific IgE tests to common allergens. The specific IgEs to D. farinae and D. pteronyssinus showed good correlation with total IgE. However, for other allergens, significant differences were observed among different test kits, and the standardization of allergens in multiple allergen simultaneous tests is needed.