[The development of a highly sensitive IgE immunoradiometric assay using monoclonal antibodies]

We have developed two-site immunoradiometric assay (IRMA) for quantitation of human serum IgE, using two different anti-IgE monoclonal antibodies which recognize different epitopes on IgE molecule. We obtained 25 different monoclonal antibodies classified seven groups, and then two different monoclonal antibodies were selected for bead coater and tracer after checking the titer and specificity of each antibody. IgE IRMA we developed here showed good performance in terms of specificity, sensitivity and reproducibility. No cross-reactivity to IgG, IgM and albumin in the level of normal range was observed. The sensitivity for IgE assay was 0.6 x 10(-3) IU/tube and measurable range was 0.01-20.0 IU/tube (0.5-10(3) IU/ml). Coefficient of variations of Intra assay were 2.2-4.3% and average recovery yield was 92.5-108%. Good correlations with Phadebas IgE PRIST and Pharmacia IgE RIA were obtained i.e., y = 1.12x-0.19 (r = 0.96) and y = 0.97x-5.9 (r = 9.7), respectively. These results indicate that the assay system will contribute much to the routine diagnosis for atopic allergy disease and parasitic infections.