Validation of measurement of horse dust mite-specific IgE antibodies in serum using enzyme-linked immunosorbent assam

Abstract

Background : Measurement of allergen-specific IgE antibodies using enzyme-linked immunosorbent assay(ELISA) has been developed and the results were shown to correlate well with those obtained by radioimmunoassay(RIA). However, consensus on the optimal condition and data expression method for the measurement of allergen-specific IgE using ELISA is still not present. Objective : To define the optimal condition for the measurement of allergen-specific IgE using ELISA and to evaluate the accuracy and reproducibility of the results. Method : We measured the concentrations of house dust mite-specific IgE antibodies in serum samples by ELISA and RIA method (AlaSTAT, DPC, USA) using standardized Dermatophagoides farinae antigen(kindly donated by Allergopharma Joachim Ganzer KG, Reinbek, Germany). Results : Optimal antigen coating amount was 2 ㎍/well and optimal serum dilution was 1:10 for ELISA. The expression of the absolute concentration of house dust mite-specific IgE antibodies within the unknown sample using serial dilutions of samples and standard serum seemed to be more reasonable than the expression of absorbance value at a single serum dilution, because the former method provided better inter-assay variation and correlation with RIA results. The results of specific IgE measurement using ELISA significantly correlated with RIA results(r=0.96, p<0.001, n=26). Conclusion : These findings suggest that the measurement of allergen-specific IgE antibodies using the ELISA method can be accurate and reliable if optimal assay conditions and standardized data expression are applied.