The IgE-facilitated allergen binding (FAB) assay: Validation of a novel flow-cytometric based method for the detection of inhibitory antibody responses Journal Articles uri icon

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  • The IgE-facilitated allergen binding (IgE-FAB) assay represents an in vitro model of facilitated allergen presentation. Allergen-IgE complexes are incubated with an EBV-transformed B cell line and complexes bound to CD23 on the surface of cells are detected by flow cytometry. The addition of serum from patients who have received allergen-specific immunotherapy has been shown previously to inhibit allergen-IgE complex binding to CD23 on B cells. In this study, we describe the characterisation and analytical validation of the grass pollen-specific IgE-FAB assay according to guidelines from the International Conference on Harmonisation. We established the intra- and inter-assay variability of IgE-FAB and have defined the detection limits of this assay. We have also demonstrated assay linearity and robustness. Using the results from a randomised double-blind placebo-controlled trial of grass pollen immunotherapy (n=33), we have defined the clinical sensitivity and specificity of the IgE-FAB assay using ROC curve analysis. In conclusion, the IgE-FAB assay is reproducible, robust, sensitive and a specific method suitable as a tool for monitoring inhibitory antibody function from patients receiving allergen immunotherapy.


  • Shamji, Mohamed H
  • Wilcock, Louisa K
  • Wachholz, Petra A
  • Dearman, Rebecca J
  • Kimber, Ian
  • Wurtzen, Peter A
  • Larche, Mark
  • Durham, Stephen R
  • Francis, James N

publication date

  • December 2006

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