Autologous enzyme-linked immunosorbent facilitated antigen binding detects IgE-blocking activity based on direct competition between allergen-specific IgE and non-IgE

Lay abstract Allergy is a serious health problem worldwide. Allergen immunotherapy is a controlled exposure to allergen with the aim of modulating the immune response and reducing symptoms. The immune modulation includes a shift from the production of allergy-inducing IgE antibodies to inhibiting IgG antibodies and the competition between these antibodies for allergen binding when exposed to allergen may be central to the effect of the treatment. The current study addressed several ways of monitoring the changes in IgE and IgG antibodies during house dust mite immunotherapy. A novel assay for monitoring the competitive binding of these antibodies to house dust mite allergen is introduced; it may be used to monitor the immunological changes induced by immunotherapy and help increase treatment compliance. Aim: To measure IgE-blocking activity induced by allergen immunotherapy (AIT) by an enzyme-linked immunosorbent facilitated antigen binding (ELIFAB) assay based on autologous immunoglobulin competition. Methods: The developed ELIFAB assay was used to investigate the kinetics of IgE-blocking activity in 87 patients at multiple AIT treatment time points, in comparison to the changes in IgG(4). Results: High ELIFAB response was observed until 2.5 months of AIT, then significantly decreased after 4 months and remained suppressed during the 3-year AIT period. After treatment cessation, the ELIFAB response was maintained at the level seen at the 4-6 month treatment time point, similar to IgG(4), indicating sustained IgE-blocking activity related to IgG(4). Conclusion: This ELIFAB assay measures the IgE-blocking activity for autologous allergen-specific IgE and non-IgE during and after immunotherapy. It is suited for measuring the sustained IgE-blocking activity induced by AIT.

Automated summary

This study introduced a novel ELIFAB assay for monitoring IgE-blocking activity induced by allergen immunotherapy, which can help understand the long-term effects of immunotherapy.