D2.178 - Allergen-specific IgE/IgG4 ratio as biomarker of allergen immunotherapy efficacy in house dust mite-sensitized allergic rhinitis

Biomarkers for the efficacy of allergen immunotherapy (AIT) are still lacking. Increases of allergen-specific IgG₄ (sIgG₄) have been demonstrated during AIT, but their role as biomarker has not been fully investigated. The aim of this study was to investigate the role of sIgG₄ as a biomarker of AIT using the Korean AIT registry.

We enrolled 26 patients with allergic rhinitis with/without asthma received AIT for house dust mites (HDM) and/or other allergens (cat, dog, pollen) from the Allergen Immunotherapy Database Establishment in Korea (AIDEsK) which is non-interventional, multicenter, prospective observational study, and patient enrollment was carried out between 2018 and 2021. Clinical efficacy was evaluated with rhinitis symptom score, medication score and combined symptom and medication score (CSMS), VAS, and QoL. We measured allergen-specific IgE (sIgE), sIgG₄, and sIgE/sIgG₄ ratio at baseline and three-year follow-up. We analyzed changes of immunologic makers and clinical efficacy from baseline to three-year follow-up levels.

There were significant changes in rhinitis symptom score (△-1.08±1.15, p=0.001), medication score (△-0.35±0.69, p=0.023), CSMS (△-0.47±1.07, p=0.034), and QoL (△-10.96±12.1, p<0.001) from baseline to three-year follow-up levels. Specific IgG₄ levels showed significant changes from baseline to three-year follow-up levels in Dermatophagoides pteronyssinus (△2.34±2.53, p<0.001) and Dermatophagoides farinae (△2.94±2.15, p<0.001). There were significant changes from baseline to three-year follow-up levels in sIgE/sIgG₄ ratio of Der p (△-6.52±9.91, p=0.004) and Der f (△-7.25±14.64, p<0.001). There were significant correlations between changes of sIgE/sIgG₄ ratio to HDM and changes of CSMS (Der p: r = -0.74, p=0.024; Der f: r = -0.45, p=0.026).

Allergen-specific IgE/IgG₄ ratio to HDM may be a useful biomarker for clinical efficacy for SCIT in patients with HDM-sensitized allergic rhinitis. Further study with larger population are needed.