Allergen immunotherapy ; Biomarker ; Immunoglobulin G4 ; Immunoglobulin E
Abstract
Purpose: Biomarkers for the efficacy of allergen immunotherapy (AIT) are still lacking. The aim of this study was to investigate the role of allergen-specific immunoglobulin G4 (sIgG4) as a biomarker of AIT using the Korean AIT registry. Methods: We enrolled 26 allergic rhinitis patients with/without asthma received AIT for house dust mites (HDM) and/or other allergens (cat, dog, and pollen) from the Allergen Immunotherapy Database Establishment in Korea, which is non-interventional, multicenter, prospective observational study. Patient enrollment was carried out between 2018 and 2021. Clinical efficacy was evaluated with rhinitis symptom score, medication score and modified combined symptom and medication score (mCSMS), visual analogue scale (VAS), and quality of life (QoL). Allergen-specific IgE (sIgE), sIgG4, and sIgE/sIgG4 ratios were measured at baseline and after three years of AIT. Changes in immunologic markers and clinical outcomes were analyzed over the study period. Results: Significant improvements were observed from baseline to follow-up in medication score (Delta-0.35 +/- 0.69, P=0.023), mCSMS (Delta-0.47 +/- 1.07, P=0.034), and quality of life (Delta-10.96 +/- 12.1, P<0.001). sIgG4 levels significantly increased for Dermatophagoides pteronyssinus (Delta 2.34 +/- 2.53, P<0.001) and Dermatophagoides farinae (Delta 2.94 +/- 2.15, P<0.001). The sIgE/sIgG4 ratios significantly decreased for D. pteronyssinus (Delta-6.52 +/- 9.91, P=0.004) and D. farinae (Delta-7.25 +/- 14.64, P<0.001). Notably, the change in sIgE/sIgG4 ratio for D. pteronyssinus correlated significantly with changes in VAS scores (r=0.81, P=0.015). Conclusion: The sIgG4 and sIgE/sIgG4 ratio to HDM may be useful biomarkers for the clinical efficacy of SCIT in patients with HDM-sensitized allergic rhinitis. Further studies with a larger population are needed.