Methods: Patients of allergic rhinitis (n=52) sensitized to dust mite were treated with subcutaneous immunotherapy using standardized D. pteronyssinus (Dp) extract. Patients with allergic rhinitis (n=14) sensitized to dust mites who received medications alone were controls. Specific IgE and IgG4 against Dp, D.farina(Df) and corresponding major allergens of group 1 (Dp1 and Df1) and group 2 (Dp2 and Df2) were measured before AIT, 6 months and 12 months later.
Results: Combined symptom and medication scores significantly decreased in immunotherapy group. Specific IgG4 against Dp1, Df1, Dp2 and Df2 allergens increased significantly during AIT (Dp: 0.3, 0.99, 2.72; Dp1: 0.16, 0.67, 2.04; Dp2: 0.10, 0.49, 1.49; Df: 0.38, 1.04, 2.62; Df1: 0.12, 0.37, 1.01; Df2: 0.1, 0.44, 1.27. before AIT, 6 months and 12months later respectively, mgA/L). Of the correlations between dust mite extract IgG4 and the individual subgroup allergen IgG4, it was shown that there were strong correlations in terms of both concentrations (after 12 months: Dp-Dp1: r=0.99; Dp-Dp2: r=0.93; Df-Df1: r=0.93; Df-Df2: r=0.95) and levels of increase (after 12 months: Dp-Dp1: r=0.69; Dp-Dp2: r=0.59; Df-Df1: r=0.90; Df-Df2: r=0.77) (P<0.0001 for all). With the same testing instrument (UniCAP system), Df1 and Df2 IgG4 contributed 87% to Df specific IgG4 response, whereas Dp1 and Dp2 contributed 130% to Dp IgG4 response at the 12 months of AIT.
Conclusions: Our findings underscores the importance of major allergens in AIT standardization and design.