[Efficacy and safety study of standardized mite allergen specific immunotherapy with no reduction during maintenance in children with respiratory allergic disease].

Objective: To explore the optimal regimen of standardized mite allergen immunotherapy for airway allergic diseases in children, and to observe the clinical efficacy, safety and compliance. Method: Use a retrospective real-world study, clinical data from 156 children aged 5-16 years who received subcutaneous immunotherapy (SCIT) with double mite allergen preparation in the pediatrics department of the Third Affiliated Hospital of Sun Yat sen University from June 2019 to September 2020 were selected for allergic rhinitis (AR) and/or allergic asthma (bronchial asthma, BA), including gender, age, total VAS(visual analogue scale) score and CSMS(combined symptom and medication scores) score at different time points (before treatment, 4-6 months, 1 year, and 2 years after initiation of desensitization), peripheral blood eosinophil counts (EOS), serum total IgE (tIgE), specific IgE (tIgE), and serum IgE (tIgE), specific IgE (sIgE), tIgG4, and incidence of local and systemic adverse reactions. All patients had a consistent regimen during the initial treatment phase (dose-escalation phase), which was performed as directed. Among them, 81 cases (observation group) continued to continue subcutaneous injection of 1 ml of vial No. 3 every 4-6 weeks during the dose maintenance phase, while 75 cases (control group) followed the old traditional regimen during the maintenance phase (i.e., change to a new vial to halve the amount of vial No. 3 by 0.5 ml, and then 0.75 ml after 1-2 weeks, and 1 ml in a further interval of 1-2 weeks). The clinical efficacy, safety and adherence to the treatment were compared between the two groups. Results: A total of 81 cases of 156 children were included in the observation group, of which 58 children with AR, 15 children with BA, and 8 children with AR combined with BA; 75 cases were included in the conventional control group, of which 52 children with AR, 16 children with BA, and 7 children with AR combined with BA. In terms of safety, the difference in the incidence of local and systemic adverse reactions between the two groups was not statistically significant ( χ ² =1.541 for local adverse reactions in the control group, χ ² =0.718 for the observation group; χ ² =0.483 for systemic adverse reactions in the control group, χ ² =0.179 for the observation group, P value >0.05 for all of these), and there were no grade Ⅱ or higher systemic adverse reactions in any of them. In the control group, there were 15 cases of dropout at 2 years of follow-up, with a dropout rate of 20.0%; in the observation group, there were 7 cases of dropout at 2 years of follow-up, with a dropout rate of 8.6%, and there was a statistically significant difference in the dropout rates of the patients in the two groups ( χ ² =4.147, P <0.05). Comparison of serological indexes and efficacy (compared with baseline at 3 different time points after treatment, i.e., 4-6 months, 1 year and 2 years after treatment), CSMS scores of the observation group and the conventional control group at 4-6 months, 1 year and 2 years after treatment were significantly decreased compared with the baseline status ( t -values of the conventional group were 13.783, 20.086 and 20.384, respectively, all P -values <0.001, and t -values of the observation group were 15.480, 27.087, 28.938, all P -values <0.001), and VAS scores also decreased significantly from baseline status in both groups at 4-6 months, 1 year, and 2 years of treatment ( t -values of 14.008, 17.963, and 27.512 in the conventional control group, respectively, with all P -values <0.001, and t -values of 9.436, 13.184, and 22.377 in the observation group, respectively; all P -values <0.001). Intergroup comparisons showed no statistically significant differences in CSMS at baseline status, 4-6 months, 1 year and 2 years ( t -values 0.621, 0.473, 1.825, and 0.342, respectively, and P -values 0.536, 0.637, 0.070, and 0.733, respectively), and VAS was no statistically significant difference in comparison between groups at different time points ( t -values of 1.663, 0.095, 0.305, 0.951, P -values of 0.099, 0.925, 0.761, 0.343, respectively); suggesting that the treatment regimens of the observation group and the conventional control group were clinically effective, and that the two regimens were comparable in terms of efficacy. The peripheral blood eosinophil counts of the observation group and the conventional control group decreased significantly from the baseline status at 4-6 months, 1 year and 2 years of treatment ( t -values of the conventional group were 3.453, 5.469, 6.273, P -values <0.05, and the t -values of the observation group were 2.900, 4.575, 5.988, P -values <0.05, respectively). 4-6 months, 1 year and 2 years compared with the baseline status tIgE showed a trend of increasing and then decreasing ( t -value in the conventional group was -5.328, -4.254, -0.690, P -value was 0.000, 0.000, 0.492, respectively, and t -value in the observation group was -6.087, -5.087, -0.324, P -value was 0.000, 0.000, 0.745, respectively). However, the results of intergroup comparisons showed no statistically significant differences in serological indices and efficacy between the two groups in terms of peripheral blood eosinophil counts at baseline status, 4-6 months, 1 year and 2 years ( t -values of 0.723, 1.553, 0.766, and 0.234, respectively; P -values of 0.471, 0.122, 0.445, and 0.815, respectively), tIgE ( t -values of 0.170, -0.166, -0.449, 0.839, P -values 0.865, 0.868, 0.654, 0.403, respectively), tIgG4 ( t -values 1.507, 1.467, -0.337, 0.804, P -values 0.134, 0.145, 0.737, 0.422, respectively). Conclusion: Both immunotherapy regimens for airway allergic diseases with double mite allergen subcutaneous immunotherapy have significant clinical efficacy, low incidence of adverse reactions, and the observation group has better patient compliance than the control group.