Efficacy of House Dust Mite Immunotherapy in Chinese Allergic Rhinitis Patients With Diverse Sensitization Patterns: A Multicenter Study (COVER Study).

BACKGROUND Allergen immunotherapy (AIT) is the only etiological treatment for allergic rhinitis (AR) patients, yet the impact of allergen sensitization patterns on AIT efficacy remains unclear. This study aimed to assess the effectiveness of subcutaneous immunotherapy (SCIT) using a native house dust mite (HDM) allergen extract in Chinese AR patients with diverse HDM sensitization patterns. METHODS This prospective multicenter study across three allergy centers in China enrolled patients aged 5-65 diagnosed with HDM-induced AR. Serum-specific IgE testing for nine HDM components (Der p1, Der p2, Der p23, Der f1, Der f2, Der p5, Der p7, Der p10, Der p21) categorized patients into two groups: Group A with sensitization limited to major allergen components and Group B with sensitization to minor components with or without major components. Both groups underwent 1 year of HDM SCIT (Allergopharma, Germany), whose efficacy was assessed using the visual analogue scale (VAS) and combined symptom medication scores (CSMS). Serum IgE and IgG4 levels against the nine HDM components were measured pre- and post-treatment, and SCIT-related adverse reactions were recorded. RESULTS The study enrolled 168 patients, with 75 in Group A and 93 in Group B. Group B patients had higher asthma prevalence and elevated baseline HDM sIgE and total IgE levels. After 1 year, Group B showed significantly greater CSMS reduction (67.70% vs. 59.09%, p = 0.03) and VAS improvement (66.67% vs. 50.00%, p = 0.01) compared to Group A. Group A had increased new sensitization risk to minor allergens (Der p5, Der p7, Der p21). No significant difference in SCIT efficacy was observed between patients with and without new sensitization. Both groups exhibited increased sIgG4 levels against all nine HDM allergens, with a more pronounced elevation of sIgG4 levels to Der p21 observed in Group B compared to Group A (p = 0.02). SCIT-related adverse reactions were comparable (p > 0.05). CONCLUSIONS The native HDM allergen extract demonstrates efficacy in Chinese AR patients with varying sensitization patterns. It offers enhanced benefits for patients sensitized to minor allergens with or without major allergens of HDM, positioning it as the preferred option for individuals with AR. TRIAL REGISTRATION Chinese Clinical Trial Registry identifier: ChiCTR2300078642.