Long-term Efficacy of Specific Immunotherapy on House Dust Mite-Induced Allergic Rhinitis in China

Objective Although the effect of specific immunotherapy (SIT) on allergic rhinitis (AR) has been well documented in developed countries, its long-term efficacy in patients in developing countries (such as China) is poorly understood. This study investigated the long-term therapeutic and preventive effects of SIT on house dust mite (HDM)-induced AR in patients from China. Design Historical cohort study. Setting University hospital. Subjects and Methods One hundred forty-six AR patients with/without asthma allergic to HDM were investigated for 5 years after initiation of a 3-year course of subcutaneous SIT (SIT group, n = 106) or no SIT (control group, n = 40). The clinical responses of all patients were evaluated at baseline, the stop point of SIT (third year), and 2 years after SIT termination (fifth year), by clinical index including symptom and rescue medication scores (SMS), visual analog scale (VAS), total immunoglobulin E (tIgE), and specific IgE (sIgE). Asthma was assessed by clinical evaluation. Results The decrease of SMS and VAS from baseline was significantly improved in the SIT group compared with controls at both the third and fifth year. For patients without asthma at baseline, the odds ratio for no asthma was 3.57 (95% confidence interval, 1.05-12.91; P < .05) in favor of SIT. The serum sIgE/tIgE ratio was significantly increased after SIT treatment in the SIT group, but it was not related to SIT efficacy. Conclusion SIT has a long-term effect of improving clinical symptoms and reducing the risk of development of asthma in Chinese AR patients.