Predictive methods for efficacy of house dust mite subcutaneous immunotherapy in allergic rhinitis patients: a prospective study in a Chinese population

Background Allergen-specific immunotherapy (AIT) is the only available treatment that can induce specific immune tolerance to allergens. However, the treatment course lasts >3 years, and there is no reliable method to predict treatment response. Therefore, in this study we aimed to establish a method that can predict treatment response to AIT in the second year. Methods This prospective study enrolled 119 patients who had undergone 2-years of standard-quality house dust mite subcutaneous immunotherapy. Clinical characteristics, skin-prick test response, and treatment response were evaluated at months 4, 6, 12, and 18. Effective AIT was defined as a 25% reduction in average adjusted symptom score (AAdSS) from baseline at the end of the second year of immunotherapy. Results The overall efficacy rate at the end of year 2 of the AIT was 67.4%. Age, sex, asthma, body mass index, smoking history, and aeroallergen categories were not associated with efficacy of AIT. Meanwhile, efficacy data at month 4 (odds ratio [OR], 4.250; p = 0.004), month 6 (OR, 10.476; p < 0.000), month 12 (OR, 18.000; p < 0.000), and month 18 (OR, 9.716; p < 0.000) were associated with month 24 efficacy. The area under the curve for improvement at 4, 6, 12, and 18 months was 0.805, 0.834, 0.837, and 0.854, respectively. Conclusion Efficacy of AIT at months 4, 6, 12, and 18 is strongly associated with efficacy at month 24. Efficacy as early as month 4 can predict efficacy at the second year, and this may help to determine the need for long-term treatment. Our findings may be useful for identifying novel treatment strategies for AIT.