Study design
This multicenter, two-armed, real-world study included patients with AR and IgE-mediated sensitization to dermatophagoides pteronyssinus(Dp) and/or dermatophagoides farinae (Df). Patients were undergoing ongoing SCIT with a treatment visit during the period between February 1 and May 31, 2020 (during the COVID-19 outbreak in China) for the first visit (V0) and for follow-up 1-year later (V1). They were enrolled from the departments of otorhinolaryngology from five tertiary hospitals (in three provinces in southern China), including Zhujiang Hospital of Southern Medical University, the Third People’ s Hospital of Changzhou, the First People’s Hospital of Foshan, the People’s Hospital of Guangxi Zhuang Autonomous Region and Liuzhou People’s Hospital. Approval to conduct this study was obtained from the institutional review board of all participating hospitals. The patients in this study were all from hospitals not designated for COVID-19 infected patients. Special measures were performed to prevent patients with a COVID-19 infection from entering the hospitals. The patients received at least one reminder call a week prior to their SCIT appointment.
A standard protocol for SCIT ® (50% Dp and 50% Df, Allergopharma Joachim Ganzer KG, Reinbek, Germany) was used for all patients in both the build-up and maintenance phases. For the build-up phase, SCIT® dose was gradually increased every 1-2 weeks until the maximum tolerated dose for the individual was reached, and the treatment for a total of 18 weeks including the dose increases.. In the build-up phase, injections at an interval of more than 2 weeks were regarded as delayed treatment. For the maintenance phase, the maximum tolerated dose was given subcutaneously every 4-6 weeks for at least 2 years. During the maintenance phase, injections at an interval of more than 6 weeks were regarded as a delayed treatment. The dosage adjustment plan in the case of delayed treatment for SCIT patients in the build-up phase was as follows: (1) > 2 weeks, the dose was adjusted to 50% of the last dose; > 4 weeks, start again from the initial dose concentration. The dosage adjustment plan in the case of delayed treatment for SCIT patients in the maintenance phase was: (1) > 6 to 8 weeks, the dose was adjusted to 50% of the last dose; (2) > 8 weeks, the dose was adjusted to 5% of the last dose; (3) > 52 weeks, and the treatment was resumed from the starting concentration. The course of SCIT in this study was at least 3 years.