Subcutaneous and sublingual immunotherapy (SCIT, SLIT) are the most common methods for controlling allergic rhinitis (AR). At this year's APAAACI Congress, Prof. M. Okano, MD (International University on Health and Welfare School of Medicine, Narita, Japan) presented research on the safety, efficacy and adherence of the two treatment regimens.
The prevalence of allergic rhinitis has increased in recent years, with 50% of the Japanese population suffering from AR, mainly due to Japanese cedar pollen (JCP) and house dust mite allergens (HDM). Treatment options are mainly SLIT and SCIT. Safety, efficacy and adherence are factors that can influence the choice of treatment.
The occurrence of side effects under SLIT and SCIT has been studied many times. Prof. Okano presented several studies dealing with the occurrence of adverse side effects in the context of immunotherapies:
The symptom-reducing effect of SCIT and SLIT is the subject of several research papers. Even though the results are not always congruent, SCIT seems to be more likely to lead to therapeutic success than SLIT.
In addition to the safety and efficacy of the therapy regime, high adherence is crucial for treatment success. A Dutch retrospective real-life study addressed this aspect of immunotherapy: The study showed that the discontinuation rate under SLIT was significantly higher than under SCIT (1st year of treatment: SLIT 62% vs. SCIT 20%, 3rd year of treatment SLIT 93% vs. SCIT 77%).
In contrast, adherence to SLIT seems to be much higher in Japan. In a Japanese research study, the percentage of discontinuations was only 4% in the first year of treatment and 14% in the third year. Good adherence was also associated with optimised symptom control.
According to Prof. Okano, one possible reason for the high adherence in Japan could be the national SLIT registration system. After a medical indication has been made, the sufferers must complete several information sessions and tests on the course of treatment before immunotherapy is approved. In addition, much emphasis is placed on patient education regarding SLIT, e.g. with brochures.
In clinical practice, SLIT is preferable to SCIT, as Prof. Okano emphasised. The advantage here is the good safety profile and the oral application. However, if the patient wants symptom control as quickly as possible and refuses daily treatment, SCIT should be considered. Moreover, training and information material on the understanding of autoimmune therapy are helpful to promote therapy adherence.
Okano, Prof. Dr. med. M., International University of Health and Welfare School of Medicine Narita, Japan, Symposium Immune Tolerance and Immunotherapy: SCIT and SLIT for Respiratory Allergic Diseases, Asia Pacific Association of Allergy, Asthma and Clinical Immunology (APAAACI) 2021 International Conference, 15-17.10.2021.