Formation of IgE-Allergen-CD23 Complex Changes in Children Treated with Subcutaneous Immunotherapy for Japanese Cedar Pollinosis.

BACKGROUND: Subcutaneous immunotherapy (SCIT) is used to treat Japanese cedar (JC) pollinosis. The formation of IgE-allergen-CD23 complex after SCIT for JC pollinosis has not yet been fully elucidated. OBJECTIVE: The objective of this study was to investigate the formation of IgE-allergen-CD23 complex after SCIT for JC pollinosis. METHODS: Eleven patients were treated with 3-year SCIT for JC pollinosis at Sa-gamihara National Hospital from 2013 to 2014. Nasal and ocular symptoms (in terms of symptom scores) during the scattering of JC pollen and immunological changes were investigated. Levels of JC pollen-specific antibodies (IgE and IgG4) were measured by ImmunoCAP assays. To detect the changes in allergen-presenting ability of B cells, the levels of IgE-allergen-CD23 complexes in serum were measured by a cell-free, enzyme-linked immunosorbent-facilitated antigen-binding assay. RESULTS: The median (interquartile range) age of the subjects was 8 (6-10) years. Three patients (27%) had comorbid atopic dermatitis, and 5 patients (45%) had comorbid bronchial asthma. Before starting SCIT, the total IgE level was 373 (75-2,870) kU/L, and the level of JC pollen-specific IgE was 77.2 (15.4-528) kUA/L. Symptom scores improved significantly from the year after treatment. JC pollen-specific IgE levels did not change after 3 years of treatment. JC pollen-specific IgG4 levels increased significantly throughout the treatment period. The levels of IgE-allergen-CD23 complexes decreased significantly after 3 years of treatment. CONCLUSION: The ability of IgE-allergen complexes to bind to CD23 decreased after SCIT, suggesting that increasing levels of IgE-blocking antibodies, including IgG4, may play an important role in the mechanism of SCIT.

Long-term treatment of Japanese cedar pollinosis with Japanese cedar pollen SLIT drops and persistence of treatment effect: A post-marketing clinical trial.

BACKGROUND: There have been no reports of treatment effect persistence after long-term sublingual immunotherapy (SLIT) in patients with Japanese cedar (JC) pollinosis. Therefore, we conducted a post-marketing clinical trial to investigate the efficacy, safety, and effect persistence of JC pollen SLIT drops after approximately 3 years of treatment. METHODS: This was an open-label trial of 233 patients with JC pollinosis who were treated with JC pollen SLIT drops for approximately 3 years (2015-2017) and followed-up for an additional 2 years (2018-2019). Efficacy and effect persistence were evaluated using nasal and ocular symptom scores, daily use of rescue medication, and Japanese Rhinoconjunctivitis Quality of Life Questionnaire scores recorded during the JC pollen dispersal season of each year. Safety was evaluated by monitoring adverse events and adverse drug reactions. RESULTS: The mean combined total nasal symptom and medication score (range 0-18) during the peak symptom periods of 2015 through 2019 were 5.47 ± 3.38, 4.52 ± 3.13, 3.58 ± 2.63, 5.28 ± 4.01, and 6.83 ± 4.65, respectively. The percentage of patients who used no rescue medications during the same periods was 64.8%, 75.2%, 80.3%, 63.7%, and 50.3%, respectively. A total of 138 adverse drug reaction incidents were recorded in 73 of the 233 patients (31.3%), of which 134 incidents (97.1%) were mild in severity. CONCLUSIONS: JC pollen SLIT drops demonstrated treatment duration-dependent efficacy with effects that persisted for 2 years after cessation of treatment. The drug had a favorable safety profile over the 5-year study period.