Efficacy of Japanese cedar pollen sublingual immunotherapy tablets for Japanese cypress pollinosis.

Background: We previously demonstrated the efficacy of Japanese cedar (JC) pollen sublingual immunotherapy (SLIT) tablets for treating seasonal allergic rhinitis in a clinical trial (trial no. 206-2-1) that covered 5 pollen dispersal seasons from 2015 to 2019. Objective: Our aim was to perform post hoc analysis of the 206-2-1 trial data to evaluate the efficacy of JC pollen SLIT tablets for patients with rhinitis induced by pollen from Japanese cypress (JCY), a related Cupressaceae species that has a pollen dispersal season overlapping with that of JC. Methods: Data were analyzed for 240 patients who received placebo during the first pollen dispersal season in 2015, were then rerandomized to receive JC SLIT tablets (the PA group) or placebo (the PP group) for 18 months (the 2016 and 2017 dispersal seasons), and were observed untreated for 2 years (the 2018 and 2019 dispersal seasons). The PA and PP groups were assigned to "high" and "low" subgroups if their rhinitis symptoms were exacerbated/did not change or decreased, respectively, during the peak JCY pollen dispersal period in 2015. The mean total nasal symptom and medication scores and other outcomes were compared for the high-PP, high-PA, low-PP, and low-PA groups during the 2016 to 2019 peak JCY pollen dispersal periods. Results: The mean total nasal symptom and medication scores were significantly lower for the high-PA and low-PA groups than for the corresponding PP groups over the 4 years of treatment and observation. JCY pollen-specific IgE levels increased in both PA groups. Conclusion: JC pollen SLIT tablets effectively suppressed JCY pollinosis symptoms, supporting the clinical relevance of immunologic cross-reactivity between JC and JCY allergens.

Prevalence of Allergic Diseases across All Ages in Japan: A Nationwide Cross-Sectional Study Employing Designated Allergic Disease Medical Hospital Network.

Introduction: Allergic diseases affect both children and adults, but generation-specific prevalence rates are unclear. Methods: An online questionnaire was used from December 2021 to January 2022 to survey the prevalence of allergic diseases among staff and their families of designated allergic disease medical hospitals in Japan. In this study, bronchial asthma (BA), atopic dermatitis (AD), food allergies (FAs), allergic rhinitis (AR), allergic conjunctivitis (AC), metal allergies (MAs), and drug allergies (DAs) were the allergic diseases surveyed. Results: In total, 18,706 individuals were surveyed (median age, 36 years; quartile range, 18-50). Allergic disease was reported in 62.2% of respondents. Across all ages, prevalence rates were as follows: BA (14.7%), AD (15.6%), FAs (15.2%), AR (47.4%), AC (19.5%), MAs (1.9%), and DAs (4.6%). The prevalence of BA and AR was higher in male children, whereas that of FAs and AC was higher in adult females. The prevalence of MAs and DAs peaked during adulthood and predominated among females. Conclusions: Our results suggest that approximately two-thirds of the Japanese population may have an allergic disease, with AR being the most prevalent.

Executive summary: Japanese guidelines for allergic rhinitis 2020.

The Practical Guideline for the Management of Allergic Rhinitis, the fist guideline for allergic rhinitis in Japan, was prepared after a symposium held by the Japanese Society of Allergology in 1993. The current 9th edition was published in 2020 and is widely used today. The most recent collection of evidence from the literature was supplemented to the revised guideline to incorporate evidence-based medicine. The revised guideline includes updated epidemiology of allergic rhinitis in Japan, a figure representing the mechanisms of allergic rhinitis in both the onset and sensitization phases with the introduction of regulatory T cells and type 2 innate lymphoid cells, practical assessment for diagnosis, new pharmacotherapy agents such as anti-IgE mAb and a new drug delivery system for antihistamines, sublingual immunotherapy for children, dual sublingual immunotherapy for house dust mites and Japanese cedar pollen extract, new classification for surgery for allergic rhinitis, and treatment and prescriptions for older adults. An evidence-based step-by-step strategy for treatment is also described.

Re-evaluation of over-the-counter histamine H1-receptor antagonists based on their effects on murine models of allergen-induced nasal hyperresponsiveness.

T cells play an essential role in the development of allergen-induced nasal hyperresponsiveness (NHR), a pathophysiological response in allergic rhinitis. The effects of histamine H1-receptor antagonists (antihistamines) on murine NHR models were investigated. Intragastric epinastine, fexofenadine, and loratadine administration suppressed allergen-induced immediate nasal response but not NHR in immunized mice. Regardless of the alleviation of stimulation-induced Th2 cytokine expression by loratadine and desloratadine in vitro, allergen-induced NHR and nasal eosinophil infiltration in Th2 cell-transferred mice were unaffected by loratadine in vivo. This influence on T cell-mediated NHR was excluded from the pharmacological effects of antihistamines.

Disease-Modifying Effect of Japanese Cedar Pollen Sublingual Immunotherapy Tablets.

BACKGROUND: Japanese cedar (JC) pollinosis is a common allergic rhinitis in Japan. JC pollen sublingual immunotherapy (SLIT) tablets are licensed for the treatment of JC pollinosis. OBJECTIVE: To assess the disease-modifying effects of JC pollen SLIT tablets over 5 years (2014-2019), comprising a 3-year treatment period and 2-year follow-up. METHODS: A total of 1042 patients with JC pollinosis (aged 5-64 years) were included in the study. An optimal dose-finding study was performed in the first 15 months, after which 240 patients in the placebo (P) group and 236 patients in the optimal active dose (A) group (5000 Japanese allergy units) were re-randomized to receive P or A for an additional 18 months (designated AA, AP, PA, and PP groups). Clinical efficacy was evaluated by the total nasal symptom and medication score (TNSMS) during the peak symptom period of each JC pollen season over 3 years of treatment and 2 years of observation after treatment cessation. RESULTS: The AA, AP, and PA groups exhibited significantly reduced TNSMS; however, the largest relative reduction was seen in the AA group both during the treatment period (third season, 46.3% vs PP, P < .001) and during the 2-year follow-up period (fourth and fifth seasons, 45.3% and 34.0% vs PP, respectively; P < .001). The most common adverse drug reactions were mild reactions at the administration site. CONCLUSIONS: JC pollen SLIT tablets show sustained clinical efficacy during 3 years of treatment and sustained disease-modifying effects for at least 2 years after treatment cessation.

Long-term sublingual immunotherapy provides better effects for patients with Japanese cedar pollinosis.

OBJECTIVE: Japanese cedar pollinosis is an endemic disease affecting a large proportion of Japan's population. Five seasons have passed since sublingual immunotherapy (SLIT) for Japanese cedar pollinosis was included in the public insurance coverage in Japan. In this study, we evaluated the clinical effects of long-term SLIT for Japanese cedar pollinosis on upper respiratory symptoms primarily represented by nasal symptoms and inflammation of the respiratory tract in the 2019 season, in which considerable amount of cedar pollen was dispersed. METHODS: This study involved 95 patients who were undergoing SLIT for Japanese cedar pollinosis after the initiation at some point between 2014 and 2018, and this group of patients was compared with a control group comprising 21 patients receiving preseasonal prophylactic treatment (with a second-generation antihistaminic drug). We evaluated the patients' nasal/eye symptoms, total nasal symptom and medication score (TNSMS), and quality of life according to relevant guidelines. In addition, the levels of peripheral blood eosinophils, serum total IgE, Japanese cedar antigen-specific IgE, Cryj1-specific IgG4, and fractional exhaled nitric oxide (FENO) were measured as objective indices. RESULTS: From the fourth season (SLIT4), nasal discharge, sneezing, nasal obstruction symptoms, and TNSMS significantly decreased compared with those in the preseasonal prophylactic treatment and SLIT1 groups. In the patients suspected to have eosinophilic airway inflammation (with a baseline FENO ≥25 ppb), the interannual variability of FENO levels significantly reduced after 5 years of treatment. CONCLUSION: The efficacy of SLIT was noted from the first year of treatment, even in a year when pollen profusely dispersed. Thus, long-term continuous treatment with SLIT may alleviate nasal symptoms as well as eosinophilic airway inflammation.

Sublingual Immunotherapy: How Sublingual Allergen Administration Heals Allergic Diseases; Current Perspective about the Mode of Action.

Owing to the successful application of sublingual immunotherapy (SLIT), allergen immunotherapy (AIT) has become one of the leading treatments for allergic diseases. Similar to the case with other AITs, such as subcutaneous and oral immunotherapies, not only the alleviation of allergic symptoms, but also the curing of the diseases can be expected in patients undergoing SLIT. However, how and why such strong efficacy is obtained by SLIT, in which allergens are simply administered under the tongue, is not clearly known. Various potential mechanisms, including the induction of blocking antibodies, T cell tolerance, regulatory B and T cells, CD103-CD11b+ classical dendritic cells, and CD206+ macrophages, and the reduction of innate lymphoid cells, mast cells, and basophils, have been suggested. Recently, through a comparative analysis between high- and non-responder patients of SLIT, we have successfully proposed several novel mechanisms. Here, we introduce our recent findings and summarize the current understanding of the mechanisms underlying the strong efficacy of SLIT.

Association of Basophil-Expressing Genes with Effectiveness of Sublingual Immunotherapy.

Basophils were reported to be associated with allergy pathogenesis and the efficacy of allergen immunotherapy. Using a purified cedar allergen, we recently studied the effectiveness of sublingual immunotherapy for patients with Japanese cedar pollinosis. Patients were classified as high responders (HR) and nonresponders (NR), and comprehensive microarray analysis was used to examine peripheral basophils in both groups. A total of 153 genes were differentially expressed in HR and NR patients. Most of these differentially expressed genes encoded intracellular molecules, and expression levels were higher in HR patients than in NR patients. mRNA expression of the gene encoding D4, zinc, and double plant homeodomain (PHD) fingers family 2 (DPF2) was significantly correlated with copy number variation (CNV). Genetic variation in the DPF2 gene and its expression in basophils might be associated with the efficacy of sublingual immunotherapy.

Safety profile and immunological response of dual sublingual immunotherapy with house dust mite tablet and Japanese cedar pollen tablet.

BACKGROUND: There have been no studies of dual administration of sublingual immunotherapy (SLIT) tablets for perennial and seasonal allergic rhinitis. This trial (JapicCTI-184014) was conducted to investigate the safety profile and immunological response during dual therapy with SQ house dust mite (HDM) and Japanese cedar pollen (JCP) SLIT tablets. METHODS: This was a multicenter, open-label, randomized trial of 109 Japanese patients with coexisting HDM and JCP allergic rhinitis who had positive tests for HDM- and JCP specific IgE (≥0.7 kU/L). Patients were allocated to receive HDM (N = 54) or JCP (N = 55) SLIT tablets alone for 4 weeks followed by 8 weeks of dual therapy with both SLIT tablets administered within 5 min of each other. Adverse events (AEs), adverse drug reactions (ADRs), and serum IgE and IgG4 specific for HDM (Dermatophagoides farinae, Dermatophagoides pteronyssinus) and JCP were recorded. RESULTS: The percentage of subjects with AEs and ADRs was similar between the two groups and between the two periods of monotherapy and dual therapy. Most AEs and ADRs were mild in severity, and no serious events were observed. The most common ADRs were local events in the oral cavity. Levels of IgE and IgG4 specific for HDM (D. farinae, D. pteronyssinus) and JCP were increased after treatment with HDM and JCP SLIT tablets, respectively. CONCLUSIONS: Dual therapy with both SLIT tablets administered within 5 min after 4 weeks of monotherapy with HDM or JCP tablet was well tolerated and induced the expected immunological responses.

[Mechanisms of allergen immunotherapy elucidated through integrated comparative analysis].

From the era of subcutaneous immunotherapy (SCIT) in 1960s, allergen immunotherapy (AIT) has been established as a highly effective and curable treatment for allergic diseases. Furthermore, the recent appearance of sublingual immunotherapy (SLIT) in which the complicated administration procedure in SCIT was improved has been causing paradigm shifts in the treatment of allergic rhinitis. During the long history of AIT, the mechanisms by which this therapy leads its strong efficacy have been investigated but not fully clarified yet. The production of blocking antibodies that interrupt allergen-IgE binding, normalization of Th1/Th2 balance, and introduction of regulatory T cells are the major candidate mechanisms, though there are several conflicting reports. In our recent clinical study of SLIT against Japanese cedar pollinosis, we also tried to elucidate its mechanisms. Especially by comparing high-responder and non-responder patients using integrated analysis with multiple data, not by comparing with a placebo control group using individual data, we have successfully identified several target molecules and cascades of SLIT. Herein, we would like to describe the potential mechanisms by which AIT exhibits its strong efficacy with referring our recent novel findings.

Treatment duration-dependent efficacy of Japanese cedar pollen sublingual immunotherapy: Evaluation of a phase II/III trial over three pollen dispersal seasons.

BACKGROUND: We conducted a randomized, placebo-controlled, double-blind clinical trial to investigate the optimal dose and long-term efficacy and safety of Japanese cedar (JC) pollen tablets for SLIT (JapicCTI-142579). Here, we report details of the effects of the JC pollen SLIT tablet on rhinitis and conjunctivitis symptoms over three pollen dispersal seasons. METHODS: A total of 1042 JC pollinosis patients (aged 5-64 years) were randomized to receive tablets containing placebo (P), 2000, 5000, or 10,000 Japanese allergy units (JAU) of JC pollen for 15 months to identify an optimal dose. Patients receiving P (n = 240) and the optimal dose (5000 JAU; A, n = 236) were then randomized to receive P or A for an additional 18 months (AA, AP, PA, and PP groups, allocation ratio 2:1:1:2). Nasal and ocular symptoms, rescue medication use, and quality of life (QOL) were assessed on quantitative scales. RESULTS: In the second and third seasons, the AA, AP, and PA groups exhibited significantly better improvements in nasal, ocular, and medication scores compared with the PP group in the order AA > AP > PA > PP during the second season and AA > PA > AP > PP during the third season. Rescue medication use and QOL scores were also significantly better in the AA, AP, and PA groups compared with the PP group. CONCLUSIONS: The JC pollen SLIT tablet relieved nasal and ocular symptoms and medication use and improved QOL in a treatment duration-dependent manner. Continuous dosing regimens appear to enhance the efficacy of the drug.

Long-Term Efficacy and Dose-Finding Trial of Japanese Cedar Pollen Sublingual Immunotherapy Tablet.

BACKGROUND: Japanese cedar (JC) pollinosis is a common allergic rhinitis in Japan. The JC pollen sublingual immunotherapy (SLIT) tablet was developed using the highest concentration of JC pollen extract. OBJECTIVE: This was a randomized, double-blind, placebo-controlled phase II/III trial to investigate the optimal dose of the JC pollen SLIT tablet and examine long-term efficacy and safety for 3 years with the selected dose, and 2-year follow-up. METHODS: A total of 1042 patients with JC pollinosis (aged 5-64 years) were equally randomized into 4 groups and received daily treatment with 2,000, 5,000, or 10,000 Japanese allergy unit (JAU) or placebo. The primary end point was the total nasal symptom and medication score (TNSMS) during the peak symptom period in the first season. Key secondary end points were TNSMS for the JC pollen dispersion season and total nasal and ocular symptom and medication score for the peak symptom period and JC pollen dispersion season. RESULTS: For the primary end point, absolute reductions and relative mean reductions in TNSMS compared with placebo were 1.50 and 21.4%, 2.24 and 32.1%, and 2.18 and 31.2% for 2,000, 5,000, and 10,000 JAU, respectively (P < .001 in all groups). For all key secondary end points, efficacy was confirmed for all doses (P < .001 in all groups). The treatment was well tolerated. Long-term efficacy of 5,000 JAU was shown over the 3 years. CONCLUSIONS: The optimal dose of the JC pollen SLIT tablet was 5,000 JAU, with good efficacy and safety over a 3-year treatment period. This sustained effect was dependent on treatment duration.

Serum Cytokine Interactions Are Implicated in the Mechanism of Action of Sublingual Immunotherapy for Japanese Cedar Pollinosis.

OBJECTIVE: This study aimed to investigate whether interactions between multiple serum cytokines may be implicated in the mechanism of action (MOA) of sublingual immunotherapy (SLIT) for Japanese cedar pollinosis. METHODS: A Tokyo Metropolitan Bureau of Social Welfare and Public Health-initiated clinical study of active SLIT involving 202 patients with Japanese cedar pollinosis was jointly conducted by Tokyo Metropolitan Institute of Medical Science and Nippon Medical School between 2006 and 2008. Fifty target cytokines were quantified in serum samples collected at 6 times from baseline to the end of the study, for 300 cytokine measurements in total, using Bio-Plex Pro Human Cytokine Group I/II Panels. Therapeutic outcome was assessed based on nasal symptom scores and quality-of-life questionnaire results. RESULTS: Fifty-five percent of patients were free of symptoms or reported symptomatic improvements by 2 grades or greater after 2 years of SLIT treatment, while 27% showed no improvement or worsening of symptoms. Thirty-eight patients who benefited the most from treatment (responders) as well as 37 patients who benefited the least from treatment (non-responders) were identified and their serum cytokine profiles were compared. Cluster analysis of the 300 cytokine measurements identified 6 cytokine clusters that were strongly correlated with a positive response to treatment, and this correlation was consistent throughout the treatment. CONCLUSION: Certain cytokine clusters are strongly correlated with a positive therapeutic outcome, suggesting they have a role in the MOA of immunotherapy.