Current status of sublingual immunotherapy for allergic rhinitis in Japan

Retrospective Observational Study on Telemedicine in Sublingual Immunotherapy for Patients with Japanese Cedar Pollinosis and House Dust Mite Allergic Rhinitis

Introduction: In Japan, telemedicine has gradually expanded due to deregulation in response to the COVID-19 pandemic. However, its current status remains unclear, as it is primarily provided by general practitioners. This study aims to examine the use of telemedicine in sublingual immunotherapy (SLIT) for patients with Japanese cedar pollen allergy and/or house dust mite allergic rhinitis. Methods: We conducted a retrospective analysis of medical record data from seven otorhinolaryngology clinics and performed an exploratory evaluation between a group that combined telemedicine and in-person visits during the initial 6 months of SLIT and another group with only in-person visits. Results: Following propensity score matching, 51 and 82 patients were eligible for the telemedicine and in-person groups, respectively, with 33 cases in both groups. Both groups had similar characteristics after matching. No significant difference was found in the withdrawal rate at 6 months from the start of SLIT (6.1% and 9.1% in each group; p = 1.00), side effects, or treatment efficacy between the two groups. The average copayment for patients tended to be significantly higher in the telemedicine group after one, three, and 6 months following SLIT initiation. Discussion: The situation of patients who receive an appropriate combination of telemedicine and in-person visits is not significantly different from patients who receive in-person visits alone. This study may help indicate the actual status of telemedicine in Japan. Further investigation at more facilities is necessary in the future to dispel concerns in the practice setting.

Safety of 300IR house dust mite sublingual tablet from pooled clinical trial and post-marketing data

Background

The 300IR house dust mite (HDM) sublingual immunotherapy (SLIT) tablet is approved for treatment of HDM-induced allergic rhinitis (AR). To provide a comprehensive review of the 300IR HDM-SLIT tablet safety profile based on randomized controlled trial (RCT) pooled data and post-marketing (PM) pharmacovigilance data.

Methods

Subjects (5-65 years) with confirmed HDM-AR with or without controlled asthma were treated with 300IR or placebo in 8 RCTs. Reported treatment-emergent adverse events (TEAEs) were pooled and analyzed descriptively in subsets of adults/adolescents and children. Adverse reactions (ADRs) collected from spontaneous reporting and PM studies through a pharmacovigilance system since the first marketing authorization were also analyzed.

Results

Across RCTs, 1853 subjects were treated with the 300IR HDM-SLIT tablet and 1846 with placebo. In both subsets of adults/adolescents and children whichever their asthma status, treatment-related TEAEs of higher incidence in active groups vs placebo were mostly consistent with mild or moderate local application-site reactions. They were mainly reported on the first days of treatment and decreased over time. 4 severe laryngopharyngeal reactions (2 requiring adrenaline/epinephrine) and 1 moderate eczema considered serious rapidly resolved with medications; no anaphylaxis was reported. In PM settings, ADRs reported in more than 235,000 patients were in line with RCT findings. Severe systemic reactions occurred rarely; 12 anaphylactic reactions resolved safely (5 with adrenaline). No new safety signal was raised.

Conclusion

Safety data from RCTs and more than 7 years of real-life experience confirmed the favorable safety profile of 300IR HDM-SLIT tablet in patients across different regions, regardless of age and asthma status.

Clinical trial registrations

NCT00674700; Retrospectively registered 06 May 2008.NCT01199133; Retrospectively registered 09 September 2010.NCT01527188; Retrospectively registered 01 February 2012.NCT02443805; Registered 29 April 2015/EudraCT 2014-004223-46; Registered 16 September 2015.jRCT2080221872/JapicCTI-121917; Registered 01 August 2012.jRCT2080222929/JapicCTI-15298; Registered 04 August 2015.

Increase in the prevalence of follicular regulatory T cells correlates with clinical efficacy of sublingual immunotherapy with house dust mites

BACKGROUND

Allergic rhinitis (AR) impairs quality of life and affects nearly 40% of the Japanese population. Sublingual immunotherapy (SLIT) is the disease-modifying treatment for AR, but requires the selection of a biomarker associate with clinical efficacy in patients with AR who are treated with SLIT. The present study sought to examine objective biomarkers used for assessing the clinical efficacy of SLIT.

METHODS

The authors examined the effects of 1 year of SLIT treatment with house dust mites (HDMs) using peripheral blood mononuclear cells (PBMCs) and serum from patients with AR. The prevalences of follicular regulatory T (Tfr), type 2 follicular helper T (Tfh2), type 2 helper T (Th2), conventional regulatory T (Treg), and type 1 regulatory T (Tr1) cells were examined by flow cytometry. Serum concentrations of HDM-specific IgA, IgE, and IgG4 antibodies, and HDM-induced production of interleukin (IL) 5 and IL-10 from cultured PBMCs were evaluated by enzyme-linked immunosorbent assay.

RESULTS

Following 1 year of SLIT, the prevalences of Tfr, conventional Treg, and Tr1 cells were significantly increased, whereas that of Th2 cells and Tfh2 cells were significantly decreased; the serum concentration of HDM-specific IgG4 was significantly increased; and HDM-induced production of IL-5 from PBMCs was significantly decreased, while that of IL-10 was significantly increased. The increase in the prevalence of Tfr cells after SLIT correlated positively with the improvement of clinical symptom scores.

CONCLUSION

An increase in Tfr cells may play an important role in SLIT, and may be a useful indicator for the clinical efficacy of SLIT.

Safety of Sublingual Immunotherapy: A Secondary Analysis of Post-marketing Adverse Events Reports Using a Japanese Public Database

Purpose Allergic rhinitis impacts a significant portion of the Japanese population, leading to the rise of sublingual immunotherapy (SLIT) as an alternative treatment. Despite its growing popularity, there is limited safety information. Therefore, this study aimed to consolidate data on its adverse effects in an academic context. Methods We conducted a secondary analysis of adverse events reported in the Pharmaceutical Adverse Events Information Database for three SLIT drugs (Actair®, Cedarcure®, and Miticure®) approved in Japan. A descriptive analysis concerning age, gender, underlying diseases, symptoms, time of onset, and outcomes was performed. Results We identified 98 cases of adverse reactions reported for the SLIT drugs. These cases were mainly from the pediatric to adolescent group (73.7%). Males made up 59.5% of reports. Recovery or improvement was noted in 97.7% of reports. Anaphylactic reactions were the most common adverse event (42.6%), followed by respiratory distress (12.2%). Reactions typically occurred within one week of starting treatment (54.1%). Conclusions Our research illuminated the safety of SLIT drugs in Japan, revealing a favorable profile. It underscores the need for vigilance, particularly among younger patients and during initial doses, emphasizing the importance of proper patient selection and further research to enhance the treatment's efficacy.

The Combined Effects of Sublingual Immunotherapy and Lactobacillus acidophilus-Producing Extract on Cedar Pollinosis Symptoms

INTRODUCTION

Sublingual immunotherapy (SLIT), in which standardized cedar pollen extract solution is administered, has been used to treat cedar pollinosis, but SLIT is problematic because it takes a long time to become effective, and some cases are ineffective even after long-term treatment. It has also been reported that lactobacillus acidophilus extract (LEX), a food-derived ingredient, alleviates various allergic symptoms. This study examined the usefulness of LEX as a treatment for cedar pollinosis in comparison with SLIT. We also examined whether the combined use of SLIT and LEX could have an early-onset of therapeutic effect on cedar pollinosis. We also examined the usefulness of LEX as a salvage therapy for patients who failed to respond to SLIT.

SUBJECTS AND METHODS

Fifteen patients with cedar pollinosis were divided into three groups. The three groups were: three patients in the standardized cedar pollen extract group (S group), seven patients in the lactobacillus-producing extract group (L group), and five patients in the combination group of standardized cedar pollen extract and lactobacillus-producing extract (SL group). The subjects were treated for three years, corresponding to the three scattering seasons of cedar pollen, and observed according to the evaluation items. The evaluation items were severity score based on examination findings, subjective symptom score (QOL score) based on the Japanese Standard QOL Questionnaire for Allergic Rhinitis (JRQLQ No. 1) questionnaire, nonspecific IgE level measurement by blood test, and cedar pollen-specific IgE level measurement.

RESULTS

After three years of observation, there were no significant differences in severity score and nonspecific IgE levels among the three groups, while QOL score decreased significantly between the first and third years of treatment in the L group. Cedar pollen-specific IgE levels in the S and SL groups showed an increase in the first year and a gradual decrease in the second and third years of treatment compared to the pre-treatment period. In group L, no increase was observed in the first year, and a significant decrease was observed in the second and third years during the cedar pollen dispersal period.

CONCLUSIONS

The results of severity and quality of life scores indicated that it took three years of treatment for the S and SL groups to show efficacy, while the L group showed improvement in quality of life scores and cedar pollen-specific IgE levels from the first year, suggesting that LEX is useful as a treatment for cedar pollinosis. The efficacy of combination therapy with SLIT and LEX was not clear, but since the effect of LEX was observed from the early stage of treatment, it was thought that the combination therapy with LEX intake from the early stage of treatment may be effective in reducing the incidence of ineffective cases. The combination therapy of SLIT and LEX may also be useful as a salvage therapy.

Effectiveness and safety of allergen immunotherapy in patients with allergic rhinitis complicated by rheumatic autoimmune diseases: a case series study

Background

Allergen immunotherapy (AIT) is the only treatment that has modified the natural history of allergic diseases. However, since its overall effect on the immune system has not been elucidated, AIT is either absolutely or relatively contraindicated in patients with rheumatic autoimmune diseases (RADs). Therefore, there have been no long-term observations of patients with RADs receiving AIT; thus, the effectiveness and safety of AIT in these patients remain unclear.

Methods

This was a single-center retrospective observational study. RAD patients receiving AIT for allergic rhinitis at our institution were selected. Changes in the activity of RAD patients were investigated for 2 years from baseline, including those who discontinued AIT. The effectiveness of AIT was also investigated using the Japan Allergic Rhinitis Standard Quality of Life Questionnaire.

Results

Thirteen patients with RADs were enrolled in the study. All patients received sublingual immunotherapy, of which four discontinued AIT owing to adverse events. Among all patients, the symptoms of RADs in three patients worsened during the observation period; however, none of them were causally related to AIT. Most of the adverse events associated with AIT were mild, in which only one patient required drug intervention due to worsening rhinitis symptoms. In the nine patients who were able to continue AIT, their eye and nasal symptom scores showed a significant improvement from 1.67 (1.5–2.0) at baseline to 0.67 (0–1.17) in the 2nd year of treatment (p = 0.0141).

Conclusions

AIT is a safe and effective treatment modality for patients with allergic rhinitis complicated by RADs.

Efficacy of dual sublingual immunotherapy with Japanese cedar pollen and house dust mite allergens in patients with allergic rhinitis sensitized to multiple allergens

OBJECTIVE

In the present study, we examined the effects of dual sublingual immunotherapy (SLIT) with Japanese cedar pollen (JCP) and house dust mite (HDM) allergens on nasal symptoms during the peak pollen period (PPP) and in late fall (LF) in patients with allergic rhinitis (AR) sensitized to both JCP and HDM. We then compared the efficacy of dual-SLIT with JCP and HDM to that of mono-SLIT with JCP at PPP.

METHODS

Twenty-five bisensitized patients with AR who showed positive serum specific immunoglobulin E (IgE) against both JCP and HDM were enrolled. In dual-SLIT, 16 patients received JCP drops/tablets and HDM tablets concurrently. In mono-SLIT with JCP, nine patients received JCP drops/tablets. Nasal symptoms were scored on a 0-4 point scale.

RESULTS

The nasal scores at PPP and in LF in the bisensitized patients with AR who received dual-SLIT with JCP and HDM in 2019 were significantly lower than those in the same patients who received antihistamines only in 2018. The decrease in scores of nasal obstruction at PPP from 2018 to 2019 in patients who received dual-SLIT was significantly greater than those in patients who received mono-SLIT with JCP. Dual-SLIT was well tolerated and only had mild adverse effects.

CONCLUSION

These findings suggest that dual-SLIT suppressed both JCP-induced seasonal and HDM-induced perennial nasal symptoms in bisensitized patients with AR. Dual-SLIT was more effective in suppressing nasal obstruction at PPP than mono-SLIT with JCP with limitation of baseline characteristics not to be controlled between the two groups, suggesting that dual-SLIT suppressed HDM-induced priming effects, thus resulting in further suppression of nasal obstruction at PPP.

LEVEL OF EVIDENCE

3b, a case-controlled study.

Increased Thrombin-Activatable Fibrinolysis Inhibitor in Response to Sublingual Immunotherapy for Allergic Rhinitis

OBJECTIVES/HYPOTHESIS

The objective of this study was to determine the role of thrombin-activatable fibrinolysis inhibitor (TAFI) as a candidate biomarker for therapeutic efficacy of sublingual immunotherapy (SLIT) and to identify the role of TAFI in the pathogenesis of allergic rhinitis (AR).

STUDY DESIGN

Retrospective cohort study and laboratory study.

METHODS

Serum was collected from patients with allergies to Japanese cedar pollen before, during, and after treatment with SLIT. We measured the levels of immunoreactive TAFI, C3a, and C5a in serum by enzyme-linked immunosorbent assay (ELISA) and assessed their relative impact on a combined symptom-medication score. We also examined the impact of TAFI on mast cells and fibroblasts in experiments performed in vitro.

RESULTS

Serum levels of TAFI increased significantly in response to SLIT. By contrast, serum C3a levels decreased significantly over time; we observed a significant negative correlation between serum levels of TAFI versus C3a and symptom-medication score. Mast cell degranulation was inhibited in response to TAFI, as it was the expression of both CCL11 and CCL5 in cultured fibroblasts.

CONCLUSIONS

High serum levels of TAFI may be induced by SLIT. TAFI may play a critical protective role in pathogenesis of AR by inactivating C3a and by inhibiting mast cell degranulation and chemokines expression in fibroblasts.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.

Effects of sublingual immunotherapy on nasal symptoms and sleep disturbance in patients with Japanese cedar pollinosis

OBJECTIVE

Japanese cedar (JC) pollinosis is the most common seasonal allergic rhinitis (AR) in Japan. AR reduces the quality of life not only because of nasal symptoms but also because of sleep disturbance. In the present study, we investigated the effects of sublingual immunotherapy (SLIT) with a standardized JC pollen extract on nasal symptoms and AR-related sleep disturbance in patients with JC pollinosis.

METHODS

In the present non-randomized controlled study, we assigned thirty-one patients with JC pollinosis who received SLIT into the SLIT group, and another thirty-eight patients with JC pollinosis who visited our hospital without treatment into the untreated group. We evaluated nasal symptoms and sleep disturbance using the classification of the severity of AR symptoms and the Athens Insomnia Scale, respectively.

RESULTS

The nasal symptom scores and the Athens Insomnia Scale scores of patients in the SLIT group were both significantly lower than those of patients in the untreated group. There was a significant correlation between total nasal symptom scores and the Athens Insomnia Scale scores.

CONCLUSIONS

These findings suggested that SLIT with JC pollen extract suppressed nasal symptoms in patients with JC pollinosis, leading to improvements in AR-related sleep disturbance and daytime troubles with daily life.

Mechanisms of allergen-specific immunotherapy and allergen tolerance

Allergen-specific immunotherapy (AIT) is the mainstay treatment for the cure of allergic disorders, with depicted efficacy and safety by several trials and meta-analysis. AIT impressively contributes to the management of allergic rhinitis, asthma and venom allergies. Food allergy is a new arena for AIT with promising results, especially via novel administration routes. Cell subsets with regulatory capacities are induced during AIT. IL-10 and transforming growth factor (TGF)-β are the main suppressor cytokines, in addition to surface molecules such as cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) and programmed cell death protein-1 (PD-1) within the micro milieu. Modified T- and B-cell responses and antibody isotypes, increased activity thresholds for eosinophils, basophils and mast cells and consequent limitation of inflammatory cascades altogether induce and maintain a state of sustained allergen-specific unresponsiveness. Established tolerance is reflected into the clinical perspectives as improvement of allergy symptoms together with reduced medication requirements and evolved disease severity. Long treatment durations, costs, reduced patient compliance and risk of severe, even life-threatening adverse reactions during treatment stand as major limiting factors for AIT. By development of purified non-allergenic, highly-immunogenic modified allergen extracts, and combinational usage of them with novel adjuvant molecules via new routes may shorten treatment durations and possibly reduce these drawbacks. AIT is the best model for custom-tailored therapy of allergic disorders. Better characterization of disease endotypes, definition of specific biomarkers for diagnosis and therapy follow-up, as well as precision medicine approaches may further contribute to success of AIT in management of allergic disorders.

Immunological and Symptomatic Effects of Oral Intake of Transgenic Rice Containing 7 Linked Major T-Cell Epitopes from Japanese Cedar Pollen Allergens

BACKGROUND

A rice-based peptide vaccine containing 7 linked human predominant T-cell epitopes (7Crp) derived from Japanese cedar (JC) pollen allergens, Cry j 1 and Cry j 2, was developed. Here, we examined the efficacy and safety of this transgenic rice in JC pollinosis patients.

METHODS

Transgenic rice (5, 20, and 80 g) was administered orally. We measured the T-cell proliferative activity against 7Crp, Cry j 1, and Cry j 2; the cytokine expression levels; and specific IgE and IgG4 production levels. In addition, the symptom and medication scores were monitored during the pollen season, and quality of life (QOL) was evaluated.

RESULTS

T-cell proliferative activities to Cry j 1, Cry j 2, and 7Crp were significantly depressed in a dose-dependent manner. Oral intake of 80 g transgenic rice for 20 weeks resulted in significant suppression of allergen-specific T-cell proliferation with downregulation of IL-13 and upregulation of IL-10 levels but no changes to specific IgE and IgG4 levels. The QOL symptom scores for allergic rhinitis were not significantly improved.

CONCLUSIONS

Allergen-specific T-cell responses were significantly reduced by oral intake of transgenic rice in a dose-dependent manner. However, neither medication score nor QOL symptom scores could be improved during the JC pollen season with oral intake of transgenic rice for 20 weeks.

Solid-in-Oil Nanodispersions for Transcutaneous Immunotherapy of Japanese Cedar Pollinosis

Japanese cedar pollinosis (JCP) is a common affliction caused by an allergic reaction to cedar pollen and is considered a disease of national importance in Japan. Antigen-specific immunotherapy (AIT) is the only available curative treatment for JCP. However, low compliance and persistence have been reported among patients subcutaneously or sublingually administered AIT comprising a conventional antigen derived from a pollen extract. To address these issues, many research studies have focused on developing a safer, simpler, and more effective AIT for JCP. Here, we review the novel antigens that have been developed for JCP AIT, discuss their different administration routes, and present the effects of anti-allergy treatment. Then, we describe a new form of AIT called transcutaneous immunotherapy (TCIT) and its solid-in-oil (S/O) nanodispersion formulation, which is a promising antigen delivery system. Finally, we discuss the applications of S/O nanodispersions for JCP TCIT. In this context, we predict that TCIT delivery by using a S/O nanodispersion loaded with novel antigens may offer an easier, safer, and more effective treatment option for JCP patients.

Transcutaneous Delivery of Immunomodulating Pollen Extract-Galactomannan Conjugate by Solid-in-Oil Nanodispersions for Pollinosis Immunotherapy

Japanese cedar pollinosis is a type I allergic disease and has already become a major public health problem in Japan. Conventional subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) cannot meet patients' needs owing to the side effects caused by both the use of conventional whole antigen molecules in the pollen extract and the administration routes. To address these issues, a surface-modified antigen and transcutaneous administration route are introduced in this research. First, the pollen extract (PE) was conjugated to galactomannan (PE-GM) to mask immunoglobulin E (IgE)-binding epitopes in the PE to avoid side effects. Second, as a safer alternative to SCIT and SLIT, transcutaneous immunotherapy (TCIT) with a solid-in-oil (S/O) nanodispersion system carrying PE-GM was proposed. Hydrophilic PE-GM was efficiently delivered through mouse skin using S/O nanodispersions, reducing the antibody secretion and modifying the type 1 T helper (Th1)/ type 2 T helper (Th2) balance in the mouse model, thereby demonstrating the potential to alleviate Japanese cedar pollinosis.

Mesenchymal stem cells combined with traditional Chinese medicine (qi-fang-bi-min-tang) alleviates rodent allergic rhinitis

Mesenchymal stem cells (MSCs) have been proved to exert anti-inflammatory effects and regulate immune reactions. Traditional Chinese medicine (TCM), qi-fang-bi-min-tang, is effective for some patients with allergic diseases. However, it remains unclear whether MSCs combined with TCM could benefit the treatment of allergic rhinitis (AR). In this study, we reported an additional effect of TCM (qi-fang-bi-min-tang) on the therapy of AR under MSCs treatment. Intriguingly, we observed that TCM-treated MSCs significantly inhibited the symptoms of AR and reduced the pathological changes of nasal mucosa in ovalbumin (OVA)-induced rats. The expression levels of interferon γ (IFN-γ), interleukin-17 (IL-17), and IL-4 were significantly decreased in the plasma of AR rats after injection of TCM-treated MSCs. TCM-treated MSCs reduced the levels of histamine secreted by mast cells and immunoglobulin E (IgE) secreted by plasma cells. In addition, we found that MSCs combined with TCM had a better therapeutic effect than TCM alone on AR in an OVA-induced mouse model. After OVA induction, MSCs combined with TCM significantly reduced the ratio of T helper type 1 (Th1), Th2, and Th17, but increased the proportion of Treg in the spleen of mice. Consistently, the expression levels of IFN-γ, IL-4, and IL-17 were significantly decreased, but transforming growth factor-β1 was significantly increased in the plasma of AR mice after treated with TCM and MSCs. Our results from both rats and mice indicated that the effects of TCM combined with MSCs on the AR might be through regulating the secretion of Th1, Th2, and Th17 cytokines. This study suggested that TCM (qi-fang-bi-min-tang)-treated MSCs could be used in the clinical therapy of AR.