Allergen immunotherapy for asthma prevention: A systematic review and meta-analysis of randomized and non-randomized controlled studies

AllergoOncology: Biomarkers and refined classification for research in the allergy and glioma nexus-A joint EAACI-EANO position paper

Epidemiological studies have explored the relationship between allergic diseases and cancer risk or prognosis in AllergoOncology. Some studies suggest an inverse association, but uncertainties remain, including in IgE-mediated diseases and glioma. Allergic disease stems from a Th2-biased immune response to allergens in predisposed atopic individuals. Allergic disorders vary in phenotype, genotype and endotype, affecting their pathophysiology. Beyond clinical manifestation and commonly used clinical markers, there is ongoing research to identify novel biomarkers for allergy diagnosis, monitoring, severity assessment and treatment. Gliomas, the most common and diverse brain tumours, have in parallel undergone changes in classification over time, with specific molecular biomarkers defining glioma subtypes. Gliomas exhibit a complex tumour-immune interphase and distinct immune microenvironment features. Immunotherapy and targeted therapy hold promise for primary brain tumour treatment, but require more specific and effective approaches. Animal studies indicate allergic airway inflammation may delay glioma progression. This collaborative European Academy of Allergy and Clinical Immunology (EAACI) and European Association of Neuro-Oncology (EANO) Position Paper summarizes recent advances and emerging biomarkers for refined allergy and adult-type diffuse glioma classification to inform future epidemiological and clinical studies. Future research is needed to enhance our understanding of immune-glioma interactions to ultimately improve patient prognosis and survival.

Pre-asthma: a useful concept? A EUFOREA paper. Part 2-late onset eosinophilic asthma

The concept of pre-diabetes has led to provision of measures to reduce disease progression through identification of subjects at risk of diabetes. We previously considered the idea of pre-asthma in relation to allergic asthma and considered that, in addition to the need to improve population health via multiple measures, including reduction of exposure to allergens and pollutants and avoidance of obesity, there are several possible specific means to reduce asthma development in those most at risk (pre- asthma). The most obvious is allergen immunotherapy (AIT), which when given for allergic rhinitis (AR) has reasonable evidence to support asthma prevention in children (2) but also needs further study as primary prevention. In this second paper we explore the possibilities for similar actions in late onset eosinophilic asthma.

Remission in asthma

PURPOSE OF REVIEW

To review the current concepts of remission in asthma.

RECENT FINDINGS

Until 2023, asthma guidelines have been promoting the concept of disease control, recommending the step-wise addition of drugs until the best possible disease control is achieved. With the advent of highly effective, anti-inflammatory disease-modifying antiasthmatic drugs (DMAADs), treatment goals of asthma have changed. Several national guidelines have now announced remission as a general treatment goal in asthma. Currently, all guidelines agree that asthma remission is defined by the presence of at least three characteristics over a period of at least one 1 year: absence of exacerbations, no systemic corticosteroid use for the treatment of asthma and minimal asthma-related symptoms. In the future, a generally accepted, evidence-based and easy-to-use definition of remission will be needed for daily clinical practice. It is clear, however, that precise phenotyping (including measurement of biomarkers) is an essential prerequisite to achieve clinical remission in each individual patient.

SUMMARY

Remission has been included as the treatment goal in asthma in several national guidelines, reflecting the paradigm shift in asthma, from short-term symptom control to long-term symptom prevention. An international consensus on the criteria for asthma remission is expected in the near future.

[Allergen immunotherapy for rare allergens]

Among allergies to aeroallergens, approximately 20% are allotted to the so-called rare allergens. These include ash pollen, weed pollen, storage mites, molds, and animal allergens. The prevalences of allergies to these allergens are lower, but affected patients also suffer considerably from their "rare" allergy. Hence, these allergies should neither be overseen nor completely forgotten in daily practice. Especially mold, mite, and animal allergens often induce asthma, so that the significance of allergen-specific immunotherapy (AIT) should not be neglected in causal therapy. This work summarizes the current state of knowledge on the groups of rare aeroallergens in terms of characteristics, prevalences, and data on AIT. It is based on a systematic literature search performed in the MEDLINE (PubMed®) and Google Scholar databases. AIT preparations for rare allergens are classified as individual formulations and are not subject to the German Therapy Allergen Ordinance. Due to the low case numbers, the levels of evidence for these formulations are not as high as those for dust mites, grass, or birch pollen, but exhibit good efficacy in practical experience.

Preventive allergen immunotherapy with inhalant allergens in children

The efficacy and safety of preventive allergen immunotherapy (pAIT) in children are currently under investigation. Here, we provide an overview of pAIT with respiratory allergens concerning the prevention of new sensitizations, allergic disease onset and progression as well as further immunomodulatory effects. Three databases were searched for clinical pAIT studies in children. Selected publications were reviewed for preventive outcomes according to prevention level (primary, secondary, and tertiary), allergen type, administration route, dose, and treatment duration. The primary prevention approach appears safe but showed no allergen-specific effect on new sensitizations. Secondary prevention seems feasible and may induce regulatory T cell-mediated immunotolerance. The number of studies at these prevention levels is limited. Tertiary prevention with grass and/or tree pollen-based pAIT has shown efficacy in preventing disease progression from allergic rhinitis/conjunctivitis to asthma. Data on tertiary pAIT with house dust mites and other allergen types are inconclusive. Subcutaneous and sublingual routes appear similarly effective, but head-to-head comparative paediatric studies are scarce. Additionally, there are fewer placebo-controlled studies. Nevertheless, immunomodulatory outcomes of pAIT are encouraging. Currently, limited but favourably suggestive evidence is available for preventing respiratory allergic diseases in children by pAIT. Primary and secondary prevention have potential and warrant further investigation through well-designed studies.

House dust mite SCIT reduces asthma risk and significantly improves long-term rhinitis and asthma control-A RWE study

BACKGROUND

The German Therapy Allergen Ordinance (TAO) triggered an ongoing upheaval in the market for house dust mite (HDM) allergen immunotherapy (AIT) products. Three HDM subcutaneous AIT (SCIT) products hold approval in Germany and therefore will be available after the scheduled completion of the TAO procedure in 2026. In general, data from clinical trials on the long-term effectiveness of HDM AIT are rare. We evaluated real-world data (RWD) in a retrospective, observational cohort study based on a longitudinal claims database including 60% of all German statutory healthcare prescriptions to show the long-term effectiveness of one of these products in daily life. Aim of this analysis was to provide a per product analysis on effectiveness of mite AIT as it is demanded by international guidelines on AIT.

METHODS

Subjects between 5 and 70 years receiving their first (index) prescription of SCIT with a native HDM product (SCIT group) between 2009 and 2013 were included. The exactly 3:1 matched control group received prescriptions for only symptomatic AR medication (non-AIT group); the evaluation period for up to 6 years of follow-up ended in February 2017. Study endpoints were the progression of allergic rhinitis (AR) and asthma, asthma occurrence and time to the onset of asthma after at least 2 treatment years.

RESULTS

In total, 892 subjects (608 adults and 284 children/adolescents) were included in the SCIT group and 2676 subjects (1824 adults and 852 children/adolescents) in the non-AIT group. During the follow-up period after at least 2 years of SCIT, the number of prescriptions in the SCIT group was reduced by 62.8% (p < .0001) for AR medication and by 42.4% for asthma medication (p = .0003). New-onset asthma risk was significantly reduced in the SCIT vs non-AIT group by 27.0% (p = .0212). The asthma-preventive effect of SCIT occurred 15 months after start of the treatment. In the SCIT group, the time to onset of asthma was prolonged compared to the non-AIT group (p = .0010).

CONCLUSION

In this first product based RWD analysis on SCIT with a native HDM product, patients aged 5 to 70 years benefited from AIT in the long term in terms of reduced progression of AR and asthma after at least 2 years of treatment. The effects seemed to last for up to 6 years after treatment termination. A significantly reduced risk of asthma onset was observed, starting after 15 months of treatment.

Long-term effects of pollen allergoid tyrosine-adsorbed subcutaneous immunotherapy on allergic rhinitis and asthma

BACKGROUND

Allergen immunotherapy (AIT) may have a long-term disease-modifying effect. The aim of this study was to demonstrate the long-term effects of pollen allergoid tyrosine-adsorbed subcutaneous AIT on allergic rhinitis (AR) and asthma (AA) in clinical practice.

METHODS

This retrospective study, funded by an AIT manufacturer, analysed the impact of AIT on AR progression and onset of need for AA medication, using a German database covering ~35% of national prescriptions during 2008-2020. Anonymized prescription data of AR patients aged 5-65 years treated with grass or tree pollen AIT between 2009 and 2013 and followed for at least 2 years after AIT cessation were compared with matched control patients with seasonal AR.

RESULTS

181,496 patients received AIT prescriptions. 5959 fulfilled the inclusion criteria. The median AIT treatment duration was 1092 days and the follow-up duration was 6.4 years. Less patients treated with AIT received prescriptions for symptomatic AR medication in the follow-up versus controls (AIT: OR: 0.37; 95% Confidence Interval (CI) 0.34, 0.40; p < .001, tyrosine-adsorbed AIT: OR: 0.27; 95% CI 0.20, 0.35 p < .001). Less asthmatic patients under AIT received prescriptions for AA medications versus controls (AIT: OR: 0.48; 95% CI 0.41, 0.55; p < .001, tyrosine-adsorbed AIT: OR: 0.48; 95% CI 0.29, 0.79; p = .004). AR and AA medication prescriptions for AIT patients were reduced in the follow-up versus baseline and controls (AIT: AR: 20.0%; 1.5 vs. 0.2 prescriptions; AA: 29.1%; 2.0 vs. 0.6 prescriptions, p < .001; tyrosine-adsorbed AIT: AR: 24.2%, 1.4 vs. 0.2 prescriptions; AA: 35.6%, 2.1 vs. 0.6 prescriptions, p < .001). The probability of AA medication onset in non-asthmatic patients during follow-up was reduced for AIT patients compared to controls (OR: 0.77, 95% CI 0.66, 0.90; p = .001). All endpoints were significant for children/adolescents and adults in stratified analyses.

CONCLUSIONS

We found evidence for long-term effects up to 9.5 years for tyrosine-adsorbed AIT.

Clinical Practice Guideline: Immunotherapy for Inhalant Allergy

OBJECTIVE

Allergen immunotherapy (AIT) is the therapeutic exposure to an allergen or allergens selected by clinical assessment and allergy testing to decrease allergic symptoms and induce immunologic tolerance. Inhalant AIT is administered to millions of patients for allergic rhinitis (AR) and allergic asthma (AA) and is most commonly delivered as subcutaneous immunotherapy (SCIT) or sublingual immunotherapy (SLIT). Despite its widespread use, there is variability in the initiation and delivery of safe and effective immunotherapy, and there are opportunities for evidence-based recommendations for improved patient care.

PURPOSE

The purpose of this clinical practice guideline (CPG) is to identify quality improvement opportunities and provide clinicians trustworthy, evidence-based recommendations regarding the management of inhaled allergies with immunotherapy. Specific goals of the guideline are to optimize patient care, promote safe and effective therapy, reduce unjustified variations in care, and reduce the risk of harm. The target patients for the guideline are any individuals aged 5 years and older with AR, with or without AA, who are either candidates for immunotherapy or treated with immunotherapy for their inhalant allergies. The target audience is all clinicians involved in the administration of immunotherapy. This guideline is intended to focus on evidence-based quality improvement opportunities judged most important by the guideline development group (GDG). It is not intended to be a comprehensive, general guide regarding the management of inhaled allergies with immunotherapy. The statements in this guideline are not intended to limit or restrict care provided by clinicians based on their experience and assessment of individual patients.

ACTION STATEMENTS

The GDG made a strong recommendation that (Key Action Statement [KAS] 10) the clinician performing allergy skin testing or administering AIT must be able to diagnose and manage anaphylaxis. The GDG made recommendations for the following KASs: (KAS 1) Clinicians should offer or refer to a clinician who can offer immunotherapy for patients with AR with or without AA if their patients' symptoms are inadequately controlled with medical therapy, allergen avoidance, or both, or have a preference for immunomodulation. (KAS 2A) Clinicians should not initiate AIT for patients who are pregnant, have uncontrolled asthma, or are unable to tolerate injectable epinephrine. (KAS 3) Clinicians should evaluate the patient or refer the patient to a clinician who can evaluate for signs and symptoms of asthma before initiating AIT and for signs and symptoms of uncontrolled asthma before administering subsequent AIT. (KAS 4) Clinicians should educate patients who are immunotherapy candidates regarding the differences between SCIT and SLIT (aqueous and tablet) including risks, benefits, convenience, and costs. (KAS 5) Clinicians should educate patients about the potential benefits of AIT in (1) preventing new allergen sensitizations, (2) reducing the risk of developing AA, and (3) altering the natural history of the disease with continued benefit after discontinuation of therapy. (KAS 6) Clinicians who administer SLIT to patients with seasonal AR should offer pre- and co-seasonal immunotherapy. (KAS 7) Clinicians prescribing AIT should limit treatment to only those clinically relevant allergens that correlate with the patient's history and are confirmed by testing. (KAS 9) Clinicians administering AIT should continue escalation or maintenance dosing when patients have local reactions (LRs) to AIT. (KAS 11) Clinicians should avoid repeat allergy testing as an assessment of the efficacy of ongoing AIT unless there is a change in environmental exposures or a loss of control of symptoms. (KAS 12) For patients who are experiencing symptomatic control from AIT, clinicians should treat for a minimum duration of 3 years, with ongoing treatment duration based on patient response to treatment. The GDG offered the following KASs as options: (KAS 2B) Clinicians may choose not to initiate AIT for patients who use concomitant beta-blockers, have a history of anaphylaxis, have systemic immunosuppression, or have eosinophilic esophagitis (SLIT only). (KAS 8) Clinicians may treat polysensitized patients with a limited number of allergens.

Plain Language Summary: Immunotherapy for Inhalant Allergy

The plain language summary explains allergen immunotherapy to patients, families, and caregivers. The summary is for patients aged 5 years and older who are experiencing symptoms from inhalant allergies and are considering immunotherapy as a treatment option. It is based on the 2024 "Clinical Practice Guideline: Immunotherapy for Inhalant Allergy." This plain language summary is a companion publication to the full guideline, which provides greater detail for health care providers. Guidelines and their recommendations may not apply to every patient, but they can be used to find best practices and quality improvement opportunities.

[Update on asthma 2024 - what the ENT specialist needs to know]

The lifetime prevalence of 8.6% of asthma in Germany reflects the high medical and socioeconomic impact of the disease. Asthma treatment goals have changed during the last decades: from symptom control to symptom prevention, with highly effective, disease-modifying anti-asthmatic drugs (DMAADs) aiming at asthma remission. In order to achieve this goal, phenotyping of patients (including an evaluation of allergies and type 2 biomarkers) is crucial for personalized treatment. The identification and effective treatment of concomitant diseases, such as allergic rhinitis or chronic rhinosinusitis with nasal polyps (CRSwNP), plays a major role for successful treatment. This underlines the importance of interdisciplinary collaboration of otolaryngologists and respiratory physicians in the management of patients with asthma. This CME article informs the reader about current guidelines on the diagnosis and treatment of asthma, focusing on clinically relevant recommendations for ENT physicians.

Allergen immunotherapy combined with Notch pathway inhibitors improves HDM-induced allergic airway inflammation and inhibits ILC2 activation

Introduction

Group 2 innate lymphoid cells (ILC2s) play a crucial role in house dust mite (HDM)-induced allergic inflammation, and allergen immunotherapy (AIT) holds promise for treating the disease by reducing the frequency of ILC2s. Despite significant progress in AIT for allergic diseases, there remains a need to improve the control of allergic symptoms.

Methods

We investigated the synergistic effect of the Notch signaling pathway and subcutaneous immunotherapy (SCIT) in treating allergic airway inflammation in mice and their impact on the ratio of ILC2s in lung tissues. This was achieved by establishing the HDM-induced airway allergic disorders (HAAD) model and SCIT model. Additionally, we conducted in vitro investigations into the effect of the Notch signaling pathway on the secretory function of activated ILC2s using fluorescence-activated cell sorting. Furthermore, we explored the coactivation of the Notch signaling pathway with SCIT in vitro by sorting ILC2s from the lung tissues of mice after SCIT modeling.

Results

Previously, our group demonstrated that Notch signaling pathway inhibitors can reduce allergic airway inflammation in mice. Notch signaling induces lineage plasticity of mature ILC2s. In this study, we showed that AIT alleviates allergic airway inflammation and suppresses the frequency of ILC2s induced by HDM. Interestingly, AIT combined with a γ-secretase inhibitor (GSI), an inhibitor of the Notch signaling pathway, significantly inhibited the frequency of ILC2s, reduced airway inflammation, and suppressed Th2-type responses in a mouse model. Furthermore, lung ILC2s from HDM-challenged mice with or without AIT were treated with GSI in vitro, and we found that GSI dramatically reduced the secretion of type 2 inflammatory factors in ILC2s.

Discussion

These findings suggest that Notch signaling pathway inhibitors can be used as adjuvant therapy for AIT and may hold potential treatment value in the cooperative control of allergic airway inflammation during early AIT.

Prevention Is Better than Cure: Impact of Allergen Immunotherapy on the Progression of Airway Disease

Allergen immunotherapy is highly effective for seasonal pollinosis. Three years of treatment results in long-term efficacy. This disease modification is accompanied by downregulation of allergen-specific Th2 responses and the induction of persistent specific IgG- and IgA-associated IgE-blocking activity. In children with seasonal rhinitis, both subcutaneous and sublingual pollen immunotherapy have been shown to reduce the development of asthma symptoms and asthma medication requirements. House dust mite tablet allergen immunotherapy has been shown to be effective for perennial mite-driven rhinitis in adults and children and may suppress asthma exacerbations, whereas its long-term efficacy has yet to be explored. The success of primary prevention of peanut allergy in childhood by introduction of peanut into the diet during infancy provides a strong rationale to explore whether primary prevention of inhalant allergies and asthma may also be possible. House dust mite allergy is a major risk factor for developing asthma. Preliminary data in at-risk children suggest that sublingual house dust mite immunotherapy initiated during infancy could reduce the onset of multiple allergen sensitizations and prevent the development of asthma at age 6 years. This possibility should now be explored in an adequately powered, prospectively randomized controlled trial.

Maintenance Therapy for Children and Adolescents with Asthma: Guidelines and Recommendations from the Emilia-Romagna Asthma (ERA) Study Group

Asthma is the most frequent chronic disease of childhood, affecting up to 20% of children worldwide. The main guidelines on asthma maintenance therapy in pediatrics suggest different approaches and describe different stages of asthma to determine the most appropriate treatment. This project aims to summarize the most recent evidence regarding maintenance therapy for asthma in children and adolescents. A multidisciplinary panel of experts was asked clinical questions regarding the treatment of children and adolescents with asthma. Overall, 10 clinical questions were addressed, and the search strategy included accessing electronic databases and a manual search of gray literature published in the last 25 years. After data extraction and narrative synthesis of results, recommendations were developed using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) methodology. Results showed that the choice of medication depends on the severity of the child's asthma, phenotype, age, preference, and individual factors. In addition to medications, the identification of comorbidities and modifiable factors is crucial to obtaining good control. Asthma in children is heterogeneous, and its evolution varies over time. Since most recommendations for asthma management in childhood are extrapolated from clinical studies performed in adults, more clinical trials specifically designed for young children should be conducted.

Mechanism and clinical evidence of immunotherapy in allergic rhinitis

Allergic rhinitis is a common upper airway disease caused by hypersensitivity to various aeroallergens. It causes increased inflammation throughout the body and may be complicated by other otolaryngological pathologies such as chronic hyperplastic eosinophilic sinusitis, nasal polyposis, and serous otitis media. Allergic rhinitis is an IgE-mediated disease and immunotherapy can be a possible approach for patients to limit the use of antihistamines and corticosteroids. There is evidence that allergen immunotherapy can prevent the development of new sensitizations and reduce the risk of later development of asthma in patients with allergic rhinitis. However, some patients do not benefit from this approach and the efficacy of immunotherapy in reducing the severity and relapse of symptoms is still a matter of debate. This review highlights new aspects of allergic rhinitis with a particular focus on the impact of sexual dimorphism on the disease manifestation and efficacy to the allergen specific immunotherapy.

How can we improve our use of allergen immunotherapy as a treatment option for asthma and severe asthma?

INTRODUCTION

In patients suffering from allergic asthma, especially in the pediatric age-group, allergen immunotherapy (AIT) could be of benefit and has the potential of long-term disease modification.

AREAS COVERED

We reviewed the evidence for a beneficial effect of AIT in allergic asthma. A correct selection of the possible candidates for AIT is crucial. We define the comprehensive allergic asthma diagnosis: confirming asthma, confirming allergic sensitization and having symptoms on exposure to the relevant allergens.We analyze why the first trials on AIT for asthma were contradictory; we consider the results of systematic reviews and discuss the high degree of heterogeneity often found in meta-analysis. We assess recent, double-blind, placebo-controlled trials in sublingual AIT that provide robust evidence for a reduction in acute asthma exacerbations and a decrease in the use of inhaled corticosteroids. Further, we demonstrate how real-world trials and large pharmacy data-based analyses confirm these findings for SLIT and SCIT. Finally, we explore the option of AIT in severe asthma patients, once well-controlled on biologic therapy.

EXPERT OPINION

Clear indications for AIT in asthma guidelines would benefit allergic asthmatics. AIT is a therapeutic option in appropriately selected asthmatics. Three years treatment has the potential for long-term tolerance, with persisting benefits years after discontinuation.

Monitoring of molecular profiling of allergen-antibody responses in HDM-immunotherapy patients

Among the potential hazards of HDM immunotherapy (AIT) with HDM allergenic extracts is the possible initiation of de novosensitizations caused by a lack of complementarity between a given HDM vaccine's content and a patient's molecular sensitization profile. To investigate whether immunotherapy with HDM extracts affects changes in the profile of sensitizations to allergens contained in the extract and whether neosensitizations occur. Serum samples from patients with HDM allergies (N=63) who received 1 year of treatment with subcutaneous AIT were tested for allergen-specific IgE (sIgE) reactivity to 7 microarrayed HDM allergen molecules (Der p 1, 2,10,11,23; D far 1 and 2) with ImmunoCAP. The HDM non-AIT patients (N=22) who did not receive immunotherapy constituted the study's control group. The obtained data were analysed at baseline and after 6 and 12 months. In the HDM-AIT group, no neosensitizations after 6 and 12 months of immunotherapy were reported. Conversely, in the HDM non-AIT group, only neosensitizations to Der p 10 were observed. In the study group, sIgE levels against the HDM extract of D. pteronyssinus, D. farinae, rDer p 1, rDer p 2 and Der f 2 decreased after 12 months of AIT (p< .05). SIgE levels against Der f 1, Der p 10, 11 and 23 remained unchanged in the course of 12 months of immunotherapy. In patients with allergic rhinitis with or without concomitant HDM-induced asthma treated with HDM AIT for 12 months, no neosensitizations related to the examined HDM molecules were observed.

Immunotherapy: State-of-the-art review of therapies and theratypes

Through its disease-modifying potential, immunotherapy is the keystone to curing allergic diseases. Allergen immunotherapy, applied for more than a century, is currently supported by novel modalities such as mAb-based therapies or small molecules targeting the key nodes of the allergic inflammation network. In this review, a summary of the most significant advances in immunotherapy is presented, addressing not only novel approaches to stratifying patients but also major controlled clinical trials and real-world evidence that strengthen the role of immunotherapy in the treatment of allergies.

Diagnosis and management of allergy and respiratory disorders in sport: An EAACI task force position paper

Allergy and respiratory disorders are common in young athletic individuals. In the context of elite sport, it is essential to secure an accurate diagnosis in order to optimize health and performance. It is also important, however, to consider the potential impact or consequences of these disorders, in recreationally active individuals engaging in structured exercise and/or physical activity to maintain health and well-being across the lifespan. This EAACI Task Force was therefore established, to develop an up-to-date, research-informed position paper, detailing the optimal approach to the diagnosis and management of common exercise-related allergic and respiratory conditions. The recommendations are informed by a multidisciplinary panel of experts including allergists, pulmonologists, physiologists and sports physicians. The report is structured as a concise, practically focussed document, incorporating diagnostic and treatment algorithms, to provide a source of reference to aid clinical decision-making. Throughout, we signpost relevant learning resources to consolidate knowledge and understanding and conclude by highlighting future research priorities and unmet needs.

A Questionnaire Survey on the Prevalence and Parents' Perceptions of Respiratory Allergies in a 3- to 16-Year-Old Population in Wuhan, China

(1) Background: The prevalence of allergic rhinitis (AR) and asthma has increased rapidly in China. However, perceptions of respiratory allergies and barriers to their management have not attracted enough attention. (2) Objective: To investigate the prevalence of, parents’ perceptions of and their unmet needs for information concerning respiratory allergies in a 3- to 16-year-old children population. (3) Methods: A cross-sectional survey was conducted from June to July 2021 in three schools in Wuhan, China. A total of 1963 participants were recruited through cluster sampling for their parents to complete an online questionnaire regarding respiratory allergic symptoms. The diagnosis of respiratory allergies was based on self-reported symptoms and face-to-face physician evaluation. All the participants with respiratory allergies were asked to complete the Brief Illness Perception Questionnaire (B-IPQ), the Asthma Knowledge Questionnaire (AKQ) and a questionnaire regarding their unmet needs for disease management. (4) Results: The prevalence of respiratory allergies was 29.3% (576/1963) in the 3- to 16-year-old population, among whom AR accounted for 25.7%; asthma, 1.8% and AR-complicated asthma (AR&Asthma), 1.9%. The total B-IPQ score was 40.2 ± 10.9 in the participants with respiratory allergies, and there were no differences among the AR, asthma and AR&Asthma groups (all p > 0.05). The B-IPQ score correlated significantly with symptom onset time and a history of atopic dermatitis (p < 0.01). Nearly one fifth, 18.9%, of the participants with respiratory allergies never went to hospital for treatment, but those with higher B-IPQ scores were more likely to seek professional treatment (p < 0.001). The accuracy rates of AKQ were 72.5% in the participants with asthma and 76.7% in those without asthma (p = 0.147). Among the 576 participants with respiratory allergies, 568 (98.6%) had tried to obtain disease-management information from online platforms, and 55.5% (315/568) were dissatisfied with current platforms; the reasons included incomprehensive contents of illness (45.7%), lack of voice from leading experts (40.3%), too many advertisements (37.5%) and similar contents on different platforms (36.8%). (5) Conclusions: The prevalence of respiratory allergies is high in the 3- to 16-years old population in Wuhan, China. Yet the parents’ perceptions of respiratory allergies and knowledge of asthma are insufficient. It is crucial to increase parents’ awareness of the illness and facilitate their access to truly informative and professional platforms.

Roles of type 1 regulatory T (Tr1) cells in allergen-specific immunotherapy

Allergen-specific immunotherapy (AIT) is the only causative treatment for allergic diseases by modification of the immune response to allergens. A key feature of AIT is to induce immunotolerance to allergens by generating antigen-specific regulatory T (Treg) cells in allergic patients. Type 1 regulatory T (Tr1) cells and forkhead box protein 3 (Foxp3)-expressing Treg cells are well known among Treg cell subsets. Foxp3 was identified as a master transcription factor of Treg cells, and its expression is necessary for their suppressive activity. In contrast to Foxp3⁺ Treg cells, the master transcription factor of Tr1 cells has not been elucidated. Nevertheless, Tr1 cells are generally considered as a distinct subset of Treg cells induced in the periphery during antigen exposure in tolerogenic conditions and can produce large amounts of anti-inflammatory cytokines such as interleukin-10 and transforming growth factor-β, followed by down-regulation of the function of effector immune cells independently of Foxp3 expression. Since the discovery of Tr1 cells more than 20 years ago, research on Tr1 cells has expanded our understanding of the mechanism of AIT. Although the direct precursors and true identity of these cells continues to be disputed, we and others have demonstrated that Tr1 cells are induced in the periphery by AIT, and the induced cells are re-activated by antigens, followed by suppression of allergic symptoms. In this review, we discuss the immune mechanisms for the induction of Tr1 cells by AIT and the immune-suppressive roles of Tr1 cells in AIT.

Therapeutic Effect of Renifolin F on Airway Allergy in an Ovalbumin-Induced Asthma Mouse Model In Vivo

Renifolin F is a prenylated chalcone isolated from Shuteria involucrata, a traditional minority ethnic medicine used to treat the respiratory diseases and asthma. Based on the effects of the original medicine plant, we established an in vivo mouse model of allergic asthma using ovalbumin (OVA) as an inducer to evaluate the therapeutic effects of Renifolin F. In the research, mice were sensitized and challenged with OVA to establish an allergic asthma model to evaluate the effects of Renifolin F on allergic asthma. The airway hyper-reactivity (AHR) to methacholine, cytokine levels, ILC2s quantity and mircoRNA-155 expression were assessed. We discovered that Renifolin F attenuated AHR and airway inflammation in the OVA-induced asthmatic mouse model by inhibiting the regulation of ILC2s in the lung, thereby, reducing the upstream inflammatory cytokines IL-25, IL-33 and TSLP; the downstream inflammatory cytokines IL-4, IL-5, IL-9 and IL-13 of ILC2s; and the co-stimulatory factors IL-2 and IL-7; as well as the expression of microRNA-155 in the lung. The findings suggest a therapeutic potential of Renifolin F on OVA-induced airway inflammation.