Five-year follow-up on the PAT study: specific immunotherapy and long-term prevention of asthma in children

Changes of Clinical Practice Patterns of Allergen Immunotherapy in Korea

This study aimed to identify recent changes of AIT treatment behaviors in real-world clinical practice using a questionnaire survey in Korea. The questionnaire on AIT prescriptions and practical experiences was distributed to all members of the Korean Academy of Asthma Allergy and Clinical Immunology in June 2022. The responses were analyzed and compared with the results from 2009 and 2017. In total, 115 responses (10.1%) were collected; 58 (50.4%) from internal medicine, 34 (29.6%) from pediatricians, and 21 (18.3%) from otolaryngologists. The prescription rate for subcutaneous immunotherapy (SCIT) was 53.8%, showing a decrease from those in 2009 and 2017; however, that for sublingual immunotherapy (SLIT) increased steadily, reaching 17.9% in 2009, 40.3% in 2017, and 46.2% in 2022. The prescription rates for asthma and atopic dermatitis increased by 4.6% and 7.9%, respectively. The most frequently prescribed allergens for SCIT in 2022 were house dust mites (32.9%), pollen (30.6%), and animal dander (28.2%), with the rate for animal dander showing a significant increase from 10.3% in 2009. Most physicians (93%) used mixed allergens for SCIT, with 42.8% using a combination of 5 or more allergens. Fifty-eight (67.4%) respondents reported cases of anaphylaxis during SCIT and 36.2% reported systemic adverse reactions during SLIT. In conclusion, SLIT prescriptions, AIT for asthma and atopic dermatitis, and AIT with animal dander increased significantly from 2009 to 2022. Serial surveys of AIT practices are helpful in identifying the changes of real-world clinical practice of AIT.

Asthma

Asthma is one of the most common respiratory disorders in Canada, however, many Canadians with asthma remain poorly controlled. In most patients, control can be achieved through appropriate therapy, including: inhaled corticosteroids (ICS), combination ICS/long-acting beta2-agonists (LABA), "triple therapy" with ICS/LABA/long-acting muscarinic receptor antagonist (LAMA), and biologic therapies. The medical management of severe asthma, in particular, has changed dramatically with the incorporation of biologics in asthma treatment plans. Allergen-specific immunotherapy represents a potentially disease-modifying therapy for many patients with asthma; it must only be prescribed by physicians with appropriate training in allergy. Other essential components of asthma management include: regular monitoring of asthma control and risk of exacerbations; patient education and written asthma action plans; assessing barriers to treatment and adherence to therapy; adequate management of comorbidities (e.g., allergic rhinitis) and reviewing inhaler device technique. This article provides a review of current literature and guidelines for the appropriate diagnosis and management of asthma in adults and children.

Allergen Immunotherapy for the Prevention and Treatment of Asthma

Allergic asthma is the predominant phenotype among asthmatics. Although conventional pharmacotherapy is a central component in the management of asthma, it does not enable control of asthma symptoms in all patients. In recent decades, some uncontrolled asthmatic patients, especially those with allergic asthma, have benefited from biological therapies. However, biologics do not address all the unmet needs left by conventional pharmacotherapy. Furthermore, it is noteworthy that neither conventional pharmacotherapy nor biological therapies have disease-modifying properties. In this context, allergen immunotherapy (AIT) represents an indispensable component of the therapeutic arsenal against allergic asthma, due to its disease-modifying immunological effects. In this review article, funded by an AIT manufacturer, we find clinical trials support AIT as the only treatment option able both to improve allergic asthma symptoms and to prevent the onset and worsening of the condition. For patients with severe asthma or other safety concerns, the combination of AIT and biologics offers very promising new treatment modalities for the management of allergic asthma. Trial Registration: clinicaltrials.gov identifier: NCT06027073.

Identifying super-responders: A review of the road to asthma remission

Asthma is a chronic respiratory disease marked by heterogeneity and variable clinical outcomes. Recent therapeutic advances have highlighted patients achieving optimal outcomes, termed "remission" or "super-response." This review evaluates the various definitions of these terms and explores how disease burden impedes the attainment of remission. We assessed multiple studies, including a recent systematic review and meta-analysis, on biologic treatments for asthma remission. Our review highlights that type 2 inflammation may be the strongest predictor of biologic response. Key comorbidities (eg, obesity and mood disorders) and behavioral factors (eg, poor adherence, improper inhalation technique, and smoking) were identified as dominant traits limiting remission. In addition, asthma burden and longer disease duration significantly restrict the potential for remission in patients with severe asthma under the current treatment paradigm. We review the potential for a "predict-and-prevent" approach, which focuses on early identification of high-risk patients with type 2 inflammation and aggressive treatment to improve long-term asthma outcomes. In conclusion, this scoping review highlights the following unmet needs in asthma remission: (1) a harmonized global definition, with better defined lung function parameters; (2) integration of nonbiologic therapies into remission strategies; and (3) a clinical trial of early biologic intervention in patients with remission-prone, very type 2-high, moderately severe asthma with clinical remission as a predefined primary end point.

Allergen immunotherapy

Allergen immunotherapy (AIT) is a potentially disease-modifying therapy that is effective for the treatment of allergic rhinitis/conjunctivitis, allergic asthma and stinging insect hypersensitivity. The decision to proceed with AIT should be made on a case-by-case basis, based on a comprehensive evaluation of the patient, allergy testing and a thorough discussion with the patient about treatment goals, risks vs. benefits, and long-term commitment to the treatment plan. For those with allergic rhinitis and/or asthma, it is also important to consider individual patient factors, such as the degree to which symptoms can be reduced by avoidance measures and pharmacological therapy, the amount and type of medication required to control symptoms, the adverse effects of pharmacological treatment, and patient preferences.Since AIT is associated with a risk of anaphylaxis, it should only be prescribed by physicians who are adequately trained in the treatment of allergic conditions. Furthermore, for subcutaneous therapy, injections must be given under medical supervision in clinics that are equipped to manage anaphylaxis. In this article, we review the indications and contraindications, patient selection criteria, and details regarding the administration, safety and efficacy of AIT for allergens other than foods. Immunotherapy for food allergy will be discussed in the Oral Immunotherapy article in this supplement.

A novel dose-adjustment protocol for interrupted subcutaneous immunotherapy in children with allergic rhinitis

Aim: To assess the effectiveness and safety of a new protocol for adjusting doses during interrupted subcutaneous immunotherapy maintenance, exceeding an 8-week interval, with mite allergen injections in children with allergic rhinitis.Patients & methods: 194 children with allergic rhinitis who underwent subcutaneous immunotherapy and experienced interruptions lasting more than 8 weeks during maintenance were enrolled. Following the adoption of a novel dose-adjustment protocol, a real-world study was conducted.Results: After 3 years of subcutaneous immunotherapy, the novel group exhibited a significant reduction in allergy symptoms compared with baseline. Systemic reactions related to the novel protocol did not significantly increase.Conclusion: The novel protocol was deemed safe and effective, offering advantages of time savings and reduced burdens.

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.

The effectiveness of pollen allergen immunotherapy on allergic rhinitis over 18 years: A national cohort study in Denmark

BACKGROUND

Because long-term effectiveness of pollen allergen immune therapy (AIT) for allergic rhinitis (AR) is not well-described, we studied effectiveness over 18 years in Denmark.

METHODS

A register-based cohort study using data on filled prescriptions, 1995-2016, Denmark. In a cohort of 1.1 million intranasal corticosteroid inhaler users (proxy for AR), we matched users treated with grass, birch or mugwort AIT 1:2 with non-treated users on baseline year and 24 characteristics in the 3 years prior to baseline. The primary outcome was the odds ratio (OR) of using anti-allergic nasal inhaler during the pollen season in the treated versus non-treated group by years since baseline.

RESULTS

Among 7760 AR patients treated with pollen AIT, the OR of using nasal inhaler 0-5 years after baseline was reduced when compared with 15,520 non-treated AR individuals (0-2 years, OR 0.84 (0.81-0.88); 3-5 years, OR 0.88 (0.84-0.92)), but was close to unity or higher thereafter (6-9 years, OR 1.03 (0.97-1.08); 10-18 years, OR 1.18 (1.11-1.26)). In post hoc analyses, results were more consistent for those who already had 3 of 3 baseline years of use, and in patients using nasal inhaler in the latest pollen season (0-2 years, OR 0.76 (0.72-0.79); 3-5 years OR 0.86 (0.81-0.93); 6-9 years, OR 0.94 (0.87-1.02); 10-18 years, OR 0.94 (0.86-1.04)) as opposed to no such use.

CONCLUSIONS

Patients treated with pollen AIT in routine care to a higher degree stopped using anti-allergic nasal inhaler 0-5 years after starting the standard 3 years of therapy, and not beyond 5 years. Post hoc analyses suggested effectiveness was more consistent among patients with persistent AR.

Pre-asthma: a useful concept for prevention and disease-modification? A EUFOREA paper. Part 1-allergic asthma

Asthma, which affects some 300 million people worldwide and caused 455,000 deaths in 2019, is a significant burden to suffers and to society. It is the most common chronic disease in children and represents one of the major causes for years lived with disability. Significant efforts are made by organizations such as WHO in improving the diagnosis, treatment and monitoring of asthma. However asthma prevention has been less studied. Currently there is a concept of pre- diabetes which allows a reduction in full blown diabetes if diet and exercise are undertaken. Similar predictive states are found in Alzheimer's and Parkinson's diseases. In this paper we explore the possibilities for asthma prevention, both at population level and also investigate the possibility of defining a state of pre-asthma, in which intensive treatment could reduce progression to asthma. Since asthma is a heterogeneous condition, this paper is concerned with allergic asthma. A subsequent one will deal with late onset eosinophilic asthma.

The pharmacotherapeutic management of allergic rhinitis in people with asthma

INTRODUCTION

Up to 90% of asthmatic patients have comorbid allergic rhinitis (AR). Although appropriate therapy of AR can improve asthma symptoms and management, AR is often underdiagnosed and under-treated in asthmatics.A non-systematic literature research was conducted on AR as a comorbidity and risk factor of asthma. Latest international publications in medical databases, international guidelines, and the Internet were reviewed.

AREAS COVERED

Based on the conducted literature research there is proved evidence of the necessity of diagnosis and treatment of AR in patients with asthma because it affects health care utilization. Therefore, it is recommended in national and global guidelines.

EXPERT OPINION

AR increases the risk of asthma development and contributes to the severity of an existing asthma. Early treatment of AR with drugs as intranasal steroids, antihistamines, leukotriene receptor antagonists, and especially allergen-specific immunotherapy can reduce the risk of asthma development and the concomitant medication use in addition to severity of symptoms in AR and asthma.

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.

A novel dose-adjustment protocol for interrupted subcutaneous immunotherapy for allergic rhinitis

Background: This study aimed to develop a novel dose strategy for subcutaneous immunotherapy to reduce medical waste and financial burdens for patients who are required to restart subcutaneous immunotherapy. Patients & methods: A prospective, nonrandomized concurrent controlled trial was performed to assess the safety and advantages of the novel dose-adjustment protocol compared with the conventional one. 76 subjects were grouped to receive novel or conventional dose-adjustment protocols. Results: The injections, visits and time needed to reach the pre-established dose with the novel regimen were decreased. Furthermore, there were no differences in side reactions between the two groups. Conclusion: The novel protocol seemed safe and well tolerated, offering the advantages of time efficiency and reduced healthcare costs.

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.

Can development of asthma and bronchial hyperreactivity be reduced by subcutaneous immunotherapy in adult patients with allergic rhinitis?

BACKGROUND

Allergic rhinitis can be associated with bronchial hyperreactivity (BHR) and create an increased risk for allergic asthma development. We aimed to investigate the effects of subcutaneous immunotherapy (SCIT) on BHR and asthma development in adult patients with allergic rhinitis.

METHODS

The retrospective case-control study was carried out between November 2018 and May 2019 in Süreyyapaşa Chest Diseases and Thoracic Surgery Training and Research Hospital. In this study, data was recorded for patients with a mite and/or grasses/cereals pollen allergy who were tested for BHR before planned SCIT, and who had allergic rhinitis, with or without asthma. The SCIT group was selected as those who received SCIT for at least one year. The control group was selected from those who were scheduled to receive SCIT but were waived and still receiving medication. Symptom scores, prick test results, PC20 levels (methacholine challenge that is a provocative concentration causing a 20% fall in FEV1), and the presence of asthma were recorded and compared with data from at least one year after treatment.

RESULTS

A total of sixty-eight subjects (22 males, 46 females; mean age 40.54 ± 12.27 years; SCIT: 40, Control: 28) were enrolled.Although the changes in log PC20 levels were not statistically significant in both SCIT and control groups after an average of 30-35 months of treatment, it was found to be significant in favor of the SCIT group when two groups were compared in terms of the change in log PC20 (p = 0.026). The development and improvement of asthma were not significantly different between the SCIT and control group but tended to increase in the control group. The percentage of patients with progressed/BHR was significantly higher in the controls (70.6% vs. 38.1%, p = 0.046).

DISCUSSION

In our real life study we have demonstrated the preventative effect of SCIT on BHR, but not on asthma developmen.

KAAACI Allergic Rhinitis Guidelines: Part 2. Update in Non-pharmacological Management

Allergic rhinitis is the most common chronic disease worldwide. Various upper airway symptoms lower quality of life, and due to the recurrent symptoms, multiple treatments are usually attempted rather than one definitive treatment. There are alternatives to medical (medication-based) and non-medical treatments. A guideline is needed to understand allergic rhinitis and develop an appropriate treatment plan. We have developed guidelines for medical treatment based on previous reports. The current guidelines herein are associated with the "KAAACI Evidence-Based Guidelines for Allergic Rhinitis in Korea, Part 1: Update in pharmacotherapy" in which we aimed to provide evidence-based recommendations for the medical treatment of allergic rhinitis. Part 2 focuses on non-pharmacological management, including allergen-specific immunotherapy, subcutaneous or sublingual immunotherapy, nasal saline irrigation, environmental management strategies, companion animal management, and nasal turbinate surgery. The evidence to support the treatment efficacy, safety, and selection has been systematically reviewed. However, larger controlled studies are needed to elevate the level of evidence to select rational non-medical therapeutic options for patients with allergic rhinitis.

Subcutaneous allergen immunotherapy in the treatment of allergic respiratory disease

Subcutaneous immunotherapy is recognized as a cornerstone in the management of allergic respiratory disease in patients who are properly characterized with allergy and with allergic rhinoconjunctivis and/or well-controlled asthma, and who are willing to adhere to the rigorous treatment program. A key tenet is that it affords the opportunity to effect long-term clinical remission through its disease-modifying properties. Furthermore, it has the potential to prevent the progression of allergic rhinitis to asthma, prevent new allergen sensitivities, and improve a patient's quality of life.

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

BACKGROUND

Allergen immunotherapy (AIT) is a disease-modifying treatment for IgE-mediated diseases. Randomized controlled trials (RCTs) support AIT's potential role in asthma prevention but evidence from non-randomized studies of interventions (NRSI) and longitudinal observational studies has been poorly addressed. Therefore, we aimed to conduct a systematic review and meta-analysis to assess clinical data from all study types to evaluate quantitatively the preventive role of AIT in asthma onset.

METHODS

We search three databases. Studies were screened, selected and evaluated for quality using risk-of-bias (ROB) tools. Data were descriptively summarized and meta-analysed using random effects. We performed a sensitivity, influence and subgroup analyses. Publication bias and heterogeneity were assessed.

RESULTS

From the 4549 identified studies, 24 (12 RCTs and 12 NRSI) were included in the qualitative synthesis and 18 underwent meta-analysis. One study was at low ROB, seven had moderate ROB, and 15 were proven of high ROB. Random-effects analysis showed a significant decrease in the risk of developing asthma following AIT by 25% (RR, 95% CI: 0.75, 0.64-0.88). This effect was not significant in the sensitivity analysis. Publication bias raised concerns, together with the moderate heterogeneity between studies (I²  = 58%). Subgroup analysis showed a remarkable preventive effect of AIT in children (RR, 95% CI: 0.71, 0.53-0.96), when completing 3 years of therapy (RR, 95% CI: 0.64, 0.47-0.88), and in mono-sensitized patients (RR, 95% CI: 0.49, 0.39-0.61).

CONCLUSIONS

Our findings support a possible preventive effect of AIT in asthma onset and suggest an enhanced effect when administered in children, mono-sensitized, and for at least 3 years, independently of allergen type.

Does allergen immunotherapy for allergic rhinitis prevent asthma?

Asthma and allergic rhinitis (AR) have overlapping clinical and pathologic features, sustained by an underlying T helper 2 bias, resulting in airway inflammation that extends from the nose to the lung. Children who are monosensitized often develop polysensitization over time, and they are at high risk of developing asthma. The effect of allergen immunotherapy (AIT) is allergen specific, resulting in symptom improvement and reduction in medication requirement. It is the only known treatment that alters the natural history of allergic disease and induces long-term remission. A bystander or allergen-nonspecific effect of AIT has also been proposed-that AIT to 1 allergen might reduce the risk of development of sensitization to other allergens. Furthermore, several observational studies and clinical trials, in seasonal (pollen) and perennial (house dust mite) AR, have investigated a protective effect of AIT to prevent asthma. The overall evidence favors an asthma preventive effect of AIT in AR to grass and birch tree pollen. Fewer studies have investigated the use of AIT in children with perennial AR due to house dust mite allergy to prevent asthma, and the results are less convincing. The use of AIT to reduce the risk of progression to asthma, in children with AR, potentially has high impact, and it will make AIT more attractive and cost-effective. However, most studies have been of small sample size or of poor design, using different allergens and AIT methodology, making it challenging to draw firm conclusions. There is a need to do adequately powered studies with optimal design and assess cost-effectiveness of this strategy.

Allergen immunotherapy in treating allergic eosinophilic asthma

Currently, the approach to a patient with asthma is in accordance with personalized medicine wherein the decision on the treatment pathway is based on the type of asthmatic inflammation and other comorbidities that accompany asthma. For an allergic asthma patient, allergen immunotherapy (AIT), which has a disease-modifying effect and the potential to prevent further progression of allergic symptoms, is one of the treatment modalities. It is an effective treatment that, unlike pharmacotherapy, modifies the course of allergic respiratory diseases and induces allergen specific immune tolerance that persists for up to several years after treatment cessation. Therapeutic allergens of high quality, efficacy, and safety according to European regulatory authorities are an integral part of the treatment of respiratory allergies. It is a safe treatment option which still remains the only causal immuno¬modulatory therapy for allergic eosinophilic asthma.

A study of Spirometric parameters in non asthmatic allergic rhinitis

Introduction

Allergic rhinitis (AR) is a common IgE -mediated inflammatory condition characterised by sneezing, nasal congestion, itching and rhinorrhoea. Nasal allergy is a strong risk factor for the onset of asthma in adults. Bronchial hyper-responsiveness (BHR) is a distinct feature of pathophysiology in asthma. Spirometric parameters like Forced Expiratory Volume in first second [FEV1] and Forced Expiratory Flow [FEF _25-75%] are known to be impaired in patients with allergic rhinitis. We studied these parameters in subjects of AR who have never experienced any chest symptoms. It is well known that, subjects with allergic rhinitis are at greater risk of developing overt bronchial asthma in future.

Methods

All patients presented with symptoms of allergic rhinitis without history of bronchial asthma were included. Patients those who were clinically diagnosed with allergic rhinitis were evaluated with absolute eosinophilic count, serum IgE and Spirometric assessment. In spirometry, post bronchodilator FEV1 reversibility and post bronchodilator FEF _25-75% values were used to assess lower airway abnormalities.

Results

Among 61 subjects, 32 were males and 29 were females. The maximum numbers [28] of patients were in 21-35 age group. Absolute eosinophil count was elevated in 38% of patients. 33% of patients showed elevated IgE values above 1000. 43% of patients showed FEV1 reversibility which is a sign of Bronchial hyperreactivity. 5% of patients showed impaired post bronchodilator FEF _25-75% which indicates presence of small airway disease. There was significant correlation between FEV1 reversibility and elevated IgE.

Conclusion

Impaired spirometric parameters indicate coexistence of bronchial impairment and hence predisposition to progression from allergic rhinitis alone to overt asthma in future. Thus careful evaluation of lower airway has to be done to rule out coexisting subclinical asthma.

Allergic Rhinitis: What Do We Know About Allergen-Specific Immunotherapy?

Allergic rhinitis (AR) is an IgE-mediated disease that is characterized by Th2 joint inflammation. Allergen-specific immunotherapy (AIT) is indicated for AR when symptoms remain uncontrolled despite medication and allergen avoidance. AIT is considered to have been effective if it alleviated allergic symptoms, decreased medication use, improved the quality of life even after treatment cessation, and prevented the progression of AR to asthma and the onset of new sensitization. AIT can be administered subcutaneously or sublingually, and novel routes are still being developed, such as intra-lymphatically and epicutaneously. AIT aims at inducing allergen tolerance through modification of innate and adaptive immunologic responses. The main mechanism of AIT is control of type 2 inflammatory cells through induction of various functional regulatory cells such as regulatory T cells (Tregs), follicular T cells (Tfr), B cells (Bregs), dendritic cells (DCregs), innate lymphoid cells (IL-10⁺ ILCs), and natural killer cells (NKregs). However, AIT has a number of disadvantages: the long treatment period required to achieve greater efficacy, high cost, systemic allergic reactions, and the absence of a biomarker for predicting treatment responders. Currently, adjunctive therapies, vaccine adjuvants, and novel vaccine technologies are being studied to overcome the problems associated with AIT. This review presents an updated overview of AIT, with a special focus on AR.

Allergen Immunotherapy in Pediatric Respiratory Allergy

Purpose of Review

Atopic diseases such as asthma and allergic rhinitis are highly prevalent in children. Common triggers include tree and grass pollens, house dust mites, molds, and animal dander. These diseases are most often treated symptomatically; however, many patients show partial or poor response and require long-term medication use. Allergen immunotherapy (AIT) stands as the only treatment modality that can alter the underlying disease process and potentially offer a cure. In this review article, we discuss the merits of AIT with particular emphasis on its efficacy and safety in pediatric patients. We also discuss the challenges for AIT implementation and present an overview of current research that aims at improving its applicability for the treatment of allergic diseases.

Recent Findings

Subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) are both safe and efficacious treatment options in children with allergic rhinitis and allergic asthma. Additionally, AIT has efficacy in preventing the development of asthma in children. Although there are clear advantages with AIT, there are challenges to overcome to optimize treatment. Solutions include improved diagnostics with pre-treatment biomarkers and molecular multiplex assays, biomarkers for prediction of response (e.g., basophil activation markers), improved allergen immunogenicity with the use of recombinant AIT, adjuvants, and allergoids, and lastly improved safety with the concurrent use of omalizumab.

Summary

AIT has shown safety and efficacy in major clinical trials for the treatment of allergic rhinitis and allergic asthma in children. AIT provides a curative treatment option for atopic disorders and should be considered in children with allergic rhinitis and allergic asthma. There are many continued advances being made in the field of allergy to further improve the safety and efficacy profile and shorten the duration of AIT treatment.

Preventive Effect of Allergen Immunotherapy on Asthma and New Sensitizations

Allergen immunotherapy (AIT) is a disease-modifying treatment for some IgE-mediated allergic diseases with the potential to have important preventive effects. Children with allergic rhinitis have a high risk of developing asthma, and treating allergic rhinitis with AIT may interfere with disease progression and prevent onset of asthma. Although the evidence is limited due to relatively few and heterogeneous studies, data nevertheless suggest that AIT has a preventive effect on development of asthma especially in children with rhinitis due to grass pollen allergy. AIT may also affect the development of new sensitizations. Both the degree of sensitization and the specific sensitization pattern may influence future disease severity and development of comorbidities. Hitherto, the indication for AIT for prevention of development of asthma in grass/birch pollen allergic children has been the same as for treatment of allergic rhinitis. Probably, AIT should be applied in the early stage of the allergic disease to have the greatest preventive effect on disease progression. Consequently, in the future, the potential preventive effects should influence the timing of initiating AIT. The window of opportunity to prevent asthma may primarily exist in young children with mild symptoms and a low degree of sensitization.

Multiple Allergen Simultaneous Test-Immunoblot Assay for Immunoglobulin E Detection in Patients with Isolated Allergic Conjunctivitis

We aimed to investigate the immunoglobulin E (IgE) detection rate and allergen patterns in patients with isolated allergic conjunctivitis using the multiple allergen simultaneous test (MAST)-immunoblot assay. A total of 120 patients with allergic conjunctivitis and no associated rhinitis, asthma, or dermatitis underwent the MAST-immunoblot assay to measure serum total IgE (TIgE) and serum specific IgE (SIgE) against 57 allergens. Patients were classified into subgroups based on the season when the eye symptoms were exacerbated, and TIgE and SIgE positivity. Differences between sex and age groups were also analyzed. Of the 120 patients, 57.5% (69 patients) and 69.2% (83 patients) were positive for TIgE (≥100 IU/mL) and SIgE (≥0.7 IU/mL), respectively. The allergens that most frequently triggered sensitization in the study population were Dermatophagoides farinae, Dermatophagoides pteronyssinus, Tyrophagus putrescentiae, Alternaria, and house dust. House dust mites, such as D. farinae and D. pteronyssinus, showed the highest detection rates regardless of the season. Men had a higher positive rate for TIgE than women, whereas a higher rate of sensitization, detected as SIgE positivity, was seen in younger patients. In conclusion, MAST-immunoblot assay can detect sensitizing allergens in patients with isolated allergic conjunctivitis.

Recent Advances in Allergen-Specific Immunotherapy as Treatment for Allergic Asthma: A Practical Overview

The Global Initiative for Asthma Report updated in 2019 stated that potential benefits of allergen immunotherapy (AIT), compared to pharmacological and avoidance options, must be weighed against the risk of adverse effects and the inconvenience and cost of the prolonged course of therapy in asthma. Thus, with the aim of clarifying some aspects with regard to the possible use of AIT in allergic asthma treatment armamentarium, a group of expert allergists from the Spanish Allergy and Clinical Immunology Scientific Society (SEAIC), particularly from the Immunotherapy and Asthma Interest Groups developed a frequently asked questions in clinical practice. This document updates relevant topics on the use of AIT in asthma and could facilitate physician clinical decisions and improve health outcomes for individual patients.

A randomized trial of subcutaneous allergy immunotherapy in inner-city children with asthma less than 4 years of age

BACKGROUND

Allergic sensitization to environmental allergens in the first years of life is a strong predictor of asthma morbidity in children. Allergy immunotherapy can improve asthma and allergy outcomes, but its efficacy in inner-city, atopic children of less than 4 years of age with recurrent wheezing has not yet been established.

OBJECTIVE

To determine whether subcutaneous allergy immunotherapy improves asthma in a population of US inner-city children when started at less than 4 years of age.

METHODS

In a randomized controlled, open-label phase I-II single-center trial in the Bronx, New York, 58 children with recurrent wheezing or physician-diagnosed asthma were randomized to receive asthma standard of care treatment with or without a 3-year course of multiple allergen subcutaneous immunotherapy.

RESULTS

A total of 23 children in the control group and 27 children in the immunotherapy group began the study. A total of 20 of 27 children commencing immunotherapy completed at least 2 years of immunotherapy. There was no difference in asthma medication and symptom scores between the treatment or control groups over time. Similarly, naso-ocular symptoms and allergy medication use were similar in both groups over time. Nevertheless, asthma-related quality of life improved in the immunotherapy group compared with the control group (P = .03).

CONCLUSION

With the exception of asthma-related quality of life, allergy immunotherapy was ineffective in improving asthma outcomes in this population of inner-city children of less than 4 years of age. These findings suggest that the effects of allergy immunotherapy depend on population-specific factors and highlight the importance of precise predictors of immunotherapy efficacy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01028560.

Past, present, and future of allergen immunotherapy vaccines

Allergen-specific immunotherapy (AIT) is an allergen-specific form of treatment for patients suffering from immunoglobulin E (IgE)-associated allergy; the most common and important immunologically mediated hypersensitivity disease. AIT is based on the administration of the disease-causing allergen with the goal to induce a protective immunity consisting of allergen-specific blocking IgG antibodies and alterations of the cellular immune response so that the patient can tolerate allergen contact. Major advantages of AIT over all other existing treatments for allergy are that AIT induces a long-lasting protection and prevents the progression of disease to severe manifestations. AIT is cost effective because it uses the patient´s own immune system for protection and potentially can be used as a preventive treatment. However, broad application of AIT is limited by mainly technical issues such as the quality of allergen preparations and the risk of inducing side effects which results in extremely cumbersome treatment schedules reducing patient´s compliance. In this article we review progress in AIT made from its beginning and provide an overview of the state of the art, the needs for further development, and possible technical solutions available through molecular allergology. Finally, we consider visions for AIT development towards prophylactic application.

Safety, Efficacy, and Preventive Role of Subcutaneous and Sublingual Allergen Immunotherapy for the Treatment of Pediatric Asthma

Allergen-specific immunotherapy is currently the only treatment with the potential to modify and prevent progression of allergic asthma in children. In clinical practice, it is available in two forms: subcutaneous immunotherapy and sublingual immunotherapy. Trials and meta-analyses showed both the safety and the short- and long-term benefits of allergen-specific immunotherapy in asthmatic children. However, its use and role in asthma remains controversial, since studies are largely heterogeneous. This is mainly due to the lack of consensus on the optimal primary outcome to be considered for clinical trials evaluating the efficacy of allergen-specific immunotherapy in asthma. Therefore, well-conducted researchis needed using standardized and validated tools to evaluate key outcomes in asthmatic children.

Allergenspezifische Immuntherapie (AIT) in Österreich

Die allergenspezifische Immuntherapie (AIT) ist die einzige ursächliche Behandlung der IgE-vermittelten, Typ‑1 allergischen Erkrankungen allergischer Rhinokonjunktivitis, allergischem Asthma bronchiale und anaphylaktischen Reaktionen auf Insektengift („venom immunotherapy“, VIT). Sie wird entweder subkutan (SCIT) oder sublingual (SLIT) über 3 Jahre verbreicht. Da die deutschsprachigen Leitlinien zur AIT sowohl gegen inhalative Allergien als auch die VIT gegen Bienen‑/Wespenallergie abgelaufen und Ende 2020 im Status der Überarbeitung sind, werden sich die Empfehlungen stattdessen auf die europäischen EAACI-Leitlinien von 2018 beziehen.

Allergen Immunotherapy in children with respiratory allergic diseases

Allergen immunotherapy (AIT) is a well-established treatment for allergic respiratory diseases. It represents a cornerstone in the clinical management of allergic children since it is the only curative option to date able to modify the natural history of Ig-E mediated allergic diseases. Through a well-defined immunologic mechanism, AIT promotes regulatory T cells and cuts down the immune response induced by allergens. According to current guidelines based on up-to-date evidence, AIT should be offered to children with moderate-severe allergic rhinitis and/or controlled asthma starting from 5 years of age, further to an adequate risk-benefit assessment which includes patient's adherence to the treatment and a proper selection of the right product. Younger age and mild disease could be considered based on an individual evaluation. Both subcutaneous (SCIT) and sublingual (SLIT) routes of administration have a good efficacy and safety profile with safer outcomes for SLIT compared to SCIT. Only standardized products with documented evidence of clinical efficacy should be used. Although AIT is used worldwide, there are still gaps and limitations, including the lack of reliable biomarkers predictive of the clinical outcome. Novel adjuvants are currently under investigations to boost the strength and efficiency of the immune response, as well as new formulations with better efficacy and better patient's adherence to the treatment. Herein, we aim to provide an overview of current key evidence with major regard to clinical practice as well as knowledge gaps and future research needs in the context of AIT in children with respiratory allergic diseases.

Recombinant allergens for immunotherapy: state of the art

PURPOSE OF REVIEW

More than 30 years ago, the first molecular structures of allergens were elucidated and defined recombinant allergens became available. We review the state of the art regarding molecular AIT with the goal to understand why progress in this field has been slow, although there is huge potential for treatment and allergen-specific prevention.

RECENT FINDINGS

On the basis of allergen structures, several AIT strategies have been developed and were advanced into clinical evaluation. In clinical AIT trials, promising results were obtained with recombinant and synthetic allergen derivatives inducing allergen-specific IgG antibodies, which interfered with allergen recognition by IgE whereas clinical efficacy could not yet be demonstrated for approaches targeting only allergen-specific T-cell responses. Available data suggest that molecular AIT strategies have many advantages over allergen extract-based AIT.

SUMMARY

Clinical studies indicate that recombinant allergen-based AIT vaccines, which are superior to existing allergen extract-based AIT can be developed for respiratory, food and venom allergy. Allergen-specific preventive strategies based on recombinant allergen-based vaccine approaches and induction of T-cell tolerance are on the horizon and hold promise that allergy can be prevented. However, progress is limited by lack of resources needed for clinical studies, which are necessary for the development of these innovative strategies.

New perspectives in allergen specific immunotherapy driven by big trials with house dust mite sublingual SQ® tablets

House-dust mites (HDM) allergy is the prevailing condition in subjects allergic to inhalants. Clinical studies with HDM extracts—either subcutaneous (SCIT) or sublingual (SLIT) have long been characterized by small sample size, varying allergen doses, and poorly defined endpoints assessing disease severity. In the last decade, well-designed, randomized, controlled studies recruiting thousands of patients have been conducted with newly developed HDM sublingual tablets (SQ^®-HDM tablets). This drug is easily dispersible in the oral cavity due to the patented Zydis^® technology and its allergen composition is balanced in terms of group I and group II major mite allergen content, reflecting the equal contribution of the two components to HDM sensitization. HDM is the most common allergen associated with asthma. Clinical efficacy of the SQ^® HDM SLIT-tablet in HDM allergic asthma has been evaluated in randomized, double-blind, placebo-controlled trials. Both endpoints related to “present” asthma control (inhaled corticosteroid—ICS) as well as endpoints related to “future” asthma control (occurrence of asthma exacerbations) were included in these studies, in agreement with GINA (Global Initiative for Asthma) guidelines. Based on the positive results of these studies, SQ^®-HDM SLIT-tablets were approved Europe-wide as registered drug for treating moderate-to-severe allergic rhinitis with or without allergic asthma and not well controlled HDM allergic asthma, associated with allergic rhinitis of any severity. GINA guidelines in 2017 included SLIT-tablet-based immunotherapy as an “add-on” treatment for asthmatic patients sensitized to HDM; indeed, allergen immunotherapy (AIT) is considered to be a complementary treatment option that targets the immunological of allergic diseases, representing the only treatment potentially disease-modifier or, at least, with a long-term efficacy. The availability of a safe, standardized, registered treatment for HDM respiratory allergies is pivotal in the immunotherapy field, pushing it out of a century-long limbo of amatorial interest towards the full dignity deserved by the only casual treatment of respiratory allergies.

EAACI Allergen Immunotherapy User's Guide

Allergen immunotherapy is a cornerstone in the treatment of allergic children. The clinical efficiency relies on a well-defined immunologic mechanism promoting regulatory T cells and downplaying the immune response induced by allergens. Clinical indications have been well documented for respiratory allergy in the presence of rhinitis and/or allergic asthma, to pollens and dust mites. Patients who have had an anaphylactic reaction to hymenoptera venom are also good candidates for allergen immunotherapy. Administration of allergen is currently mostly either by subcutaneous injections or by sublingual administration. Both methods have been extensively studied and have pros and cons. Specifically in children, the choice of the method of administration according to the patient's profile is important. Although allergen immunotherapy is widely used, there is a need for improvement. More particularly, biomarkers for prediction of the success of the treatments are needed. The strength and efficiency of the immune response may also be boosted by the use of better adjuvants. Finally, novel formulations might be more efficient and might improve the patient's adherence to the treatment. This user's guide reviews current knowledge and aims to provide clinical guidance to healthcare professionals taking care of children undergoing allergen immunotherapy.

Molecular diagnosis for allergen immunotherapy

The extensive use of allergen molecules in birth cohort studies revealed that atopic sensitization is a sequential IgE response to distinct non-cross-reacting molecules from the same allergenic source (ie, molecular spreading), starting with an initiator molecule. This phenomenon reaches different degrees of progression (monomolecular, oligomolecular, and polymolecular) according to the individual atopic propensity and allergen exposure, thus producing an extreme heterogeneity of IgE sensitization profiles in patient populations. In patients with allergic rhinitis, the broader the IgE molecular sensitization profile, the greater is the risk of asthma and other allergic comorbidities, such as oral allergy syndrome. Hence it has been proposed to anticipate immunologic intervention at disease onset (early allergen immunotherapy) or even earlier during the preclinical sensitization stage (allergen immunoprophylaxis). Diagnostic algorithms based on singleplex or multiplex molecular IgE tests allow the discrimination of genuine from cross-reacting sensitization and the selection of the right extracts for allergen immunotherapy composition. Patients with extreme molecular poly-sensitization and greater risk of asthma or other IgE-mediated comorbidities, can be easily identified by means of allergen microarray or macroarray procedures and might benefit from anti-IgE treatment. IgE molecular tests have opened the era of precision allergology, and their routine use should aim at cost-effectiveness, according to the principles of the Choosing Wisely initiative.

Real-life effect of a microcrystalline tyrosine adjuvanted mite immunotherapy in patients with allergic rhinitis

Aim: Evaluate the effectiveness and safety of immunotherapy with Acarovac Plus^® in a 1-year prospective multicentered real-life study. Methods: A total of 118 adults with allergic rhinitis sensitized to Dermatophagoides received subcutaneous immunotherapy with Acarovac Plus. Treatment outcomes were evaluated at baseline, 6 months and 1 year after treatment initiation. Primary end point was the evolution of the combined symptom and medication score. Secondary end points included other effectiveness outcomes and measurement of product tolerability. Results: Acarovac Plus induced significant improvements in primary and secondary end points after 6 months compared with baseline. These differences persisted after 1 year of treatment (p < 0.001; baseline vs 1 year): combined symptom and medication score (1.60 vs 0.79). No serious adverse events were recorded. Conclusion: Acarovac Plus for 1 year was effective and well tolerated in a real-life setting.

Bisphenol a Exposure, DNA Methylation, and Asthma in Children

Epidemiological studies have reported the relationship between bisphenol A (BPA) exposure and increased prevalence of asthma, but the mechanisms remain unclear. Here, we investigated whether BPA exposure and DNA methylation related to asthma in children. We collected urinary and blood samples from 228 children (Childhood Environment and Allergic Diseases Study cohort) aged 3 years. Thirty-three candidate genes potentially interacting with BPA exposure were selected from a toxicogenomics database. DNA methylation was measured in 22 blood samples with top-high and bottom-low exposures of BPA. Candidate genes with differential methylation levels were validated by qPCR and promoter associated CpG islands have been investigated. Correlations between the methylation percentage and BPA exposure and asthma were analyzed. According to our findings, MAPK1 showed differential methylation and was further investigated in 228 children. Adjusting for confounders, urinary BPA glucuronide (BPAG) level inversely correlated with MAPK1 promoter methylation (β = -0.539, p = 0.010). For the logistic regression analysis, MAPK1 methylation status was dichotomized into higher methylated and lower methylated groups with cut off continuous variable of median of promoter methylation percentage (50%) while performing the analysis. MAPK1 methylation was lower in children with asthma than in children without asthma (mean ± SD; 69.82 ± 5.88% vs. 79.82 ± 5.56%) (p = 0.001). Mediation analysis suggested that MAPK1 methylation acts as a mediation variable between BPA exposure and asthma. The mechanism of BPA exposure on childhood asthma might, therefore, be through the alteration of MAPK1 methylation. The mechanism of BPA exposure on childhood asthma might, therefore, be through the alteration of MAPK1 methylation.

Allergen-specific Immunotherapy for Inhalant Allergens in Children

Allergen-specific immunotherapy (AIT) for aeroallergens consists of the administration of standardized allergen extracts to patients with respiratory IgE-mediated diseases to the same allergen in order to achieve immune tolerance to the allergen and prevent the onset of symptoms. AIT is usually delivered by sublingual (SLIT), subcutaneous (SCIT) route. AIT with one or multiple allergens currently represents the only causal treatment able to change the natural history of allergic airway diseases. Significant progresses have been made in terms of AIT efficacy and safety. In this paper, mechanisms of action, indication and side effects of allergen immunotherapy are reviewed. SLIT and SCIT have been found to be effective in the treatment of asthma and rhinoconjunctivitis due to inhalant allergens. The route of AIT administration should be selected on availability, cost (dependent from the local health system), tolerability (better for SLIT), patient's preference (injections are less accepted in young children), and adherence (higher for SCIT beyond pediatric age). However, it should be taken into account that metanalyses on AIT do not consider that effectiveness and safety depend upon the product chosen for treatment. Each product should be separately assessed to avoid generalization on administration routes or age group that may affect the decision.

ICON: Diagnosis and management of allergic conjunctivitis

Ocular allergy (OA), interchangeably known as allergic conjunctivitis, is a common immunological hypersensitivity disorder affecting up to 40% of the population. Ocular allergy has been increasing in frequency, with symptoms of itching, redness, and swelling that significantly impacts an individual's quality of life (QOL). Ocular allergy is an often underdiagnosed and undertreated health problem, because only 10% of patients with OA symptoms seek medical attention, whereas most patients manage with over-the-counter medications and complementary nonpharmacological remedies. The clinical course, duration, severity, and co-morbidities are varied and depend, in part, on the specific ocular tissues that are affected and on immunologic mechanism(s) involved, both local and systemic. It is frequently associated with allergic rhinitis (commonly recognized as allergic rhino conjunctivitis), and with other allergic comorbidities. The predominance of self-management increases the risk of suboptimal therapy that leads to recurrent exacerbations and the potential for development of more chronic conditions that can lead to corneal complications and interference with the visual axis. Multiple, often co-existing causes are seen, and a broad differential diagnosis for OA, increasing the difficulty of arriving at the correct diagnosis(es). Ocular allergy commonly overlaps with other anterior ocular disease disorders, including infectious disorders and dry eye syndromes. Therefore, successful management includes overcoming the challenges of underdiagnosis and even misdiagnosis by a better understanding of the subtleties of an in-depth patient history, ophthalmologic examination techniques, and diagnostic procedures, which are of paramount importance in making an accurate diagnosis of OA. Appropriate cross-referral between specialists (allergists and eyecare specialists) would maximize patient care and outcomes. This would significantly improve OA management and overcome the unmet needs in global health.

Allergen immunotherapy (AIT) in asthma

Bronchial asthma remains one of the most common chronic diseases with a high degree of morbidity and still a considerable mortality with an increasing prevalence in many countries. Although remarkable progress has been made in the past decades in the medical treatment for asthma, curative or disease modifying approaches are still limited to allergen immunotherapy (AIT). Despite a plethora of potential immunological actions observed during AIT, the precise mechamisms that might exert beneficial effects especially in asthma remain unclear. Clinical studies in the past have suggested clinical benefits in symptom control and medication use with a small reduction in allergen-specific and non-specific bronchial hyperresponsiveness but these results were mainly derived from small, frequently suboptimally designed studies which were poorly comparable. Only recently have larger, dose ranging studies with well standardized allergens with patient relevant endpoints such as corticosteroid requirements for asthma control or the onset of exacerbations following inhaled corticosteroid (ICS) withdrawal corroborated the potential clinical effects of AIT in asthma, suggesting that it might replace some of the controller effects of ICS. In addition, newer, up-do-date designed studies support previous data that in patient populations at risk to develop asthma AIT might have a role in secondary prevention. Further studies on the long term effects as well as comparative studies are needed to further corroborate the role of AIT in the prevention and the control of asthma are needed.

Comparison of adverse events between cluster and conventional immunotherapy for allergic rhinitis patients with or without asthma: A systematic review and meta-analysis

BACKGROUND

Cluster schedule of allergen-specific immunotherapy (AIT) is a cost-effective choice for allergic rhinitis (AR) patients, but its safety has been questioned due to the greater dosages required at each treatment compared with conventional immunotherapy. It remains a question that whether cluster schedule leads to a higher risk of side effects.

OBJECTIVE

This study was designed to update the evidence and investigate whether cluster schedule leads to a higher risk of local adverse reactions (LARs) and systemic adverse reactions (SARs) than cluster schedule does.

METHODS

We searched the Cochrane Central Register of Controlled Trials, EMBASE and Medline thoroughly and included studies comparing cluster and conventional schedules. A meta-analysis of 5 outcomes related to adverse events was performed after bias and heterogeneity assessments. And as a result of language limitations, we considered only articles in Chinese and English.

RESULTS

5 observational studies and 6 interventional studies were included in the meta-analysis. There were no differences between cluster and conventional schedules when analyzing SARs by the number of patients, delayed SARs, grade 2 SARs and LARs. Analyses of SARs by injection, grade 1 SARs and LARs by injection in observational studies showed that cluster schedule had a lower risk of adverse events than did conventional schedule.

CONCLUSION

Our data suggest that cluster schedule is as safe as or even safer than conventional schedule for AR patients with or without asthma (AS).

Comparison of Six Different Allergen Extracts for Subcutaneous Specific Immunotherapy in Children: An Open-Labelled, Prospective, Controlled Observational Trial

BACKGROUND

Numerous products are available for subcutaneous (SCIT) and sublingual allergen-specific immunotherapy, but there are no information about the direct comparability regarding efficacy, safety, and tolerability of the different extracts.

AIMS

The aim of this open-labelled, prospective, controlled observational trial was to test the feasibility of a comparison of different products for SCIT in children.

METHODS

Pediatrician practices recruited patients with a confirmed diagnosis of a seasonal allergic rhinoconjunctivitis (AR) with or without asthma and an allergic sensitization against grass pollen allergen. Every patient was offered SCIT with one out of six allergen extracts: ALK SQ Depot, ALK Avanz, Allergovit, Depigoid, Purethal, Pollinex Quattro. Scores for symptoms and medications were calculated and the difference between treatment years and baseline were recorded.

RESULTS

In total, 284 were recruited and 255 children (89.8%; mean age 10.4, SD 3.54 years; 65% males) participated in this trial. Overall, 49,649 patient days were recorded in the electronic database (mean 183.2 days/patient). There was no significant difference in the AR and asthma symptom score or the medication score between the six different SCIT preparations. Similarly, no differences were observed in terms of safety and tolerability.

CONCLUSION

The comparison of different SCIT products using an online tool is feasible. Based on our preliminary data, all extracts indicated efficacy; however, larger groups would be necessary to demonstrate superiority or non-inferiority of one specific SCIT product.

The effect of regulatory T cells on tolerance to airborne allergens and allergen immunotherapy

Forkhead box P3-positive regulatory T (Treg) cells are essential mediators of tolerance against self-antigens and harmless exogenous antigens. Treg cell deficiencies result in multiple autoimmune and allergic syndromes in neonates. How Treg cells affect conventional allergies against aeroantigens, which are restricted to a few specific proteins released from inhaled particles, remains controversial. The hallmarks of antigen-specific loss of tolerance are allergen-specific T_H2 cells and IgE. However, difficulties in identifying the rare allergen-specific Treg cells have obscured the cellular basis of tolerance to aeroallergens, which is also a major obstacle for the rational design of novel and more efficient allergen-specific immunotherapies. Recent technological progress allowing characterization of allergen-specific effectors and Treg cells with minimal in vitro manipulation revealed their detailed contribution to tolerance. The data identified inhaled particles as immunodominant Treg cell targets in healthy and allergic subjects. Conversely, the supposed immunodominant major allergens being rapidly released from inhaled particles apparently do not actively induce tolerance but are ignored by the immune system. Here, the partially contradictory data on various allergen-specific T-cell types in healthy subjects, allergic patients, and patients undergoing allergen-specific immunotherapy are discussed and integrated into one model, postulating Treg cell-dependent and Treg cell-independent checkpoints of tolerance and allergy development.

Allergic eye disease in children and adolescents seeking eye care in India: Electronic medical records driven big data analytics report II

PURPOSE

To describe the demographics, clinical presentation and risk-factors of allergic eye disease (AED) in children and adolescents presenting to a multi-tier ophthalmology hospital network in India.

METHODS

This was a hospital-based cross-sectional study of 259,969 new patients (≤21 years of age) presenting between 2010 and 2018. Patients with a clinical diagnosis of AED were considered as cases. Data were collected using an electronic medical record system. Multiple logistic regression with odds ratios (OR) was performed to identify the high risk-factors of AED.

RESULTS

Overall, 26,309 (10.1%) children and adolescents were diagnosed with AED. The prevalence of AED was 0.3%, 6.6%, 18.3%, 15.8%, 8.1%, and 4.9% in infancy (<1 years), toddlerhood (1-2 years), early childhood (3-5 years), middle childhood (6-11 years), early adolescence (12-18 years) and late adolescence (18-21 years), respectively. Most patients with AED presented in spring and summer. Palpebral vernal keratoconjunctivitis was the commonest clinical form, seen in 42.8% of eyes. Corneal scarring, keratoconus, limbal stem cell deficiency and shield ulcers were seen in 2.4%, 1.4%, 0.4% and 0.3% of eyes, respectively. Male sex (OR 2.05); early and middle childhood age groups (OR 66.6; 59.1); higher socio-economic class (OR 1.46) and history of systemic allergy (OR 3.74) were identified as high-risk factors of AED.

CONCLUSION

About a tenth of the children and adolescents seeking eye care in India are affected by AED, which commonly affects boys with atopy, from middle to higher income families during their early to middle childhood and shows a self-limiting trend by late adolescence.

Options of immunotherapeutic treatments for children with asthma

Introduction: Asthma is the most common chronic disease in children. Avoiding triggers, and pharmacologic treatment with short acting beta-agonist, inhaler corticosteroids and anti-leukotriene are often enough to obtain symptoms control. Nevertheless, there is a subset of children with severe asthma and poor symptom control despite maximal therapy. In these patients, anti-IgE and anti-IL5 monoclonal antibodies are suggested as the fifth step of Global Initiative for Asthma guidelines. Area covered: Immunotherapeutic treatments are now suggested for asthma management. This article will discuss the available evidence on allergen immunotherapy and biologic drugs in pediatric asthma treatment. Expert opinion: Previously published studies demonstrated a good efficacy and safety profile of Allergen Immunotherapy in patients with mild-moderate asthma and sensitization to one main allergen. New understanding of mechanisms underlying severe asthma inflammation has allowed the identifications of specific biomarkers guiding the clinician in the choice of patient specific drug. Among the suggested immunotherapeutic options, omalizumab (blocking IgE) remains the first choice for atopic 'early onset' asthma in patients aged over 6 years. Instead, mepolizumab (blocking the IL5 ligand) should be considered for 'eosinophilic' asthma. Other biologic drugs are under consideration but data on the pediatric population are still lacking.

Sublingual immunotherapy alters salivary IgA and systemic immune mediators in timothy allergic children

BACKGROUND

Immunomodulatory effects of sublingual immunotherapy on systemic and mucosal mediators in allergic children are largely unexplored. The aim of this study was to investigate allergy-related cytokine and chemokine levels, as well as IgA-responses upon a 3-year treatment with timothy grass pollen sublingual immunotherapy in children with allergic rhinoconjunctivitis.

METHODS

From children included in the GRAZAX^® Asthma Prevention study, blood and saliva samples were analyzed at inclusion, after 3 years of treatment, and 2 years after treatment ending. By means of Luminex and ELISA methodologies, allergy-related cytokines and chemokines were measured in plasma samples and allergen-stimulated peripheral blood mononuclear cell supernatants. Furthermore, studies of total, secretory, and Phl p 1-specific salivary IgA antibodies were performed using the same methods.

RESULTS

GRAZAX^® -treated children exhibited significantly higher levels of Phl p 1-specific salivary IgA and serum IgG₄ , along with significantly lower skin prick test positivity, after 3 years of treatment and 2 years after treatment cessation. Additionally, plasma levels of the Th1-associated chemokines CXCL10 and CXCL11 were significantly higher in treated than untreated children at these time points. Timothy-induced ratios of IL-5/IL-13 over IFN-γ were significantly decreased after 3 years with active treatment, as were symptoms of allergic rhinitis in terms of both severity and visual analogue scale scores. However, no consistent correlations were found between the clinical outcomes and immunologic parameters.

CONCLUSION

Phleum pratense sublingual immunotherapy in grass pollen allergic children modulates the immune response in the oral mucosa as well as systemically-by increasing Th1-responses, decreasing Th2-responses, and inducing immunoregulatory responses-all signs of tolerance induction.

Novel therapeutic targets for allergic airway disease in children

The aim of precision medicine is setting up targeted therapies for selected patients that would ideally have high effectiveness and few side effects. This is made possible by targeted therapy drugs that selectively act on a specific pathway. Precision medicine is spreading to many medical specialties, and there is increasing interest in the context of allergic airway diseases, such as allergic rhinitis, chronic rhinosinusitis, and asthma. This review is an update of new targets in the treatment of childhood allergic upper airway diseases and asthma, including the most recent biologic drugs that have already been licensed or are in the pipeline to be tested with children.

Immunotherapy with grass pollen tablets reduces medication dispensing for allergic rhinitis and asthma: A retrospective database study in France

BACKGROUND

Moderate-to-severe allergic rhinitis (AR) may increase the risk of developing or worsening asthma, whereas treatment of AR with subcutaneously or sublingual allergen immunotherapy (SLIT) may slow this progression.

METHODS

In a retrospective real-world analysis, prescription fulfilment data were gathered from French retail pharmacies between 1 March 2012 and 31 December 2016. Using linear regression analyses, patients having received at least two prescriptions of grass pollen SLIT tablets over at least 2 successive years were compared with control patients having received symptomatic medications only.

RESULTS

A total of 1099 SLIT patients and 27 475 control patients were included in the main analysis. With regard to symptomatic AR medication dispensing, we observed a 50% decrease in the pre-index/follow-up ratio in the SLIT group, a 30% increase in the control group without age matching (P < 0.0001 vs SLIT) and a 20% increase in the control group with age matching (P < 0.0001 vs SLIT). During the follow-up, 11 (1.8%) and 782 (5.3%) patients initiated asthma treatment in the SLIT and control groups, respectively. The relative risk of medication dispensing for new asthma was lower in the SLIT group (by 62.5% [29.1%-80.1%] without age matching (P = 0.0025) and by 63.7% [31.5%-80.7%] with age matching; P = 0.0018). SLIT was also associated with slower progression of asthma medication dispensing during the follow-up period, relative to the control group (regression coefficient: -0.58 [-0.74 to 0.42] without age matching (P < 0.0001) and -0.61 [-0.76 to -0.46] with age matching; P < 0.0001).

CONCLUSION

Prescription of grass pollen SLIT tablets reduced the dispensing of AR and asthma medications in real life.

[Costs of allergic diseases and saving potential by allergen-specific immunotherapy : A personal assessment]

BACKGROUND

The burden of allergic diseases is of particular relevance for the economy and the social welfare and health insurance framework. Allergic rhinitis (AR) has a life-time prevalence of approximately 30% and is one of the most common chronic diseases with considerable socioeconomic impact thus leading to substantial direct, indirect and intangible costs. This article explores the common hypothesis that allergen-specific immunotherapy (ASIT) saves national economic expenses in the long term in comparison to other standard symptomatic treatment or no therapy.

METHODS

We conducted a selective search and analysis of the literature in PubMed and Medline including otherwise listed publications in German. Using a predefined model and data extrapolation over 9 years for data from different sources and short-term clinical studies we further discuss the problems and difficulties in analyzing heterogeneous datasets.

RESULTS

Using a health-economic model with currently available and accepted variables ASIT proves to be cost-effective in comparison to symptomatic treatment in allergic rhinitis; however, numerous parameters from other models have to be controlled, such as adherence to therapy and therapy discontinuation, heterogeneous costs for different treatment modalities, effect sizes with respect to symptoms including cross-influences with symptomatic rescue medication, duration of efficacy after treatment discontinuation and asthma protection.

DISCUSSION

The personal appraisal of the authors demonstrates not only the current knowledge but also the problems in health economical evaluation of ASIT in allergic diseases.