Immunotherapy with a standardized Dermatophagoides pteronyssinus extract. VI. Specific immunotherapy prevents the onset of new sensitizations in children

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.

A Review of Shared Decision-Making, Published Protocols, and Post-desensitization Strategies in Oral Immunotherapy (OIT)

PURPOSE OF REVIEW

The aim of this review is to highlight key published oral immunotherapy (OIT) protocols and post-desensitization strategies for the major food allergens and to cover important concepts to consider when evaluating OIT for food-allergic patients. Shared decision-making should help identify patient and family values which will help influence the type of evidence-based protocol and maintenance strategy to use.

RECENT FINDINGS

With food OIT emerging as a treatment option, there is a pressing need for patients, physicians, and other providers to have a nuanced understanding of the management choices available to them. There are now randomized controlled trials (RCT) of OIT for peanut, egg, milk, and wheat, and reports of cohorts of patients who have undergone OIT for tree nuts and sesame clinically. The current published protocols contain significant diversity in terms of starting dose, build-up schedule, maintenance dose, and even the product used for desensitization. Emerging data can help direct the long-term maintenance strategy for patients on OIT. Based on patient and family values elicited through the shared decision-making process, an OIT protocol may be selected that balances the level of desensitization, potential side effects, frequency of clinic visits, and potential to induce sustained unresponsiveness, among other factors. Once maintenance dosing is reached, most patients will need to maintain regular exposure to the food allergen to remain desensitized. The option to transition to commercial food products with equivalent amounts of food protein as the OIT maintenance dose would simplify the dosing process and perhaps improve palatability as well. Less frequent or decreased OIT dosing can provide practical benefits but may affect the level of desensitization and safety for some patients.

Construction by artificial intelligence and immunovalidation of hypoallergenic mite allergen Der f 36 vaccine

Background

The house dust mite (HDM) is widely recognized as the most prevalent allergen in allergic diseases. Allergen-specific immunotherapy (AIT) has been successfully implemented in clinical treatment for HDM. Hypoallergenic B-cell epitope-based vaccine designed by artificial intelligence (AI) represents a significant progression of recombinant hypoallergenic allergen derivatives.

Method

The three-dimensional protein structure of Der f 36 was constructed using Alphafold2. AI-based tools were employed to predict B-cell epitopes, which were subsequently verified through IgE-reaction testing. Hypoallergenic Der f 36 was then synthesized, expressed, and purified. The reduced allergenicity was assessed by enzyme-linked immunosorbent assay (ELISA), immunoblotting, and basophil activation test. T-cell response to hypoallergenic Der f 36 and Der f 36 was evaluated based on cytokine expression in the peripheral blood mononuclear cells (PBMCs) of patients. The immunogenicity was evaluated and compared through rabbit immunization with hypoallergenic Der f 36 and Der f 36, respectively. The inhibitory effect of the blocking IgG antibody on the specific IgE-binding activity and basophil activation of Der f 36 allergen was also examined.

Results

The final selected non-allergic B-cell epitopes were 25-48, 57-67, 107-112, 142-151, and 176-184. Hypoallergenic Der f 36 showed significant reduction in IgE-binding activity. The competitive inhibition of IgE-binding to Der f 36 was investigated using the hypoallergenic Der f 36, and only 20% inhibition could be achieved, which is greatly reduced when compared with inhibition by Der f 36 (98%). The hypoallergenic Der f 36 exhibited a low basophil-stimulating ratio similar to that of the negative control, and it could induce an increasing level of IFN-γ but not Th2 cytokines IL-5 and IL-13 in PBMCs. The vaccine-specific rabbit blocking IgG antibodies could inhibit the patients' IgE binding and basophil stimulation activity of Derf 36.

Conclusion

This study represents the first application of an AI strategy to facilitate the development of a B-cell epitope-based hypoallergenic Der f 36 vaccine, which may become a promising immunotherapy for HDM-allergic patients due to its reduced allergenicity and its high immunogenicity in inducing blocking of IgG.

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.

Decreased Basophil Activation against House Dust Mite after Japanese Cedar Pollen Subcutaneous Immunotherapy: A Retrospective Study

BACKGROUND

Allergen-specific immunotherapy (AIT), an established treatment for allergic diseases, prevents the development of other allergic manifestations. Although the mechanisms remain unclear, AIT has been shown to reduce basophil activation (BA) against nontarget allergens.

OBJECTIVES

The aim of this study was to assess immunological changes in Dermatophagoides farinae (Der f) after Japanese cedar pollen (JCP)-based subcutaneous immunotherapy (SCIT) monotherapy.

METHOD

The data of 16 patients (age: 6-37 years) with JCP-induced allergic rhinitis who were sensitive to Der f (serum Der f-specific immunoglobulin E [IgE] level >0.34 kUA/L) and received JCP-based SCIT for 5 years were reviewed retrospectively. BA by Der f and JCP extracts and serum-specific IgE and immunoglobulin G4 (IgG4) levels against these allergens were evaluated before and after completing 5 years of JCP-based SCIT monotherapy.

RESULTS

The areas under the dose-response curves of BA by Der f and JCP extracts were significantly reduced (p = 0.02 and p = 0.002, respectively). JCP-specific IgE levels decreased and JCP-specific IgG4 levels increased significantly (p < 0.001 for both), whereas Der f-specific IgE and IgG4 levels did not change significantly.

CONCLUSIONS

JCP-based SCIT monotherapy reduced Der f-specific BA. These findings suggest that JCP-based SCIT has the potential to modulate immune response toward nontarget allergens.

Potential Effects of AIT on Nonspecific Allergic Immune Responses or Symptoms

Allergen immunotherapy (AIT) is a treatment in which clinically corresponding allergens are administered to patients with allergic diseases, either by subcutaneous immunotherapy (SCIT) or sublingual immunotherapy (SLIT), or by oral immunotherapy (OIT) in the case of food allergy. Since etiological allergens are administered to patients, AIT is presumed to modify mainly allergen-specific immune responses. In bronchial asthma, AIT with house dust mites (HDM) alleviates clinical symptoms, suppresses airway hyperresponsiveness, and reduces medication doses of HDM-sensitive asthmatics. Moreover, AIT can suppress the symptoms of other allergic diseases associated with asthma including allergic rhinitis. However, AIT sometimes reduces allergic symptoms not induced by the responsible allergens, such as non-targeted allergens, in clinical settings. Furthermore, AIT can suppress the spread of sensitization to new allergens that are not targeted allergens by AIT, suggesting the suppression of allergic immune responses in an allergen-nonspecific manner. In this review, the nonspecific suppression of allergic immune responses by AIT is discussed. AIT has been reported to increase regulatory T cells that produce IL-10, transforming growth factor-β, and IL-35, IL-10-producing regulatory B cells, and IL-10-producing innate lymphoid cells. These cells can suppress type-2 mediated immune responses mainly through the production of anti-inflammatory cytokines or a cell-cell contact mechanism, which may be involved in the nonspecific suppression of allergic immune responses by AIT.

Chinese Guideline on Allergen Immunotherapy for Allergic Rhinitis: The 2022 Update

In the last few decades, there has been a progressive increase in the prevalence of allergic rhinitis (AR) in China, where it now affects approximately 250 million people. AR prevention and treatment include allergen avoidance, pharmacotherapy, allergen immunotherapy (AIT), and patient education, among which AIT is the only curative intervention. AIT targets the disease etiology and may potentially modify the immune system as well as induce allergen-specific immune tolerance in patients with AR. In 2017, a team of experts from the Chinese Society of Allergy (CSA) and the Chinese Allergic Rhinitis Collaborative Research Group (C2AR2G) produced the first English version of Chinese AIT guidelines for AR. Since then, there has been considerable progress in basic research of and clinical practice for AIT, especially regarding the role of follicular regulatory T (TFR) cells in the pathogenesis of AR and the use of allergen-specific immunoglobulin E (sIgE) in nasal secretions for the diagnosis of AR. Additionally, potential biomarkers, including TFR cells, sIgG4, and sIgE, have been used to monitor the incidence and progression of AR. Moreover, there has been a novel understanding of AIT during the coronavirus disease 2019 pandemic. Hence, there was an urgent need to update the AIT guideline for AR by a team of experts from CSA and C2AR2G. This document aims to serve as professional reference material on AIT for AR treatment in China, thus improving the development of AIT across the world.

Pharmacological Management of Allergic Rhinitis: A Consensus Statement from the Malaysian Society of Allergy and Immunology

The goal of allergic rhinitis (AR) management is to achieve satisfactory symptom control to ensure good quality of life. Most patients with AR are currently treated with pharmacotherapy. However, knowledge gaps on the use of pharmacotherapy still exist among physicians, particularly in the primary care setting, despite the availability of guideline recommendations. Furthermore, it is common for physicians in the secondary care setting to express uncertainty regarding the use of new combination therapies like intranasal corticosteroid plus antihistamine combinations. Inadequate treatment leads to significant reduction of quality of life that affects daily activities at home, work, and school. With these concerns in mind, a practical consensus statement was developed to complement existing guidelines on the rational use of pharmacotherapy in both the primary and secondary care settings.

Pediatric subcutaneous allergen immunotherapy

Subcutaneous immunotherapy (SCIT) is a widely used therapy for allergic rhinitis and asthma. It is a useful adjunct to standard medical management of these conditions that can lead to long-term benefits and possible resolution of symptoms. The benefits of SCIT, particularly for children, include avoiding prolonged use and side effects from medications, preventing new aeroallergen sensitizations, and reducing the risk of developing asthma. The primary risks of SCIT include local and systemic reactions. Standard schedules for SCIT include advancing through multiple doses usually in four vials (diluted to 1:1000) on a weekly basis; however, there are benefits of using accelerated schedules, especially for children who need to coordinate school and parent work schedules. Special considerations for pediatric patients include fear of needles, avoiding discomfort with injections, consent, optimal injection scheduling, and difficulty communicating about symptoms during reactions in very young children. Overall, SCIT can be a safe and beneficial therapy for children.

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.

The Effect of Allergen Immunotherapy on the Development of New Sensitization in Children

Aim

The protective effect of allergen immunotherapy against a new allergic sensitization is controversial. This study aimed to investigate the effect of allergen immunotherapy on new allergic sensitization in children.

Materials and Methods

The study included 50 patients who received immunotherapy for at least 3 years, and whose skin prick tests were repeated at intervals of at least 3 years (31 patients for house dust mite immunotherapy, 19 patients for pollen immunotherapy), and 69 controls with similar characteristics.

Results

The number of patients who developed a new sensitization was similar both in the groups of patients who received house dust mite and pollen immunotherapy, and the control group. There was no significant difference between the first and last skin prick tests of the patients who received house dust mite and pollen immunotherapy; however, in the control groups, a significant increase in sensitivity to tree pollens (n = 2, 5.4%; n = 8, 21.6%) and weed pollens (n = 7, 26.9%; n = 14, 53.8%) was detected (P = .031 and P = .039). While allergen sensitivities in the first tests of the pollen immunotherapy group and the control group were similar, weed pollen sensitivity was significantly higher in the last tests of the control group (n = 14, 53.8%; n = 4, 21.1%, P = .027). It was determined that the presence of weed pollen sensitization (OR: 8.1, 95% CI: 1.5-42.4) and having asthma (OR: 3.5, 95% CI: 1.3-10.8) increases the risk of new sensitization in all groups.

Conclusion

Allergen immunotherapy has been found to protect against new sensitization to tree and weed pollens. However, this effect was insignificant in the multivariate analysis. Weed pollen sensitization and the presence of asthma are related to the development of new sensitization.

Allergic Rhinitis in Children and Adolescents

Allergic rhinitis is a common disorder that regularly occurs in children and adolescents. The disease is associated with other allergic diseases, such as asthma, and it carries a heavy burden, with effects on sleep, school performance, and quality of life. Classic symptoms include sneezing, rhinorrhea, nasal obstruction, and nasal itching. When the eyes are involved, the term allergic rhinoconjunctivitis is used. Triggers may include airborne pollens, molds, dust mites, and animals. Skin or blood allergy testing can be a useful diagnostic modality that may guide therapy. Immunotherapy can prevent the development of further allergic sensitizations as well as subsequent asthma.

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

OBJECTIVE

Japanese cedar pollinosis is an endemic disease affecting a large proportion of Japan's population. Five seasons have passed since sublingual immunotherapy (SLIT) for Japanese cedar pollinosis was included in the public insurance coverage in Japan. In this study, we evaluated the clinical effects of long-term SLIT for Japanese cedar pollinosis on upper respiratory symptoms primarily represented by nasal symptoms and inflammation of the respiratory tract in the 2019 season, in which considerable amount of cedar pollen was dispersed.

METHODS

This study involved 95 patients who were undergoing SLIT for Japanese cedar pollinosis after the initiation at some point between 2014 and 2018, and this group of patients was compared with a control group comprising 21 patients receiving preseasonal prophylactic treatment (with a second-generation antihistaminic drug). We evaluated the patients' nasal/eye symptoms, total nasal symptom and medication score (TNSMS), and quality of life according to relevant guidelines. In addition, the levels of peripheral blood eosinophils, serum total IgE, Japanese cedar antigen-specific IgE, Cryj1-specific IgG4, and fractional exhaled nitric oxide (FENO) were measured as objective indices.

RESULTS

From the fourth season (SLIT4), nasal discharge, sneezing, nasal obstruction symptoms, and TNSMS significantly decreased compared with those in the preseasonal prophylactic treatment and SLIT1 groups. In the patients suspected to have eosinophilic airway inflammation (with a baseline FENO ≥25 ppb), the interannual variability of FENO levels significantly reduced after 5 years of treatment.

CONCLUSION

The efficacy of SLIT was noted from the first year of treatment, even in a year when pollen profusely dispersed. Thus, long-term continuous treatment with SLIT may alleviate nasal symptoms as well as eosinophilic airway inflammation.

The impact of moderate and severe asthma exacerbations on quality of life: a post hoc analysis of randomised controlled trial data

BACKGROUND

This paper reports the duration of moderate and severe exacerbations in patients with house dust mite induced allergic asthma and the impact on patients' quality of life.

METHODS

Post-hoc analyses were conducted using data collected during a phase III multi-national trial (MT-04) that investigated time to moderate or severe asthma exacerbation among 485 patients during withdrawal from inhaled corticosteroids. Patient diaries were analysed to ascertain duration of exacerbations. The impact on patients' quality of life was measured by calculating utilities for five health states using the EuroQol-5 Dimension (EQ-5D-3L) and Asthma Quality of Life Questionnaire (AQL-5D). A regression analysis predicted the disutility of moving from 'well controlled asthma' to the other four health states: 'partially controlled asthma', 'uncontrolled asthma', 'moderate exacerbation' and 'severe exacerbation'.

RESULTS

Two hundred four patients experienced exacerbations. Moderate and severe exacerbations involved statistically significant reductions in lung function compared to the constant peak expiratory flow observed for patients without exacerbations. Lung function decline occurred for 28 days, decreasing approximately 14 days before an exacerbation followed by a return to baseline over 14 days. Asthma symptoms, the use of short-acting β2-agonists, and frequency of nocturnal awakening all increased, starting 10-14 days before an exacerbation, and returned to baseline within 10-28 days following exacerbations. Compared to 'well controlled asthma', the disutility of having a 'moderate exacerbation' ranged from - 0.0834 to - 0.0921 (EQ-5D-3L) and from - 0.114 to - 0.121 (AQL-5D); and of having a 'severe exacerbation' from - 0.115 to - 0.163 (EQ-5D-3L) and from - 0.153 to - 0.217 (AQL-5D), depending on the length of the observation period.

CONCLUSIONS

The impact of moderate and severe exacerbations in house dust mite induced allergic asthma extends 14 days before and 28 days after the peak exacerbation event. The impact of exacerbations on patients' health-related quality of life (HRQoL) continues long after their occurrence.

Perspectives in Allergen-Specific Immunotherapy: Molecular Evolution of Peptide- and Protein-Based Strategies

Allergen-specific Immunotherapy (AIT), through repetitive subcutaneous or sublingual administrations of allergen extracts, represents up to now the unique treatment against allergic sensitizations. However, the clinical efficacy of AIT can be largely dependent on the quality of natural allergen extracts. Moreover, the long duration and adverse side effects associated with AIT negatively impact patient adherence. Tremendous progress in the field of molecular allergology has made possible the design of safer, shorter and more effective new immunotherapeutic approaches based on purified and characterized natural or recombinant allergen derivatives and peptides. This review will summarize the characteristics of these different innovative vaccines including their effects in preclinical studies and clinical trials.

Insights Into Mucosal Innate Immune Responses in House Dust Mite-Mediated Allergic Asthma

The prevalence of asthma has been rising steadily for several decades, and continues to be a major public health and global economic burden due to both direct and indirect costs. Asthma is defined as chronic heterogeneous inflammatory diseases characterized by airway obstruction, mucus production and bronchospasm. Different endotypes of asthma are being recognized based on the distinct pathophysiology, genetic predisposition, age, prognosis, and response to remedies. Mucosal innate response to environmental triggers such as pollen, cigarette smoke, fragrances, viral infection, and house dust mite (HDM) are now recognized to play an important role in allergic asthma. HDM are the most pervasive allergens that co-habitat with us, as they are ubiquitous in-house dusts, mattress and bedsheets, and feed on a diet of exfoliated human skin flakes. Dermatophagoides pteronyssinus, is one among several HDM identified up to date. During the last decade, extensive studies have been fundamental in elucidating the interactions between HDM allergens, the host immune systems and airways. Moreover, the paradigm in the field of HDM-mediated allergy has been shifted away from being solely a Th2-geared to a complex response orchestrated via extensive crosstalk between the epithelium, professional antigen presenting cells (APCs) and components of the adaptive immunity. In fact, HDM have several lessons to teach us about their allergenicity, the complex interactions that stimulate innate immunity in initiating and perpetuating the lung inflammation. Herein, we review main allergens of Dermatophagoides pteronyssinus and their interactions with immunological sentinels that promote allergic sensitization and activation of innate immunity, which is critical for the development of the Th2 biased adaptive immunity to HDM allergens and development of allergic asthma.

A survey of primary care practitioners' referral habits and recommendations of allergen-specific immunotherapy for canine and feline patients with atopic dermatitis

BACKGROUND

A recent pilot study of primary care veterinarians' attitudes regarding canine atopic dermatitis and initiation of allergen-specific immunotherapy (ASIT) revealed several barriers to specialist referral (in the USA) and use of ASIT as a treatment modality.

HYPOTHESIS/OBJECTIVES

The primary objective was to collect data on referral habits and ASIT practices among a much larger cohort of primary care veterinarians located around the world, and to explore barriers to referral and management of atopic diseases of dogs and cats with ASIT.

METHODS AND MATERIALS

An online survey, administered through the Veterinary Information Network (VIN, Davis, CA, USA), asked participants to self-report their referral habits and immunotherapy recommendations, and rate barriers and motivating factors using Likert-scale responses.

RESULTS

Of 827 survey responses, 97.6% identified as primary care practitioners. A larger number of practitioners (84.5%) reported seeing atopic dogs often, compared with atopic cats (9.7%). Fewer of these veterinarians (56.6%) referred atopic cats for specialist care, compared to atopic dogs (73.5%). Timely communication, sharing long-term management of the case, and provision of local continuing education were identified as factors associated with increased willingness to refer. A higher proportion of practitioners reported recommending ASIT for dogs (44.3%) than for cats (16.0%). Only 56.0% of respondents considered success rates of ASIT to be acceptable, while 27.9% were neutral on the topic.

CONCLUSIONS AND CLINICAL RELEVANCE

Dermatology specialists might build stronger relationships with referring veterinarians through timely case follow-up and provision of continuing education regarding the long-term benefits of ASIT and symptomatic management practices.

Allergen immunotherapy and biologics in respiratory allergy: friends or foes?

PURPOSE OF REVIEW

Allergen-specific immunotherapy has established as an indispensable disease-modifying treatment in allergy practice but its safety and efficacy might be furtherly improved by combining it with other drugs or therapeutic intervention that co-modulate immune type 2 immune networks.

RECENT FINDINGS

In the past two decades, clinical research focused on AIT and omalizumab co-treatment to improve both safety and long-term efficacy of allergic disease treatment. Recently, combination of AIT with other biologicals targeting different mediators of type 2 inflammation has been set up with interesting preliminary results. Moreover, AIT current contraindication might be overcome by contemporarily controlling underlying type 2 inflammation in severe atopic patients.

SUMMARY

AIT--biological combination treatment can realize a complex multitargeted treatment strategy allowing for consistently improving disease control and sparing steroid administration.

The evolution of allergy immunotherapy

OBJECTIVE

The objective of this review is to trace the evolution of the art and science of allergy immunotherapy (AIT).

DATA SOURCES

Original reports relating to the evolution of the concept of respiratory allergy and its specific treatment were identified by following references in journal articles, review articles, and allergy textbooks from the mid-20th century to the present.

STUDY SELECTIONS

Studies highlighting substantial milestones in the evolution of the practice of allergy immunotherapy were included.

RESULTS

The story of AIT begins with the recognition of hay fever as a distinct entity and subsequent studies that established grass pollen as one of the causes. This knowledge led several investigators, most notable Leonard Noon and John Freeman who worked at St. Mary's Hospital in London, to attempt to induce tolerance giving grass pollen extract by injection to their patients. After the publication of the work of Noon and Freeman in 1911, the practice of AIT spread rapidly and was applied to many other pollen allergens besides grass and for perennial rhinitis and asthma. The early studies were largely anecdotal, but over the past 60 to 70 years, studies of AIT have been conducted with increasingly sophisticated scientific methods. Nowadays, not only is the practice of AIT based on carefully conducted studies, but the underlying immunologic basis of allergy and the response to AIT have also been and still are being firmly established.

CONCLUSION

Both the art and the science behind the practice of AIT have been established by a solid base of clinical and immunologic studies.

The Cost-Effectiveness of Allergen Immunotherapy Compared with Pharmacotherapy for Treatment of Allergic Rhinitis and Asthma

This article evaluates the cost-effectiveness of allergy immunotherapy (AIT) in the treatment of allergic rhinitis, asthma, and other allergic conditions. An extensive search of the PubMed and Medline databases (up to December 2018) was conducted. There is strong evidence in the collective literature, which included individual studies and systematic reviews, that AIT is cost-effective in the management of allergic rhinitis and asthma as compared with standard drug treatment alone. The magnitude of AIT's cost-effectiveness is likely underestimated because most of the studies considered during-treatment costs and not the long-term benefits or preventive or prophylactic effects of AIT.

Planning and approach to allergen-specific immunotherapy in polyallergic patients

Allergy immunotherapy (AIT) is currently the only disease-modifying treatment for allergic-respiratory diseases. Polysensitization may increase the severity of current disease resulting in subsequent asthma development in patients with allergic rhinitis. Due to the absence of general recommendations for the practical approach to polysensitized patients, clinical management is not standardized. The correlation between sensitizations and clinical symptoms, elimination of possible pollen cross-reactivities and principles of homologous allergen groups will guide the allergists to deduce the most relevant allergens for AIT. In the highlight of the previously proposed approach strategies to polyallergic patients, hereby we propose a revised practical stepwise approach based on the current European Medicine Agency (EMA) guidelines. However, more supporting data from well-designed, controlled, future studies are needed to improve clinical management recommendations for AIT in polyallergic patients.

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.

Approach to Patients with Allergic Rhinitis: Testing and Treatment

This article evaluates the role of allergen immunotherapy (AIT) in the treatment of allergic rhinitis (AR). AIT has been shown to be effective in treating AR symptoms with resultant improvements in overall quality of life, comorbid illnesses, and medication requirements. Persistent clinical benefits have been shown years after AIT treatment discontinuation. AIT may prevent the progression of AR to asthma. AIT may more cost-effective than pharmacotherapy. Multiple individual studies and systematic reviews provide strong evidence for the clinical effectiveness of AIT in the treatment of AR. Cost-effectiveness and disease modification of AIT compared with standard drug treatment are additional advantages.

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.

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).

The effectiveness of sublingual immunotherapy for house dust mite-induced allergic rhinitis and its co-morbid conditions

Aim: We investigated sublingual immunotherapy for mite-induced allergic rhinitis and its comorbid allergic conditions. Patients & methods: A prospective case-controlled study of 120 patients (case = 80, control = 40) over 12 months. Results: There was 53.6% reduction in total rhinitis symptom score (p < 0.0001), but not in controls (-7.3%, p = 0.99). The total symptom scores for concurrent asthma decreased from 17.79 to 8.8 (p < 0.0001); for allergic conjunctivitis from 20.89 to 10.0 (p = 0.0002); for atopic dermatitis from 46.40 to 29.38 (p = 0.0004) and 74.6% of patients weaned off nasal topical steroids. The treatment-related adverse reactions were mild and self-limiting. Conclusion: Though sublingual immunotherapy may be more expensive than conventional treatments, it was an adjunctive therapy that improved not only the outcomes for allergic rhinitis, but also its comorbid allergic conditions.

Allergic Rhinitis in Children and Adolescents

Allergic rhinitis is a common disorder that regularly occurs in children and adolescents. The disease is associated with other allergic diseases, such as asthma, and it carries a heavy burden, with effects on sleep, school performance, and quality of life. Classic symptoms include sneezing, rhinorrhea, nasal obstruction, and nasal itching. When the eyes are involved, the term allergic rhinoconjunctivitis is used. Triggers may include airborne pollens, molds, dust mites, and animals. Skin or blood allergy testing can be a useful diagnostic modality that may guide therapy. Immunotherapy can prevent the development of further allergic sensitizations as well as subsequent asthma.

Does new sensitization correlate with nasal symptoms in children with allergic rhinitis?

OBJECTIVES

To evaluate the correlation between the increased number of sensitized allergens and nasal symptoms in patients with allergic rhinitis who were sensitized to house dust mites (HDMs).

METHODS

Among the patients who were enrolled in the Allergic Rhinitis Cohort Study for Kids, 174 children with rhinitis symptoms who were sensitized to HDMs were included in the analysis. Skin prick tests, serum total immunoglobulin E, eosinophil count, and bronchial provocation tests were carried out during the initial and 3-year follow-up visits. The patients were divided into two groups depending on the change in the number of sensitized allergens: increased number of sensitized allergens (group I) and maintained or reduced number of sensitized allergens (group II).

RESULTS

In the analysis of allergen sensitization from baseline to the 3-year follow-up, no significant correlation was observed between the changes in the number of allergens and the total nasal visual analog scale score (R²  < 0.001, P = .813). Furthermore, the comparison of demographic data and immunological factors between groups I and II did not show any significant differences. The changes in bronchial hyper-responsiveness were not significantly different between the two groups (P = 1.000).

CONCLUSION

New sensitization may not be correlated with nasal symptoms in patients in Asian countries where HDMs play a major role as a dominant allergen. Although further investigation must be conducted, the importance of new sensitization as an indicator of treatment outcome should be reconsidered in individuals in Asia.

LEVEL OF EVIDENCE

2b Laryngoscope, 130: 1864-1871, 2020.

[Analyses of Foxp3+ Treg cells and Tr1 cells in subcutaneous immunotherapy-treated allergic individuals in humans and mice]

Subcutaneous immunotherapy (SCIT) is a causative treatment for allergic diseases. More recently, it has become clear that regulatory T (Treg) cells are increased by SCIT. Treg cells are generally divided into two main groups: 1) CD25⁺ Foxp3⁺ CD4⁺ T cells (Foxp3⁺ Treg cells) and 2) IL-10-producing Foxp3^- CD4⁺ T cells (Tr1 cells). We demonstrated that the number of Tr1 cells in peripheral blood mononuclear cells in SCIT-treated pollinosis patients were significantly higher than that in non-SCIT-treated patients, but Foxp3⁺ Treg cells were not. Consistent with the results of human peripheral blood, Tr1 cells were increased in the lungs of asthmatic mice by SCIT, but Foxp3⁺ Treg cells were not. Moreover, in vitro-induced Tr1 cells were responded to the antigen to produce a large amount of IL-10 in in vitro and in vivo. Adoptive transfer of the induced Tr1 cells significantly suppressed the development of asthma. In any species of human and mouse, the increase in Tr1 cells rather than Foxp3⁺ Treg cells could be important for the effects of SCIT. The increased Tr1 cells by SCIT functionally suppressed allergic asthma probably via production of IL-10 in response to the specific antigen. Therefore, analyses of the induction mechanisms of Tr1 cells and search for compounds which induce Tr1 cells are thought to lead to development of more efficient SCIT.

BSACI guideline for the diagnosis and management of allergic and non-allergic rhinitis (Revised Edition 2017; First edition 2007)

This is an updated guideline for the diagnosis and management of allergic and non-allergic rhinitis, first published in 2007. It was produced by the Standards of Care Committee of the British Society of Allergy and Clinical Immunology, using accredited methods. Allergic rhinitis is common and affects 10-15% of children and 26% of adults in the UK, it affects quality of life, school and work attendance, and is a risk factor for development of asthma. Allergic rhinitis is diagnosed by history and examination, supported by specific allergy tests. Topical nasal corticosteroids are the treatment of choice for moderate to severe disease. Combination therapy with intranasal corticosteroid plus intranasal antihistamine is more effective than either alone and provides second line treatment for those with rhinitis poorly controlled on monotherapy. Immunotherapy is highly effective when the specific allergen is the responsible driver for the symptoms. Treatment of rhinitis is associated with benefits for asthma. Non-allergic rhinitis also is a risk factor for the development of asthma and may be eosinophilic and steroid-responsive or neurogenic and non- inflammatory. Non-allergic rhinitis may be a presenting complaint for systemic disorders such as granulomatous or eosinophilic polyangiitis, and sarcoidoisis. Infective rhinitis can be caused by viruses, and less commonly by bacteria, fungi and protozoa.

Mind the gaps: Clinical trial concepts to address unanswered questions in aeroallergen immunotherapy-An NIAID/AHRQ Workshop

The Agency for Healthcare Research and Quality and the National Institute of Allergy and Infectious Diseases organized a workshop to develop trial concepts that could improve the use and effectiveness of aeroallergen immunotherapy (AAIT). Expert groups were formed to accomplish the following tasks: (1) propose a study design to compare the effectiveness and safety of subcutaneous versus sublingual AAIT; (2) propose a study design to compare the effectiveness and safety of AAIT by using 1 or a few allergens versus all or most allergens to which a patient is sensitized; (3) propose a study design to determine whether AAIT can alter the progression of childhood allergic airways disease; and (4) propose a study design to determine the optimal dose and duration of AAIT to achieve maximal effectiveness with acceptable safety. Study designs were presented by the workgroups, extensively discussed at the workshop, and revised for this report. The proposed trials would be of long duration and require large highly characterized patient populations. Scientific caveats and feasibility matters are discussed. These concepts are intended to help the development of clinical trials that can address some of the major questions related to the practice of AAIT for the management and prevention of allergic airways disease.

Early Intervention is Important to Prevent Sensitization to New Allergens

We review current management for allergic rhinitis and possible new treatments for this condition. Management of allergic rhinitis includes promotion of protective factors, avoidance of allergens, and possibly immunotherapy. In recent years, the incidence of allergic rhinitis has increased in many countries. Early intervention at different stages is an important part of management. Allergic disease in infants has been described as the allergic march, commencing with atopic dermatitis accompanied by infantile asthma and progressing to perennial allergic rhinitis induced by house dust mite allergy. In order to prevent polysensitization, allergen-specific immunotherapy should probably be initiated at an earlier age, especially in children with rhinitis who show monosensitization to house dust mite antigens.

Component-Resolved Diagnosis in Allergic Rhinitis and Asthma

BACKGROUND

Allergic rhinitis and asthma are highly prevalent chronic inflammatory diseases leading to restrictions in the patient's quality of life and high costs for healthcare systems. Both diseases are associated with the presence of specific IgE (sIgE) against aeroallergens. This review aims to examine the importance of molecular allergy diagnostics in the assessment and management of these disorders.

CONTENT

The "U-shaped" approach, proposed by the European Academy of Allergy and Clinical Immunology, combines conventional allergy diagnostics with the benefits of component-resolved diagnosis (CRD) and offers important additional information regarding the patient's sensitization pattern, especially in complex clinical cases such as polysensitization or idiopathic reactions, thus avoiding overuse of in vitro and in vivo IgE diagnostics. CRD may help the clinician to identify the cause of an allergy and, in the case of complex polysensitization, uncover possible cross-reactivity. Polysensitization, especially to inhalant allergens, is associated with the clinical appearance of asthma and allergic rhinitis; important risk factors for the latter are the major allergens Fel d 1 and Can f 1. Importantly, information on molecular sensitization patterns significantly influences the choice of specific immunotherapy and reduces its overprescription.

CONCLUSION

At present, allergy diagnostics largely rely on clinical history, physical examination, and in vivo IgE testing. However, in vitro diagnostics including CRD are currently finding their way into the clinical routine and can offer additional information on the patient's sensitization profile and treatment responsiveness.

Is Allergen Immunotherapy in Children Disease Modifying? A Review of the Evidence

PURPOSE OF REVIEW

Although evidence supports a beneficial effect of allergen immunotherapy on the symptoms of allergic respiratory disease and food allergy, it is not clear whether immunotherapy modifies the natural history of these conditions.

RECENT FINDINGS

In aeroallergen immunotherapy, studies suggest that prevention of asthma can be attained. Less evident is the ability of immunotherapy to prevent new allergen sensitizations and more studies are needed to test whether immunotherapy can continue suppressing airway symptoms after treatment discontinuation. In food allergen immunotherapy, there is evidence that unresponsiveness to a food challenge can be sustained in some treatment recipients, but little knowledge exists as to the dose and duration of treatment that can optimize this effect. Suggestive evidence exists that allergen immunotherapy can modify allergic disease in children, but definitive studies are lacking. More research in the field is required.

Long-term safety of subcutaneous immunotherapy with TO-204 in Japanese patients with house dust mite-induced allergic rhinitis and allergic bronchial asthma: Multicenter, open label clinical trial

BACKGROUND

To evaluate the long-term safety of subcutaneous immunotherapy with TO-204, a standardized house dust mite (HDM) allergen extracts, we conducted a multicenter, open label clinical trial.

METHODS

Japanese patients aged 5-65 years were eligible for the study, if they had HDM-induced allergic rhinitis (AR), allergic bronchial asthma (BA), or both. TO-204 was administered in a dose titration scheme, and the maintenance dose was determined according to the predefined criteria. The treatment period was 52 weeks, and patients who were willing to continue the treatment received TO-204 beyond 52 weeks. This clinical trial is registered at the Japan Pharmaceutical Information Center (Japic CTI-121900).

RESULTS

Between July 2012 and May 2015, 44 patients (28 with AR and 16 with allergic BA) were enrolled into the study. All patients were included in the analysis. The duration of treatment ranged from 23 to 142 weeks and the median maintenance dose was 200 Japanese allergy units (JAU). Adverse events occurred in 22 patients (50%). The most common adverse event was local reactions related to the injection sites. Four patients experienced anaphylactic reactions when they were treated with the dose of 500 JAU. Two patients experienced anaphylactic shock with the doses of 1000 JAU at onset. These 6 patients could continue the study with dose reduction.

CONCLUSIONS

Safety profile of TO-204 was acceptable in Japanese patients with HDM-induced AR or allergic BA. Higher doses should be administered carefully, because the risk of anaphylaxis increased at doses of 500 or 1000 JAU.

Steroid sparing effect of sublingual immunotherapy: real life study in mono/polisensitized children with asthma

AIM

Steroid-sparing effect of sublingual immunotherapy (SLIT) in mono/polisensitized asthmatic children were evaluated.

MATERIALS AND METHODS

Children undergoing allergen-specific SLIT between 2010 and 2014 were included. Asthma control and usage/dose of inhaled corticosteroid (ICS) in the previous year was determined. Asthma control without ICS need ≥6 months was defined as 'ICS avoidance'.

RESULTS

90 children (mean ± SD age 8.92 ± 4.17 years) were enrolled, 56.7% (n = 60) being polysensitized. Mono, 2-simultaneous and multiple-pollen-mix allergen SLIT were prescribed in 84.4, 17.8 and 7.8%, respectively. ICS was avoided in 70%, with no significant difference in mono- versus poly-sensitized patients. ICS-avoidance rates in mono-allergen, pollen-mixture and 2-simultaneous-allergen SLIT were 93.6, 83.3 and 73.7%, respectively. Longer-duration SLIT resulted in significantly more ICS-avoidance (p:0.0001).

CONCLUSION

SLIT with mono/multiple-mixed/simultaneous allergens in childhood asthma resulted in retained-avoidance of ICS. Steroid-sparing effect of SLIT in polysensitized children warrants further investigation.

Induction of bystander tolerance and immune deviation after Fel d 1 peptide immunotherapy

BACKGROUND

Treatment of patients with cat allergy with peptides derived from Fel d 1 (the major cat allergen) ameliorated symptoms of cat allergy in phase 2 clinical trials.

OBJECTIVE

We sought to demonstrate that the tolerance induced by Fel d 1 peptide immunotherapy can be exploited to reduce allergic responses to a second allergen, ovalbumin (OVA), in mice sensitized dually to OVA and Fel d 1.

METHODS

Induction of tolerance to OVA was achieved through simultaneous exposure to both allergens after peptide treatment. Functional tolerance to each allergen was assessed in a model of allergic airways disease in which treated mice were protected from eosinophilia, goblet cell hyperplasia, and T_H2 cell infiltration.

RESULTS

Suppression of allergic responses to cat allergen challenge was associated with significant increases in numbers of CD4⁺CD25⁺Foxp3⁺ T cells, IL-10⁺ cells, and CD19⁺IL-10⁺ B cells, whereas the response to OVA was associated with a marked reduction in numbers of T_H2 cytokine-secreting T cells and less prominent changes in outcomes associated with immune regulation.

CONCLUSIONS

These observations suggest that immune tolerance induced by peptide immunotherapy can be used experimentally to treat an allergic response to another allergen and that the molecular mechanisms underlying induction of tolerance to a treatment-specific allergen and a bystander allergen might be different.

Immunotherapy of house dust mite allergy

House dust mite (HDM) is a predominant source of indoor aeroallergen worldwide, which induces allergic diseases including allergic rhinoconjunctivitis, allergic asthma, atopic eczema and other allergic skin diseases. Allergen specific immunotherapy (AIT) is the only potential disease-modifying treatment of HDM allergic subjects. However, AIT remains underused due to no universally accepted allergen standardization and a shortage of rigorous clinical studies to confirm safety and efficacy. With the effort of doctors and researchers in allergy field, efficacy, safety, standardization and strategy of AIT are being continuously developed. This review presents the updated research based on recently published trials and meta-analyses.

Preventing new sensitization and asthma onset by allergen immunotherapy: the current evidence

PURPOSE OF REVIEW

Specific allergen immunotherapy is considered a key candidate for a successful preventive intervention in atopic diseases. The strong association of atopic manifestations such as rhinitis and asthma with atopic sensitizations (specific serum IgE) provide a rationale for early intervention in childhood and adolescence.

RECENT FINDINGS

Currently, the documentation of the disease-modifying intervention effects is limited to the secondary prevention of asthma symptoms in children with allergic rhinoconjunctivitis. These effects appear to be rather allergen specific than nonspecific.

SUMMARY

Documentation on disease modification including a reduction of asthma symptoms in children, particularly with grass pollen tablets has become quite robust. It is not clear up to now, if the new onset of allergic sensitizations can be modified. So far data on primary prevention are not conclusive.

Treatment of Allergic Rhinitis as a Strategy for Preventing Asthma

PURPOSE OF REVIEW

To evaluate the impact of allergic rhinitis (AR) on the development of asthma and to update readers on recent literature suggesting that early treatment of allergic subjects with immunotherapy may prevent asthma onset.

RECENT FINDINGS

AR is frequently associated with asthma, leading to the concept that these two conditions are different aspects of the same disease. There is increasing evidence that AR precedes the onset of asthmatic symptoms and current treatment strategies are beneficial in symptom control with no impact prevention. There is limited knowledge about the risk factors responsible for the progression of AR to asthma, though recent data supports the notion that it is possible to prevent asthma onset by allergen immunotherapy. Despite significant advances in specific immunotherapy (SIT) therapy strengthening its efficacy in AR and possible prevention of progression to asthma, the adoption of this therapeutic strategy is still restricted in comparison to therapies directed towards treatment of AR symptoms. Unlike corticosteroids and other symptomatic therapies, the benefit of SIT treatment in allergic individuals has been shown to prevent the development of allergic conditions. Hence, large well-conducted randomized clinical trials with long-term efficacy of SIT are required to confirm or refute the concept that SIT may abrogate the progression of AR to asthma in patients.

A critical appraisal on AIT in childhood asthma

ABSTRACT

Allergen immunotherapy (AIT) is the only disease-modifying treatment approved for allergic rhinitis and allergic asthma and represents a suitable therapeutic option, especially in childhood, to modify the progression of respiratory allergic diseases. Starting from the previous "generic class effect" evaluation, as testified by the numerous meta analyses, AIT is now considered a product-specific pathogenic-oriented treatment.

BACKGROUND

AIT was empirically proposed more than one century ago in the subcutaneous form (SCIT), but the IgE-mediated mechanism of allergy was elucidated only after 50 years of clinical use of the treatment. The sublingual administration (SLIT) was developed during the 1980 ties, to achieve an improvement in safety and convenience. While SCIT is approved in the United States for the treatment of asthmatic patients with more than 12 years, so far few trials evaluated the clinical efficacy and safety of SLIT in children with allergic asthma, although the indications and some aspects remain unclear. Certainly, due to compliance problems, the age below 3 years may be reasonably considered a practical contraindication.

CONCLUSIONS

Given that some specific AIT products are effective and approved as drugs (AIFA, EMA, FDA), the use in children is still debated. Some aspects still need robust confirm: (a) the safety of AIT in asthma; (b) the optimal regimen of administration; (c) the role of AIT as preventative treatment for asthma development.