Real-world benefits of allergen immunotherapy for birch pollen-associated allergic rhinitis and asthma

Advances and recent developments in asthma in 2020

In this review, we discuss recent publications on asthma and review the studies that have reported on the different aspects of the prevalence, risk factors and prevention, mechanisms, diagnosis, and treatment of asthma. Many risk and protective factors and molecular mechanisms are involved in the development of asthma. Emerging concepts and challenges in implementing the exposome paradigm and its application in allergic diseases and asthma are reviewed, including genetic and epigenetic factors, microbial dysbiosis, and environmental exposure, particularly to indoor and outdoor substances. The most relevant experimental studies further advancing the understanding of molecular and immune mechanisms with potential new targets for the development of therapeutics are discussed. A reliable diagnosis of asthma, disease endotyping, and monitoring its severity are of great importance in the management of asthma. Correct evaluation and management of asthma comorbidity/multimorbidity, including interaction with asthma phenotypes and its value for the precision medicine approach and validation of predictive biomarkers, are further detailed. Novel approaches and strategies in asthma treatment linked to mechanisms and endotypes of asthma, particularly biologicals, are critically appraised. Finally, due to the recent pandemics and its impact on patient management, we discuss the challenges, relationships, and molecular mechanisms between asthma, allergies, SARS-CoV-2, and COVID-19.

Biomarkers for diagnosis and prediction of therapy responses in allergic diseases and asthma

Modern health care requires a proactive and individualized response to diseases, combining precision diagnosis and personalized treatment. Accordingly, the approach to patients with allergic diseases encompasses novel developments in the area of personalized medicine, disease phenotyping and endotyping, and the development and application of reliable biomarkers. A detailed clinical history and physical examination followed by the detection of IgE immunoreactivity against specific allergens still represents the state of the art. However, nowadays, further emphasis focuses on the optimization of diagnostic and therapeutic standards and a large number of studies have been investigating the biomarkers of allergic diseases, including asthma, atopic dermatitis, allergic rhinitis, food allergy, urticaria and anaphylaxis. Various biomarkers have been developed by omics technologies, some of which lead to a better classification of distinct phenotypes or endotypes. The introduction of biologicals to clinical practice increases the need for biomarkers for patient selection, prediction of outcomes and monitoring, to allow for an adequate choice of the duration of these costly and long‐lasting therapies. Escalating healthcare costs together with questions about the efficacy of the current management of allergic diseases require further development of a biomarker‐driven approach. Here, we review biomarkers in diagnosis and treatment of asthma, atopic dermatitis, allergic rhinitis, viral infections, chronic rhinosinusitis, food allergy, drug hypersensitivity and allergen immunotherapy with a special emphasis on specific IgE, the microbiome and the epithelial barrier. In addition, EAACI guidelines on biologicals are discussed within the perspective of biomarkers.

Advances and novel developments in allergic rhinitis

Allergic rhinitis (AR) is an upper airway disease with high prevalence in the world, and therefore needs to be thoroughly investigated and treated accordingly. Although the mechanisms underlying the pathology and treatment of AR have been widely studied, many aspects of AR are still unclear and warrant further investigations. The purpose of the present review was therefore to report recently published papers, which highlight the novel mechanisms and treatments of AR. These include role of environment, important proteins and cells, and some other factors in the pathogenesis of AR; as well as the role of immunotherapy and biologics in the treatment of AR.

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.

Mechanisms of allergen-specific immunotherapy and allergen tolerance

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

Tolerance mechanisms in allergen immunotherapy

PURPOSE OF REVIEW

Allergen immunotherapy is the only treatment modality which alters the natural course of allergic diseases by restoring immune tolerance against allergens. Deeper understanding of tolerance mechanisms will lead to the development of new vaccines, which target immune responses and promote tolerance.

RECENT FINDINGS

Successful allergen immunotherapy (AIT) induces allergen-specific peripheral tolerance, characterized mainly by the generation of allergen-specific Treg cells and reduction of Th2 cells. At the early phase, AIT leads to a decrease in the activity and degranulation of mast cells and basophils and a decrease in inflammatory responses of eosinophils in inflamed tissues. Treg cells show their effects by secreting inhibitory cytokines including interleukin (IL)-10, transforming growth factor-β, interfering with cellular metabolisms, suppressing antigen presenting cells and innate lymphoid cells (ILCs) and by cytolysis. AIT induces the development of regulatory B cells producing IL-10 and B cells expressing allergen-specific IgG4. Recent investigations have demonstrated that AIT is also associated with the formation of ILC2reg and DCreg cells which contribute to tolerance induction.

SUMMARY

Research done so far, has shown that multiple molecular and cellular factors are dysregulated in allergic diseases and modified by AIT. Studies should now focus on finding the best target and ideal biomarkers to identify ideal candidates for AIT.

Can we identify allergic rhinitis from administrative data: A validation study

BACKGROUND

Important insights on, for example, prevalence, disease progression, and treatment of allergic rhinitis can be obtained from large-scale database studies if researchers are able to identify allergic individuals. We aimed to assess the validity of 13 different algorithms based on Danish nationwide prescription and/or hospital data to identify adults with allergic rhinitis.

METHODS

Our primary gold standard of allergic rhinitis was a positive serum specific IgE (≥0.35) and self-reported nasal symptoms retrieved from two general health examination studies conducted in Danish adults (18-69 years) during 2006 to 2008 (n = 3416) and 2012 to 2015 (n = 7237). The secondary gold standard of allergic rhinitis was self-reported physician diagnosis. We calculated sensitivity, specificity, positive predictive value (PPV), negative predictive value, and corresponding 95% confidence intervals (95% CI) for each register-based algorithm in the two time periods.

RESULTS

Sensitivity (≤0.40) was low for all algorithms irrespective of definition of allergic rhinitis (gold standard) or time period. The highest PPVs were obtained for algorithms requiring both antihistamines and intranasal corticosteroids; yielding a PPV of 0.69 (0.62-0.75) and a corresponding sensitivity of 0.10 (0.09-0.12) for the primary gold standard of allergic rhinitis in 2012 to 2015.

CONCLUSION

Algorithms based on both antihistamines and intranasal corticosteroids yielded the highest PPVs. However, the PPVs were still moderate and came at the expense of low sensitivity when applying the strict primary gold standard (sIgE and nasal symptom).

Filling the Antibody Pipeline in Allergy: PIPE Cloning of IgE, IgG1 and IgG4 against the Major Birch Pollen Allergen Bet v 1

Birch pollen allergy is among the most prevalent pollen allergies in Northern and Central Europe. This IgE-mediated disease can be treated with allergen immunotherapy (AIT), which typically gives rise to IgG antibodies inducing tolerance. Although the main mechanisms of allergen immunotherapy (AIT) are known, questions regarding possible Fc-mediated effects of IgG antibodies remain unanswered. This can mainly be attributed to the unavailability of appropriate tools, i.e., well-characterised recombinant antibodies (rAbs). We hereby aimed at providing human rAbs of several classes for mechanistic studies and as possible candidates for passive immunotherapy. We engineered IgE, IgG1, and IgG4 sharing the same variable region against the major birch pollen allergen Bet v 1 using Polymerase Incomplete Primer Extension (PIPE) cloning. We tested IgE functionality and IgG blocking capabilities using appropriate model cell lines. In vitro studies showed IgE engagement with FcεRI and CD23 and Bet v 1-dependent degranulation. Overall, we hereby present fully functional, human IgE, IgG1, and IgG4 sharing the same variable region against Bet v 1 and showcase possible applications in first mechanistic studies. Furthermore, our IgG antibodies might be useful candidates for passive immunotherapy of birch pollen allergy.

Advances in allergen immunotherapy for asthma

PURPOSE OF REVIEW

Allergen immunotherapy (AIT) is a well-known disease-modifying intervention for allergic diseases. Its benefit in allergic asthma, ranging from prevention to facilitating asthma control, is yet to be clarified.

RECENT FINDINGS

In 2017, following several well-designed randomised controlled trials (RCTs) with house-dust mites (HDM) sublingual (SLIT) tablets in asthma, global initiative for asthma (GINA) guidelines highlighted the need to treat the allergic component of asthma. In 2019, the European Academy of Allergy and Clinical Immunology published the first comprehensive guidelines for HDM AIT in allergic asthma, formulating separate recommendations for subcutaneous, SLIT drops, and SLIT tablets. Significant steps were undertaken in understanding the mechanisms of allergic asthma, facilitating the stratified approach for selecting responders and in translating the immune-modulation effect in achieving long-term control of the chronic inflammation in asthma.

SUMMARY

Currently existing guidelines recommend AIT as a therapeutic option in controlled or partially controlled HDM allergic asthma. Limited data are available for pollen, molds and pets, as well as for the severe allergic asthma population. The challenge for the future research will be to clarify the subendotypes of allergic asthma responding to AIT, the mechanisms facilitating its' preventive and disease-modifying effect, the optimal duration of the treatment, and route of administration.

Real-world evidence of subcutaneous allergoid immunotherapy in house dust mite-induced allergic rhinitis and asthma

BACKGROUND

The objective of this study was to analyze the effectiveness of allergen immunotherapy (AIT) with an allergoid in the treatment of house dust mites (HDM)-induced allergic rhinitis and/or asthma based on recent real-life data. The outcomes were measured using asthma incidence and consumption of corresponding medications as the indicator of persisting symptoms.

METHODS

In this retrospective cohort analysis of a German longitudinal prescription database, patients who received at least two relevant mite AIT prescriptions in two different successive seasonal cycles were compared with non-AIT patients who received at least three symptomatic allergic rhinitis (AR) prescriptions in successive mite seasons. Study endpoints included AR progression, asthma progression, asthma occurrence, and therapy adherence. We used multivariate regression analyses to estimate the effects of AIT, adjusting for relevant variables.

RESULTS

This study included 2350 patients receiving a mite allergoid and 64 740 control patients. After up to 6 years of follow-up, patients treated with mite allergoid required significantly fewer AR and asthma prescriptions (59.7% vs 10.8%) than the control group, and the probability of asthma development was significantly lower. The adherence of patients receiving allergoid was 63.8% at the end of the second year and 38.6% at the end of the third year.

CONCLUSIONS

This real-world evidence confirms the good efficacy of subcutaneous AIT with HDM mite allergoid in the treatment of allergic rhinitis and/or asthma. Up to 6 years of follow-up revealed significant effects in allergic rhinitis by measuring the number of AR medications and demonstrating significant reductions in asthma medications.

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.

Towards definitive management of allergic rhinitis: best use of new and established therapies

BACKGROUND

Allergic rhinitis (AR) is an inflammatory disease of the nasal mucosa impacting up to 25% of Canadians. The standard of care for AR includes a treatment plan that takes into account patient preferences, the severity of the disease, and most essentially involves a shared decision-making process between patient and provider.

BODY

Since their introduction in the 1940s, antihistamines (AHs) have been the most utilized class of medications for the treatment of AR. First-generation AHs are associated with adverse central nervous system (CNS) and anticholinergic side effects. On the market in the 1980s, newer generation AHs have improved safety and efficacy. Compared to antihistamines, intranasal corticosteroids (INCS) have significantly greater efficacy but longer onset of action. Intranasal AH and INCS combinations offer a single medication option that offers broader disease coverage and faster symptom control. However, cost and twice-per-day dosing remain a major limitation. Allergen immunotherapy (AIT) is the only disease-modifying option and can be provided through subcutaneous (SCIT) or sublingual (SLIT) routes. While SCIT has been the definitive management option for many years, SLIT tablets (SLIT-T) have also been proven to be safe and efficacious.

CONCLUSION

There is a range of available treatment options for AR that reflect the varying disease length and severity. For mild to moderate AR, newer generation AHs should be the first-line treatment, while INCS are mainstay treatments for moderate to severe AR. In patients who do not respond to INCS, a combination of intranasal AH/INCS (AZE/FP) should be considered, assuming that cost is not a limiting factor. While SCIT remains the option with the most available allergens that can be targeted, it has the potential for severe systemic adverse effects and requires weekly visits for administration during the first 4 to 6 months. SLIT-T is a newer approach that provides the ease of being self-administered and presents a reduced risk for systemic reactions. In any case, standard care for AR includes a treatment plan that takes into account disease severity and patient preferences.

Clinical Practice of Allergen Immunotherapy for Allergic Rhinoconjunctivitis and Asthma: An Expert Panel Report

Allergen immunotherapy (AIT) reduces symptoms and medication use associated with allergic rhinitis with or without conjunctivitis and allergic asthma. Although several AIT guidelines exist, there remain unanswered questions about AIT that are relevant to everyday practice. Our objective was to prepare an evidence-based overview addressing the practical aspects of AIT in clinical practice based on published evidence and the experience of international experts in the field. Topics covered include interpretation and translation of clinical trial data into everyday clinical practice (eg, allergen doses and treatment duration), assessment of risk and treatment of local and systemic allergic reactions, recommendations for improvement of AIT guidelines, and identification of appropriate data for seeking regulatory approval, to name a few. Many informational gaps in AIT practice need further evaluation as products and practices evolve.

Dc-specific aptamer decorated gold nanoparticles: A new attractive insight into the nanocarriers for allergy epicutaneous immunotherapy

Recently, the main goal of many allergy epicutaneous immunotherapy (EPIT) studies is to enhance the allergen delivery through the intact skin. Therefore, applying new strategies for tackling this issue are inevitable. For this purpose, ten groups of Che a 2-sensitized BALB/c mice were epicutaneously treated for a 6-week period with the rChe a 2-GNPs-Aptamer, rChe a 2-GNPs-Aptamer + skin-penetrating peptides (SPPs), rChe a 2-GNPs, rChe a 2, GNPs, and PBS. Afterward, the serum IgE and IFN-γ, TGF-β, IL-10, IL-4, IL-17a cytokine production, NALF analysis, and lung/nasal histological examinations were performed. The present study results demonstrate that, EPIT in aptamer treated groups had a significant increase of IFN-γ, TGF-β, and IL-10 concentrations and a significant decrease of IgE, IL-4, and IL-17a concentrations as well as NALF infiltrated immune cell count compared to the non-targeted ones. In addition, SPPs led to more significant improvement of immunoregulatory parameters, especially IL-10 cytokine. Accordingly, the targeted-GNPs with DC-specific aptamers could act as an efficient approach for the improvement of EPIT efficacy compared to the free allergen. Moreover, the application of SPPs might be considered as a useful tool in achieving a successful EPIT with lower doses of allergen at a shorter duration of the treatment.

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.

Novel findings in immunopathophysiology of chronic rhinosinusitis and their role in a model of precision medicine

Our understanding of the pathophysiology of chronic rhinosinusitis (CRS) is continuously evolving. The traditional description of CRS in terms of two phenotypes based on the presence or absence of nasal polyps belies the underlying intricate immunopathophysiological processes responsible for this condition. CRS is being increasingly recognized as a disease spectrum encompassing a range of inflammatory states in the sinonasal cavity, with non-type 2 inflammatory disease on one end, type 2 inflammatory, eosinophil-heavy disease on the other and an overlap of both in different proportions in between. Abundance in research on the immune mechanisms of CRS has revealed various new endotypes that hold promise as biomarkers for the development of targeted therapies in severe, uncontrolled CRS. The introduction of precision medicine to manage this chronic, complex condition is a step forward in providing individualized care for all patients with CRS. In this review, the latest research on the pathophysiology of CRS with a focus on potential novel biomarkers and treatment options over the last 2 years are summarized and integrated into a suggested model of precision medicine in CRS.

Allergen immunotherapy: what is the added value of real-world evidence from retrospective claims database studies?

Introduction: Randomized controlled trials (RCTs) show that allergen immunotherapy (AIT) has proven long-term efficacy in patients with allergic rhinitis (AR). However, RCTs have limited generalizability and there is growing recognition that real-world evidence (RWE) is necessary to provide complementary data to those of RCTs, and corroborate their findings. Until recently, data from the real-world setting investigating the benefits of AIT for the treatment of patients with grass and birch pollen-associated AR were sparse, but new retrospective claims database studies from France and Germany have confirmed the sustained benefits of grass and birch pollen AIT in terms of significantly reduced progression of AR and asthma, and a significantly decreased risk of new-onset asthma.Areas covered: Here, we review the value of RWE used alongside data from traditional RCTs, and its potential strengths and limitations, and summarize the findings of the recent RWE studies investigating the benefits of AIT for the management of patients with grass and birch pollen-associated AR.Expert opinion: There is growing recognition of the necessity and value of RWE as a complement to data acquired in RCTs, to better understand the effects of AIT treatments in a broader, more representative patient population, and to help guide clinical decision-making.

Recent developments and highlights in immune monitoring of allergen immunotherapy

Allergic diseases are the most common chronic immune-mediated disorders and can manifest with an enormous diversity in clinical severity and symptoms. Underlying mechanisms for the adverse immune response to allergens and its downregulation by treatment are still being revealed. As a result, there have been, and still are, major challenges in diagnosis, prediction of disease progression/evolution and treatment. Currently, the only corrective treatment available is allergen immunotherapy (AIT). AIT modifies the immune response through long-term repeated exposure to defined doses of allergen. However, as the treatment usually needs to be continued for several years to be effective, and can be accompanied by adverse reactions, many patients face difficulties completing their schedule. Long-term therapy also potentially incurs high costs. Therefore, there is a great need for objective markers to predict or to monitor individual patient's beneficial changes in immune response during therapy so that efficacy can be identified as early as possible. In this review, we specifically address recent technical developments that have generated new insights into allergic disease pathogenesis, and how these could potentially be translated into routine laboratory assays for disease monitoring during AIT that are relatively inexpensive, robust and scalable.

Perspectives in allergen immunotherapy: 2019 and beyond

The seventh "Future of the Allergists and Specific Immunotherapy (FASIT)" workshop held in 2019 provided a platform for global experts from academia, allergy clinics, regulatory authorities and industry to review current developments in the field of allergen immunotherapy (AIT). Key domains of the meeting included the following: (a) Biomarkers for AIT and allergic asthma; (b) visions for the future of AIT; (c) progress and data for AIT in asthma and the updates of GINA and EAACI Asthma Guidelines (separated for house dust mite SCIT, SLIT tablets and SLIT drops; patient populations) including a review of clinically relevant endpoints in AIT studies in asthma; (d) regulatory prerequisites such as the "Therapy Allergen Ordinance" in Germany; (e) optimization of trial design in AIT clinical research; (f) challenges planning and conducting phase III (field) studies and the future role of Allergen Exposure Chambers (AEC) in AIT product development from the regulatory point of view. We report a summary of panel discussions of all six domains and highlight unmet needs and possible solutions for the future.

Highlights of Novel Vaccination Strategies in Allergen Immunotherapy

Increasing safety while maintaining or even augmenting efficiency are the main goals of research for novel vaccine development and improvement of treatment schemes in allergen immunotherapy (AIT). To increase the efficacy of AIT, allergens have been coupled to innate immunostimulatory substances and new adjuvants have been introduced. Allergens have been modified to increase their uptake and presentation. Hypoallergenic molecules have been developed to improve the safety profile of the vaccines. Administration of recombinant IgG4 antibodies is a new, quick, passive immunization strategy with remarkable efficiency. Results of some current investigations aiming at further improvement of AIT vaccines have been summarized.

Allergen immunotherapy in asthma: current evidence

Background: Allergic asthma is the predominant phenotype in clinical practice. Allergen immunotherapy is the only curative and specific approach for the treatment of allergies with clinical benefits for several years after its discontinuation. Despite advances, the use of allergen immunotherapy in allergic asthma is still suboptimal and controversial.Objective: The purpose of this article is to review the published data about the impact of allergen immunotherapy with the most commonly used allergen extracts on allergic asthma outcomes, including both clinical parameters and patients' subjective experience (quality of life).Methods: As data sources several databases were used, including PubMed, Scopus, Web of Science (2002-2019) and search in English and Spanish languages was performed using the following terms: "allergen immunotherapy" and "asthma" in combination with "house dust mite", "birch pollen", "grass pollen", "olive tree pollen", "molds", "pets" and "asthma quality of life". Randomised control trials and meta-analysis from reviewed publications were selected.Results: Emerging data relating to the positive impact on asthma outcomes of allergen immunotherapy allows the addition of this treatment as a therapeutic option in mild to moderate asthmatics sensitized to house dust mite and pollens. Limited data are available for patients sensitized to molds and pets, as well in severe allergic asthma population.Conclusion: Allergen immunotherapy remains a potential therapeutic option for some patients with allergic asthma. Further research is needed to define the optimal period of treatment, the possible therapeutic role in the treatment of severe allergic asthma, and the cost-effectiveness of allergen immunotherapy in asthmatic patients.

Advances in allergen immunotherapy as a treatment of asthma

Introduction: Specific immunotherapy is the only treatment acting on causes and not only on symptoms of respiratory allergy. It was first introduced as subcutaneous immunotherapy (SCIT) with the aim to induce immunological tolerance to the administered allergen(s). In the 1980s, sublingual immunotherapy (SLIT) was developed, mainly to improve the safety, which was a critical issue at that time.Areas covered: This article reviews the available literature, including a large number of randomized controlled trials, meta-analyses, and real-life studies as well, on the outcomes of SCIT and SLIT concerning the treatment critical issues of the two routes, that are efficacy, safety, cost-effectiveness, and compliance to treatment.Expert opinion: SCIT and SLIT are similarly effective in treating patients with respiratory allergy, providing, based on the induction of typical changes in the immunologic response, an early control of symptoms that steadily increases during the treatment and, once reached the recommended duration of 3 years, continues to work after stopping. This outcome is the major factor influencing the economic advantage of SCIT and SLIT over drug treatment.

Prospective comparison of a nonmodified and a modified mite extract for immunotherapy in children and adolescents

Aim: This prospective study compares nonmodified and modified house dust mite extracts for allergen immunotherapy (AIT) in pediatric patients with allergic asthma. Materials & methods: Total 95 patients underwent bronchial allergen provocation (BAP). AIT was recommended to 62 patients. Complete datasets of 54 subjects were obtained. Primary aim was the comparison of treatment success defined by BAP between two extracts after 1 year. Secondary parameters were laboratory parameters and clinical symptoms. Results: Significant improvement (p < 0.001) was measured by BAP in both treatment groups. No change was seen in the controls. Both extracts exerted comparable effects on all parameters. Conclusion: After 1 year of AIT, the extracts were equally efficient, with significant improvements in 70.0% (nonmodified) and 72.2% (modified) of patients.

Precision medicine and phenotypes, endotypes, genotypes, regiotypes, and theratypes of allergic diseases

A rapidly developing paradigm for modern health care is a proactive and individualized response to patients' symptoms, combining precision diagnosis and personalized treatment. Precision medicine is becoming an overarching medical discipline that will require a better understanding of biomarkers, phenotypes, endotypes, genotypes, regiotypes, and theratypes of diseases. The 100-year-old personalized allergen-specific management of allergic diseases has particularly contributed to early awareness in precision medicine. Polyomics, big data, and systems biology have demonstrated a profound complexity and dynamic variability in allergic disease between individuals, as well as between regions. Escalating health care costs together with questionable efficacy of the current management of allergic diseases facilitated the emergence of the endotype-driven approach. We describe here a precision medicine approach that stratifies patients based on disease mechanisms to optimize management of allergic diseases.

Real-world benefits of allergen immunotherapy for birch pollen-associated allergic rhinitis and asthma

BACKGROUND

Real-world evidence is sparse on the benefits of allergen immunotherapy [AIT; subcutaneous/sublingual immunotherapy (SCIT/SLIT)], the only disease-modifying intervention for allergic rhinitis (AR) with long-term efficacy. This real-life study evaluated the effect of six AITs (native pollen SLIT/SCIT, four allergoid SCITs) vs symptomatic medication use, on AR symptoms and asthma symptoms/onset, in patients with birch pollen-associated AR and/or asthma.

METHODS

In this retrospective cohort analysis of a German longitudinal prescription database, AIT patients received ≥2 successive seasonal treatment cycles; non-AIT patients had ≥3 AR prescriptions in three seasons or previous month. Patients were matched for: index year, age, gender, main indication at index, number of seasonal cycles within treatment period, baseline AR/asthma treatment prescriptions. Multiple regression analysis compared prescription data in AIT and non-AIT groups as proxy for clinical status/disease progression.

RESULTS

Up to 6 years of follow-up, significantly more AIT (65.4%) vs non-AIT (47.4%) patients were AR medication-free; odds ratio (OR) [95% confidence interval (CI)]: 0.51 [(0.48-0.54); P < 0.001] (28.6% covariate-adjusted reduction vs non-AIT; P < 0.001), and significantly more AIT (49.1%) vs non-AIT (35.1%) patients were asthma medication-free [OR (95% CI): 0.59 (0.55-0.65); P < 0.001] (32% reduction vs non-AIT; P < 0.001), or reduced existing asthma medication use (32% covariate-adjusted reduction vs non-AIT; P < 0.001). During treatment, new-onset asthma risk was significantly reduced in the AIT vs non-AIT group (OR: 0.83; P = 0.001).

CONCLUSIONS

Birch pollen AIT demonstrated real-world benefits up to 6 years post-treatment cessation through significantly reduced AR and asthma medication intake, and significantly decreased risk of new-onset asthma medication use on-treatment.

Stepwise approach towards adoption of allergen immunotherapy for allergic rhinitis and asthma patients in daily practice in Belgium: a BelSACI-Abeforcal-EUFOREA statement

Allergic rhinitis (AR) affects 23–30% of the European population with equal prevalence reported in Belgium. Despite guidelines on the correct use of effective treatment, up to 40% of AR patients remain uncontrolled. Allergen immunotherapy (AIT) has been shown to improve the level of control up to 84% of patients being controlled by AIT. Recently, new guidelines for AIT have been published, supporting the clinical evidence for effectiveness of various subcutaneous and sublingual products for AIT in patients who are allergic to airborne allergens. AIT in AR patients not only reduces nasal and/or ocular symptoms but also induces tolerance and has preventive potential. Adoption of AIT into daily clinical practice in Belgium and other European countries is hampered primarily by reimbursement issues of each of the single products but also by several patient- and physician-related factors. Patients need to be better informed about the effectiveness of AIT and the different routes of administration of AIT. Physicians dealing with AR patients should inform patients on tolerance-inducing effects of AIT and are in the need of a harmonized and practical guide that supports them in selecting eligible patients for AIT, in choosing evidence-based AIT products and in following treatment protocols with proven efficacy. Therefore, a stepwise and holistic approach is needed for better adoption of AIT in the real-life setting in Belgium.

Recent developments and highlights in allergen immunotherapy

Allergen immunotherapy (AIT) is the only disease-modifying treatment option for patients with IgE-mediated inhalant allergies. Though used in clinical practice for more than 100 years, most innovations in AIT efficacy and safety have been developed in the last two decades. This expert review aimed to highlight the recent progress in AIT for both application routes, the sublingual (SLIT) and subcutaneous (SCIT) forms. As such, it covers recent aspects regarding efficacy and safety in clinical trials and real-life data and outlines new concepts in consensus and position papers as well as in guidelines for AIT. Potential clinical and nonclinical biomarkers are discussed. This review also focuses on potential future perspectives in AIT, such as alternative application routes, immune-modulating adjuvants, and recombinant vaccines. In conclusion, this state of the art review provides a comprehensive overview of AIT and highlights unmet needs for the future.