Allergen immunotherapy: a new semantic framework from the European Academy of Allergy and Clinical Immunology/American Academy of Allergy, Asthma and Immunology/PRACTALL consensus report

lncRNA FR215775 Regulates Th2 Differentiation in Murine Allergic Rhinitis

To identify the effect of long noncoding RNA (lncRNA) FR215775 in regulating CD4+ T cells on murine models of allergic rhinitis (AR), the expression of lncRNA FR215775 in primary Th2 cells was detected through qRT-PCR. After knocking down the expression of lncRNA FR215775 via Sh-FR215775-Ads, Cell Counting Kit-8, cytometric bead array, and fluorescence-activated cell sorting were performed to determine its functions in vitro. Moreover, lncRNA FR215775-silencing or nonsilencing cells were injected intravenously into AR mice. Then, hematoxylin and eosin, Alcian blue-periodic acid Schiff, and toluidine blue staining were performed, and the levels of IL-2, IL-4, IL-5, IL-6, IL-10, IL-17A, IFN-γ, and TNF in the AR mice were also determined. We found that the expression of lncRNA FR215775 was specifically higher in the murine primary Th2 cells. After the knockdown of lncRNA FR215775, the proliferation of CD4+ T cells was inhibited, and the expressions of IL-4 and IL-5 in the cell culture supernatant were significantly decreased (P < 0.001), along with the percentage of Th2 cells (P < 0.05). The lncRNA FR215775-silencing AR group showed less serious allergic symptoms and a low level of ovalbumin-specific immunoglobulin E (P < 0.01). Meanwhile, the eosinophilia inflammation, goblet cell hyperplasia, and mast cell inflammation in the nasal mucosa all decreased, which indicated attenuated allergic inflammation in the lncRNA FR215775-silencing AR group. In addition, the Th2-related cytokines IL-4 and IL-5 were downregulated in the serum and nasal lavage fluid of this group (P < 0.01). In conclusion, lncRNA FR215775 may play a vital role in the function and differentiation of Th2 cells, which may encourage allergic inflammation. These results may provide significant insights into AR pathogenesis and offer new treatment targets for alleviating AR.

Serum Periostin as a Biomarker for Predicting Clinical Response to House Dust Mite Sublingual Immunotherapy in Allergic Rhinitis

BACKGROUND

House dust mite (HDM) sublingual immunotherapy (SLIT) has proven to be effective for allergic rhinitis (AR), but its efficacy varies among patients. No candidate biomarkers for prediction of response to SLIT are available. Periostin, a matricellular protein, is involved in pathophysiology of AR, and its serum levels reflect airway allergic inflammation.

OBJECTIVE

To evaluate the relationship between serum periostin levels and current rhinitis control before and after standardized quality (SQ)-HDM SLIT, and to investigate the role of periostin in predicting clinical response.

METHODS

One hundred eleven subjects with HDM-induced AR were randomized to receive either SLIT plus pharmacotherapy or pharmacotherapy alone, for 48 weeks. At enrollment and the end of study, clinical characteristics and biomarkers that included serum periostin, serum HDM-specific IgE (s-IgE), total IgE, blood eosinophil counts, and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) were measured. The association between clinical indices or biomarkers and clinical response to SLIT was analyzed.

RESULTS

A response to SLIT was recorded in 64% (32 of 50) patients. High serum periostin levels (>30.2 ng/mL) were associated with an effective response to SLIT, and the magnitude of RQLQ improvement was correlated with the level of serum periostin. The sensitivity and specificity based on receiver operating characteristic analysis for periostin were higher than those of s-IgE. Multivariate regression analysis showed that serum periostin was an independent factor for SLIT responders.

CONCLUSIONS

Serum periostin appears to be a useful biomarker for predicting the response to SQ-HDM SLIT in patients with AR.

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.

Differential DNA methylation profiles of peripheral blood mononuclear cells in allergic asthmatic children following dust mite immunotherapy

BACKGROUND/PURPOSE

Allergen-specific immunotherapy (SIT) is now considered curative to allergic diseases such as asthma. Mechanistically, our previous work showed DNA hypermethylation of cytokine genes, in T-helper cells, in allergic asthmatic children treated with allergen-SIT. In this study, we extended to work to assess possible changes in the DNA methylomes of peripheral blood mononuclear cells (PBMCs), isolated from mite allergen-SIT asthmatic children, to explore further the underlying methylation changes.

METHODS

Thirteen allergic asthmatic children who received Der p-SIT, 12 non-SIT allergic asthmatic controls, and 12 healthy controls were enrolled. Bisulfite-converted DNA from Der p-stimulated PBMCs was analyzed using Human Methylation 450 k BeadChip. Pyrosequencing and quantitative real-time PCR were used to validate the DNA methylation levels and the gene expression of individual samples.

RESULTS

We identified 108 significantly differentially methylated regions (DMRs) unique to Der p-treated PBMCs, with 53 probes linked to demethylated DMRs, and 55 probes linked to methylated DMRs. Three associated genes (BCL6, HSPG2, and HSP90AA1), of selected DMRs, were subjected to bisulfite pyrosequencing. Of these, BCL6 showed significant hypomethylation, while HSPG2 and HSP90AA1 were hypermethylated in SIT group, compared to the AA group. Furthermore, SIT group had significantly higher gene expression of BCL6 and lower gene expression of HSPG2. KEGG pathway analysis further revealed DMR genes involved in ECM-receptor interactions, asthma, and antigen processing and presentation pathways.

CONCLUSIONS

Several DNA regions showed DNA methylation altered by Der p specific immunotherapy, indicating desensitization-associated methylomes. Genes belonging to these SIT-altered pathways may represent therapeutic targets for better clinical management of asthma.

The Use of Biomarkers to Predict Aero-Allergen and Food Immunotherapy Responses

The incidence of allergic conditions has continued to rise over the past several decades, with a growing body of research dedicated toward the treatment of such conditions. By driving a complex range of changes in the underlying immune response, immunotherapy is the only therapy that modulates the immune system with long-term effects and is presently utilized for the treatment of several atopic conditions. Recent efforts have focused on identifying biomarkers associated with these changes that may be of use in predicting patients with the highest likelihood of positive clinical outcomes during allergen immunotherapy (AIT), providing guidance regarding AIT discontinuation, and predicting symptomatic relapse and the need for booster AIT after therapy. The identification of such biomarkers in food allergy has the additional benefit of replacing oral food challenges, which are presently the gold standard for diagnosing food allergies. While several markers have shown early promise, research has yet to identify a marker that can invariably predict clinical response to AIT. Skin prick testing (SPT) and specific IgE have commonly been used as inclusion criteria for the initiation of AIT and prediction of reactions during subsequent allergen challenge; however, existing data suggests that changes in these markers are not always associated with clinical improvement and can be widely variable, reducing their utility in predicting clinical response. Similar findings have been described for the use of allergen-specific functional IgG4 antibodies, basophil activation and histamine release, and type 2 innate lymphoid cells. There appears to be a promising association between changes in the expression of dendritic cell-associated markers, as well as the use of DNA promoter region methylation patterns in the prediction of allergy status following therapy. The cellular and molecular changes brought about by immunotherapy are still under investigation, but major strides in our understanding are being made.

Preparation allergenic pollen extracts; the points should be considered to make high-quality products

Atopic diseases have an increasing trend worldwide during the last two decades. Determining the main cause of allergic diseases, allergens, is the first step in managing and improving the issue, usually is done by Skin Prick tests (SPTs). Having allergenic extract in high quality is desired to perform a reliable SPT. Several parameters of extracts are considered including composition, stability, potency, preservation conditions, and unit definition. In this review, these factors have been explained pointing to factors might have profitable points or harmful drawback in the quality of allergen extracts.

IgE Test in Secretions of Patients with Respiratory Allergy

PURPOSE OF REVIEW

IgE is a key player in multiple inflammatory airway diseases. Ample literature demonstrates its presence in mucosa of patients with allergic rhinitis (AR), local allergic rhinitis (LAR), asthma, or chronic rhinosinusitis with nasal polyposis (CRSwNP).

RECENT FINDINGS

Current evidence shows that high-affinity IgE in blood stream of allergic individuals derives mainly from the mucosae. Also, mucosal synthesis of IgE can occur in the absence of systemic atopy, and may be relevant in atopic and non-atopic phenotypes of rhinitis as demonstrated in LAR. Specific IgE (sIgE) detection varies depending on technique used for sample collection and its measurement. sIgE detection is highly specific for diagnosis of LAR. Moreover, measurement of sIgE in secretions could be useful in monitoring response to allergen-specific immunotherapy in both AR and LAR phenotypes. This review will focus on recent developments in the role of IgE in respiratory diseases, and the clinical implications of its measurement in secretions.

Biomarkers of immunotherapy response in patients with allergic rhinitis

INTRODUCTION

Allergen immunotherapy represents the only disease-modifying therapy available for immunoglobulin E-mediated diseases such as allergic rhinitis and asthma. Allergen immunotherapy induces allergen tolerance by interfering with the immune-pathogenic mechanisms of the allergic response and is potentially able to provide long-term relief of symptoms of allergic rhinitis and asthma and alter the natural course of allergic diseases. Areas covered: Since allergen immunotherapy (AIT) is actually considered an individualized treatment on patient's clinical and immunological profile, the identification of specific biomarkers, which may guide diagnosis, management, and predict response to AIT treatment in allergic rhinitis (AR) patients, is essential and is currently an active field of research. Expert commentary: The identification and validation of biomarkers of successful AIT for AR is an urgent need to definitively establish the role of AIT as a therapeutic tool of personalized medicine.

Mechanisms of allergen immunotherapy for inhaled allergens and predictive biomarkers

Allergen immunotherapy is effective in patients with IgE-dependent allergic rhinitis and asthma. When immunotherapy is given continuously for 3 years, there is persistent clinical benefit for several years after its discontinuation. This disease-modifying effect is both antigen-specific and antigen-driven. Clinical improvement is accompanied by decreases in numbers of effector cells in target organs, including mast cells, basophils, eosinophils, and type 2 innate lymphoid cells. Immunotherapy results in the production of blocking IgG/IgG₄ antibodies that can inhibit IgE-dependent activation mediated through both high-affinity IgE receptors (FcεRI) on mast cells and basophils and low-affinity IgE receptors (FcεRII) on B cells. Suppression of T_H2 immunity can occur as a consequence of either deletion or anergy of antigen-specific T cells; induction of antigen-specific regulatory T cells; or immune deviation in favor of T_H1 responses. It is not clear whether the altered long-term memory resides within the T-cell or the B-cell compartment. Recent data highlight the role of IL-10-producing regulatory B cells and "protective" antibodies that likely contribute to long-term tolerance. Understanding mechanisms underlying induction and persistence of tolerance should identify predictive biomarkers of clinical response and discover novel and more effective strategies for immunotherapy.

Biomarkers for monitoring clinical efficacy of allergen immunotherapy for allergic rhinoconjunctivitis and allergic asthma: an EAACI Position Paper

BACKGROUND

Allergen immunotherapy (AIT) is an effective treatment for allergic rhinoconjunctivitis (AR) with or without asthma. It is important to note that due to the complex interaction between patient, allergy triggers, symptomatology and vaccines used for AIT, some patients do not respond optimally to the treatment. Furthermore, there are no validated or generally accepted candidate biomarkers that are predictive of the clinical response to AIT. Clinical management of patients receiving AIT and efficacy in randomised controlled trials for drug development could be enhanced by predictive biomarkers.

METHOD

The EAACI taskforce reviewed all candidate biomarkers used in clinical trials of AR patients with/without asthma in a literature review. Biomarkers were grouped into seven domains: (i) IgE (total IgE, specific IgE and sIgE/Total IgE ratio), (ii) IgG-subclasses (sIgG1, sIgG4 including SIgE/IgG4 ratio), (iii) Serum inhibitory activity for IgE (IgE-FAB and IgE-BF), (iv) Basophil activation, (v) Cytokines and Chemokines, (vi) Cellular markers (T regulatory cells, B regulatory cells and dendritic cells) and (vii) In vivo biomarkers (including provocation tests?).

RESULTS

All biomarkers were reviewed in the light of their potential advantages as well as their respective drawbacks. Unmet needs and specific recommendations on all seven domains were addressed.

CONCLUSIONS

It is recommended to explore the use of allergen-specific IgG4 as a biomarker for compliance. sIgE/tIgE and IgE-FAB are considered as potential surrogate candidate biomarkers. Cytokine/chemokines and cellular reponses provided insight into the mechanisms of AIT. More studies for confirmation and interpretation of the possible association with the clinical response to AIT are needed.

[Immunological mechanisms of allergen-specific immunotherapy]

Allergen-specific immunotherapy is accompanied by multiple changes on the cellular and humoral level. A shift of Th2 immune responses towards immune responses of the Th1 type, which goes along with an increase of regulatory T cells and B cells, IL-10 as well as reduction of effector cells and eosinophils in the tissue, combined with lower IgE production in favor of higher IgG4 production, are regarded as key mechanisms of allergen-specific immunotherapy . A better understanding of immunologic pathways of specific immunotherapy would be essential for the improvement of this therapy as well as for the development of reliable biomarkers capable to monitor therapeutic responses as well as compliance of the patients.

Allergy immunotherapy across the life cycle to promote active and healthy ageing: from research to policies: An AIRWAYS Integrated Care Pathways (ICPs) programme item (Action Plan B3 of the European Innovation Partnership on active and healthy ageing) and the Global Alliance against Chronic Respiratory Diseases (GARD), a World Health Organization GARD research demonstration project

Allergic diseases often occur early in life and persist throughout life. This life-course perspective should be considered in allergen immunotherapy. In particular it is essential to understand whether this al treatment may be used in old age adults. The current paper was developed by a working group of AIRWAYS integrated care pathways for airways diseases, the model of chronic respiratory diseases of the European Innovation Partnership on active and healthy ageing (DG CONNECT and DG Santé). It considered (1) the political background, (2) the rationale for allergen immunotherapy across the life cycle, (3) the unmet needs for the treatment, in particular in preschool children and old age adults, (4) the strategic framework and the practical approach to synergize current initiatives in allergen immunotherapy, its mechanisms and the concept of active and healthy ageing.

Evidence in immunotherapy for paediatric respiratory allergy: Advances and recommendations

Allergic respiratory diseases are major health problems in paediatric population due their high level of prevalence and chronicity, and to their relevance in the costs and quality of life. One of the most important risk factors for the development of airway diseases in children and adolescents is atopy. The mainstays for the treatment of these diseases are avoiding allergens, controlling symptoms, and preventing them through sustained desensitization by allergen immunotherapy (AIT). AIT is a treatment option that consists in the administration of increasing amounts of allergens to modify the biological response to them, inducing long-term tolerance even after treatment has ended. This treatment approach has shown to decrease symptoms and improve quality of life, becoming cost effective for a large number of patients. In addition, it is considered the only treatment that can influence the natural course of the disease by targeting the cause of the allergic inflammatory response. The aim of this publication is to reflect the advances of AIT in the diagnosis and treatment of allergic respiratory diseases in children and adolescents reviewing articles published since 2000, establishing evidence categories to support the strength of the recommendations based on evidence. The first part of the article covers the prerequisite issues to understand how AIT is effective, such as the correct etiologic and clinical diagnosis of allergic respiratory diseases. Following this, the article outlines the advancements in understanding the mechanisms by which AIT achieve immune tolerance to allergens. Administration routes, treatment regimens, dose and duration, efficacy, safety, and factors associated with adherence are also reviewed. Finally, the article reviews future advances in the research of AIT.

Applications and mechanisms of immunotherapy in allergic rhinitis and asthma

Clinical and immunologic tolerance are hallmarks of successful allergen immunotherapy (AIT). Clinical benefits such as reduced symptoms, pharmacotherapy intake and improvement of quality of life persist following cessation of treatment. Successful AIT is associated with suppression of allergic inflammatory cells such as mast cells, eosinophils and basophils in target organs. Furthermore, AIT down-regulates type 2 innate lymphoid cells and allergen-specific type 2 T-helper (Th2) cells. The immunologic tolerant state following AIT is associated with the induction of distinct phenotypes of regulatory T-cells (T-regs) including interleukin (IL)-10-, IL-35- and transforming growth factor (TGF)-β- producing T-regs and FoxP3⁺ T-regs. B-cell responses, including the induction of IL-10⁺ regulatory B-cells (B-regs) and the production of IgG4-associated blocking antibodies are also induced following successful AIT. These events are associated with the suppression of antigen-specific Th2 responses and delayed immune deviation in favour of Th1 type responses. Insight into the mechanisms of AIT has allowed identification of novel biomarkers with potential to predict the clinical response to AIT and also novel therapeutic strategies for more effective and safer AIT.

Allergic Rhinitis: Mechanisms and Treatment

The prevalence of allergic rhinitis (AR) has been estimated at 10% to 40%, and its economic burden is substantial. AR patients develop specific immunoglobulin E (IgE) antibody responses to indoor and outdoor environmental allergens with exposure over time. These specific IgE antibodies bind to high-affinity IgE receptors on mast cells and basophils. Key outcome measures of therapeutic interventions include rhinitis symptom control, rescue medication requirements, and quality-of-life measures. A comprehensive multiple modality treatment plan customized to the individual patient can optimize outcomes.

Revisiting Desensitization and Allergen Immunotherapy Concepts for the International Classification of Diseases (ICD)-11

Allergy and hypersensitivity intervention management procedures, such as desensitization and/or tolerance induction and immunotherapy, have not been pondered up to now in the content of International Classification of Diseases (ICD) context because the focus has been on prioritizing the condition implementations. Tremendous efforts have been devoted to implementing allergic and hypersensitivity conditions in the forthcoming ICD-11. However, we consider that it is crucial now to have nomenclature and classification universally accepted for these procedures to be able to provide scientifically consistent proposals into the new ICD-11 platform for the best practice parameters of our specialty. With the aim of promoting a harmonized comprehension and aligning it with the ICD-11 revision, we have reviewed the definitions and concepts currently used for desensitization and/or tolerance induction and immunotherapy. We strongly believe that this review is a key instrument to support the allergy specialty identity into the ICD-11 framework and serves as a platform to perform positive quality improvement in clinical practice.

Allergy immunotherapy: the future of allergy treatment

Allergic respiratory disease represents a significant and expanding health problem worldwide. Allergic symptoms, such as asthma and hay fever, cause sleep impairment and reduce school and work performance. The cost to society is substantial. Allergen avoidance and pharmacotherapy cannot control the disease. Only allergy immunotherapy has disease-modifying potential and should be included in optimal treatment strategies. Allergy immunotherapy was first administered as subcutaneous injections and has been practiced for the past 100 years or so. Recently, tablet-based sublingual allergy immunotherapy (SLIT) was introduced with comprehensive clinical documentation. SLIT tablets represent a more patient-friendly concept because they can be used for self-treatment at home.

Phenotypes and endotypes of rhinitis and their impact on management: a PRACTALL report

Rhinitis is an umbrella term that encompasses many different subtypes, several of which still elude complete characterization. The concept of phenotyping, being the definition of disease subtypes on the basis of clinical presentation, has been well established in the last decade. Classification of rhinitis entities on the basis of phenotypes has facilitated their characterization and has helped practicing clinicians to efficiently approach rhinitis patients. Recently, the concept of endotypes, that is, the definition of disease subtypes on the basis of underlying pathophysiology, has emerged. Phenotypes/endotypes are dynamic, overlapping, and may evolve into one another, thus rendering clear-cut definitions difficult. Nevertheless, a phenotype-/endotype-based classification approach could lead toward the application of stratified and personalized medicine in the rhinitis field. In this PRACTALL document, rhinitis phenotypes and endotypes are described, and rhinitis diagnosis and management approaches focusing on those phenotypes/endotypes are presented and discussed. We emphasize the concept of control-based management, which transcends all rhinitis subtypes.

[Specific immunotherapy]

SCIT (subcutaneous immunotherapy) and SLIT (sublingual immunotherapy) are the only routinely available therapies, which modify allergic diseases sustainably. The ongoing reduction of symptoms and the lower need of symptomatic medication are able to improve the quality of life over a long period of time. However, allergic patients are underprovided due to low use of SIT (specific immunotherapy). After thorough diagnostic workup, the indication has to be checked carefully especially in patients with allergic rhinitis and allergic asthma, to insure that SIT is standard therapy. Allergen extracts are manufacturer-specific preparations, therefore their effects cannot be compared directly, just as SCIT and SLIT efficacy cannot be compared directly. In general, preparations with proven efficacy and safety profile should be preferred. Allergens listed in the TAV (Therapeutic Allergen Regulation) fulfill these requirements. However, it is important to ensure adherence for 3 years of therapy, independent of the route of application. SIT has proven socioeconomic benefit already after a short time of therapy.

The contribution of biotechnology toward progress in diagnosis, management, and treatment of allergic diseases

'Biotechnology' has been intuitively used by humans since thousands of years for the production of foods, beverages, and drugs based on the experience without any scientific background. However, the golden era of this discipline emerged only during the second half of the last century. Incredible progresses have been achieved on all fields starting from the industrialization of the production of foods to the discovery of antibiotics, the decipherment of the genetic code, and rational approaches to understand and define the status we now call 'healthy'. The extremely complex interactions between genetic background, life style, and environmental factors influencing our continuously increasing life span have become more and more evident and steadily generate new questions which are only partly answered. Here, we try to summarize the contribution of biotechnology to our understanding, control, and cure of IgE-mediated allergic diseases. We are aware that a review of such a vast topic can never cover all aspects of the progress achieved in the different fields.

Mechanisms of allergen-specific immunotherapy: multiple suppressor factors at work in immune tolerance to allergens

Allergen-specific immunotherapy (AIT) has been used for more than 100 years as a desensitizing therapy for IgE-mediated allergic diseases and represents a potentially curative way of treatment. The mechanisms of action of AIT include the induction of very early desensitization of mast cells and basophils; generation of regulatory T and regulatory B (Breg) cell responses; regulation of IgE and IgG4; decreases in numbers and activity of eosinophils and mast cells in mucosal allergic tissues; and decreases in the activity of basophils in circulation. Skewing of allergen-specific effector T and effector B cells to a regulatory phenotype appears as a key event in the course of AIT and normal immune response to allergens. Recently, inducible IL-10-secreting Breg cells were also demonstrated to contribute to allergen tolerance through suppression of effector T cells and selective induction of IgG4 isotype antibodies. Allergen-specific regulatory T and Breg cells orchestrate a general immunoregulatory activity, which can be summarized as suppression of cytokines from inflammatory dendritic cells; suppression of effector TH1, TH2, and TH17 cells; suppression of allergen-specific IgE and induction of IgG4; and suppression of migration of mast cells, basophils, eosinophils, and effector T cells to tissues. A detailed knowledge of the mechanisms of AIT is not only important in designing the prevention and treatment of allergic diseases but might also find applications in the treatment of autoimmune diseases, organ transplantation, chronic infection, and cancer.

Immunotherapy in allergy and cellular tests: state of art

The basophil activation test (BAT) is an in vitro assay where the activation of basophils upon exposure to various IgE-challenging molecules is measured by flow cytometry. It is a cellular test able to investigate basophil behavior during allergy and allergy immunotherapy. A panoply of critical issues and suggestive advances have rendered this assay a promising yet puzzling tool to endeavor a full comprehension of innate immunity of allergy desensitization and manage allergen or monoclonal anti-IgE therapy. In this review a brief state of art of BAT in immunotherapy is described focusing onto the analytical issue pertaining BAT performance in allergy specific therapy.

Magnitude of efficacy measurements in grass allergy immunotherapy trials is highly dependent on pollen exposure

Background

The objective was to evaluate the association between grass pollen exposure, allergy symptoms and impact on measured treatment effect after grass sublingual immunotherapy (SLIT)-tablet treatment.

Methods

The association between grass pollen counts and total combined rhinoconjunctivitis symptom and medication score (TCS) was based on a post hoc analysis of data collected over six trials and seven grass pollen seasons across North America and Europe, including 2363 subjects treated with grass SLIT-tablet or placebo. Daily pollen counts were obtained from centralized pollen databases. The effect of treatment on the relationship between the TCS and pollen counts was investigated, and the relative difference between grass SLIT-tablet and placebo as a function of average grass pollen counts was modelled by linear regression.

Results

The magnitude of treatment effect based on TCS was greater with higher pollen exposure (P < 0.001). The relative treatment effect in terms of TCS for each trial was correlated with the average grass pollen exposure during the first period of the season, with predicted reduction in TCS = 12% + 0.35% × pollen count (slope significantly different from 0, P = 0.003; R² = 0.66). Corresponding correlations to the entire grass pollen season and to the peak season were equally good, whereas there was a poor correlation between difference in measured efficacy and pollen exposure during the last part of the season.

Conclusions

In seasonal allergy trials with grass SLIT-tablet, the observed treatment effect is highly dependent on pollen exposure with the magnitude being greater with higher pollen exposure. This is an important relationship to consider when interpreting individual clinical trial results.

Sublingual immunotherapy: World Allergy Organization position paper 2013 update

We have prepared this document, "Sublingual Immunotherapy: World Allergy Organization Position Paper 2013 Update", according to the evidence-based criteria, revising and updating chapters of the originally published paper, "Sublingual Immunotherapy: World Allergy Organization Position Paper 2009", available at http://www.waojournal.org. Namely, these comprise: "Mechanisms of sublingual immunotherapy;" "Clinical efficacy of sublingual immunotherapy" - reporting all the data of all controlled trials published after 2009; "Safety of sublingual immunotherapy" - with the recently published Grading System for adverse reactions; "Impact of sublingual immunotherapy on the natural history of respiratory allergy" - with the relevant evidences published since 2009; "Efficacy of SLIT in children" - with detailed analysis of all the studies; "Definition of SLIT patient selection" - reporting the criteria for eligibility to sublingual immunotherapy; "The future of immunotherapy in the community care setting"; "Methodology of clinical trials according to the current scientific and regulatory standards"; and "Guideline development: from evidence-based medicine to patients' views" - including the evolution of the methods to make clinical recommendations.Additionally, we have added new chapters to cover a few emerging crucial topics: "Practical aspects of schedules and dosages and counseling for adherence" - which is crucial in clinical practice for all treatments; "Perspectives and new approaches" - including recombinant allergens, adjuvants, modified allergens, and the concept of validity of the single products. Furthermore, "Raising public awareness about sublingual immunotherapy", as a need for our patients, and strategies to increase awareness of allergen immunotherapy (AIT) among patients, the medical community, all healthcare stakeholders, and public opinion, are also reported in detail.

Allergen-Specific Immunotherapy in Asthma

Current asthma therapies can effectively control symptoms and the on-going inflammatory process; however, they do not affect the underlying, dysregulated immune response. Thus, they are limited to blunting the progression of the disease, which relapses on ceasing the treatment. Allergen-specific immunotherapy (AIT) is the only etiology-based treatment capable of disease modification. Recent evidence provided a plausible explanation for its multiple mechanisms inducing both rapid desensitization and long-term allergen-specific immune tolerance, as well as the suppression of allergic inflammation in the affected tissues. Although the current guideline documents give both subcutaneous (SCIT) and sublingual (SLIT) immunotherapy a conditional recommendation in allergic asthma due to the moderate and low quality of evidence, respectively, a growing body of evidence from double-blind, placebo-controlled studies shows that both SLIT and SCIT are effective in reducing symptom scores and medication use, improving quality of life, and inducing favorable changes in specific immunologic markers. Due to the very limited evidence from head-to-head comparative studies and variability of the end-point used in different studies, it is currently not possible to assess superiority of either route of vaccine administration.