Assessment of sublingual immunotherapy efficacy in children with house dust mite-induced allergic asthma optimally controlled by pharmacologic treatment and mite-avoidance measures

Satisfaction, Qol and adherence of patients allergic to dust mites and/or pollens undergoing sublingual immunotherapy

Aim: Sublingual immunotherapy (SLIT) changes history of allergic respiratory disease (ARD). However, adherence is a barrier for optimal outcomes. Patients & methods: In the QUALI study, 859 patients with house-dust mite (HDM) and/or pollen induced ARD uncontrolled with symptomatic treatment and undergoing SLIT for at least 6 months or including one pre-coseason (pollen) were collected. Results & conclusion: SLIT significantly improved allergic rhinoconjunctivitis (ARC) and asthma symptom control, leading to reduced medication, meaningful health-related quality of life gain, improved nasal, ocular and bronchial symptoms and everyday life activities. Patients were highly satisfied and most of them adhered to SLIT, being forgetfulness the main non-adherence motive. SLIT is a quick effective treatment against persistent moderate-to-severe symptoms in ARC and asthma but it should been improve forgetfulness, as non-adherence reason.

Efficacy and safety of house dust mite subcutaneous immunotherapy in polysensitized children with allergic asthma

INTRODUCTION

The aim of this study was to compare the efficacy and safety of 3 years of HDM subcutaneous immunotherapy (HDM-SCIT) in allergic asthma (AA) children with mono- and polysensitized.

METHODS

This was a retrospective observational study, 51 AA children (aged 4-14 years) who had completed 3 years of standardized HDM-SCIT were enrolled in. Based on skin prick tests (SPT) and allergen-specific IgE antibody (sIgE) test results, children were classified into two groups: the monosensitized group (n = 31) and the polysensitized group (n = 20). Total asthma symptoms score (TASS), total medication score (TMS), visual analog scale (VAS) scores, fractional exhaled nitric oxide (FeNO), lung function parameters, and adverse reactions were evaluated before treatment and at 6 months, 1, 2, 3 years of HDM-SCIT.

RESULTS

In terms of effectiveness, compared to baseline, TASS, TMS, VAS, FeNO and lung function parameters were significantly improved in both groups after 3 years of HDM-SCIT (all P < 0.05). The comparison between the two groups showed that efficacy indicators were no statistically significant difference at follow-up time points (all P > 0.05) except PEF%pred at 6 months (P = 0.048). In terms of security, the number of adverse reactions in both groups also no statistical difference between the two groups (all P > 0.05).

CONCLUSION

This study confirmed that no significant difference was observed in the clinical efficacy and safety of HDM-SCIT between mono-and polysensitized children with allergic asthma.

Understanding the Updates in the Asthma Guidelines

Asthma is a chronic inflammatory lung disease that affects millions of Americans, with variable symptoms of bronchospasm and obstruction among individuals over time. The National Heart, Lung, and Blood Institute (NHLBI) published the 2020 Focused Updates to the Asthma Management Guidelines based on the latest research since the 2007 Expert Panel Report-3 (EPR-3). The following article reviews the 21 new recommendations on the six core topics in asthma: use of intermittent inhaled corticosteroids, long-acting muscarinic antagonist therapy, use of the fractional exhaled nitric oxide test in asthma diagnosis and monitoring, indoor allergen mitigation, immunotherapy, and bronchial thermoplasty. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to rate recommendations as strong or conditional based on the evidence. The recommendations were based on systematic reviews of the literature and focused on patient-centered critical outcomes of asthma exacerbations, asthma control, and asthma-related quality of life. Understanding the recommendations with consideration of individual values through shared decision-making may improve asthma outcomes.

Immunotherapy for Asthma

Asthma represents one of the biggest global health concerns with increasing prevalence and influence on global health. Several distinct asthma phenotypes have been identified with one of the most common, earliest recognized, and described being the allergic asthma phenotype, in which allergens trigger asthma through mechanisms involving allergen-specific immunoglobulin E (IgE). Allergen-specific immunotherapy (AIT), in the forms of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT), has been used for many decades as a tool for reducing IgE-mediated sensitization and controlling symptoms of allergic disease, most commonly for allergic rhinitis, and it remains the only currently available disease modifying therapy in atopic patients. AIT has been studied for use in mild to moderate allergic asthma. While the data are often inconsistent, and utilize a multitude of different methods, antigens, and outcome measures, in general, AIT may have several beneficial effects on asthma disease control, quality of life, and requirement for medication. These benefits are notable when immunotherapy is used as an adjunct to pharmacologic treatment in carefully selected and monitored patients with mild to moderate persistent asthma. Patients with severe asthma are excluded from these trials. Importantly, patients with asthma, and in particular severe asthma, may have a higher rate of systemic adverse reactions to SCIT, including anaphylaxis, however, these events are overall rare. Future research in the area is needed to definitively assess the benefit of SCIT and SLIT for patients with asthma, comparing outcomes with different methods, addressing the role of AIT in severe asthma, significance of multiallergen AIT in allergic asthma, and safety concerns in asthma.

Efficacy and Safety of House Dust Mite Sublingual Immunotherapy Tablet in Allergic Asthma: A Systematic Review of Randomized Controlled Trials

BACKGROUND

House dust mite sublingual immunotherapy (HDM SLIT) effectively treats allergic rhinitis (AR). However, the evidence of HDM SLIT for allergic asthma remained limited.

OBJECTIVE

To systematically review the efficacy and safety of HDM SLIT tablets in patients with allergic asthma.

METHODS

We performed a systematic search through PubMed, Scopus, EMBASE, Web of Science, the Cochrane Center of Controlled Trials, and Google Scholar for randomized controlled trials (RCTs) that addressed the efficacy and safety of HDM SLIT tablets compared with placebo or no intervention in allergic asthma from their inception date until September 2021. The primary outcome was the reduction in inhaled corticosteroids (ICS) dose. Additional outcomes were asthma control, exacerbation, lung function, quality-of-life, and adverse events.

RESULTS

There were 7 RCTs, 5 studies in allergic asthma (4 in adults and 1 in children), and 2 in AR with or without asthma. The 6 standardized quality (SQ) HDM effectively reduced ICS dose in well- to partly controlled mild-to-moderate asthma in 1 RCT. Two RCTs evaluated the efficacy of 6 SQ and 12 SQ HDM in reducing asthma exacerbation in partly controlled moderate-to-severe asthma, and their results were inconsistent. One study in children with mild-to-moderate asthma found no benefit of HDM SLIT. Two RCTs in AR with or without mild-to-moderate asthma showed improvement of asthma symptoms. Adverse events were primarily local, and anaphylaxis treated with epinephrine was reported in 3 patients.

CONCLUSIONS

The HDM SLIT tablets tend to effectively reduce ICS use in adults and adolescents with well- to partly controlled mild-to-moderate allergic asthma with a favorable safety profile.

Allergen immunotherapy for pediatric asthma: current evidence and knowledge gaps

PURPOSE OF REVIEW

The introduction of high-quality and standardized extracts for immunotherapy has renewed the interest in the treatment of pediatric allergic asthma that represents a high-prevalence disease.

RECENT FINDINGS

In addition to clinical trials, several systematic reviews and metaanalyses were published, confirming overall the clinical efficacy of allergen immunotherapy in pediatric asthma. In addition, new data on the preventive effect of the treatment on asthma onset were published. Despite this, many intriguing questions emerged, in parallel to the development of knowledge.

SUMMARY

Allergen immunotherapy is overall effective for the treatment of asthma in children, but a class-effect should not be claimed, rather the efficacy of each single product. According to the recent findings, the challenge for the future research will be to clarify: when to start immunotherapy in children, which are (if they exist) the predictive biomarkers for efficacy in the single individual, the magnitude of the preventive effect and the optimal duration of the treatment.

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

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

2020 Focused Updates to the Asthma Management Guidelines: A Report from the National Asthma Education and Prevention Program Coordinating Committee Expert Panel Working Group

The 2020 Focused Updates to the Asthma Management Guidelines: A Report from the National Asthma Education and Prevention Program Coordinating Committee Expert Panel Working Group was coordinated and supported by the National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health. It is designed to improve patient care and support informed decision making about asthma management in the clinical setting. This update addresses six priority topic areas as determined by the state of the science at the time of a needs assessment, and input from multiple stakeholders:A rigorous process was undertaken to develop these evidence-based guidelines. The Agency for Healthcare Research and Quality's (AHRQ) Evidence-Based Practice Centers conducted systematic reviews on these topics, which were used by the Expert Panel Working Group as a basis for developing recommendations and guidance. The Expert Panel used GRADE (Grading of Recommendations, Assessment, Development and Evaluation), an internationally accepted framework, in consultation with an experienced methodology team for determining the certainty of evidence and the direction and strength of recommendations based on the evidence. Practical implementation guidance for each recommendation incorporates findings from NHLBI-led patient, caregiver, and clinician focus groups. To assist clincians in implementing these recommendations into patient care, the new recommendations have been integrated into the existing Expert Panel Report-3 (EPR-3) asthma management step diagram format.

Use of Sublingual Immunotherapy for Aeroallergens in Children with Asthma

Asthma is a heterogeneous disease that in children is often allergen-driven with a type 2 inflammation. Sublingual immunotherapy represents an important progress in the use of personalized medicine in children with allergic asthma. It is a viable option for house dust mite-driven asthma and in subjects with the asthma associated with allergic rhinitis. The use and indications for isolated asthma caused by other allergens are still controversial owing to heterogeneity of commercially available products and methodological limitations of studies in children. Nevertheless, most studies and meta-analyses found the efficacy of sublingual immunotherapy. Sublingual immunotherapy is safe but cannot be recommended in children with uncontrolled asthma.

Sublingual immunotherapy for asthma

BACKGROUND

Asthma is a common long-term respiratory disease affecting approximately 300 million people worldwide. Approximately half of people with asthma have an important allergic component to their disease, which may provide an opportunity for targeted treatment. Sublingual immunotherapy (SLIT) aims to reduce asthma symptoms by delivering increasing doses of an allergen (e.g. house dust mite, pollen extract) under the tongue to induce immune tolerance. Fifty-two studies were identified and synthesised in the original Cochrane Review in 2015, but questions remained about the safety and efficacy of sublingual immunotherapy for people with asthma.

OBJECTIVES

To assess the efficacy and safety of sublingual immunotherapy compared with placebo or standard care for adults and children with asthma.

SEARCH METHODS

The original searches for trials from the Cochrane Airways Group Specialised Register (CAGR), ClinicalTrials.gov, WHO ICTRP, and reference lists of all primary studies and review articles found trials up to 25 March 2015. The most recent search for trials for the current update was conducted on 29 October 2019.

SELECTION CRITERIA

We included parallel randomised controlled trials, irrespective of blinding or duration, that evaluated sublingual immunotherapy versus placebo or as an add-on to standard asthma management. We included both adults and children with asthma of any severity and with any allergen-sensitisation pattern. We included studies that recruited participants with asthma, rhinitis, or both, providing at least 80% of trial participants had a diagnosis of asthma. We selected outcomes to reflect recommended outcomes for asthma clinical trials and those most important to people with asthma. Primary outcomes were asthma exacerbations requiring a visit to the emergency department (ED) or admission to hospital, validated measures of quality of life, and all-cause serious adverse events (SAEs). Secondary outcomes were asthma symptom scores, exacerbations requiring systemic corticosteroids, response to provocation tests, and dose of inhaled corticosteroids (ICS).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results for included trials, extracted numerical data, and assessed risk of bias, all of which were cross-checked for accuracy. Any disagreements were resolved by discussion. We analysed dichotomous data as odds ratios (ORs) or risk differences (RDs) using study participants as the unit of analysis; we analysed continuous data as mean differences (MDs) or standardised mean differences (SMDs) using random-effects models. We considered the strength of evidence for all primary and secondary outcomes using the GRADE approach.

MAIN RESULTS

Sixty-six studies met the inclusion criteria for this update, including 52 studies from the original review. Most studies were double-blind and placebo-controlled, varied in duration from one day to three years, and recruited participants with mild or intermittent asthma, often with comorbid allergic rhinitis. Twenty-three studies recruited adults and teenagers; 31 recruited only children; three recruited both; and nine did not specify. The pattern of reporting and results remained largely unchanged from the original review despite 14 further studies and a 50% increase in participants studied (5077 to 7944). Reporting of primary efficacy outcomes to measure the impact of SLIT on asthma exacerbations and quality of life was infrequent, and selective reporting may have had a serious effect on the completeness of the evidence; 16 studies did not contribute any data, and a further six studies could only be included in a post hoc analysis of all adverse events. Allocation procedures were generally not well described; about a quarter of the studies were at high risk of performance or detection bias (or both); and participant attrition was high or unknown in around half of the studies. The primary outcome in most studies did not align with those of interest to the review (mostly asthma or rhinitis symptoms), and only two small studies reported our primary outcome of exacerbations requiring an ED or hospital visit; the pooled estimate from these studies suggests SLIT may reduce exacerbations compared with placebo or usual care, but the evidence is very uncertain (OR 0.35, 95% confidence interval (CI) 0.10 to 1.20; n = 108; very low-certainty evidence). Nine studies reporting quality of life could not be combined in a meta-analysis and, whilst the direction of effect mostly favoured SLIT, the effects were often uncertain and small. SLIT likely does not increase SAEs compared with placebo or usual care, and analysis by risk difference suggests no more than 1 in 100 people taking SLIT will have a serious adverse event (RD -0.0004, 95% CI -0.0072 to 0.0064; participants = 4810; studies = 29; moderate-certainty evidence). Regarding secondary outcomes, asthma symptom and medication scores were mostly measured with non-validated scales, which precluded meaningful meta-analysis or interpretation, but there was a general trend of SLIT benefit over placebo. Changes in ICS use (MD -17.13 µg/d, 95% CI -61.19 to 26.93; low-certainty evidence), exacerbations requiring oral steroids (studies = 2; no events), and bronchial provocation (SMD 0.99, 95% CI 0.17 to 1.82; low-certainty evidence) were not often reported. Results were imprecise and included the possibility of important benefit or little effect and, in some cases, potential harm from SLIT. More people taking SLIT had adverse events of any kind compared with control (OR 1.99, 95% CI 1.49 to 2.67; high-certainty evidence; participants = 4251; studies = 27), but events were usually reported to be transient and mild. Lack of data prevented most of the planned subgroup and sensitivity analyses.

AUTHORS' CONCLUSIONS

Despite continued study in the field, the evidence for important outcomes such as exacerbations and quality of life remains too limited to draw clinically useful conclusions about the efficacy of SLIT for people with asthma. Trials mostly recruited mixed populations with mild and intermittent asthma and/or rhinitis and focused on non-validated symptom and medication scores. The review findings suggest that SLIT may be a safe option for people with well-controlled mild-to-moderate asthma and rhinitis who are likely to be at low risk of serious harm, but the role of SLIT for people with uncontrolled asthma requires further evaluation.

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.

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.

EAACI Guidelines on Allergen Immunotherapy: House dust mite-driven allergic asthma

Allergen immunotherapy (AIT) has been in use for the treatment of allergic disease for more than 100 years. Asthma treatment relies mainly on corticosteroids and other controllers recommended to achieve and maintain asthma control, prevent exacerbations, and improve quality of life. AIT is underused in asthma, both in children and in adults. Notably, patients with allergic asthma not adequately controlled on pharmacotherapy (including biologics) represent an unmet health need. The European Academy of Allergy and Clinical Immunology has developed a clinical practice guideline providing evidence-based recommendations for the use of house dust mites (HDM) AIT as add-on treatment for HDM-driven allergic asthma. This guideline was developed by a multi-disciplinary working group using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. HDM AIT was separately evaluated by route of administration and children and adults: subcutaneous (SCIT) and sublingual AIT (SLIT), drops, and tablets. Recommendations were formulated for each. The important prerequisites for successful treatment with HDM AIT are (a) selection of patients most likely to respond to AIT and (b) use of allergen extracts and desensitization protocols of proven efficacy. To date, only AIT with HDM SLIT-tablet has demonstrated a robust effect in adults for critical end points (exacerbations, asthma control, and safety). Thus, it is recommended as an add-on to regular asthma therapy for adults with controlled or partially controlled HDM-driven allergic asthma (conditional recommendation, moderate-quality evidence). HDM SCIT is recommended for adults and children, and SLIT drops are recommended for children with controlled HDM-driven allergic asthma as the add-on to regular asthma therapy to decrease symptoms and medication needs (conditional recommendation, low-quality evidence).

Sublingual allergen immunotherapy for respiratory allergy: a systematic review

The objective of the systematic review is to provide complete and updated information on efficacy and safety of sublingual immunotherapy (SLIT) formulations for the treatment of allergic respiratory diseases (ARDs). The literature search was conducted on PubMed database, involving double-blind, randomized clinical trials published between January 1992 and 2018, written in English, and performed in humans. The number of articles finally selected for review was 112. Data from the majority of properly controlled clinical trials demonstrate that SLIT is effective not only with short-term use (first year) but also with long-term use (up to the third year of active therapy), for treating ARDs in children and adults. Both continuous and discontinuous schemes of administration showed significant reductions in symptom and medication scores. Moreover, a SLIT-induced disease-modifying effect has been documented mainly with grass pollen extracts, since improvement is maintained during at least 2 years of follow-up after a 3-year treatment period. Additionally, allergen immunotherapy should also be considered a preventive strategy, especially for decreasing bronchial asthma incidence in children and adolescents with allergic rhinitis treated with SLIT. This therapy is also safe, producing only a few mainly local and mild-to-moderate adverse events, and usually self-limited in time. The registration and authorization of allergen SLIT preparations (grasses and house-dust mite tablets) as drugs by regulatory agencies, such as the United States Food and Drug Administration (FDA) and the European Medicines Agency (EMA), has represented a landmark in allergy immunotherapy research. Further long-term studies, specially designed with allergens other than grass pollen or house-dust mites, not only in allergic rhinoconjunctivitis but also on asthmatic subjects, as well as studies comparing different administration schedules and/or routes, are required in order to continue the progress in the modern development of this particularly promising therapy.

Role of sublingual immunotherapy in the treatment of asthma: An updated systematic review

BACKGROUND

The purpose of the systematic review is to evaluate the efficacy and safety of sublingual immunotherapy (SLIT) for the treatment of allergic asthma.

METHODS

PubMed, Embase, and CENTRAL databases were searched, updating an earlier review (January 1, 2005 through May 8, 2017). Randomized, controlled studies (RCTs) were included, which reported one of the prespecified outcomes: asthma symptoms measured by control composite scores; quality of life; medication use; pulmonary physiology; and health-care utilization. For safety outcomes, RCTs and observational studies were included. Two independent reviewers extracted data, assessed risk of bias, and graded strength of evidence (SOE) for each outcome.

RESULTS

Fourteen RCTs (n = 2585) assessed the efficacy of SLIT for asthma. The RCTs utilized house dust mite (HDM), birch, or grass allergen. SLIT improved asthma symptoms (high SOE), decreased use of long-term control medication, and improved forced expiratory volume in 1 second (FEV₁ ) (moderate SOE). SLIT may decrease quick-relief medication use, and improve disease-specific quality of life (low SOE). For safety, 20 RCTs and 10 observational studies (n = 3621) were identified. Local (risk differences ranged from -0.03 to +0.765) and systemic allergic reactions (risk differences ranged from -0.03 to +0.06) were a common occurrence in SLIT and control groups. Life-threatening reactions were uncommon, with 3 cases of anaphylaxis and no deaths reported.

CONCLUSION

There is moderate-to-high strength evidence that SLIT improves allergic asthma symptoms, reduces long-term control medication use, and improves FEV₁ based on studies of HDM, birch, and grass. SLIT rarely is associated with life-threatening adverse events.

Positive and negative AIT trials: What makes the difference?

Background

Allergen immunotherapy has proven to be efficacious in allergic rhinitis and asthma. However, results from randomised clinical trials may vary substantially. Clinical trials may unexpectedly fail. The purpose of this review is to discuss the possible factors that may contribute to a successful or unsuccessful study.

Methods

Descriptive review exploring the possible causes of negative outcomes in allergen immunotherapy trials.

Results

A series of factors may lead to negative results. Among of these are underpowering of the study, low allergen content in tested extracts, insufficient allergen exposure during monitoring and recruitment of inappropriate patients. In addition, the choice of the primary endpoint may be critical.

Discussion

A clinical trial aims to evaluate the efficacy of an agent. However, studies with potential effective compounds may fail because of methodical issues. Sometimes, they are the cause of discrepancies between successful phase II and unsuccessful phase III trials. To understand more about failure of studies, investigators and editors should be encouraged to publish negative trials.

Allergen-Specific Immunotherapy in the Treatment of Pediatric Asthma: A Systematic Review

CONTEXT

Treatment options for allergic asthma include allergen avoidance, pharmacotherapy, and allergen immunotherapy.

OBJECTIVES

Summarize and update current evidence for the efficacy and safety of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) in pediatric allergic asthma.

DATA SOURCES

PubMed, Embase, Cochrane Central Register of Controlled Trials (January 1, 2005, through May 8, 2017), ClinicalTrials.gov, and the US Food and Drug Administration Adverse Event Reporting System. We reevaluated trials from our 2013 systematic review.

STUDY SELECTION

We included studies with children ≤18 years of age in which researchers reported on prespecified outcomes and had an intervention arm receiving aeroallergen SCIT or SLIT. Only randomized controlled trials (RCTs) were included for efficacy. RCTs and non-RCTs were included for safety outcomes.

DATA EXTRACTION

Two reviewers extracted data. We included 40 studies (17 SCIT trials, 11 SLIT trials, 8 non-RCTs for SCIT safety, and 4 non-RCTs for SLIT safety).

RESULTS

We found moderate-strength evidence that SCIT reduces long-term asthma medication use. We found low-strength evidence that SCIT improves asthma-related quality of life and forced expiratory volume in 1 second. There was also low-strength evidence that SLIT improves medication use and forced expiratory volume in 1 second. There was insufficient evidence on asthma symptoms and health care use.

LIMITATIONS

There were no trials in which researchers evaluated asthma symptoms using a validated tool. Study characteristics and outcomes were reported heterogeneously.

CONCLUSIONS

In children with allergic asthma, SCIT may reduce long-term asthma medication use. Local and systemic allergic reactions are common, but anaphylaxis is reported rarely.

House Dust Mite Sublingual Immunotherapy for Pediatric Patients With Allergic Asthma

OBJECTIVE

To review the published literature evaluating administration of house dust mite (HDM) sublingual immunotherapy (SLIT) in pediatric patients with allergic asthma.

DATA SOURCES

PubMed database search (1966 to November 2017) using the search terms allergy, allergic rhinitis, asthma, allergic asthma, house dust mite, allergen immunotherapy, subcutaneous immunotherapy, sublingual immunotherapy, MK-8237, children, and pediatric. Package labeling and references from identified articles were also reviewed.

STUDY SELECTION AND DATA EXTRACTION

Studies published in English evaluating the efficacy of HDM SLIT in children <18 years of age were included.

DATA SYNTHESIS

Patients with allergic asthma who fail to improve with pharmacotherapy may require disease-modifying, HDM-specific immunotherapy. Acceptance of subcutaneous immunotherapy (SCIT) in the pediatric population is limited by the need for weekly injections and the risk of systemic adverse effects. Trials in pediatric patients with allergic rhinitis and asthma monosensitized to HDM demonstrated mixed results, likely because of variability in methodologies. SLIT reduced asthma symptoms in 8 placebo-controlled studies; however, asthma medication use was reduced in just 4 trials. Compared with pharmacotherapy alone, SLIT and SCIT decreased asthma symptom scores similarly for up to 3 years. Sequential SCIT/SLIT decreased both asthma symptoms and medication scores and was more effective than SLIT alone.

CONCLUSIONS

Sublingual HDM immunotherapy reduces symptom scores in pediatric patients with allergic asthma but may be slower in onset and less effective than SCIT in reducing asthma medication use.

Applicability of evidence from previous systematic reviews on immunotherapy in current practice of childhood asthma treatment: a GRADE (Grading of Recommendations Assessment, Development and Evaluation) systematic review

OBJECTIVE

Because most children with asthma now use inhaled corticosteroids (ICS), the added benefit of immunotherapy in asthmatic children needs to be examined. We re-assessed the effectiveness of subcutaneous (SCIT) and sublingual immunotherapy (SLIT) in childhood asthma treatment focusing on studies with patient-relevant outcome measures and children using ICS.

METHODS

We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to systematically search and appraise the evidence using predefined critical patient-relevant outcomes (asthma symptoms, asthma control and exacerbations). We searched to retrieve systematic reviews and randomised controlled trials on immunotherapy for asthma in children (1960-2017). We assessed the quality of the body of evidence with GRADE criteria.

RESULTS

The quality of the evidence for SCIT was very low due to a large risk of bias and indirectness (dated studies in children not using ICS). No effect of SCIT was found for asthma symptoms; no studies reported on asthma control. For asthma exacerbations, studies favoured SCIT. We have little confidence in this effect estimate, due to the very low quality of evidence. For SLIT, quality of the evidence was very low due to a large risk of bias, indirectness and imprecision. The outcome 'asthma symptoms' could not be calculated due to lack of standardisation and large clinical heterogeneity. Other predefined outcomes were not reported.

CONCLUSION

The beneficial effects of immunotherapy in childhood asthma found in earlier reviews are no longer considered applicable, because of indirectness (studies performed in children not being treated according to current asthma guidelines with ICS). There was absence of evidence to properly determine the effectiveness or lack thereof of immunotherapy in asthma treatment in children with ICS.

Allergen immunotherapy for allergic asthma: A systematic review and meta-analysis

BACKGROUND

To inform the development of the European Academy of Allergy and Clinical Immunology's (EAACI) Guidelines on Allergen Immunotherapy (AIT) for allergic asthma, we assessed the evidence on the effectiveness, cost-effectiveness and safety of AIT.

METHODS

We performed a systematic review, which involved searching nine databases. Studies were screened against predefined eligibility criteria and critically appraised using established instruments. Data were synthesized using random-effects meta-analyses.

RESULTS

98 studies satisfied the inclusion criteria. Short-term symptom scores were reduced with a standardized mean difference (SMD) of -1.11 (95% CI -1.66, -0.56). This was robust to a prespecified sensitivity analyses, but there was evidence suggestive of publication bias. Short-term medication scores were reduced SMD -1.21 (95% CI -1.87, -0.54), again with evidence of potential publication bias. There was no reduction in short-term combined medication and symptom scores SMD 0.17 (95% CI -0.23, 0.58), but one study showed a beneficial long-term effect. For secondary outcomes, subcutaneous immunotherapy (SCIT) improved quality of life and decreased allergen-specific airway hyperreactivity (AHR), but this was not the case for sublingual immunotherapy (SLIT). There were no consistent effects on asthma control, exacerbations, lung function, and nonspecific AHR. AIT resulted in a modest increased risk of adverse events (AEs). Although relatively uncommon, systemic AEs were more frequent with SCIT; however no fatalities were reported. The limited evidence on cost-effectiveness was mainly available for sublingual immunotherapy (SLIT) and this suggested that SLIT is likely to be cost-effective.

CONCLUSIONS

AIT can achieve substantial reductions in short-term symptom and medication scores in allergic asthma. It was however associated with a modest increased risk of systemic and local AEs. More data are needed in relation to secondary outcomes, longer-term effectiveness and cost-effectiveness.

Sublingual immunotherapy (SLIT) for house dust mites does not prevent new allergen sensitization and bronchial hyper-responsiveness in allergic rhinitis children

Introduction

The aim of this study is to identify the effects of sublingual immunotherapy (SLIT) on immunologic parameters and bronchial-hyper-responsiveness in children with allergic rhinitis to house-dust mite (HDM), through long-term follow-up cohort.

Methods

Among the Allergic Rhinitis Cohort Study for Kids, pediatric patients who visited the hospital for rhinitis symptoms and proven allergy to HDM through skin prick test were studied. In this cohort, 37 patients received SLIT more than 3-years (SLIT group), and 184 patients received only pharmacologic therapy (non-SLIT group) were included in this study. The results of skin prick test, eosinophil percent and count, total immunoglobulin E (IgE), and bronchial provocation test at initial and 3-year followed-up were compared in the two groups.

Results

After 3 year follow-up, only the serum eosinophil percent decreased more significantly in SLIT group than that in the non-SLIT group. New-sensitization rate other than HDM between SLIT and non-SLIT group did not show any significant differences. The distribution of sensitized allergen other than HDM showed increasing tendency after 3 years in both groups. Older age and a small number of sensitized allergen affected the improvement of bronchial hyper-responsiveness regardless of SLIT.

Conclusion

HDM SLIT in allergic rhinitis children for 3 years in Korea does not affect prevention of new sensitization and poly-sensitization rate increment, and improvement of bronchial hyper-responsiveness.

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.

Critical appraisal of the clinical utility of sublingual immunotherapy in allergy

Since it was introduced by Noon in 1911, allergen-specific immunotherapy or desensitization has been widely prescribed in the management of allergic diseases. Aimed at the etiology, it represents the only effective treatment for allergy. The basic mechanisms of immunotherapy are becoming better understood and allow us to improve this technique in the future. The sublingual immunotherapy as an alternative to subcutaneous route has been widely studied. Several clinical trials confirmed that sublingual immunotherapy is efficient in reducing allergic respiratory symptoms. The sublingual immunotherapy reduces the risk of developing serious side effects due to desensitization. We performed a literature review in order to remind the mechanisms of action and to demonstrate efficacy and tolerability of the sublingual immunotherapy in the treatment of allergic rhinoconjunctivitis and asthma and its impact on the quality of life.

Therapeutic interventions in severe asthma

The present paper addresses severe asthma which is limited to 5-10% of the overall population of asthmatics. However, it accounts for 50% or more of socials costs of the disease, as it is responsible for hospitalizations and Emergency Department accesses as well as expensive treatments. The recent identification of different endotypes of asthma, based on the inflammatory pattern, has led to the development of tailored treatments that target different inflammatory mediators. These are major achievements in the perspective of Precision Medicine: a leading approach to the modern treatment strategy. Omalizumab, an anti-IgE antibody, has been the only biologic treatment available on the market for severe asthma during the last decade. It prevents the linkage of the IgE and the receptors, thereby inhibiting mast cell degranulation. In clinical practice omalizumab significantly reduced the asthma exacerbations as well as the concomitant use of oral glucocorticoids. In the "Th2-high asthma" phenotype, the hallmarks are increased levels of eosinophils and other markers (such as periostin). Because anti-IL-5 in this condition plays a crucial role in driving eosinophil inflammation, this cytokine or its receptors on the eosinophil surface has been studied as a potential target for therapy. Two different anti-IL-5 humanized monoclonal antibodies, mepolizumab and reslizumab, have been proven effective in this phenotype of asthma (recently they both came on the market in the United States), as well as an anti-IL-5 receptor alpha (IL5Rα), benralizumab. Other monoclonal antibodies, targeting different cytokines (IL-13, IL-4, IL-17 and TSLP) are still under evaluation, though the preliminary results are encouraging. Finally, AIT, Allergen Immunotherapy, a prototype of Precision Medicine, is considered, also in light of the recent evidences of Sublingual Immunotherapy (SLIT) tablet efficacy and safety in mite allergic asthma patients. Given the high costs of these therapies, however, there is an urgent need to identify biomarkers that can predict the clinical responders.

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.

Allergen specific sublingual immunotherapy in children with asthma and allergic rhinitis

BACKGROUND

The incidence of asthma and allergic rhinitis (AR) is significantly increased, especially in younger children. Current treatment for children with asthma and allergic rhinitis include allergen avoidance, standard pharmacotherapy, and immunotherapy. Since standard pharmacotherapy is prescribed for symptoms, immunotherapy at present plays an important role in the treatment of allergic diseases. This article presents insights into the up-to-date understanding of immunotherapy in the treatment of children with allergic rhinitis and asthma.

DATA SOURCES

PubMed articles published from 1990 to 2014 were reviewed using the MeSH terms "asthma", "allergic rhinitis", "children", and "immune therapy". Additional articles were identified by hand searching of the references in the initial search.

RESULTS

Numerous studies have shown that sublingual application of allergen specific immunotherapy (SLIT) is an adequate, safe and efficient substitution to subcutaneous route of allergens administration (SCIT) in the treatment of IgE-mediated respiratory tract allergies in children. According to the literature, better clinical efficacy is connected with the duration of treatment and mono sensitized patients.

CONCLUSIONS

At least 3 years of treatment and stable asthma before the immunotherapy are positive predictors of good clinical efficacy and tolerability of SLIT. SLIT reduces the symptoms of allergic diseases and the use of medicaments, and improves the quality of life of children with the diseases.

Grass pollen sublingual immunotherapy and paediatric allergic rhinitis: A patient-oriented decision

Guidelines and systematic review report that allergen immunotherapy (AIT) is, in general, effective in the treatment of allergic rhinitis. However, experts suggest not generalising the results of different clinical studies: for example, it would not be advisable to translate the results found in an adult population to a paediatric population or the results on the efficacy of AIT against a specific allergen to the AIT against a different allergen. Moreover, according to Evidence Based Medicine (EBM), clinical decisions are individualised and should derive from the "integration of best research evidence with clinical expertise and patient values". Taking into account the high specificity of the AIT and EBM principles, we tried to answer the question on how advisable it is to prescribe the AIT for the management of grass allergic rhinitis in children. To do this, we revised the scientific literature in order to solve a specific case scenario.

House dust mite sublingual immunotherapy is safe in patients with mild-to-moderate, persistent asthma: a clinical trial

BACKGROUND

The safety of allergen immunotherapy (AIT) in asthma has not always been sufficiently documented; accordingly, fear of asthma exacerbations has made physicians somewhat reluctant to prescribe AIT in this context. In a double-blind, placebo-controlled, randomized clinical trial, house dust mite (HDM) sublingual AIT was found to be efficacious in moderate, persistent asthma. The trial's safety results are now reported in detail.

METHODS

Asthmatic adults were randomized 2 : 1 to twelve months of daily treatment with a sublingual solution of Dermatophagoides pteronyssinus and Dermatophagoides farinae extracts or a placebo. Adverse events (AEs) at least possibly related to the investigational product were classified by the investigators as adverse drug reactions (ADRs).

RESULTS

Overall, the patients in the safety analysis set (n = 484; active treatment: n = 322; placebo: n = 162) had mostly well-controlled, persistent asthma [mild in 290 patients (59.9%), moderate in 183 (37.8%) and severe in 11 (2.3%)]. No treatment-related serious AEs were reported. A total of 87.0% and 75.9% of the patients in the active and placebo groups, respectively, experienced at least one AE (mostly mild), and 78.9% and 48.1% experienced an ADR (mostly mild or moderate oral reactions). The incidence of asthma exacerbations (symptoms requiring a short course of oral corticosteroids) during the study was similar in the active treatment group (3.7%) and the placebo group (4.3%). There were no significant intergroup differences or intragroup changes over time in respiratory AEs, lung function or asthma-related quality of life.

CONCLUSIONS

HDM sublingual AIT was safe and well tolerated in adult patients with mild-to-moderate, persistent asthma (ClinicalTrials.gov: NCT00660452).

The effects of house dust mite sublingual immunotherapy in patients with allergic rhinitis according to duration

BACKGROUND

The safety and efficacy of sublingual immunotherapy (SLIT) have been demonstrated in the recent 2 decades. However, the data is still mixed regarding the efficacy of house dust mite (HDM) SLIT. The objective of this work was to evaluate the different clinical efficacy SLIT in patients with allergic rhinitis (AR) according to different durations of treatment.

METHODS

A total of 500 subjects with HDM-induced AR were randomized to receive SLIT with Dermatophagoides farinae (Der.f) drops or pharmacotherapy with oral antihistamines. Patients in the SLIT group were further divided into SLIT1, SLIT2, and SLIT3 subgroups. After SLIT completion, a yearly follow-up visit was given to patients in the SLIT1 and SLIT2 subgroups. The total nasal symptom score (TNSS), the proportion of medication withdrawal, the visual analogue scale (VAS) score, and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scores were assessed at each monthly visit.

RESULTS

Comparing with the baseline value, TNSS, VAS, and RQLQ were significantly improved in 3 SLIT subgroups after treatment (p < 0.05). In addition, patients in SLIT3 subgroup achieved the highest proportion of medication withdrawal compared to the SLIT1 and SLIT2 subgroups (p < 0.05). After 1-year follow-up, no significant differences were observed in TNSS, VAS scores, and the proportion of medication withdrawal of SLIT1 and SLIT2 subgroups (p > 0.05) with respect to the completion value. No severe systemic adverse events (AEs) were reported.

CONCLUSION

The randomized study suggested that 3-year courses of SLIT in patients with AR was more efficacious than 1-year or 2-year courses. Furthermore, patients achieved 1-year long-term clinical benefits from HDM SLIT.

Sublingual immunotherapy for asthma

BACKGROUND

Asthma is a common long-term respiratory disease affecting approximately 300 million people worldwide. Approximately half of people with asthma have an important allergic component to their disease, which may provide an opportunity for targeted treatment. Sublingual immunotherapy (SLIT) aims to reduce asthma symptoms by delivering increasing doses of an allergen (e.g. house dust mite, pollen extract) under the tongue to induce immune tolerance. However, it is not clear whether the sublingual delivery route is safe and effective in asthma.

OBJECTIVES

To assess the efficacy and safety of sublingual immunotherapy compared with placebo or standard care for adults and children with asthma.

SEARCH METHODS

We identified trials from the Cochrane Airways Group Specialised Register (CAGR), ClinicalTrials.gov (www.ClinicalTrials.gov), the World Health Organization (WHO) trials portal (www.who.int/ictrp/en/) and reference lists of all primary studies and review articles. The search is up to date as of 25 March 2015.

SELECTION CRITERIA

We included parallel randomised controlled trials (RCTs), irrespective of blinding or duration, that evaluated sublingual immunotherapy versus placebo or as an add-on to standard asthma management. We included both adults and children with asthma of any severity and with any allergen-sensitisation pattern. We included studies that recruited participants with asthma, rhinitis, or both, providing at least 80% of trial participants had a diagnosis of asthma.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results for included trials, extracted numerical data and assessed risk of bias, all of which were cross-checked for accuracy. We resolved disagreements by discussion.We analysed dichotomous data as odds ratios (ORs) or risk differences (RDs) using study participants as the unit of analysis; we analysed continuous data as mean differences (MDs) or standardised mean differences (SMDs) using random-effects models. We rated all outcomes using GRADE (Grades of Recommendation, Assessment, Development and Evaluation) and presented results in the 'Summary of findings' table.

MAIN RESULTS

Fifty-two studies met our inclusion criteria, randomly assigning 5077 participants to comparisons of interest. Most studies were double-blind and placebo-controlled, but studies varied in duration from one day to three years. Most participants had mild or intermittent asthma, often with co-morbid allergic rhinitis. Eighteen studies recruited only adults, 25 recruited only children and several recruited both or did not specify (n = 9).With the exception of adverse events, reporting of outcomes of interest to this review was infrequent, and selective reporting may have had a serious effect on the completeness of the evidence. Allocation procedures generally were not well described, about a quarter of the studies were at high risk of bias for performance or detection bias or both and participant attrition was high or unknown in around half of the studies.One short study reported exacerbations requiring a hospital visit and observed no adverse events. Five studies reported quality of life, but the data were not suitable for meta-analysis. Serious adverse events were infrequent, and analysis using risk differences suggests that no more than 1 in 100 are likely to suffer a serious adverse event as a result of treatment with SLIT (RD 0.0012, 95% confidence interval (CI) -0.0077 to 0.0102; participants = 2560; studies = 22; moderate-quality evidence).Within secondary outcomes, wide but varied reporting of largely unvalidated asthma symptom and medication scores precluded meaningful meta-analysis; a general trend suggested SLIT benefit over placebo, but variation in scales meant that results were difficult to interpret.Changes in inhaled corticosteroid use in micrograms per day (MD 35.10 mcg/d, 95% CI -50.21 to 120.42; low-quality evidence), exacerbations requiring oral steroids (studies = 2; no events) and bronchial provocation (SMD 0.69, 95% CI -0.04 to 1.43; very low-quality evidence) were not often reported. This led to many imprecise estimates with wide confidence intervals that included the possibility of both benefit and harm from SLIT.More people taking SLIT had adverse events of any kind compared with control (OR 1.70, 95% CI 1.21 to 2.38; low-quality evidence; participants = 1755; studies = 19), but events were usually reported to be transient and mild.Lack of data prevented most of the planned subgroup and sensitivity analyses.

AUTHORS' CONCLUSIONS

Lack of data for important outcomes such as exacerbations and quality of life and use of different unvalidated symptom and medication scores have limited our ability to draw a clinically useful conclusion. Further research using validated scales and important outcomes for patients and decision makers is needed so that SLIT can be properly assessed as clinical treatment for asthma. Very few serious adverse events have been reported, but most studies have included patients with intermittent or mild asthma, so we cannot comment on the safety of SLIT for those with moderate or severe asthma. SLIT is associated with increased risk of all adverse events.

Allergen immunotherapy in asthma; what is new?

The use and role of allergen immunotherapy (AIT) in asthma is still a matter of debate, and no definite recommendation about this is made in guidelines, both for the subcutaneous and sublingual routes. This is essentially due to the fact that most controlled randomised trials were not specifically designed for asthma, and that objective measures of pulmonary function were only occasionally considered. Nonetheless, in many trials, favourable results in asthma (symptoms, medication usage, bronchial reactivity) were consistently reported. There are also several meta analyses in favour of AIT, although their validity is limited by a relevant methodological heterogeneity. In addition to the crude clinical effect, a disease modifying action of AIT (prevention of asthma onset and long-lasting effects) have been reported. The safety is an important aspect to consider in asthma. Fatalities were rare: in Europe no fatality was reported in the last three decades, as in the United States in the last 4 years. Based on previous surveys, and common sense, uncontrolled asthma is still recognized as the most important risk factor for severe adverse events. On the contrary, there is no evidence that AIT can worsen or induce asthma. According to the available evidence, AIT can be safely used as add-on treatment when asthma is associated with rhinitis (a frequent condition), provided that asthma is adequately controlled by pharmacotherapy. AIT cannot be recommended or suggested as single therapy. When asthma is the unique manifestation of respiratory allergy, its use should be evaluated case by case.

Long-term adherence to sublingual therapy: literature review and suggestions for management strategies based on patients' needs and preferences

Sublingual immunotherapy (SLIT) is an at-home, self-administered, long-term therapy. As with other chronic diseases, patient adherence is a prerequisite for the success of SLIT. Its ease of intake and convenience should ensure adequate patient compliance; however, a recent post-marketing manufacturers' survey has shown a very high rate of discontinuation. The available literature on patient adherence to SLIT is reviewed in the present article. Great differences exist between controlled studies, which show a satisfactory adherence rate, and long-term real-life studies, which show poor compliance with SLIT. Remarkable divergence in the weight placed on different reasons for SLIT discontinuation is reported in the various studies. The main reasons for withdrawal are analysed and discussed. Data from placebo-controlled studies demonstrate that adherence depends less on the patient's perception of the inefficacy of therapy or other causes than on the patient's motivation, that is the patient's decision to participate in the trial and to meet the researcher's expectations. The enrolment of patients who agree to enter a blind, placebo-controlled trial is conceptually similar to a concordance process. Concordance is a consultation process that aims to establish a therapeutic alliance between the physician and patient and to bring about agreement on a therapeutic programme. Concordance is based on the patient's beliefs and needs and implies actions that support the patient's adherence. Suggestions are given for a SLIT management strategy based on the concordance process and designed to integrate the patient's viewpoints into treatment-related decisions and to meet patients' preferences and their health-system-related needs.

Dosing of sublingual immunotherapy for allergic rhinitis: evidence-based review with recommendations

BACKGROUND

Since the mid 1980s, the clinical use of sublingual immunotherapy (SLIT) has dramatically increased. However, 1 of the primary barriers to providing SLIT is lack of a published dosing recommendations. The purpose of this work is to provide a range of effective SLIT dosing based upon a rigorous review of the existing evidence base. An appendix with SLIT dosing recommendations is also included.

METHODS

A comprehensive search of the past 25 years of the medical literature using PubMed was performed for specific antigens. Inclusion criteria for articles included: randomized, placebo-controlled studies of SLIT, studies with clinical allergic rhinitis outcomes, and dosing units available to determine the micrograms per month of major allergen administered. The extracted data was used to compile a range of effective SLIT dosing for individual antigens.

RESULTS

Seventy-five articles met the inclusion criteria, providing a range of effective dosing for some allergens. There was commonly a wide range in doses for particular antigens between the individual studies. For some antigens, there was significant overlap in dosage amount between studies showing efficacy and lack of efficacy. Clinical trials meeting inclusion criteria are not available for many allergens.

CONCLUSION

This study provided a comprehensive review of the published sublingual dosing ranges for specific antigens. The review provided a range of effective sublingual doses for some allergens, whereas for other allergens there was insufficient published data to determine specific doses. Recommendations for SLIT dosing were produced based on the data revealed in the review and expert opinion.

Sublingual Immunotherapy for Asthmatic Children Sensitized to House Dust Mite: A Meta-Analysis

The house dust mite is one of the most common allergens worldwide. There is good evidence that house dust mite subcutaneous immunotherapy is efficacious and has long-term benefit in children. However, the evidence of the benefit of house dust mite sublingual immunotherapy (SLIT) is less convincing. The purpose of this meta-analysis was to evaluate that efficacy and safety of dust mite SLIT in children with asthma. Medical Literature Analysis and Retrieval System Online, ISI Web of Knowledge, and Cochrane Central Register of Controlled Trials databases until February 2014 were searched. The primary outcome was mean change in asthma symptom score. Secondary outcomes included mean change in serum immunoglobulin G4 (sIgG4), specific Dermatophagoides pteronyssinus, immunoglobulin E (IgE) levels, and medication score. Safety was also assessed. We found that SLIT significantly decreased asthma symptom score (P = 0.007) and increased sIgG4 levels (P = 0.011) greater than control in children (<18 years of age) with asthma. There was no difference between SLIT and control groups in specific D pteronyssinus IgE levels (P = 0.076) and medication score (P = 0.408). The safety profile was similar between groups. Our study indicates that dust mite SLIT therapy was effective in reducing asthma symptoms and in increasing sIgG4 but did not significantly reduce medication scores or specific D pteronyssinus IgE levels. Our findings are not enough to support the use of dust mite SLIT in children with asthma.

Mite-Allergic Rhinitis: How to Evaluate Clinical Efficacy in Allergen-Specific Immunotherapy Trials?

House dust mite (HDM) allergen exposure is the most important cause of perennial allergic rhinitis and/or asthma. Although allergen-specific immunotherapy (AIT) with HDM is well established, published studies have been characterized by substantial heterogeneity in clinical endpoints. Standardization in measuring clinical efficacy is required. Moreover, when designing an AIT trial with HDM allergens, several considerations have to be taken into account. The history of HDM allergy is less clear cut than the typical history of pollen allergy. In addition, clinical features of HDM allergy may differ from those of pollen allergy. Moreover, although not easily measurable, fluctuation in allergen exposure may cause variation in symptom severity and determine the timing of assessment of clinical effects of HDM AIT. Key points 1. A combined symptom and medication score (CSMS) is recommended as standard for the primary endpoint in future house dust mite (HDM) allergen-specific immunotherapy trials. 2. The diagnosis of HDM allergy is based on a carefully taken history in combination with sensitization to HDM allergens. 3. Eye symptoms are less prominent in patients with HDM-induced allergic rhinitis. Nasal symptoms, but not eye symptoms, should be included in the CSMS and in symptom scores as well. 4. As methods to determine allergen exposure vary and the efficacy of environmental control is a matter of debate, a practical approach consists of restraining patients from implementing HDM-reducing measures, such as removing carpets and introducing anti-mite covers, after the start of the study. 5. Efficacy evaluation in the period with the highest exposure to mites is recommended.

A milestone in house dust-mite-allergen immunotherapy: the new sublingual tablet S-524101 (actair)

Subcutaneous allergen-specific immunotherapy has long been used in the treatment of allergic rhinitis and/or asthma and its efficacy has been confirmed. However, due to the discomfort of injections and the risk of severe adverse reactions, alternative routes of allergen administration have emerged. Delivery of allergens through the mucosal route had been proposed and investigated thoroughly, confirming the sublingual route to be the most efficacious. Later, the efficacy and safety of this route have been documented by numerous controlled trials both for house dust mite (HDM) and pollens. Recently, sublingual orodispersable grass pollen allergen tablets were in use followed by the newly developed HDM allergen tablets with satisfactory clinical results: Moreover, very recently 1 year of HDM tablet treatment was demonstrated to exert its clinical efficacy 1 year after discontinuation of tablet IT. The persistence of efficacy after only 1 year of treatment is a new and promising era. Currently, Sublingual Immunotherapy is the most easily administered and safe treatment option until more immunogenic, less allergenic and more efficient allergen extracts are developed.

Recommendations for appropriate sublingual immunotherapy clinical trials

Sublingual immunotherapy is currently considered a viable alternative to the subcutaneous route. The body of evidence of its efficacy is based on the results of 77 clinical trials and 7 meta-analyses, that have been published so far. Nonetheless, the experimental evidence is partially weak due to the large heterogeneity of studies, namely: doses, regimens, patient selection, duration of treatment, outcomes and reporting. In addition, it is virtually impossible to compare the potency of extracts produced by different manufacturers. Also, there is large variability in reporting and in the classification of adverse events, either systemic or local, so that only a rough estimate can be provided. Considering all these aspects, efforts are needed to harmonize the methodology, outcome measures and reporting of SLIT clinical trials, to achieve the ability of comparing the results of various studies. International societies and the World Allergy Organization have recently provided general recommendations on how to design and conduct trials which can provide more interpretable and homogeneous data.

House dust mite sublingual immunotherapy is safe and appears to be effective in moderate, persistent asthma

BACKGROUND

The efficacy and safety of sublingual immunotherapy in house dust mite-induced asthma have yet to be firmly established. We report the results of a double-blind, placebo-controlled, randomized clinical trial performed in mainland China.

METHODS

After a three-month baseline period, 484 asthmatic adults were randomized 2 : 1 to 12 months of daily treatment with either an aqueous, standardized, 300 index of reactivity mixture of Dermatophagoides pteronyssinus and Dermatophagoides farinae extracts or a placebo. The primary efficacy criterion was well-controlled asthma for at least 16 of the last 20 weeks of treatment.

RESULTS

In the active (n = 308) and placebo (n = 157) groups, well-controlled asthma was achieved by 85.4% and 81.5% of the patients, respectively (P = 0.244). A subsequent post hoc analysis by asthma severity revealed significant clinical benefits in actively treated subjects with moderate, persistent asthma at baseline [401-800 μg budesonide/day (n = 175)], with greater achievement of well-controlled asthma (80.5% and 66.1% for the active treatment and placebo groups, respectively; P = 0.021) and totally controlled asthma (54.0% and 33.9%, respectively, P = 0.008), a higher percentage of patients with an asthma control questionnaire score < 0.75 (56.6% and 40.0%, respectively; P = 0.039) and a greater mean reduction in inhaled corticosteroid use (218.5 μg and 126.2 μg, respectively; P = 0.004). The active vs placebo differences in disease control and corticosteroid use were not significant for mild, persistent asthma. No treatment-related serious adverse events were reported.

CONCLUSIONS

Sublingual mite allergen immunotherapy was well tolerated in adult asthmatics and effectively controlled disease in patients with moderate (but not mild) persistent asthma (ClinicalTrials.gov: NCT00660452).

An update on allergen immunotherapy and asthma

PURPOSE OF REVIEW

The aim is to review recent literature up to July 2013 concerning the effect of allergen-specific immunotherapy (AIT) on asthma. AIT, effective in combined allergic rhinitis and asthma, was previously described as a convenient approach able to improve clinical outcomes and reduce bronchial hyperresponsiveness. In addition, long-term and preventive effects on the onset of new sensitizations and progression from allergic rhinitis to asthma have been shown.

RECENT FINDINGS

Recent investigations, mainly based on observational or small open trials, confirmed previous findings, showing improvement in asthma control, symptoms and medication usage and steroid-sparing effects, sometimes inconsistent with changes in lung function. Some meta-analyses support the clinical benefit on adult and paediatric asthma. Only few trials, however, were specifically designed to explore asthma endpoints.

SUMMARY

Clinical studies primarily have focused on AIT, and research on asthma endpoints is scarce; however, the evidence of beneficial effect of AIT for the treatment of adults and children affected by allergic rhinitis with or without asthma suggests that this treatment can favourably affect asthma. In children, sublingual AIT has been more extensively investigated than injective. Confirmatory, adequately powered trials are needed to reinforce the evidence of efficacy for individual AIT products. The main drawback in using injective AIT for asthma is the risk of serious adverse reactions and uncontrolled asthma. The sublingual route is better tolerated and does not appear inferior. As standard controller pharmacotherapy seems unable to affect the natural course of asthma, the potentially disease-modifying effect of AIT represents an appealing perspective that requires further investigation.

Dropouts in sublingual allergen immunotherapy trials - a systematic review

Participant dropouts can reduce the power of allergen immunotherapy clinical trials. Evaluation of the dropout rate and reasons for dropout are important not only in the planning of clinical studies but are also relevant for adherence to immunotherapy in daily clinical practice. A systematic review was carried out in order to establish the overall dropout rate among published double-blind, placebo-controlled randomized clinical trials of sublingual immunotherapy for respiratory allergic diseases. Dropouts were analysed in regards to allergen, formulation, treatment schedule, participant age, study size, number of centres and type of allergic disease. Relative dropout rates in placebo and active groups as well as reasons for dropout were also assessed. A total of 81 studies, comprising 9998 patients, were included. Dropout rates in sublingual immunotherapy controlled studies do not appear to be a major problem with a composite dropout percentage of 14% (95% CI:11.9-16). Furthermore, they are not different for active compared to placebo-treated participants. This lends support to the positive clinical outcomes seen in meta-analyses of these trials.

Efficacy of sublingual immunotherapy for allergic asthma: retrospective meta-analysis of randomized, double-blind and placebo-controlled trials

BACKGROUND

Allergen-specific immunotherapy (SIT) is the only available curative choice with a disease-modifying effect against respiratory allergies. The efficacy of SIT via the sublingual route was demonstrated by a number of clinical trials. This meta-analysis was performed to investigate the clinical efficacy and safety of sublingual-specific immunotherapy (SLIT) for allergic asthma.

METHODS

PubMed, EMBASE and the Cochrane Central Register of Controlled Trials were searched for randomized, double-blind and placebo-controlled (DBPC) trials evaluating the efficacy and safety of SLIT on allergic asthma. Subgroup analyses were performed according to age, type of allergen and duration of SLIT treatment.

RESULTS

Sixteen randomized DBPC trials comprising 794 patients in total met the inclusion criteria. The results suggest that SLIT significantly reduces both symptom [standardized mean difference (SMD), -0.74; P=0.006] and medication scores (SMD, -0.78; P=0.02) compared with placebo. SLIT offers a better clinical response in mite sensitive asthmatics but without confirmed proof from subgroup analyses. Prolonged duration of treatment for more than 12 months brings no additive effects. Improvement in the skin prick test was also observed following immunotherapy. There was no consistent effect on forced expiratory volume in 1 s, serum levels of antigen-specific immunoglobulin G4 and immunoglobulin E in the treated group. The risk of adverse effects was relative risk 2.23 (P=0.01).

CONCLUSIONS

SLIT is safe and clinically effective in reducing symptoms and medication use for allergic asthma. Our subgroup analyses failed to identify a disproportionate benefit of SLIT in any specific group of asthmatics, but some possible trends did emerge.

Recombinant house dust mite allergens

House dust mites (HDM) are a globally important source of allergen responsible for the sensitization of more than 50% of allergic patients. Specific immunotherapy with HDM extracts is effective but allergen extracts cannot be fully standardized and severe side-effects can occur during the protracted course of treatment. The introduction of molecular biological techniques into allergy research allowed the indentification of more than 20 groups of HDM allergens. Recombinant HDM allergens can be produced in defined concentrations and consistent quality and allow the development of vaccines for HDM allergy with reduced allergenic activity and retained immunogenicity. The immunotherapy trials in pollen allergic patients with recombinant pollen allergens/hypoallergenic allergen derivatives have shown that this treatment is effective and indicated that recombinant HDM vaccines might improve immunotherapy of HDM allergic patients. Here we report the steps for the development of vaccines for HDM allergy. After selection of the most prevalent HDM species, the panel of allergens to be included into a therapeutic vaccine for HDM allergy needs to be determined. HDM allergens with high IgE-binding frequency and clinical relevance will be modified into hypoallergenic variants and evaluated for their allergenic activity and immunogenicity. Derivatives with reduced allergenic activity but with retained immunogenicity would be good candidates for a HDM vaccine for safe and efficient immunotherapy.

Allergen-specific immunotherapy in asthmatic children: from the basis to clinical applications

Atopic asthma in childhood with the tendency to persist into adult life is an important issue in pediatrics. Allergen-specific immunotherapy (SIT) is the only curative treatment option for these children, being directed to the causes of the disease. The Th2 phenotype is a predominant immunological pattern in atopic asthma and SIT leads to apoptosis/anergy of T cells and induces immune-regulatory responses and immune deviation towards Th1. Many factors can affect the safety and efficacy of SIT, such as pattern of sensitization, allergy vaccine (allergen extracts, adjuvants and conjugated molecules), route of administration (subcutaneous or sublingual) and different treatment schedules. Overall, asthma symptoms and medication scores usually decrease following a SIT course and the most common observed side effects are restricted to local swelling, erythema and pruritus. Compared with conventional pharmacotherapy, SIT may be more cost effective, providing a benefit after discontinuation and a steroid-sparing effect. In addition, it can prevent new sensitizations in monosensitized asthmatic children. Microbial supplements such as probiotics, immunomodulatory substances like anti-IgE/leukotrienes, antibodies and newer allergen preparations such as recombinant forms have been tested to improve the efficacy and safety of SIT with inconclusive results. In conclusion, SIT provides an appropriate solution for childhood asthma that should be employed more often in clinical practice. Further studies are awaited to improve current knowledge regarding the mechanisms behind SIT and determine the most appropriate materials and schedule of immunotherapy for children with asthma.

Specific immunotherapy in asthma: a comprehensive review

BACKGROUND

The prescription of allergen immunotherapy (SIT) in asthma remains a matter of debate and official guidelines often do not provide clear recommendations in this regard.

METHODS

An extensive review of the literature was untaken.

RESULTS

There are many robust studies with SCIT and SLIT showing positive results related to improving asthma symptoms, in particular when asthma was associated with rhinitis. In addition, there are several favourable meta-analyses, although their validity is limited by the heterogeneity of the trials included. The disease modifying effect of SIT (prevention of asthma onset and long-lasting effects) should be considered when prescribing this treatment. Regarding safety, fatalities seem to be rare: in Europe no fatality has been reported over the last two decades, and the same has been observed in USA in the last 4 years. Uncontrolled asthma is universally recognized as the most important risk factor for severe adverse events, but there is no clear demonstration that SIT can worsen or induce asthma. In contrast, of the few studies specifically designed to evaluate asthma, none had a formal sample size calculation, and pulmonary function was assessed as primary outcome only sporadically.

CONCLUSIONS

According to the presently available evidence, SLIT and SCIT can be used in asthma associated with rhinitis (the most common condition), provided that asthma is adequately controlled by pharmacotherapy. In such cases, a measurable clinical benefit on asthma symptoms can be expected. SIT cannot be presently recommended as single therapy when asthma is the unique manifestation of respiratory allergy.

An evidence-based analysis of house dust mite allergen immunotherapy: a call for more rigorous clinical studies

BACKGROUND

According to meta-analyses and reviews, subcutaneous allergen immunotherapy (SCIT) and sublingual allergen immunotherapy (SLIT) are beneficial in patients with allergic rhinitis (AR) and allergic asthma (AA) induced by house dust mites (HDMs). However, the reported effect sizes have varied greatly from one study to another.

OBJECTIVE

We sought to perform an evidence-based medicine assessment of commercially available SCIT and SLIT formulations in patients with HDM-induced AA and HDM-induced AR.

METHODS

We searched for double-blind, placebo-controlled randomized clinical trials and analyzed study designs, doses, regimens, patient-reported outcomes, safety reporting, and compliance.

RESULTS

Forty-four studies met our inclusion criteria. Some studies tested both SLIT and SCIT or scored both AA and AR outcomes; therefore we reviewed 35 treatment arms in patients with AA (20 for SCIT and 15 for SLIT) and 23 treatment arms in patients with AR (7 for SCIT and 16 for SLIT). The treatment duration ranged from 6 weeks to 3 years. For SCIT, the dose of Der p 1 major allergen (when reported) ranged from 7 to 30 μg for maintenance doses and 60 to 420 μg for cumulative doses. For SLIT, the doses of Der p 1 (when reported) were 0.8 to 70 μg for maintenance doses and 60 to 23,695 μg for cumulative doses. Safety data were often absent or poorly reported. A statistically significant active versus placebo symptom score was observed more frequently for SCIT than for SLIT.

CONCLUSION

There is no consensus on basic treatment parameters (eg, dose and duration) in HDM SCIT and SLIT. There is an urgent need for rigorous, long-term, double-blind, placebo-controlled randomized clinical trials with an efficacy criterion that reflects the particular features of HDM-induced allergic disease.

Allergen immunotherapy for house dust mite: clinical efficacy and immunological mechanisms in allergic rhinitis and asthma

INTRODUCTION

There is an increasing prevalence of atopic diseases such as allergic rhinitis and asthma with house dust mite (HDM) being the common allergen that is highly associated with allergic rhinitis and asthma. Allergen avoidance and pharmacotherapy are part of treatment but it has proved difficult to change the course of HDM-related allergic diseases. Allergen immunotherapy (AIT) has been in use for the past century and has been shown to be effective in the treatment of allergic respiratory disease.

AREAS COVERED

This review exclusively focuses on HDM-AIT and discusses the differences in clinical efficacy and safety, long-term effect after discontinuation and immunological changes observed in both HDM-subcutaneous immunotherapy (SCIT) and HDM-sublingual immunotherapy (SLIT) in the treatment of allergic rhinitis and asthma in both pediatric and adult populations.

EXPERT OPINION

The majority of studies involved small numbers of patients, variable doses of major allergens and are of variable quality. There is good evidence for HDM-SCIT efficacy and its long-term effect in adults and children, whereas at the present time, evidence for HDM-SLIT is unconvincing, particularly in children. In carefully selected patients, HDM-SCIT is effective and safe. More definitive trials are needed before HDM-SLIT can be recommended in routine practice for rhinitis and/or asthma.

Sublingual immunotherapy in children with allergic rhinoconjunctivitis mono-sensitized to house-dust-mites: a double-blind-placebo-controlled randomised trial

BACKGROUND

Although sublingual immunotherapy (SLIT) has been demonstrated to be a safe and efficient treatment in children with seasonal allergic rhinitis (AR), there is little evidence on the efficacy of SLIT with house-dust-mite (HDM) extract in children with isolated perennial AR.

OBJECTIVES

We sought to assess the clinical efficacy and safety of HDM-SLIT in children with isolated allergic rhinitis-conjunctivitis mono-sensitized to HDM without asthma symptoms.

METHODS

Twenty-two children (aged 5-10 years) with perennial AR and conjunctivitis symptoms mono-sensitized to Dermatophagoides pteronyssinus and Dermatophagoides farinae were enrolled. During a 2 months run-in period, symptom and medication scores, lung functions, bronchial hyperreactivity, nasal provocation and skin prick tests were evaluated. Subjects were randomized to active or placebo using a double-blind method. A total of eighteen subjects were randomised to receive either active SLIT or placebo for 12 months. Daily symptom and medication scores, baseline lung functions, bronchial hyperreactivity, nasal provocation and skin prick tests were recorded and re-evaluated at the end of treatment.

RESULTS

After one year of treatment, no significant differences were detected in the between groups and within group comparisons based on total rhinitis symptom/medication scores (p > 0.05). Skin reactivity to Dermatophagoides pteronyssinus was significantly reduced in HDM-SLIT compared to placebo group (p = 0.018). A significant reduction in nasal sensitivity was observed in SLIT group after one year treatment when compared to baseline (p = 0.04). Total conjunctivitis symptoms were reduced significantly in both active and lacebo group at the end of treatment compared to baseline. The proportion of patients with non-specific bronchial hyperreactivity increased to almost 3-fold in placebo group compared to baseline.

CONCLUSION

HDM-SLIT was not superior to placebo in reducing isolated rhinoconjunctivitis symptoms within 12 months of treatment. However, HDM-SLIT has a modulating effect on allergen-specific nasal and skin reactivity in isolated perennial AR children.

CLINICAL TRIAL REGISTRATION

The trial was registered at Anzctr.org.au number, ACTRN12613000315718.

The contribution of sublingual immunotherapy to the achievement of control in birch-related mild persistent asthma: a real-life randomised trial

BACKGROUND

Asthma control represents the main goal of asthma management and different strategies aim to avoid the long term downsides of inhaled corticosteroids. We investigated in real-life conditions the contribution of sublingual immunotherapy in achieving the control of birch-related mild persistent asthma compared to two usual step-up therapeutic options.

METHODS

A three-year open randomised study included 84 asthmatics, uncontrolled during the previous birch pollen season, despite a treatment with budesonide 400μg/day. Patients randomly received budesonide 800μg/day, budesonide 1600μg/day, budesonide 400μg/day plus montelukast 10μg/day and budesonide 400μg/day plus carbamylated allergoid of betulaceae pre-coseasonally. Asthma Control test, combined allergy symptoms and medications score, albuterol consumption, lung function, nasal eosinophils and nasal steroids usage were assessed as changes from the first to last pollen season.

RESULT

Seventy-six patients concluded the study. All options, except budesonide 800μg/day, produced an improvement of mean monthly Asthma Control test (p<0.05). Patients undergoing low-dose budesonide plus immunotherapy achieved, after three years, an appreciable control (ACT mean score 24). A significant improvement was seen in all groups for allergy symptoms plus medications and bronchial reactivity. Albuterol consumption and lung function improved in all but the first group. Only budesonide plus immunotherapy reduced nasal eosinophils and nasal steroids usage. Two mild self-resolving adverse events were reported.

CONCLUSIONS

For patients with respiratory allergy due to birch pollen and mild persistent asthma, sublingual immunotherapy added to low-dose inhaled corticosteroids appears effective in maintaining long-term seasonal asthma control, representing a safe opportunity to reduce the cumulative amount of delivered corticosteroids.

Evaluation of clinical and immunological responses: a 2-year follow-up study in children with allergic rhinitis due to house dust mite

Background. Allergic rhinitis is a disease with polarization towards Th₂ and a defect of regulatory T cells. Immunological changes have been reported after immunotherapy treatment. However, there is not much known about the natural course of allergic rhinitis with respect to clinical manifestation and the relation with immunological responses. Objective. To evaluate clinical symptoms of allergic rhinitis, in relation to in vivo allergen-specific skin responses and in vitro allergen-specific effector and regulatory T cells determined at baseline and after two years. Methods. From a large trial, 59 children were randomly selected. The following variables were compared: clinical symptoms, allergen skin tests, specific IgE, T-cell proliferation, IL-5, IL-13, IFN-gamma, IL-10, TGF-beta, CD4⁺CD25^hi cells, and Foxp3 expression. Results. Allergic symptoms had decreased after two years. Whereas skin test reactions correlated between years 0 and 2, there was no change in the size of the reaction. Also, proinflammatory reactions did not change after two years, with a positive correlation between years 0 and 2. No relevant changes were observed with respect to regulatory cells. Conclusion. Whereas, comparable to immunotherapy, allergic complaints decrease, the immunological changes of specific T-cell activity (both effector cells and regulator cells) which are observed after immunotherapy, do not change.