Dropouts in sublingual allergen immunotherapy trials - a systematic review

Retrospective Observational Study on Telemedicine in Sublingual Immunotherapy for Patients with Japanese Cedar Pollinosis and House Dust Mite Allergic Rhinitis

Introduction: In Japan, telemedicine has gradually expanded due to deregulation in response to the COVID-19 pandemic. However, its current status remains unclear, as it is primarily provided by general practitioners. This study aims to examine the use of telemedicine in sublingual immunotherapy (SLIT) for patients with Japanese cedar pollen allergy and/or house dust mite allergic rhinitis. Methods: We conducted a retrospective analysis of medical record data from seven otorhinolaryngology clinics and performed an exploratory evaluation between a group that combined telemedicine and in-person visits during the initial 6 months of SLIT and another group with only in-person visits. Results: Following propensity score matching, 51 and 82 patients were eligible for the telemedicine and in-person groups, respectively, with 33 cases in both groups. Both groups had similar characteristics after matching. No significant difference was found in the withdrawal rate at 6 months from the start of SLIT (6.1% and 9.1% in each group; p = 1.00), side effects, or treatment efficacy between the two groups. The average copayment for patients tended to be significantly higher in the telemedicine group after one, three, and 6 months following SLIT initiation. Discussion: The situation of patients who receive an appropriate combination of telemedicine and in-person visits is not significantly different from patients who receive in-person visits alone. This study may help indicate the actual status of telemedicine in Japan. Further investigation at more facilities is necessary in the future to dispel concerns in the practice setting.

Patient compliance to sublingual immunotherapy for mite-induced allergic rhinitis: A retrospective study

Background

Compliance to sublingual immunotherapy (SLIT) is generally low, resulting in reduced short- and long-term clinical efficacy. Compliance is a critical factor determining the success of allergic rhinitis (AR) treatment.

Objective

To analyze the compliance of patients with house dust mite (HDM)-induced AR to SLIT and the impact of coronavirus disease 2019 (COVID-19) on compliance.

Methods

The clinical data of 3117 patients with HDM-induced AR who started SLIT between July 2018 and April 2022 were retrospectively reviewed. We assessed the reasons for non-compliance and the changes in non-compliance during the COVID-19 pandemic compared to the pre-pandemic period.

Results

Of 3117 patients, 507 (16.27%) patients (ages, 5-67 years) were identified as non-compliant. The most common reason for non-compliance was poor efficacy (27.22%). The non-compliance rate was highest during 24-36 months of SLIT (28.13%, 153/544), followed by 12-24 months (7.02%, 91/1296). Non-compliance was significantly higher in adolescents/adults than in children (P = 0.000). Although the generalized linear model analysis indicated that compliance was affected by the COVID-19 pandemic during 3-6 months of SLIT, the overall compliance to SLIT was not significantly affected by the pandemic, according to the Kaplan-Meier survival analysis.

Conclusions

The non-compliance rate of SLIT in this study was low, and poor efficacy was the most common reason for non-compliance. The compliance of adolescents/adults was lower than that of children. The COVID-19 pandemic did not significantly impact compliance to SLIT, which is an appropriate strategy for the home treatment of AR patients during major public health events.

Current Management of Allergic Rhinitis

Allergic rhinitis (AR) is the most common allergic disease worldwide and one of the most common chronic diseases in general. Allergic rhinitis is caused by inhalant allergens from outdoor and indoor environments with varying significance of different allergens in global regions. We provide options for the current management for AR including pharmacological treatments and nonpharmacological options and allergen immunotherapy (AIT). A literature review has been conducted in Medline, Pubmed, as well as the national and international study (ClinicalTrials.gov) and guideline registers and the Cochrane Library. Human studies published on the topic in the period up to and including November 2023 were taken into account. Allergen avoidance measures, pharmacotherapy, and AIT are the cornerstones of AR treatment. Nonpharmacological measures and behavioral recommendations should be adequately added. Tools of precision medicine are already playing a significant role and will be part of the diagnostic and therapeutic standard in the future. Patients benefit most in a network of different pharmacological and nonpharmacological treatment measures including AIT. Application of precision medicine tools for diagnosis and treatment will improve standards of care.

Tolerability and Safety of Sublingual Immunotherapy in Patients with Tree Pollen Allergy in Daily Practice-An Open, Prospective, Non-Interventional Study

To investigate the tolerability and safety of two sublingual tree pollen extracts approved in 2018, a non-interventional study (NIS) was performed. This NIS was an 8-month observational study conducted at 84 sites throughout Germany. Study participants received either a sublingual liquid allergen extract of birch pollen (SBPE) or a liquid allergen extract consisting of a mixture of birch, hazel, and alder tree pollen (STPE). Data from 432 patients were analyzed for the occurrence of adverse events and patient compliance. At least one local reaction occurred in 69 (22.2%) patients, whereas systemic reactions were only observed in 27 (6.3%) patients. STPE-treated patients developed systemic reactions more frequently than SBPE-treated patients (SBPE: 9 (4.3%) vs. STPE: 18 (8.0%)). Only one patient developed a systemic grade III reaction. Severe systemic grade IV reactions were not observed. A total of 348 (98.6%) of the patients who completed all visits were satisfied or very satisfied with the sublingual immunotherapy (SLIT), and 322 (71%) patients completed all visits. Both investigated products were well tolerated by the patients and demonstrated a good safety profile. AEs were observed less frequently than in the preceding clinical phase III trial, and no new safety concerns were identified.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Current treatment strategies for seasonal allergic rhinitis: where are we heading?

INTRODUCTION

Allergic rhinitis (AR) is very commonly caused by pollens. The symptoms of AR consist of sneezing, nasal congestion, rhinorrhea, nasal itching and airflow obstruction. The diagnosis has long been based on clinical history, skin prick tests and in vitro measurement of specific IgE, but the innovative approach of precision medicine has made diagnostic tools of much greater accuracy available.

AREAS COVERED

This review covers the advances in the treatment of seasonal AR concerning the drugs to be used according to the grade of disease and the characteristics of the patients, and the role of allergen immunotherapy (AIT), which is the only treatment capable of acting, in addition to the symptoms, on the cause of AR and therefore to modify its natural history.

EXPERT OPINION

Drug treatment of AR include a large number of agents, the choice of which depends on the severity of the disease. AIT has high evidence of efficacy demonstrated by meta-analyses, and further improvement is currently apparent, as for diagnosis, applying the means of precision medicine. However, when AIT is performed in current practice, without the strict rules of controlled trials, long-term low adherence is a major problem to be solved.

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

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

The Road Toward Transformative Treatments for Food Allergy

A series of landmark studies have provided conclusive evidence that the early administration of food allergens dramatically prevents the emergence of food allergy. One of the greatest remaining challenges is whether patients with established food allergy can return to health. This challenge is particularly pressing in the case of allergies against peanut, tree nuts, fish, and shellfish which are lifelong in most patients and may elicit severe reactions. The standard of care for food allergy is allergen avoidance and the timely administration of epinephrine upon accidental exposure. Epinephrine, and other therapeutic options like antihistamines provide acute symptom relief but do not target the underlying pathology of the disease. In principle, any transformative treatment for established food allergy would require the restoration of a homeostatic immunological state. This may be attained through either an active, non-harmful immune response (immunological tolerance) or a lack of a harmful immune response (e.g., anergy), such that subsequent exposures to the allergen do not elicit a clinical reaction. Importantly, such a state must persist beyond the course of the treatment and exert its protective effects permanently. In this review, we will discuss the immunological mechanisms that maintain lifelong food allergies and are, consequently, those which must be dismantled or reprogrammed to instate a clinically non-reactive state. Arguably, the restoration of such a state in the context of an established food allergy would require a reprogramming of the immune response against a given food allergen. We will discuss existing and experimental therapeutic strategies to eliminate IgE reactivity and, lastly, will propose outstanding questions to pave the road to the development of novel, transformative therapeutics in food allergy.

Dropouts From Sublingual Immunotherapy and the Transition to Subcutaneous Immunotherapy in House Dust Mite-Sensitized Allergic Rhinitis Patients

Purpose: Both subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) are effective in reducing symptoms and medication scores and inducing long-term efficacy in patients with allergic rhinitis (AR). However, SLIT has been associated with poor patient adherence. This study investigates the factors impacting dropout rates from SLIT in house dust mite (HDM)-sensitized AR patients.

Methods: A retrospective study was performed to analyze dropout rates and reasons in AR patients receiving Dermatophagoides farinae (Der f) SLIT with a follow-up period of 2 years.

Results: A total of 719 HDM-sensitized AR patients received Der f-SLIT. Dropout rates increased with time and most occurred after 1 year of SLIT. By month 24, 654 (91%) patients had discontinued SLIT. The dropout rates by month 24 were 100, 90.1, and 91.1% in children <5 years old, children aged 5–18 years old, and adults ≥ 18 years old, respectively. Combination with allergic asthma and mono- or multi-sensitization to other aeroallergens did not affect the dropout rates. The most common self-reported reasons for dropouts were refusal of continuation, dissatisfaction with the efficacy, transition to SCIT, and adverse effects. Refusal of continuation increased with age, whereas transition to SCIT decreased with age. Ninety-seven cases transitioned from SLIT to SCIT, and the transition rates increased with time. Comorbid allergic asthma did not affect the transition rates. However, multi-sensitization was associated with a slightly higher rate of transition to SCIT. The most common reason for the transition was dissatisfaction with the efficacy (54.6%), which was only reported by patients older than 5 years. For children who began SLIT at younger than 5 years old, the most common reason (81.2%) for transition was age reaching 5 years.

Conclusions: HDM-SLIT has a very high dropout rate, which is mainly due to refusal of continuation and dissatisfaction with the efficacy. Transitioning from SLIT to SCIT may help keep these patients on AIT and thus increase adherence and long-term efficacy.

Cost-effectiveness of grass pollen allergen immunotherapy in adults

BACKGROUND

Major scientific societies, such as the EAACI or the AAAAI, do not express any suggestion on which form of allergen immunotherapy (AIT) is to be preferred (subcutaneous immunotherapy, SCIT, vs sublingual immunotherapy, SLIT). This choice could depend on their relative pharmacoeconomic value.

OBJECTIVE

To assess the cost-effectiveness of AIT for grass pollen, administered as SCIT or SLIT.

METHODS

We created a Markovian Model, to evaluate, in a hypothetical cohort of adult patients suffering from moderate-to-severe rhino-conjunctivitis with or without allergic asthma, the cost-effectiveness of SLIT (tablets, Grazax^® and Oralair^® ) or SCIT (various currently available products, plus indirect nonmedical costs, such as travel and productivity costs) in addition to pharmacological therapy, assuming a 9-year horizon to capture AIT long-term effects. The incremental cost-effectiveness ratio (ICER) was calculated assuming pharmacological therapy as the reference comparator.

RESULTS

In the base case, SCIT was slightly more expensive, but more effective than SLIT, being the most cost-effective option (ICER for SCIT, €11 418; ICER for SLIT, €15 212). ICERs greater than €120 000 for both SCIT and SLIT were demonstrated in a scenario assuming that low treatment persistence rates, which are common in real-life, lead to absence of long-term AIT clinical benefit. Considering indirect nonmedical costs SLIT resulted more cost-effective than SCIT (ICER for SCIT, €17 318; ICER for SLIT, €15 212).

CONCLUSION

In daily practice, AIT for grass pollens may be a cost-effective option only in patients with low discontinuation rates. SCIT, which is less affected by this limitation than SLIT, seems the most cost-effective AIT form.

An analysis of factors associated with compliance and dropout of sublingual immunotherapy on Japanese cedar pollinosis patients

BACKGROUND

Sublingual immunotherapy (SLIT) is safe and effective but compliance is problematic. In this study we evaluated dropout and compliance among adults (≥20 years of age) and adolescents (<20 years of age) for Japanese cedar pollen extract (JCPE), an aqueous SLIT approved in 2014 in Japan.

METHODS

Administrative claims data on 1236 Japanese patients, 846 adults (mean age, 43.0 years; 41.8% female) and 249 adolescents (mean age, 14.1 years; 36.6% female), with a JCPE prescription between October 2014 and June 2016 were reviewed. Adults and adolescents were divided according to the year they started SLIT (1- and 2-year cohorts) to calculate dropout and compliance and identify associated factors using multivariate Cox and linear regression models.

RESULTS

In 1- and 2-year adult cohorts, dropout rates were 13.5% and 22.1% and compliance rates were 92.8% and 88.8%, respectively. Adolescents had higher dropout and lower compliance. Patients 40-59 years of age had a lower dropout risk than patients 20-29 years of age. Dropout hazard ratios (95% confidence interval) in 1- and 2-year cohorts were 0.26 (0.12-0.58) and 0.40 (0.17-0.93) in patients 40-49 years of age and 0.32 (0.14-0.75) and 0.35 (0.13-0.92) in patients 50-59 years of age, respectively. Younger age contributed to lower compliance in 1- and 2-year adult cohorts (p = 0.001 and p = 0.02, respectively). Systemic steroidal medication history and male gender were positively associated with compliance in adults but not in adolescents.

CONCLUSION

High dropout rate was associated with younger generations. Compliance in adults, but not in adolescents, was associated with age, systemic steroidal medication history, and gender.

EAACI Guidelines on Allergen Immunotherapy: Allergic rhinoconjunctivitis

Allergic rhinoconjunctivitis (AR) is an allergic disorder of the nose and eyes affecting about a fifth of the general population. Symptoms of AR can be controlled with allergen avoidance measures and pharmacotherapy. However, many patients continue to have ongoing symptoms and an impaired quality of life; pharmacotherapy may also induce some side-effects. Allergen immunotherapy (AIT) represents the only currently available treatment that targets the underlying pathophysiology, and it may have a disease-modifying effect. Either the subcutaneous (SCIT) or sublingual (SLIT) routes may be used. This Guideline has been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Taskforce on AIT for AR and is part of the EAACI presidential project "EAACI Guidelines on Allergen Immunotherapy." It aims to provide evidence-based clinical recommendations and has been informed by a formal systematic review and meta-analysis. Its generation has followed the Appraisal of Guidelines for Research and Evaluation (AGREE II) approach. The process included involvement of the full range of stakeholders. In general, broad evidence for the clinical efficacy of AIT for AR exists but a product-specific evaluation of evidence is recommended. In general, SCIT and SLIT are recommended for both seasonal and perennial AR for its short-term benefit. The strongest evidence for long-term benefit is documented for grass AIT (especially for the grass tablets) where long-term benefit is seen. To achieve long-term efficacy, it is recommended that a minimum of 3 years of therapy is used. Many gaps in the evidence base exist, particularly around long-term benefit and use in children.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

Specific immunotherapy in allergic rhinitis

Allergic rhinitis is a common condition, with significant impact on quality of life depending on severity and quality of control. Allergen-specific immunotherapy (allergen-SIT) is the only known treatment able to alter the natural course of allergic rhinitis. Although well known to allergologists, it has yet to be fully adopted by the ENT community. This review, based on the most recent meta-analyses and clinical studies, shows that SIT significantly reduces symptoms and medication requirements (nasal corticosteroids, H1-antihistamines) in allergic rhinitis. It can reduce the risk of progression to asthma and, if initiated early enough, of developing new sensitizations. Immunobiological analysis shows an altered inflammatory profile following SIT, with immune tolerance involving T-regulatory lymphocyte induction and IgG production. Sublingual SIT with drops is as effective as subcutaneous SIT and is simpler to use, with less anaphylactic risk. Standardization of trial protocols in terms of treatment response assessment and side effect grading is recommended to improve comparative studies. Sublingual SIT with tablets has recently been introduced, providing a good opportunity for ENT practitioners to adopt the SIT approach in rhinitis triggered by allergy to pollens and, in the near future, to house dust mites.

Nonadherence to sublingual immunotherapy in allergic rhinitis: a real-life analysis

BACKGROUND

To sustain the long-lasting beneficial effects of allergen-specific sublingual immunotherapy (SLIT), an adequate duration of treatment is required. Nevertheless, many patients discontinue prematurely and therefore fail to obtain satisfactory therapeutic effect in clinical practice. The aim of this study was to analyze the causes leading to premature discontinuation of SLIT in allergic rhinitis (AR), and to provide the corresponding countermeasures for the following SLIT course.

METHODS

We performed a retrospective analysis of data from 142 patients with AR who started SLIT during the period from December 2009 to February 2015. Patients were contacted at 1, 3, 6, and 12 months into SLIT as part of our standard of care. The patients who claimed to have stopped treatment were asked to provide a reason during one of the phone calls.

RESULTS

Overall, 76 (54%) patients with AR terminated immunotherapy during the first year of treatment. Among the 76 patients, the following reasons were cited for nonadherence to immunotherapy: patients could not be reached (25%); ineffectiveness (24%); the long course (18%); improvement of symptoms (13%); side effects (4%); lack of confidence in the treatment (4%); or other reasons (12%).

CONCLUSION

Fifty-four percent of AR patients terminated their treatment within the first year of SLIT. The top reasons for treatment discontinuation included patients not be reached, ineffectiveness, and length of course.

Allergen-Specific Immunotherapy

Allergen-specific immunotherapy remains the only causal treatment of allergic disease to date. Its efficacy in symptom reduction was demonstrated in double blind, placebo-controlled studies of allergic rhinoconjunctivitis, allergic asthma, and Hymenoptera venom hypersensitivity, including long-term effects after discontinuation of treatment. In addition, immunotherapy decreases the risk of developing new sensitisations to aeroallergens in monosensitised patients and allergic asthma in patients with mere allergic rhinitis. The mechanism of immunotherapy entails redirection of the T lymphocyte response from a T helper cell Type 2 phenotype in favour of induction of regulatory T cells and/or immune deviation toward a T helper cell Type 1 phenotype, with resulting inhibition of downstream effector pathways and induction of immunoglobulin G-associated blocking antibodies. Two main application forms are used in clinical practice: subcutaneous immunotherapy and sublingual immunotherapy. The advantage of subcutaneous immunotherapy is its proven efficacy over a broad range of indications. Disadvantages are systemic allergic reactions and inconvenience for the patient due to frequent doctor visits. Sublingual immunotherapy has been shown to result in less systemic allergic reactions and may be more convenient due to home application; however, efficacy has only been proven for allergic rhinitis. For clinicians, the adherence to practice guidelines and thorough knowledge of allergen products, application routes, indications, immunomodulatory mechanisms, efficacy, safety, and cost-effectiveness is important for successful treatment and will be addressed in this review article.

Current and Emerging Therapies for IgE-Mediated Food Allergy

Food allergies are a growing clinical problem leading to increased health care utilization and decreases in patient quality of life. Current treatment recommendations include strict dietary avoidance of the offending food as well as use of self-injectable epinephrine in case of accidental exposure with allergic reaction. Although many individuals will eventually outgrow their food allergies, a substantial number will not. Significant effort has been made to find novel treatments that protect patients from food-triggered reactions as well as to develop immune-modulating therapies that could lead to tolerance. In this review, three therapies that have shown the most promise for the treatment of food allergies are highlighted: oral immunotherapy, sublingual immunotherapy, and epicutaneous immunotherapy.

Adherence to Sublingual Immunotherapy

Adherence is a major issue in any medical treatment. Allergen immunotherapy (AIT) is particularly affected by a poor adherence because a flawed application prevents the immunological effects that underlie the clinical outcome of the treatment. Sublingual immunotherapy (SLIT) was introduced in the 1990s, and the early studies suggested that adherence and compliance to such a route of administration was better than the traditional subcutaneous route. However, the recent data from manufacturers revealed that only 13% of patients treated with SLIT reach the recommended 3-year duration. Therefore, improved adherence to SLIT is an unmet need that may be achieved by various approaches. The utility of patient education and accurate monitoring during the treatment was demonstrated by specific studies, while the success of technology-based tools, including online platforms, social media, e-mail, and a short message service by phone, is currently considered to improve the adherence. This goal is of pivotal importance to fulfill the object of SLIT that is to modify the natural history of allergy, ensuring a long-lasting clinical benefit, and a consequent pharmaco-economic advantage, when patients complete at least a 3-year course of treatment.

Persistence of treatment with 5-grass pollen tablets in patients with allergic rhinitis: a real-life study

BACKGROUND

In patients with allergic rhinitis, treatment adherence to allergen immunotherapy varies greatly in randomized and real-life studies.

OBJECTIVE

To evaluate the use of a 5-grass pollen tablet as sublingual immunotherapy, its treatment persistence, and the reasons for discontinuation in a real-life clinical setting.

METHODS

This multicenter, prospective, open-label, noncontrolled observational study evaluated the use of sublingual immunotherapy with a 5-grass pollen tablet in a cross-sectional population of patients (≥5 years old) with grass pollen-induced allergic rhinitis with or without asthma. The primary objective was to determine the percentage of patients persisting with treatment across 1 season in a pre-co-seasonal scheme. Secondary objectives included evaluation of reasons for treatment discontinuation, safety and adverse events; effectiveness (based on physician and patient assessments), and treatment compliance.

RESULTS

The study included 196 patients (49.2% male, mean age 27.5 years, range 5.3-65.7 years), with treatment provided by 47 participating physicians. Sixty-seven percent of patients had polysensitivity and 32% had coexistent asthma. On average, patients were treated for 7 months with the 5-grass pollen tablet. After 1 month, 85% of all patients persisted with treatment, and 70% persisted after 7 months. Treatment discontinuation was due chiefly to known side effects (mild to moderate local allergic reactions). Most patients reported symptom improvement; 80% of all patients intended to continue treatment next season.

CONCLUSION

Most patients with allergic rhinitis treated pre-co-seasonally with a 5-grass pollen tablet persisted with treatment after the first pollen season. Patients were willing to continue their treatment in the following season owing to improvement of symptoms.

Prospective adherence to specific immunotherapy in Europe (PASTE) survey protocol

BACKGROUND

Adherence to allergen immunotherapy is important for its effectiveness. There is currently limited data available on allergen immunotherapy adherence outside of clinical trials i.e. in real-life clinical practice. As part of a European Academy of Allergy and Clinical Immunology Immunotherapy Interest group initiative, we endeavoured to design a survey in order to prospectively evaluate adherence to subcutaneous and sublingual immunotherapy across different European countries.

METHOD/DESIGN

The inclusion criteria for this prospective, multi-country survey were set as: adults, starting clinically indicated allergen immunotherapy for respiratory allergic disorders or Hymenoptera venom allergy. An online survey was designed in order to enrol participants and assess adherence to immunotherapy. Eight countries (Czech Republic, Georgia, Germany, Greece, Italy, Poland, Portugal, Spain) were selected to reflect different parts of Europe and differences in allergens and routes of immunotherapy administration. Each country has an allocated National co-ordinator that has identified local Allergy departments willing to enrol participants in this survey. Each participant will be followed up for a total of three years. In order to assess adherence, a 4-monthly follow-up form detailing any missed doses and reasons will be completed online. In case of a participant discontinuing treatment, reasons for this will be recorded.

DISCUSSION

The use of online survey software has enabled us to make this survey a reality and reach clinicians in different countries. Forty-five centres have enrolled a total of over 1,350 participants. It is hoped that this prospective real life survey will enable us to gain a better understanding of reasons that affect adherence to subcutaneous and sublingual immunotherapy and assist in developing ways to improve this.

Immune mechanisms of sublingual immunotherapy

Sublingual immunotherapy (SLIT) is a well-established allergen-specific immunotherapy and a safe and effective strategy to reorient inappropriate immune responses in allergic patients. SLIT takes advantage of the tolerogenic environment of the oral mucosa to promote tolerance to the allergen. Several clinical studies have investigated the complex interplay of innate and adaptive immune responses that SLIT exploits. The oral immune system is composed of tolerogenic dendritic cells that, following uptake of allergen during SLIT, support the differentiation of T helper cell type 1 (Th1) and the induction of IL-10-producing regulatory T cells. Following SLIT, allergic disease-promoting T helper cell type 2 (Th2) responses shift to a Th1 inflammatory response, and IL-10 and transforming growth factor (TGF)-β production by regulatory T cells and tolerogenic dendritic cells suppress allergen-specific T cell responses. These immune changes occur both in the sublingual mucosa and in the periphery of a patient following SLIT. SLIT also promotes the synthesis of allergen-specific IgG and IgA antibodies that block allergen-IgE complex formation and binding to inflammatory cells, thus encouraging an anti-inflammatory environment. Several of these revealing findings have also paved the way for the identification of biomarkers of the clinical efficacy of SLIT. This review presents the emerging elucidation of the immune mechanisms mediated by SLIT.