The European Survey on Adverse Systemic Reactions in Allergen Immunotherapy (EASSI): A paediatric assessment

Allergen immunotherapy adverse events in adults with respiratory allergies-data from ADER: An EAACI task force report

BACKGROUND

Registries can yield important insights on allergen immunotherapy (AIT) outcomes in daily clinical practice. However, systematic recordings of adverse events (AE) due to AIT in real-life are lacking.

METHODS

The Allergen Immunotherapy Adverse Events Registry (ADER) is a prospective, multicenter registry on real-life AIT safety. Data on adults (>18 years old) with respiratory allergies receiving AIT with mites, pollens, epithelia, and/or molds were retrieved and analyzed from ADER. The frequency, characteristics and risk factors of AE were investigated. The MedDRA terminology was used to record AE.

RESULTS

A total of 1545 individuals with a mean age of 33 ± 10 years receiving 1815 AIT courses (n = 1060 sublingual (SLIT); n = 755 subcutaneous (SCIT)) in centers from eight countries were included. Patients had allergic rhinitis (65%) or, asthma only (3.7%) or rhinitis with asthma (31.2%). Grass was the most frequent specific sensitizer (60.7%), followed by mites (45.5%), birch pollen (20.6%), epithelia (16.1%), and molds (8%). There were 296 AE recorded in 115 patients (7.4%). A higher frequency of AE occurred during up-dosing (59%) compared to maintenance. Severe reactions were rare (0.2%), all in the context of SCIT. After 6 weeks of maintenance only one moderate AE was recorded. The most frequently reported symptoms were from the respiratory system and the skin. Having asthma, doing SCIT, AIT with mugwort, cat, or birch were associated with higher risk for AE while the use of allergoids induced lower risk.

CONCLUSION

In real life clinical practice, AIT-associated AE occur in a minority of patients, while severe reactions are rare. The presence of asthma and use of SCIT are risk factors, while the use of modified allergens lowers the risk.

Allergen immunotherapy-induced anaphylaxis: Data from the European Anaphylaxis Registry

BACKGROUND

Data on anaphylaxis due to allergen immunotherapy (AIT) are limited. This study assessed AIT-induced anaphylaxis using data from the European Anaphylaxis Registry.

OBJECTIVE

To analyze the characteristics, symptoms, severity, and emergency management of AIT-induced anaphylactic reactions across age groups and the administered allergenic source.

METHODS

Data were obtained from 54 allergy centers across 10 European countries from 2007 to 2023. Anaphylactic reactions involving at least 2 organ systems were analyzed for symptoms, severity, associated diseases, administration routes, and emergency treatment. Statistical methods included χ2 and Fisher's exact tests.

RESULTS

AIT accounted for 1.1% of the cases in the anaphylaxis registry (173/15,748), of which 1.8% were pediatric and 0.7% were adults. Respiratory symptoms were more frequent in children/adolescents (92%) than in adults (66%) among AIT-related anaphylaxis, whereas cardiovascular and gastrointestinal symptoms were more common in adults (40% vs 78% and 20% vs 42%, respectively). Only a few sublingual immunotherapy-related cases were documented, including 2 grade III reactions, with no fatalities (sublingual immunotherapy [n = 8] vs subcutaneous immunotherapy (SCIT) [n = 153]). One fatality due to SCIT was reported (grass pollen). Delayed reactions (>30 minutes) were reported in 22 cases, predominantly after SCIT. All delayed grade III reactions that occurred more than 120 minutes were reported in children. Adrenaline was underused in emergency management and administered in 30% of grade II and 50% of grade III reactions.

CONCLUSION

Our study highlights the importance of age-specific monitoring and appropriate emergency treatment to enhance patient safety during AIT.

Efficacy and safety of subcutaneous immunotherapy combined with omalizumab in children with dust mite-induced asthma

OBJECTIVE

To evaluate the benefits of combining omalizumab with specific immunotherapy (SCIT) in the treatment of children with bronchial asthma.

METHODS

In this study, 83 children with asthma were treated at the Allergy Department of Qingdao University from January 2019 to February 2020. Participants were divided into three groups: SCIT, combination (omalizumab + SCIT), and control (standard asthma medications). We assessed Asthma Control Questionnaire (ACQ) scores, Visual Analogue Scale (VAS) scores, and lung function at baseline, 24 wk, and 48 wk. Additionally, asthma medication scores were compared at 24 and 48 wk. Adverse reactions were monitored in both the SCIT and combination groups.

RESULTS

The combination group demonstrated lower ACQ scores at both 24 and 48 wk, and improved VAS scores at 48 wk compared to the other groups. Additionally, lung function parameters (FEV1 and FEF50) showed significant improvement in the combination group. Reduced asthma medication scores were noted in the combination group at 24 and 48 wk. Local adverse reactions were fewer in the combination group, and no systemic adverse reactions were reported.

CONCLUSION

Combining omalizumab with SCIT provides quicker asthma control, lowers medication requirements, and enhances lung function with fewer adverse effects, making it a safe and effective treatment for children with bronchial asthma.

Is It Possible to Predict Systemic Adverse Effects in Subcutaneous Allergen Immunotherapy? Single-Center Experience

INTRODUCTION

Subcutaneous immunotherapy (SCIT) is the oldest and an efficient immunotherapy method that has been used for the treatment of allergic diseases. Systemic adverse effects (SAEs) may occur during the SCIT. For this reason, there may be problems in the continuing treatment. In this study, we primarily aimed to determine the frequency of SAEs, the risk factors that may be associated with SAEs, and clinical and laboratory parameters that can predict systemic reactions in the patients who underwent SCIT. Second, we aimed to evaluate the reasons for discontinuing SCIT and the conditions special to Turkey.

METHODS

The files of 295 patients who had received SCIT were evaluated retrospectively.

RESULTS

SCIT was administered against house dust mites (HDM) in almost all patients (n: 291, 98.6%). A total of 14,357 injections were administered to 295 patients included in the study, and 47.8% (n: 141) of the patients discontinued treatment. The most common reason for discontinuing treatment was the supply problem in Turkey for immunotherapy preparations (n: 70, 49.6%). The second reason was that the injection visits were not continued regularly, even though there were no adverse effects related to the treatment (n: 44, 31.2%). SAEs were observed in 16.6% of the patients and 0.66% of the injections. SAEs were more frequent in girls, in asthmatic patients, and in moderate asthmatic patients (p = 0.005, p = 0.016, p = 0.043, respectively). Treatment was terminated in 13 patients (4.4%) due to SAEs. The most common SAE was bronchoconstriction (n: 40, 85.1%). None of our patients developed hypotension or loss of consciousness. Median blood eosinophil count and basophil count and the skin prick test diameter for Dermatophagoides farinae were observed to be significantly higher in the group with SAE (p = 0.024, p = 0.034, p = 0.045, respectively).

CONCLUSION

Although SAE may develop in pediatric patients undergoing HDM-specific SCIT, severe reactions are rare. Girls, asthmatic patients, especially moderate asthmatic patients, and patients with high blood eosinophil and basophil levels should be monitored more carefully for the development of SAE.

Long-term effects of pollen allergoid tyrosine-adsorbed subcutaneous immunotherapy on allergic rhinitis and asthma

BACKGROUND

Allergen immunotherapy (AIT) may have a long-term disease-modifying effect. The aim of this study was to demonstrate the long-term effects of pollen allergoid tyrosine-adsorbed subcutaneous AIT on allergic rhinitis (AR) and asthma (AA) in clinical practice.

METHODS

This retrospective study, funded by an AIT manufacturer, analysed the impact of AIT on AR progression and onset of need for AA medication, using a German database covering ~35% of national prescriptions during 2008-2020. Anonymized prescription data of AR patients aged 5-65 years treated with grass or tree pollen AIT between 2009 and 2013 and followed for at least 2 years after AIT cessation were compared with matched control patients with seasonal AR.

RESULTS

181,496 patients received AIT prescriptions. 5959 fulfilled the inclusion criteria. The median AIT treatment duration was 1092 days and the follow-up duration was 6.4 years. Less patients treated with AIT received prescriptions for symptomatic AR medication in the follow-up versus controls (AIT: OR: 0.37; 95% Confidence Interval (CI) 0.34, 0.40; p < .001, tyrosine-adsorbed AIT: OR: 0.27; 95% CI 0.20, 0.35 p < .001). Less asthmatic patients under AIT received prescriptions for AA medications versus controls (AIT: OR: 0.48; 95% CI 0.41, 0.55; p < .001, tyrosine-adsorbed AIT: OR: 0.48; 95% CI 0.29, 0.79; p = .004). AR and AA medication prescriptions for AIT patients were reduced in the follow-up versus baseline and controls (AIT: AR: 20.0%; 1.5 vs. 0.2 prescriptions; AA: 29.1%; 2.0 vs. 0.6 prescriptions, p < .001; tyrosine-adsorbed AIT: AR: 24.2%, 1.4 vs. 0.2 prescriptions; AA: 35.6%, 2.1 vs. 0.6 prescriptions, p < .001). The probability of AA medication onset in non-asthmatic patients during follow-up was reduced for AIT patients compared to controls (OR: 0.77, 95% CI 0.66, 0.90; p = .001). All endpoints were significant for children/adolescents and adults in stratified analyses.

CONCLUSIONS

We found evidence for long-term effects up to 9.5 years for tyrosine-adsorbed AIT.

The KAAACI Guidelines for Sublingual Immunotherapy

Allergen immunotherapy is regarded as the only disease-modifying treatment option for various allergic conditions, including allergic rhinitis and asthma. Among the routes of administration of allergens, sublingual immunotherapy (SLIT) has gained clinical interest recently, and the prescription of SLIT is increasing among patients with allergies. After 30 years of SLIT use, numerous pieces of evidence supporting its efficacy, safety, and mechanism allows SLIT to be considered as an alternative option to subcutaneous immunotherapy. Based on the progressive development of SLIT, the current guideline from the Korean Academy of Asthma, Allergy, and Clinical Immunology aims to provide an expert opinion by allergy, pediatrics, and otorhinolaryngology specialists with an extensive literature review. This guideline addresses the use of SLIT, including 1) mechanisms of action, 2) appropriate patient selection for SLIT, 3) the currently available SLIT products in Korea, and 4) updated information on its efficacy and safety. This guideline will facilitate a better understanding of practical considerations for SLIT.

Safety of subcutaneous and sublingual immunotherapy with allergoids in children: a real-life pharmacovigilance study

Aims: Allergen-specific immunotherapy uses a sublingual (sublingual immunotherapy [SLIT]) or subcutaneous (subcutaneous immunotherapy [SCIT]) route. This pharmacovigilance study aimed to determine the number and type of adverse drug reactions (ADRs) for SLIT and SCIT using carbamylated monomeric allergoids (CMAs) in children. Materials & methods: This pharmacovigilance study analyzed real-world post-marketing reports collected from a safety database of Lais sublingual tablets and injective Lais-in, containing CMAs for over 10 years. Results & conclusion: From January 2009 to September 2022, 26,107 doses of Lais-in were administered in children; only two nonserious related ADRs (incidence: 0.000077%) were reported. Regarding SLIT, the results showed only 12 spontaneous nonserious ADR reports (incidence: 0.000004%). These data showed the excellent safety profile of both SLIT and SCIT CMAs.

Adverse events in children and adolescents undergoing allergen immunotherapy for respiratory allergies-Report from the Allergen Immunotherapy Adverse Events Registry (ADER), a European Academy of Allergy and Clinical Immunology taskforce

BACKGROUND

Although it has been shown that allergen immunotherapy (AIT) is well-tolerated in children, systematic and prospective surveillance of AIT safety in real life settings is needed.

METHODS

The multinational Allergen Immunotherapy Adverse Events Registry (ADER) was designed to address AIT safety in real life clinical practice. Data on children ≤18 years old with respiratory allergies undergoing AIT were retrieved. Patient- and AIT-related features were collected and analyzed. The characteristics of adverse events (AE) and risk factors were evaluated.

RESULTS

A total of 851 patients, 11.3 ± 3.4 years old, with rhinitis only (47.6%); asthma and rhinitis (44.5%); asthma (7.9%), receiving 998 AIT courses were analyzed. Sublingual immunotherapy (SLIT) accounted for 51% of the courses. In 84.5% of patients only one AIT treatment was prescribed. Pollen was the most frequent sensitizer (57.1%), followed by mites (53.4%), molds (18.2%) and epithelia (16.7%). Local and systemic AEs were reported in 85 patients (9.9%). Most AEs (83.1%) were mild and occurred in <30 min (87%). Respiratory and cutaneous symptoms were more frequent. Only 4 patients (0.47%) had severe AE (none after 6 weeks of maintenance). The risk of AE was higher in patients undergoing SCIT.

CONCLUSIONS

AIT is safe and well tolerated in children and adolescents with respiratory allergies in real-life clinical practice. Though SCIT is more prone to AE compared to SLIT, overall severe reactions are rare and occur during build-up and early maintenance.

Allergen immunotherapy: progress and future outlook

INTRODUCTION

Allergy, the immunological hypersensitivity to innocuous environmental compounds, is a global health problem. The disease triggers, allergens, are mostly proteins contained in various natural sources such as plant pollen, animal dander, dust mites, foods, fungi and insect venoms. Allergies can manifest with a wide range of symptoms in various organs, and be anything from just tedious to life-threatening. A majority of all allergy patients are self-treated with symptom-relieving medicines, while allergen immunotherapy (AIT) is the only causative treatment option.

AREAS COVERED

This review will aim to give an overview of the state-of-the-art allergy management, including the use of new biologics and the application of biomarkers, and a special emphasis and discussion on current research trends in the field of AIT.

EXPERT OPINION

Conventional AIT has proven effective, but the years-long treatment compromises patient compliance. Moreover, AIT is typically not offered in food allergy. Hence, there is a need for new, effective and safe AIT methods. Novel routes of administration (e.g. oral and intralymphatic), hypoallergenic AIT products and more effective adjuvants holds great promise. Most recently, the development of allergen-specific monoclonal antibodies for passive immunotherapy may also allow treatment of patients currently not treated or treatable.

Criteria used by health professionals on the selection of allergen immunotherapy in real clinical practice: Methodology

Background

Allergen immunotherapy (AIT) is today the only etiological therapy for respiratory allergic diseases, including allergic rhinitis, allergic conjunctivitis, and allergic asthma. Even though interest in real-world data has recently increased, publications mainly focus on short-term and long-term efficacy and safety of AIT. Indeed, information is still lacking regarding the "key parameters" or "drivers of prescription" used by doctors to prescribe AIT or by the patients to accept AIT as treatment for their respiratory allergic disease. Examining these factors is therefore the main goal of the CHOICE-Global Survey: "Criteria Used by Health Professionals on the Selection of Allergen Immunotherapy in Real Clinical Practice: An international academic electronic survey".

Methods

We present the methodology of the CHOICE-Global Survey, an academic, prospective, multicenter, observational, transversal, web-based e-survey, conducted in real-life clinical settings designed to collect data from 31 countries representing 9 global different socio-economic and demographic regions. In the present document, we describe the survey, how it was conceived and developed, how data are stored and analyzed, and the different steps that will provide this information to the allergy community.

Conclusions

The CHOICE-Global Survey will be able to provide, from an academic point of view, information on the drivers of prescription of AIT in real-life practice and improve understanding regarding the key parameters considered by doctors and patients for such therapy.

A single center retrospective study of systemic reactions' distribution and risk factors to subcutaneous immunotherapy with dust mite extract in patients with allergic rhinitis and/ or asthma

To analyze various risk factors including causes that may lead to adverse reactions, especially systemic adverse reactions（SRs）, before and after mite allergen subcutaneous immunotherapy (SCIT), so as to provide real-world reference data for further improving the safety of mite allergen SCIT. Methods: The local adverse reactions（LRs）and SRs of 230 patients with allergic rhinitis and/or asthma who received SCIT in Weifang people's hospital were analyzed retrospectively. The data of patient characteristics, drug factors and environmental elements of adverse reactions were collected and statistically analyzed. Results: There were 28 cases (12.2%) of SRs in 230 patients. All the patients received a total of 7515 injections and 37 SRs (0.49%) were observed. 32.4% (12/37) of SRs could identify their external and subjective triggers. SRs patients had higher 2-year SCIT compliance than no-SRs patients (p = 0.026). The prevalence of SRs in SCIT patients with atopic dermatitis or simple allergic asthma are no statistical significance (P = 0.111). Conclusion: the incidence of SRs in this study is within an ideal range. Through professional patient education and pre injection risk factor assessment, Compliance is still well-controlled and guaranteed although SRs occurred.

MicroCrystalline Tyrosine-adsorbed immunotherapy

PURPOSE OF REVIEW

The purpose of this article is to provide an overview of the literature pertaining to the use of MicroCrystalline Tyrosine (MCT) in the immunotherapy with an emphasis on recent developments.

RECENT FINDINGS

In addition to significant effectiveness and safety profiles, additional aspects of interest such as booster immunotherapy concepts, sustained clinical effects, long-term efficacy and disease-modifying effects are being focused on in the recently published studies. The depot adjuvant MCT also shows potential in promising disease-challenge models such as for malaria and melanoma.

SUMMARY

MCT-adsorbed immunotherapy products have been shown to provide convincing overall safety, tolerability and efficacy outcomes, as well in vulnerable groups such as children and asthmatic patients.

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

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

Effectiveness and adverse reactions to subcutaneous immunotherapy in children with allergic rhinitis/asthma

OBJECTIVE

Adverse reactions, which are mostly local and rarely systemic, can be seen during subcutaneous immunotherapy (SCIT). It was not possible to continue SCIT at times due to systemic reactions. The purpose of the present study was to identify the incidence and risk factors associated with adverse reactions during subcutaneous allergen-specific immunotherapy (AIT).

METHODS

A total number of 344 patients under 18 years old with allergic rhinitis and/or asthma who underwent SCIT between 2005 and 2021 were included in the study. Demographic characteristics of the patients, laboratory findings [Total Immunglobulin E(IgE), aeroallergen prick test, inhaler, and allergen specific IgE(sIgE) and eosinophil counts], and adverse events observed during AIT were recorded retrospectively. Descriptive and univariate/multivariate logistic regression analyses were used to identify risk factors for adverse events.

RESULTS

Among 344 patients, 33.4% (n = 115) were female, mean age was 133.1 ± 41.0 months, and 42.2% (n = 145) were >12 years old. One hundred-thirty eight (40.1%) of the patients were mono-sensitized, 47 (13.7%) had asthma, 207 (60.2%) allergic rhinitis, and 90 (26.2%) asthma and allergic rhinitis. Single allergen content was administered to 187 (54.4%) patients (62 mite, 114 grass mix, 11 olea), and multiple allergens to 157 (45.6%) patients (121 pollen mix, 36 other (mite/alternaria)]. A total number of 33.008 injections were administered. 840 adverse reactions (262 (31.1%) at up-dosing phase, 578 (68.8%) at maintenance phase) in 195 (56.7%) patients were observed. Among the adverse reactions, 632 (75.2%) were local, 160 (19%) large local, and 48 (5.7%) (39 at maintenance, 9 at up-dosing) (in 31 patients) were systemic (28 Grade 1, 12 Grade 2, 8 Grade 3). Adrenalin was administered to 8 patients with Grade 3 systemic reaction (8/33008; %0.024). Adverse reactions, especially local ones, were seen more frequently in children under 12 years old (p < 0.001). Patients sensitized with grass pollen (p:0.01) and mite (p:0.004), and those who had received SCIT with pollen mixture had more adverse reactions than the others. More adverse reactions were observed in SCIT containing calcium-phosphate as adjuvant (p: 0.01). Local reactions were risk factors for large local (OR = 3.591, %95 CI:2.064-6.247, p < 0.001) and systemic (OR = 2.190, %95 CI:1.005-4.722 p = 0.046) reactions at univariate analyses. Total nasal symptom scores, Visual Analog Scale and asthma symptom control test decreased after one year of treatment (p < 0.01).

CONCLUSION

SCIT is a safe and effective treatment method in childhood that leads to improvements in all nasal symptoms and asthma after one year of treatment.

Pediatric Anaphylaxis: A 20-Year Retrospective Analysis

BACKGROUND

Anaphylaxis is a steadily increasing global problem defined as an acute hypersensitivity multisystem reaction that is potentially fatal. In the pediatric age, the leading cause is food. In other allergic diseases, intrinsic heterogeneity has been reported in the clinical presentation, severity, and triggers of anaphylaxis. This study analyzes the features and management approach of the anaphylactic reactions in children evaluated at the pediatric clinic in Pavia.

MATERIALS AND METHODS

A retrospective study was conducted on patients with anaphylaxis between 2001 and 2021.

RESULTS

A total of 148 patients with a median age of 5 years were enrolled, and 80% of the patients had other atopic comorbidities that were correlated with the severity of anaphylaxis. The main trigger of anaphylaxis was food. Most reactions involved mucocutaneous, respiratory, and gastrointestinal systems, and occurred at home. Adrenaline was administered only in a minority of cases.

CONCLUSIONS

Considering that anaphylaxis is a potentially life-threatening condition requiring prompt management, the use of adrenaline should be implemented. Our data also suggest the importance of educating and spreading awareness of anaphylactic management within the medical community.

Efficacy and safety of house dust mite sublingual immunotherapy tablets in allergic rhinitis: A systematic review and meta-analysis

Background

House dust mite (HDM) sublingual immunotherapy (SLIT) tablets have been approved for the treatment of patients with allergic rhinitis (AR). However, the meta-analysis on the efficacy of HDM-SLIT tablets for HDM-induced AR patients remained limited.

Methods

Five databases were searched including: PubMed/MEDLINE, EMBASE, Web of Science, the Cochrane Central Register of Controlled Trials, and CINAHL for randomized controlled trials (RCTs) that addressed the efficacy and safetyof HDM-SLIT tablets compared with placebo until January 2022. The primary outcome was a combined symptom and medication score (CSMS) after treatment.

Results

Eight eligible RCTs were identified with a total of 3601 patients treated with HDM-SLIT tablets and 2783 patients who received a placebo. The CSMS was significantly lower in the HDM-SLIT tablet group compared with the placebo (standardized mean difference (SMD) -0.28 [95% CI: -0.32 to -0.23]). There was a significant reduction in rhinitis symptom scores, rhinitis medication scores, total combined conjunctivitis scores, and rhinoconjunctivitis quality of life questionnaire scores. The consistent efficacy compared to the placebo has been exhibited over the different kinds and doses of HDM tablets (6 SQ, 12 SQ, 300 IR, and 500 IR) and age groups (>5 years old, adolescents and adults) with low degrees of variability across the studies. There was no significant difference in proportions of participants who were injected with epinephrine between the treatment- and placebo groups.

Conclusions

HDM-SLIT tablet is an effective treatment in reducing rhinitis symptoms and medication use in AR patients with favorable safety. They also improve quality of life and conjunctivitis symptoms.

Ragweed sublingual immunotherapy (SLIT) tablets in allergic rhinoconjunctivitis: a systematic review and meta-analysis

PURPOSE

Ragweed allergen causes Allergic rhinoconjunctivitis and sublingual immunotherapy is one of the treatment modalities to desensitize allergic individuals. This systematic review assesses the effectiveness and safety of sublingual immunotherapy for allergic rhinoconjunctivitis caused due to Ragweed.

METHODS

The databases search was done through December 2020. English-language randomized controlled trials were included if they compared sublingual immunotherapy with placebo, pharmacotherapy, or other sublingual immunotherapy regimens, and reported clinical outcomes. The strength of the evidence for each comparison and outcome was graded based on the risk of bias, consistency, magnitude of effect, and the directness of the evidence.

RESULTS

The searches performed according to the protocol identified 134 abstracts of which 67 were duplicates. A total of 37 full papers were therefore reviewed of which 5 were included for the final study. Participants' ages ranged from 4 to 58 years. The risk of bias was low in most studies. The review suggests that sublingual immunotherapy improves rhinoconjunctivitis symptoms, with 4 of 4 studies reporting efficacy showed improvement in the symptom score of SLIT groups compared to placebo. Local reactions were frequent, but anaphylaxis was not reported in any of the studies. Serious adverse events were very few in all the studies.

CONCLUSIONS

The overall evidence showed the effectiveness of sublingual immunotherapy for the treatment of allergic rhinoconjunctivitis with or without asthma, but high-quality studies are still needed to answer questions regarding optimal dosing strategies.

Anaphylaxis in children and adolescents: The Portuguese Anaphylaxis Registry

BACKGROUND

Anaphylaxis is increasing at pediatric age; however, its characterization is hampered by underdiagnosis and underreporting. The aim of this study was to identify the causes of anaphylaxis in children and adolescents in Portugal, thus contributing to a better knowledge of its etiology, clinical manifestations, and management.

METHODS

During a 10-year period, a nationwide notification system for anaphylaxis was implemented, with voluntary reporting by allergists. Data on 533 patients under 18 years of age with anaphylaxis were included.

RESULTS

Mean age was 8.5 ± 4.9 years, 61% were male; 45% had asthma. Mean age at the first anaphylaxis episode was 5.3 ± 4.7 years (ranging from 1 month to 17 years of age), 63% at pre-school age. Most reactions occurred at home (57%). Food-induced anaphylaxis was the leading cause (77%). The main culprit foods were cow's milk (32%), tree nuts (16%), shellfish (13%), egg (12%), fresh fruits (11%), fish (8%), and peanut (8%). Other causes included drugs (11%), insect sting (5%), cold-induced anaphylaxis (4%), exercise-induced anaphylaxis (2%), latex (1%), and idiopathic anaphylaxis (1%). Most patients (83%) were admitted to the emergency department; only 46% received adrenaline treatment. Recurrence of anaphylaxis occurred in 41% of the patients (3 or more episodes in 21%). An adrenaline autoinjector was used in 9% of the patients.

CONCLUSIONS

In the Portuguese pediatric population, food is the leading cause of anaphylaxis. Undertreatment with adrenaline and high recurrence of anaphylaxis highlight the need to improve both the diagnosis and the therapeutic management of this life-threatening entity.

Real-life studies in allergen immunotherapy

PURPOSE OF REVIEW

Real-life (or real-world) studies can provide information that cannot be derived from randomized controlled trials. This approach is currently becoming of relevance for many treatments. In recent years, the real-life method has been applied also to allergen immunotherapy, providing new insights on it. We reviewed herein the available literature on the argument.

RECENT FINDINGS

Several prospective and retrospective studies on allergen immunotherapy in the real-world setting have been published, mostly in the last 5 years. Most of them focused on adverse events, compliance, and the long term/preventive effects, and evidenced an overall favorable profile for different products and different allergens.

SUMMARY

Real life study provided novel information and evidenced those aspects of immunotherapy that worth a more detailed approach, without the strict limitations usually imposed by controlled randomized trials.

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.

Antihistamine premedication improves safety and efficacy of allergen immunotherapy

BACKGROUND

Allergen immunotherapy (AIT)-associated adverse events are a major concern for safety and efficacy of AIT. Presently, there is no consensus to whether antihistamine premedication could improve such conditions.

OBJECTIVE

To identify the superiority of antihistamine pretreatment in AIT.

METHODS

A comprehensive literature search for randomized controlled trials reporting the effects of antihistamine premedication on safety and efficacy of AIT was performed in MEDLINE, Embase, and Cochrane Library databases. Safety was evaluated according to the number of patients reporting systemic adverse reactions (SARs, the primary outcome) and efficacy according to the number of patients achieving target maintenance dose (TMD) and sustained unresponsiveness to allergen.

RESULTS

A total of 11 randomized controlled trials (including 609 patients) satisfied the inclusion criteria for the meta-analysis. All premedication protocols were temporary. Pooled analysis revealed that compared with control patients, significantly fewer antihistamine-pretreated patients reported total and moderate-to-severe SARs (odds ratio [OR], 0.36; 95% confidence interval [CI], 0.23-0.56; P < .05 and OR, 0.20; 95% CI, 0.06-0.74; P < .05, respectively) and total and moderate-to-severe SAR episodes (OR, 0.42; 95% CI, 0.34-0.53; P < .05 and OR, 0.09; 95% CI, 0.01-0.50; P < .05, respectively). Similarly, antihistamine pretreatment significantly increased the number of patients achieving TMD (OR, 2.94; 95% CI, 1.72-5.03; P < .05), but not sustained unresponsiveness (OR, 1.65; 95% CI, 0.77-3.54; P = 0.2), compared with the control group. Subgroup analysis according to different allergens and dose-escalating approaches also displayed superiority of antihistamine pretreatment than control.

CONCLUSION

Antihistamine premedication can markedly improve safety and efficacy of AIT by reducing frequency and severity of SAR and increasing TMD.

Current and emerging pharmacotherapy for pediatric allergic rhinitis

INTRODUCTION

Allergic rhinitis (AR) is a global health problem in adults as well as the younger population, continuously increasing and posing a significant problem for patients, health care systems and economies. For the younger population, some aspects differ from treatment of adults, namely, prevention, compliance and adherence.

AREAS COVERED

This narrative review summarizes all the pharmacotherapeutic options with special focus on the pediatric population. Moreover, it elucidates prevention strategies as well as future developments of AR treatment. Currently, symptomatic therapy in the form of steroids and antihistamines is applied topically and systemically where steroids need to be administered with caution and for a very short term. The only disease-modifying and causal treatment is allergen immunotherapy administered sublingually and subcutaneously. Future and current novel therapeutic options are human monoclonal antibodies.

EXPERT OPINION

The greatest potential for future developments currently lie in allergen immunotherapy and here in different routes of administration and modification of (recombinant) allergens as well as immune-modulating adjuvants and nanoparticles. Secondly, monoclonal antibodies are promising molecules blocking and/or interfering with up- and downstream immune mechanisms. Another important aspect lies in prevention of allergic sensitization and disease progression through both AIT and biologics which is particularly true for the pediatric population.

Allergens and Adjuvants in Allergen Immunotherapy for Immune Activation, Tolerance, and Resilience

Allergen immunotherapy (AIT) is the only setting in which a vaccine is applied in patients allergic exactly to the active principle in the vaccine. Therefore, AIT products need to be not only effective but also safe. In Europe, for subcutaneous AIT, this has been achieved by the allergoid strategy in which IgE epitopes are destroyed or masked. In addition, adjuvants physically precipitate the allergen at the injection site to prevent too rapid systemic distribution. The choice of adjuvant critically shapes the efficacy and type of immune response to the injected allergen. In contrast to T_H2-promoting adjuvants, others clearly counteract allergy. Marketed products in Europe are formulated with aluminum hydroxide (alum) (66.7%), microcrystalline tyrosine (16.7%), calcium phosphate (11.1%), or the T_H1 adjuvant monophosphoryl lipid A (5.6%). In contrast to the European practice, in the United States mostly nonadjuvanted extracts and no allergoids are used for subcutaneous AIT, highlighting not only a regulatory but maybe a "historic preference." Sublingual AIT in the form of drops or tablets is currently applied worldwide without adjuvants, usually with higher safety but lower patient adherence than subcutaneous AIT. This article will discuss how AIT and adjuvants modulate the immune response in the treated patient toward immune activation, modulation, or-with new developments in the pipeline-immune resilience.

Preventive Effect of Allergen Immunotherapy on Asthma and New Sensitizations

Allergen immunotherapy (AIT) is a disease-modifying treatment for some IgE-mediated allergic diseases with the potential to have important preventive effects. Children with allergic rhinitis have a high risk of developing asthma, and treating allergic rhinitis with AIT may interfere with disease progression and prevent onset of asthma. Although the evidence is limited due to relatively few and heterogeneous studies, data nevertheless suggest that AIT has a preventive effect on development of asthma especially in children with rhinitis due to grass pollen allergy. AIT may also affect the development of new sensitizations. Both the degree of sensitization and the specific sensitization pattern may influence future disease severity and development of comorbidities. Hitherto, the indication for AIT for prevention of development of asthma in grass/birch pollen allergic children has been the same as for treatment of allergic rhinitis. Probably, AIT should be applied in the early stage of the allergic disease to have the greatest preventive effect on disease progression. Consequently, in the future, the potential preventive effects should influence the timing of initiating AIT. The window of opportunity to prevent asthma may primarily exist in young children with mild symptoms and a low degree of sensitization.

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.

The safety of sublingual immunotherapy, can the rare systemic reactions be prevented?

Introduction: The safety of subcutaneous immunotherapy (SCIT), and particularly the dramatic issue of fatal reactions, has been an obstacle that limited the implementation of a therapy with unique characteristics of action on the causes of allergy. The introduction of sublingual immunotherapy (SLIT) was aimed at solving safety problems while maintaining clinical efficacy.Areas covered: For more than 20 years, SLIT has been based on allergen extracts in drops at low average doses. As evidenced by meta-analyses, the typical adverse events (AE) have consisted of local reactions in the mouth and throat. Unlike the injection route, no correlation was observed between the administered dose and AEs. The development of SLIT products in tablets, based on higher doses than drops, has somewhat changed the concept of SLIT safety. Although large trials, performed to obtain regulatory agency approval, have shown overall high safety, rare anaphylactic reactions have been described.Expert opinion: SLIT is globally safe, and no fatal reactions have ever been reported, but with currently available high biological potency products it is necessary to follow prudential rules, such as the administration of the first dose under medical supervision and the thorough education of patients to avoid taking of higher doses than recommended.

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.

Systemic and large local reactions during subcutaneous grass pollen immunotherapy in children

BACKGROUND

Subcutaneous immunotherapy (SCIT) is the allergen-specific curative treatment of allergic rhinitis. Adverse effects, most of which are local, can be observed during the immunotherapy. These adverse effects have been reported more frequently during the pollen season. The purpose of this study was to estimate the rate of local, large local, and systemic reactions during the treatment, to determine the relationship between adverse reactions and the season in which these reactions occur, as well as the risk factors for adverse reactions during the grass pollen-specific SCIT treatment in children.

METHODS

We retrospectively collected and analyzed the data of 261 children who administered grass pollen SCIT between 2008 and 2018.

RESULTS

A total of 261 children (177, 67.8% male), who received grass pollen SCIT, with a mean (±SD) age of 12.0 ± 3.0 years at the initiation of SCIT were enrolled to the study. The number of the patients who experienced local and large local reactions was 109 and 30, respectively. In addition, the number of the patients with systemic reactions was 35. After the 12 284 injections, local reactions occurred in 357 (2.9%), and this was followed by systemic reaction as 55 (0.4%) and large local reactions as 40 (0.3%). Frequency of local (P < .001) and systemic reactions (P = .003) was higher during grass pollen season than out of the grass pollen season. In multivariate analysis, initiation of SCIT during the grass pollen season [OR:7.351, 95%CI:1.532-35.279, P = .013] and experiencing local reactions [OR:4.214, 95%CI:2.159-8.224, P < .001] were independent predictors for the development of large local and systemic reactions.

CONCLUSION

SCIT, in which only mild-to-moderate systemic reactions occurred, is safe for the treatment of allergic rhinitis in children. Our study revealed that previous local reactions and initiation of immunotherapy during the grass pollen season were the predictors for large local and systemic reactions during SCIT in children.

Allergen Immunotherapy in Pediatric Asthma: A Pragmatic Point of View

To date, the only disease-modifying treatment strategy for allergic rhinitis and asthma is allergen immunotherapy (AIT). There is evidence that AIT improves allergic rhinitis and asthma, such as reducing symptom severity and medication use and improving of quality of life, with a long-lasting effect after the end of the course. The recent clinical trials evidenced AIT effectiveness and safety in allergic asthma. Consequently, the current version of the GINA (Global Initiative for Asthma) guidelines recommend AIT as an add-on therapy for asthma. There is also evidence that AIT may exert preventive activity on the possible progression from allergic rhinitis to asthma in children and the onset of new sensitizations. The present review provides a pragmatic summary of the clinical indications of AIT in pediatric asthma, including the immunological mechanisms, the predictive biomarkers, and the safety issues in clinical practice.

Allergen immunotherapy for respiratory allergy: to what extent can the risk of systemic reactions be reduced?

INTRODUCTION

Allergen immunotherapy is an effective treatment for respiratory allergy, but the administration to patients of extracts of the causative allergen may elicit systemic reactions, which include, particularly with subcutaneous immunotherapy (SCIT), anaphylaxis. In the past, the occurrence (tough rare) of fatal reactions has represented a serious problem that has limited the prescription of SCIT.

AREAS COVERED

The authors analyzed in this review the safety data of SCIT, especially concerning the years following the identification of uncontrolled asthma at the moment of allergen injection as the major risk of life-threatening reactions and fatalities. The safety of SLIT, which is far better than SCIT, was analyzed and its specific risk factors for systemic reactions were highlighted.

EXPERT OPINION

Presently, the safety profile of SCIT and SLIT is satisfactory, provided the treatment is administered by physicians experienced in this treatment, who are aware of the known risk factors for severe reactions and who implement all measures to avoid them. For SLIT, which is self-administered by the patient, receiving the first dose under medical control is recommended.

Subcutaneous Immunotherapy Safety: Incidence per Surveys and Risk Factors

Subcutaneous immunotherapy (SCIT) is effective for allergic rhinitis and conjunctivitis, asthma, and insect venom hypersensitivity. The risk of severe allergic reactions induced by SCIT remains low, and mild systemic reactions have recently shown a tendency to decline. However, near-fatal and fatal anaphylactic reactions may occur. Clinicians administering allergen-specific immunotherapy should receive specialized training and be aware of risk factors and preventive measures to avoid severe allergic reactions induced by SCIT.

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.

Halting the March: Primary Prevention of Atopic Dermatitis and Food Allergies

Atopic dermatitis (AD) is one of the most common inflammatory skin conditions, affecting 15% to 30% of children and 2% to 10% of adults. Population-based studies suggest that having AD is associated with subsequent development of other atopic diseases, in what is known as the "atopic march." We will provide an overview of studies that investigate primary prevention strategies for the first 2 diseases in the march, namely, AD and food allergies (FA). These strategies include emollients, breastfeeding, microbial exposures, probiotics, vitamin D and UV light, water hardness, and immunotherapy. Some studies, including randomized controlled trials on emollients and microbial supplementation, have found encouraging results; however, the evidence remains limited and contradictory. With regard to breastfeeding, microbial and lifestyle exposures, vitamin D and UV light, water hardness, and immunotherapy, the lack of randomized controlled trials makes it difficult to draw definitive conclusions. Current American Academy of Pediatrics guidelines support the idea that breastfeeding for 3 to 4 months can decrease AD incidence in children less than 2 years old. Recommendations regarding a direct relationship between breastfeeding on FA, however, cannot be made because of insufficient data. Regarding microbial supplementation, most guidelines do not recommend probiotics or prebiotics for the purpose of preventing allergic diseases because of limited evidence. Before definitive conclusions can be made regarding these interventions, more well-designed, longitudinal, and randomized controlled trials, particularly in at-risk populations, are required.

Safety of Timothy Grass Sublingual Immunotherapy Tablet in Children: Pooled Analyses of Clinical Trials

BACKGROUND

Timothy grass sublingual immunotherapy (SLIT) tablets are indicated for children with allergic rhinitis with or without conjunctivitis.

OBJECTIVE

To use pooled analyses to assess the short- and long-term tolerability and safety of timothy grass SLIT-tablet in children.

METHODS

Data from 9 double-blinded, randomized European or North American trials that included children with allergic rhinitis with or without conjunctivitis treated up to 3 years with once-daily timothy grass SLIT-tablet or placebo were pooled.

RESULTS

In all, 1818 (timothy grass SLIT-tablet, n = 923; placebo, n = 895) subjects were included in the analysis. The frequency of treatment-emergent adverse events (AEs) was 86% in the SLIT-tablet group and 83% in the placebo group, and the frequency of treatment-related AEs (TRAEs) was 59% and 23%, respectively. Most (98%) TRAEs were mild to moderate in severity. The 2 most common TRAEs with SLIT-tablet were oral pruritus (33%) and throat irritation (19%), which had a median onset of 1 day and recurrence of 14.5 and 5 days, respectively. In all, 8% of subjects in the SLIT-tablet group and 2% in the placebo group discontinued because of AEs. There were 7 serious AEs assessed as related to SLIT-tablet, 1 systemic allergic reaction (severe with a drop in blood pressure), 3 epinephrine administrations, no eosinophilic esophagitis events, and no serious airway obstructions. The safety profile was similar in subjects across geographic regions and with and without asthma.

CONCLUSIONS

Pooled data indicate that short- and long-term timothy grass SLIT-tablet is well tolerated in children, regardless of geographic region. AEs were generally local, mild, and transient allergic reactions.

Comparison of adverse events between cluster and conventional immunotherapy for allergic rhinitis patients with or without asthma: A systematic review and meta-analysis

BACKGROUND

Cluster schedule of allergen-specific immunotherapy (AIT) is a cost-effective choice for allergic rhinitis (AR) patients, but its safety has been questioned due to the greater dosages required at each treatment compared with conventional immunotherapy. It remains a question that whether cluster schedule leads to a higher risk of side effects.

OBJECTIVE

This study was designed to update the evidence and investigate whether cluster schedule leads to a higher risk of local adverse reactions (LARs) and systemic adverse reactions (SARs) than cluster schedule does.

METHODS

We searched the Cochrane Central Register of Controlled Trials, EMBASE and Medline thoroughly and included studies comparing cluster and conventional schedules. A meta-analysis of 5 outcomes related to adverse events was performed after bias and heterogeneity assessments. And as a result of language limitations, we considered only articles in Chinese and English.

RESULTS

5 observational studies and 6 interventional studies were included in the meta-analysis. There were no differences between cluster and conventional schedules when analyzing SARs by the number of patients, delayed SARs, grade 2 SARs and LARs. Analyses of SARs by injection, grade 1 SARs and LARs by injection in observational studies showed that cluster schedule had a lower risk of adverse events than did conventional schedule.

CONCLUSION

Our data suggest that cluster schedule is as safe as or even safer than conventional schedule for AR patients with or without asthma (AS).

Persistence of the clinical effect of grass allergen peptide immunotherapy after the second and third grass pollen seasons

BACKGROUND

Grass allergen peptides are in development for the treatment of grass pollen-induced allergic rhinoconjunctivitis. A previous randomized, placebo-controlled study demonstrated that grass allergen peptides significantly improved total rhinoconjunctivitis symptom scores (TRSSs) after posttreatment challenge (PTC) to rye grass in an environmental exposure unit after 1 intervening grass pollen season (GPS1).

OBJECTIVE

We sought to evaluate the efficacy/safety of 4 dosing regimens of grass allergen peptides after a second (GPS2) and third (GPS3) intervening GPS in the environmental exposure unit.

METHODS

Eligible subjects who were randomized in the parent study (GPS1) during the first year of recruitment were invited to participate in GPS2 and GPS3, which took place 1 and 2 years after treatment cessation, respectively. Participants were not treated further, and both participants and study personnel remained blinded. The primary efficacy end point was the change in mean TRSS (reported every 30 minutes) from GPS1 baseline to the follow-up PTC calculated across all time points over days 2 to 4 for GPS2 and across hours 1 to 3 over days 2 to 4 for GPS3. Secondary efficacy end points and safety were also assessed.

RESULTS

One hundred twenty-two and 85 participants were enrolled in GPS2 and GPS3, respectively. A numerically greater, but not statistically significant improvement from baseline in mean TRSS at PTC was observed in the group receiving one 6-nmol intradermal injection every 2 weeks for 14 weeks group compared with the placebo at GPS2 (-6.0 vs -3.6, P = .0535) and GPS3 (-6.2 vs -3.6, P = .1128). Similar findings were observed for the group receiving one 6-nmol intradermal injection every 2 weeks for 14 weeks at GPS3 (-6.4 vs -3.6, P = .0759). No adverse safety signals were detected.

CONCLUSION

Treatment with grass allergen peptides led to an improvement in allergic rhinoconjunctivitis symptoms after 3 intervening GPSs, corresponding to up to 2 years off treatment.

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).

Does evidence support the use of cat allergen immunotherapy?

PURPOSE OF REVIEW

Cat allergy can manifest as allergic rhinitis, conjunctivitis and/or asthma. With widespread cat ownership and exposure, cat allergy has emerged as a major cause of morbidity. Cat allergen immunotherapy is a potential disease modifying treatment for patients with cat allergy. We examine evidence on the effectiveness, cost-effectiveness and safety of cat allergen immunotherapy and consider the clinical contexts in which it should be prescribed.

RECENT FINDINGS

The European Association of Allergy and Clinical Immunology systematic reviews on allergic rhinitis and asthma along with the accompanying guidelines on allergic rhinitis were used as primary sources of evidence. Subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) are most common routes of administration for allergen immunotherapy (AIT). A limited number of high-quality studies related to cat dander have shown mixed results in improvements in ocular and nasal symptoms, asthma symptoms, peak expiratory flow rate and medication use scores with subcutaneous immunotherapy. Two studies examining cat dander and cat-related allergy response with sublingual immunotherapy have shown mixed results in terms of symptomatic response. One randomized trial examining intralymphatic immunotherapy has shown a positive symptom response and a favourable safety profile. Although studies have reported mixed results regarding safety of SCIT, adverse events have been reported more commonly with SCIT than SLIT.

SUMMARY

There is a limited body of high-quality evidence on the effectiveness and safety of cat AIT and no high-quality data on its cost-effectiveness. The available evidence on effectiveness is mixed based on studying a limited array of immunological, physiological and patient-reported outcome measures. Based on this evidence and extrapolating on the wider evidence base in AIT, it is likely that some patients may benefit from this modality of treatment, particularly those with moderate-to-severe disease who are inadequately controlled on allergen avoidance measures and pharmacotherapy and those who are monosensitized to Felix Domesticus 1. Further evidence is, however, required from larger trials before more definitive advice can be offered.

Shortened up-dosing with sublingual immunotherapy drops containing tree allergens is well tolerated and elicits dose-dependent clinical effects during the first pollen season

Background

This study compared a rapid home-based up-dosing schedule for sublingual immunotherapy (SLIT) drops containing tree pollen allergens with two previously established schedules. Furthermore, the clinical effect of the SLIT was investigated with respect to patients’ first pollen season under treatment.

Methods

In this open-label, prospective, patient-preference, non-interventional study, local and systemic reactions were compared between three up-dosing groups using a SLIT formulation containing birch, alder, and hazel pollen extracts (ORALVAC^® Compact Bäume). Clinical improvement after patients’ first season under treatment was analysed using symptom scores, ARIA classification, symptom control, and the use of symptomatic medication and was compared with data from the previous, pre-treatment pollen season. As the real-life study design allowed no placebo group, the late-treated patients (co-seasonal) served as a control, and crowd-sourced symptom data from persons with hay fever were used from a free web-based online diary.

Results

In 33 study centres in Germany and Austria, 164 patients were included. The treatment was well tolerated, without difference between the groups during the up-dosing phase. At the end of the assessment, 96.1% rated the tolerability of the treatment as good or very good. Local reactions were mostly mild in severity and no serious adverse events occurred. Symptom scores decreased from the 2016 pollen season to the 2017 pollen season. As for the ARIA classification, 79.0% of patients had persistent, moderate-to-severe rhinitis before treatment, but only 18.6% had the same classification after treatment. In all, 62.4% of patients achieved symptom control, and 34.3% of patients required no symptomatic medication after treatment. The rhinoconjunctivitis score was 34.4% lower for pre-seasonal treatment initiation than for the control group. Crowd-sourced symptom load indices showed that the 2016 season caused slightly more symptoms; however, it is assumed that this difference of 0.3–0.5 (score range 0–10) was of less clinical relevance.

Conclusion

The treatment administered using the rapid home-based up-dosing schedule was safe and well tolerated. Symptom relief and reduction in medication use were observed during the first pollen season with SLIT.

Trial registration number

NCT03097432 (clinicaltrials.gov).

Comparison of International Systemic Adverse Reactions Due to Allergen Immunotherapy

BACKGROUND

Several classifications of systemic adverse reactions (SARs) during allergen immunotherapy have been proposed, but the comparison of their usefulness in daily clinical practice is lacking.

OBJECTIVE

The present post hoc analysis was aimed at investigating the practicality of the most relevant international classifications proposed by the European Academy of Allergology and Clinical Immunology (EAACI), the American Academy of Asthma, Allergology and Clinical Immunology/American College of Allergy, Asthma and Immunology (AAAACI/ACAAI), and the World Allergy Organization (WAO) using data provided by the longitudinal European Survey on Adverse Systemic Reactions in Allergen Immunotherapy (EASSI) based on daily clinical practice in 3 countries in Europe.

METHODS

One hundred nine SARs over 4363 allergen immunotherapy courses were classified as mild (n = 78 [71.5%]), moderate (n = 27 [24.8%]), and severe (n = 4 [3.7%]) by EASSI-doctors, which served as a criterion standard. Every SAR was further classified according to the following grading systems: EAACI 2006 Grading System (EAACI2006), WAO 2010 Grading System (WAO2010), WAO 2017 Grading System (WAO2017), and AAAAI/ACAAI Grading System. All SAR rankings were also cross-compared among each other (Kendall correlation coefficient Tau-b). In general, a low epinephrine use was identified, severe reactions occurred within 15 minutes, and milder reactions were skin only.

RESULTS

The analysis indicated disparities in mild and moderate SARs in the different grading systems. The correlation between EASSI-severity and EAACI2006, WAO2010, WAO2017, and AAAAI/ACAAI Grading System was 0.639, 0.502, 0.315, and 0.663, respectively (P < .001 in all cases). However, correlation of severe reactions was good. The best correlation with the onset of the reaction and the number of System Organ Class involved were detected in WAO grading systems.

CONCLUSIONS

Despite having a lower correlation than EAACI and AAAAI/ACAAI, the WAO grading appears to provide a moderate correlation among these classifications. The analysis might help to inform clinicians and investigators on selecting the most appropriate classification.

Highlights and recent developments in airway diseases in EAACI journals (2017)

The European Academy of Allergy and Clinical Immunology (EAACI) owns three journals: Allergy, Pediatric Allergy and Immunology and Clinical and Translational Allergy. One of the major goals of EAACI is to support health promotion in which prevention of allergy and asthma plays a critical role and to disseminate the knowledge of allergy to all stakeholders including the EAACI junior members. There was substantial progress in 2017 in the identification of basic mechanisms of allergic and respiratory disease and the translation of these mechanisms into clinics. Better understanding of molecular and cellular mechanisms, efforts for the development of biomarkers for disease prediction, novel prevention and intervention studies, elucidation of mechanisms of multimorbidies, entrance of new drugs in the clinics as well as recently completed phase three clinical studies and publication of a large number of allergen immunotherapy studies and metaanalyses have been the highlights of the last year.

Allergen immunotherapy in people, dogs, cats and horses - differences, similarities and research needs

In human patients with seasonal allergic rhinoconjunctivitis sensitized to grass pollen, the first successful allergen immunotherapy (AIT) was reported in 1911. Today, immunotherapy is an accepted treatment for allergic asthma, allergic rhinitis and hypersensitivities to insect venom. AIT is also used for atopic dermatitis and recently for food allergy. Subcutaneous, epicutaneous, intralymphatic, oral and sublingual protocols of AIT exist. In animals, most data are available in dogs where subcutaneous AIT is an accepted treatment for atopic dermatitis. Initiating a regulatory response and a production of "blocking" IgG antibodies with AIT are similar mechanisms in human beings and dogs with allergic diseases. Although subcutaneous immunotherapy is used for atopic dermatitis in cats, data for its efficacy are sparse. There is some evidence for successful treatment of feline asthma with AIT. In horses, most studies evaluate the effect of AIT on insect hypersensitivity with conflicting results although promising pilot studies have demonstrated the prophylaxis of insect hypersensitivity with recombinant antigens of biting midges (Culicoides spp.). Optimizing AIT using allergoids, peptide immunotherapy, recombinant allergens and new adjuvants with the different administration types of allergen extracts will further improve compliance and efficacy of this proven treatment modality.

Immunotherapy and Asthma in Children

Allergen immunotherapy (AIT) is still the only disease-modifying treatment strategy for IgE-mediated allergic diseases, with consolidated evidence both in adults and children. AIT is effective in determining clinical improvement of allergic rhinitis and asthma, such as reduced symptoms, medication use, and improvement of quality of life, with a long-lasting effect after cessation of treatment. Results from recent clinical studies have implemented the evidence of effectiveness and safety of allergen immunotherapy for the treatment of allergic asthma, so that the current asthma guidelines now recommend sublingual immunotherapy as an add-on therapy for asthma in adults and adolescents with house dust mite allergy, allergic rhinitis, and exacerbations despite low-to-moderate dose ICS, with forced expiratory volume in 1 second more than 70% predicted. AIT may also reduce the risk of progression from allergic rhinitis to asthma in children and prevent the onset of new sensitizations, thus representing a potentially preventive method of treatment. The aim of this review is to present an updated overview of the clinical indications of AIT, with particular reference to pediatric asthma, of the mechanisms of clinical and immunological tolerance to allergens, and of the potential biomarkers predicting clinical response.