Sublingual allergen immunotherapy: mode of action and its relationship with the safety profile

Real-world assessment of anaphylaxis and eosinophilic esophagitis with 12 SQ house dust mite SLIT-tablet sublingual immunotherapy

Background

Sublingual immunotherapy (SLIT) with 12 SQ house dust mile SLIT-tablet (HDM SLIT-tablet) for dust mite-induced perennial allergic rhinitis is reported as effective and safe. Although serious allergic reactions (SARs) and eosinophilic esophagitis (EoE) have infrequently occurred under trial conditions, the safety of HDM SLIT-tablet challenge under real-world conditions is unknown.

Objective

Our aim was to estimate the incidence of SARs and EoE due to HDM SLIT-tablet challenge.

Methods

Through use of administrative data from Kaiser Permanente Southern California, this prospective observational study identified patients newly administered HDM SLIT-tablet with follow-up until SLIT discontinuation or end of study. Suspected cases of SARs and EoE were detected by using International Classification of Diseases, 10th Revision, diagnosis and Current Procedural Terminology procedure codes and medication dispensing records. A 3-member clinical review committee of allergists adjudicated suspected reactions. The incidence rate of confirmed SARs and EoE per 1000 person years of exposure were determined.

Results

A total of 521 patients (93.9% adult and 6.1% pediatric) were exposed to HDM SLIT-tablet challenge from January 2018 through May 2023, for 440.4 person years of exposure. The patients' average age (SD) was 39.3 (14.1) years, 58.7% were female, 44.3% were non-Hispanic White, 40.3% had asthma, and 15.0% had gastroesophageal reflux disease. A SAR occurred in 1 adult patient, and during initial HDM SLIT-tablet challenge, SARs occurred in 2 pediatric adolescents, for an overall incidence of 6.8 SARs per 1000 patient years (95% CI = 2.2-21.1). EoE occurred in 1 adult patient, for an overall incidence of 2.3 cases of EoE per 1000 patient years (95% CI = 0.3-16.1).

Conclusions

This real-world study demonstrated that SARs and EoE were infrequent events with HDM SLIT-tablet use, supporting the safety of HDM SLIT-tablets and need for physician supervision with initial challenge.

Rhinitis Disease Burden and the Impact of Social Determinants of Health

Social determinants of health (SDHs) have a substantial impact on patient care and outcomes globally, both in low- to middle-income countries and in high-income countries. In the clinic, lack of availability of diagnostic tools, inequities in access to care, and challenges obtaining and adhering to prescribed treatment plans may further compound these issues. This article addresses a case of rhinitis in the context of SDHs and inequities in care that may affect various communities and populations around the world. SDHs may include various aspects of one's financial means, education, access to medical care, environment and living situation, and community factors, each of which could play a role in the rhinitis disease manifestations, diagnosis, and management. Allergic and nonallergic rhinitis are considered from this perspective. Rhinitis epidemiology, disease burden, and risk factors are broadly addressed. Patient evaluation, diagnostic tests, and management options are also reviewed, and issues related to SDHs are noted. Finally, inequities in care, knowledge gaps, and unmet needs are highlighted. It is critical to consider SDHs and care inequities when evaluating and treating patients for rhinitis and other allergic conditions.

Combination of omalizumab with allergen immunotherapy versus immunotherapy alone for allergic diseases: A meta-analysis of randomized controlled trials

BACKGROUND

Allergen immunotherapy (AIT)-associated adverse events (AEs) limit its usage in the management of allergic diseases. The monoclonal anti-IgE antibody (omalizumab) and AIT have complementary actions. However, no consensus has been reached on whether their combination could exert superior efficacy and safety.

OBJECTIVE

To evaluate whether the combination of AIT with omalizumab is superior to AIT alone in treating allergic diseases.

METHODS

The MEDLINE/PubMed, Embase, Scopus and Cochrane Library databases were searched to identify randomized control trials (RCTs) reporting the outcomes of omalizumab combined with AIT (omalizumab + AIT) versus AIT alone. A random-effect model was established to estimate outcomes with a 95% confidence interval (CI).

RESULTS

A total of 11 eligible RCTs (involving 901 patients) were screened out for the meta-analysis. According to a pooled analysis, omalizumab + AIT significantly increased the number of patients achieving the target maintenance dose (TMD) and sustained unresponsiveness (SU) to allergens (odds ratio [OR] = 2.43; 95% CI: 1.33-4.44; p = 0.004; I2 = 35%, and OR = 6.77; 95% CI: 2.10-21.80; p = 0.001; I2 = 36%, respectively). Similarly, individuals receiving the combination therapy reported significantly fewer episodes of severe systemic AEs than AIT alone (OR = 0.32; 95% CI: 0.18-0.59; p = 0.0003; I2 = 0%). Meanwhile, the improvements in symptom severity score (mean difference [MD] = -0.26), rescue medication daily means score (MD = -0.14), and number of patients consuming epinephrine in AIT (OR = 0.20) were all more evident than those in AIT alone.

CONCLUSION

Omalizumab + AIT can significantly enhance the efficacy and safety of AIT by increasing TMD and SU to allergens, while decreasing severe systemic AEs.

Tolerability of sublingual versus vestibular allergy immunotherapy tablet administration: A randomized pilot study

BACKGROUND

Local application site reactions are common with sublingual allergy immunotherapy (AIT)-tablets for the treatment of allergic rhinitis/conjunctivitis (AR/C) and occasionally lead to treatment discontinuation. Because of the lower mast cell density in the vestibular mucosa than the sublingual area, vestibular AIT-tablet administration may result in fewer adverse events (AEs). This pilot study evaluated the tolerability of the vestibular administration route of AIT-tablets compared with the sublingual route in adult subjects with AR/C.

METHODS

Adults (n = 164) aged 18-65 years with AR/C treated with daily birch pollen, grass pollen, ragweed pollen or house dust mite AIT in tablet form were randomized 1:1 to vestibular or sublingual administration for 28 days, followed by 28 days of sublingual administration only. The primary endpoint was the severity (mild, moderate, severe) of local treatment-related adverse events (TRAEs) during the first 28 days of treatment.

RESULTS

During the first 28 days, the percentage of subjects in the vestibular and sublingual groups reporting mild TRAEs were 55.6% versus 50.6%, respectively; moderate TRAEs were 27.2% versus 30.1%; and severe TRAEs were 12.3% versus 6.0% (p = .16). In the vestibular group, 95.1% of the subjects experienced at least one TRAE during the first period versus 81.9% in the sublingual group (p = .01) and discontinuation rates due to AEs were higher (12.3% vs. 3.6%).

CONCLUSION

The frequencies of subjects experiencing severe TRAEs, at least one TRAE, and discontinuations due to AEs at the initiation of AIT-tablets were numerically higher with vestibular administration than sublingual administration. Sublingual administration should remain the standard of care for subjects treated with AIT-tablets for AR/C.

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.

Anaphylaxis in Clinical Trials of Sublingual Immunotherapy Tablets

BACKGROUND

There is no consensus method to identify anaphylaxis in sublingual immunotherapy (SLIT) trials. Standardized Medical Dictionary for Regulatory Activities (MedDRA) queries (SMQs) are standardized groupings of MedDRA terms used in drug safety monitoring.

OBJECTIVE

To develop a method to identify potential anaphylaxis in SLIT-tablet trials using SMQ searches and case definitions of anaphylaxis adopted from the National Institute of Allergy and Infectious Disease.

METHODS

The SMQ search tool contained 2 criteria including treatment-emergent adverse events (AEs): (1) narrow MedDRA terms related to anaphylaxis and (2) all AEs with broad MedDRA terms from at least 2 of 3 categories (respiratory/skin/cardiovascular) occurring on the same day. Criteria were applied to a pooled data set of all subjects from 48 timothy grass, ragweed, house dust mite, and tree SLIT-tablet trials (SLIT-tablet, N = 8200; placebo, N = 7033). Additional search strategies were any treatment-emergent AE with MedDRA preferred term "hypersensitivity" and epinephrine administrations. Identified potential cases underwent blinded independent medical expert review. Nonanaphylaxis cases were designated local AEs or mild to moderate systemic reactions.

RESULTS

Using the SMQ search tool and after subsequent medical review, 8 anaphylaxis cases were identified; 3 were considered treatment-related, resulting in a proportion of anaphylaxis cases/subject of 0.02% (2 of 8200) with SLIT-tablet and 0.01% (1 of 7033) with placebo. One additional anaphylaxis case related to SLIT-tablet was identified by the preferred term "hypersensitivity." The 3 anaphylaxis cases associated with SLIT-tablet treatment were not life-threatening. The epinephrine administration rate was 17 of 8200 (0.2%) with SLIT-tablet treatment and 2 of 7033 (0.03%) with placebo.

CONCLUSIONS

SMQ search criteria for identifying potential anaphylaxis related to SLIT were developed. Anaphylaxis was rare for SLIT-tablets.

Allergic Rhinitis: Tailoring Immunotherapy Through Innovative Diagnostics

Allergic rhinitis (AR) is a chronic ailment triggered by immunoglobulin E (IgE)-mediated reactions to allergens. Generally, AR is accompanied by asthma and conjunctivitis. The risk factors of AR include both inhalant and occupational allergens and genetic factors. Although AR is not a life-threatening condition, it poses a significant risk of morbidity and hampers work-related performance. Currently, the diagnosis of AR is based on clinical history and physical examination of the patients. Furthermore, several laboratory tests such as skin pricking test (SPT), nasal allergen challenge (NAC), and computed tomography (CT) are also recommended in some cases. Nasal cytology can aid in the differentiation of rhinitis because of allergy or infection. Apart from this, molecular diagnostic modalities such as basophil activation test (BAT) and Immune Solid-Phase Allergy Chip (ISAC) can also be employed for the confirmatory diagnosis of AR. Immunotherapy has demonstrated efficacy in the management of AR, with only mild side effects. With the advancement in the diagnostic realm of AR, personalized treatment approach has also gained significant popularity. Immunotherapy is gaining evidence on becoming a personalized treatment approach for the management of AR. This article provides a comprehensive overview, aiming to bridge the gap between evolving diagnostics and personalized therapeutic strategies for allergic rhinitis.

Safety of allergen immunotherapy in children

PURPOSE OF REVIEW

The current review discusses allergen immunotherapy (AIT) safety in children.

RECENT FINDINGS

AIT is a well tolerated and effective treatment for pediatric allergic conditions. While mostly well tolerated, severe reactions and near fatal reactions may occur with subcutaneous immunotherapy (SCIT) once in every 160 000 visits. Sublingual immunotherapy (SLIT) is associated more with local side effects, but severe systemic reactions, including anaphylaxis, have been rarely reported. Providing informed consent, recognizing risk factors for severe systemic reactions, such as severe or uncontrolled asthma, and mitigating the risk of severe reactions are important components to improving the safety of AIT.

SUMMARY

Overall, AIT is well tolerated in children, and data suggest that the incidence of systemic reactions in children receiving SCIT is no less than mixed populations of adult and pediatric patients. SLIT carries less risk for systemic reactions, and local oral site-application reactions are usually mild and resolve within 15 days of treatment.

Effectiveness of sublingual immunotherapy with house dust mite drops in asthmatic children at different ages

Background

Respiratory allergies in children, such as asthma and rhinitis, are becoming progressively common every year. Recent studies found that pediatric patients with asthma receiving regular medication and specific immunotherapy (SIT) had improved therapeutic outcomes in a wide age range. However, there are few studies that have examined the effectiveness of SIT treatment in children with allergic asthma at different ages in terms of the degree of asthma control, improvements in lung function, and changes in exhaled nitric oxide (FeNO).

Method

A total of 200 asthmatic pediatric patients who had been receiving regular treatment for at least a year were split into the observation and the control groups, which depended on whether sublingual immunotherapy was added based on conventional treatment medicines. The children who were divided by an age cut-off of 6 years old in these two groups were compared before and after therapy based on the exhaled levels of FeNO, pulmonary function, visual analog scale, medication scores, daytime and nighttime ratings of asthma symptom, and rhinitis symptom scores.

Results

Before treatment, there was no significant difference between the observation group and the control group in various indicators of the patients under 6 years old; and in the older children (6-16 years old) group, the scores of FVC, FEV1, and FEF25 in the observation group were significantly lower than those in the control group (P < 0.05). The FEF75, FEF50, FEF25, and MMEF75/MMEF25 indexes in the observation group were significantly higher than those in the control group after treatment (P < 0.05), but there was no statistical significance in other indexes (P > 0.05). The scores of ACT, FEF75, FEF50, MMEF72/MMEF25, and FeNO in the observation group were all higher than those in the control group after treatment (P < 0.05), and the differences in other indexes were not statistically significant (P > 0.05). Between the young-age group and the elder group, there was no significant difference in all indexes in the observation group before and after treatment (P > 0.05).

Conclusion

Children with asthma of all ages can considerably benefit from sublingual immunotherapy. Specifically, younger patients showed greater tendency on the improvement of small airway resistance, whereas school-age children with asthma significantly improved their small airway resistance as well as their asthma control and inflammation alleviation.

Clinical and experimental treatment of allergic asthma with an emphasis on allergen immunotherapy and its mechanisms

Allergen immunotherapy (AIT) is currently the only form of treatment that modifies allergic asthma. Pharmacotherapy alone seeks to control the symptoms of allergic asthma, allergic rhinitis, and other atopic conditions. In contrast, AIT can induce long-term physiological modifications through the immune system. AIT enables individuals to live improved lives many years after treatment ends, where they are desensitized to the allergen(s) used or no longer have significant allergic reactions upon allergen provocation. The leading forms of treatment with AIT involve injections of allergen extracts with increasing doses via the subcutaneous route or drops/tablets via the sublingual route for several years. Since the initial attempts at this treatment as early as 1911 by Leonard Noon, the mechanisms by which AIT operates remain unclear. This literature-based review provides the primary care practitioner with a current understanding of the mechanisms of AIT, including its treatment safety, protocols, and long-term efficacy. The primary mechanisms underlying AIT include changes in immunoglobulin classes (IgA, IgE, and IgG), immunosuppressive regulatory T-cell induction, helper T cell type 2 to helper T cell type 1 cell/cytokine profile shifts, decreased early-phase reaction activity and mediators, and increased production of IL-10, IL-35, TGF-β, and IFN-γ. Using the databases PubMed and Embase, a selective literature search was conducted searching for English, full-text, reviews published between 2015 and 2022 using the keywords (with wildcards) "allerg*," "immunotherap*," "mechanis*," and "asthma." Among the cited references, additional references were identified using a manual search.

Deciphering Differential Behavior of Immune Responses as the Foundation for Precision Dosing in Allergen Immunotherapy

Like in many fields of medicine, the concept of precision dosing has re-emerged in routine practice in allergology. Only one retrospective study on French physicians' practice has addressed this topic so far and generated preliminary data supporting dose adaptation, mainly based on experience, patient profile understanding and response to treatment. Both intrinsic and extrinsic factors shape the individual immune system response to allergen immunotherapy (AIT). Herein, we focus on key immune cells (i.e., dendritic cells, innate lymphoid cells, B and T cells, basophils and mast cells) involved in allergic disease and its resolution to further understand the effect of AIT on the phenotype, frequency or polarization of these cells. We strive to discriminate differences in immune responses between responders and non-responders to AIT, and discuss the eligibility of a non/low-responder subset for dose adaptation. A differential behavior in immune cells is clearly observed in responders, highlighting the importance of conducting clinical trials with large cohorts of well-characterized subjects to decipher the immune mechanism of AIT. We conclude that there is a need for designing new clinical and mechanistic studies to support the scientific rationale of dose adaptation in the interest of patients who do not properly respond to AIT.

Sensitisation profile of Chinese allergic rhinitis patients and effectiveness of a joint allergy-ENT clinic

Purpose

House dust mite (HDM) is the predominant cause of allergic rhinitis (AR) in Hong Kong but remains under-diagnosed and -treated. The association between patient-reported outcome measures (PROMs) and nasoendoscopy findings for AR have also not been investigated. This study investigated the demographics, sensitisation patterns, quality of life, use of sublingual immunotherapy and the association of PROMs and nasoendoscopy findings in AR patients through the first allergist-otorhinolaryngologists AR joint (ARJ) clinic in Hong Kong.

Methods

This single-centred, retrospective observational study was conducted between January 2021 and December 2021. Clinical data from AR patients attending the ARJ clinic were analysed to identify the prevalence of HDM allergens, change in PROMs and the association of PROMs with nasoendoscopy scores.

Results

The three most common sensitising HDM allergens were Dermatophagoides pterynosinus (94.4%), Dermatophagoides farinae (88.9%) and Euroglyphus maynei (88.9%). At the 13- to 32-week follow-up (median 28 weeks), patients who attended the ARJ clinic had significant improvement in Total Nasal Symptom Score (TNSS; p = 0.038). The visual analogue scale (VAS) was associated with nasoendoscopy score (p = 0.018). Patients using SLIT (sublingual immunotherapy) showed overall improvements in PROMs.

Conclusion

The ARJ clinic significantly improved AR symptoms. SLIT was effective and safe for patients who failed conventional treatments. VAS positively correlated with nasoendoscopy findings. Testing for Dermatophagoides pterynosinus as a single agent during skin testing was sufficient for the diagnosis of HDM AR and should be prioritized when resources are restricted. Further studies should be done to investigate the treatment outcome of AR patients and the effectiveness of SLIT in the Chinese population.

Supplementary Information

The online version of this article (10.1007/s40629-022-00218-5) contains supplementary material, which is available to authorized users.

Recent Updates of Immunotherapy for Allergic Rhinitis in Children

Purpose of Review

Allergen immunotherapy (AIT) is a novel treatment approach with disease-modifying and preventative benefits that are not shared with other strategies for treating allergic illnesses. It has been demonstrated to be safe and effective in children. This review provides the most recent information on AIT in children as well as any pertinent updates.

Recent Findings

Although there is not a standard way to begin AIT, there are clear indications for AIT. Each case needs to be evaluated on its own by weighing the pros and downsides. AIT has been proven to significantly improve symptoms and quality of life in children with allergic illness, reduce medication use, stop the development of new allergen sensitizations, and stop the progression of allergic rhinitis to asthma. Novel approaches are under investigation to overcome some known AIT disadvantages.

Summary

This review provides a thorough summary of the most recent research and updates on AIT in children.

Immunotherapy in the Treatment of Allergic Rhinitis in Children

Allergic rhinitis (AR) is an inflammation of the nasal membranes characterized by multiple allergic symptoms. It is a widespread health problem that affects patients' ability to engage in social and physical activity, which lowers their quality of life. The pathophysiology of AR is complex and requires sensitization and the development of a specific immune response to the allergen. Allergen-specific immunotherapy (AIT) is a therapeutic method that induces specific immune tolerance to allergens. The objectives of this review are to demonstrate the mechanism of action of immunotherapy, explain how it alleviates clinical symptoms of allergic rhinitis, list the indications and contraindications of immunotherapy in the treatment of allergic rhinitis, and identify different modalities of allergen immunotherapy, their disease-modifying effects, as well as their potential risks and benefits. The review of the literature highlights that T-cell and B-cell responses to inhaled allergens are altered by AIT, which decreases both early and late reactions to allergen exposure. To induce clinical and immunologic tolerance, especially in the pediatric age, escalating dosages of the causing allergen are administered subcutaneously or sublingually. AIT is indicated for severe persistent AR when avoidance measures and medications are inadequate to control the symptoms. To conclude, AIT is a disease-modifying therapy that is safe and effective for the treatment of allergic rhinitis. It is indicated when the symptoms are uncontrolled or when there are undesirable effects from pharmacotherapy.

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.

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.

Delivery options for sublingual immunotherapy for allergic rhinoconjunctivitis: clinical considerations for North America

Background: Sublingual immunotherapy (SLIT) can be delivered via tablets (SLIT-T) or aqueous drops (SLIT-D). SLIT-D dosing recommendations using North American extracts were published in 2015. We review the 2015 recommendations in the context of recent research, and compare and contrast dosing, efficacy, safety, adherence, and cost of SLIT-T and SLIT-D for allergic rhinoconjunctivitis (ARC) in North America. Methods: Randomized controlled trials (RCT) of SLIT-D and SLIT-T trials were identified by a systematic PubMed search through March 1, 2022. Results: Dose-finding studies have been conducted for all approved SLIT-T; efficacy in North American populations was demonstrated in 11 RCTs. Approved SLIT-T are uniform internationally. Few dose-finding studies for SLIT-D have been conducted using North American extracts; efficacy was demonstrated in 2 RCTs. Extrapolation of dosing from SLIT-D studies conducted with extracts from other geographic regions is unreliable. Since the 2015 SLIT-D dosing recommendations, no new RCTs of SLIT-D have been conducted with North American extracts, whereas 6 SLIT-T RCTs have since been conducted in North America. Local allergic reactions are the most common adverse events with SLIT-T and SLIT-D, but both can induce systemic allergic reactions. Adherence to SLIT-D and SLIT-T remains a challenge. Patients must pay for SLIT-D directly, whereas SLIT-T is usually covered by insurance. Conclusion: As part of shared decision-making, patients should be informed about the scientific evidence supporting the use of SLIT-T and SLIT-D for ARC.

Allergen Immunotherapy in Young Children

PURPOSE OF REVIEW

Allergen immunotherapy (AIT) has been shown to be safe and effective in children and is a unique treatment strategy that has disease-modifying and preventative effects that are not shared with other treatment options for allergic diseases. This article reviews the present knowledge and relevant updates on AIT in children.

RECENT FINDINGS

Although there is no definite lower age limit for starting AIT, clear indications for AIT are established and each case should be considered individually by weighing risks and benefits. Documented short- and long-term benefits of AIT in children with allergic disease include significant improvement of symptoms and quality of life, and decreased use of medications as well as preventing the development of new allergen sensitizations and the progression of allergic rhinitis to asthma. This review provides a comprehensive overview of the present knowledge and key updates on AIT in the pediatric population.

Clinical efficiency of allergen-specific immunotherapy with fungal allergens in patients with chronic polypous rhinosinusitis against the background of fungal sensitization

Fungal flora is one of the causes of inflammatory, including polypous, processes in the nasal cavity. In this regard, studies aimed at reducing the effect of fungal sensitization (FS) on the course of chronic polypous rhinosinusitis (CPRS) are relevant. The objective of the study was to evaluate the effect of various treatment options on the clinical course of the disease in patients with chronic polypous rhinosinusitis against the background of sensitization to fungi. The study included 90 patients with chronic polypous rhinosinusitis in combination with FS. The patients were divided into two groups - the first clinical group (G1) and the second clinical group (G2). G1 patients received allergen-specific immunotherapy (ASIT) according to the scheme. G2 patients received basic treatment. Evaluation of the clinical efficiency of ASIT was made based on complaints, assessment of symptom severity on a visual analog scale (VAS), and rhinoendoscopic examination. The treatment outcomes were evaluated on a 4-point scale, with excellent results (4 points) - complete remission of the disease during the follow-up period (6-12 months); good (3 points) - exacerbation of the disease 1-2 times a year, in mild form and removed by expectant treatment; satisfactory (2 points) - the number of exacerbations did not decrease. The use of ASIT therapy is pathogenetically justified and leads to a significant improvement in the clinical condition of patients with CPRS with FS.

Molecular allergology and its impact in specific allergy diagnosis and therapy

Progressive knowledge of allergenic structures resulted in a broad availability of allergenic molecules for diagnosis. Component-resolved diagnosis allowed a better understanding of patient sensitization patterns, facilitating allergen immunotherapy decisions. In parallel to the discovery of allergenic molecules, there was a progressive development of a regulation framework that affected both in vitro diagnostics and Allergen Immunotherapy products. With a progressive understanding of underlying mechanisms associated to Allergen immunotherapy and an increasing experience of application of molecular diagnosis in daily life, we focus in analyzing the evidences of the value provided by molecular allergology in daily clinical practice, with a focus on Allergen Immunotherapy decisions.

Randomized controlled trial of ragweed sublingual immunotherapy tablet in the subpopulation of Canadian children and adolescents with allergic rhinoconjunctivitis

Background

Post hoc analyses of randomized placebo-controlled trials have demonstrated efficacy and tolerability of the ragweed sublingual immunotherapy (SLIT)-tablet in Canadian adults with ragweed pollen-induced allergic rhinitis/conjunctivitis (AR/C). This post hoc analysis evaluated the efficacy and tolerability of the ragweed SLIT-tablet in the subpopulation of Canadian children and adolescents with AR/C in a previously described randomized, double-blind, placebo-controlled trial.

Methods

The trial (NCT02478398) was conducted in North American and European children/adolescents ages 5–17 years with ragweed pollen-induced AR/C with or without asthma (FEV1 ≥ 80% predicted). Participants were randomized to daily ragweed SLIT-tablet (12 Amb a 1-U) or placebo for up to 28 weeks. The primary endpoint was the average total combined score (TCS; sum of rhinoconjunctivitis daily symptom score [DSS] and daily medication score [DMS]) during peak ragweed pollen season (RPS). Key secondary endpoints were TCS during the entire RPS, and DSS and DMS during peak RPS. Post hoc analyses of the primary and key secondary endpoints were conducted in the subpopulation of Canadian participants.

Results

Of the 1025 randomized participants, 246 (SLIT-tablet, n = 116; placebo, n = 130) were in the Canadian subpopulation. In the total study population, relative TCS (95% CI) improvement with ragweed SLIT-tablet versus placebo was − 38.3% (− 46.0%, − 29.7%; least square [LS] mean difference, − 2.73; P < 0.001) during peak RPS. In the Canadian subpopulation, relative TCS improvements with ragweed SLIT-tablet versus placebo were − 40.8% (− 54.5%, − 20.2%; LS mean difference, − 1.59; P = 0.001) during peak RPS and − 36.6% (− 50.2%, − 16.5%; LS mean difference, − 1.36; P = 0.002) during the entire RPS. DSS and DMS during peak RPS in the Canadian subpopulation improved with SLIT-tablet versus placebo by − 30.6% (− 45.2%, − 7.7%; LS mean difference, − 0.94; P = 0.010) and − 77.2% (− 97.5%, − 44.2%; LS mean difference, − 0.66; P = 0.003), respectively. No events of anaphylaxis, airway compromise, intramuscular epinephrine administration, eosinophilic esophagitis, or severe treatment-related systemic allergic reactions were reported in the overall population or Canadian subpopulation.

Conclusion

Efficacy and safety of the ragweed SLIT-tablet in Canadian children/adolescents with ragweed pollen-induced AR/C was consistent with the total study population. The ragweed SLIT-tablet resulted in clinically meaningful improvement in symptoms, decreased symptom-relieving medication use, and was well tolerated in Canadian children/adolescents.

Trial registration: clinicaltrials.gov, NCT02478398. Registered June 23, 2015, https://clinicaltrials.gov/ct2/show/NCT02478398?term=NCT02478398&draw=2&rank=1

[Allergen immunotherapy for atopic dermatitis]

Seit dem ersten Bericht über die Allergenimmuntherapie (AIT) durch Noon et al. vor 110 Jahren wurden zahlreiche klinische und grundlagenwissenschaftliche Studien durchgeführt, um die Effekte der einzigen kurativen Behandlung von Allergien zu untersuchen. Bei der atopischen Dermatitis (AD) findet sie jedoch nur selten Anwendung, obwohl es Evidenz dafür gibt, dass Aeroallergene zu Exazerbationen der Erkrankung beitragen können. Dieser Übersichtsbeitrag umfasst die aktuelle Studienlage, Metaanalysen und Leitlinienempfehlungen zur AIT bei AD-Patienten. Es zeigt sich eine große Heterogenität hinsichtlich Studiendesigns, Patientenkohorten, Allergenen, Applikationsformen und Endpunkten, wodurch die Vergleichbarkeit der Studien erschwert wird. Mehrere Untersuchungen zeigen eine positive Wirkung der AIT auf den Schweregrad der AD, was darauf hindeutet, dass zumindest eine Untergruppe von Patienten von der Behandlung profitieren kann. Weitere Entwicklungen auf dem Gebiet der AIT könnten dazu beitragen, dass die Therapie einen breiteren Einsatz bei AD-Patienten findet.

Allergic Rhinitis: What Do We Know About Allergen-Specific Immunotherapy?

Allergic rhinitis (AR) is an IgE-mediated disease that is characterized by Th2 joint inflammation. Allergen-specific immunotherapy (AIT) is indicated for AR when symptoms remain uncontrolled despite medication and allergen avoidance. AIT is considered to have been effective if it alleviated allergic symptoms, decreased medication use, improved the quality of life even after treatment cessation, and prevented the progression of AR to asthma and the onset of new sensitization. AIT can be administered subcutaneously or sublingually, and novel routes are still being developed, such as intra-lymphatically and epicutaneously. AIT aims at inducing allergen tolerance through modification of innate and adaptive immunologic responses. The main mechanism of AIT is control of type 2 inflammatory cells through induction of various functional regulatory cells such as regulatory T cells (Tregs), follicular T cells (Tfr), B cells (Bregs), dendritic cells (DCregs), innate lymphoid cells (IL-10⁺ ILCs), and natural killer cells (NKregs). However, AIT has a number of disadvantages: the long treatment period required to achieve greater efficacy, high cost, systemic allergic reactions, and the absence of a biomarker for predicting treatment responders. Currently, adjunctive therapies, vaccine adjuvants, and novel vaccine technologies are being studied to overcome the problems associated with AIT. This review presents an updated overview of AIT, with a special focus on AR.

Recent strategies driving oral biologic administration

INTRODUCTION

High patient compliance, noninvasiveness, and self-administration are the leading features of vaccine delivery through the oral route. The implementation of swift mass vaccination campaigns in pandemic outbreaks fascinates the use of oral vaccination. This approach can elicit both mucosal and systemic immune responses to protect against infection at the surface of the mucosa.

AREA COVERED

As pathogen entry and spread mainly occurs through the gastrointestinal tract (GIT) mucosal surfaces, oral vaccination may protect and limit disease spread. Oral vaccines target various potential mucosal inductive sites in the GIT, such as the oral cavity, gastric area, and small intestine. Orally delivered vaccines having subunit and nucleic acid pass through various GIT-associated risks, such as the biodegradation of biologics and their reduced absorption. This article presents a summarized review of the existing technologies and prospects for oral vaccination.

EXPERT OPINION

The intestinal mucosa focuses on current approaches, while future strategies target new mucosal sites, i.e. oral cavity and stomach. Recent developments in biologic delivery through the oral route and their potential use in future oral vaccination are mainly considered.

[Allergen immunotherapy: FAQs and facts]

Die Allergenimmuntherapie (AIT) ist – neben der oft nicht suffizient durchzuführenden Allergenmeidung – die einzige kausale Therapie Ig(Immunglobulin)E-vermittelter Allergien gegen Aeroallergene und Hymenopterengifte. Sie kann je nach Allergen als subkutane Injektion (subkutane Immuntherapie [SCIT]) oder über eine sublinguale Applikation (sublinguale Immuntherapie [SLIT]) erfolgen, kürzlich wurde zudem auch ein Verfahren zur oralen Immuntherapie zur Behandlung der Nahrungsmittelallergie zugelassen. Neben der korrekten Indikationsstellung (positive Anamnese und Diagnostik einer IgE-vermittelten Allergie, Allergenkarenz nicht ausreichend möglich) sind mögliche Kontraindikationen und Risikofaktoren zu beachten. Zudem kann es unter einer AIT zu – potenziell auch lebensgefährlichen – Nebenwirkungen kommen. Im Folgenden sollen häufig gestellte Fragen und Fakten zur Entscheidungsfindung für die Durchführung und zum Risikomanagement der AIT beleuchtet und unter Berücksichtigung der aktuellen Datenlage diskutiert werden.

Ragweed pollen induces allergic conjunctivitis immune tolerance in mice via regulation of the NF-κB signal pathway

AIM

To investigate the feasibility and mechanism of immune tolerance in allergic conjunctivitis.

METHODS

The allergic conjunctivitis immune tolerance mice model was established by ragweed pollen (RW) and the related cytokines were detected. The mice were divided into 9 groups and the maslinic acid (MA) or PBS were given for different group after modeling. The expression levels of chemokine ligand 5 (CCL5) and P-65 in the conjunctival tissue were analyzed by immunohistochemistry, quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot. The percentage of interleukin-17 (IL-17) and CD4+CD25+ in the splenocyte supernatant was analyzed by flow cytometry. Furthermore, the serum and splenocyte supernatant concentration of total-IgE, interleukin-10 (IL-10), and IL-17 was analyzed by enzyme linked immune response (ELISA).

RESULTS

After the model was established, symptoms of conjunctivitis were alleviated, the level of P-65, CCL5, IL-17, and total-IgE was raised, while the expression of IL-10, CD4+CD25+ was decreased. This result fully demonstrated that a typical IL-17/regulatory-T-cells (Treg cells) imbalance and NF-κB activation. When the NF-κB signal pathway was suppressed, it showed that there was a further relief of conjunctivitis in mice. At the same time, the expression of total-IgE, IL-17, and CCL5 was decreased and the expression of anti-inflammatory factor (IL-10, CD4+CD25+) was increased.

CONCLUSION

In the state of immune tolerance, symptoms of conjunctivitis in mice are alleviated, the Th-17 cells of allergic conjunctivitis mice are inhibited, and Treg cells activity is enhanced.

Recent development on the use of sublingual immunotherapy tablets for allergic rhinitis

OBJECTIVE

Allergic rhinitis (AR) is an immunoglobulin (Ig) E-mediated inflammatory condition that causes sneezing, nasal congestion, rhinorrhea, and nasal itch. Although subcutaneous immunotherapy for the treatment of AR has been in use and well established as a treatment modality, sublingual immunotherapy (SLIT) is increasingly considered to be the safer and more convenient alternative. Thus, the objective of this review is to describe recent findings pertaining to the use of SLIT tablets (SLIT-T) for AR.

DATA SOURCES

A database search (PubMed.gov) for articles published between January 1, 2017, and February 9, 2021, was conducted using the following key words: "allergic rhinitis," AND-ed "sublingual immunotherapy." Included were randomized placebo-controlled trials. Other experimental design studies were excluded.

STUDY SELECTIONS

A total of 11 randomized placebo-controlled trials were selected for full-text review and included in the analysis. All studies investigated the use of SLIT on patients with seasonal AR (4 tree pollen, 1 grass pollen, and 1 Japanese cedar) or perennial AR (3 house dust mite).

RESULTS

Our review of 7 recently published randomized placebo-controlled trials with 2348 subjects receiving SLIT reported increased efficacy, safety, supportive immunologic parameters (IgE and IgG4 pre- and posttreatment levels), and improved quality of life. All studies excluded subjects with overlapping seasonal or perennial allergens, a history of moderate-to-severe uncontrolled asthma, or reduced lung function.

CONCLUSION

Our review highlights that SLIT is a safe and effective treatment that considerably reduces symptoms and medication requirements in AR and improves quality of life.

Worldwide surveys on anaphylaxis to sublingual immunotherapy with house dust mite tablets are urgently needed

In the 1980s, a global number of 72 fatalities were reported in the UK and the USA following the application of subcutaneous immunotherapy (SCIT). This resulted in a significant limitation of SCIT use and in the search of other routes of administration, among which sublingual immunotherapy (SLIT) showed the best balance between efficacy and safety. Data from controlled studies suggest that tablets‐related anaphylaxis is an uncommon event. However, in the Eudravigilance (European database of suspected adverse drug reactions from Europe) we found reports of life‐threatening events or severe local reactions under SLIT increasing over the last few years. Therefore, all efforts to minimize the related risk have to be strongly encouraged.

Controversies in Allergy: A Pro/Con Review of Sublingual Allergen Immunotherapy and Allergic Asthma

Sublingual allergen immunotherapy (SLIT) is a therapeutic intervention used in the treatment of respiratory allergies, including asthma. Multiple randomized, double-blind, placebo controlled clinical trials have evaluated the efficacy and safety of SLIT for asthma. These data provide a good platform to appraise the evidence critically to evaluate the effect of SLIT in the management of asthma for the administration of SLIT by both SLIT drops and SLIT tablets, from a clinical perspective. In this clinical review, presented in a pro and con format, we examined (1) evidence from systematic reviews and meta-analyses; (2) clinical efficacy on asthma symptoms, asthma exacerbations, and quality of life; (3) clinical efficacy on reduction of asthma controller medication; (4) asthma severity; (5) safety profile; (6) long-term effect and prevention; (7) international guidelines, and (8) real-world evidence. Identified inconsistency in the data results from wide variations and differences in outcome measures, specific allergens, delivery approaches, schedules, and age groups. The house dust mite SLIT tablet demonstrated efficacy when it was used in the add-on management of house dust mite-associated allergic asthma in adults. Sublingual allergen immunotherapy for asthma may represent an important advance in incorporating a personalized medicine approach for patients with allergic asthma.

A Retrospective Nationwide Non-Interventional Study of an Aqueous Sublingual Immunotherapy Formulation Administered with a 200-µL Dosing Pump

Background

Convenient dosing is a key component of treatment adherence and thus efficacy and safety. Aqueous sublingual immunotherapy (SLIT) formulations can be administered with a dosing pump that delivers 200 µL of volume per actuation.

Objective

The objective of this study was to describe the use of Staloral^® 300 Rapid in its new dosing pump presentation and to evaluate the safety and satisfaction from both the patient and doctor.

Patients and Methods

We performed a retrospective non-interventional study in a population (aged 5 years or over) of individuals with allergic rhinitis or allergic asthma who were being treated with aqueous 300 index of reactivity SLIT formulations of various allergens (grass pollen, tree pollen, house dust mites). Based on a detailed, SLIT-specific, patient self-questionnaire (Quartis^®) and the inspection of medical records, we assessed the characteristics of the SLIT, safety, patient satisfaction and willingness to continue SLIT. The physician’s satisfaction with the treatment was measured on a 0–100 visual analogue scale. Adverse events were coded with the Medical Dictionary for Regulatory Activities.

Results

A total of 801 valid patients were included (52.4% male; mean ± standard deviation age: 25.9 ± 17.2 years; mean time since diagnosis: 4.56 ± 4.68 years; mean time using the previous dosing pump: 19.2 ± 13.0 months; time using the 200-µL dosing pump: 14.95 ± 3.80 months). Among the study population, 317 subjects comprised the paediatric subgroup (57%: male; mean age: 9.8 ± 2.5 years). Overall, 54 patients (6.7%) reported a total of 68 adverse events (including 51 gastrointestinal adverse events). The large majority of adverse events were mild, local and transient and did not require treatment. There were no severe adverse events. The level of patient satisfaction with the ease of SLIT administration was high (84.3% overall, and 82.6% in the paediatric subgroup). The mean ± standard deviation visual analogue scale score for physician satisfaction with the treatment was 70.6 ± 25.1 out of 100.

Conclusions

Administration of 300 index of reactivity SLIT with a 200-µL dosing pump is safe, well tolerated and associated with good levels of patient satisfaction.

Modulating Th2 Cell Immunity for the Treatment of Asthma

It is estimated that more than 339 million people worldwide suffer from asthma. The leading cause of asthma development is the breakdown of immune tolerance to inhaled allergens, prompting the immune system's aberrant activation. During the early phase, also known as the sensitization phase, allergen-specific T cells are activated and become central players in orchestrating the subsequent development of allergic asthma following secondary exposure to the same allergens. It is well-established that allergen-specific T helper 2 (Th2) cells play central roles in developing allergic asthma. As such, 80% of children and 60% of adult asthma cases are linked to an unwarranted Th2 cell response against respiratory allergens. Thus, targeting essential components of Th2-type inflammation using neutralizing antibodies against key Th2 modulators has recently become an attractive option for asthmatic patients with moderate to severe symptoms. In addition to directly targeting Th2 mediators, allergen immunotherapy, also known as desensitization, is focused on redirecting the allergen-specific T cells response from a Th2-type profile to a tolerogenic one. This review highlights the current understanding of the heterogeneity of the Th2 cell compartment, their contribution to allergen-induced airway inflammation, and the therapies targeting the Th2 cell pathway in asthma. Further, we discuss available new leads for successful targeting pulmonary Th2 cell responses for future therapeutics.

Oral Biologic Delivery: Advances Toward Oral Subunit, DNA, and mRNA Vaccines and the Potential for Mass Vaccination During Pandemics

Oral vaccination enables pain-free and self-administrable vaccine delivery for rapid mass vaccination during pandemic outbreaks. Furthermore, it elicits systemic and mucosal immune responses. This protects against infection at mucosal surfaces, which may further enhance protection and minimize the spread of disease. The gastrointestinal (GI) tract presents a number of prospective mucosal inductive sites for vaccine targeting, including the oral cavity, stomach, and small intestine. However, currently available oral vaccines are effectively limited to live-attenuated and inactivated vaccines against enteric diseases. The GI tract poses a number of challenges,including degradative processes that digest biologics and mucosal barriers that limit their absorption. This review summarizes the approaches currently under development and future opportunities for oral vaccine delivery to established (intestinal) and relatively new (oral cavity, stomach) mucosal targets. Special consideration is given to recent advances in oral biologic delivery that offer promise as future platforms for the administration of oral vaccines.

Essential role of submandibular lymph node dendritic cells in protective sublingual immunotherapy against murine allergy

While sublingual immunotherapy (SLIT) is known as an allergen-specific treatment for type-1 allergies, how it controls allergic pathogenesis remains unclear. Here, we show the prerequisite role of conventional dendritic cells in submandibular lymph nodes (ManLNs) in the effectiveness of SLIT for the treatment of allergic disorders in mice. Deficiency of conventional dendritic cells or CD4⁺Foxp3⁺ regulatory T (T_reg) cells abrogates the protective effect of SLIT against allergic disorders. Furthermore, sublingual antigenic application primarily induces antigen-specific CD4⁺Foxp3⁺ T_reg cells in draining ManLNs, in which it is severely impaired in the absence of cDCs. In ManLNs, migratory CD11b⁺ cDCs are superior to other conventional dendritic cell subsets for the generation of antigen-specific CD4⁺Foxp3⁺ T_reg cells, which is reflected by their dominancy in the tolerogenic features to favor this program. Thus, ManLNs are privileged sites in triggering mucosal tolerance mediating protect effect of SLIT on allergic disorders that requires a tolerogenesis of migratory CD11b⁺ conventional dendritic cells.

Noriaki Miyanaga and Hideaki Takagi et al. identify an essential role for migratory dendritic cells in mediating immunotherapy treatment against allergies in mice. They show that submandibular lymph node dendritic cells induce regulatory T cells, and their absence abrogates the effectiveness of immunotherapy treatment.

Safety, Efficacy, and Preventive Role of Subcutaneous and Sublingual Allergen Immunotherapy for the Treatment of Pediatric Asthma

Allergen-specific immunotherapy is currently the only treatment with the potential to modify and prevent progression of allergic asthma in children. In clinical practice, it is available in two forms: subcutaneous immunotherapy and sublingual immunotherapy. Trials and meta-analyses showed both the safety and the short- and long-term benefits of allergen-specific immunotherapy in asthmatic children. However, its use and role in asthma remains controversial, since studies are largely heterogeneous. This is mainly due to the lack of consensus on the optimal primary outcome to be considered for clinical trials evaluating the efficacy of allergen-specific immunotherapy in asthma. Therefore, well-conducted researchis needed using standardized and validated tools to evaluate key outcomes in asthmatic children.

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.

Presentation, diagnosis, and the role of subcutaneous and sublingual immunotherapy in the management of ocular allergy

Allergic eye disease or ocular allergy is a debilitating condition with a significant impact on quality of life and productivity. As atopy continues to be on the rise, primary care providers are likely to encounter increasing numbers of patients with allergic eye disease. This review outlines the classification and pathophysiology of allergic eye disease and its clinical presentation. This paper does not detail traditional first-line therapies of allergic eye disease but describes the interdisciplinary management between the eye-care provider and allergist. It is recommended that patients with ongoing signs and symptoms of ocular allergy despite first-line therapies be referred for allergen immunotherapy, as it is highly effective for treatment of allergic eye disease. Through induction of immune tolerance, allergen immunotherapy is a disease-modifying therapy that can result in long-term improvement of ocular allergy. A thorough literature review was conducted on the efficacy and safety of allergen immunotherapy, including subcutaneous immunotherapy and sublingual immunotherapy, and its role in allergic eye disease.

A 300 IR sublingual tablet is an effective, safe treatment for house dust mite-induced allergic rhinitis: An international, double-blind, placebo-controlled, randomized phase III clinical trial

BACKGROUND

Allergic rhinitis induced by house dust mites (HDMs) is a highly prevalent but often underdiagnosed and undertreated/untreated chronic disease. It often has a negative impact on sleep, work, leisure activities, and health-related quality of life. Allergen immunotherapy is a proven, safe treatment for respiratory allergies.

OBJECTIVE

We sought to assess the efficacy and safety of a 300 index of reactivity (IR) sublingual tablet formulation of Dermatophagoides pteronyssinus:Dermatophagoides farinae 1:1 extract in adolescents (aged ≥12) and adults with moderate to severe HDM-induced allergic rhinitis.

METHODS

In a phase III, international, double-blind, placebo-controlled, randomized clinical trial, participants received approximately 12 months of treatment with placebo or the 300 IR tablet. The primary end point was the average total combined score during 4 weeks at the end of the treatment period.

RESULTS

A total of 1607 participants were randomized, and 1476 (including 555 [37.6%] with concomitant mild controlled asthma at inclusion) comprised the full analysis set. Over the primary evaluation period, the least squares mean average total combined score in the 300 IR group (3.62) was significantly lower (P < .0001) than in the placebo group (4.35), with a relative least squares mean difference of -16.9% (95% CI, -24.0% to -9.2%). All prespecified secondary end points were consistently improved in the 300 IR group, relative to placebo. The 300 IR tablet was generally well tolerated. Treatment-related adverse events (mainly mild or moderate local reactions) were reported for 51.0% of the patients in the 300 IR group and 14.9% in the placebo group.

CONCLUSIONS

The 300 IR sublingual HDM tablet is an effective, safe treatment for HDM-induced allergic rhinitis.

Urticaria, Angioedema, and Anaphylaxis

Urticaria and, to a lesser extent, angioedema are common occurrences in the pediatric population. There are multiple causes of acute and chronic urticaria and angioedema. Most causes are benign, although they can be worrisome for patients and their parents. An allergist should evaluate acute urticaria and/or angioedema if there are concerns of an external cause, such as foods or medications. Chronic urticaria and angioedema can severely affect quality of life and should be managed aggressively with antihistamines and immunomodulators if poorly controlled. Chronic symptoms are unlikely to be due to an external cause. Anaphylaxis is a more serious allergic condition characterized by a systemic reaction involving at least 2 organ systems. Anaphylaxis should be initially managed with intramuscular epinephrine. Patients who experience anaphylaxis should be evaluated by an allergist for possible causes; if found, avoidance of the inciting antigen is the best management. All patients should also be given an epinephrine autoinjector and an action plan. Foods are a common cause of anaphylaxis in the pediatric population. New evidence suggests that the introduction of highly allergic foods is safe in infancy and should not be delayed. In addition, the early introduction of foods such as peanuts may help prevent the development of food allergies.

Bee Venom Immunotherapy: Current Status and Future Directions

Bee venom immunotherapy is the main treatment option for bee sting allergy. Its major limitations are the high percentage of allergic side effects and long duration, which are driving the development of novel therapeutic modalities. Three general approaches have been evaluated including the use of hypoallergenic allergen derivatives, adjunctive therapy, and alternative delivery routes. This article reviews preclinical and clinical evidence on the therapeutic potential of these new therapies. Among hypoallergenic derivatives, hybrid allergens showed a markedly reduced IgE reactivity in mouse models. Whether they will offer therapeutic benefit over extract, it is still not known since clinical trials have not been carried out yet. T cell epitope peptides have proven effective in small clinical trials. Major histocompatibility complex class II restriction was circumvented by using long overlapping or promiscuous T cell epitope peptides. However, the T cell-mediated late-phase adverse events have been reported with both short and longer peptides. Application of mimotopes could potentially overcome both T cell- and IgE-mediated adverse events. During this evolution of vaccine, there has been a gain in safety. The efficacy was further improved with the use of Toll-like receptor-activating adjuvants and delivery systems. In murine models, the association of allergen Api m 1 with cytosine-guanosine rich oligonucleotides stimulated strong T-helper type-1 response, whereas its encapsulation into microbubbles protected mice against allergen challenge. An intralymphatic administration of low-dose vaccine has shown the potential to decrease treatment from 5 years to only 12 weeks. Bigger clinical trials are needed to follow up on these results.

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

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

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.

30 years of sublingual immunotherapy

Allergen Immunotherapy (AIT) was introduced in clinical practice on an empirical basis more than 100 years ago. Since the first attempts, AIT was administered subcutaneously. Indeed, other routes of administration were proposed and studied, in particular to improve the safety, but only the sublingual route (SLIT) achieved a credibility based on evidence and was then accepted as a viable "alternative" option to the subcutaneous route. SLIT was largely used in clinical trials and clinical practice in this last 30 years. Thus, a large amount of data is available, coming from either controlled trials and postmarketing surveillance studies. It is clear that SLIT is overall effective, but it is also clear that the efficacy is not "class-related," as derived from meta-analyses, but restricted to each specific product. The 30-year lasting use of SLIT allowed to clarify many clinical aspects, such as efficacy, safety, use in asthma, regimens of administration, and optimal doses. In parallel, the mechanisms of action of AIT were elucidated, and new indications were proposed (eg food allergy, atopic dermatitis). In addition, the introduction of molecular-based diagnosis, allowed to better refine the prescription of SLIT, based on specific sensitization profiles. The present article will describe the origin and evolution of SLIT for respiratory allergy, taking into account the clinical context that suggested this form of treatment, the recently developed aspects, the future perspectives and unmet needs, This is not, therefore, a systematic review, rather a narrative historical description of the past history, and a look forward to the future opportunities.

Streptococcal H2O2 inhibits IgE-triggered degranulation of RBL-2H3 mast cell/basophil cell line by inducing cell death

Mast cells and basophils are central players in allergic reactions triggered by immunoglobulin E (IgE). They have intracellular granules containing allergic mediators (e.g., histamine, serotonin, inflammatory cytokines, proteases and β-hexosaminidase), and stimulation by IgE-allergen complex leads to the release of such allergic mediators from the granules, that is, degranulation. Mast cells are residents of mucosal surfaces, including those of nasal and oral cavities, and play an important role in the innate defense system. Members of the mitis group streptococci such as Streptococcus oralis, are primary colonizers of the human oral cavity. They produce hydrogen peroxide (H₂O₂) as a by-product of sugar metabolism. In this study, we investigated the effects of streptococcal infection on RBL-2H3 mast cell/basophil cell line. Infection by oral streptococci did not induce degranulation of the cells. Stimulation of the RBL-2H3 cells with anti-dinitrophenol (DNP) IgE and DNP-conjugated human serum albumin triggers degranulation with the release of β-hexosaminidase. We found that S. oralis and other mitis group streptococci inhibited the IgE-triggered degranulation of RBL-2H3 cells. Since mitis group streptococci produce H₂O₂, we examined the effect of S. oralis mutant strain deficient in producing H₂O_2, and found that they lost the ability to suppress the degranulation. Moreover, H₂O₂ alone inhibited the IgE-induced degranulation. Subsequent analysis suggested that the inhibition of degranulation was related to the cytotoxicity of streptococcal H₂O₂. Activated RBL-2H3 cells produce interleukin-4 (IL-4); however, IL-4 production was not induced by streptococcal H₂O₂. Furthermore, an in vivo study using the murine pollen-induced allergic rhinitis model suggested that the streptococcal H₂O₂ reduces nasal allergic reaction. These findings reveal that H₂O₂ produced by oral mitis group streptococci inhibits IgE-stimulated degranulation by inducing cell death. Consequently, streptococcal H₂O₂ can be considered to modulate the allergic reaction in mucosal surfaces.

Clinical aspects of sublingual immunotherapy tablets and drops

BACKGROUND

Sublingual immunotherapy (SLIT) is administered via tablets (SLIT-T) or liquid drops (SLIT-D). In North America, currently 4 SLIT-T formulations are approved by the US Food and Drug Administration for allergy immunotherapy, and SLIT-D is an off-label use of subcutaneous immunotherapy (SCIT) extracts.

OBJECTIVE

To compare and contrast aspects of SLIT-T and SLIT-D, including physical characteristics, mechanism of action, dosing, efficacy, safety, adherence, and cost.

DATA SOURCES

PubMed literature review (no limits), product prescribing information, and manufacturer websites.

STUDY SELECTIONS

Publications related to physical characteristics, mechanism of action, dosing, efficacy, safety, and adherence.

RESULTS

Published evidence indicates that tablet and drop formulations differ in regard to physical characteristics, dosing, and strength of evidence for efficacy. Whether there are any differences in absorption and mechanism of action between the 2 formulations is currently unknown. Optimal dosing, efficacy, and safety have been established for SLIT-T. In contrast, in North America there is little support for efficacy of SLIT-D from randomized double-blind, placebo-controlled trials, and dose ranges have not been appropriately evaluated. SLIT-T treats a single allergen, whereas in the United States SLIT-D often contains multiple allergens to treat polysensitization. The safety profiles of SLIT-T and SLIT-D appear similar, and both formulations are considered safer than SCIT.

CONCLUSION

Professional guidelines should make a clear distinction between SLIT-T and SLIT-D in their recommendations to minimize confusion with the umbrella term SLIT.

Approach to Patients with Allergic Rhinitis: Testing and Treatment

This article evaluates the role of allergen immunotherapy (AIT) in the treatment of allergic rhinitis (AR). AIT has been shown to be effective in treating AR symptoms with resultant improvements in overall quality of life, comorbid illnesses, and medication requirements. Persistent clinical benefits have been shown years after AIT treatment discontinuation. AIT may prevent the progression of AR to asthma. AIT may more cost-effective than pharmacotherapy. Multiple individual studies and systematic reviews provide strong evidence for the clinical effectiveness of AIT in the treatment of AR. Cost-effectiveness and disease modification of AIT compared with standard drug treatment are additional advantages.

Allergen-specific Immunotherapy for Inhalant Allergens in Children

Allergen-specific immunotherapy (AIT) for aeroallergens consists of the administration of standardized allergen extracts to patients with respiratory IgE-mediated diseases to the same allergen in order to achieve immune tolerance to the allergen and prevent the onset of symptoms. AIT is usually delivered by sublingual (SLIT), subcutaneous (SCIT) route. AIT with one or multiple allergens currently represents the only causal treatment able to change the natural history of allergic airway diseases. Significant progresses have been made in terms of AIT efficacy and safety. In this paper, mechanisms of action, indication and side effects of allergen immunotherapy are reviewed. SLIT and SCIT have been found to be effective in the treatment of asthma and rhinoconjunctivitis due to inhalant allergens. The route of AIT administration should be selected on availability, cost (dependent from the local health system), tolerability (better for SLIT), patient's preference (injections are less accepted in young children), and adherence (higher for SCIT beyond pediatric age). However, it should be taken into account that metanalyses on AIT do not consider that effectiveness and safety depend upon the product chosen for treatment. Each product should be separately assessed to avoid generalization on administration routes or age group that may affect the decision.