Antihistamine premedication in specific cluster immunotherapy: a double-blind, placebo-controlled study

KAAACI Guidelines for Allergen Immunotherapy

Allergen immunotherapy (AIT) is a causative treatment for various allergic diseases such as allergic rhinitis, allergic asthma, and bee venom allergy that induces tolerance to offending allergens. The need for uniform practice guidelines in AIT is continuously growing because of the increasing discovery of potential candidates for AIT and evolving interest in new therapeutic approaches. This guideline is an updated version of the Korean Academy of Asthma Allergy and Clinical Immunology recommendations for AIT published in 2010. This updated guideline proposes an expert opinion by allergy, pediatrics, and otorhinolaryngology specialists with an extensive literature review. The guideline deals with basic knowledge and methodological aspects of AIT, including mechanisms, clinical efficacy, patient selection, allergens extract selection, schedule and doses, management of adverse reactions, efficacy measurements, and special consideration in pediatrics. The guidelines for sublingual immunotherapy will be covered in detail in a separate article.

A novel dose-adjustment protocol for interrupted subcutaneous immunotherapy for allergic rhinitis

Background: This study aimed to develop a novel dose strategy for subcutaneous immunotherapy to reduce medical waste and financial burdens for patients who are required to restart subcutaneous immunotherapy. Patients & methods: A prospective, nonrandomized concurrent controlled trial was performed to assess the safety and advantages of the novel dose-adjustment protocol compared with the conventional one. 76 subjects were grouped to receive novel or conventional dose-adjustment protocols. Results: The injections, visits and time needed to reach the pre-established dose with the novel regimen were decreased. Furthermore, there were no differences in side reactions between the two groups. Conclusion: The novel protocol seemed safe and well tolerated, offering the advantages of time efficiency and reduced healthcare costs.

EAACI Molecular Allergology User's Guide 2.0

Since the discovery of immunoglobulin E (IgE) as a mediator of allergic diseases in 1967, our knowledge about the immunological mechanisms of IgE-mediated allergies has remarkably increased. In addition to understanding the immune response and clinical symptoms, allergy diagnosis and management depend strongly on the precise identification of the elicitors of the IgE-mediated allergic reaction. In the past four decades, innovations in bioscience and technology have facilitated the identification and production of well-defined, highly pure molecules for component-resolved diagnosis (CRD), allowing a personalized diagnosis and management of the allergic disease for individual patients. The first edition of the "EAACI Molecular Allergology User's Guide" (MAUG) in 2016 rapidly became a key reference for clinicians, scientists, and interested readers with a background in allergology, immunology, biology, and medicine. Nevertheless, the field of molecular allergology is moving fast, and after 6 years, a new EAACI Taskforce was established to provide an updated document. The Molecular Allergology User's Guide 2.0 summarizes state-of-the-art information on allergen molecules, their clinical relevance, and their application in diagnostic algorithms for clinical practice. It is designed for both, clinicians and scientists, guiding health care professionals through the overwhelming list of different allergen molecules available for testing. Further, it provides diagnostic algorithms on the clinical relevance of allergenic molecules and gives an overview of their biology, the basic mechanisms of test formats, and the application of tests to measure allergen exposure.

Risk of anaphylaxis in cluster vs standard subcutaneous multiallergen immunotherapy

BACKGROUND

Cluster schedules for subcutaneous allergen immunotherapy (AIT) require significantly fewer injections, but there have been conflicting reports regarding the risk of systemic reactions (SR).

OBJECTIVE

To compare the incidence of SRs during the build-up stages of multiallergen standard vs cluster immunotherapy.

METHODS

Data on SRs were collected prospectively from 91 urban adult patients who underwent either standard or cluster AIT at the Johns Hopkins Allergy and Asthma Center from 2014 to 2022. The SRs were recorded during the build-up phase and compared for both protocols using Pearson's χ², Fisher exact test, and multivariate logistic regression models.

RESULTS

Overall, SR rates were 21% for patients in the standard schedule and 37% for patients in the cluster immunotherapy schedule, which was not statistically different (P = .08). However, the SR rate for each injection was 0.69% per injection in the standard protocol and 2.29% per injection in the cluster schedule (incident rate ratio = 3.3). All SRs (100%) in both groups occurred in the second half of the build-up phase. Multivariate regression revealed that the target prescription protein nitrogen units and the number of allergens in the treatment vial did not influence SR rates (odds ratio = 1.00 and 1.06, respectively).

CONCLUSION

The overall incidence of SR was not statistically different for cluster and standard AIT protocols. However, because cluster patients received approximately half the number of injections, the risk for SR per individual injection is more than 3-fold higher than that of standard immunotherapy.

Accelerated/rush allergen immunotherapy

Accelerated allergy shot schedules for inhalant and venom allergens provide individuals with allergy symptom relief but in a shorter time frame than conventional therapy. Accelerated immunotherapy (IT) protocols allow patients to reach therapeutic doses in a shorter time frame while improving adherence and reducing direct costs (e.g., fewer office visits and medications) and indirect costs (e.g., less travel time, missed work or school). Rush IT and cluster IT are believed to work through mechanisms similar to conventional subcutaneous IT (SCIT). The risk for severe systemic reactions during accelerated IT is low when appropriately administered; however, life-threatening and fatal reactions do occur. To reduce the incidence of systemic allergic reactions during cluster and rush IT protocols, premedication is recommended. It is important to exclude individuals at high risk such as those with poorly controlled asthma or those who are on β-blockers to mitigate the risk for developing systemic allergic reactions. However, accelerated SCIT regimens offer increased convenience, faster improvement in allergy symptoms, and the potential to reduce health-care costs while providing equivalent safety outcomes compared with conventional IT protocols.

Systemic Allergic Reactions and Anaphylaxis Associated with Allergen Immunotherapy

Subcutaneous allergen immunotherapy (SCIT) is a proven treatment of allergic rhinitis, asthma, atopic dermatitis, and prevention of Hymenoptera venom anaphylaxis. The known benefit of SCIT, however, must be considered in each patient relative to the potential risks of systemic allergic reactions (SRs). A mean of 1 SR per 1000 injection visits (0.1%) was estimated to occur between 2008 and 2018. Life-threatening anaphylactic events are estimated to occur in 1/160,000 injection visits. The factors that contribute to SRs and fatal reactions (FRs) are reviewed. Risk management strategies are proposed to prevent and decrease future SCIT associated with SRs, anaphylaxis, and FR.

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.

An Approach to the Office-Based Practice of Food Oral Immunotherapy

Oral immunotherapy (OIT) provides an active treatment option for patients with food allergies. OIT may improve quality of life and raise the threshold at which a patient with food allergy may react to an allergen, but it is a rigorous therapy that requires a high degree of commitment by the clinician, patients, and families. Recent guidelines from the Canadian Society for Allergy and Clinical Immunology have provided a framework for the ethical, evidence-based, and patient-oriented clinical practice of OIT, and the European Academy of Allergy, Asthma, and Immunology guidelines have also recommended that OIT can be used as a potential treatment. The recent Food and Drug Administration approval of an OIT pharmaceutical has accelerated the adoption of OIT. This review provides a summary of the recent Canadian Society for Allergy and Clinical Immunology guidelines and a consensus of practical experience of clinicians across the United States and Canada related to patient selection, office and staff preparation, the general OIT process, OIT-related reaction management, and treatment outcomes.

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.

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.

Anaphylaxis-a 2020 practice parameter update, systematic review, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) analysis

Anaphylaxis is an acute, potential life-threatening systemic allergic reaction that may have a wide range of clinical manifestations. Severe anaphylaxis and/or the need for repeated doses of epinephrine to treat anaphylaxis are risk factors for biphasic anaphylaxis. Antihistamines and/or glucocorticoids are not reliable interventions to prevent biphasic anaphylaxis, although evidence supports a role for antihistamine and/or glucocorticoid premedication in specific chemotherapy protocols and rush aeroallergen immunotherapy. Evidence is lacking to support the role of antihistamines and/or glucocorticoid routine premedication in patients receiving low- or iso-osmolar contrast material to prevent recurrent radiocontrast media anaphylaxis. Epinephrine is the first-line pharmacotherapy for uniphasic and/or biphasic anaphylaxis. After diagnosis and treatment of anaphylaxis, all patients should be kept under observation until symptoms have fully resolved. All patients with anaphylaxis should receive education on anaphylaxis and risk of recurrence, trigger avoidance, self-injectable epinephrine education, referral to an allergist, and be educated about thresholds for further care.

Decision-making for pediatric allergy immunotherapy for aeroallergens: a narrative review

There has been exciting progress in diagnosis and in the treatment of allergic patients. The objective of this review is to summarize the most relevant contributions in the past 10 years with a special focus on the pediatric population allergic to aeroallergens and provide the most relevant references and practical issues for the decision-making. Current guidelines on allergy diagnosis recommend a thorough clinical history as the first step, followed by allergen extract testing using an in vivo prick test and/or an in vitro specific IgE test. Molecular diagnosis is recommended when previous tests are inconclusive. In practice, the most important factors to decide the AIT treatment are the actual intensity and duration of the patient's symptoms and the availability of appropriate AIT products for the patient's sensitization profile at high allergen concentrations and with confirmed efficacy and safety from clinical trials. This document summarizes outstanding references for allergic immunotherapy decision-making and provides summary tables and figures analyzing the most important factors related to the decision for allergen immunotherapy and the safety risks related. The experts concluded that AIT is efficacious and safe for the treatment of allergic patients that is available for the most frequent aeroallergens.What is Known:• The prevalence of allergic asthma and rhinitis in children has increased in recent decades.• The efficacy and safety of allergen immunotherapy has been shown in multiple studies and systematic reviews.What is New:• This document summarizes outstanding references for allergic immunotherapy decision-making and provides summary tables and figures analyzing the most important factors related to the decision for allergen immunotherapy and the safety risks related. Recommendations of expert authors for the decision of the patients more suitable for allergen immunotherapy are included.

Chinese Society of Allergy Guidelines for Diagnosis and Treatment of Allergic Rhinitis

Allergic rhinitis (AR) is a global health problem that causes major illnesses and disabilities worldwide. Epidemiologic studies have demonstrated that the prevalence of AR has increased progressively over the last few decades in more developed countries and currently affects up to 40% of the population worldwide. Likewise, a rising trend of AR has also been observed over the last 2-3 decades in developing countries including China, with the prevalence of AR varying widely in these countries. A survey of self-reported AR over a 6-year period in the general Chinese adult population reported that the standardized prevalence of adult AR increased from 11.1% in 2005 to 17.6% in 2011. An increasing number of Journal Articles and imporclinical trials on the epidemiology, pathophysiologic mechanisms, diagnosis, management and comorbidities of AR in Chinese subjects have been published in international peer-reviewed journals over the past 2 decades, and substantially added to our understanding of this disease as a global problem. Although guidelines for the diagnosis and treatment of AR in Chinese subjects have also been published, they have not been translated into English and therefore not generally accessible for reference to non-Chinese speaking international medical communities. Moreover, methods for the diagnosis and treatment of AR in China have not been standardized entirely and some patients are still treated according to regional preferences. Thus, the present guidelines have been developed by the Chinese Society of Allergy to be accessible to both national and international medical communities involved in the management of AR patients. These guidelines have been prepared in line with existing international guidelines to provide evidence-based recommendations for the diagnosis and management of AR in China.

EAACI Guidelines on Allergen Immunotherapy: Allergic rhinoconjunctivitis

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

Clinical efficacy of immunotherapy in allergic rhinitis

BACKGROUND

Aeroallergen immunotherapy (AIT) should be considered for patients who exhibit symptoms of allergic rhinitis (AR), rhinoconjunctivitis, and/or asthma after natural exposure to allergens and who also demonstrate specific immunoglobulin E antibodies against relevant allergens.

METHODS

In this paper, clinical efficacy of immunotherapy in allergic rhinitis is reviewed.

RESULT

Subcutaneous allergen immunotherapy (SCIT) is effective for seasonal and perennial AR. Sustained effectiveness requires several years of treatment. SCIT may prevent the development of allergic asthma in children with AR. Sublingual allergen immunotherapy (SLIT) is currently considered an alternative treatment to the subcutaneous route. The use of SLIT has been included in international guidelines for the treatment of AR with or without conjunctivitis.

CONCLUSION

Patients treated with SCIT are at risk of both local and systemic adverse reactions; however, in most cases, symptoms are readily reversible if they are recognized early and treated promptly. The safety profile of SLIT is good; therefore, SLIT can be self-administered by patients in their homes. In this article, we reviewed the efficacy and safety of allergen immunotherapy.

H1-antihistamines Reduce Progression to Anaphylaxis Among Emergency Department Patients With Allergic Reactions

OBJECTIVES

H1-antihistamines (H1a) can be used to treat emergency department (ED) patients with allergic reactions; however, this is inconsistently done, likely because there is no evidence that this therapy has an impact on serious outcomes. Among ED patients initially presenting with allergic reactions, we investigated whether H1a were associated with lower rates of progression to anaphylaxis.

METHODS

This was a retrospective cohort study conducted at two urban Canadian EDs from April 1, 2007, to March 31, 2012. We included consecutive adult patients with allergic reactions while excluding those presenting with anaphylaxis, according to prespecified criteria. The primary outcome was the proportion of patients who subsequently developed anaphylaxis during medical care, either by emergency medical services (EMS) or in the ED. A prespecified subgroup analysis excluded patients who received H1a prior to EMS or ED contact. We compared those who received H1a and those who did not and used multivariable regression and propensity score adjustment techniques to compare outcomes.

RESULTS

Of 2,376 overall patients included, 1,880 (79.1%) were managed with H1a. Of the latter group, 36 of 1,880 (1.9%) developed anaphylaxis, compared to 17 of 496 (3.4%) in the non-H1a-treated group (adjusted odds ratio [AOR] = 0.34, 95% confidence interval [CI] = 0.17-0.70; number needed to treat [NNT] to benefit = 44.74, 95% CI = 35.36-99.67). In the subgroup analysis of 1,717 patients who did not receive H1a prior to EMS or ED contact, a similar association was observed (AOR = 0.26, 95% CI = 0.10-0.50; NNT to benefit 38.20, 95% CI = 32.58-55.24).

CONCLUSIONS

Among ED patient with allergic reactions, H1a administration was associated with a lower likelihood of progression to anaphylaxis. These data indicate that early H1a treatment in the ED or prehospital setting may decrease progression to anaphylaxis.

A review of clinical efficacy, safety, new developments and adherence to allergen-specific immunotherapy in patients with allergic rhinitis caused by allergy to ragweed pollen (Ambrosia artemisiifolia)

Allergic rhinitis is a common health problem in both children and adults. The number of patients allergic to ragweed (Ambrosia artemisiifolia) is on the rise throughout Europe, having a significant negative impact on the patients' and their family's quality of life. Allergen-specific immunotherapy (AIT) has disease-modifying effects and can induce immune tolerance to allergens. Both subcutaneous immunotherapy and sublingual immunotherapy with ragweed extracts/preparations have clear positive clinical efficacy, especially over pharmacological treatment, even years after the treatment has ended. AIT also has very good safety profiles with extremely rare side effects, and the extracts/preparations used in AIT are commonly well tolerated by patients. However, patient adherence to treatment with AIT seems to be quite low, mostly due to the fact that treatment with AIT is relatively time-demanding and, moreover, due to patients not receiving adequate information and education about the treatment before it starts. AIT is undergoing innovations and improvements in clinical efficacy, safety and patient adherence, especially with new approaches using new adjuvants, recombinant or modified allergens, synthetic peptides, novel routes of administration (epidermal or intralymphatic), and new protocols, which might make AIT more acceptable for a wider range of patients and novel indications. Patient education and support (eg, recall systems) is one of the most important goals for AIT in the future, to further enhance treatment success.

Current Evidence on Safety and Practical Considerations for Administration of Sublingual Allergen Immunotherapy (SLIT) in the United States

Liquid sublingual allergen immunotherapy (SLIT) has been used off-label for decades, and Food and Drug Administration (FDA)-approved grass and ragweed SLIT tablets have been available in the United States since 2014. Potentially life-threatening events from SLIT do occur, although they appear to be very rare, especially for FDA-approved products. Practice guidelines that incorporate safety precautions regarding the use of SLIT in the United States are needed. This clinical commentary attempts to address unresolved issues including controversy regarding the FDA mandate for the prescription of epinephrine autoinjectors for patients on SLIT; how to approach polysensitized patients; optimal timing and duration of SLIT administration; how to address gaps in therapy; whether antihistamines can prevent local reactions, if certain patient populations (such as persistent asthmatics) should not receive SLIT; and when to instruct patients to self-administer epinephrine. Key points are that physicians should focus on educating patients regarding: (1) when not to administer SLIT; (2) how to recognize a potentially serious allergic reaction to SLIT; and (3) when to administer epinephrine and seek emergency care.

Evidence in immunotherapy for paediatric respiratory allergy: Advances and recommendations

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

Clinical contraindications to allergen immunotherapy: an EAACI position paper

Clinical indications for allergen immunotherapy (AIT) in respiratory and Hymenoptera venom allergy are well established; however, clinical contraindications to AIT are not always well documented. There are some discrepancies when classifying clinical contraindications for different forms of AIT as 'absolute' or 'relative'. EAACI Task Force on 'Contraindications to AIT' was created to evaluate and review current literature on clinical contraindications, and to update recommendations for both sublingual and subcutaneous AIT for respiratory and venom immunotherapy. An extensive review of the literature was performed on the use of AIT in asthma, autoimmune disorders, malignant neoplasias, cardiovascular diseases, acquired immunodeficiencies and other chronic diseases (including mental disorders), in patients treated with β-blockers, ACE inhibitors or monoamine oxidase inhibitors, in children under 5 years of age, during pregnancy and in patients with poor compliance. Each topic was addressed by the following three questions: (1) Are there any negative effects of AIT on this concomitant condition/disease? (2) Are more frequent or more severe AIT-related side-effects expected? and (3) Is AIT expected to be less efficacious? The evidence, for the evaluation of these clinical conditions as contraindications, was limited, and most of the conclusions were based on case reports. Based on an extended literature research, recommendations for each medical condition assessed are provided. The final decision on the administration of AIT should be based on individual evaluation of any medical condition and a risk/benefit assessment for each patient.

Histamine type 2 receptor expression on peripheral blood regulatory lymphocytes in patients with allergic rhinitis treated with specific immunotherapy

BACKGROUND

Both histamine H1- and H2-receptors (H2R) were found on regulatory T (Treg) cells; however, there is a paucity of information regarding the role of H2R in Treg function. This study aimed to investigate the effects of natural allergen stimulation and specific immunotherapy (SIT) on H2R expression in Treg cells in patients with allergic rhinitis (AR).

METHODS

In this prospective, double-blind, placebo-controlled study 41 patients with AR were screened for 1 year and treated with SIT (n = 21) or placebo (n = 20) for the next 2 years. Fifteen healthy subjects were included as a control. Subsets of Treg cells that expressed H2R were assessed annually in the blood by flow cytometry: before, at the height of the pollen season, and after, at the end of the pollen season. In addition, total nasal symptom score, the use of rescue medication, and nasal eosinophilia were evaluated.

RESULTS

Treg cells of AR patients slightly up-regulate H2R out of the pollen season. Natural allergen stimulation results in prompt up-regulation of H2R within these cells. SIT significantly decreased the number of Treg cells with increased expression of H2R in the blood exclusively at the height of pollen season, which, however, had no impact on the expression of H2R in Treg cells. SIT improved significantly the symptom score, rescue medication use, and decreased nasal eosinophilia.

CONCLUSION

Natural pollen exposure results in up-regulation of H2R in Treg cells. Immunotherapy might transiently decrease the number of Treg-H2R(+) cells in the blood, which may be associated with their migration to the peripheral tissues. This study was part of the clinical trial registered in www.clinicaltrials.gov.

Immunotherapy in all aspects

Allergen immunotherapy is a form of long-term treatment that decreases symptoms for many people with allergic rhinitis, allergic asthma, conjunctivitis (eye allergy) or stinging insect allergy. In this review, we presented the important topics in immunotherapy. The important aspects of immunotherapy are considered to be "Immunologıcal responses to immunotherapy"; "The principal types of immunotherapy"; "Effectiveness"; "Indications"; "Contraindications"; "Allergen immunotherapy in children"; "Safety"; and "Anaphylactic reactions after immunotherapy". The principal types of immunotherapy are subcutaneous immunotherapy (SCIT) and sublingual immunotherapy. Both of them can be used in indicated cases. When using SCIT, physicians must be more careful because of reported rare fatal cases. The risks and benefits of continuing allergen immunotherapy in patients who have experienced severe systemic reactions should be carefully considered.

Systemic reactions to inhalant immunotherapy using 1:1 target dosing

BACKGROUND

The 2007 immunotherapy practice parameters advocate maintenance dosing at 1:1 (1:20 maintenance concentrate). There is limited literature exploring the effect of 1:1 dosing on the rate of systemic reactions to subcutaneous immunotherapy (SRITs).

OBJECTIVE

To investigate the effects of 1:1 dosing on SRITs in a large, academic practice.

METHODS

We conducted a retrospective cohort study of all nonvenom and noncluster SRITs that occurred between 2005 and 2011. SRITs that occurred from August 2008 through December 2011, postparameter dosing (post-PD) was initiated, were compared to SRITs that occurred from January 2005 to July 2008 with preparameter dosing (pre-PD) using 1:50 as a maintenance concentrate.

RESULTS

A total of 269 SRITs occurred in a 7-year period. Significantly more post-PD SRITs (131 of 38,548 injections) occurred than pre-PD SRITs (132 of 52,833 injections) (0.34% vs 0.25%, P = .01). However, when excluding 44 SRITs that occurred in established pre-PD patients transitioned to post-PD, there was no significant difference in SRIT rate (0.25% vs 0.22%), World Allergy Organization (WAO) grade, or SRIT time to onset. Nonred (non-1:1) vials accounted for a significantly larger proportion of all post-PD SRITs compared with all pre-PD SRITs (50.7% vs 31.1%, adjusted P = .009). Prior SRITs were reported less frequently among persons with post-PD SRITs (29.2% vs 70.8%, adjusted P = .009). In an adjusted logistic regression model, male sex (odds ratio, 7.9; 95% CI, 2.4-26) and longer time to reaction onset (odds ratio, 0.94; 95% CI, 0.89-0.99) were associated with higher WAO severity grade reactions.

CONCLUSION

Pre-PD vs post-PD SRIT rates were not significantly different, adjusting for patients transitioned from established pre-PD to post-PD. This finding suggests that post-PD is as safe as pre-PD. Male sex and faster time to reaction onset were associated with higher WAO grade reactions.

Guideline on allergen-specific immunotherapy in IgE-mediated allergic diseases: S2k Guideline of the German Society for Allergology and Clinical Immunology (DGAKI), the Society for Pediatric Allergy and Environmental Medicine (GPA), the Medical Association of German Allergologists (AeDA), the Austrian Society for Allergy and Immunology (ÖGAI), the Swiss Society for Allergy and Immunology (SGAI), the German Society of Dermatology (DDG), the German Society of Oto- Rhino-Laryngology, Head and Neck Surgery (DGHNO-KHC), the German Society of Pediatrics and Adolescent Medicine (DGKJ), the Society for Pediatric Pneumology (GPP), the German Respiratory Society (DGP), the German Association of ENT Surgeons (BV-HNO), the Professional Federation of Paediatricians and Youth Doctors (BVKJ), the Federal Association of Pulmonologists (BDP) and the German Dermatologists Association (BVDD)

The present guideline (S2k) on allergen-specific immunotherapy (AIT) was established by the German, Austrian and Swiss professional associations for allergy in consensus with the scientific specialist societies and professional associations in the fields of otolaryngology, dermatology and venereology, pediatric and adolescent medicine, pneumology as well as a German patient organization (German Allergy and Asthma Association; Deutscher Allergie- und Asthmabund, DAAB) according to the criteria of the Association of the Scientific Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF). AIT is a therapy with disease-modifying effects. By administering allergen extracts, specific blocking antibodies, toler-ance-inducing cells and mediators are activated. These prevent further exacerbation of the allergen-triggered immune response, block the specific immune response and attenuate the inflammatory response in tissue. Products for SCIT or SLIT cannot be compared at present due to their heterogeneous composition, nor can allergen concentrations given by different manufacturers be compared meaningfully due to the varying methods used to measure their active ingredients. Non-modified allergens are used for SCIT in the form of aqueous or physically adsorbed (depot) extracts, as well as chemically modified allergens (allergoids) as depot extracts. Allergen extracts for SLIT are used in the form of aqueous solutions or tablets. The clinical efficacy of AIT is measured using various scores as primary and secondary study endpoints. The EMA stipulates combined symptom and medication scores as primary endpoint. A harmonization of clinical endpoints, e. g., by using the combined symptom and medication scores (CSMS) recommended by the EAACI, is desirable in the future in order to permit the comparison of results from different studies. The current CONSORT recommendations from the ARIA/GA2LEN group specify standards for the evaluation, presentation and publication of study results. According to the Therapy allergen ordinance (TAV), preparations containing common allergen sources (pollen from grasses, birch, alder, hazel, house dust mites, as well as bee and wasp venom) need a marketing authorization in Germany. During the marketing authorization process, these preparations are examined regarding quality, safety and efficacy. In the opinion of the authors, authorized allergen preparations with documented efficacy and safety, or preparations tradeable under the TAV for which efficacy and safety have already been documented in clinical trials meeting WAO or EMA standards, should be preferentially used. Individual formulations (NPP) enable the prescription of rare allergen sources (e.g., pollen from ash, mugwort or ambrosia, mold Alternaria, animal allergens) for specific immunotherapy. Mixing these allergens with TAV allergens is not permitted. Allergic rhinitis and its associated co-morbidities (e. g., bronchial asthma) generate substantial direct and indirect costs. Treatment options, in particular AIT, are therefore evaluated using cost-benefit and cost-effectiveness analyses. From a long-term perspective, AIT is considered to be significantly more cost effective in allergic rhinitis and allergic asthma than pharmacotherapy, but is heavily dependent on patient compliance. Meta-analyses provide unequivocal evidence of the efficacy of SCIT and SLIT for certain allergen sources and age groups. Data from controlled studies differ in terms of scope, quality and dosing regimens and require product-specific evaluation. Therefore, evaluating individual preparations according to clearly defined criteria is recommended. A broad transfer of the efficacy of certain preparations to all preparations administered in the same way is not endorsed. The website of the German Society for Allergology and Clinical Immunology (www.dgaki.de/leitlinien/s2k-leitlinie-sit; DGAKI: Deutsche Gesellschaft für Allergologie und klinische Immunologie) provides tables with specific information on available products for AIT in Germany, Switzerland and Austria. The tables contain the number of clinical studies per product in adults and children, the year of market authorization, underlying scoring systems, number of randomized and analyzed subjects and the method of evaluation (ITT, FAS, PP), separately given for grass pollen, birch pollen and house dust mite allergens, and the status of approval for the conduct of clinical studies with these products. Strong evidence of the efficacy of SCIT in pollen allergy-induced allergic rhinoconjunctivitis in adulthood is well-documented in numerous trials and, in childhood and adolescence, in a few trials. Efficacy in house dust mite allergy is documented by a number of controlled trials in adults and few controlled trials in children. Only a few controlled trials, independent of age, are available for mold allergy (in particular Alternaria). With regard to animal dander allergies (primarily to cat allergens), only small studies, some with methodological deficiencies are available. Only a moderate and inconsistent therapeutic effect in atopic dermatitis has been observed in the quite heterogeneous studies conducted to date. SCIT has been well investigated for individual preparations in controlled bronchial asthma as defined by the Global Initiative for Asthma (GINA) 2007 and intermittent and mild persistent asthma (GINA 2005) and it is recommended as a treatment option, in addition to allergen avoidance and pharmacotherapy, provided there is a clear causal link between respiratory symptoms and the relevant allergen. The efficacy of SLIT in grass pollen-induced allergic rhinoconjunctivitis is extensively documented in adults and children, whilst its efficacy in tree pollen allergy has only been shown in adults. New controlled trials (some with high patient numbers) on house dust mite allergy provide evidence of efficacy of SLIT in adults. Compared with allergic rhinoconjunctivitis, there are only few studies on the efficacy of SLIT in allergic asthma. In this context, newer studies show an efficacy for SLIT on asthma symptoms in the subgroup of grass pollen allergic children, adolescents and adults with asthma and efficacy in primary house dust mite allergy-induced asthma in adolescents aged from 14 years and in adults. Aspects of secondary prevention, in particular the reduction of new sensitizations and reduced asthma risk, are important rationales for choosing to initiate treatment early in childhood and adolescence. In this context, those products for which the appropriate effects have been demonstrated should be considered. SCIT or SLIT with pollen or mite allergens can be performed in patients with allergic rhinoconjunctivitis using allergen extracts that have been proven to be effective in at least one double-blind placebo-controlled (DBPC) study. At present, clinical trials are underway for the indication in asthma due to house dust mite allergy, some of the results of which have already been published, whilst others are still awaited (see the DGAKI table "Approved/potentially completed studies" via www.dgaki.de/Leitlinien/s2k-Leitlinie-sit (according to www.clinicaltrialsregister.eu)). When establishing the indication for AIT, factors that favour clinical efficacy should be taken into consideration. Differences between SCIT and SLIT are to be considered primarily in terms of contraindications. In individual cases, AIT may be justifiably indicated despite the presence of contraindications. SCIT injections and the initiation of SLIT are performed by a physician experienced in this type of treatment and who is able to administer emergency treatment in the case of an allergic reaction. Patients must be fully informed about the procedure and risks of possible adverse events, and the details of this process must be documented (see "Treatment information sheet"; available as a handout via www.dgaki.de/Leitlinien/s2k-Leitlinie-sit). Treatment should be performed according to the manufacturer's product information leaflet. In cases where AIT is to be performed or continued by a different physician to the one who established the indication, close cooperation is required in order to ensure that treatment is implemented consistently and at low risk. In general, it is recommended that SCIT and SLIT should only be performed using preparations for which adequate proof of efficacy is available from clinical trials. Treatment adherence among AIT patients is lower than assumed by physicians, irrespective of the form of administration. Clearly, adherence is of vital importance for treatment success. Improving AIT adherence is one of the most important future goals, in order to ensure efficacy of the therapy. Severe, potentially life-threatening systemic reactions during SCIT are possible, but - providing all safety measures are adhered to - these events are very rare. Most adverse events are mild to moderate and can be treated well. Dose-dependent adverse local reactions occur frequently in the mouth and throat in SLIT. Systemic reactions have been described in SLIT, but are seen far less often than with SCIT. In terms of anaphylaxis and other severe systemic reactions, SLIT has a better safety profile than SCIT. The risk and effects of adverse systemic reactions in the setting of AIT can be effectively reduced by training of personnel, adhering to safety standards and prompt use of emergency measures, including early administration of i. m. epinephrine. Details on the acute management of anaphylactic reactions can be found in the current S2 guideline on anaphylaxis issued by the AWMF (S2-AWMF-LL Registry Number 061-025). AIT is undergoing some innovative developments in many areas (e. g., allergen characterization, new administration routes, adjuvants, faster and safer dose escalation protocols), some of which are already being investigated in clinical trials. Cite this as Pfaar O, Bachert C, Bufe A, Buhl R, Ebner C, Eng P, Friedrichs F, Fuchs T, Hamelmann E, Hartwig-Bade D, Hering T, Huttegger I, Jung K, Klimek L, Kopp MV, Merk H, Rabe U, Saloga J, Schmid-Grendelmeier P, Schuster A, Schwerk N, Sitter H, Umpfenbach U, Wedi B, Wöhrl S, Worm M, Kleine-Tebbe J. Guideline on allergen-specific immunotherapy in IgE-mediated allergic diseases - S2k Guideline of the German Society for Allergology and Clinical Immunology (DGAKI), the Society for Pediatric Allergy and Environmental Medicine (GPA), the Medical Association of German Allergologists (AeDA), the Austrian Society for Allergy and Immunology (ÖGAI), the Swiss Society for Allergy and Immunology (SGAI), the German Society of Dermatology (DDG), the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery (DGHNO-KHC), the German Society of Pediatrics and Adolescent Medicine (DGKJ), the Society for Pediatric Pneumology (GPP), the German Respiratory Society (DGP), the German Association of ENT Surgeons (BV-HNO), the Professional Federation of Paediatricians and Youth Doctors (BVKJ), the Federal Association of Pulmonologists (BDP) and the German Dermatologists Association (BVDD). Allergo J Int 2014;23:282-319.

Accelerated immunotherapy schedules

Rush and cluster immunotherapy schedules are accelerated immunotherapy build-up schedules. A cluster immunotherapy schedule involves the patient receiving several allergen injections (generally 2-4) sequentially in a single day of treatment on nonconsecutive days. The maintenance dose is generally reached in 4-8 weeks. In rush immunotherapy protocols, higher doses are administered at 15- to 60-min intervals over a 1- to 3-day period until the maintenance dose is achieved. This review will serve as an update for accelerated immunotherapy schedules. The review will include recent investigations demonstrating the safety of cluster schedules in atopic dermatitis, pediatric patients, and inhalant allergen mixtures and an accelerated protocol utilizing an infusion pump for allergen delivery. There has also been further elucidation on the immunological changes which occur during accelerated immunotherapy. Finally, new studies analyzing systemic reaction risk factors are discussed.

A 1-day imported fire ant rush immunotherapy schedule with and without premedication

BACKGROUND

Rush immunotherapy (RIT) schedules can expedite protection in individuals sensitive to imported fire ant (IFA) stings.

OBJECTIVE

To evaluate the safety and efficacy of 1-day RIT with IFA whole body extract (WBE) and determine the benefit of premedication with antihistamines and prednisone.

METHODS

Patients with systemic reactions to IFAs and evidence of specific IgE by skin test or serologic test started a 1-day RIT protocol without premedication. The 1-day RIT protocol consisted of a total of 10 injections every 30 to 60 minutes to achieve a 0.3-mL 1:100 (wt/vol) dose. A higher systemic reaction rate (SRR) prompted protocol revision to include a 3-day course of oral 20 mg of prednisone twice daily, 150 mg of ranitidine, and 10 mg of loratadine started 2 days before the 1-day RIT. Patients returned on days 8 and 15 to receive a 0.5 mL 1:100 (wt/vol) maintenance injection. The effectiveness of the RIT was evaluated with a sting challenge on approximately day 22.

RESULTS

Eighty of the 96 patients enrolled initiated the 1-day RIT. The first nonpremedicated group exhibited a SRR of 24.3% (9 of 37 patients), whereas the revised premedicated group had a SRR of 9.5% (4 of 42 patients; P = .07). The most severe reaction during RIT included dizziness, angioedema, and urticaria. Sting challenges on 53 patients resulted in 1 mild rhinitis reaction (efficacy, 98.1%).

CONCLUSION

One-day RIT with IFA WBE for IFA hypersensitivity is efficacious. Although there was a trend with premedications to reduce SRRs during the RIT, safety data with premedication require confirmation in a larger trial.

AAAAI and ACAAI surveillance study of subcutaneous immunotherapy, Year 3: what practices modify the risk of systemic reactions?

OBJECTIVE

To define the incidence of and clinical practices associated with subcutaneous immunotherapy (SCIT)-related systemic reactions (SRs).

METHODS

From 2008-2011, American Academy of Allergy, Asthma & Immunology and American College of Allergy, Asthma & Immunology members completed an annual survey of SCIT-related SRs of varying severity (with grade 1 indicating mild; grade 2, moderate; and grade 3, severe anaphylaxis). From 2010-2011 (year 3) data were collected regarding SCIT-related procedures, including screening of patients with asthma, dose adjustment during peak pollen seasons, build-up regimens (conventional, cluster, or rush), and premedication.

RESULTS

No fatal reactions were directly or indirectly reported from 2008-2011. The SR rates were similar for all 3 years (0.1% of injection visits; 83% of practices), as were severity grades. On average, for all 3 years, there were 7.1 grade 1, 2.6 grade 2, and 0.4 grade 3 SRs per 10,000 injection visits. Screening for worsening asthma symptoms was highly prevalent (86% always screened). Practices that always reduced doses during peak pollen season were significantly less likely to report grade 2 or 3 SRs (44% vs 65%; P = .04). Cluster and rush build-up were associated with significantly more SRs (P < .001). Practices that premedicated were significantly more likely to report grade 2 and 3 SRs (P < .01).

CONCLUSION

Fatal reactions to SCIT appear to be declining, possibly related to almost universal screening of asthmatic patients. Adjusting doses during the pollen season may be associated with decreased risk for severe SRs. Cluster and rush immunotherapy were associated with increased risk for SRs. Premedication by practices reporting SRs likely reflects past experience with SRs.

Subcutaneous allergen immunotherapy for allergic disease: examining efficacy, safety and cost-effectiveness of current and novel formulations

Subcutaneous immunotherapy (SCIT) is a unique therapy for allergic disease because it provides symptomatic relief while modifying the allergic disease by targeting the underlying immunological mechanism. Its efficacy and safety have been established in the treatment of asthma, allergic rhinitis/rhinoconjunctivitis and stinging insect hypersensitivity in numerous controlled clinical trials. This review evaluates a spectrum of clinical factors, ranging from efficacy to cost-effectiveness, which should be considered in evaluating SCIT. The evidence for SCIT safety and efficacy for these conditions is reviewed in an evaluation of the systematic reviews and meta-analyses. The evidence for the persistent and preventive effects of SCIT is also examined. An overview of the SCIT outcomes measures utilized in clinical trials is presented. The cost-effectiveness of SCIT compared with conventional medication treatment, novel indications and formulations for SCIT are also explored in this review.

Immunotherapy - Vaccines for allergic diseases

Allergic diseases are some of the most commonly encountered problems in clinical practice. Drugs such as corticosteroids and antihistamines can provide effective symptomatic relief, but do not alter the course of the disease. Specific immunotherapy (SIT) was first used to treat pollen allergy in 1911, and has since evolved into an effective treatment for allergic rhinitis and asthma. SIT has been shown in clinical studies to reduce symptoms and medication use in patients with allergic rhinitis and asthma. Recent studies also showed that the therapeutic benefit is long-lasting after the completion of three to five years of treatment. SIT can also effectively reduce the risk of developing asthma and new allergic sensitizations in children with allergic rhinitis.

Safety of allergen immunotherapy: a review of premedication and dose adjustment

From the first allergen immunotherapy proposed in the early 1900s to the present day, numerous studies have proven the efficacy of allergen immunotherapy for the treatment of allergic rhinitis, allergic conjunctivitis, allergic asthma and stinging insect hypersensitivity. The major risk, however small, with allergen immunotherapy is anaphylaxis. There has been considerable interest and debate regarding risk factors for immunotherapy reactions (local and systemic) and interventions to reduce the occurrence of these reactions. One of these interventions that is especially debated regards dose adjustment for various reasons, but in particular for local reactions. In this review, we discuss the safety of immunotherapy and provide a comprehensive review of the literature regarding immunotherapy schedules and doses.

[Pharmacoprophylaxis and co-medications in allergen-specific immunotherapy]

Drugs that are used in relation to allergen-specific immunotherapy (SIT) can be separated into pharmacoprophylaxis to avoid or decrease local and systemic adverse effects of SIT and in co-medications to treat other diseases. Regarding pharmacoprophylaxis, H1-antihistamines are able to reduce local and mild systemic, but not severe systemic side effects of SIT. H1-antihistamines do not attenuate the efficacy of SIT. Severe systemic side effects have been blocked in some cases with omalizumab; currently this agent can be used off-label during venom SIT. With regard to co-medication, the concomitant use of immunomodulating drugs during SIT must be individualized, if the effective profile and side effects of the immunomodulating drug are well-known and a negative effect on SIT is not likely. Recently approved immunosuppressive drugs and biologics are perceived critically due to their unpredictable immunologic effects. For forensic reasons cardioselective beta blockers should be discontinued although no data are available demonstrating adverse effects. If discontinuation is not justified and venom SIT is indicated, SIT can be performed while taking beta blockers. In contrast, ACE-inhibitors should always be stopped in patients with insect venom allergy.

How should allergists deal with local reactions to allergen immunotherapy?

Despite the well-known benefits of subcutaneous immunotherapy (SCIT), adverse reactions include both local reactions (LRs) and systemic reactions. An LR is a well-known adverse event associated with SCIT injections and is defined as any swelling located at or near the injection site following allergen injection. Concerns that LRs might predict systemic reactions have historically motivated allergists to dose adjust for LRs. More recent data have dispelled this notion, although many allergists continue to dose adjust for other reasons. This article discusses the historical response to LRs and dose adjustments and reviews the most recent literature addressing LRs to SCIT. Treatment options, although they are either unproven or not studied, are offered as an alternative to routine dose adjustments for LRs. Education remains the foundation of physician-patient communication concerning LRs.

Allergen immunotherapy: immunomodulatory treatment for allergic diseases

Allergen immunotherapy is currently the only immune-modifying treatment for allergic disease. At the present time it is indicated for the treatment of allergic rhinitis, asthma and venom hypersensitivity. Efficacy appears to be dose dependent, and the immunological mechanisms responsible for the clinical efficacy of immunotherapy are still being elucidated. Immunological changes associated with immunotherapy include induction of T regulatory cells, increase in allergen-specific immunoglobulin G4, increase in interleukin-10 production and downregulation of the T helper 2 response. The disadvantages of allergen immunotherapy include risk of adverse events and patient time and inconvenience. Risks of immunotherapy range from large local reactions to mild systemic reactions, such as rhinitis. Fatalities from immunotherapy injections have been reported at a rate of approximately one fatality per 2.5 million injections. Conventional subcutaneous immunotherapy build-up schedules involve administration of a single-dose increase each visit and it may take several months before a patient achieves the therapeutic maintenance dose. Accelerated schedules, such as rush and cluster, will allow the patient to achieve the maintenance dose sooner but there may be a greater risk of a systemic reaction. The current focus of immunotherapy research is to develop safer and more effective vaccines. Another approach to enhancing immunotherapy safety is through an alternative delivery method. Sublingual immunotherapy is clearly safer than subcutaneous immunotherapy, but further investigation is needed to determine optimal dose and appropriate patient selection.

[Allergen-specific Immunotherapy for children and adolescents - a review on available products in Austria]

A pediatric consensus report on allergen-specific immunotherapy for children and adolescents is presented for Austria. Products on the market in Austria are presented and categorised according to studies performed on the target population of children and adolescents, their effectiveness and indication. In general, more clinical studies on children and adolescents are mandatory for most of the available allergen-specific immunotherapeutics. In addition, the use of allergen-specific immunotherapy in general should be promoted as the exclusive treatment with long-lasting effects in type I allergies in particular in children.

A review of allergen-specific immunotherapy in human and veterinary medicine

This article reviews allergen-specific immunotherapy in human and veterinary medicine. Current hypotheses of possible mechanisms of actions are outlined. Indications, success rates, adverse effects and factors influencing outcome of therapy are discussed in humans, dogs, cats and horses.