Benefits of immunotherapy with a standardized Dermatophagoides pteronyssinus extract in asthmatic children: a three-year prospective study

Preventive allergen immunotherapy with inhalant allergens in children

The efficacy and safety of preventive allergen immunotherapy (pAIT) in children are currently under investigation. Here, we provide an overview of pAIT with respiratory allergens concerning the prevention of new sensitizations, allergic disease onset and progression as well as further immunomodulatory effects. Three databases were searched for clinical pAIT studies in children. Selected publications were reviewed for preventive outcomes according to prevention level (primary, secondary, and tertiary), allergen type, administration route, dose, and treatment duration. The primary prevention approach appears safe but showed no allergen-specific effect on new sensitizations. Secondary prevention seems feasible and may induce regulatory T cell-mediated immunotolerance. The number of studies at these prevention levels is limited. Tertiary prevention with grass and/or tree pollen-based pAIT has shown efficacy in preventing disease progression from allergic rhinitis/conjunctivitis to asthma. Data on tertiary pAIT with house dust mites and other allergen types are inconclusive. Subcutaneous and sublingual routes appear similarly effective, but head-to-head comparative paediatric studies are scarce. Additionally, there are fewer placebo-controlled studies. Nevertheless, immunomodulatory outcomes of pAIT are encouraging. Currently, limited but favourably suggestive evidence is available for preventing respiratory allergic diseases in children by pAIT. Primary and secondary prevention have potential and warrant further investigation through well-designed studies.

Allergen Immunotherapy for Asthma

Allergen immunotherapy is a disease-modifying treatment for IgE-mediated allergies reducing disease burden and symptoms in patients with allergic rhinitis, with or without asthma. The growing evidence that allergen immunotherapy also has the potential to facilitate achieving asthma control in patients with allergic asthma resulted in its acknowledgment by international bodies (Global Initiative for Asthma and European Academy of Allergy and Clinical Immunology) as add-on treatment for mild/moderate asthma. Although there have been promising developments in biomarkers for patient selection and for allergen immunotherapy efficacy evaluation in patients with asthma, a lot more data are still required.

Prevention Is Better than Cure: Impact of Allergen Immunotherapy on the Progression of Airway Disease

Allergen immunotherapy is highly effective for seasonal pollinosis. Three years of treatment results in long-term efficacy. This disease modification is accompanied by downregulation of allergen-specific Th2 responses and the induction of persistent specific IgG- and IgA-associated IgE-blocking activity. In children with seasonal rhinitis, both subcutaneous and sublingual pollen immunotherapy have been shown to reduce the development of asthma symptoms and asthma medication requirements. House dust mite tablet allergen immunotherapy has been shown to be effective for perennial mite-driven rhinitis in adults and children and may suppress asthma exacerbations, whereas its long-term efficacy has yet to be explored. The success of primary prevention of peanut allergy in childhood by introduction of peanut into the diet during infancy provides a strong rationale to explore whether primary prevention of inhalant allergies and asthma may also be possible. House dust mite allergy is a major risk factor for developing asthma. Preliminary data in at-risk children suggest that sublingual house dust mite immunotherapy initiated during infancy could reduce the onset of multiple allergen sensitizations and prevent the development of asthma at age 6 years. This possibility should now be explored in an adequately powered, prospectively randomized controlled trial.

Prevelance of Common Aeroallergens in Allergic Rhinitis and its Correlation with Bronchial Asthma: A Study on 798 Patients by Skin Prick Test

Allergic rhinitis affects 30% of the Indian population (Dey et al. in Int Arch Allergy Immunol 178:60-65, 2019). Patients can be sensitive to single or multiple allergens. Polysensitization is more common (Bousquet et al. in Ann Epidemiol 20:797-803, 2010; Arbes et al. in J Allergy Clin Immunol 116:377-383, 2005). Sensitization to multiple allergens may have a role in the severity and the association of Asthma in such patients. A total of 798 patients with allergic rhinitis (SFAR ≥ 7) were included. Disease severity and associated symptoms were evaluated using questionnaire. Each patient underwent a Skin prick test with an allergen panel of 35 allergens each (Annesi-Maesano et al. in Allergy 57:107-114, 2002) and the results were evaluated to study the association of asthma and severity of Allergic rhinitis. Data consisting of 389 (48.7%) males and 409 (51.3%) females were assessed. A total of 82.2% of the study population of symptomatic patients were sensitized to at least one of the allergens. Seventy patients (8.78%) had associated asthma. Forty-four patients were polysensitized and fifteen were mono sensitized. Among polysensitized patients, 36 patients had sensitization to at least 6 different allergens. Dermatophagoides pteronyssinus was the most common allergen among asthma patients. This study provides a thorough knowledge of locally prevalent aeroallergens which is essential for the prompt diagnosis and treatment of allergic patients. Skin prick test can be a non-invasive vital tool in analyzing patterns of allergen exposure, the prevalence of allergen, sensitizing potential of different allergens in that specific geographic area.

Efficacy and safety of subcutaneous immunotherapy in asthmatic children allergic to house dust mite: a meta-analysis and systematic review

Background

Subcutaneous immunotherapy (SCIT) has been proved to be effective and safe in adult asthma. But it is still controversial in children.

Object

To evaluate the efficacy and safety of SCIT in asthmatic children with allergy to house dust mite.

Method

We searched the databases of Cochrane Library, EMBASE and MEDLINE (from 1 January 1990 to 1 December 2022). Two reviewers independently screened studies, extracted data and critically appraised the risk of bias. We used the Revman 5 to synthesize the effect sizes.

Results

We finally selected 38 eligible studies including 21 randomized controlled trials to evaluate the efficacy and safety of SCIT and 17 observational studies to assess the safety. The results revealed that short-term asthma symptom scores were declined with a standardized mean difference (SMD) of -1.19 (95% CI: -1.87, -0.50) in 12 researches with high heterogeneity. Short-term asthma medication scores were decreased with SMD -1.04 (95% CI: -1.54, -0.54) in 12 heterogeneous researches. One study showed no significant reduction in combined symptom and medication scores without providing details. No studies we reviewed reported long-term efficacy. SCIT resulted in an obviously increased risk of adverse reactions compared with placebo. For secondary outcomes, SCIT improved life quality and reduced the numbers of annual asthma attacks and allergen-specific airway hyperreactivity, but without significant improvement in pulmonary function, asthma control or hospitalization.

Conclusions

SCIT can reduce the short-term symptom scores and medication scores regardless of different treatment duration or mono/polysensitization, but with an increased incidence of local and systemic adverse effects. Further studies on pediatric asthma are needed to evaluate the long-term efficacy, and clarify the effectiveness of SCIT in specific population using mix allergen extracts or with severe asthma. Overall, it is recommended for children with mild-moderate HDM-driven allergic asthma.

Immunotherapy for Asthma

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

Does allergen immunotherapy for allergic rhinitis prevent asthma?

Asthma and allergic rhinitis (AR) have overlapping clinical and pathologic features, sustained by an underlying T helper 2 bias, resulting in airway inflammation that extends from the nose to the lung. Children who are monosensitized often develop polysensitization over time, and they are at high risk of developing asthma. The effect of allergen immunotherapy (AIT) is allergen specific, resulting in symptom improvement and reduction in medication requirement. It is the only known treatment that alters the natural history of allergic disease and induces long-term remission. A bystander or allergen-nonspecific effect of AIT has also been proposed-that AIT to 1 allergen might reduce the risk of development of sensitization to other allergens. Furthermore, several observational studies and clinical trials, in seasonal (pollen) and perennial (house dust mite) AR, have investigated a protective effect of AIT to prevent asthma. The overall evidence favors an asthma preventive effect of AIT in AR to grass and birch tree pollen. Fewer studies have investigated the use of AIT in children with perennial AR due to house dust mite allergy to prevent asthma, and the results are less convincing. The use of AIT to reduce the risk of progression to asthma, in children with AR, potentially has high impact, and it will make AIT more attractive and cost-effective. However, most studies have been of small sample size or of poor design, using different allergens and AIT methodology, making it challenging to draw firm conclusions. There is a need to do adequately powered studies with optimal design and assess cost-effectiveness of this strategy.

A Real-World Effectiveness of Subcutaneous Immunotherapy on the Cost of Medication, Allergic Rhinitis, and Asthma Exacerbations, as well as Upper Respiratory Tract Infection in Subjects with Allergic Rhinitis with or without Asthma: A Retrospective Pilot Study

Background and Objectives: Real-world studies are limited regarding the effectiveness of SCIT on allergic rhinitis (AR) with and without asthma and the cost of medication in Thailand. Moreover, limited data exist regarding the effectiveness of SCIT on worldwide upper respiratory tract infection (URTI). Therefore, the objective of this study was to compare the medication costs, rate of AR and asthma exacerbations, and rate of URTI in AR with or without asthma subjects before and during three years after receiving the maintenance phase of SCIT, compared with a standard usual care (SUC) group. Materials and Methods: A real-world retrospective study was conducted in AR subjects with or without asthma. From January 2001 to December 2018, 24 subjects with or without asthma received SCIT added to SUC, and 16 subjects were treated with SUC only at the Allergy and Chest Clinic of Chiang Mai Ram Hospital, Chiang Mai, Thailand. The cost of medication was recorded. AR and asthma exacerbations and URTI events were also collected. Results: From between-group comparisons, the cost of medication (THB) in the SCIT group at the one-, two-, and three-year follow up was significantly lower (587.4 (348.3–1374.6) vs. 1562.4 (1315.1–1857.3), p < 0.001, 501.2 (302.9–839.0) vs. 1728.3 (1190.0–2236.1), p < 0.001, and 372.4 (284.8–752.4) vs. 1500.3 (1217.9–1748.9), p < 0.001, respectively)), and AR and asthma exacerbations were significantly reduced at the three-year follow-up. From within-group comparisons, the cost of medication (THB) and AR and asthma exacerbations were significantly lower in the SCIT group at the one-, two-, and three-year follow-up. The URTI event was significantly reduced in the SCIT group at the two- and three-year follow-up. Conclusions: SCIT in subjects with AR with or without asthma was associated with a significantly reduced cost of medication, rates of AR and asthma exacerbations, and URTI events in the long term.

Allergic Endotypes and Phenotypes of Asthma

Allergic asthma is defined as asthma associated with sensitization to aeroallergens, which leads to asthma symptoms and airway inflammation. Allergic asthma is the most common asthma phenotype. The onset of allergic asthma is most often in childhood and is usually accompanied by other comorbidities including atopic dermatitis and allergic rhinitis. It is often persistent although there is a wide variation in disease severity. It is a T_H2-driven process. Biomarkers have been identified to distinguish patients with allergic asthma, particularly serum IgE levels, tests to indicate sensitization to aeroallergens such as specific IgE or skin prick test positivity, blood and sputum eosinophil levels, fraction of exhaled nitric oxide, and periostin. Treatments for allergic asthma include environmental control measures, allergen immunotherapy, and glucocorticoids. Biologics, targeting the T_H2 pathway, have been shown to be effective in the treatment of allergic asthma.

A randomized trial of subcutaneous allergy immunotherapy in inner-city children with asthma less than 4 years of age

BACKGROUND

Allergic sensitization to environmental allergens in the first years of life is a strong predictor of asthma morbidity in children. Allergy immunotherapy can improve asthma and allergy outcomes, but its efficacy in inner-city, atopic children of less than 4 years of age with recurrent wheezing has not yet been established.

OBJECTIVE

To determine whether subcutaneous allergy immunotherapy improves asthma in a population of US inner-city children when started at less than 4 years of age.

METHODS

In a randomized controlled, open-label phase I-II single-center trial in the Bronx, New York, 58 children with recurrent wheezing or physician-diagnosed asthma were randomized to receive asthma standard of care treatment with or without a 3-year course of multiple allergen subcutaneous immunotherapy.

RESULTS

A total of 23 children in the control group and 27 children in the immunotherapy group began the study. A total of 20 of 27 children commencing immunotherapy completed at least 2 years of immunotherapy. There was no difference in asthma medication and symptom scores between the treatment or control groups over time. Similarly, naso-ocular symptoms and allergy medication use were similar in both groups over time. Nevertheless, asthma-related quality of life improved in the immunotherapy group compared with the control group (P = .03).

CONCLUSION

With the exception of asthma-related quality of life, allergy immunotherapy was ineffective in improving asthma outcomes in this population of inner-city children of less than 4 years of age. These findings suggest that the effects of allergy immunotherapy depend on population-specific factors and highlight the importance of precise predictors of immunotherapy efficacy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01028560.

Managing Asthma in Adolescents and Adults: 2020 Asthma Guideline Update From the National Asthma Education and Prevention Program

IMPORTANCE

Asthma is a major public health problem worldwide and is associated with excess morbidity, mortality, and economic costs associated with lost productivity. The National Asthma Education and Prevention Program has released the 2020 Asthma Guideline Update with updated evidence-based recommendations for treatment of patients with asthma.

OBJECTIVE

To report updated recommendations for 6 topics for clinical management of adolescents and adults with asthma: (1) intermittent inhaled corticosteroids (ICSs); (2) add-on long-acting muscarinic antagonists; (3) fractional exhaled nitric oxide; (4) indoor allergen mitigation; (5) immunotherapy; and (6) bronchial thermoplasty.

EVIDENCE REVIEW

The National Heart, Lung, and Blood Advisory Council chose 6 topics to update the 2007 asthma guidelines based on results from a 2014 needs assessment. The Agency for Healthcare Research and Quality conducted systematic reviews of these 6 topics based on literature searches up to March-April 2017. Reviews were updated through October 2018 and used by an expert panel (n = 19) that included asthma content experts, primary care clinicians, dissemination and implementation experts, and health policy experts to develop 19 new recommendations using the GRADE method. The 17 recommendations for individuals aged 12 years or older are reported in this Special Communication.

FINDINGS

From 20 572 identified references, 475 were included in the 6 systematic reviews to form the evidence basis for these recommendations. Compared with the 2007 guideline, there was no recommended change in step 1 (intermittent asthma) therapy (as-needed short-acting β2-agonists [SABAs] for rescue therapy). In step 2 (mild persistent asthma), either daily low-dose ICS plus as-needed SABA therapy or as-needed concomitant ICS and SABA therapy are recommended. Formoterol in combination with an ICS in a single inhaler (single maintenance and reliever therapy) is recommended as the preferred therapy for moderate persistent asthma in step 3 (low-dose ICS-formoterol therapy) and step 4 (medium-dose ICS-formoterol therapy) for both daily and as-needed therapy. A short-term increase in the ICS dose alone for worsening of asthma symptoms is not recommended. Add-on long-acting muscarinic antagonists are recommended in individuals whose asthma is not controlled by ICS-formoterol therapy for step 5 (moderate-severe persistent asthma). Fractional exhaled nitric oxide testing is recommended to assist in diagnosis and monitoring of symptoms, but not alone to diagnose or monitor asthma. Allergen mitigation is recommended only in individuals with exposure and relevant sensitivity or symptoms. When used, allergen mitigation should be allergen specific and include multiple allergen-specific mitigation strategies. Subcutaneous immunotherapy is recommended as an adjunct to standard pharmacotherapy for individuals with symptoms and sensitization to specific allergens. Sublingual immunotherapy is not recommended specifically for asthma. Bronchial thermoplasty is not recommended as part of standard care; if used, it should be part of an ongoing research effort.

CONCLUSIONS AND RELEVANCE

Asthma is a common disease with substantial human and economic costs globally. Although there is no cure or established means of prevention, effective treatment is available. Use of the recommendations in the 2020 Asthma Guideline Update should improve the health of individuals with asthma.

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

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

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.

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.

Molecular diagnosis for allergen immunotherapy

The extensive use of allergen molecules in birth cohort studies revealed that atopic sensitization is a sequential IgE response to distinct non-cross-reacting molecules from the same allergenic source (ie, molecular spreading), starting with an initiator molecule. This phenomenon reaches different degrees of progression (monomolecular, oligomolecular, and polymolecular) according to the individual atopic propensity and allergen exposure, thus producing an extreme heterogeneity of IgE sensitization profiles in patient populations. In patients with allergic rhinitis, the broader the IgE molecular sensitization profile, the greater is the risk of asthma and other allergic comorbidities, such as oral allergy syndrome. Hence it has been proposed to anticipate immunologic intervention at disease onset (early allergen immunotherapy) or even earlier during the preclinical sensitization stage (allergen immunoprophylaxis). Diagnostic algorithms based on singleplex or multiplex molecular IgE tests allow the discrimination of genuine from cross-reacting sensitization and the selection of the right extracts for allergen immunotherapy composition. Patients with extreme molecular poly-sensitization and greater risk of asthma or other IgE-mediated comorbidities, can be easily identified by means of allergen microarray or macroarray procedures and might benefit from anti-IgE treatment. IgE molecular tests have opened the era of precision allergology, and their routine use should aim at cost-effectiveness, according to the principles of the Choosing Wisely initiative.

Allergen immunotherapy (AIT) in asthma

Bronchial asthma remains one of the most common chronic diseases with a high degree of morbidity and still a considerable mortality with an increasing prevalence in many countries. Although remarkable progress has been made in the past decades in the medical treatment for asthma, curative or disease modifying approaches are still limited to allergen immunotherapy (AIT). Despite a plethora of potential immunological actions observed during AIT, the precise mechamisms that might exert beneficial effects especially in asthma remain unclear. Clinical studies in the past have suggested clinical benefits in symptom control and medication use with a small reduction in allergen-specific and non-specific bronchial hyperresponsiveness but these results were mainly derived from small, frequently suboptimally designed studies which were poorly comparable. Only recently have larger, dose ranging studies with well standardized allergens with patient relevant endpoints such as corticosteroid requirements for asthma control or the onset of exacerbations following inhaled corticosteroid (ICS) withdrawal corroborated the potential clinical effects of AIT in asthma, suggesting that it might replace some of the controller effects of ICS. In addition, newer, up-do-date designed studies support previous data that in patient populations at risk to develop asthma AIT might have a role in secondary prevention. Further studies on the long term effects as well as comparative studies are needed to further corroborate the role of AIT in the prevention and the control of asthma are needed.

Options of immunotherapeutic treatments for children with asthma

Introduction: Asthma is the most common chronic disease in children. Avoiding triggers, and pharmacologic treatment with short acting beta-agonist, inhaler corticosteroids and anti-leukotriene are often enough to obtain symptoms control. Nevertheless, there is a subset of children with severe asthma and poor symptom control despite maximal therapy. In these patients, anti-IgE and anti-IL5 monoclonal antibodies are suggested as the fifth step of Global Initiative for Asthma guidelines. Area covered: Immunotherapeutic treatments are now suggested for asthma management. This article will discuss the available evidence on allergen immunotherapy and biologic drugs in pediatric asthma treatment. Expert opinion: Previously published studies demonstrated a good efficacy and safety profile of Allergen Immunotherapy in patients with mild-moderate asthma and sensitization to one main allergen. New understanding of mechanisms underlying severe asthma inflammation has allowed the identifications of specific biomarkers guiding the clinician in the choice of patient specific drug. Among the suggested immunotherapeutic options, omalizumab (blocking IgE) remains the first choice for atopic 'early onset' asthma in patients aged over 6 years. Instead, mepolizumab (blocking the IL5 ligand) should be considered for 'eosinophilic' asthma. Other biologic drugs are under consideration but data on the pediatric population are still lacking.

Prospective comparison of a nonmodified and a modified mite extract for immunotherapy in children and adolescents

Aim: This prospective study compares nonmodified and modified house dust mite extracts for allergen immunotherapy (AIT) in pediatric patients with allergic asthma. Materials & methods: Total 95 patients underwent bronchial allergen provocation (BAP). AIT was recommended to 62 patients. Complete datasets of 54 subjects were obtained. Primary aim was the comparison of treatment success defined by BAP between two extracts after 1 year. Secondary parameters were laboratory parameters and clinical symptoms. Results: Significant improvement (p < 0.001) was measured by BAP in both treatment groups. No change was seen in the controls. Both extracts exerted comparable effects on all parameters. Conclusion: After 1 year of AIT, the extracts were equally efficient, with significant improvements in 70.0% (nonmodified) and 72.2% (modified) of patients.

Early Intervention is Important to Prevent Sensitization to New Allergens

We review current management for allergic rhinitis and possible new treatments for this condition. Management of allergic rhinitis includes promotion of protective factors, avoidance of allergens, and possibly immunotherapy. In recent years, the incidence of allergic rhinitis has increased in many countries. Early intervention at different stages is an important part of management. Allergic disease in infants has been described as the allergic march, commencing with atopic dermatitis accompanied by infantile asthma and progressing to perennial allergic rhinitis induced by house dust mite allergy. In order to prevent polysensitization, allergen-specific immunotherapy should probably be initiated at an earlier age, especially in children with rhinitis who show monosensitization to house dust mite antigens.

How molecular diagnosis may modify immunotherapy prescription in multi-sensitized pollen-allergic children

INTRODUCTION

Specific immunotherapy (SIT) is used to treat asthma and allergic rhinitis, and a dose-response relationship has been found for SIT efficacy, creating a need to accurately select the allergen used in therapy. This need is especially pronounced in poly-sensitized children living in areas where different pollen allergen sources coexist in the same season, as this circumstance complicates diagnostic efforts. In such cases, component-resolved diagnosis (CRD) can increase diagnostic accuracy and aid in SIT prescription.

MATERIALS AND METHODS

We hypothesized that CRD results would lead to modifications in classical immunotherapy prescription based on sources such as medical history, season of symptom presentation, and skin testing. We studied a sample of children indicated for immunotherapy in whom classical methods had not pointed out the most relevant allergen due to sensitization to more than two pollens. We used a small panel of recombinant allergens, analyzing the percentage of changes to prescription considering the findings of molecular studies.

RESULTS

Of the 70 children included, CRD led to modified immunotherapy prescription in 54.3%. Indications of single-allergen therapy increased from 18% to 51% when CRD was included. The decision to prescribe immunotherapy was reversed following CRD in 9.3% of cases.

DISCUSSION

CRD use alters the choice of specific immunotherapy in poly-sensitized children. A wide panel of recombinant allergens may not be necessary to improve immunotherapy indication using molecular techniques; rather, a smaller panel adapted to include those allergens prevalent in the geographical area in question appears to be sufficient for more effective immunotherapy, also leading to an improved cost-benefit ratio.

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

CONTEXT

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

OBJECTIVES

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

DATA SOURCES

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

STUDY SELECTION

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

DATA EXTRACTION

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

RESULTS

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

LIMITATIONS

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

CONCLUSIONS

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

SLIT's Prevention of the Allergic March

PURPOSE OF REVIEW

The progression of atopic disorders from atopic dermatitis in infants to allergic rhinitis and asthma in children, adolescents, and adults defines the allergy march. Allergen immunotherapy is the only causal treatment altering the immunological mechanism underlying the allergic diseases. The sublingual administration route is more acceptable than the subcutaneous one in pediatric age.

RECENT FINDINGS

Several studies show the efficacy and safety profile of sublingual immunotherapy (SLIT) for the treatment of respiratory allergy diseases, but few data are available on its effect of primary and secondary prevention of allergic disease. The purpose of this manuscript is to review the latest studies addressing the effect of SLIT on the development of new sensitizations in not sensitized or already sensitized patients and progression of the allergy march.

EAACI guidelines on allergen immunotherapy: Prevention of allergy

Allergic diseases are common and frequently coexist. Allergen immunotherapy (AIT) is a disease-modifying treatment for IgE-mediated allergic disease with effects beyond cessation of AIT that may include important preventive effects. The European Academy of Allergy and Clinical Immunology (EAACI) has developed a clinical practice guideline to provide evidence-based recommendations for AIT for the prevention of (i) development of allergic comorbidities in those with established allergic diseases, (ii) development of first allergic condition, and (iii) allergic sensitization. This guideline has been developed using the Appraisal of Guidelines for Research & Evaluation (AGREE II) framework, which involved a multidisciplinary expert working group, a systematic review of the underpinning evidence, and external peer-review of draft recommendations. Our key recommendation is that a 3-year course of subcutaneous or sublingual AIT can be recommended for children and adolescents with moderate-to-severe allergic rhinitis (AR) triggered by grass/birch pollen allergy to prevent asthma for up to 2 years post-AIT in addition to its sustained effect on AR symptoms and medication. Some trial data even suggest a preventive effect on asthma symptoms and medication more than 2 years post-AIT. We need more evidence concerning AIT for prevention in individuals with AR triggered by house dust mites or other allergens and for the prevention of allergic sensitization, the first allergic disease, or for the prevention of allergic comorbidities in those with other allergic conditions. Evidence for the preventive potential of AIT as disease-modifying treatment exists but there is an urgent need for more high-quality clinical trials.

Immunotherapeutic efficacy of liposome-encapsulated refined allergen vaccines against Dermatophagoides pteronyssinus allergy

Allergen specific immunotherapy (AIT) can modulate the allergic response causing a long-term symptom subsidence/abolishment which leads to reduced drug use and prevention of new sensitization. AIT of house dust mite allergy (HDM) using the mite crude extract (CE) as the therapeutic agent is not only less effective than the AIT for many other allergens, but also frequently causes adverse effects during the treatment course. In this study, mouse model of Dermatophagoides pteronyssinus (Dp) allergy was invented for testing therapeutic efficacies of intranasally administered liposome (L) encapsulated vaccines made of single Dp major allergens (L-Der p 1, L-Der p 2), combined allergens (L-Der p 1 and Der p 2), and crude Dp extract (L-CE). The allergen sparing intranasal route was chosen as it is known that the effective cells induced at the nasal-associated lymphoid tissue can exert their activities at the lower respiratory tissue due to the common mucosal traffic. Liposome was chosen as the vaccine delivery vehicle and adjuvant as the micelles could reduce toxicity of the entrapped cargo. The Dp-CE allergic mice received eight doses of individual vaccines/placebo on alternate days. All vaccine formulations caused reduction of the Th2 response of the Dp allergic mice. However, only the vaccines made of single refined allergens induced expressions of immunosuppressive cytokines (TGF-β, IL-35 and/or IL-10) which are the imperative signatures of successful AIT. The data emphasize the superior therapeutic efficacy of single refined major allergen vaccines than the crude allergenic extract vaccine.

Biological mechanisms underlying the clinical effects of allergen-specific immunotherapy in asthmatic children

INTRODUCTION

Allergen-specific immunotherapy (AIT) is indicated for patients with allergic asthma and/or allergic rhinitis, and can be implemented by either subcutaneous injection (SCIT) or sublingual administration (SLIT). AIT reduces asthma symptoms, lowers the use of pharmacologic controller therapy, and decreases the need for rescue medications. SLIT appears to be safer than SCIT, but SCIT seems to be more efficacious and acts earlier in allergic asthmatic children.

AREAS COVERED

This review looks at the pathobiology of allergic asthma as well as the role of regulatory T and B cells in allergen tolerance. It also reviews the immunological mechanisms underlying the clinical effects induced by AIT in allergic asthmatic children.

EXPERT OPINION

AIT is very effective in allergic asthmatic children, who can significantly benefit from this particular type of immunotherapy in order to achieve a better control of their disease. AIT is also capable of modifying the natural history of allergic asthma. Furthermore, AIT can potentially represent a valuable therapeutic tool within the context of precision medicine, as recombinant allergen technology might allow the creation of targeted extracts able to be effective against specific proteins to which individual asthmatic children are allergic, thus helping to implement a personalized approach to treatment.

Clinical evaluation for sublingual immunotherapy with Dermatophagoides farinae drops in adult patients with allergic asthma

PURPOSE

The efficacy and safety of sublingual immunotherapy (SLIT) in house dust mite-induced allergic asthma (AA) have yet to be firmly established, especially in adult patients. Our objective is to evaluate the efficacy of SLIT with Dermatophagoides farinae drops in adult patients with AA.

METHODS

One hundred and thirty-four adult patient data with house dust mite (HDM)-induced AA who had been treated for 2 years were collected. These patient data that we collected were divided into the SLIT group (n = 85) and control group (n = 49). All patients were treated with low to moderate dose of inhaled glucocorticoid and long-acting β2 agonists. Patients in the SLIT group were further treated with D. farinae drops. Clinical scores including the total asthma symptom score (TASS), total asthma medicine score (TAMS), asthma control test (ACT), and peak flow percentage (PEF%) were assessed before treatment and at yearly visits. The presence of adverse events (AEs) were recorded once a month.

RESULTS

Before treatment, the PEF% in the SLIT group was significantly lower than that in the control group (p < 0.05). After 2 years, both treatments were effective in the clinical scores when compared with baseline values (all p < 0.001). Meanwhile, the SLIT group showed significantly lower TASS and TAMS (all p < 0.001) and higher ACT (p < 0.001) and PEF% (p < 0.05) when compared with the control group. No severe systemic AEs were reported.

CONCLUSIONS

SLIT with D. farinae drops plus pharmacotherapy is more effective than routine drug treatment in adult patients with AA.

Natural Evolution of IgE Responses to Mite Allergens and Relationship to Progression of Allergic Disease: a Review

PURPOSE OF REVIEW

Allergenic molecules of the house dust mite (HDM) are crucially important indoor allergens, contributing to allergic rhinitis and asthma around the globe. In the past years, recombinant molecules for diagnostics opened new pathways to investigate individual sensitization profiles and new chances for the prevention and treatment of HDM allergy. This review summarizes the latest findings on the evolution of IgE responses towards mite allergens.

RECENT FINDINGS

Several cross-sectional and longitudinal studies confirmed the role of Der p 1 and Der p 2 as major allergenic proteins of the HDM. A newly identified player is the major allergen Der p 23. Apart from identifying the early sensitization towards this molecule as a risk factor for asthma in school age, a recent longitudinal study described sensitization patterns showing that the production of IgE usually starts towards a group of initiator proteins and may stay monomolecular or expand to an oligo- or even polymolecular stage. This phenomenon also correlates to clinical symptoms. A relation between a broad sensitization pattern and symptom severity has also been shown cross-sectionally. Individual sensitization profiles towards HDM allergens provide important information to evaluate a patient's current stage and risk for clinical symptoms. This knowledge paves the way for an early and adequate prevention and/or treatment.

The effect of allergen immunotherapy in the onset of new sensitizations: a meta-analysis

BACKGROUND

Although the preventive efficacy of allergen immunotherapy (AIT) in the onset of new allergen sensitizations has been asserted by many reviews, position papers, and consensus conferences, the evidence available is from only 3 studies. The objective of this work was a systematic review to evaluate the preventive efficacy of AIT in the onset of new allergen sensitizations. The end-point was the risk difference (RD) in the onset of new allergen sensitizations between patients treated with AIT and pharmacotherapy.

METHODS

Computerized bibliographic searches of MEDLINE, EMBASE, and the Cochrane Library (until November 30th, 2016) were done. Random-effects and fixed-effects model meta-analyses were performed. Randomized controlled trials or observational studies comparing children treated with AIT with house dust mite (HDM) to subjects who did not receive AIT, with a long-term observation period (at least 3 years including treatment and follow-up) have been included.

RESULTS

Eight studies totaling 721 children (390 treated with AIT and 331 with pharmacotherapy) met the inclusion criteria. The risk of bias was high. Low evidence supports the conclusion that AIT prevents the onset of new allergen sensitizations, with 3 of 8 studies reporting a reduction in the onset of new sensitizations in patients treated with AIT vs pharmacotherapy. Our meta-analysis found no difference between AIT and pharmacotherapy, with high heterogeneity (RD, -0.10; 95% confidence interval [CI], -0.31 to 0.11; p = 0.32; I² = 91.4%).

CONCLUSION

The data of this systematic review do not support a preventive effect in the onset of new allergen sensitizations, in children treated with AIT in comparison with those treated with pharmacotherapy.

Efficacy of allergen immunotherapy in reducing the likelihood of developing new allergen sensitizations: a systematic review

BACKGROUND

Guidelines and position papers indicate that allergen immunotherapy (AIT) is the only disease-modifying treatment, including prevention of the onset of new allergen sensitizations. However, this preventive effect was shown by only a few observational studies. Our aim was to systematically review the efficacy of AIT in preventing the onset of new allergen sensitizations.

METHODS

Computerized bibliographic searches of Medline, EMBASE, and the Cochrane Library (through June 2015) were supplemented with manual searches of reference lists. Observational studies or randomized controlled trials with a long-term observation period were included. Paired reviewers extracted data about study characteristics and assessed biases. The end point was the risk difference in the onset of new allergen sensitizations between patients treated with AIT and pharmacotherapy. The strength of the evidence was graded based on the risk of bias, consistency, and magnitude of effect, according to the GRADE Working Group's guide.

RESULTS

Eighteen studies (1049 children, 10 057 adults) met the inclusion criteria. The risk of bias was high in all but one study. Low evidence supports the position that AIT prevents the onset of new allergen sensitizations, with 10 of 18 studies reporting a reduction in the onset of new sensitizations in patients treated with AIT vs placebo. Small studies and studies with a shorter follow-up showed the highest benefit of AIT.

CONCLUSIONS

The overall evidence provides a low-grade level of the evidence supporting the efficacy of AIT in preventing the onset of new allergen sensitizations, but high-quality studies could change this estimate.

Allergen immunotherapy for the prevention of allergy: A systematic review and meta-analysis

BACKGROUND

There is a need to establish the effectiveness, cost-effectiveness, and safety of allergen immunotherapy (AIT) for the prevention of allergic disease.

METHODS

Two reviewers independently screened nine international biomedical databases. Studies were quantitatively synthesized using random-effects meta-analyses.

RESULTS

A total of 32 studies satisfied the inclusion criteria. Overall, meta-analysis found no conclusive evidence that AIT reduced the risk of developing a first allergic disease over the short term (RR = 0.30; 95% CI: 0.04-2.09) and no randomized controlled evidence was found in relation to its longer-term effects for this outcome. There was, however, a reduction in the short-term risk of those with allergic rhinitis developing asthma (RR = 0.40; 95% CI: 0.30-0.54), with this finding being robust to a pre-specified sensitivity analysis. We found inconclusive evidence that this benefit was maintained over the longer term: RR = 0.62; 95% CI: 0.31-1.23. There was evidence that the risk of new sensitization was reduced over the short term, but this was not confirmed in the sensitivity analysis: RR = 0.72; 95% CI: 0.24-2.18. There was no clear evidence of any longer-term reduction in the risk of sensitization: RR = 0.47; 95% CI: 0.08-2.77. AIT appeared to have an acceptable side effect profile.

CONCLUSIONS

AIT did not result in a statistically significant reduction in the risk of developing a first allergic disease. There was, however, evidence of a reduced short-term risk of developing asthma in those with allergic rhinitis, but it is unclear whether this benefit was maintained over the longer term. We are unable to comment on the cost-effectiveness of AIT.

Allergen-specific immunotherapy in pediatric allergic asthma

Allergen-specific immunotherapy (AIT) is the only curative way that can change the immunologic response to allergens and thus can modify the natural progression of allergic diseases. There are some important criteria which contributes significantly on efficacy of AIT, such as the allergen extract used for treatment, the dose and protocol, patient selection in addition to the severity and control of asthma. The initiation of AIT in allergic asthma should be considered in intermittent, mild and moderate cases which coexisting with other allergic diseases such as allergic rhinitis, and in case of unacceptable adverse effects of medications. Two important impact of AIT; steroid sparing effect and preventing from progression to asthma should be taken into account in pediatric asthma when making a decision on starting of AIT. Uncontrolled asthma remains a significant risk factor for adverse events and asthma should be controlled both before and during administration of AIT. The evidence concerning the efficacy of subcutaneous (SCIT) and sublingual immunotherapy (SLIT) for treatment of pediatric asthma suggested that SCIT decreases asthma symptoms and medication scores, whereas SLIT can ameliorate asthma symptoms. Although the effectiveness of SCIT has been shown for both seasonal and perennial allergens, the data for SLIT is less convincing for perennial allergies in pediatric asthma.

Specific immunotherapy for allergic rhinitis in children

PURPOSE OF REVIEW

Allergic rhinitis is a highly prevalent inflammatory disease affecting 20-40% of the children worldwide. Allergen-specific immunotherapy (SIT) is an effective treatment for allergic rhinitis. This article reviews the recent advances in SIT for children.

RECENT FINDINGS

In current clinical practice, immunotherapy is delivered as either subcutaneous immunotherapy or sublingual immunotherapy (SLIT). Most meta-analyses and reviews concluded a trend that subcutaneous immunotherapy was better than SLIT in reducing symptoms of allergic rhinitis and rescue medication use, however, SLIT has a better safety profile than subcutaneous immunotherapy. Additionally, the absence of pain on administration of therapy is a character of SLIT, which is well suited for children. T regulatory cells, especially Tr1 cells that secrete interleukin-10 and induce production of immunoglobulin G4, play a role during SIT.

SUMMARY

Although there is substantial evidence for effectiveness of both subcutaneous immunotherapy and SLIT, safer and more effective SIT approaches are needed. New approaches to improve SIT include omalizumab pretreatment, use of recombinant allergens, and alternate routes of administration.

Dexamethasone suppresses allergic rhinitis and amplifies CD4(+) Foxp3(+) regulatory T cells in vitro

BACKGROUND

Glucocorticosteroids (GCs) are highly effective in mitigating allergic inflammation. In this study, we investigate the effects of dexamethasone (DEX) on regulatory T cells (Tregs) in a murine model of allergic rhinitis (AR).

METHODS

BALB/c mice were sensitized to ovalbumin (OVA) followed by intranasal OVA challenge. Mice in the treatment group received DEX by intraperitoneal injection (5 mg/kg/day) 1 hour before the OVA challenge. Further, CD4(+) CD25(-) T cells from the spleens were cultured in presence of DEX. The effects of DEX on CD4(+) Foxp3(+) T cells were then assessed in vivo as well as in vitro.

RESULTS

Frequencies of sneezing and scratching decreased significantly in the DEX-treated group compared to that in the OVA group. Histopathological analyses showed that DEX restored the destroyed and discontinuous ciliated epithelium of the nasal mucosa in the OVA group. Moreover, DEX inhibited the production of interleukin (IL)-4, IL-5, and IL-13 in the nasal cavity lavage fluid in this group. We also observed a significant increase in the percentage of CD4(+) Foxp3(+) T cells in the OVA group. In vivo, DEX treatment significantly decreased the number of CD4(+) Foxp3(+) T cells. However, in vitro, the proportion of these cells increased in the presence of DEX. Furthermore, the number of late stage apoptotic CD4(+) T cells was also significantly increased upon exposure to DEX.

CONCLUSION

DEX therapy effectively suppresses AR symptoms, but does not result in the expected increase in the frequency of Tregs in vivo. Thus, whether GCs exert immunosuppressive effects by influencing the number of Tregs remains unresolved.

Improvement and prevention of asthma with concomitant treatment of allergic rhinitis and allergen-specific therapy

BACKGROUND

Asthma and allergic rhinitis are 2 of the most prevalent chronic medical diseases. Asthma is estimated to affect 8% of adults and 9% of children, with nearly 300 million people affected worldwide. Poorly controlled allergic rhinitis may be associated with worsening asthma symptoms over time. Various treatments have been proposed in the improvement and prevention of asthma in children and adults with allergic symptoms, which have included pharmacotherapy with antihistamines and topical intranasal corticosteroids, as well as allergen-specific immunotherapy.

METHODS

Articles were selected through PubMed and personal knowledge of the authors based on a comprehensive literature review examining whether treatment of allergic rhinitis improves and/or prevents concomitant symptoms of asthma. The largest and highest-quality studies were included in the literature review. The search selection was not standardized. Articles written in a language other than English were excluded.

RESULTS

Clinical trials have showed improvement in asthma symptoms with concomitant treatment of allergic rhinitis with antihistamines and topical intranasal corticosteroids, though improvement in objective pulmonary function parameters has not been uniformly demonstrated with antihistamine use alone. There is very strong evidence to suggest that subcutaneous and sublingual immunotherapy may in addition prevent the progression of asthma in high-risk atopic patients by inducing immunological tolerance.

CONCLUSION

Traditional pharmacotherapy with antihistamines and topical intranasal steroids has been shown to improve allergic rhinitis symptoms with concomitant allergic asthma; however, only allergen-specific immunotherapy offers long-term control in improving asthma symptoms, exacerbations, and likely ultimate prevention in developing asthma.

Immunotherapy for house dust mite sensitivity: where are the knowledge gaps?

House dust mites (HDMs) are found in the environments where human habitation exists. Their density is dependent on environmental relative humidity; therefore, higher populations are present in areas of the world with higher humidity levels, e.g., coastal areas and tropics. To date, 24 HDM allergens have been identified. Many of these represent digestive enzymes since HDM feces are the major source of allergen exposure. IgE- medicated sensitization to HDM allergens is an important factor in the pathogenesis of allergic diseases since it is the most common aeroallergen detected by skin testing or in vitro IgE assays. Sensitization to HDM allergens often occurs early in life and appears to play an important role in the progression from allergic rhinitis to asthma (the so-called Allergic March) in children. HDM sensitization is also associated with asthma across all age groups. Efforts to control environmental exposure to HDM allergens have often proven to be unsuccessful. While medications can improve symptoms, only immunotherapy currently provides disease-modifying effects in allergic rhinitis and asthma. Several systemic reviews and meta-analysis indicate that both subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) are effective in the treatment of allergic rhinitis and asthma for HDM sensitivity. In this report, we review recent studies and the evidence for the use of HDM SCIT and SLIT. Fundamental gaps in knowledge are identified which could lead to improved approaches to HDM allergy.

Reduction of the number of major representative allergens: from clinical testing to 3-dimensional structures

Vast amounts of allergen sequence data have been accumulated, thus complicating the identification of specific allergenic proteins when performing diagnostic allergy tests and immunotherapy. This study aims to rank the importance/potency of the allergens so as to logically reduce the number of allergens and/or allergenic sources. Meta-analysis of 62 allergenic sources used for intradermal testing on 3,335 allergic patients demonstrated that in southern China, mite, sesame, spiny amaranth, Pseudomonas aeruginosa, and house dust account for 88.0% to 100% of the observed positive reactions to the 62 types of allergenic sources tested. The Kolmogorov-Smironov Test results of the website-obtained allergen data and allergen family featured peptides suggested that allergen research in laboratories worldwide has been conducted in parallel on many of the same species. The major allergens were reduced to 21 representative allergens, which were further divided into seven structural classes, each of which contains similar structural components. This study therefore has condensed numerous allergenic sources and major allergens into fewer major representative ones, thus allowing for the use of a smaller number of allergens when conducting comprehensive allergen testing and immunotherapy treatments.

Safety of immunotherapy in patients with rhinitis, asthma or atopic dermatitis using an ultra-rush buildup. A retrospective study

BACKGROUND

Allergen-specific immunotherapy is a proven, highly effective treatment for IgE-mediated diseases. However, ultra-rush immunotherapy is prescribed infrequently because of the perception that accelerated immunotherapy buildup leads to a higher rate of systemic reactions.

OBJECTIVE

To evaluate the frequency of adverse reactions in patients with IgE-mediated diseases receiving house dust mite (HDM) ultra-rush immunotherapy.

METHODS

A retrospective, observational study was conducted for patients with IgE-mediated diseases receiving allergen-specific immunotherapy. Subcutaneous immunotherapy with depigmented polymerized mites extract was administered in two refracted doses of 0.2 and 0.3 ml at first injection, and in single 0.5 ml doses in subsequent monthly injections. A 30 min observation time was required after each injection. Systemic reactions were graded using the World Allergy Organisation grading system.

RESULTS

575 patients were included. The age range was 1-83 years. Most patients had respiratory diseases (544) and 101 patients had atopic dermatitis. A total of 27 patients (4.6%) experienced 139 reactions (reactions/injections: 1.9%); 22 patients (3.8%) experienced 134 local reactions (local reactions/injections: 1.8%). Eight patients (1.3%) experienced eight systemic reactions (systemic reactions/injections: 0.1%). Five systemic reactions were grade 2 and three grade 1. Two systemic reactions were reported during buildup. There were no fatalities.

CONCLUSION

Taking into account the possible bias for the retrospective design of this study we observed that immunotherapy for patients with IgE-mediated diseases using a depigmented polymerized mites extract, with an ultra-rush buildup, has similar frequency of systemic reactions than that seen in slower buildup immunotherapy in other studies. Accelerated buildup could improve patients' adherence and reduce dropout rates.

Recombinant house dust mite allergens

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

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

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

Allergen-specific immunotherapy for pediatric asthma and rhinoconjunctivitis: a systematic review

BACKGROUND AND OBJECTIVE

Subcutaneous immunotherapy (SCIT) is approved in the United States for the treatment of pediatric asthma and rhinitis; sublingual immunotherapy (SLIT) does not have regulatory approval but is used in clinical practice. The objective of this study was to systematically review the evidence regarding the efficacy and safety of SCIT and SLIT for the treatment of pediatric asthma and allergic rhinoconjunctivitis.

METHODS

Two independent reviewers selected articles for inclusion, extracted data, and graded the strength of evidence for each clinical outcome. All studies were randomized controlled trials of children with allergic asthma or rhinoconjunctivitis treated with SCIT or an aqueous formulation of SLIT. Data sources were Medline, Embase, LILACS, CENTRAL, and the Cochrane Central Register of Controlled Trials through May 2012.

RESULTS

In 13 trials, 920 children received SCIT or usual care; in 18 studies, 1583 children received SLIT or usual care. Three studies compared SCIT with SLIT head-to-head in 135 children. The strength of evidence is moderate that SCIT improves asthma and rhinitis symptoms and low that SCIT improves conjunctivitis symptoms and asthma medication scores. Strength of evidence is high that SLIT improves asthma symptoms and moderate that SLIT improves rhinitis and conjunctivitis symptoms and decreases medication usage. The evidence is low to support SCIT over SLIT for improving asthma or rhinitis symptoms or medication usage. Local reactions were frequent with SCIT and SLIT. There was 1 report of anaphylaxis with SCIT.

CONCLUSIONS

Evidence supports the efficacy of both SCIT and SLIT for the treatment of asthma and rhinitis in children.

Changes in IL-10 and specific antibodies associated to successful Dermatophagoides pteronyssinus immunotherapy in children during the first year of treatment

BACKGROUND

Allergen-specific immunotherapy (SIT) is a long-term treatment of respiratory allergy.

OBJECTIVE

To look for early predictors of the effectiveness of Dermatophagoides pteronyssinus SIT.

METHODS

A prospective multi-centre study was carried out in Spain. Children with D. pteronyssinus rhinitis or asthma were invited to participate. The study was divided into times: T0 (recruitment); T1 (inclusion); T2 a-f (immunotherapy times) and T3 (the end of study). Efficacy of SIT was assessed by clinical scores, visual analogue scales (VAS) and lung function tests. We performed D. pteronyssinus skin tests at T1 and T3, and determined specific serum IgE, IgG4 and IL-10 at T1, T2f and T3. Data were analysed using Mann-Whitney and Kruskal-Wallis tests, compared using Wilcoxon and Chi-square tests, and correlated to Spearman test. All tests had a significance level of 0.05.

RESULTS

Thirty-eight children completed the study. At T1 all had rhinitis and 34 also had asthma. At T3, 30 patients had improved, six experienced no changes and two worsened. Improvement was associated to FEV1/FVC and VAS improvement; to a reduction in D. pteronyssinus skin prick test; to a progressive increase in serum levels of D. pteronyssinus IgE, and D. pteronyssinus, Der p1 and Der p2 IgG4. IL-10 levels showed an early increase at T2f (the end of initial build-up immunotherapy phase), and then a reduction at T3 (the end of a year of immunotherapy). Improvement associated to an early increase in IL-10 and was correlated with VAS and specific IgG4 evolution.

House dust allergy and immunotherapy

HDM allergy is associated with asthma, allergic rhinitis and atopic dermatitis. In many countries childhood asthma is predominantly found in HDM-allergic children with their probability of developing disease being proportional to their IgE antibody titers and the early development of Th2 responses. While the pathogenesis is complex and increasingly linked to infection the immunologically-based allergen immunotherapy and anti-IgE antibody therapy are highly beneficial. Immunotherapy could be a short-term treatment providing lifelong relief but the current regimens depend on repeated administration of allergen over years. Immunological investigations point to a contribution of responses outside the Th2 pathway and multiple potential but unproven control mechanisms. Over half of the IgE antibodies are directed to the group 1 and 2 allergens with most of remainder to the group 4, 5, 7 and 21 allergens. This hierarchy found in high and low responders provides a platform for introducing defined allergens into immunotherapy and defined reagents for investigation.

Allergen immunotherapy in allergic respiratory diseases: from mechanisms to meta-analyses

Allergen-specific immunotherapy (SIT) involves the repeated administration of allergenic extracts to atopic individuals over a period of 3 to 5 years either subcutaneously (SCIT) or sublingually (SLIT) for the treatment of allergic respiratory diseases, including asthma and allergic rhinitis (AR). In studies, SCIT and SLIT have been shown to improve existing symptoms of asthma and AR and to also have the capability to cause disease-modifying changes of the underlying atopic condition so as to prevent new allergic sensitization as well as arrest progression of AR to asthma. Recent evidence suggests that immunotherapy brings about these effects through actions that use T-regulatory cells and blocking antibodies such as IgG(4) and IgA(2,) which can then result in an "immune deviation" from a T-helper (Th) 2 cell pattern to a Th1 cell pattern. Numerous meta-analyses and studies have been performed to evaluate the existing data among these studies, with the consensus recommendation favoring the use of immunotherapy because of its potential to modify existing diseases. Significant adverse reactions can occur with immunotherapy, including anaphylaxis and, very rarely, death. A primary factor in considering SIT is its potential to provide long-lasting effects that are able to be sustained well after its discontinuation. Given the significant burden these allergic diseases impose on the health-care system, SIT appears to be a cost-effective adjunctive treatment in modifying the existing disease state.

House dust mite-specific immunotherapy alters the basal expression of T regulatory and FcεRI pathway genes

BACKGROUND

Regulatory T (Treg) cells and IgE-mediated signaling pathways could play important roles in the induction of allergen tolerance during house dust mite-specific subcutaneous immunotherapy (HDM-SCIT). Our aim was to compare the basal expression levels of Treg, T helper 1 (Th1) and Th2 transcription factors and components involved in IgE-mediated signaling in healthy subjects with those in HDM-allergic patients both untreated and successfully treated with HDM-SCIT.

METHODS

Thirty-nine HDM-allergic patients who completed a 3- to 5-year course of mite extract SCIT, 20 mite-allergic controls and 25 healthy controls participated in this study. The efficacy of SCIT was monitored using skin-prick tests (SPTs), total immunoglobulin E (tIgE), specific IgE (sIgE), sIgG(4), nasal challenge and visual analog scale (VAS) scores at several time points. The mRNA levels of forkhead box protein 3 (FOXP3), T-BET, GATA-3, FcεRI, spleen tyrosine kinase (Syk), phosphatidylinositol 3 kinase (PI3K) and SH2 domain-containing inositol phosphatase (SHIP) were quantified by real-time RT-PCR using nonstimulated whole blood samples.

RESULTS

Decreased wheal sizes and VAS scores, negative challenges and increased sIgG(4) levels indicated that SCIT was effective in the treated patients. Basal expression levels of FOXP3 and GATA-3 decreased and T-BET levels increased in both treated patients and in healthy controls compared to untreated patients. The IgE-mediated pathway kinases Syk and PI3K exhibited reduced expression, whereas SHIP phosphatase levels were elevated in both treated patients and healthy controls relative to untreated patients. The expression levels of FcεRI were not significantly altered.

CONCLUSIONS

Immunotherapy using HDM extracts results in a modification of the basal expression levels of several IgE-related signaling factors and induces a highly significant upregulation of Th1-response and downregulation of Th2-response transcription factors. Interestingly, this therapy also appears to reduce the basal expression of FOXP3.