Evidence of effect of subcutaneous immunotherapy in children: complete and updated review from 2006 onward

Physicians' experience and opinion on contraindications to allergen immunotherapy: The CONSIT survey

BACKGROUND

Allergen immunotherapy (AIT) is the only disease-modifying treatment in allergy but several contraindications limit its use.

OBJECTIVE

To collect the outcome of using AIT in theoretically contraindicated situations in real patients in the Contraindications to Specific ImmunoTherapy (CONSIT) survey.

METHODS

The CONSIT is an electronic European Academy of Allergy and Clinical Immunology survey conducted to gather the safety outcomes of patients undergoing subcutaneous, sublingual, or venom AIT and the opinions of physicians on each of 17 selected conditions: children younger than 5 years; starting AIT during pregnancy; controlled severe asthma; arrhythmias; coronary disease; cancer; autoimmune disease; bone marrow and solid organ transplantation; human immunodeficiency virus and acquired immunodeficiency syndrome; previous anaphylaxis during AIT; use of β-blockers, angiotensin-converting inhibitors, cyclosporine, and methotrexate; and inability to communicate. Safety using AIT was reported in a 3-point scale: 1, "no problems"; 2, "minor problems" (requiring only dose modifications); and 3, "major problems" (AIT not tolerated). Each physician was asked about the degree of contraindication that each condition should have: no contraindication (score 1), relative contraindication (score 2), or absolute contraindication (score 3).

RESULTS

Five hundred twenty physicians (75% Europeans, 89% allergists) reported on approximately 45,000 patients undergoing AIT with any of these conditions. Major problems were infrequent, occurring more frequently in patients with asthma (9.9%) and with previous anaphylaxis from AIT (9.5%). Regarding opinions, experienced physicians scored a significantly lower mean for all conditions than non-experienced physicians for all routes.

CONCLUSION

Major problems were infrequent and experienced physicians were less likely to be restrictive in the use of AIT.

Allergen immunotherapy for the treatment of allergic rhinitis and/or asthma: an umbrella review

BACKGROUND

Allergic rhinitis and asthma are important public health concerns, yet there is no consensus about the benefits and harms of allergen-specific immunotherapy to treat these conditions. We performed an umbrella review of systematic reviews summarizing the current evidence for the benefits and harms of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT).

METHODS

We searched MEDLINE, Embase, the Cochrane Library and the grey literature from Jan. 1, 2010 to Nov. 20, 2016 for systematic reviews of randomized controlled trials or prospectively controlled studies involving children or adults with allergic rhinitis or asthma. Outcomes were summarized narratively (benefits: total combined symptom-medication score, symptom score, medication score, disease-specific quality of life, adherence; harms: anaphylaxis, death, local and systemic reactions).

RESULTS

Twenty-three systematic reviews were included. SCIT and SLIT were more effective than placebo for most outcomes. SCIT was better than SLIT at improving medication and symptom scores, with no differences in quality of life; however, data were limited for this comparison. Anaphylaxis and death were infrequently reported. Few reviews assessed benefits or harms among children.

INTERPRETATION

Allergen immunotherapy appears to be effective among patients with allergic rhinitis and asthma. The safety of allergen immunotherapy is not conclusively established, although death and anaphylaxis appear to be rare. PROSPERO no.: CRD42015024590.

Clinical practice recommendations for allergen-specific immunotherapy in children: the Italian consensus report

Allergen-specific immunotherapy (AIT) is currently recognized as a clinically effective treatment for allergic diseases, with a unique disease-modifying effect. AIT was introduced in clinical practice one century ago, and performed in the early years with allergenic extracts of poor quality and definition. After the mechanism of allergic reaction were recognized, the practice of AIT was refined, leading to remarkable improvement in the efficacy and safety profile of the treatment. Currently AIT is accepted and routinely prescribed worldwide for respiratory allergies and hymenoptera venom allergy. Both the subcutaneous (SCIT) and sublingual (SLIT) routes of administration are used in the pediatric population.AIT is recommended in allergic rhinitis/conjunctivitis with/without allergic asthma, with an evidence of specific IgE-sensitization towards clinically relevant inhalant allergens. Long-term studies provided evidence that AIT can also prevent the onset of asthma and of new sensitizations. The favorable response to AIT is strictly linked to adherence to treatment, that lasts 3-5 years. Therefore, several factors should be carefully evaluated before starting this intervention, including the severity of symptoms, pharmacotherapy requirements and children and caregivers' preference and compliance.In recent years, there have been increasing interest in the role of AIT for the treatment of IgE-associated food allergy and extrinsic atopic dermatitis. A growing body of evidence shows that oral immunotherapy represents a promising treatment option for IgE-associated food allergy. On the contrary, there are still controversies on the effectiveness of AIT for patients with atopic dermatitis.This consensus document was promoted by the Italian Society of Pediatric Allergy and Immunology (SIAIP) to provide evidence-based recommendations on AIT in order to implement and optimize current prescription practices of this treatment for allergic children.

Conjunctival allergen provocation test : guidelines for daily practice

Conjunctival allergen provocation test (CAPT) reproduces the events occurring by instilling an allergen on the ocular surface. This paper is the compilation of a task force focussed on practical aspects of this technique based on the analysis of 131 papers. Main mechanisms involved are reviewed. Indications are diagnosing the allergen(s)-triggering symptoms in IgE-mediated ocular allergy in seasonal, acute or perennial forms of allergic conjunctivitis, especially when the relevance of the allergen is not obvious or in polysensitized patients. Contraindications are limited to ongoing systemic severe pathology, asthma and eye diseases. CAPT should be delayed if receiving systemic steroids or antihistamines. Local treatment should be interrupted according to the half-life of each drug. Prerequisites are as follows: obtaining informed consent; evidencing of an allergen by skin prick tests and/or serum-specific IgE dosages; being able to deal with an unlikely event such as acute asthma exacerbation, urticaria or anaphylaxis, or an exacerbation of allergic conjunctivitis. Allergen extracts should be diluted locally prior to administration. Positive criteria are based on itching or quoted according to a composite score. An alternative scoring is based on itching. CAPT remains underused in daily practice, although it is a safe and simple procedure which can provide valuable clinical information.

The Functional IgE-Blocking Factor Induced by Allergen-Specific Immunotherapy Correlates with IgG4 Antibodies and a Decrease of Symptoms in House Dust Mite-Allergic Children

BACKGROUND

At present, there are no validated biomarkers reflecting or predicting the clinical efficacy of allergen-specific immunotherapy (AIT) . We aimed to investigate the correlations between clinical and immunological responses of patients undergoing house dust mite (HDM) AIT.

METHODS

Sixty-nine children diagnosed with HDM allergic rhinitis and/or asthma received standardized Dermatophagoides pteronyssinus (Dp) subcutaneous AIT for 12 months. Twenty HDM-allergic children served as an open control group. Clinical symptom and medication scores were recorded and Dp-specific IgE, IgG4 and IgE-blocking factor were measured before AIT and after 4 and 12 months of AIT.

RESULTS

Symptom scores decreased after 4 months and continued to decrease during 12 months of AIT. No differences in medication scores were observed between AIT and the control group during the study period. Levels of Dp IgG4 increased after 4 months and correlated to symptom scores at 12 months (r = -0.296, p = 0.013) of AIT. The Dp IgE-blocking factor increased after 4 months of AIT, and correlated with symptom scores at 4 months (r = -0.307, p = 0.010) and 12 months (r = -0.288, p = 0.016) of AIT. A strong correlation between Dp IgE-blocking factor and Dp IgG4 during AIT (4 months: r = 0.680; 12 months: r = 0.636, both p < 0.0001) was observed. Patients with IgE-blocking factor ≥0.2 after 4 months of AIT showed lower symptom scores at 12 months of AIT (p = 0.0093).

CONCLUSIONS

Subcutaneous HDM AIT results in a decrease of allergic symptoms among HDM-allergic children. IgE-blocking activity increased after 4 months of AIT and correlated with clinical symptoms. A high IgE-blocking factor at an early stage of AIT is associated with fewer symptoms at a later stage of AIT.

Selection of patients for sublingual versus subcutaneous immunotherapy

Allergen immunotherapy is the sole treatment for IgE-mediated allergic diseases directed at the underlying mechanism. The two widely accepted administration routes are sublingual (SLIT) and subcutaneous (SCIT). We reviewed how patients should best be selected for immunotherapy and how the optimal administration route can be defined. Before deciding SCIT or SLIT, appropriate selection of patients for allergen immunotherapy (AIT) is mandatory. To be eligible for AIT, subjects must have a clear medical history of allergic disease, with exacerbation of symptoms on exposure to one or more allergens and a corresponding positive skin or in vitro test. Then the route of administration should be based on: published evidence of clinical and immunologic efficacy (which varies per allergic disease and per allergen); mono- or multi-allergen immunotherapy, for SLIT multi-allergen immunotherapy was not effective; safety: adverse events with SLIT are more frequent, but less severe; and, costs and patient preferences, closely related to adherence issues. All these are discussed in the article.

Optimal duration of allergen immunotherapy in children with dust mite respiratory allergy

BACKGROUND

Subcutaneous immunotherapy (SCIT) discontinuation data in children remain scarce.

OBJECTIVE

We sought for differences in the clinical efficacy of 3 vs. 5 yr of SCIT in children with dust mite respiratory allergy.

METHODS

We performed a 5-yr, phase IV prospective study. After the first year, the patients were randomized to 3 (IT3) or 5 yr of treatment (IT5). Efficacy was assessed at 3rd and 5th year by symptom and medication scores and visual analog scales (VAS). Skin tests with common allergens and in vitro assessments were also performed.

RESULTS

Eighty-one children (mean age: 9 yr) were randomly assigned to 3 (IT3: 41) or 5 yr (IT5: 40) of immunotherapy. After 3 years, rhinitis global scores decreased in IT3 (44%; p = 0.002) and in IT5 (50%; p = 0.001). Asthma global, symptom and medication scores decreased by 100% in IT3 (p = 0.001) and IT5 (p = 0.001). VAS scores also diminished significantly (IT3: 70%, p = 0.001; IT5: 62.5%; p = 0.001). At 5th year, global rhinitis scores were reduced an additional 30% in IT5 children. Comparisons between both groups did not show differences in rhinitis (p = 0.055), asthma global scores (p = 0.948) or VAS scores at 5th year. Twenty percent of IT5 (p = 0.002) and 7% of IT3 children (p = 0.705) developed new sensitizations. At 5th year, sIgG4 determinations decreased in IT3 without significant variations in IT5.

CONCLUSIONS

Three years of SCIT induced significant improvement in children with dust mite respiratory allergy, but a 5-yr course added clinical improvement in rhinitis.

Will sublingual immunotherapy offer benefit for asthma?

Evidence shows that sublingual immunotherapy (SLIT) is indicated in patients with allergic rhinitis (AR). In this article we discuss whether SLIT could offer benefit for children and adults with asthma.We reviewed individual trials on SLIT in asthmatic patients, but also asthma data reported in some SLIT trials conducted in AR patients. Findings were complemented with data from systematic reviews and metaanalysis on the subject since 2000 and some guidelines that mention immunotherapy for asthma treatment. In AR patients with concomitant persistent asthma, SLIT reduces medication needs while maintaining symptom control. This holds especially true for house dust mite SLIT. Data on pollen SLIT and lung symptom improvement with SLIT, however, are less convincing. Therefore, we suggest SLIT should be added as an optional add-on therapy for patients with asthma whenever a causative allergen has been demonstrated and AR is associated with asthma. For the future, SLIT should be studied in specifically designed asthma studies in allergic asthmatics without AR.

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.

Influence of subcutaneous specific immunotherapy on drug costs in children suffering from allergic asthma

Background

Subcutaneous specific immunotherapy (SCIT) is an effective treatment attenuating the progression of allergic asthma. To date, there is a lack of studies investigating the economic consequences of SCIT on health care expenditures.

Methods

A health-economic piggy-back analysis of SCIT was conducted based on a RCT that enrolled 65 children and adolescents with allergic asthma. Patients were allocated into two groups: A group receiving SCIT with a high-dose hypoallergenic house dust mite preparation plus asthma medication and a control group receiving only asthma medication. For both groups asthma control was achieved before the start of the SCIT treatment and was maintained during the study. Both, costs and cost-effectiveness of SCIT with the high-dose hypoallergenic house dust mite preparation were investigated based on total medication costs, incremental medication costs and treatment effects (measured as lung function), respectively. A bootstrap analysis was performed to validate the results.

Results

A steady decline in medication costs could be observed in the SCIT group one year after treatment start compared to the control group. This cost trend became statistically significant 3 years after SCIT started. The calculated potential savings in the SCIT group correlated with an improved lung function. The distribution of the bootstrap results revealed that the probability of SCIT having a superior effectiveness compared to the control group is around 90%.

Conclusion

SCIT with a high-dose hypoallergenic preparation received by children and adolescents suffering from mite induced allergic asthma reduces the allergic medication intake and has cost-saving effects. Additional costs associated with SCIT may be completely compensated by drug cost savings 4 years after end of SCIT. Additionally, SCIT is superior compared to routine care as measured by the lung function that improved in SCIT-treated patients. Trial registration: (EudraCT no. 2004 – 003892 – 35).

Pediatric sublingual immunotherapy efficacy: evidence analysis, 2009-2012

OBJECTIVE

To perform a structured analysis of the latest scientific evidence obtained for the clinical efficacy of sublingual immunotherapy (SLIT) in children.

DATA SOURCES

PubMed, Embase, reference lists from reviews, and personal databases were reviewed for original articles on clinical trials with SLIT in patients younger than 18 years published from January 1, 2009, through December 31, 2012, using broad search and medical subject heading terms.

STUDY SELECTIONS

Clinical trials, irrespective of their design, of SLIT in the treatment of respiratory and food allergy in patients 18 years or younger were selected. Clinical outcomes (symptom scores, medication use, provocation tests, pulmonary function tests, skin prick tests, and adverse events) and immunologic changes were tabulated. Quality of each trial and total quality of compounded evidence was analyzed with the Grading of Recommendations Assessment, Development and Evaluation system.

RESULTS

Of 56 articles, 29 met the inclusion criteria. New evidence is robust for the precoseasonal tablet and drop grass pollen SLIT efficacy in allergic rhinitis and scarce for seasonal asthma. Some evidence for Alternaria SLIT efficacy is appearing. For house dust mite (HDM) SLIT in asthma, there is high-quality evidence for medication reduction while maintaining symptom control; evidence for HDM SLIT efficacy in allergic rhinitis is of moderate-low quality. There is moderate evidence for efficacy of dual grass pollen-HDM SLIT after 12 months of treatment and 1 year after discontinuation. Specific provocation test results (nasal, skin) improve with grass pollen and HDM SLIT but nonspecific bronchial provocation testing does not. Food oral immunotherapy is more promising than food SLIT. Possible new surrogate markers have been reported. No anaphylaxis was found among 2469 treated children.

CONCLUSION

Evidence for efficacy of SLIT in children with respiratory or food allergy is growing.

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.

Perspectives on allergen-specific immunotherapy in childhood: an EAACI position statement

This article is the result of consensus reached by a working group of clinical experts in paediatric allergology as well as representatives from an ethical committee and the European Medicine Agency (EMA). The manuscript covers clinical, scientific, regulatory and ethical perspectives on allergen-specific immunotherapy in childhood. Unmet needs are identified. To fill the gaps and to bridge the different points of view, recommendations are made to researchers, to scientific and patient organizations and to regulators and ethical committees. Working together for the benefit of the community is essential. The European Academy of Allergy and Clinical Immunology (EAACI) serves as the platform of such cooperation.