The appropriate use of skin testing and allergen immunotherapy in young children

Quality-of-life outcomes in patients who underwent subcutaneous immunotherapy and sublingual immunotherapy in a real-world clinical setting

OBJECTIVE

To compare changes in quality of life (QOL) that resulted from sublingual immunotherapy (SLIT) and subcutaneous immunotherapy (SCIT) in a real-world clinical setting.

BACKGROUND

SLIT is established as a viable alternative to SCIT for the treatment of allergic rhinitis. Although comparative trials are increasingly available, few studies have examined QOL outcomes between these two treatments.

METHODS

One hundred and five participants who underwent immunotherapy for airborne allergies were enrolled in this prospective, single-center study. Forty participants completed the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) at initiation of therapy, after 6 months, and after 1 year of therapy. Only patients with complete time points were included in the ultimate analysis. Twenty-nine of these participants underwent SCIT and 11 underwent SLIT. The effects of age, sex, and asthma history were also examined.

RESULTS

The participants in both groups demonstrated improvements in QOL regarding allergic rhinoconjunctivitis over the study period. However, the change in the RQLQ score from both baseline to 6 months and baseline to 1 year was only statistically significant in the SCIT group (p = 0.002, 6 months and 1 year). The participants in the SCIT group also demonstrated statistically significant improvement from baseline to 1 year in the specific domains of practical and emotional functioning, nasal symptoms, non-nasal/eye symptoms, and sleep. After 1 year, both SCIT and SLIT demonstrated a minimally important difference from baseline in the overall RQLQ score. Age <35 years in the SCIT group had a significant positive impact on QOL improvement (p = 0.038).

CONCLUSION

Although improvements in QOL were noted in both groups, changes in overall scores and the majority of domains only achieved statistical significance in the SCIT group. A small study population and difficulties adhering to immunotherapy dosing schedules in the SLIT group may be contributing factors.

Sublingual immunotherapy in preschool children: an update

Allergen immunotherapy is a subject widely debated by allergists. Currently, there are controversial discussions focused on the sublingual route. Sublingual immunotherapy (SLIT) has so far been used in Europe, Asia and Australia for the treatment of allergic respiratory diseases. The minimum age to start specific immunotherapy with inhalant allergens in children has not been clearly established, and position papers discourage its use in children younger than 5 years of age. Nevertheless, it is known that SLIT efficacy is higher when SLIT is started at an earlier age. The aim of this review is to focus on studies in preschool children evaluating SLIT safety and efficacy, in order to improve this practice at an earlier age in childhood.

Cytotoxic T lymphocyte antigen 4-immunoglobulin G is a potent adjuvant for experimental allergen immunotherapy

Allergen-specific immunotherapy (SIT) is the only treatment for allergic diseases that targets allergen-specific T helper type 2 (Th2) cells, which are the cause of the disease. There is an unmet requirement for adjuvants that increase the clinical efficacy of SIT allowing application of lower doses of the allergen, thereby reducing the risk of anaphylactic reactions. Cytotoxic T lymphocyte antigen 4-immunoglobulin (CTLA-4-Ig) has been shown to induce immunological tolerance in autoimmunity and allograft transplantation by blocking T cell co-stimulation and induction of the immunoregulatory enzyme indoleamine 2,3 dioxygenase (IDO). Previously, we showed that CTLA-4-Ig treatment at the time of allergen inhalation induced tolerance to subsequent allergen exposure in a mouse model of asthma. In this study, we test the hypothesis that CTLA-4-Ig acts as an adjuvant for experimental SIT. We evaluated the adjuvant effects of CTLA-4-Ig on SIT in a mouse model of ovalbumin-driven asthma. We used both wild-type and IDO-deficient mice to assess the role of IDO in the adjuvant effects of CTLA-4-Ig. Co-administration of CTLA-4-Ig strongly increased SIT-induced suppression of airway hyperreactivity (AHR), specific IgE in serum, airway eosinophilia and Th2 cytokine levels. Moreover, we found that CTLA-4-Ig, as an adjuvant for SIT, is equally effective in IDO-deficient and wild-type mice, demonstrating that the effect of CTLA-4-Ig is independent of IDO expression. We show that CTLA-4-Ig acts as a potent adjuvant to augment the therapeutic effects of SIT. As the adjuvant activity of CTLA-4-Ig is independent of IDO, we conclude that it acts by blocking CD28-mediated T cell co-stimulation.

Safety of specific immunotherapy using a depigmented and polymerised extract of Dermatophagoides pteronyssinus in children under five years of age

BACKGROUND

Different opinion documents point to a patient age of under five years as a relative contraindication to specific immunotherapy, arguing that this age group has a greater risk of developing anaphylaxis, and that specially trained personnel are needed to deal with the problem if it occurs. However, insufficient evidence exists to support such an affirmation.

PATIENTS AND METHODS

A retrospective follow-up observational study was made of patients aged 60 months or younger who had been subjected to specific immunotherapy. We included 77 children with a diagnosis of extrinsic bronchial asthma (n=68), extrinsic spasmodic cough (n=5) and allergic rhinitis (n=4) confirmed by clinical criteria and prick-test, with specific IgE positivity to Dermatophagoides pteronyssinus. All patients received specific immunotherapy with an extract of depigmented D. pteronyssinus polymerised with glutaraldehyde, involving an initial cluster protocol of two weeks and monthly maintenance doses. All observed adverse reactions were recorded, and classified according to European Academy of Allergy and Clinical Immunology (EAACI) criteria.

RESULTS

A total of 1837 doses were administered to the 77 patients, with four adverse reactions being observed in three patients. Three reactions (0.16% of the administered doses) were local and immediate, while one was systemic and of grade 2 (0.05% of the administered doses) - consisting of an episode of nocturnal wheezing.

CONCLUSIONS

Specific immunotherapy in children under five years of age with the extract used is safe. We consider that further studies are needed, involving other types of extracts, to allow reconsideration of the relative contraindication of patient age for the administration of immunotherapy.

Subcutaneous injection immunotherapy for optimal effectiveness

Immunotherapy by the subcutaneous injection of increasing doses and then maintenance doses of extracts of inhalant allergens has been practiced for 100 years. Controlled clinical trials have established its efficacy in treating allergic rhinitis, asthma, and stinging insect sensitivity, and there are preliminary data to suggest a favorable response in some patients with atopic dermatitis. The response to subcutaneous injection immunotherapy is dose dependent. Disease-modifying actions include blocking development of new sensitivities in monosensitized patients, blocking progression to asthma in patients with allergic rhinitis, and persistence of treatment effects for up to 7 to 10 years after an initial course.

The anti-vaccination movement and resistance to allergen-immunotherapy: a guide for clinical allergists

Despite over a century of clinical use and a well-documented record of efficacy and safety, a growing minority in society questions the validity of vaccination and fear that this common public health intervention is the root-cause of severe health problems. This article questions whether growing public anti-vaccine sentiments might have the potential to spill-over into other therapies distinct from vaccination, namely allergen-immunotherapy. Allergen-immunotherapy shares certain medical vernacular with vaccination (e.g., allergy shots, allergy vaccines), and thus may become "guilty by association" due to these similarities. Indeed, this article demonstrates that anti-vaccine websites have begun unduly discrediting this allergy treatment regimen. Following an explanation of the anti-vaccine movement, the article aims to provide guidance on how clinicians can respond to patient fears towards allergen-immunotherapy in the clinical setting. This guide focuses on the provision of reliable information to patients in order to dispel misconceived associations between vaccination and allergen-immunotherapy, and the discussion of the risks and benefits of both therapies in order to assist patients in making autonomous decisions about their choice of allergy treatment.

Looking ahead at the potential benefits of biotechnology-derived allergen therapeutics

While biotechnology-derived allergen therapeutics show promise in improving the safety of immunotherapy, they may prove to have additional benefits in comparison to conventional allergenic extracts that deserve commentary. These issues range from product stability and compatibility to medical practice issues, which will be the focus of this article.

Assessment of childhood allergy for the primary care practitioner

PURPOSE

To update the primary care practitioner on the assessment of common childhood allergic illnesses.

DATA SOURCES

Relevant scientific literature and published clinical practice guidelines.

CONCLUSIONS

Atopic children often develop symptoms that occur in a predictable progression from atopic dermatitis to gastrointestinal disturbances, chronic serous otitis media, rhinitis, and asthma. Evaluation of allergic symptoms should be based on their chronicity, family history of atopy, and knowledge of how the information will change patient management. Both skin and blood testing are accurate and useful tools in establishing a diagnosis of allergic disease. Management includes avoidance/environmental control, medications, and, when necessary, referral to specialists.

IMPLICATIONS FOR PRACTICE

As the incidence of allergic disease increases, the human and monetary costs associated with allergies place a major burden on our healthcare system. Early identification of allergies and appropriate intervention are important to prevent progression to more significant disease. The use of objective diagnostic testing aids in implementing appropriate evidence-based medical management.

Pollen immunotherapy: selection,prevention, and future directions

Pollens are an important cause of allergic rhinitis and asthma. Pollen immunotherapy is effective and potentially curative. It has been shown to prevent new sensitizations, to prevent the development of asthma in children, and to induce long-term benefit. Standardization of allergen extracts is necessary to improve immunotherapy safety and efficacy. Knowledge of the local plant taxonomy and allergen cross-reactivity is important in selecting clinically relevant vaccines. In general, allergenic cross-reactivities correspond to taxonomic relations. Tree and weed species demonstrate variable degrees of cross-reactivity. Most grasses have extensive allergenic cross-reactivity. Mechanism of action continues to be an area of investigation, including the induction of immunoglobulin G blocking antibodies. Sublingual immunotherapy, concurrent anti-immunoglobulin E use, hypoallergic peptides, and DNA vaccines are other promising technologies.

Safety of sublingual-swallow immunotherapy in children aged 3 to 7 years

BACKGROUND

The minimum age to start specific immunotherapy with inhalant allergens in children has not been clearly established, and position papers discourage its use in children younger than 5 years.

OBJECTIVE

To assess the safety of high-dose sublingual-swallow immunotherapy (SLIT) in a group of children younger than 5 years.

METHODS

Sixty-five children (51 boys and 14 girls; age range, 38-80 months; mean +/- SD age, 60 +/- 10 years; median age, 60 months) were included in this observational study. They were treated with SLIT with a build-up phase of 11 days, culminating in a top dose of 300 IR (index of reactivity) and a maintenance phase of 300 IR 3 times a week. The allergens used were house dust mites in 42 patients, grass pollen in 11 patients, olive pollen in 5 patients, Parietaria pollen in 4 patients, and cypress pollen in 3 patients. All adverse reactions and changes in the treatment schedule were compared in 2 subgroups: children 38 to 60 months old and children 61. to 80 months old.

RESULTS

The average cumulative dose of SLIT was 36,900 IR. Adverse reactions were observed in 11 children, none of them severe enough to require discontinuation of immunotherapy. Six reactions occurred in the 60 months or younger age group and 7 in the older than 60 months age group, with no differences between these 2 groups.

CONCLUSION

High-dose immunotherapy in children younger than 5 years does not cause more adverse reactions than in children aged 5 to 7 years. There is no reason to forbear studies on safety and efficacy of these preparations in young children.

Allergen immunotherapy in the prevention of asthma

PURPOSE OF REVIEW

Asthma is a disease causing significant morbidity and mortality. In the recent past, there has been an explosion of pharmacotherapeutic options attempting to control the disease. Unfortunately, none of the current options offers the promise of prevention or a permanent cure. However, there appear to be exciting, new data emerging to support the hypothesis that the prevention or early treatment of allergic rhinitis, such as with the use of allergen immunotherapy, may help mitigate the severity of bronchial symptoms and even prevent the development of asthma. In this paper, we review recent research published proposing immunotherapy as a means of preventing the development of, or at least ameliorating, allergic asthma.

RECENT FINDINGS

There is evidence that the upper and lower airways may be considered a single unit, with the nasal and bronchial mucosa having features in common. Epidemiological, pathophysiological and clinical studies have shown that they can be affected by similar inflammatory triggers, with interconnected mechanisms amplifying the inflammatory cascade. Allergic rhinitis is interrelated to, and is a risk factor for, the development of asthma. An evidence-based review validates the successful use of allergen immunotherapy in treating allergic rhinitis and asthma. There is promising evidence advocating its use in the prevention of clinical asthma.

SUMMARY

This article explores current research pertaining to the use of immunomodulation, such as by using allergen immunotherapy, to ameliorate and prevent the development of allergic asthma.

Prevention of new sensitizations in asthmatic children monosensitized to house dust mite by specific immunotherapy. A six-year follow-up study

BACKGROUND

Specific immunotherapy (SIT) is a recognized way of treating IgE-mediated respiratory diseases. The clinical outcome is usually better in allergic children than in adults.

OBJECTIVE

To increase our knowledge of the ability of SIT to prevent the onset of new sensitizations in monosensitized subjects, so far poorly documented.

METHODS

134 children (age range 5-8 years), who had intermittent asthma with or without rhinitis, with single sensitization to mite allergen (skin prick test and serum-specific IgE), were enrolled. SIT was proposed to all the children's parents, but was accepted by only 75 of them (SIT Group). The remaining 63 children were treated with medication only, and were considered the Control Group. Injective SIT with mite mix was administered to the SIT Group during the first three years and all patients were followed for a total of 6 years. All patients were checked for allergic sensitization(s) by skin prick test and serum-specific IgE every year until the end of the follow-up period.

RESULTS

Both groups were comparable in terms of age, sex and disease characteristics. 123 children completed the follow-up study. At the end of the study, 52 out of 69 children (75.4%) in the SIT Group showed no new sensitization, compared to 18 out of 54 children (33.3%) in the Control Group (P < 0.0002). Parietaria, Gramineae and Olea were the most common allergens responsible for the new sensitization(s).

CONCLUSIONS

According to our data, SIT may prevent the onset of new sensitizations in children with respiratory symptoms monosensitized to house dust mite (HDM).

Specific immunotherapy in rhinitis and asthma

OBJECTIVE

The primary objective of this review is to discuss the efficacy of immunotherapy on combined lung and nasal symptoms, as well as data suggesting that allergen-specific immunotherapy (SIT) may, by altering the natural course of allergic disease, have a preventive effect on rhinitis and asthma.

DATA SOURCES

A review of literature published on allergen-specific immunotherapy in the treatment of allergic rhinitis and asthma was performed. The review represents a synthesis of these sources and the expert opinion of the author.

STUDY SELECTION

The expert opinion of the authors was used to select the relevant data for the review.

RESULTS

Epidemiologic studies have consistently shown that asthma and rhinitis often co-exist in the same patients, and rhinitis often precedes the onset of asthma. SIT has been shown to be effective as a curative treatment for these allergic diseases, but there is increasing evidence indicating that SIT also may have a preventive effect. A study of children monosensitized to house dust mites showed that immunotherapy altered the natural course of allergy in preventing the development of additional sensitizations.

CONCLUSIONS

At present, SIT seems to be the only treatment that may modify the course of the disease, either by preventing the development of new sensitivities or by altering the natural history of asthma. When SIT is introduced to patients with only allergic rhinoconjunctivitis, it may stop the development of asthma. SIT should be started early in the disease process, as soon as allergy has been diagnosed, to modify the spontaneous long-term progress of the allergic inflammation and disease.

Allergic rhinitis. Outcomes of immunotherapy on symptom control

Recent scientific studies have demonstrated the efficacy of various forms of immunotherapy for the treatment of allergic diseases. Traditional subcutaneous immunotherapy, sublingual, oral, and intranasal immunotherapy have been shown to significantly reduce symptoms and favorably modulate the immune response. Outcome studies that use patient response data from standardized surveys represent the next challenge to all practicing allergists.

In vivo and in vitro testing for adverse drug reactions

The goal of providing an accurate and reliable diagnostic test for the evaluation of adverse drug reactions remains elusive. Rechallenge remains a truly conclusive method for determining the contribution of drugs to adverse effects, but there are significant disadvantages in exposing patients to drugs that may have caused serious adverse effects. Skin tests are useful for the assessment and predictive risk of serious adverse reactions for a small number of drugs, but skin tests are limited in their utility to adverse drug reactions mediated by Type 1 hypersensitivity. Skin tests must be performed with care and rigor as well. There are a number of in vitro assays that have been used for the assessment of adverse drug reactions, but many of these assays are primarily research tools and have little utility in the clinical setting. Although in vitro tests are not yet readily available for the diagnosis of adverse drug reactions, our increasing understanding of the biology of adverse drug reactions and interactions between the immune system and xenobiotics offers promise that more clinically relevant assays can be developed. At the present time, the primary diagnostic tools for the assessment of adverse drug reactions remain a careful history and physical examination and an astute, insightful physician.

Immunotherapy for childhood asthma: is there a rationale for its use?

OBJECTIVE

This paper reviews the literature regarding immunotherapy in the management of childhood asthma. Immunotherapy is a well established treatment of venom allergy and allergic rhinitis, however its use in asthma remains controversial.

DATA SOURCES

We reviewed the pediatric literature from 1966 to 1994 and evaluated the existing studies for clinical efficacy of immunotherapy in childhood asthma.

STUDY SELECTION

Only 12 purely pediatric studies existed over the time period that we reviewed. The studies used a variety of different antigens including house dust, house dust mite, grass, mold, cat, dog, and combinations of antigens.

RESULTS

In reviewing the studies, we assessed study duration, number of subjects, whether it was blinded, placebo controlled or open labeled, the measures of clinical efficacy and the assessments of specific and nonspecific bronchial reactivity. The studies were very heterogeneous, and therefore direct comparison and extrapolation of conclusions was difficult. The majority of the studies demonstrated either an improvement in asthmatic symptoms or a decrease in bronchial reactivity to the specific antigen employed, or both. The minority of studies demonstrated no clinical efficacy. The most consistent evidence of benefit was suggested in those trials employing house dust mite therapy, while immunotherapy for grass and cats demonstrated some benefit but the number of studies employing these treatments was very small. There are no trials that provide convincing evidence that immunotherapy with dog and mold antigens is effective for childhood reactive airway disease.

CONCLUSION

Asthma is a multifactorial disease with many triggers. In establishing a role for immunotherapy one must consider all the different aspects such as allergic triggers, environmental stresses, and viral infections. The literature is unclear as to when immunotherapy should be initiated for childhood asthma. While there are suggestions that immunotherapy should be considered for the child with mild or moderate asthma and dust mite sensitivity when pharmacotherapy is not efficacious, the immunomodulatory properties of immunotherapy may actually be more tailored for early intervention in asthma rather than for use once symptoms have occurred. More research is required in order to clarify whether immunotherapy should be recommended more often for the treatment of childhood asthma.