Specific immunotherapy is effective in the prevention of new sensitivities

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.

A real-world retrospective study of safety, efficacy, compliance and cost of combination treatment with rush immunotherapy plus one dose of pretreatment anti-IgE in Chinese children with respiratory allergies

Background

The efficacy of allergen immunotherapy (AIT) in treating pediatric allergy has been clearly demonstrated, however, many patients hesitate to initiate AIT due to weekly hospital visits during the 3-4 months up-dosing phase. Meanwhile, rush immunotherapy (RIT) shortens the duration of the up-dosing phase to 7 days. However, considering that patients receiving RIT are exposed to the allergens during a much shorter period of time and thus may be at a greater risk of systemic reactions, RIT is currently underused, especially in children. This study investigated the utility of combination treatment with RIT plus 1 dose of pretreatment anti-IgE in children with respiratory allergies.

Methods

In this retrospective study, we reviewed records of children with allergic rhinitis (AR) and/or allergic asthma (AA) sensitized to dust mite allergens receiving RIT+1 dose of pretreatment anti-IgE (the RIT group) or conventional immunotherapy (the CIT group) at our hospital from January 2020 to March 2021. Data such as visual analogue scale (VAS) scores, comprehensive symptom and medication score (CSMS), allergy blood test results, adverse reactions, compliance and cost were collected and analyzed.

Results

40 patients in the RIT group and 81 patients in the CIT group were included in this study. Both treatments were well tolerated and patients in the 2 treatment groups had comparable local and systemic reactions. Compared to CIT, RIT + anti-IgE combination led to significantly faster symptomatic improvement as demonstrated by significantly decreased VAS and CSMS starting as early as 1 month after AIT initiation (P<0.05). Nobody dropped out in the RIT group during the 1 year follow-up, while 11 out of 81 patients in the CIT group dropped out (loss rate 13.5%). Thus, the RIT group had a significantly higher compliance rate than the CIT group (P<0.05). Finally, the 2 treatment regimens had comparable cost per patient per injection (P> 0.05).

Conclusions

RIT + 1 dose of pretreatment anti-IgE combination has practical advantages over CIT, including comparable safety, better compliance, and probably a faster onset of clinical efficacy at no additional cost, so it can be an useful regimen for the treatment of Chinese children with respiratory allergies.

The Effect of Allergen Immunotherapy on the Development of New Sensitization in Children

Aim

The protective effect of allergen immunotherapy against a new allergic sensitization is controversial. This study aimed to investigate the effect of allergen immunotherapy on new allergic sensitization in children.

Materials and Methods

The study included 50 patients who received immunotherapy for at least 3 years, and whose skin prick tests were repeated at intervals of at least 3 years (31 patients for house dust mite immunotherapy, 19 patients for pollen immunotherapy), and 69 controls with similar characteristics.

Results

The number of patients who developed a new sensitization was similar both in the groups of patients who received house dust mite and pollen immunotherapy, and the control group. There was no significant difference between the first and last skin prick tests of the patients who received house dust mite and pollen immunotherapy; however, in the control groups, a significant increase in sensitivity to tree pollens (n = 2, 5.4%; n = 8, 21.6%) and weed pollens (n = 7, 26.9%; n = 14, 53.8%) was detected (P = .031 and P = .039). While allergen sensitivities in the first tests of the pollen immunotherapy group and the control group were similar, weed pollen sensitivity was significantly higher in the last tests of the control group (n = 14, 53.8%; n = 4, 21.1%, P = .027). It was determined that the presence of weed pollen sensitization (OR: 8.1, 95% CI: 1.5-42.4) and having asthma (OR: 3.5, 95% CI: 1.3-10.8) increases the risk of new sensitization in all groups.

Conclusion

Allergen immunotherapy has been found to protect against new sensitization to tree and weed pollens. However, this effect was insignificant in the multivariate analysis. Weed pollen sensitization and the presence of asthma are related to the development of new sensitization.

Safety and Utility of Rush Immunotherapy with Aqueous Allergen Extracts for Treatment of Respiratory Allergies

BACKGROUND

Generally, allergen immunotherapy must be administered for three to five years. Meanwhile, rush immunotherapy (RIT) shortens the required duration for the build-up phase, thereby improving the therapy's convenience compared with conventional immunotherapy (CIT). However, RIT is often performed with modified allergens. Therefore, this study aimed to investigate the safety and utility of RIT with aqueous allergens.

METHODS

Medical records of 98 patients sensitized with at least one inhalant allergen who had received subcutaneous immunotherapy for allergic rhinitis with or without asthma were retrospectively reviewed. All patients were classified into three groups: depot-RIT (n = 25), receiving RIT with depot allergen; aqueous-RIT (n = 48), receiving RIT with aqueous allergen; and aqueous-CIT (n = 25), receiving CIT with aqueous allergen. Patients who had received immunotherapy targeting only house dust mites were excluded.

RESULTS

The proportions of patients presenting with a systemic reaction to depot-RIT, aqueous-RIT, or aqueous-CIT were 80.0%, 85.4%, and 48.0%, respectively (P = 0.002). The proportions of patients experiencing severe systemic reaction were 4.0%, 16.7%, and 8.0% in depot-RIT, aqueous-RIT and aqueous-CIT, respectively (P = 0.223). The proportions of depot-RIT and aqueous-RIT patients presenting with systemic reaction or severe systemic reaction did not differ significantly (P = 0.553 and P = 0.118, respectively). Significantly fewer depot-RIT (1.0 ± 0.2) and aqueous-RIT patients (2.0 ± 1.3) required outpatient clinical visits during the build-up phase, compared to those administered aqueous-CIT (13.6 ± 1.9; P < 0.001). Moreover, the build-up phase decreased to 17.4 ± 1.8 days in depot-RIT and 23.7 ± 10.9 days in aqueous-RIT, compared to 92.0 ± 12.5 days in aqueous-CIT (P < 0.001).

CONCLUSION

RIT with aqueous allergen reduced the build-up phase duration and frequency of hospital visits, with acceptable safety levels. RIT with aqueous allergen may, therefore, be suitable for broad application to patients with respiratory allergies.

Does new sensitization correlate with nasal symptoms in children with allergic rhinitis?

OBJECTIVES

To evaluate the correlation between the increased number of sensitized allergens and nasal symptoms in patients with allergic rhinitis who were sensitized to house dust mites (HDMs).

METHODS

Among the patients who were enrolled in the Allergic Rhinitis Cohort Study for Kids, 174 children with rhinitis symptoms who were sensitized to HDMs were included in the analysis. Skin prick tests, serum total immunoglobulin E, eosinophil count, and bronchial provocation tests were carried out during the initial and 3-year follow-up visits. The patients were divided into two groups depending on the change in the number of sensitized allergens: increased number of sensitized allergens (group I) and maintained or reduced number of sensitized allergens (group II).

RESULTS

In the analysis of allergen sensitization from baseline to the 3-year follow-up, no significant correlation was observed between the changes in the number of allergens and the total nasal visual analog scale score (R²  < 0.001, P = .813). Furthermore, the comparison of demographic data and immunological factors between groups I and II did not show any significant differences. The changes in bronchial hyper-responsiveness were not significantly different between the two groups (P = 1.000).

CONCLUSION

New sensitization may not be correlated with nasal symptoms in patients in Asian countries where HDMs play a major role as a dominant allergen. Although further investigation must be conducted, the importance of new sensitization as an indicator of treatment outcome should be reconsidered in individuals in Asia.

LEVEL OF EVIDENCE

2b Laryngoscope, 130: 1864-1871, 2020.

Clinical Efficacy of Allergen-Specific Immunotherapy from Patient and Physician Perspectives

PURPOSE

Allergen-specific immunotherapy (AIT) is the only curative treatment for allergic diseases, but a few allergic patients receive AIT. In this multicenter cross-sectional study, we aimed to explore patient and physician perspectives on AIT through a questionnaire survey.

MATERIALS AND METHODS

Allergic patients who received subcutaneous immunotherapy for at least 1 year were asked to answer a questionnaire developed by an expert panel of allergen and immunotherapy workgroup in Korea.

RESULTS

A total of 267 patients (adults, 60.3%) with allergic rhinitis (91.4%), asthma (42.7%), or atopic dermatitis (20.2%) from referred hospitals completed the survey. Among patients and physicians, respectively, the overall rates of satisfaction with AIT for allergic rhinitis were 86.4% and 83.3% (kappa agreement=0.234, p<0.001), and those for asthma were 85.3% and 72.9% (kappa agreement=0.373, p<0.001). Moreover, pediatric asthmatic patients reported a significantly higher satisfaction rate than adult asthmatic patients after AIT (p=0.040). Symptom severity (p<0.001, respectively) and drug use for allergic rhinitis and asthma decreased after AIT. However, there was no significant difference in satisfaction rates between children and adults in allergic rhinitis (p=0.736). Interestingly, 35.7% and 35% of allergic rhinitis and asthma patients, respectively, reported experiencing improvement in their symptoms within 6 months of starting AIT.

CONCLUSION

In this study evaluating the perspectives of patients and physicians on AIT, the majority of patients were satisfied with the efficacy and safety of AIT, but not its cost. AIT should be recommended for AR and allergic patients.

Preventing new sensitization and asthma onset by allergen immunotherapy: the current evidence

PURPOSE OF REVIEW

Specific allergen immunotherapy is considered a key candidate for a successful preventive intervention in atopic diseases. The strong association of atopic manifestations such as rhinitis and asthma with atopic sensitizations (specific serum IgE) provide a rationale for early intervention in childhood and adolescence.

RECENT FINDINGS

Currently, the documentation of the disease-modifying intervention effects is limited to the secondary prevention of asthma symptoms in children with allergic rhinoconjunctivitis. These effects appear to be rather allergen specific than nonspecific.

SUMMARY

Documentation on disease modification including a reduction of asthma symptoms in children, particularly with grass pollen tablets has become quite robust. It is not clear up to now, if the new onset of allergic sensitizations can be modified. So far data on primary prevention are not conclusive.

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.

Chinese Guideline on allergen immunotherapy for allergic rhinitis

The present document is based on a consensus reached by a panel of experts from Chinese Society of Allergy (CSA) and Chinese Allergic Rhinitis Collaborative Research Group (C2AR2G). Allergen immunotherapy (AIT), has increasingly been used as a treatment for allergic rhinitis (AR) globally, as it has been shown to provide a long-term effect in improving nasal and ocular symptoms, reducing medication need, and improving quality of life. AIT is currently the only curative intervention that can potentially modify the immune system in individuals suffering from AR and prevent the development of new sensitization and the progression of disease from AR to asthma. Although the use of AIT is becoming more acceptable in China, to date no AR immunotherapy guideline from China is available for use by the international community. This document has thus been produced and covers the main aspects of AIT undertaken in China; including selection of patients for AIT, the allergen extracts available on the Chinese market, schedules and doses of allergen employed in different routes of AIT, assessment of effect and safety, patients' administration and follow-up, and management of adverse reactions. The Chinese guideline for AR immunotherapy will thus serve as a reference point by doctors, healthcare professionals and organizations involved in the AIT of AR in China. Moreover, this guideline will serve as a source of information for the international community on AIT treatment strategies employed in China.

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.

Allergy immunotherapy: what is the evidence for cost saving?

PURPOSE OF REVIEW

Given the widespread prevalence of allergic disease, its substantially associated clinical and economic burden, the unique disease-modifying benefits of allergy immunotherapy (AIT), and increased availability of sublingual immunotherapy (SLIT), a critical update of the evidence for AIT-related cost savings [for both subcutaneous immunotherapy (SCIT) and SLIT] is particularly relevant and timely. The present article reviews the evidence for SCIT-related and SLIT-related cost savings derived from a systematic review of the published literature.

RECENT FINDINGS

Examined were 24 publications pertaining to the health economics of AIT. Except for one early study comparing the costs of AIT to symptomatic drug treatment (SDT), the remainder provide compelling evidence for AIT cost savings (whether SCIT or SLIT) over SDT. Furthermore, of the six studies comparing cost outcomes of SLIT to SCIT, four reported cost savings favoring SLIT.

SUMMARY

This review, spanning research from Southern Europe, Scandinavia, Northern Europe, North America, and the Czech Republic, encompasses a range of perennial and seasonal allergic conditions, including allergic asthma, allergic rhinitis with or without asthma, and rhinoconjunctivitis with or without allergic rhinitis due to house dust mite, grass or ragweed pollen, or a mixture of various allergens. All but one study compellingly demonstrate cost savings conferred by AIT over SDT.

A survey of the prescription patterns of allergen immunotherapy in Korea

Purpose

Allergen immunotherapy (AIT) has been used as a curative and specific treatment of allergic diseases. However, no data on the prescription patterns of AIT in Korea is available. Therefore, we surveyed the prescription patterns of AIT by allergy specialists in Korea.

Methods

We emailed a questionnaire on AIT prescription patterns to the 690 members of the Korean Academy of Asthma, Allergy and Clinical Immunology with clinical practice experience. All returned answers were evaluated.

Results

The response rate was 21.0%. Only 69.0% of the respondents performed AIT in practice. Hindrance factors for performing AIT in the practice included a lack of facilities (21%), lack of practical experience during their subspecialty or postgraduate educational training programs (15.8%), no need for AIT because of sufficient pharmacotherapy (14.5%), insufficient economic profits (14.5%), and risks for adverse reactions (13.2%). Ninety-two allergy specialists (82%) performed AIT subcutaneously subcutaneous immunotherapy (SCIT) and 20 allergy specialists (18%) performed it sublingually sublingual immunotherapy (SLIT). Only 8 specialists performed both SCIT and SLIT. The allergens used for SCIT were house dust mites (98.9%), pollens (72.8%), and animal dander (23.9%). SLIT was prescribed only for house dust mites. Twenty-eight physicians (30.4%) observed anaphylactic reactions during SCIT. Eight physicians (40.0%) who prescribed SLIT observed adverse reactions, including local reactions, but none of them observed anaphylactic reactions.

Conclusions

In this survey, 69.0% of the respondents performed AIT in clinical practice. SCIT prescription is more popular than SLIT. The Lack of facilities and clinical education is a critical barrier to performing AIT. Therefore, proper clinical education of AIT is necessary for Korean allergists.

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.

One hundred years of allergen immunotherapy European Academy of Allergy and Clinical Immunology celebration: review of unanswered questions

Allergen immunotherapy was introduced by Leonard Noon 100 years ago and is the only disease-modifying treatment for allergic individuals. Improved understanding of immunology has taught us a great deal about the underlying mechanisms involved in allergen immunotherapy; however, despite these developments, a number of important questions remain unanswered. Several of these questions relate to the practice of allergen immunotherapy in the clinic, such as: Is it possible to unify units of allergen potency? Which treatment schedules are best? Is allergen immunotherapy effective in all patient groups? Is there a dose-response relationship for efficacy and safety?, and Is there evidence for long-term effects following allergen immunotherapy? Others are related to new developments, such as new indications, or developments in the production of allergens. On the centenary of Noon's discovery, European experts in the field of immunotherapy met in Geneva under the aegis of the EAACI to discuss these controversial issues. This study presents outcomes and conclusions from these discussions.

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

OBJECTIVE

To update the scientific evidence of subcutaneous immunotherapy (SCIT) in children.

DATA SOURCES

PubMed, EMBASE, and known articles.

STUDY SELECTION

All publications on SCIT in pediatric patients from January 2006 to April 2011. Study design was not a restriction. The articles were analyzed according to their outcomes and evaluated on their scientific quality using the Grading of Recommendations Assessment, Development, and Evaluation and Jadad tools. Clinical, safety, and immunologic data were gathered.

RESULTS

The scientific evidence produced by the 31 articles analyzed showed that there is high-quality evidence that grass pollen SCIT causes a reduction in the combined symptom-medication score and increases the threshold of the conjunctival provocation test, immediately and 7 years after termination of SCIT, as well as the threshold of the specific bronchial provocation test and the skin prick test reactivity. Alternaria SCIT improves medication scores, combined symptom-medication scores, and quality of life. It augments the threshold in the nasal provocation test. High-quality evidence of house dust mite SCIT shows that asthma symptom and medication scores improve and emergency department visits and skin reactivity are reduced; moderate evidence indicates improvement in pulmonary function tests. Pollen SCIT prevents asthma (moderate evidence); evidence for long-term benefit of pollen SCIT (7-12 years after termination) is low to moderate. There is inconclusive evidence for SCIT reducing new sensitizations.

CONCLUSION

There is acceptable evidence that shows that grass pollen, Alternaria, and house dust mite SCIT is beneficial in allergic children.

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.

Efficacy and safety of a glutaraldehyde-modified house dust mite extract in allergic rhinitis

BACKGROUND

Modification of allergens by glutaraldehyde in extracts used for immunotherapy reduces the risk for side effects, but therapeutic efficacy of such extracts requires further evaluation. The aim of this study was to evaluate the efficacy and safety of immunotherapy with PURETHAL Mites (PM), a single-strength glutaraldehyde-modified aluminum hydroxide-adsorbed extract of house-dust mites (HDM).

METHODS

In a multicenter, randomized, placebo-controlled double-blind setting, HDM-allergic subjects (n = 140) were treated with modified allergen extract or placebo over a 1-year period. The primary outcome parameter was a combined symptom and medication score (clinical index score [CIS]). Secondary efficacy parameters were the result of a titrated conjunctival provocation test (CPT), rhinitis/rhinoconjunctivitis quality of life (RQL) score, and serum concentrations of IgE and IgG against specific HDM allergens and a documentation of adverse events (AE).

RESULTS

We evaluated 140 patients (66 treatment and 74 placebo) for clinical efficacy. The allergoid treatment for 1 year resulted in significantly greater CIS improvement and higher RQL scores. The response threshold in the titrated CPT (p = 0.009) and the serum concentrations of IgG4 (p < 0.001) against Dermatophagoides pteronyssinus allergens after treatment were also significantly different between groups. In total, 88 patients (46 PM/42 placebo) out of a safety population of 145 reported 278 (158 PM/120 placebo) AE. Except for local reactions, no specific AE appeared to be associated with PURETHAL Mites (HAL-Allergy, Leiden, The Netherlands).

CONCLUSION

The findings of this study indicate that allergen injection therapy with modified HDM extract is superior to placebo in allergic rhinitis therapy. The treatment was well tolerated and no serious drug-related AE were observed.

Clinical practice: Allergen-specific immunotherapy in children: facts and FAQs

Allergen-specific immunotherapy (SIT) in its various application forms represents the main treatment approach of IgE-mediated allergic diseases in adults and children. Despite this clear recommendation, many particularities of products, patient characteristics, and product availability in different countries hamper the use of allergen-specific immunotherapy in particular in children. The frequently asked questions by parents, patients, and physicians are the backbone of this review. Thus, the potentials and limitations of allergen-specific immunotherapy in children and adolescents will be highlighted. IgE-mediated allergic diseases are affecting about 20% of the population. They manifest commonly early in life, and hence, the use of SIT should be considered also early in the course of the disease.

[Secondary and tertiary prevention of allergic asthma in children]

Asthma is a disease of the lung epithelial barrier, most often associated with allergy in children. Asthma and allergy are two distinct diseases, but the phenotypic expression of asthma depends on atopic status. A better definition of phenotypes of asthma would result in better targeting of prevention and treatment modalities. Secondary prevention aims to prevent the onset of asthma and the acquisition of new sensitizations in sensitized children. Studies concerning allergen avoidance are insufficient to reach a definitive conclusion and antihistamines have not been shown to be effective. The results for specific immunotherapy suggest a benefit to prevent transition from allergic rhinitis to asthma and the onset of new sensitizations. Tertiary prevention aims to reduce symptoms in children with an existing allergic asthma diagnosis. The avoidance of known respiratory allergens will only be effective in combination with management of the whole environment. Specific immunotherapy has a real place, in combination with background therapy. It should be used according to guidelines in appropriately treated patients.

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

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

The role of indoor allergens in the development of asthma

PURPOSE OF REVIEW

Asthma prevalence has markedly increased over the past 30 years. Although atopy and exposure to environmental allergens are known to exacerbate asthma, recent literature supports a causal role of indoor allergens in disease development.

RECENT FINDINGS

High-risk birth cohorts continue to point to atopy as the main risk factor for developing asthma. Exposure to perennial allergens has also been linked to the development of asthma, though with less consistency. Intervention at the level of allergen exposure and allergic immune response is promising.

SUMMARY

The current model of atopic asthma, the predominant phenotype, incorporates genetic and environmental factors in the development of disease. Although genetic factors are less malleable, the environmental component lends itself to analysis and modification.For many, the development of asthma starts with allergen exposure leading to atopic sensitization and subsequent disease. Several studies support the progression from exposure to sensitization with the potential of extremely high levels of exposure leading to tolerance. Likewise, the progression from atopy to asthma is well documented,especially in genetically predisposed children. Recent intervention trials confirm these findings and begin to show promise for the prevention of asthma by interrupting the allergen exposure==>allergen sensitization==>atopic asthma pathway.

[Status and indications for SLIT in comparison to SCIT]

Appropriate specific immunotherapy depends on the correct diagnosis, identification of the clinically relevant allergens and consideration of risks. Standardized high-quality allergen extracts preferably of known major allergen content and with clear-cut proven efficacy in randomized controlled studies should be used for both SCIT and SLIT. The various SCIT and SLIT extracts differ considerably, so an allergen and product specific evaluation is recommended for the respective choice and indication. The German allergy society's comparison of SLIT to SCIT is much less favorable than that of the European society. In the absence of high-quality direct comparisons between the two therapies, a high-quality SCIT should be preferred to SLIT because long-term and preventive effects (development of asthma and new sensitizations) have been demonstrated more satisfactorily for SCIT. If SCIT is out of the question (refusal of injections, systemic side effects of SCIT) a high-quality SLIT may be indicated in adults with rhinoconjunctivitis.

Sublingual-oral administration of standardized allergenic extracts: phase 1 safety and dosing results

BACKGROUND

European studies provide a preponderance of evidence for sublingual allergen immunotherapy (SLIT) safety and efficacy, but they use allergen products that differ from those expected to be approved in the United States.

OBJECTIVE

To determine the safety and tolerability of 4 US-licensed standardized SLIT allergenic extracts.

METHODS

Adults 18 to 50 years old with allergic rhinitis with or without asthma due to timothy grass pollen, short ragweed pollen, house dust mite, or cat hair allergy completed a single-session dose escalation followed by an 8-week, open-label daily course of SLIT. Participants documented the presence and severity of adverse effects and adherence using a daily electronic diary.

RESULTS

Ninety-one participants initiated treatment, and 77 completed the phase 1 testing. Maximum tolerable doses ranged from 50 to 2,090 BAU for cat hair and dust mite extract, 31 to 91 Amb a 1 Units for short ragweed pollen extract, and 50 to 21,090 BAU for timothy grass pollen extract. During the 8-week treatment course, 98.9% of participants reported at least 1 mild, 70.4% at least 1 moderate, and 13.6% at least 1 severe adverse effect. Most adverse effects (94.6%) were rated as mild, 5.2% as moderate, and 0.1% as severe; nasal and oral-mucosal adverse effects were most commonly reported. No life-threatening adverse reactions occurred in more than 4,500 administered doses.

CONCLUSIONS

Daily sublingual-oral dosing of standardized allergenic extracts at maximum tolerable doses was generally well tolerated. These results are a first step toward establishing the safety of US-licensed SLIT extracts when appropriately self-administered and monitored.