Sublingual immunotherapy in asthma and rhinoconjunctivitis; systematic review of paediatric literature

A meta-analysis investigating the efficacy and safety of allergen-specific immunotherapy in the management of respiratory allergies

BACKGROUND

This meta-analysis aimed to evaluate the effectiveness and adverse effects of specific immunotherapy (SIT) in the management of respiratory allergens, including allergic asthma, rhinitis, and related disorders, based on a review of current literature up to November 8, 2022.

METHODS

We conducted a search of databases, including PubMed, Embase, Cochrane, and Web of Science, to identify relevant randomized controlled trials (RCTs) assessing respiratory allergy-specific immunotherapy. We employed the Consolidated Standards of Reporting Trials (CONSORT) Statement to select RCTs that adhered to rigorous reporting standards. Specifically, we focused on double-blind placebo-controlled (DBPC) trials and open studies involving both adults and children, considering factors such as dosage, inclusion criteria, allergens, and primary outcome measurements.

RESULTS

A total of 25 meta-analyses were included in this study. Among them, 14 evaluated sublingual-specific allergen immunotherapy (SLIT), 4 assessed subcutaneous allergen immunotherapy (SCIT), 4 explored both sublingual and subcutaneous immunotherapy, and 3 investigated intralymphatic immunotherapy. The outcomes of these meta-analyses indicated a reduction in medication scores in 20 cases and a decrease in symptom scores in 23 cases. Additionally, six studies reported on changes in IgE levels, seven studies focused on IgG4, four studies examined FEV1 (forced expiratory volume in 1 s), and eight studies reported on symptom and medication scores. Furthermore, 11 studies reported on differences in adverse reactions.

CONCLUSION

The results of our meta-analysis suggest that specific immunotherapy, while associated with some adverse effects, effectively reduces the symptoms of asthma and rhinitis. Therefore, we recommend its use in the treatment of respiratory allergies.

Reliability of the Evidence Addressing Treatment of Corneal Diseases: A Summary of Systematic Reviews

Importance

Patient care should be informed by clinical practice guidelines, which in turn should be informed by evidence from reliable systematic reviews. The American Academy of Ophthalmology is updating its Preferred Practice Patterns (PPPs) for the management of the following 6 corneal diseases: bacterial keratitis, blepharitis, conjunctivitis, corneal ectasia, corneal edema and opacification, and dry eye syndrome.

Objective

To summarize the reliability of the existing systematic reviews addressing interventions for corneal diseases.

Data Source

The Cochrane Eyes and Vision US Satellite database.

Study Selection

In this study of published systematic reviews from 1997 to 2017 (median, 2014), the Cochrane Eyes and Vision US Satellite database was searched for systematic reviews evaluating interventions for the management of any corneal disease, combining eyes and vision keywords and controlled vocabulary terms with a validated search filter.

Data Extraction and Synthesis

The study classified systematic reviews as reliable when each of the following 5 criteria were met: the systematic review specified eligibility criteria for inclusion of studies, conducted a comprehensive literature search for studies, assessed risk of bias of the individual included studies, used appropriate methods for quantitative syntheses (meta-analysis) (only assessed if meta-analysis was performed), and had conclusions that were supported by the results of the systematic review. They were classified as unreliable if at least 1 criterion was not met.

Main Outcomes and Measures

The proportion of systematic reviews that were reliable and the reasons for unreliability.

Results

This study identified 98 systematic reviews that addressed interventions for 15 corneal diseases. Thirty-three of 98 systematic reviews (34%) were classified as unreliable. The most frequent reasons for unreliability were that the systematic review did not conduct a comprehensive literature search for studies (22 of 33 [67%]), did not assess risk of bias of the individual included studies (13 of 33 [39%]), and did not use appropriate methods for quantitative syntheses (meta-analysis) (12 of 17 systematic reviews that conducted a quantitative synthesis [71%]). Sixty-five of 98 systematic reviews (66%) were classified as reliable. Forty-two of the 65 reliable systematic reviews (65%) addressed corneal diseases relevant to the 2018 American Academy of Ophthalmology PPPs; 33 of these 42 systematic reviews (79%) are cited in the 2018 PPPs.

Conclusions and Relevance

One in 3 systematic reviews addressing interventions for corneal diseases are unreliable and thus were not used to inform PPP recommendations. Careful adherence by systematic reviewers and journal editors to well-established best practices regarding systematic review conduct and reporting might help make future systematic reviews in eyes and vision more reliable.

Applicability of evidence from previous systematic reviews on immunotherapy in current practice of childhood asthma treatment: a GRADE (Grading of Recommendations Assessment, Development and Evaluation) systematic review

OBJECTIVE

Because most children with asthma now use inhaled corticosteroids (ICS), the added benefit of immunotherapy in asthmatic children needs to be examined. We re-assessed the effectiveness of subcutaneous (SCIT) and sublingual immunotherapy (SLIT) in childhood asthma treatment focusing on studies with patient-relevant outcome measures and children using ICS.

METHODS

We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to systematically search and appraise the evidence using predefined critical patient-relevant outcomes (asthma symptoms, asthma control and exacerbations). We searched to retrieve systematic reviews and randomised controlled trials on immunotherapy for asthma in children (1960-2017). We assessed the quality of the body of evidence with GRADE criteria.

RESULTS

The quality of the evidence for SCIT was very low due to a large risk of bias and indirectness (dated studies in children not using ICS). No effect of SCIT was found for asthma symptoms; no studies reported on asthma control. For asthma exacerbations, studies favoured SCIT. We have little confidence in this effect estimate, due to the very low quality of evidence. For SLIT, quality of the evidence was very low due to a large risk of bias, indirectness and imprecision. The outcome 'asthma symptoms' could not be calculated due to lack of standardisation and large clinical heterogeneity. Other predefined outcomes were not reported.

CONCLUSION

The beneficial effects of immunotherapy in childhood asthma found in earlier reviews are no longer considered applicable, because of indirectness (studies performed in children not being treated according to current asthma guidelines with ICS). There was absence of evidence to properly determine the effectiveness or lack thereof of immunotherapy in asthma treatment in children with ICS.

Allergen immunotherapy for allergic rhinoconjunctivitis: a systematic overview of systematic reviews

Background

The European Academy of Allergy and Clinical Immunology (EAACI) is developing Guidelines on Allergen Immunotherapy (AIT) for Allergic Rhinoconjunctivitis (ARC). To inform the development of recommendations, we sought to critically assess the systematic review evidence on the effectiveness, safety and cost-effectiveness of AIT for ARC.

Methods

We undertook a systematic overview, which involved searching nine international biomedical databases from inception to October 31, 2015. Studies were independently screened by two reviewers against pre-defined eligibility criteria and critically appraised using the Critical Appraisal Skills Programme (CASP) Systematic Review Checklist for systematic reviews. Data were descriptively synthesized.

Results

Our searches yielded a total of 5932 potentially eligible studies, from which 17 systematic reviews met our inclusion criteria. Eight of these were judged to be of high, five moderate and three low quality. These reviews suggested that, in carefully selected patients, subcutaneous (SCIT) and sublingual (SLIT) immunotherapy resulted in significant reductions in symptom scores and medication requirements. Serious adverse outcomes were rare for both SCIT and SLIT. Two systematic reviews reported some evidence of potential cost savings associated with use of SCIT and SLIT.

Conclusions

We found moderate-to-strong evidence that SCIT and SLIT can, in appropriately selected patients, reduce symptoms and medication requirements in patients with ARC with reassuring safety data. This evidence does however need to be interpreted with caution, particularly given the heterogeneity in the populations, allergens and protocols studied. There is a lack of data on the relative effectiveness, cost-effectiveness and safety of SCIT and SLIT. We are now systematically reviewing all the primary studies, including recent evidence that has not been incorporated into the published systematic reviews.

Electronic supplementary material

The online version of this article (doi:10.1186/s13601-017-0159-6) contains supplementary material, which is available to authorized users.

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.

Clinical considerations in the use of sublingual immunotherapy for allergic rhinitis

BACKGROUND

Allergen immunotherapy (AIT) has been in practice for more than 100 years. However, research in novel routes and delivery methods of immunotherapy to treat allergic rhinitis (AR) and conjunctivitis has only recently occurred in the United States, where the predominant form of AIT provided is largely via a subcutaneous immunotherapy (SCIT) route. AIT may prevent new sensitizations, improve symptoms, decrease medication usage, and prevent allergic asthma. Although AIT is the only potentially curative treatment for AR, access and adherence continue to be problematic. Only a fraction of eligible patients actually undergo treatment, and attrition rates are high. An obvious limitation of SCIT includes the requirement of regular injections to be provided in the physician's office due to the potential for anaphylaxis. Sublingual immunotherapy (SLIT) for home administration has been investigated as a potential alternative to address this limitation of SCIT.

METHODS

A literature review was performed including the current findings from randomized clinical trials and meta-analyses with a discussion of the most recent evidence for the efficacy, safety, and dosing of allergen SLIT.

RESULTS

The current data suggest that SLIT is effective for treatment of seasonal allergies, can potentially prevent asthma, and has a favorable safety profile. Head-to-head studies, however, are few, and comparative effectiveness still remains to be answered. Optimal treatment algorithms for SLIT have not yet been established, with wide variation in dosage selection and schedules. Similarly to SCIT, only a few allergens such as ragweed and grass pollen have been found to be effective in large clinical trials.

CONCLUSION

Recent data indicate that SLIT is an effective treatment modality for seasonal AR, improve quality of life, and can potentially prevent asthma but head-to head studies comparing SLIT to SCIT are needed.

Guiding principles of sublingual immunotherapy for allergic rhinitis in Japanese patients

OBJECTIVE

Sublingual immunotherapy (SLIT) appears to offer practical advantages for the treatment of allergic rhinitis (AR). Based on a review of the scientific literature, we present recommendations as guiding principles to administer SLIT safely.

METHODS

Clinical questions concerning SLIT were prepared. Literature published between January 2003 and December 2012 was searched from PubMed, the Cochrane Library, and Japana Centra Revuo Medicina. Qualified studies were analyzed and the results were evaluated, consolidated, and codified. We answered 17 clinical questions and, based on this, presented evidence-based recommendations.

RESULTS

Sublingual immunotherapy improved symptoms (e.g., quality of life [QOL]) and reduced medication scores in seasonal AR and perennial AR. Most SLIT-induced adverse effects were local oral reactions, although systemic adverse effects such as gastrointestinal symptoms, urticaria, and asthma are occasionally reported. There have been no reports of lethal anaphylactic reactions by SLIT. When SLIT is continued for 3-4 years, its effect persists long after discontinuation.

CONCLUSION

A correct diagnosis of AR and sufficient informed consent from patients are required before initiating SLIT. Sublingual immunotherapy should be continued for 3 years or longer. The initial administration of SLIT during the uptitration of an allergen vaccine and the general condition of patients are critical for the safe performance of SLIT.

Efficacy and safety of sublingual immunotherapy in children

Allergen immunotherapy (AIT) is currently the only available disease-modifying and aetiological treatment of IgE-mediated diseases. Sublingual allergen immunotherapy (SLIT) constitutes the preferred route of administration of AIT for respiratory allergies in Europe. Recently it has also been approved in the US. Further applications are currently under evaluation, such as IgE-mediated food allergy and IgE-mediated atopic dermatitis. The SLIT safety profile is overall favourable, although local adverse events, usually mild, are described. Most of the meta-analyses confirmed the efficacy of SLIT in reducing symptoms and medication intake in children with allergic diseases. AIT, as an immune-modulating treatment, can modify the natural history of the allergic diseases: reduction of the risk of development of asthma and bronchial hyperreactivity in patients with allergic rhinitis, and reduction of the onset of new sensitizations. A great interest is now devoted to the preventive effects of AIT and, consequently, to the optimal time of initiation.

House Dust Mite Respiratory Allergy: An Overview of Current Therapeutic Strategies

Although house dust mite (HDM) allergy is a major cause of respiratory allergic disease, specific diagnosis and effective treatment both present unresolved challenges. Guidelines for the treatment of allergic rhinitis and asthma are well supported in the literature, but specific evidence on the efficacy of pharmacotherapy treatment for known HDM-allergic patients is weaker. The standard diagnostic techniques--skin prick test and specific IgE testing--can be confounded by cross-reactivity. However, component-resolved diagnosis using purified and recombinant allergens can improve the accuracy of specific IgE testing, but availability is limited. Treatment options for HDM allergy are limited and include HDM avoidance, which is widely recommended as a strategy, although evidence for its efficacy is variable. Clinical efficacy of pharmacotherapy is well documented; however, symptom relief does not extend beyond the end of treatment. Finally, allergen immunotherapy has a poor but improving evidence base (notably on sublingual tablets) and its benefits last after treatment ends. This review identifies needs for deeper physician knowledge on the extent and impact of HDM allergy in respiratory disease, as well as further development and improved access to molecular allergy diagnosis. Furthermore, there is a need for the development of better-designed clinical trials to explore the utility of allergen-specific approaches, and uptake of data into guidance for physicians on more effective diagnosis and therapy of HDM respiratory allergy in practice.

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.

Sublingual immunotherapy in children with allergic rhinitis: quality of systematic reviews

Systematic reviews have gained popularity as a way to combine the increasing amount of research information. This study assessed the quality of systematic reviews and meta-analyses of sublingual immunotherapy (SLIT) for allergic rhinitis in children, published since 2000. Eligible reviews were identified by searching Medline/Pubmed, Embase, and the Cochrane Library, from 2000 through 2008. Methodological quality was assessed using the assessment of multiple systematic reviews instrument. Ten systematic reviews were included, one of which was published in the Cochrane Library. Eight reviews gave some details about the search strategy. None of the reviews included measures to avoid selection bias. In 60% of the reviews, the methodological quality of the included studies was (partly) assessed. Four reviews pooled the results of individual studies, neglecting clinical heterogeneity. Three of the 10 reviews provided information about sources of funding or grants from industry. Of the 10 reviews, the six reviews with the highest overall score scored 5-8 points, indicating moderate quality. Systematic reviews are useful to evaluate the efficacy of SLIT in children. Although more reviews have become available, the methodological quality could be improved. SLIT for children could be promising, but methodological flaws in the reviews and individual studies are too serious to draw definite conclusions.

New approaches to managing asthma: a US perspective

Despite remarkable advances in diagnosis and long-term management, asthma remains a serious public health concern. Newly updated expert guidelines emphasize the intra- and inter-individual variability of asthma and highlight the importance of periodic assessment of asthma control. These guidelines update recommendations for step-wise asthma treatment, address the burgeoning field of asthma diagnostics, and stress the importance of a patient and health care professional partnership, including written action plans and self monitoring. The field of asthma therapeutics is expanding rapidly, with promising new treatment options available or in development that may address some of the existing barriers to successful asthma management. These approaches simplify treatment, use combinations of agents in one delivery device that have complementary actions, or target specific pathways involved in asthma patho-physiology. Considerable activity is taking place in asthma pharmacogenetics. This review provides an overview of these new approaches to managing asthma, including their present status and future potential.

Current management of allergic rhinitis in children

Over the last 20 years, there has been significant progress in our understanding of the pathophysiology of allergic rhinitis, including the discovery of new inflammatory mediators, the link between asthma and allergic rhinitis ('one airway-one disease' concept) and the introduction of novel therapeutic modalities. These new insights have been documented in the Allergic Rhinitis and its Impact on Asthma guidelines and have led to the creation of evidence-based management algorithms. We now understand the importance of a common strategy for treating allergic inflammation of the upper and lower airway as a way of improving outcome, reducing hospital admissions, providing better quality of life and perhaps, altering the natural course of the 'allergic march'. A therapeutic ladder is suggested: Whereas for mild intermittent allergic rhinitis, allergen avoidance should be the first line of treatment with subsequent addition of a second generation topical or oral antihistamine, nasal saline or cromoglycate, in cases of moderate to severe allergic rhinitis, a nasal steroid is the treatment of choice. If a patient with moderate/severe persistent allergic rhinitis fails to improve after 4 wk of adequate treatment, patient compliance or the diagnosis must be re-assessed. In such cases, when the diagnosis is in doubt, a careful clinical examination including nasal endoscopy is mandatory to assess for other potential causes of nasal obstruction. In children who suffer from concomitant allergic rhinitis and asthma, a management algorithm that addresses concurrently asthma and allergic rhinitis is vital, both from a theoretical and from a practical point of view: Parents overwhelmingly prefer a single strategy for the treatment of their child's upper and lower airway symptoms; however, the overall quality of life in children with severe asthma can be significantly improved if rhinitis is adequately addressed.

Sublingual immunotherapy in children: facts and needs

Allergen specific immunotherapy (SIT) is the practice of administering gradually increasing doses of the specific causative allergen to reduce the clinical reactivity of allergic subjects, and is the only treatment targeting the causes of hypersensitivity and not only the symptoms, as done by drugs. The traditional, subcutaneous immunotherapy (SCIT) was burdened by the problem of systemic reactions which may be sometimes severe and - though very rarely - even fatal. This was the background to develop non injections routes for SIT and particularly sublingual immunotherapy (SLIT), that emerged as a real treatment option for respiratory allergy.

A number of studies was conducted to evaluate efficacy and safety of SLIT, the first meta-analysis - including 22 placebo-controlled trials - concluded for positive results in both issues, but the number of studies on children was too low to draw definite conclusions. Since then, many other studies became available and make possible to analyze SLIT in children in its well defined aspects as well as in sides still requiring more solid data.

The effect of caffeic acid phenethyl ester on the functions of human monocyte-derived dendritic cells

Background

Propolis, an ancient herbal medicine, has been reported the beneficial effect both in asthma patients and murine model of asthma, but the mechanism was not clearly understood. In this study, the effect of caffeic acid phenethyl ester (CAPE), the most extensively studied components in propolis, on the functions of human monocyte-derived dendritic cells (MoDCs) was investigated.

Results

CAPE significantly inhibited IL-12 p40, IL-12 p70, IL-10 protein expression in mature healthy human MoDCs stimulated by lipopolysaccharides (LPS) and IL-12 p40, IL-10, IP-10 stimulated by crude mite extract. CAPE significantly inhibited IL-10 and IP-10 but not IL-12 expression in allergic patients' MoDCs stimulated by crude mite extract. In contrast, the upregulation of costimulatory molecules in mature MoDCs was not suppressed by CAPE. Further, the antigen presenting ability of DCs was not inhibited by CAPE. CAPE inhibited IκBα phosphorylation and NF-κB activation but not mitogen-activated protein kinase (MAPK) family phosphorylation in human MoDCs.

Conclusion

These results indicated that CAPE inhibited cytokine and chemokine production by MoDCs which might be related to the NF-κB signaling pathway. This study provided a new insight into the mechanism of CAPE in immune response and the rationale for propolis in the treatment of asthma and other allergic disorders.

Sublingual immunotherapy in children: complete and updated review supporting evidence of effect

PURPOSE OF REVIEW

The interest in sublingual immunotherapy (SLIT) is still growing worldwide and especially for the pediatric age group, this modality is appealing. Lately, some negative systematic review articles have been published on SLIT in children. However, high quality articles published from 2007 onward had not been included.

RECENT FINDINGS

Explanations are sought for the negative outcomes in these reviews and shortcomings are discussed. New pediatric studies - not included in the previous reviews -designed taking into account the golden rules for SLIT (high daily dose, starting at least 4 months before pollen season) do show statistically significant improvement in symptom and medication scores for rhinitis and asthma in pollen allergy. New house dust mite studies still show inconsistent data.

SUMMARY

Evidence of effect is confirmed for SLIT in children with allergic rhinitis or asthma caused by pollen exposure. For house dust mite asthma, evidence is still nonconcordant. New techniques to improve SLIT efficacy are under investigation.

Specific immunotherapy for respiratory allergy: state of the art according to current meta-analyses

OBJECTIVE

To evaluate the efficacy of allergen specific immunotherapy in the treatment of allergic asthma and rhinitis as derived by the available meta-analyses.

DATA SOURCES

Electronic databases were searched up to April 30, 2008, for meta-analyses of randomized, placebo-controlled trials assessing specific immunotherapy in respiratory allergy. We looked for studies that evaluated effects on symptom scores and use of rescue medication.

STUDY SELECTION

If 2 or more reviews evaluated the same subject, we selected the study with the larger number of patients. We evaluated the quality of individual meta-analyses by following the recommendations of the Cochrane Collaboration and the QUOROM (Quality of Reporting of Meta-analyses) statement.

RESULTS

Seven of 13 meta-analyses met the inclusion criteria: 5 evaluating sublingual immunotherapy and 2 evaluating subcutaneous immunotherapy. All 7 meta-analyses reported a reduction in symptom and medication scores, although 1 sublingual immunotherapy meta-analysis did not find a significant size effect, probably because of the inclusion criteria. Heterogeneity was significant in all 7 included reviews, and standardized mean differences using the random-effects model were adopted.

CONCLUSIONS

According to evidence-based criteria, specific immunotherapy can be recommended for the treatment of respiratory allergy because of its efficacy in reducing asthma and rhinitis symptoms. Also, future methodological approaches that consider safety and costs should corroborate this positive evaluation.

Preventive effects of sublingual immunotherapy in childhood: an open randomized controlled study

BACKGROUND

Sublingual immunotherapy (SLIT) has been proved to be effective in allergic rhinitis and asthma, but there are few data on its preventive effects, especially in children.

OBJECTIVE

To evaluate the clinical and preventive effects of SLIT in children by assessing onset of persistent asthma and new sensitizations, clinical symptoms, and bronchial hyperreactivity.

METHODS

A total of 216 children with allergic rhinitis, with or without intermittent asthma, were evaluated and then randomized to receive drugs alone or drugs plus SLIT openly for 3 years. The clinical score was assessed yearly during allergen exposure. Pulmonary function testing, methacholine challenge, and skin prick testing were performed at the beginning and end of the study.

RESULTS

One hundred forty-four children received SLIT and 72 received drugs only. Dropouts were 9.7% in the SLIT group and 8.3% in the controls. New sensitizations appeared in 34.8% of controls and in 3.1% of SLIT patients (odds ratio, 16.85; 95% confidence interval, 5.73-49.13). Mild persistent asthma was less frequent in SLIT patients (odds ratio, 0.04; 95% confidence interval, 0.01-0.17). There was a significant decrease in clinical scores in the SLIT group vs the control group since the first year. The number of children with a positive methacholine challenge result decreased significantly after 3 years only in the SLIT group. Adherence was 80% or higher in 73.8% of patients. Only 1 patient reported systemic itching.

CONCLUSIONS

In everyday clinical practice, SLIT reduced the onset of new sensitizations and mild persistent asthma and decreased bronchial hyperreactivity in children with respiratory allergy.

Immunotherapy in children and adolescents with allergic rhinoconjunctivitis: a systematic review

Allergen-specific immunotherapy is one of the cornerstones of allergic rhinoconjunctivitis treatment. Since the development of non-invasive administration forms with better safety profiles, there is an increasing tendency to prescribe immunotherapy in youngsters. However, no overview is available on the efficacy of immunotherapy in all its different administration forms in youngsters. Therefore, we systematically reviewed randomized controlled trials (RCTs) to evaluate the effect of immunotherapy with inhalant allergens on symptoms and medication use in children and adolescents with allergic rhinoconjunctivitis. Medline, EMBASE, the Cochrane Controlled Clinical Trials Register and reference lists of recent reviews and published trials were searched. RCTs including youngsters aged 0-18 yr with allergic rhinoconjunctivitis and comparing immunotherapy with placebo, symptomatic treatment or a different administration form of immunotherapy were included. Primary outcome measures were rhinoconjunctivitis symptom and/or medication scores. Methodological quality was assessed using the validated Delphi list. A method of best evidence synthesis, a rating system with levels of evidence based on the overall quality and the outcome of the trials, was used to assess efficacy. Six subcutaneous (SCIT), four nasal (LNIT), seven oral (OIT) and 11 sublingual (SLIT) immunotherapy trials, comprising 1619 youngsters, were included. Only 39% of the trials were of high methodological quality. For the SCIT and OIT subgroups the level of evidence for efficacy was conflicting. Moderate evidence of effect was found for LNIT. Analysis of the SLIT subgroup showed no evidence of effect. The evidence for the perennial and seasonal allergen trials within the subgroups varied from moderate evidence of effect to no evidence of effect. In conclusion, there is at present insufficient evidence that immunotherapy in any administration form has a positive effect on symptoms and/or medication use in children and adolescents with allergic rhinoconjunctivitis.

Sublingual immunotherapy in children

Sublingual immunotherapy (SLIT) is a safe and patient-friendly variant of allergen immunotherapy. These characteristics may provide physicians with a therapy, perfectly suited to the treatment of allergic children. To give an overview of currently published studies on SLIT in children Pubmed was searched for randomised clinical trials (RCTs). In addition available systematic reviews and long-term observational studies were analysed. Until now, 13 RCTs on allergic rhinitis, 22 studies on asthma (including eight studies involving only children) and one study on atopic dermatis have been published. In addition, five systematic reviews on allergic rhinitis have been published and one is in press. One meta-analysis of adults and children with asthma has been reported. All studies report varying results. The effects and their magnitude differ between studies. Systematic reviews give inconsistent results. For allergic rhinitis three reviews appeared to be negative, two were positive and one analysis was inconsistent regarding children. In asthma a meta-analysis involving both adults and children concluded that SLIT is moderately effective. From observational studies effects of SLIT are suggested to persist after discontinuation. Randomised trials indicate that SLIT may prevent the onset of asthma and new sensitisations. As long as evidence for effectiveness is weak, SLIT cannot be firmly recommended in clinical practice. Nevertheless, the proven effectiveness of SLIT in adults supports the proof in principle of this therapy. In the near future immunotherapy trials in children may provide the required proof of effectiveness.

Oral tolerance attenuates changes in in vitro lung tissue mechanics and extracellular matrix remodeling induced by chronic allergic inflammation in guinea pigs

Recent studies emphasize the presence of alveolar tissue inflammation in asthma. Immunotherapy has been considered a possible therapeutic strategy for asthma, and its effect on lung tissue had not been previously investigated. Measurements of lung tissue resistance and elastance were obtained before and after both ovalbumin and acetylcholine challenges. Using morphometry, we assessed eosinophil and smooth muscle cell density, as well as collagen and elastic fiber content, in lung tissue from guinea pigs with chronic pulmonary allergic inflammation. Animals received seven inhalations of ovalbumin (1-5 mg/ml; OVA group) or saline (SAL group) during 4 wk. Oral tolerance (OT) was induced by offering ad libitum ovalbumin 2% in sterile drinking water starting with the 1st inhalation (OT1 group) or after the 4th (OT2 group). The ovalbumin-exposed animals presented an increase in baseline and in postchallenge resistance and elastance related to baseline, eosinophil density, and collagen and elastic fiber content in lung tissue compared with controls. Baseline and post-ovalbumin and acetylcholine elastance and resistance, eosinophil density, and collagen and elastic fiber content were attenuated in OT1 and OT2 groups compared with the OVA group. Our results show that inducing oral tolerance attenuates lung tissue mechanics, as well as eosinophilic inflammation and extracellular matrix remodeling induced by chronic inflammation.

Diagnosis and treatment of asthma in childhood: a PRACTALL consensus report

Asthma is the leading chronic disease among children in most industrialized countries. However, the evidence base on specific aspects of pediatric asthma, including therapeutic strategies, is limited and no recent international guidelines have focused exclusively on pediatric asthma. As a result, the European Academy of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma and Immunology nominated expert teams to find a consensus to serve as a guideline for clinical practice in Europe as well as in North America. This consensus report recommends strategies that include pharmacological treatment, allergen and trigger avoidance and asthma education. The report is part of the PRACTALL initiative, which is endorsed by both academies.

New perspectives in the treatment of allergic rhinitis and asthma in children

PURPOSE OF REVIEW

Allergic rhinitis and asthma are some of the most prevalent chronic diseases in children. Meticulous evaluations of the therapeutic options and interventions are needed to control this burden. The central pathogenic mechanism is an immediate hypersensitivity reaction, followed by interventions in the allergic cascade. Once inflammation is established, potent anti-inflammatory agents or mediator antagonists could help control the phenomenon and reduce the characteristic symptoms related to severity.

RECENT FINDINGS

Monoclonal antibody against IgE has demonstrated its efficacy in reducing the symptoms of asthma and rhinitis. In difficult-to-treat asthma patients it allows a reduction in the dose of inhaled steroids, the number of exacerbations, emergency visits and hospitalizations. Its broad implementation is limited by its high cost because adverse events are not a concern. Specific sublingual immunotherapy gave promising results in clinical trials, while modifying immunoglobulins and cytokine profiles, also inducing T-cell tolerance. Safety issues of subcutaneous immunotherapy have been surpassed by the sublingual route, with equivalent efficacy. The new inhaled steroid ciclesonide is effective in established inflammation, is activated only in the respiratory system, and has negligible systemic effects.

SUMMARY

Robust evidence on the efficacy and safety of several novel therapies in rhinitis and asthma is available.

Clinical efficacy and safety of sublingual immunotherapy with tree pollen extract in children

BACKGROUND

Subcutaneous immunotherapy has been the principal approach of immunotherapy in the treatment of allergic diseases. Several clinical studies with birch, alder or hazel pollen extract conducted as subcutaneous immunotherapy have been published suggesting a well-tolerated and clinically effective treatment. Only a few clinical studies of sublingual immunotherapy (SLIT) with these allergens have been published. This study investigated the clinical efficacy, safety and dose-response relationship of SLIT in children suffering from rhinoconjunctivitis with/without asthma.

METHODS

Eighty-eight children (5-15 years) with a history of tree pollen-induced allergic rhinoconjunctivitis with/without seasonal asthma for >or=2 years were included. Allergy to tree pollen was confirmed by positive skin-prick test, positive specific IgE and positive conjunctival provocation test. The extract used was a glycerinated mixture of Betula verrucosa, Corylus avellana and Alnus glutinosa 100,000 SQ-U/ml. Children were randomized into three groups receiving SLIT 5 days a week for up to 18 months; dose group 1: accumulated weekly dose of 24,000 SQ-U; dose group 2: accumulated weekly dose of 200,000 SQ-U; and placebo.

RESULTS

In the birch pollen season, dose group 2 showed a significant reduction of symptom (P = 0.01) and medication scores (P = 0.04) compared with placebo. Dose group 1 showed a significant reduction of symptom scores (P = 0.03). There were no statistical differences between dose groups 1 and 2. All children tolerated the treatment well.

CONCLUSION

SLIT with tree pollen extract provided dose-dependent benefits in tree pollen-allergic children in terms of significantly reduced symptoms and medication use. The treatment was well tolerated.

Efficacy of sublingual immunotherapy in asthma: systematic review of randomized-clinical trials using the Cochrane Collaboration method

BACKGROUND

Sublingual immunotherapy (SLIT) is effective and safe in the treatment of allergic rhinitis. However, there is no meta-analysis in asthma treatment.

METHODS

The clinical efficacy of SLIT for asthma was evaluated through a systematic review with meta-analysis. MEDLINE (1966-2005), EMBASE (1974-2005), LILACS (1982-2005), and the Cochrane Library were searched for related literature in any language. Randomized-controlled clinical trials (RCT) on SLIT in asthma treatment for adults and children were selected. From 119 citations, 25 studies with 1706 patients were included in this meta-analysis. For each report, quality scores were assigned and data were extracted in relation to the outcomes analyzed: asthmatic symptoms, use of asthma medications, lung function, and bronchial provocation.

RESULTS

According to the Jadad quality method, 64% of the studies were assigned scores of 4 or 5. Immunotherapy was seen to significantly reduce asthma severity when parameter compositions were all analyzed by categorical outcomes. There was a nonsignificant reduction in asthma symptoms when analyzed using standardized mean differences. No severe reactions were observed.

CONCLUSIONS

This meta-analysis found that SLIT is beneficial for asthma treatment albeit the magnitude of the effect is not very large. Moreover, it is a safe alternative to the subcutaneous route. More RCT with standardization of symptom scores and medications are needed in order to contribute further to this subject.

Sublingual immunotherapy of allergic diseases

The only disease-modifying treatment that is available for allergic patients is allergen-specific immunotherapy. Two competing application forms are used: subcutaneous immunotherapy, which has been used for > 90 years, and a relatively new immunotherapy where the allergen is applied sublingually. Numerous studies have shown efficacy for subcutaneous immunotherapy and have identified possible mechanisms that are responsible for the observed reduction in allergic responses. In contrast, the efficacy of sublingual immunotherapy has not been documented to the same degree and the responsible immunological mechanisms have not yet been clearly defined. This review focuses on the published clinical and experimental data on sublingual immunotherapy and points at possible mechanisms of how sublingual immunotherapy may differ from subcutaneous immunotherapy in its mode of action, and also discusses the potential advantages and pit falls of both therapies.

The development of respiratory inflammation in children

With the rising world burden of asthma, it is crucial to define the early events that lead to chronic inflammation and airway remodelling. Chronic airway inflammation appears to be the culmination of both local epithelial dysfunction and a more generalised immune dysregulation that results in allergic predisposition. A number of antenatal and early postnatal events may contribute to this. However, although a systemic propensity for allergic responses (typically food allergy) frequently pre-exists in children who go on to develop asthma, there is still uncertainty over whether epithelial changes occur as a primary event or whether these are consequent to this evolving systemic propensity for type 2 T-helper cell allergic responses. Many children with asthma already show many of the features of chronic airway inflammation, with epithelial desquamation, inflammatory cell infiltrates, subepithelial basement membrane thickening and fibrosis, goblet cell hyperplasia and smooth muscle hypertrophy. These changes can be evident before asthma is diagnosed, and there is also evidence that airway inflammation and early remodelling can progress in a subclinical state. New studies suggest that early airway damage is irreversible and that subsequent lung function is 'set' in the first years of life. These observations highlight the need to identify affected or at-risk children early and to develop interventions that can abort or prevent ongoing airway inflammation and remodelling.

Absence of systemic immunologic changes during dose build-up phase and early maintenance period in effective specific sublingual immunotherapy in children

BACKGROUND

Sublingual immunotherapy (SLIT) has been reported to be a safe treatment for inhalant allergies in children. Yet the immunologic mechanisms resulting in clinical improvement are poorly understood.

OBJECTIVE

To identify early systemic immunologic changes during the first 8 weeks of clinically effective SLIT to grass pollen, tree pollen or house dust mite in paediatric patients with allergic rhinoconjunctivitis and/or asthma.

METHODS

Peripheral blood mononuclear cells and plasma samples of 13 children with reduced symptoms after 1 year of SLIT were obtained before therapy and at 2 and 8 weeks after the initiation of SLIT. Allergen-specific lymphocyte proliferation assays were performed, and allergen-induced cytokine production (IL-2, IL-4, IL-10, IFN-gamma, and TGF-beta(1)) was measured by ELISA and flow cytometry. Allergen-specific IgE, IgG1, IgG4, and IgA levels in plasma samples were determined in ELISA.

RESULTS

During the first 8 weeks of successful SLIT, allergen-specific lymphoproliferation (n=13) as well as levels of allergen-specific intracellular (n=8) and secreted cytokines (n=9) did not change significantly. In addition, no alterations in levels of allergen-specific Igs (n=7) were observed.

CONCLUSION

We could not find any early systemic immunologic changes during the first 8 weeks of clinically effective SLIT to inhalant allergens in paediatric patients with allergic rhinoconjunctivitis and/or asthma.

Safety and tolerability of ultra-rush induction, less than one hour, of sublingual immunotherapy in children

BACKGROUND

The safety and tolerability of sublingual immunotherapy (SLIT) has been documented in allergic patients both in the build-up phase as well as during maintenance, but only two studies have evaluated the occurrence of adverse reactions with an ultra-rush regimen of SLIT induction in a mixed paediatric/adult population. Moreover one of these two studies used a chemically modified extract (allergoid). The aim of the present study was to evaluate the occurrence of immediate or late adverse reactions in allergic children after a very fast (40 min) ultra-rush SLIT induction with two different allergen extract solutions.

METHODS

We studied 100 children (64 boys, mean age of 9.6 years, range 3.5-16.8), with a history of intermittent/persistent rhinitis and/or intermittent/mild persistent asthma due to inhalant allergens. The ultra-rush build-up phase involved the administration, every 10 min, of increasing doses of the highest-concentration vial of SLIT of two different manufacturers (Anallergo and Stallergènes).

RESULTS

All patients completed the treatment, side-effects have been recorded in 19% of the cases: 10% within 1 h after the build-up phase, 7% within 48 h and 2% mixed. A major difference (p = 0.0001) was recorded between Anallergo (6 patients, 8.7%) and Staloral (13 patients, 41.9%), but all the reactions were mild: principally oral symptoms, in 1 case rhinorrhoea and cough, and delayed abdominal pain and diarrhoea in another patient.

CONCLUSIONS

No severe adverse reactions were observed with this ultra-rush SLIT induction also in the paediatric age; statistical differences have been documented between the two different extracts.

Viewpoint: are doctors responsible for the increase in allergic diseases?

There is no exact explanation for the increase in allergic diseases that occurred since the last two decades. An increased allergen exposure and/or a decreased bacterial load cannot explain the phenomenon completely. Other causal factors that rose at the beginning of the 1980s must be taken into consideration. Important changes at that time in our management of children were the worldwide switch from aspirin to paracetamol, the introduction of broad-spectrum antibiotics such as cephalosporins and the advice to avoid dust and pets in newborns from allergic families. General application of these new approaches, in itself or in combination, might be responsible, at least in part, for the increase of allergic diseases in children.

Sublingual immunotherapy for allergic rhinoconjunctivitis--the seeming and the real

BACKGROUND

Subcutaneous specific immunotherapy (SIT) has been shown to be a causal treatment with long-term efficacy for allergic rhinoconjunctivitis and asthma, and a preventive measure against the development of asthma and new sensitizations. As it is associated with several inconveniences and serious side effects, sublingual immunotherapy (SLIT) has been developed to evade these problems.

METHODS

The present review of previously published studies on allergic rhinoconjunctivitis aimed to determine the efficacy of SLIT in comparison with subcutaneous treatment and to summarize long-term results of immunotherapy and its effects on the prevention and treatment of asthma and the prevention of new sensitizations.

RESULTS

The effect of SLIT on allergic rhinoconjunctivitis is low to moderate, depends on the allergen used and is more pronounced in adults than in children, in whom a consistent effect has not been demonstrated. Direct comparison with SIT shows conflicting and inconsistent results. Detailed studies on the prevention of asthma and new sensitizations are not available. Consistent effects of asthma treatment on both symptom and medication scores and lung function have not been reported. A quantitative evaluation is not possible due to indistinct inclusion criteria and different outcome criteria. In summary, currently SLIT plays no significant role in the treatment of asthma, apart from children monosensitized to house dust mites in whom it may have low-moderate effects. Only one study deals with the long-term efficacy of SLIT, which demonstrated a persistent positive effect on asthma, whereas data on rhinoconjunctivitis are completely lacking.

CONCLUSIONS

Primary and secondary targets of specific immunotherapy have not been answered satisfactorily for the sublingual route. To date, SLIT cannot be recommended as an adequate alternative to the subcutaneous form. Questions regarding the cumulative dose, duration of therapy and immunological mechanisms have also not been answered. The indication should thus be limited to adult patients with pollen-induced rhinoconjunctivitis being unable to perform SIT, e.g. due to significant side effects.