Efficacy of sublingual specific immunotherapy in patients with respiratory allergy to Alternaria alternata: a randomised, assessor-blinded, patient-reported outcome, controlled 3-year trial

Exploring Side Effects of Sublingual Immunotherapy: A Systemic Review and Meta-Analysis

Objective: Sublingual immunotherapy (SLIT) has emerged as a potentially safe and convenient option for allergen immunotherapy for patients with inhalant allergy. Larger studies on the overall side effects and severe reactions anaphylaxis are still lacking. Study Design: Systematic review and meta-analysis. Setting: Author's review was completed in the University of Texas Medical Branch. Methods: A systematic review and meta-analysis of prospective clinical trials focusing on SLIT safety published from January 1, 2001, to December 31, 2021, was conducted. Results: Twenty-six studies were included with analysis of 7827 patients, representing over 2.7 million SLIT doses. All studies focused on single-antigen immunotherapy. The mean duration of treatment was 11.54 months. Local side effects were present in 40.83% of patients [95% confidence interval (CI) 24.78-57.96]. Systemic side effects were encountered in 1.09% of SLIT patients (95% CI 0.57-1.78). Anaphylaxis was reported in 0.13% of patients (95% CI 0.06-0.22). Discontinuation rates due to side effects were low, at 4.32% of patients (95% CI 3.28-5.49). Conclusion: This meta-analysis shows that single-antigen SLIT is well-tolerated, with overall low rates of systemic side effects including anaphylaxis. Although there is a high rate of minor local side effect, the treatment attrition during the first year is low. With growing allergy burden worldwide, SLIT is a convenient and economically feasible option for immunotherapy. Further work is needed to evaluate long-term safety and efficacy of single as well as multi-antigen SLIT, including quality of life assessments.

Allergy immunotherapy for allergic fungal respiratory diseases

Background: Allergy immunotherapy (AIT) with fungal extracts is not as straight forward as that with other inhalants. The complexities relate to the number of airborne fungal spores, the limited data on the exposure to the spores of individual species of fungi and their clinical importance, the poor quality of the fungal allergen extracts that are available for the diagnosis and treatment, and the lack of controlled studies establishing dosing and efficacy of AIT with fungal extracts except for Alternaria. Objective: The objective was to review what is known with regard to the role of fungi in causing allergic respiratory diseases as well as the evidence that exists for the role of AIT as a treatment for these conditions. Methods: A search was conducted of PubMed, textbooks, known articles on immunotherapy with fungal extracts, and references derived from these primary sources. Results: Nine immunotherapy studies that used Alternaria or its major allergen Alt a 1 and two studies that used Cladosporium herbarum were identified. When a good quality extract was administered in adequate doses, immunotherapy with Alternaria was as effective as that with other inhalant allergens. There was a suggestion of efficacy with a specially prepared Cladosporium extract, but systemic reactions were common and limited the tolerated dose. The use of immunotherapy as an adjunct treatment for allergic fungal sinusitis is briefly reviewed, but controlled trials are lacking. Conclusion: Fungal immunotherapy should largely be limited to Alternaria alternata and perhaps C. herbarum. Under conditions of demonstrated exposure to a particular species of fungus and with symptoms that correlate with that exposure as well as availability of an apparently potent extract of that fungus to which the patient is sensitive that fungus may be considered for immunotherapy. Fungal (mold) mixes should not be used for diagnosis or therapy.

Changes of allergic inflammation and immunological parameters after Alt a 1 and A. alternata immunotherapy in mice

Background

The efficacy of allergen-specific subcutaneousimmunotherapy (SCIT) with Alt a 1 of the fungus A. alternata is still unknown. Yet, few studies compare the therapeutic effects and immunological mechanisms of Alt a 1 and A. alternata extracts. We aim to explore and compare the changes in allergic inflammation and immunological mechanisms of Alt a 1 and A. alternata in mice.

Methods

Female BALB/c mice administrated recombinant Alt a 1 (rAlt a 1), native Alt a 1 (nAlt a 1), and A. alternata. Lung histology, airway hyper-reactivity (AHR), bronchoalveolar lavage fluid (BALF) cytokine levels, serum immunoglobulin responses, the expression of Bcl-6, the percentages of T follicular helper cells (Tfh), cytokine-related Tfh subtypes, regulatory B cells (Breg), and IL-10+ Breg cells were detected.

Results

High-purity nAlt 1 protein was obtained. SCIT with Alt a 1 and Alternaria decreased airway and lung inflammation, including improvement of lung pathology, lower levels of AHR, reduction of total cell numbers, and IL-4 and IL-13 levels in BALF. Furthermore, Alt a 1-SCIT effectively suppressed the IgE responses, elevated IgG titers, and was superior in decreasing the expression of Bcl-6. Additionally, Alternaria-SCIT significantly decreased the expression of Tfh cells, L-4+ Tfh, and IL-5+ Tfh cells in the spleen, whereas Alt a 1 showed superior therapeutic effects in the lymph node. IL-13+ Tfh cells in these two treatment groups not being significant. IL-17A+ Tfh cells were alleviated most effectively after A. alternata-SCIT in both the spleen and lymph node. Intriguingly, IL-10+ Breg cells decreased remarkably in response to SCIT with rAlt a 1.

Conclusions

Treatments with Alt a 1 and A. alternata extracts had beneficial effects on allergic inflammation. Alt a 1-SCIT resulted in prominent improvement in the immunoglobulin responses, Bcl-6, and IL-10+ Breg cells. Alternaria-SCIT was more likely to suppress the expression of Tfh and cytokine-related Tfh subtypes.

Comparison of weight per volume and protein nitrogen units in non-standardized allergen extracts: implications for prescribing subcutaneous immunotherapy

Background

Allergen extracts used in subcutaneous immunotherapy can be standardized or non-standardized. Standardized extracts are available in specific biological potencies, presumably making their biological activity more consistent. The majority of allergen extracts are non-standardized and may have less consistent potencies. Non-standardized extracts are labeled as weight per volume or protein nitrogen units (PNUs). Neither method provides direct information regarding the extract’s biologic potency. The purpose of this study was to compare weight per volume versus PNU concentrations for 4 non-standardized allergen extracts prepared by two allergen manufacturers. The potencies were compared to current North American practice recommendations.

Methods

The weight per volume and PNU values were provided for 4 non-standardized extracts—birch, short ragweed, dog hair and Alternaria—from HollisterStier and Stallergenes Greer. Weight per volume and PNU concentrations were compared for each of these extracts from both manufacturers. From the raw data, we calculated the corresponding PNU values for a weight per volume of 1:100 and 1:200 for each extract. Similarly, we calculated the corresponding weight per volume including a range of PNU values, for 1000, 2000, 3000, 4000 and 5000 PNU/ml.

Results

Birch extract has low PNU concentration, below 5000, for a weight per volume of 1:200 for both HollisterStier and Stallergenes Greer. In contrast, for both HollisterStier and Stallergenes Greer ragweed extract, a weight per volume of 1:200 corresponds to a PNU concentration greater than 5000. Dog extract for a weight per volume of 1:200, and even for 1:100, corresponds to very low PNUs for both companies. For Alternaria, corresponding PNU concentrations for HollisterStier is low at only 500 while over 5000 for Stallergenes Greer.

Conclusions

Our results show variability when comparing weight per volume and PNU concentrations for both Hollister-Stier and Stallergenes Greer products. We suggest selecting a PNU dose that corresponds to a weight per volume of 1:200 as this may improve patient safety. Our recommendations for starting PNU dose for the four non-standardized extracts are 1500 for birch, 5000 for ragweed, 25 for dog, and 500 for Alternaria when using HollisterStier products; 2300 for birch, 5000 for ragweed, 1200 for dog, and 5000 for Alternaria when using Stallergenes Greer products. If the starting PNU concentration is considerably below 5000 for a weight per volume of 1:200 slow up-titration is advised. Conversely, for PNU concentrations above 5000 for weight per volume of 1:200 we suggest a maintenance dose of 5000 PNU.

Sublingual immunotherapy for asthma

BACKGROUND

Asthma is a common long-term respiratory disease affecting approximately 300 million people worldwide. Approximately half of people with asthma have an important allergic component to their disease, which may provide an opportunity for targeted treatment. Sublingual immunotherapy (SLIT) aims to reduce asthma symptoms by delivering increasing doses of an allergen (e.g. house dust mite, pollen extract) under the tongue to induce immune tolerance. Fifty-two studies were identified and synthesised in the original Cochrane Review in 2015, but questions remained about the safety and efficacy of sublingual immunotherapy for people with asthma.

OBJECTIVES

To assess the efficacy and safety of sublingual immunotherapy compared with placebo or standard care for adults and children with asthma.

SEARCH METHODS

The original searches for trials from the Cochrane Airways Group Specialised Register (CAGR), ClinicalTrials.gov, WHO ICTRP, and reference lists of all primary studies and review articles found trials up to 25 March 2015. The most recent search for trials for the current update was conducted on 29 October 2019.

SELECTION CRITERIA

We included parallel randomised controlled trials, irrespective of blinding or duration, that evaluated sublingual immunotherapy versus placebo or as an add-on to standard asthma management. We included both adults and children with asthma of any severity and with any allergen-sensitisation pattern. We included studies that recruited participants with asthma, rhinitis, or both, providing at least 80% of trial participants had a diagnosis of asthma. We selected outcomes to reflect recommended outcomes for asthma clinical trials and those most important to people with asthma. Primary outcomes were asthma exacerbations requiring a visit to the emergency department (ED) or admission to hospital, validated measures of quality of life, and all-cause serious adverse events (SAEs). Secondary outcomes were asthma symptom scores, exacerbations requiring systemic corticosteroids, response to provocation tests, and dose of inhaled corticosteroids (ICS).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results for included trials, extracted numerical data, and assessed risk of bias, all of which were cross-checked for accuracy. Any disagreements were resolved by discussion. We analysed dichotomous data as odds ratios (ORs) or risk differences (RDs) using study participants as the unit of analysis; we analysed continuous data as mean differences (MDs) or standardised mean differences (SMDs) using random-effects models. We considered the strength of evidence for all primary and secondary outcomes using the GRADE approach.

MAIN RESULTS

Sixty-six studies met the inclusion criteria for this update, including 52 studies from the original review. Most studies were double-blind and placebo-controlled, varied in duration from one day to three years, and recruited participants with mild or intermittent asthma, often with comorbid allergic rhinitis. Twenty-three studies recruited adults and teenagers; 31 recruited only children; three recruited both; and nine did not specify. The pattern of reporting and results remained largely unchanged from the original review despite 14 further studies and a 50% increase in participants studied (5077 to 7944). Reporting of primary efficacy outcomes to measure the impact of SLIT on asthma exacerbations and quality of life was infrequent, and selective reporting may have had a serious effect on the completeness of the evidence; 16 studies did not contribute any data, and a further six studies could only be included in a post hoc analysis of all adverse events. Allocation procedures were generally not well described; about a quarter of the studies were at high risk of performance or detection bias (or both); and participant attrition was high or unknown in around half of the studies. The primary outcome in most studies did not align with those of interest to the review (mostly asthma or rhinitis symptoms), and only two small studies reported our primary outcome of exacerbations requiring an ED or hospital visit; the pooled estimate from these studies suggests SLIT may reduce exacerbations compared with placebo or usual care, but the evidence is very uncertain (OR 0.35, 95% confidence interval (CI) 0.10 to 1.20; n = 108; very low-certainty evidence). Nine studies reporting quality of life could not be combined in a meta-analysis and, whilst the direction of effect mostly favoured SLIT, the effects were often uncertain and small. SLIT likely does not increase SAEs compared with placebo or usual care, and analysis by risk difference suggests no more than 1 in 100 people taking SLIT will have a serious adverse event (RD -0.0004, 95% CI -0.0072 to 0.0064; participants = 4810; studies = 29; moderate-certainty evidence). Regarding secondary outcomes, asthma symptom and medication scores were mostly measured with non-validated scales, which precluded meaningful meta-analysis or interpretation, but there was a general trend of SLIT benefit over placebo. Changes in ICS use (MD -17.13 µg/d, 95% CI -61.19 to 26.93; low-certainty evidence), exacerbations requiring oral steroids (studies = 2; no events), and bronchial provocation (SMD 0.99, 95% CI 0.17 to 1.82; low-certainty evidence) were not often reported. Results were imprecise and included the possibility of important benefit or little effect and, in some cases, potential harm from SLIT. More people taking SLIT had adverse events of any kind compared with control (OR 1.99, 95% CI 1.49 to 2.67; high-certainty evidence; participants = 4251; studies = 27), but events were usually reported to be transient and mild. Lack of data prevented most of the planned subgroup and sensitivity analyses.

AUTHORS' CONCLUSIONS

Despite continued study in the field, the evidence for important outcomes such as exacerbations and quality of life remains too limited to draw clinically useful conclusions about the efficacy of SLIT for people with asthma. Trials mostly recruited mixed populations with mild and intermittent asthma and/or rhinitis and focused on non-validated symptom and medication scores. The review findings suggest that SLIT may be a safe option for people with well-controlled mild-to-moderate asthma and rhinitis who are likely to be at low risk of serious harm, but the role of SLIT for people with uncontrolled asthma requires further evaluation.

Is immunotherapy with fungal vaccines effective?

PURPOSE OF REVIEW

Although allergen immunotherapy (AIT) for fungi has been performed for many years, evidence clearly demonstrating its clinical benefit are still lacking. Here, we reviewed the available studies assessing efficacy and safety of AIT for molds.

RECENT FINDINGS

Studies on AIT for fungi were performed only for the two predominating mold species in the external environment, namely Cladosporium and Alternaria. There is no evidence for other mold species. Recent finding in the literature are lacking; the 2 most recent studies on AIT for molds were published in 2011. Overall, 13 studies were identified (the first was published in 1986), but only nine of these compared AIT to placebo. The studies are small (median study sample size, 27 patients) and of low quality, owing to several defects leading to moderate-to-high risk of bias. Symptoms improvement and medication use reduction, which are the main outcome measures of the studies, were inconsistently demonstrated. There are some concerns about safety with Cladosporium extracts, whereas vaccines with Alternaria extracts seem to be safe and well tolerated.

SUMMARY

Low strength evidence suggests that mold AIT is efficacious for the treatment of respiratory allergies. High-quality studies with an adequate sample size are needed.

EAACI Allergen Immunotherapy User's Guide

Allergen immunotherapy is a cornerstone in the treatment of allergic children. The clinical efficiency relies on a well-defined immunologic mechanism promoting regulatory T cells and downplaying the immune response induced by allergens. Clinical indications have been well documented for respiratory allergy in the presence of rhinitis and/or allergic asthma, to pollens and dust mites. Patients who have had an anaphylactic reaction to hymenoptera venom are also good candidates for allergen immunotherapy. Administration of allergen is currently mostly either by subcutaneous injections or by sublingual administration. Both methods have been extensively studied and have pros and cons. Specifically in children, the choice of the method of administration according to the patient's profile is important. Although allergen immunotherapy is widely used, there is a need for improvement. More particularly, biomarkers for prediction of the success of the treatments are needed. The strength and efficiency of the immune response may also be boosted by the use of better adjuvants. Finally, novel formulations might be more efficient and might improve the patient's adherence to the treatment. This user's guide reviews current knowledge and aims to provide clinical guidance to healthcare professionals taking care of children undergoing allergen immunotherapy.

Efficacy and safety of allergen immunotherapy in patients with allergy to molds: A systematic review

BACKGROUND

Allergen immunotherapy (AIT) with mould extracts has been performed for many years but the final demonstration of its clinical efficacy is still missing, due to the small number of studies and their inconsistent results.

OBJECTIVE

To systematically review efficacy and safety of AIT for the treatment of respiratory allergies to moulds.

DESIGN

The primary outcomes were safety and reduction of symptoms (Symptom Score, SS) and medication use (Medication Score, MS) in patients treated with AIT compared to controls. 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.

DATA SOURCES

Medline, Web of Science and the Cochrane Library (through September 2017) supplemented with manual searches of reference lists.

ELIGIBILITY CRITERIA

Randomized studies of intervention comparing AIT to placebo/pharmacotherapy. Studies not reporting on our outcome of interest or without a control population were excluded.

RESULTS

Nine studies (168 children, 99 adults; median sample size, 27) met the inclusion criteria. The risk of bias was moderate-to-high in all but one study. Low strength evidence supports the assumption that AIT is effective in reducing symptoms and medication use, with only four of nine studies reporting higher benefit of AIT vs. comparators. The highest benefit of AIT compared to pharmacotherapy/placebo was reported in studies with a longer follow-up (SMD for MS from -3.96 to -3.97 in favour of AIT) and low risk of bias (VAS for SS: 66.3 ± 13 in AIT group; 186.6 ± 39 in comparators; P < 0.05). No difference was reported with respect to study sample size, route of administration, age of participants. Generalised adverse reactions were reported in 12.5% of participants treated with sublingual immunotherapy, and 37.2% of participants treated with subcutaneous immunotherapy.

CONCLUSIONS

Low strength evidence suggests that mould AIT is efficacious for the treatment of respiratory allergies. High-quality studies with an adequate sample size are needed.

Sublingual Immunotherapy Dosing Regimens: What Is Ideal?

Sublingual immunotherapy (SLIT) is a treatment for allergic respiratory diseases that has demonstrated efficacy and safety. Several formulations of SLIT are now available worldwide for treatment of allergic rhinitis (AR). Grass tablets containing 15 to 25 μg of group 5 major allergen reduced combined AR symptoms and medication use by 23% to 41% in 3 treatment years and 2 follow-up years. Ragweed pollen tablets (12 μg of Ambrosia artemisiifolia 1) and liquid extracts (50 μg of Ambrosia artemisiifolia 1) reduced combined AR symptoms and medication use by 26% and 43%, respectively. House dust mite tablets containing 300 index of reactivity (16 μg of Dermatophagoides pteronyssinus 1 and 68 μg of Dermatophagoides farinae 1) reduced AR symptoms by 17.9% and 17.0% in 1 treatment year and 1 follow-up year, respectively. A different house dust mite tablet (12 standardized quality house dust mite) was able to reduce the risk of asthma exacerbation compared with placebo (hazard ratio, 0.69; 95% CI, 0.50-0.96). Most adverse events were local and mild to moderate in severity. For SLIT products reviewed herein, effective doses range from 1.12 to 84 μg of major allergen(s). However, allergen content is not uniformly standardized, can be expressed in arbitrary or proprietary units (depending on the manufacturer), and assays for determination of allergen content are highly variable. Thus, results from one study of a given product cannot be extrapolated to other products. Despite these limitations, this Clinical Management Review aims to provide practitioners with relevant information on the dosing of selected SLIT formulations in the treatment of allergic respiratory disease.

Immunotherapy of mold allergy: A review

Mold allergies are common, mainly target the respiratory tract and present as allergic rhinitis and/or bronchial asthma. Molds include a large group of different allergens that induce all types of allergic reactions. Allergen specific immunotherapies (AITs) to molds are common; however, at the present time, they are limited to Alternaria. This review presents not only the benefits but also the problems with such types of AIT based on the literature and our experience.

Allergen-specific immunotherapy in pediatric allergic asthma

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

Intralymphatic immunotherapy of pollen-induced rhinoconjunctivitis: a double-blind placebo-controlled trial

Background

Allergen-specific immunotherapy represents the only disease-modifying treatment for allergic diseases. We and others have previously demonstrated that intralymphatic immunotherapy (ILIT), a less time-consuming alternative to conventional subcutaneous immunotherapy (SCIT), is safe and effective. However, this has recently been disputed. The aim of this study was therefore to expand our previous trial, further assessing the safety and efficacy of ILIT.

Methods

Thirty-six patients with pollen-induced rhinoconjunctivitis were randomised to receive three intralymphatic inguinal injections of active allergen (1000 SQ-U birch- or grass-pollen) or placebo. Clinical effects, safety and circulating immunological markers were assessed before, 4 weeks after treatment and at the end of the consecutive pollen season.

Results

No moderate or severe reactions were recorded following ILIT. Patients receiving active ILIT experienced a significant improvement in self-recorded seasonal allergic symptoms, as compared to placebo (p = 0.05). In a subgroup of these patients (“improved”), a reduction in nasal symptoms following nasal allergen provocation was also demonstrated. No changes in total IgE or IgG₄ were found. However, the affinity of allergen specific IgG₄ following active treatment was significantly increased, as compared to non-improved patients (p = 0.04). This could be correlated with clinical improvement, on an individual level.

Conclusions

This double-blinded placebo-controlled study confirms that ILIT is a safe and effective treatment for pollen-induced rhinoconjunctivitis, markedly reducing seasonal allergic symptoms.

Trial registration

EudraCT: 2009-016815-39

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-016-0324-9) contains supplementary material, which is available to authorized users.

Clinical Evaluation and Management of Patients with Suspected Fungus Sensitivity

Fungus-sensitized patients usually present with symptoms that are similar to symptoms presented by those who are sensitized to other aeroallergens. Therefore, diagnosis and management should follow the same pathways used for patients with allergic conditions in general. The physician should consider that a relationship between fungal exposure and symptoms is not necessarily caused by an IgE-mediated mechanism, even when specific fungal IgE is detected. Until recently, IgE-mediated allergy has been documented only for a limited number of fungi. We propose a series of questions to be used to identify symptoms that occur in situations with high fungal exposure and a limited skin-prick-test panel (Alternaria, Cladosporium, Penicillium, Aspergillus, Candida) that can be amplified only in cases of high suspicion of other fungal exposure (eg, postfloods). We also review in vitro testing for fungi-specific IgE. Treatment includes environmental control, medical management, and, when appropriate, specific immunotherapy. Low-quality evidence exists supporting the use of subcutaneous immunotherapy for Alternaria to treat allergic rhinitis and asthma, and very low quality evidence supports the use of subcutaneous immunotherapy for Cladosporium and sublingual immunotherapy for Alternaria. As is the case for many allergens, evidence for immunotherapy with other fungal extracts is lacking. The so-called toxic mold syndrome is also briefly discussed.

Sublingual immunotherapy for asthma

BACKGROUND

Asthma is a common long-term respiratory disease affecting approximately 300 million people worldwide. Approximately half of people with asthma have an important allergic component to their disease, which may provide an opportunity for targeted treatment. Sublingual immunotherapy (SLIT) aims to reduce asthma symptoms by delivering increasing doses of an allergen (e.g. house dust mite, pollen extract) under the tongue to induce immune tolerance. However, it is not clear whether the sublingual delivery route is safe and effective in asthma.

OBJECTIVES

To assess the efficacy and safety of sublingual immunotherapy compared with placebo or standard care for adults and children with asthma.

SEARCH METHODS

We identified trials from the Cochrane Airways Group Specialised Register (CAGR), ClinicalTrials.gov (www.ClinicalTrials.gov), the World Health Organization (WHO) trials portal (www.who.int/ictrp/en/) and reference lists of all primary studies and review articles. The search is up to date as of 25 March 2015.

SELECTION CRITERIA

We included parallel randomised controlled trials (RCTs), irrespective of blinding or duration, that evaluated sublingual immunotherapy versus placebo or as an add-on to standard asthma management. We included both adults and children with asthma of any severity and with any allergen-sensitisation pattern. We included studies that recruited participants with asthma, rhinitis, or both, providing at least 80% of trial participants had a diagnosis of asthma.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results for included trials, extracted numerical data and assessed risk of bias, all of which were cross-checked for accuracy. We resolved disagreements by discussion.We analysed dichotomous data as odds ratios (ORs) or risk differences (RDs) using study participants as the unit of analysis; we analysed continuous data as mean differences (MDs) or standardised mean differences (SMDs) using random-effects models. We rated all outcomes using GRADE (Grades of Recommendation, Assessment, Development and Evaluation) and presented results in the 'Summary of findings' table.

MAIN RESULTS

Fifty-two studies met our inclusion criteria, randomly assigning 5077 participants to comparisons of interest. Most studies were double-blind and placebo-controlled, but studies varied in duration from one day to three years. Most participants had mild or intermittent asthma, often with co-morbid allergic rhinitis. Eighteen studies recruited only adults, 25 recruited only children and several recruited both or did not specify (n = 9).With the exception of adverse events, reporting of outcomes of interest to this review was infrequent, and selective reporting may have had a serious effect on the completeness of the evidence. Allocation procedures generally were not well described, about a quarter of the studies were at high risk of bias for performance or detection bias or both and participant attrition was high or unknown in around half of the studies.One short study reported exacerbations requiring a hospital visit and observed no adverse events. Five studies reported quality of life, but the data were not suitable for meta-analysis. Serious adverse events were infrequent, and analysis using risk differences suggests that no more than 1 in 100 are likely to suffer a serious adverse event as a result of treatment with SLIT (RD 0.0012, 95% confidence interval (CI) -0.0077 to 0.0102; participants = 2560; studies = 22; moderate-quality evidence).Within secondary outcomes, wide but varied reporting of largely unvalidated asthma symptom and medication scores precluded meaningful meta-analysis; a general trend suggested SLIT benefit over placebo, but variation in scales meant that results were difficult to interpret.Changes in inhaled corticosteroid use in micrograms per day (MD 35.10 mcg/d, 95% CI -50.21 to 120.42; low-quality evidence), exacerbations requiring oral steroids (studies = 2; no events) and bronchial provocation (SMD 0.69, 95% CI -0.04 to 1.43; very low-quality evidence) were not often reported. This led to many imprecise estimates with wide confidence intervals that included the possibility of both benefit and harm from SLIT.More people taking SLIT had adverse events of any kind compared with control (OR 1.70, 95% CI 1.21 to 2.38; low-quality evidence; participants = 1755; studies = 19), but events were usually reported to be transient and mild.Lack of data prevented most of the planned subgroup and sensitivity analyses.

AUTHORS' CONCLUSIONS

Lack of data for important outcomes such as exacerbations and quality of life and use of different unvalidated symptom and medication scores have limited our ability to draw a clinically useful conclusion. Further research using validated scales and important outcomes for patients and decision makers is needed so that SLIT can be properly assessed as clinical treatment for asthma. Very few serious adverse events have been reported, but most studies have included patients with intermittent or mild asthma, so we cannot comment on the safety of SLIT for those with moderate or severe asthma. SLIT is associated with increased risk of all adverse events.

Dosing of sublingual immunotherapy for allergic rhinitis: evidence-based review with recommendations

BACKGROUND

Since the mid 1980s, the clinical use of sublingual immunotherapy (SLIT) has dramatically increased. However, 1 of the primary barriers to providing SLIT is lack of a published dosing recommendations. The purpose of this work is to provide a range of effective SLIT dosing based upon a rigorous review of the existing evidence base. An appendix with SLIT dosing recommendations is also included.

METHODS

A comprehensive search of the past 25 years of the medical literature using PubMed was performed for specific antigens. Inclusion criteria for articles included: randomized, placebo-controlled studies of SLIT, studies with clinical allergic rhinitis outcomes, and dosing units available to determine the micrograms per month of major allergen administered. The extracted data was used to compile a range of effective SLIT dosing for individual antigens.

RESULTS

Seventy-five articles met the inclusion criteria, providing a range of effective dosing for some allergens. There was commonly a wide range in doses for particular antigens between the individual studies. For some antigens, there was significant overlap in dosage amount between studies showing efficacy and lack of efficacy. Clinical trials meeting inclusion criteria are not available for many allergens.

CONCLUSION

This study provided a comprehensive review of the published sublingual dosing ranges for specific antigens. The review provided a range of effective sublingual doses for some allergens, whereas for other allergens there was insufficient published data to determine specific doses. Recommendations for SLIT dosing were produced based on the data revealed in the review and expert opinion.

Sublingual immunotherapy: World Allergy Organization position paper 2013 update

We have prepared this document, "Sublingual Immunotherapy: World Allergy Organization Position Paper 2013 Update", according to the evidence-based criteria, revising and updating chapters of the originally published paper, "Sublingual Immunotherapy: World Allergy Organization Position Paper 2009", available at http://www.waojournal.org. Namely, these comprise: "Mechanisms of sublingual immunotherapy;" "Clinical efficacy of sublingual immunotherapy" - reporting all the data of all controlled trials published after 2009; "Safety of sublingual immunotherapy" - with the recently published Grading System for adverse reactions; "Impact of sublingual immunotherapy on the natural history of respiratory allergy" - with the relevant evidences published since 2009; "Efficacy of SLIT in children" - with detailed analysis of all the studies; "Definition of SLIT patient selection" - reporting the criteria for eligibility to sublingual immunotherapy; "The future of immunotherapy in the community care setting"; "Methodology of clinical trials according to the current scientific and regulatory standards"; and "Guideline development: from evidence-based medicine to patients' views" - including the evolution of the methods to make clinical recommendations.Additionally, we have added new chapters to cover a few emerging crucial topics: "Practical aspects of schedules and dosages and counseling for adherence" - which is crucial in clinical practice for all treatments; "Perspectives and new approaches" - including recombinant allergens, adjuvants, modified allergens, and the concept of validity of the single products. Furthermore, "Raising public awareness about sublingual immunotherapy", as a need for our patients, and strategies to increase awareness of allergen immunotherapy (AIT) among patients, the medical community, all healthcare stakeholders, and public opinion, are also reported in detail.

Allergen-specific immunotherapy for allergic rhinitis in the elderly: is it never too late?

Evaluation of: Bozek A, Ignasiak B, Filipowska B, Jarzab J. House dust mite sublingual immunotherapy: a double-blind, placebo-controlled study in elderly patients with allergic rhinitis. Clin. Exp. Allergy 43(2), 242-248 (2013). There is a well-accepted tenet in allergen-specific immunotherapy (SIT), especially for respiratory allergies such as rhinitis and asthma: this approach should be, in general, reserved for the pediatric population and young adults. This belief is based on the fact that SIT is considered the only therapy able to modify the course of allergic diseases. In the case of allergic rhinitis, for example, SIT could reduce the risk of asthma developing. Therefore, SIT is evaluated with 'the sooner the better' conviction. In elderly people with respiratory allergies, the 'course' of the disease is considered too advanced and therefore the room and therapeutic value of SIT is considered very limited. Bozek et al. evaluated the clinical efficacy of sublingual SIT (SLIT) with house dust mite (HDM) extracts in elderly (age >60 years) patients with a long history of allergic rhinitis due to HDM allergen exposure. In a 3-year double-blind placebo-controlled study, SLIT was able to significantly reduce the nose-related symptoms and the medication score. The conclusions of the authors were that SLIT with HDM allergens resulted in a significant clinical improvement in the active group compared with the placebo group, particularly during the period of the year in which the heating would be on. This therapy was well tolerated. These observations may lead to the more frequent use of SLIT immunotherapy in the elderly.

Will sublingual immunotherapy offer benefit for asthma?

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

Pediatric sublingual immunotherapy efficacy: evidence analysis, 2009-2012

OBJECTIVE

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

DATA SOURCES

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

STUDY SELECTIONS

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

RESULTS

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

CONCLUSION

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