Allergic rhinitis due to house dust mites: evaluation of the efficacy of specific sublingual immunotherapy

The evidence for commercial house dust mite immunotherapy products: A pragmatic systematic review with narrative synthesis

House dust mite (HDM) allergen immunotherapy (AIT) has an established role in the treatment of perennial allergic rhinitis (AR) and allergic asthma (AA) triggered by HDM sensitization. We aimed to identify all double-blind, randomized, placebo-controlled trials of HDM AIT for the treatment of AR and AA in humans and to summarize the evidence for AIT products that are currently manufactured and available for clinical use. A total of 56 eligible double-blind, randomized, placebo-controlled trials of HDM AIT for the treatment of AA and/or AR in humans fit the inclusion criteria and investigated a total of 14 commercial AIT products; together, the 56 studies enrolled a total of 14,619 patients. Of the 56 studies, 39 studies investigated the current manufacturer-recommended maintenance dose (MRMD) of the product, and 17 investigated other doses. We identified 39 studies (12,539 patients randomized) for 8 sublingual immunotherapy (SLIT) products and 17 studies (2,080 patients randomized) for subcutaneous immunotherapy products. For AR, 3 products, the ALK 12 standardized-quality (SQ-HDM) SLIT tablet, the ALK 6 SQ-HDM tablet, and the SG 300 index of reactivity SLIT tablet, had both dose-finding studies (DFSs) and phase III definitive studies (DSs) to demonstrate efficacy of the MRMD of the product. For AA, 2 products, the ALK 12 SQ-HDM SLIT tablet and the ALK 6 SQ-HDM tablet, had both DFSs and DSs for the MRMD. No subcutaneous immunotherapy product had a paired DFS and DS supporting the MRMD. A total of 30 studies of products no longer commercially manufactured were excluded. This study will help to inform clinical care and product selection for the treatment of HDM-induced AR and AA.

Immunologic modification in mono- and poly-sensitized patients after sublingual immunotherapy

OBJECTIVES/HYPOTHESIS

To compare immunologic modification and treatment outcomes after 2 years of sublingual immunotherapy (SLIT) with house dust mite extracts (HDM) between monosensitized and polysensitized patients with allergic rhinitis.

STUDY DESIGN

Retrospective cohort study.

METHODS

Among the patients who were prospectively enrolled in the SLIT cohort study, patients with allergic rhinitis who were sensitized to HDM and treated with SLIT for at least 2 years were studied. All participants underwent serologic tests at baseline and after SLIT to evaluate changes in immunologic parameters. The total nasal symptom score (TNSS) was measured before and after SLIT, and effective and less effective responder groups were categorized depending on whether patients had a TNSS reduction of 50%, as compared with baseline.

RESULTS

The increase in Dermatophagoides pteronyssinus and Dermatophagoides farinae specific immunoglobulin G4 levels was significantly higher in monosensitized patients than in polysensitized patients (P = .020 and P = .005, respectively). The TNSS significantly improved after SLIT in both the monosensitized and polysensitized groups (P < .001 in both groups). However, the difference in the changes in TNSS from baseline was not significant between the two groups (P = .374).

CONCLUSIONS

This study demonstrated different immunologic modifications after SLIT between monosensitized and polysensitized patients. However, patients in the polysensitized group who were treated with single-allergen SLIT experienced clinical improvement in TNSS that was comparable with that in the monosensitized group despite demonstrating different immunologic changes.

LEVEL OF EVIDENCE

2b Laryngoscope, 129:E170-E177, 2019.

Sublingual allergen immunotherapy for respiratory allergy: a systematic review

The objective of the systematic review is to provide complete and updated information on efficacy and safety of sublingual immunotherapy (SLIT) formulations for the treatment of allergic respiratory diseases (ARDs). The literature search was conducted on PubMed database, involving double-blind, randomized clinical trials published between January 1992 and 2018, written in English, and performed in humans. The number of articles finally selected for review was 112. Data from the majority of properly controlled clinical trials demonstrate that SLIT is effective not only with short-term use (first year) but also with long-term use (up to the third year of active therapy), for treating ARDs in children and adults. Both continuous and discontinuous schemes of administration showed significant reductions in symptom and medication scores. Moreover, a SLIT-induced disease-modifying effect has been documented mainly with grass pollen extracts, since improvement is maintained during at least 2 years of follow-up after a 3-year treatment period. Additionally, allergen immunotherapy should also be considered a preventive strategy, especially for decreasing bronchial asthma incidence in children and adolescents with allergic rhinitis treated with SLIT. This therapy is also safe, producing only a few mainly local and mild-to-moderate adverse events, and usually self-limited in time. The registration and authorization of allergen SLIT preparations (grasses and house-dust mite tablets) as drugs by regulatory agencies, such as the United States Food and Drug Administration (FDA) and the European Medicines Agency (EMA), has represented a landmark in allergy immunotherapy research. Further long-term studies, specially designed with allergens other than grass pollen or house-dust mites, not only in allergic rhinoconjunctivitis but also on asthmatic subjects, as well as studies comparing different administration schedules and/or routes, are required in order to continue the progress in the modern development of this particularly promising therapy.

Sublingual immunotherapy for treating adult patients with allergic rhinitis induced by house dust mite among Chinese Han population: A retrospective study

The objective of this retrospective study was to evaluate the efficacy and safety of sublingual immunotherapy (SLIT) for treating adult patients with allergic rhinitis (AR) induced by house dust mite (HDM) among Chinese Han population.A total of 201 adult patients with AR induced by HDM were included. All of them received SLIT treatment. The outcomes consisted of AR symptoms, and quality of life. In addition, any adverse events were also recorded in this study.Compared with the AR symptoms and quality of life before the treatment, significant differences were found after 1-year treatment (P < .01), and 2-year treatment (P < .01). Additionally, only mild and acceptable adverse events were observed in this study.This study demonstrated that SLIT may be efficacious and safety for adult patients with HDM induced by AR among Chinese Han population.

A randomized, double-blind, placebo controlled trial of sublingual immunotherapy with house-dust mite extract for allergic rhinitis

OBJECTIVE

This study was designed to evaluate the efficacy and safety of sublingual immunotherapy (SLIT) with house-dust mite (HDM) extract in Chinese patients with HDM-induced allergic rhinitis (AR).

METHODS

A randomized, double-blind, placebo controlled trial was conducted with the outpatients of the Eye, Ear, Nose, and Throat Hospital, Fudan University. Forty-eight patients were eligible for randomization to SLIT with a mixture of Dermatophagoides pteronyssinus and Dermatophagoides farinae extract or placebo for 1 year. The primary outcome measures for efficacy were the total nasal symptom score (TNSS) and the individual nasal symptom score. Secondary end points were allergic conjunctivitis scores (ACS) and medication scores (MS). Adverse events (AE) also were monitored.

RESULTS

Intragroup analysis demonstrated a significant improvement in the active treatment group for individual nasal symptom score and TNSS (p < 0.05), although no improvement was observed in the placebo group of congestion, sneezing, and itching (p > 0.05). Furthermore, the ACS and MS in the active treatment group also statistically decreased (p < 0.05). In addition, the active treatment had significant effects on relieving nasal symptoms both in adults and children (p < 0.05), and no statistical difference was observed between these two subgroups (p > 0.05). AEs that occurred ranged from mild to moderate, and no severe systematic reactions were observed.

CONCLUSION

SLIT with a mixture of HDM extract significantly relieved allergy symptoms and reduced the need for antiallergic drugs, which indicated the superiority of active treatment over placebo for patients with HDM-induced AR. However, due to the limited sample size, the findings need to be further confirmed.

Changes in skin reactivity and associated factors in patients sensitized to house dust mites after 1 year of allergen-specific immunotherapy

Background

Allergen-specific immunotherapy (SIT) can significantly improve symptoms and reduce the need for symptomatic medication.

Objective

The aim of this study was to investigate changes in skin reactivity to house dust mites (HDMs) as an immunologic response and associated factors after 1 year of immunotherapy.

Methods

A total of 80 patients with allergic airway diseases who received subcutaneous SIT with HDMs from 2009 to 2014 were evaluated. The investigated parameters were basic demographic characteristics, skin reactivity and specific IgE for HDM, serum total IgE level, blood eosinophil counts, and medication score.

Results

The mean levels of skin reactivity to HDMs, blood eosinophil counts, and medication scores after 1 year were significantly reduced from baseline. In univariate comparison of the changes in skin reactivity to HDMs, age ≤30 years, HDMs only as target of immunotherapy, and high initial skin reactivity (≥2) to HDMs were significantly associated with the reduction in skin test reactivity. In multivariate analysis, high initial skin reactivity and HDMs only as target allergens were significantly associated with changes in skin reactivity to HDMs. In the receiver operating characteristic curve of the initial mean skin reactivity to HDMs for more than 50% reduction, the optimal cutoff value was 2.14.

Conclusion

This study showed significant reductions in allergen skin reactivity to HDMs after 1 year of immunotherapy in patients sensitized to HDMs. The extent of initial allergen skin reactivity and only HDMs as target allergen were important predictive factors for changes in skin reactivity.

Efficacy of house dust mite sublingual immunotherapy tablet in North American adolescents and adults in a randomized, placebo-controlled trial

BACKGROUND

The house dust mite (HDM) sublingual immunotherapy (SLIT) tablet (MK-8237; Merck & Co, Kenilworth, NJ/ALK-Abelló, Hørsholm, Denmark) has demonstrated beneficial effects on allergic rhinoconjunctivitis and asthma outcomes in European trials.

OBJECTIVE

This is the first trial to assess the efficacy/safety of HDM SLIT-tablets in North American subjects with HDM-induced allergic rhinitis with or without conjunctivitis (AR/C).

METHODS

In this double-blind, multicenter trial (NCT01700192) 1482 subjects (aged ≥12 years) with HDM-induced AR/C with or without asthma were randomized to a daily SQ HDM SLIT-tablet (12 SQ-HDM dose) or placebo for up to approximately 52 weeks. A rhinitis daily symptom score (DSS; 4 nasal symptoms, maximum score = 12) of 6 or greater, or 5 or greater with 1 symptom being severe, on 5 of 7 consecutive days before randomization was required. The primary end point was the average total combined rhinitis score, which was defined as the rhinitis DSS plus rhinitis daily medication score (DMS), during the last 8 treatment weeks.

RESULTS

Treatment with 12 SQ-HDM improved the total combined rhinitis score by 17% (95% CI, 10% to 25%) versus placebo. Improvements versus placebo in the secondary end points of average rhinitis DSS, rhinitis DMS, total combined rhinoconjunctivitis score, and visual analog scale-assessed AR/C symptoms were 16%, 18%, 17%, and 16%, respectively. All nominal P values were less than .001 versus placebo, except rhinitis DMS (P = 0.15). No treatment-related adverse events meeting the International Council on Harmonization definition of a serious adverse event were reported; 1 nonserious treatment-related systemic allergic reaction occurred (assessed as moderate intensity) at first administration under medical supervision and was treated with epinephrine.

CONCLUSIONS

In the first North American trial of use of a SLIT-tablet for HDM allergy, 12 SQ-HDM was well tolerated and improved HDM-induced rhinitis symptoms in adults and adolescents.

Specific allergen immunotherapy for the treatment of atopic eczema

BACKGROUND

Specific allergen immunotherapy (SIT) is a treatment that may improve disease severity in people with atopic eczema (AE) by inducing immune tolerance to the relevant allergen. A high quality systematic review has not previously assessed the efficacy and safety of this treatment.

OBJECTIVES

To assess the effects of specific allergen immunotherapy (SIT), including subcutaneous, sublingual, intradermal, and oral routes, compared with placebo or a standard treatment in people with atopic eczema.

SEARCH METHODS

We searched the following databases up to July 2015: the Cochrane Skin Group Specialised Register, CENTRAL in the Cochrane Library (Issue 7, 2015), MEDLINE (from 1946), EMBASE (from 1974), LILACS (from 1982), Web of Science™ (from 2005), the Global Resource of EczemA Trials (GREAT database), and five trials databases. We searched abstracts from recent European and North American allergy meetings and checked the references of included studies and review articles for further references to relevant trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of specific allergen immunotherapy that used standardised allergen extracts in people with AE.

DATA COLLECTION AND ANALYSIS

Two authors independently undertook study selection, data extraction (including adverse effects), assessment of risk of bias, and analyses. We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We identified 12 RCTs for inclusion in this review; the total number of participants was 733. The interventions included SIT in children and adults allergic to either house dust mite (10 trials), grass pollen, or other inhalant allergens (two trials). They were administered subcutaneously (six trials), sublingually (four trials), orally, or intradermally (two trials). Overall, the risk of bias was moderate, with high loss to follow up and lack of blinding as the main methodological concern.Our primary outcomes were 'Participant- or parent-reported global assessment of disease severity at the end of treatment'; 'Participant- or parent-reported specific symptoms of eczema, by subjective measures'; and 'Adverse events, such as acute episodes of asthma or anaphylaxis'. SCORing Atopic Dermatitis (SCORAD) is a means of measuring the effect of atopic dermatitis by area (A); intensity (B); and subjective measures (C), such as itch and sleeplessness, which we used.For 'Participant- or parent-reported global assessment of disease severity at the end of treatment', one trial (20 participants) found improvement in 7/9 participants (78%) treated with the SIT compared with 3/11 (27%) treated with the placebo (risk ratio (RR) 2.85, 95% confidence interval (CI) 1.02 to 7.96; P = 0.04). Another study (24 participants) found no difference: global disease severity improved in 8/13 participants (62%) treated with the SIT compared with 9/11 (81%) treated with the placebo (RR 0.75, 95% CI 0.45 to 1.26; P = 0.38). We did not perform meta-analysis because of high heterogeneity between these two studies. The quality of the evidence was low.For 'Participant- or parent-reported specific symptoms of eczema, by subjective measures', two trials (184 participants) did not find that the SIT improved SCORAD part C (mean difference (MD) -0.74, 95% CI -1.98 to 0.50) or sleep disturbance (MD -0.49, 95% CI -1.03 to 0.06) more than placebo. For SCORAD part C itch severity, these two trials (184 participants) did not find that the SIT improved itch (MD -0.24, 95% CI -1.00 to 0.52). One other non-blinded study (60 participants) found that the SIT reduced itch compared with no treatment (MD -4.20, 95% CI -3.69 to -4.71) and reduced the participants' overall symptoms (P < 0.01), but we could not pool these three studies due to high heterogeneity. The quality of the evidence was very low.Seven trials reported systemic adverse reactions: 18/282 participants (6.4%) treated with the SIT had a systemic reaction compared with 15/210 (7.1%) with no treatment (RR 0.78, 95% CI 0.41 to 1.49; the quality of the evidence was moderate). The same seven trials reported local adverse reactions: 90/280 participants (32.1%) treated with the SIT had a local reaction compared with 44/204 (21.6%) in the no treatment group (RR 1.27, 95% CI 0.89 to 1.81). As these had the same study limitations, we deemed the quality of the evidence to also be moderate.Of our secondary outcomes, there was a significant improvement in 'Investigator- or physician-rated global assessment of disease severity at the end of treatment' (six trials, 262 participants; RR 1.48, 95% CI 1.16 to 1.88). None of the studies reported our secondary outcome 'Parent- or participant-rated eczema severity assessed using a published scale', but two studies (n = 184), which have been mentioned above, used SCORAD part C, which we included as our primary outcome 'Participant- or parent-reported specific symptoms of eczema, by subjective measures'.Our findings were generally inconclusive because of the small number of studies. We were unable to determine by subgroup analyses a particular type of allergen or a particular age or level of disease severity where allergen immunotherapy was more successful. We were also unable to determine whether sublingual immunotherapy was associated with more local adverse reactions compared with subcutaneous immunotherapy.

AUTHORS' CONCLUSIONS

Overall, the quality of the evidence was low. The low quality was mainly due to the differing results between studies, lack of blinding in some studies, and relatively few studies reporting participant-centred outcome measures. We found limited evidence that SIT may be an effective treatment for people with AE. The treatments used in these trials were not associated with an increased risk of local or systemic reactions. Future studies should use high quality allergen formulations with a proven track record in other allergic conditions and should include participant-reported outcome measures.

The effects of house dust mite sublingual immunotherapy in patients with allergic rhinitis according to duration

BACKGROUND

The safety and efficacy of sublingual immunotherapy (SLIT) have been demonstrated in the recent 2 decades. However, the data is still mixed regarding the efficacy of house dust mite (HDM) SLIT. The objective of this work was to evaluate the different clinical efficacy SLIT in patients with allergic rhinitis (AR) according to different durations of treatment.

METHODS

A total of 500 subjects with HDM-induced AR were randomized to receive SLIT with Dermatophagoides farinae (Der.f) drops or pharmacotherapy with oral antihistamines. Patients in the SLIT group were further divided into SLIT1, SLIT2, and SLIT3 subgroups. After SLIT completion, a yearly follow-up visit was given to patients in the SLIT1 and SLIT2 subgroups. The total nasal symptom score (TNSS), the proportion of medication withdrawal, the visual analogue scale (VAS) score, and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scores were assessed at each monthly visit.

RESULTS

Comparing with the baseline value, TNSS, VAS, and RQLQ were significantly improved in 3 SLIT subgroups after treatment (p < 0.05). In addition, patients in SLIT3 subgroup achieved the highest proportion of medication withdrawal compared to the SLIT1 and SLIT2 subgroups (p < 0.05). After 1-year follow-up, no significant differences were observed in TNSS, VAS scores, and the proportion of medication withdrawal of SLIT1 and SLIT2 subgroups (p > 0.05) with respect to the completion value. No severe systemic adverse events (AEs) were reported.

CONCLUSION

The randomized study suggested that 3-year courses of SLIT in patients with AR was more efficacious than 1-year or 2-year courses. Furthermore, patients achieved 1-year long-term clinical benefits from HDM SLIT.

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.

Mite-Allergic Rhinitis: How to Evaluate Clinical Efficacy in Allergen-Specific Immunotherapy Trials?

House dust mite (HDM) allergen exposure is the most important cause of perennial allergic rhinitis and/or asthma. Although allergen-specific immunotherapy (AIT) with HDM is well established, published studies have been characterized by substantial heterogeneity in clinical endpoints. Standardization in measuring clinical efficacy is required. Moreover, when designing an AIT trial with HDM allergens, several considerations have to be taken into account. The history of HDM allergy is less clear cut than the typical history of pollen allergy. In addition, clinical features of HDM allergy may differ from those of pollen allergy. Moreover, although not easily measurable, fluctuation in allergen exposure may cause variation in symptom severity and determine the timing of assessment of clinical effects of HDM AIT. Key points 1. A combined symptom and medication score (CSMS) is recommended as standard for the primary endpoint in future house dust mite (HDM) allergen-specific immunotherapy trials. 2. The diagnosis of HDM allergy is based on a carefully taken history in combination with sensitization to HDM allergens. 3. Eye symptoms are less prominent in patients with HDM-induced allergic rhinitis. Nasal symptoms, but not eye symptoms, should be included in the CSMS and in symptom scores as well. 4. As methods to determine allergen exposure vary and the efficacy of environmental control is a matter of debate, a practical approach consists of restraining patients from implementing HDM-reducing measures, such as removing carpets and introducing anti-mite covers, after the start of the study. 5. Efficacy evaluation in the period with the highest exposure to mites is recommended.

Three-Year Follow-up Results of Sublingual Immunotherapy in Patients With Allergic Rhinitis Sensitized to House Dust Mites

Purpose

This study investigated the long-term efficacy, safety, and compliance associated with sublingual immunotherapy (SLIT) in Korean patients with allergic rhinitis sensitized to house dust mites.

Methods

This is a retrospective cohort study. A total of 164 patients who were sensitized to Dermatophagoides pteronyssinus and Dermatophagoides farinae and who received SLIT were enrolled between November 2007 and January 2010. Each patient was followed up using a diary card, on which a symptom score, rescue medication score, and adverse events (AEs) were recorded.

Results

All allergic rhinitis symptoms improved after 3 years of SLIT (P<0.05), and the rescue medication score decreased with time (P<0.05). The incidence of AEs associated with SLIT was 31% (51 of 164 patients) during the first month of therapy, and there were no severe AEs. The dropout rate was 19.5% (32 of 164 patients) during the first month, 34% (56 of 164 patients) after 6 months, and 41% (68 of 164 patients) after 1 year of SLIT. The 3-year compliance rate was approximately 40% (65 of 164 patients). The most common causes of dropout during the first month of SLIT were high cost and inconvenience. The improvement in allergic symptoms was the most common cause of dropout after 6 months.

Conclusions

Allergic symptoms significantly decreased after 1 year of SLIT treatment, and this effect was sustained after 2 or 3 years of treatment. By increasing compliance through patient education, the 3-year use of SLIT for house dust mite allergies may be effective in the management of allergic rhinitis.

A milestone in house dust-mite-allergen immunotherapy: the new sublingual tablet S-524101 (actair)

Subcutaneous allergen-specific immunotherapy has long been used in the treatment of allergic rhinitis and/or asthma and its efficacy has been confirmed. However, due to the discomfort of injections and the risk of severe adverse reactions, alternative routes of allergen administration have emerged. Delivery of allergens through the mucosal route had been proposed and investigated thoroughly, confirming the sublingual route to be the most efficacious. Later, the efficacy and safety of this route have been documented by numerous controlled trials both for house dust mite (HDM) and pollens. Recently, sublingual orodispersable grass pollen allergen tablets were in use followed by the newly developed HDM allergen tablets with satisfactory clinical results: Moreover, very recently 1 year of HDM tablet treatment was demonstrated to exert its clinical efficacy 1 year after discontinuation of tablet IT. The persistence of efficacy after only 1 year of treatment is a new and promising era. Currently, Sublingual Immunotherapy is the most easily administered and safe treatment option until more immunogenic, less allergenic and more efficient allergen extracts are developed.

Dropouts in sublingual allergen immunotherapy trials - a systematic review

Participant dropouts can reduce the power of allergen immunotherapy clinical trials. Evaluation of the dropout rate and reasons for dropout are important not only in the planning of clinical studies but are also relevant for adherence to immunotherapy in daily clinical practice. A systematic review was carried out in order to establish the overall dropout rate among published double-blind, placebo-controlled randomized clinical trials of sublingual immunotherapy for respiratory allergic diseases. Dropouts were analysed in regards to allergen, formulation, treatment schedule, participant age, study size, number of centres and type of allergic disease. Relative dropout rates in placebo and active groups as well as reasons for dropout were also assessed. A total of 81 studies, comprising 9998 patients, were included. Dropout rates in sublingual immunotherapy controlled studies do not appear to be a major problem with a composite dropout percentage of 14% (95% CI:11.9-16). Furthermore, they are not different for active compared to placebo-treated participants. This lends support to the positive clinical outcomes seen in meta-analyses of these trials.

Efficacy of sublingual immunotherapy for allergic asthma: retrospective meta-analysis of randomized, double-blind and placebo-controlled trials

BACKGROUND

Allergen-specific immunotherapy (SIT) is the only available curative choice with a disease-modifying effect against respiratory allergies. The efficacy of SIT via the sublingual route was demonstrated by a number of clinical trials. This meta-analysis was performed to investigate the clinical efficacy and safety of sublingual-specific immunotherapy (SLIT) for allergic asthma.

METHODS

PubMed, EMBASE and the Cochrane Central Register of Controlled Trials were searched for randomized, double-blind and placebo-controlled (DBPC) trials evaluating the efficacy and safety of SLIT on allergic asthma. Subgroup analyses were performed according to age, type of allergen and duration of SLIT treatment.

RESULTS

Sixteen randomized DBPC trials comprising 794 patients in total met the inclusion criteria. The results suggest that SLIT significantly reduces both symptom [standardized mean difference (SMD), -0.74; P=0.006] and medication scores (SMD, -0.78; P=0.02) compared with placebo. SLIT offers a better clinical response in mite sensitive asthmatics but without confirmed proof from subgroup analyses. Prolonged duration of treatment for more than 12 months brings no additive effects. Improvement in the skin prick test was also observed following immunotherapy. There was no consistent effect on forced expiratory volume in 1 s, serum levels of antigen-specific immunoglobulin G4 and immunoglobulin E in the treated group. The risk of adverse effects was relative risk 2.23 (P=0.01).

CONCLUSIONS

SLIT is safe and clinically effective in reducing symptoms and medication use for allergic asthma. Our subgroup analyses failed to identify a disproportionate benefit of SLIT in any specific group of asthmatics, but some possible trends did emerge.

Guideline on allergen-specific immunotherapy in IgE-mediated allergic diseases: S2k Guideline of the German Society for Allergology and Clinical Immunology (DGAKI), the Society for Pediatric Allergy and Environmental Medicine (GPA), the Medical Association of German Allergologists (AeDA), the Austrian Society for Allergy and Immunology (ÖGAI), the Swiss Society for Allergy and Immunology (SGAI), the German Society of Dermatology (DDG), the German Society of Oto- Rhino-Laryngology, Head and Neck Surgery (DGHNO-KHC), the German Society of Pediatrics and Adolescent Medicine (DGKJ), the Society for Pediatric Pneumology (GPP), the German Respiratory Society (DGP), the German Association of ENT Surgeons (BV-HNO), the Professional Federation of Paediatricians and Youth Doctors (BVKJ), the Federal Association of Pulmonologists (BDP) and the German Dermatologists Association (BVDD)

The present guideline (S2k) on allergen-specific immunotherapy (AIT) was established by the German, Austrian and Swiss professional associations for allergy in consensus with the scientific specialist societies and professional associations in the fields of otolaryngology, dermatology and venereology, pediatric and adolescent medicine, pneumology as well as a German patient organization (German Allergy and Asthma Association; Deutscher Allergie- und Asthmabund, DAAB) according to the criteria of the Association of the Scientific Medical Societies in Germany (Arbeitsgemeinschaft der Wissenschaftlichen Medizinischen Fachgesellschaften, AWMF). AIT is a therapy with disease-modifying effects. By administering allergen extracts, specific blocking antibodies, toler-ance-inducing cells and mediators are activated. These prevent further exacerbation of the allergen-triggered immune response, block the specific immune response and attenuate the inflammatory response in tissue. Products for SCIT or SLIT cannot be compared at present due to their heterogeneous composition, nor can allergen concentrations given by different manufacturers be compared meaningfully due to the varying methods used to measure their active ingredients. Non-modified allergens are used for SCIT in the form of aqueous or physically adsorbed (depot) extracts, as well as chemically modified allergens (allergoids) as depot extracts. Allergen extracts for SLIT are used in the form of aqueous solutions or tablets. The clinical efficacy of AIT is measured using various scores as primary and secondary study endpoints. The EMA stipulates combined symptom and medication scores as primary endpoint. A harmonization of clinical endpoints, e. g., by using the combined symptom and medication scores (CSMS) recommended by the EAACI, is desirable in the future in order to permit the comparison of results from different studies. The current CONSORT recommendations from the ARIA/GA2LEN group specify standards for the evaluation, presentation and publication of study results. According to the Therapy allergen ordinance (TAV), preparations containing common allergen sources (pollen from grasses, birch, alder, hazel, house dust mites, as well as bee and wasp venom) need a marketing authorization in Germany. During the marketing authorization process, these preparations are examined regarding quality, safety and efficacy. In the opinion of the authors, authorized allergen preparations with documented efficacy and safety, or preparations tradeable under the TAV for which efficacy and safety have already been documented in clinical trials meeting WAO or EMA standards, should be preferentially used. Individual formulations (NPP) enable the prescription of rare allergen sources (e.g., pollen from ash, mugwort or ambrosia, mold Alternaria, animal allergens) for specific immunotherapy. Mixing these allergens with TAV allergens is not permitted. Allergic rhinitis and its associated co-morbidities (e. g., bronchial asthma) generate substantial direct and indirect costs. Treatment options, in particular AIT, are therefore evaluated using cost-benefit and cost-effectiveness analyses. From a long-term perspective, AIT is considered to be significantly more cost effective in allergic rhinitis and allergic asthma than pharmacotherapy, but is heavily dependent on patient compliance. Meta-analyses provide unequivocal evidence of the efficacy of SCIT and SLIT for certain allergen sources and age groups. Data from controlled studies differ in terms of scope, quality and dosing regimens and require product-specific evaluation. Therefore, evaluating individual preparations according to clearly defined criteria is recommended. A broad transfer of the efficacy of certain preparations to all preparations administered in the same way is not endorsed. The website of the German Society for Allergology and Clinical Immunology (www.dgaki.de/leitlinien/s2k-leitlinie-sit; DGAKI: Deutsche Gesellschaft für Allergologie und klinische Immunologie) provides tables with specific information on available products for AIT in Germany, Switzerland and Austria. The tables contain the number of clinical studies per product in adults and children, the year of market authorization, underlying scoring systems, number of randomized and analyzed subjects and the method of evaluation (ITT, FAS, PP), separately given for grass pollen, birch pollen and house dust mite allergens, and the status of approval for the conduct of clinical studies with these products. Strong evidence of the efficacy of SCIT in pollen allergy-induced allergic rhinoconjunctivitis in adulthood is well-documented in numerous trials and, in childhood and adolescence, in a few trials. Efficacy in house dust mite allergy is documented by a number of controlled trials in adults and few controlled trials in children. Only a few controlled trials, independent of age, are available for mold allergy (in particular Alternaria). With regard to animal dander allergies (primarily to cat allergens), only small studies, some with methodological deficiencies are available. Only a moderate and inconsistent therapeutic effect in atopic dermatitis has been observed in the quite heterogeneous studies conducted to date. SCIT has been well investigated for individual preparations in controlled bronchial asthma as defined by the Global Initiative for Asthma (GINA) 2007 and intermittent and mild persistent asthma (GINA 2005) and it is recommended as a treatment option, in addition to allergen avoidance and pharmacotherapy, provided there is a clear causal link between respiratory symptoms and the relevant allergen. The efficacy of SLIT in grass pollen-induced allergic rhinoconjunctivitis is extensively documented in adults and children, whilst its efficacy in tree pollen allergy has only been shown in adults. New controlled trials (some with high patient numbers) on house dust mite allergy provide evidence of efficacy of SLIT in adults. Compared with allergic rhinoconjunctivitis, there are only few studies on the efficacy of SLIT in allergic asthma. In this context, newer studies show an efficacy for SLIT on asthma symptoms in the subgroup of grass pollen allergic children, adolescents and adults with asthma and efficacy in primary house dust mite allergy-induced asthma in adolescents aged from 14 years and in adults. Aspects of secondary prevention, in particular the reduction of new sensitizations and reduced asthma risk, are important rationales for choosing to initiate treatment early in childhood and adolescence. In this context, those products for which the appropriate effects have been demonstrated should be considered. SCIT or SLIT with pollen or mite allergens can be performed in patients with allergic rhinoconjunctivitis using allergen extracts that have been proven to be effective in at least one double-blind placebo-controlled (DBPC) study. At present, clinical trials are underway for the indication in asthma due to house dust mite allergy, some of the results of which have already been published, whilst others are still awaited (see the DGAKI table "Approved/potentially completed studies" via www.dgaki.de/Leitlinien/s2k-Leitlinie-sit (according to www.clinicaltrialsregister.eu)). When establishing the indication for AIT, factors that favour clinical efficacy should be taken into consideration. Differences between SCIT and SLIT are to be considered primarily in terms of contraindications. In individual cases, AIT may be justifiably indicated despite the presence of contraindications. SCIT injections and the initiation of SLIT are performed by a physician experienced in this type of treatment and who is able to administer emergency treatment in the case of an allergic reaction. Patients must be fully informed about the procedure and risks of possible adverse events, and the details of this process must be documented (see "Treatment information sheet"; available as a handout via www.dgaki.de/Leitlinien/s2k-Leitlinie-sit). Treatment should be performed according to the manufacturer's product information leaflet. In cases where AIT is to be performed or continued by a different physician to the one who established the indication, close cooperation is required in order to ensure that treatment is implemented consistently and at low risk. In general, it is recommended that SCIT and SLIT should only be performed using preparations for which adequate proof of efficacy is available from clinical trials. Treatment adherence among AIT patients is lower than assumed by physicians, irrespective of the form of administration. Clearly, adherence is of vital importance for treatment success. Improving AIT adherence is one of the most important future goals, in order to ensure efficacy of the therapy. Severe, potentially life-threatening systemic reactions during SCIT are possible, but - providing all safety measures are adhered to - these events are very rare. Most adverse events are mild to moderate and can be treated well. Dose-dependent adverse local reactions occur frequently in the mouth and throat in SLIT. Systemic reactions have been described in SLIT, but are seen far less often than with SCIT. In terms of anaphylaxis and other severe systemic reactions, SLIT has a better safety profile than SCIT. The risk and effects of adverse systemic reactions in the setting of AIT can be effectively reduced by training of personnel, adhering to safety standards and prompt use of emergency measures, including early administration of i. m. epinephrine. Details on the acute management of anaphylactic reactions can be found in the current S2 guideline on anaphylaxis issued by the AWMF (S2-AWMF-LL Registry Number 061-025). AIT is undergoing some innovative developments in many areas (e. g., allergen characterization, new administration routes, adjuvants, faster and safer dose escalation protocols), some of which are already being investigated in clinical trials. Cite this as Pfaar O, Bachert C, Bufe A, Buhl R, Ebner C, Eng P, Friedrichs F, Fuchs T, Hamelmann E, Hartwig-Bade D, Hering T, Huttegger I, Jung K, Klimek L, Kopp MV, Merk H, Rabe U, Saloga J, Schmid-Grendelmeier P, Schuster A, Schwerk N, Sitter H, Umpfenbach U, Wedi B, Wöhrl S, Worm M, Kleine-Tebbe J. Guideline on allergen-specific immunotherapy in IgE-mediated allergic diseases - S2k Guideline of the German Society for Allergology and Clinical Immunology (DGAKI), the Society for Pediatric Allergy and Environmental Medicine (GPA), the Medical Association of German Allergologists (AeDA), the Austrian Society for Allergy and Immunology (ÖGAI), the Swiss Society for Allergy and Immunology (SGAI), the German Society of Dermatology (DDG), the German Society of Oto-Rhino-Laryngology, Head and Neck Surgery (DGHNO-KHC), the German Society of Pediatrics and Adolescent Medicine (DGKJ), the Society for Pediatric Pneumology (GPP), the German Respiratory Society (DGP), the German Association of ENT Surgeons (BV-HNO), the Professional Federation of Paediatricians and Youth Doctors (BVKJ), the Federal Association of Pulmonologists (BDP) and the German Dermatologists Association (BVDD). Allergo J Int 2014;23:282-319.

The placebo effect in allergen-specific immunotherapy trials

BACKGROUND

Double-blind, placebo-controlled (DBPC) trials are the gold standard for demonstrating clinical efficacy and tolerability. The placebo effect, although an important feature in placebo-controlled studies, has never been systematically investigated in allergen-specific immunotherapy (SIT) studies. This study was performed to examine the placebo response in SIT trials that employed a baseline observational period and two treatment years using a symptom-medication-score (SMS) as the primary endpoint.

METHODS

The placebo effect was evaluated in six DBPC SIT studies (five studies using subcutaneous SIT (SCIT) and one sublingual (SLIT)), two grass, two birch and two house dust mite (HDM) SIT, including a total of 472 adult patients treated with a placebo. The results were reported as changes from baseline of the SMS area under the curve after two years of perennial placebo therapy during the respective evaluation periods. Pollen counts and IgG4 levels were additionally analysed.

RESULTS

Subcutaneously treated placebo patients displayed a marked decrease in the SMS. The mean placebo effect in the SCIT trials with comparable allergen exposure was up to 41% in the second treatment year and, in contrast, reached only 1% in the SLIT trial. Allergen exposure had an inverse influence on the placebo effect. No changes from baseline in allergen specific IgG4 antibodies were observed in the placebo-treated patients.

CONCLUSIONS

SIT studies display a significant placebo effect, mainly observed in subcutaneous immunotherapy, with high variability depending on the route of application and allergen exposure. Our findings indicate the differential role of the placebo effect in SIT efficacy depending on the route of administration and pollen exposure.

Sublingual immunotherapy in preschool children: an update

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

An evidence-based analysis of house dust mite allergen immunotherapy: a call for more rigorous clinical studies

BACKGROUND

According to meta-analyses and reviews, subcutaneous allergen immunotherapy (SCIT) and sublingual allergen immunotherapy (SLIT) are beneficial in patients with allergic rhinitis (AR) and allergic asthma (AA) induced by house dust mites (HDMs). However, the reported effect sizes have varied greatly from one study to another.

OBJECTIVE

We sought to perform an evidence-based medicine assessment of commercially available SCIT and SLIT formulations in patients with HDM-induced AA and HDM-induced AR.

METHODS

We searched for double-blind, placebo-controlled randomized clinical trials and analyzed study designs, doses, regimens, patient-reported outcomes, safety reporting, and compliance.

RESULTS

Forty-four studies met our inclusion criteria. Some studies tested both SLIT and SCIT or scored both AA and AR outcomes; therefore we reviewed 35 treatment arms in patients with AA (20 for SCIT and 15 for SLIT) and 23 treatment arms in patients with AR (7 for SCIT and 16 for SLIT). The treatment duration ranged from 6 weeks to 3 years. For SCIT, the dose of Der p 1 major allergen (when reported) ranged from 7 to 30 μg for maintenance doses and 60 to 420 μg for cumulative doses. For SLIT, the doses of Der p 1 (when reported) were 0.8 to 70 μg for maintenance doses and 60 to 23,695 μg for cumulative doses. Safety data were often absent or poorly reported. A statistically significant active versus placebo symptom score was observed more frequently for SCIT than for SLIT.

CONCLUSION

There is no consensus on basic treatment parameters (eg, dose and duration) in HDM SCIT and SLIT. There is an urgent need for rigorous, long-term, double-blind, placebo-controlled randomized clinical trials with an efficacy criterion that reflects the particular features of HDM-induced allergic disease.

Allergen immunotherapy for house dust mite: clinical efficacy and immunological mechanisms in allergic rhinitis and asthma

INTRODUCTION

There is an increasing prevalence of atopic diseases such as allergic rhinitis and asthma with house dust mite (HDM) being the common allergen that is highly associated with allergic rhinitis and asthma. Allergen avoidance and pharmacotherapy are part of treatment but it has proved difficult to change the course of HDM-related allergic diseases. Allergen immunotherapy (AIT) has been in use for the past century and has been shown to be effective in the treatment of allergic respiratory disease.

AREAS COVERED

This review exclusively focuses on HDM-AIT and discusses the differences in clinical efficacy and safety, long-term effect after discontinuation and immunological changes observed in both HDM-subcutaneous immunotherapy (SCIT) and HDM-sublingual immunotherapy (SLIT) in the treatment of allergic rhinitis and asthma in both pediatric and adult populations.

EXPERT OPINION

The majority of studies involved small numbers of patients, variable doses of major allergens and are of variable quality. There is good evidence for HDM-SCIT efficacy and its long-term effect in adults and children, whereas at the present time, evidence for HDM-SLIT is unconvincing, particularly in children. In carefully selected patients, HDM-SCIT is effective and safe. More definitive trials are needed before HDM-SLIT can be recommended in routine practice for rhinitis and/or asthma.

Fast onset of action of sublingual immunotherapy in house dust mite-induced allergic rhinitis: a multicenter, randomized, double-blind, placebo-controlled trial

OBJECTIVES/HYPOTHESIS

To investigate how quickly an allergic rhinitis (AR) patients' symptoms will improve with sublingual immunotherapy (SLIT).

STUDY DESIGN

Double-blind placebo study.

METHODS

This is a multicenter, randomized, double-blind, placebo-controlled study of SLIT used to treat house dust mite-induced AR. A total of 120 AR patients, aged 4 to 60 years, were treated for 6 months and randomized into two groups: 1) SLIT with Dermatophagoides pteronyssinus (D.p.) and Dermatophagoides farina (D.f.) extract (n = 60) ; and 2) matched placebo controls (n = 60). Symptom, medications received, and a visual analog scale score were recorded during the whole study. Serum-specific IgE and IgG4 to D. p. and D. f. were assessed before and after the treatment.

RESULTS

Eighty-five patients (70.8%) completed the study. Twelve patients (20%) chose to withdraw from the SLIT group, but none because of serious adverse effects. The total symptom and visual analog scores VAS in the SLIT group decreased significantly when compared to the placebo controls (P <0.05) after week 14, as well as for the significant (P <0.05) improvement of all individual AR symptoms in the SLIT group (e.g., sneezing, nasal discharge, itching, and nasal obstruction) after week 22. There was a significant (P <0.05) increase of IgG4 to both D.f. and D.p. in the SLIT, but not in the placebo group after treatment.

CONCLUSION

SLIT with a mixture of D.f. and D.p. extract is an effective and safe treatment for patients with house dust mite-induced AR. Its onset of action can be observed as early as 14 weeks after treatment.

Sublingual immunotherapy

Sublingual immunotherapy (SLIT) has been shown to be safe and efficacious in treating allergic rhinitis. It has been used in Europe for more than 20 years, and interest in the United States is increasing. SLIT has been shown to elicit immunologic changes similar to subcutaneous injection immunotherapy. SLIT may prevent new sensitizations, improve asthma control, and decrease asthma development in allergic individuals. Although differences in antigen quantification and standardization make European dosing schemes difficult to translate in the United States, several new studies suggest the range for effective dosing. Further studies will help clarify optimal dosing.

Sublingual immunotherapy for treating allergic conjunctivitis

BACKGROUND

Allergic ocular symptoms, although frequently trivialised, are common and represent an important comorbidity of allergic rhinitis. Sublingual Immunotherapy (SLIT) is an effective and well-tolerated treatment for allergic rhinitis, but its effects on symptoms of ocular allergy have not been well established.

OBJECTIVES

To evaluate the efficacy of SLIT compared with placebo for reductions in ocular symptoms, topical ocular medication requirements and conjunctival immediate allergen sensitivity.

SEARCH STRATEGY

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 1), MEDLINE (January 1950 to January 2011), EMBASE (January 1980 to January 2011), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to January 2011), Web of Science (January 1970 to January 2011), Biosis Previews, (January 1979 to January 2011), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) (January 2011), ClinicalTrials.gov (www.clinicaltrials.gov) (January 2011), the Australian New Zealand Clinical Trials Registry (ANZCTR) (www.actr.org.au) (July 2010), SCOPUS (November 2008) and the UK Clinical Trials Gateway (January 2010). There were no language or date restrictions in the search for trials. All electronic databases except for SCOPUS, the UK Clinical Trials Gateway and ANZCTR were last searched on 19 January 2011.

SELECTION CRITERIA

Randomised controlled trials (RCTs), double-masked and placebo controlled, which evaluated the efficacy of SLIT in patients with symptoms of allergic rhinoconjunctivitis (ARC) or allergic conjunctivitis (AC).

DATA COLLECTION AND ANALYSIS

The primary outcome was the total ocular symptom scores. Secondary endpoints included individual ocular symptom scores (such as itchy eyes, red eyes, watery eyes, swollen eyes), ocular medication scores (eye drops) and conjunctival immediate allergen sensitivity (CIAS). Data were analysed and reported as standardised mean differences (SMDs) using Review Manager software.

MAIN RESULTS

Forty-two trials (n = 3958 total participants; n= 2011 SLIT and n = 1947 placebo) had available data to evaluate the efficacy of SLIT on AC and were included in the meta-analyses. Heterogeneity among studies (I(2) statistic) was around 50% or below for all endpoints. Sublingual immunotherapy induced a significant reduction in both total ocular symptom scores (SMD -0.41; 95% confidence interval (CI) -0.53 to -0.28; P < 0.00001; I(2) = 59%) and individual ocular symptom scores for red eyes (SMD -0.33; 95% CI -0.45 to -0.22; P < 0.00001; I(2) = 27%), itchy eyes (SMD -0.31; 95% CI -0.42 to -0.20; P < 0.00001; I(2) = 46%) and watery eyes (SMD -0.23; 95% CI -0.34 to -0.11; P < 0.0001; I(2) = 42%) compared to placebo. Those participants having active treatment showed an increase in the threshold dose for the conjunctival allergen provocation test (SMD 0.35; 95% CI 0.00 to 0.69; P = 0.05; I(2) = 43%). No significant reduction was observed in ocular eye drops use (SMD -0.10; 95% CI -0.22 to 0.03; P = 0.13; I(2) = 34%).

AUTHORS' CONCLUSIONS

Overall, SLIT is moderately effective in reducing total and individual ocular symptom scores in participants with ARC and AC. There were however some concerns about the overall quality of the evidence-base, this relating to inadequate descriptions of allocation concealment in some studies, statistical heterogeneity and the possibility of publication bias. There is a need for further large rigorously designed studies that study long-term effectiveness after discontinuation of treatment and establish the cost-effectiveness of SLIT.

Systematic reviews of sublingual immunotherapy (SLIT)

Allergic rhinitis is common worldwide, with significant morbidity and impact on quality of life. In patients who don't respond adequately to anti-allergic drugs. Subcutaneous allergen immunotherapy is effective although requires specialist administration. Sublingual immunotherapy may represent an effective and safer alternative. This Cochrane systematic review is an update of one published in 2003. We searched Cochrane ENT Group Trials Register, Central, PubMed, EMBASE, CINAHL, Web of Science, Biosis Previews, Cambridge Scientific Abstarcts, mRCT and additional sources. We included randomised, double-blind, placebo- controlled trials of sublingual immunotherapy in adults and children. Two authors selected studies and assessed them for quality. Data were put into RevMan 5.0 for a statistical analysis. We used standardised mean difference (SMD), with a random effect model to combine data. Sixty studies were included, with 49 suitable for meta-analysis. We found significant reductions in symptoms (SMD -0.49; 95%CI (-0.64 to -0.34, P < 0.00001)) and medication requirements (SMD -0.32; 95%CI (-0.43 to -0.21, P < 0.00001)) compared with placebo. None of the trials reported severe systemic reactions, anaphylaxis or use of Adrenaline. This updated review reinforces the conclusion of the original 2003 Cochrane Review that sublingual immunotherapy is effective for allergic rhinitis and appears a safe route of administration.

Clinical and immunologic effects of sublingual immunotherapy on patients with allergic rhinitis to house-dust mites: 1-year follow-up results

BACKGROUND

There have been no data on sublingual immunotherapy (SLIT) in Asian patients with allergic rhinitis (AR) sensitized to house-dust mites (HDMs). This study aimed to investigate the efficacy and immunologic change after 12 months of SLIT in Korean patients.

METHODS

Fifty-eight patients, who had AR caused by Dermatophagoides pteronyssinus and Dermatophagoides farinae and who completed 12 months of SLIT were included. Symptom scores were evaluated before and after 12 months of SLIT, and medication scores were assessed throughout the study. Peripheral blood eosinophil counts, eosinophil cationic protein (ECP), total IgE, and specific IgE were also evaluated.

RESULTS

All of the symptoms of AR were significantly improved with reduced medication scores. In addition, there were significant decrements in peripheral blood eosinophil counts and ECP (p = 0.025 and p = 0.048, respectively). Specific IgE for D. farinae slightly increased (p = 0.019), whereas specific IgE for D. pteronyssinus and total IgE did not change significantly. Thirty-six (62%) of 58 patients were in the effective response group. Although not statistically significant, findings in the study showed that the effective response group had a tendency to have higher ECP levels before SLIT than the ineffective response group (p = 0.056).

CONCLUSION

SLIT improved the symptoms and medication scores in Korean patients with AR from HDM. Laboratory parameters including eosinophil counts, ECP, and specific IgE for D. farinae seemed to be modified after 1-year SLIT. A high ECP level may be a useful parameter to predict the effectiveness of SLIT and select the patient for the treatment.

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

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

Sublingual immunotherapy for allergic rhinitis

BACKGROUND

This is an update of a Cochrane Review first published in The Cochrane Library in Issue 2, 2003.Allergic rhinitis is a common condition which can significantly impair quality of life. Immunotherapy by injection can significantly reduce symptoms and medication use but its use is limited by the possibility of severe systemic adverse reactions. Immunotherapy by the sublingual route is therefore of considerable interest.

OBJECTIVES

To evaluate the efficacy and safety of sublingual immunotherapy for allergic rhinitis in adults and children.

SEARCH STRATEGY

We searched the Cochrane ENT Group Trials Register; CENTRAL (2010, Issue 3); PubMed; EMBASE; CINAHL; Web of Science; BIOSIS Previews; Cambridge Scientific Abstracts; mRCT and additional sources for published and unpublished trials. The date of the most recent search was 14 August 2009.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled trials of sublingual immunotherapy in adults or children. Primary outcome measures were symptom and medication scores. We also collected adverse event data.

DATA COLLECTION AND ANALYSIS

Two independent authors selected studies and assessed risk of bias. One author extracted data which was rechecked by two other authors. We used the standardised mean difference (SMD) with a random-effects model to combine data.

MAIN RESULTS

We included a total of 60 randomised controlled trials in the review. Forty-nine were suitable for pooling in meta-analyses (2333 SLIT, 2256 placebo participants). Overall, we found a significant reduction in symptoms (SMD -0.49; 95% confidence interval (CI) -0.64 to -0.34, P < 0.00001) and medication requirements (SMD -0.32; 95% CI -0.43 to -0.21, P < 0.00001) in participants receiving sublingual immunotherapy compared to placebo. None of the trials included in this review reported severe systemic reactions or anaphylaxis, and none of the systemic reactions reported required the use of adrenaline.

AUTHORS' CONCLUSIONS

This updated review reinforces the conclusion of the original 2003 Cochrane Review that sublingual immunotherapy is effective for allergic rhinitis and has been proven to be a safe route of administration.

Treatment of congestion in upper respiratory diseases

Congestion, as a symptom of upper respiratory tract diseases including seasonal and perennial allergic rhinitis, acute and chronic rhinosinusitis, and nasal polyposis, is principally caused by mucosal inflammation. Though effective pharmacotherapy options exist, no agent is universally efficacious; therapeutic decisions must account for individual patient preferences. Oral H₁-antihistamines, though effective for the common symptoms of allergic rhinitis, have modest decongestant action, as do leukotriene receptor antagonists. Intranasal antihistamines appear to improve congestion better than oral forms. Topical decongestants reduce congestion associated with allergic rhinitis, but local adverse effects make them unsuitable for long-term use. Oral decongestants show some efficacy against congestion in allergic rhinitis and the common cold, and can be combined with oral antihistamines. Intranasal corticosteroids have broad anti-inflammatory activities, are the most potent long-term pharmacologic treatment of congestion associated with allergic rhinitis, and show some congestion relief in rhinosinusitis and nasal polyposis. Immunotherapy and surgery may be used in some cases refractory to pharmacotherapy. Steps in congestion management include (1) diagnosis of the cause(s), (2) patient education and monitoring, (3) avoidance of environmental triggers where possible, (4) pharmacotherapy, and (5) immunotherapy (for patients with allergic rhinitis) or surgery for patients whose condition is otherwise uncontrolled.

Development of an allergen extract for sublingual immunotherapy--evaluation of Staloral

BACKGROUND

Specific immunotherapy (IT) is an effective treatment for rhinitis and asthma caused by aeroallergens sensitization. Sublingual IT (SLIT) was introduced to solve the problem of systemic reactions to subcutaneous IT (SCIT) and developed to represent an actual treatment option. It is now generally accepted that allergen doses much higher than those administered by SCIT must be used to achieve clinical efficacy on allergic symptoms.

OBJECTIVE

To evaluate the characteristics of Staloral, an allergen extract produced by Stallergenes (Antony, France) in terms of practical administration, efficacy, safety and mechanism of action.

METHODS

Data were obtained from 20 double-blind, placebo-controlled studies using Staloral in patients sensitized to pollens and house-dust mites, and also from open studies concerning practical administration and the mechanism of action.

RESULTS/CONCLUSION

Efficacy and safety of Staloral, as demonstrated by the revision of the studies, which used doses up to 1125 times those administered with SCIT, are very satisfactory and confer to this allergen extract optimal characteristics for treating patients with seasonal allergies due to pollens or with perennial symptoms induced by dust mites. The main mechanism of action is the interaction with dendritic cells of the oral mucosa and the subsequent tolerance induced in T cells.

The CONSORT statement checklist in allergen-specific immunotherapy: a GA2LEN paper

The methodology of randomized clinical trials is essential for the critical assessment and registration of therapeutic interventions. The CONSORT (Consolidated Standards of Reporting Trials) statement was developed to alleviate the problems arising from the inadequate reporting of randomized controlled trials. The present article reflects on the items that we believe should be included in the CONSORT checklist in the context of conducting and reporting trials in allergen-specific immunotherapy. Only randomized, blinded (in particular blinding of patients, health care providers, and outcome assessors), placebo-controlled Phase III studies in this article. Our analysis focuses on the definition of patients' inclusion and exclusion criteria, allergen standardization, primary, secondary and exploratory outcomes, reporting of adverse events and analysis.

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

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

The efficacy of sublingual immunotherapy for house dust mites respiratory allergy: results of a GA2LEN meta-analysis

Recent meta-analyses documented the efficacy and safety of sublingual immunotherapy (SLIT) in patients with allergic rhinitis (AR) and asthma (AA). Although SLIT appeared globally effective, the sub-analyses for single allergens provided uncertain results. This study is aimed to investigate the efficacy of SLIT with house dust mite (HDM) extracts in AR and AA through an updated reassessment of randomized controlled trials. Electronic databases were searched up to March 31, 2008, for randomized DBPC trials, assessing the efficacy of SLIT in AR and AA due to HDM sensitization. Outcomes were symptom scores and rescue medications use. For AR, eight studies fulfilled the selection criteria. A significant reduction in symptoms of AR (SMD -0.95; CI 95%-1.77 to -0.14 P = 0.02) was found in 194 patients (adults and children) receiving SLIT compared to 188 receiving placebo. For AA, with nine studies, similar results were found for symptoms (SMD -0.95; CI 95%-1.74 to -0.15 P = 0.02) in 243 patients (adults and children) receiving SLIT compared to 209 receiving placebo. A reduction in rescue medication use was found for AR (SMD -1.88; CI 95%-3.65 to -0.12 P = 0.04) in 89 patients, and AA (SMD -1.48; CI 95%-2.70 to -0.26 P = 0.02) in 202 patients. A relevant inter-study heterogeneity was detected. Promising evidence of efficacy for SLIT, using mite extract in allergic patients suffering from AR and AA, are herein shown. These findings suggest that more data are needed, derived from large-population-based high quality studies, and corroborated by objective outcomes, mainly for AA.

Mechanisms of sublingual immunotherapy

Allergen-specific sublingual immunotherapy is now recognized to be an efficacious and well-tolerated treatment for allergic rhinitis. Emerging treatment strategies are also aimed at the primary treatment of allergic asthma, particularly allergy to house dust mites. Knowledge of the exact mechanisms of action of sublingual immunotherapy is at a basic level, although there appear to be similarities to the immunological changes seen in subcutaneous immunotherapy. An improved understanding should allow the development of more effective treatment programs and widen the potential use of this form of immunotherapy. This review discusses the possible mechanism of action of sublingual immunotherapy, including data from animal and clinical studies, while comparing this with the current understanding of subcutaneous immunotherapy.

Comparison of the long-term efficacy of subcutaneous and sublingual immunotherapies in perennial rhinitis

BACKGROUND

Both sublingual and subcutaneous immunotherapies have a documented clinical efficacy, but only a few comparative studies have been performed.

OBJECTIVES

To evaluate and compare the long-term efficacies of subcutaneous and sublingual immunotherapy.

METHODS

One hundred and ninety-three patients with house dust mite allergies, out of an original total of 230, were treated with subcutaneous and sublingual house dust mite-specific immunotherapies for 3 years and also observed for 3 years after discontinuation of the treatment. The patients were randomized into 2 groups: the sublingual group (97 patients) and the subcutaneous group (96 patients). The therapy's success was evaluated using the symptom score, skin prick test results, and the nasal allergen challenge score. The patients were evaluated at the beginning of the study, at the end of years 1, 2, and 3, and also at the end of the 1st and 3rd years after discontinuation of the specific immunotherapy treatment.

RESULTS

Immunotherapy induced a significant improvement during the treatment and the follow-up period. We found a greater improvement in the subcutaneous group compared to the sublingual group when we looked at the comparative results of the total 6 years.

CONCLUSION

We suggest subcutaneous immunotherapy for patients with perennial allergic rhinitis due to the better results that were obtained during our study period. Nevertheless, sublingual immunotherapy is now accepted by WHO as a valid alternative to the subcutaneous route and should be used in all patients who require immunotherapy and do not accept the subcutaneous route of allergen administration.

Immunotherapy: clinical trials--optimal trial and clinical outcomes

PURPOSE OF REVIEW

The methodology of randomized clinical trials is essential to assess and register treatment interventions. Although specific immunotherapy was introduced a century ago, very few trials meet the criteria for pivotal studies. The paper reviews the methods which should be used to investigate specific immunotherapy.

RECENT FINDINGS

Large pivotal trials on specific immunotherapy were published within the last year and made sublingual immunotherapy an accepted treatment in Europe. Moreover, a study proposed the guidelines for conducting trials on immunotherapy. Phase I studies were also published on sublingual immunotherapy. A large trial on subcutaneous immunotherapy confirmed its efficacy, but showed that this form of treatment is associated with side effects.

SUMMARY

The clinical efficacy of subcutaneous and sublingual immunotherapy with pollen and mites is well established for both rhinitis and asthma, but the methodology of many specific immunotherapy trials was found to be insufficient until recent large pivotal studies. The present paper reviews the requirements for conducting trials in allergen-specific immunotherapy including allergen standardization, patient inclusion and exclusion criteria, phase I trials to assess safety, dose-ranging studies, and pivotal trials. These need to be randomized, parallel group, placebo-controlled designs. The number of patients should be sufficient. Primary and secondary outcome measures are listed. Trials for asthma need specific requirements. In all trials, safety should be carefully monitored. Studies in children are required.

Long-term efficacy of sublingual immunotherapy in patients with perennial rhinitis

BACKGROUND

Sublingual immunotherapy has a documented clinical efficacy, but only a few long-term studies have been performed in people with perennial rhinitis.

OBJECTIVES

The purpose of this study was to evaluate the long-term efficacy of sublingual immunotherapy.

METHODS

One hundred thirty-seven patients with allergies to house dust mites were treated with sublingual house dust-mite-specific immunotherapy for 2 or 3 years and were also observed for 3 years after discontinuation of the treatment. The patients were divided into 2 groups: group A (67 patients) received active treatment for 2 years and then 1 year for placebo, and group B (70 patients) received active treatment for 3 years. The success of the treatment was evaluated with the symptom score, skin prick test results, and the nasal allergen challenge score.

RESULTS

According to our study results, we found a greater improvement in the 3 years of sublingual immunotherapy compared with the 2 years of sublingual immunotherapy when we looked at the comparative results of the total 6 years.

CONCLUSION

We suggest 3 years of sublingual immunotherapy for patients with perennial allergic rhinitis who require immunotherapy and do not accept the subcutaneous route of allergen administration.

Allergic rhinitis and its impact on asthma update: allergen immunotherapy

The Allergic Rhinitis and its Impact on Asthma document was first published in 2001. Since then, new data on specific immunotherapy have appeared. This review is intended as an update to the original document. MedLine (2001 to June 2006) was searched with appropriate key words, and panelists were asked to identify further relevant articles. Randomized controlled trials were considered for the evaluation of efficacy. For the evaluation of safety and additional effects, studies with lower grades of evidence were included. The clinical efficacy of injection immunotherapy in rhinitis and asthma was confirmed, as well as the safety, provided that recommendations are followed. Studies have demonstrated the long-term efficacy and the preventive effect of immunotherapy in reducing the onset of new sensitizations. One randomized open trial demonstrated that in children with allergic rhinitis, injection immunotherapy may reduce the risk of developing asthma. There is strong evidence that sublingual immunotherapy is effective in allergic rhinitis in adults. Recent meta-analyses demonstrated its efficacy in allergic rhinitis in children and in asthma, although more definitive trials are required. Current data indicate that sublingual immunotherapy is safe and the rate of adverse reactions is not greater below 5 years of age. One randomized open trial showed that in children with allergic rhinitis, sublingual immunotherapy reduced the onset of asthma. Further studies are needed to identify the optimal maintenance dose and to elucidate the mechanism of action. Novel approaches for immunotherapy are currently under evaluation, including the use of adjuvants, peptides, and DNA-conjugated and recombinant allergens.

Sublingual immunotherapy: update 2006

PURPOSE OF REVIEW

Sublingual immunotherapy is currently accepted as a viable therapeutic option, and is widely used in many European countries. In the past 2 years, new data concerning clinical, immunological and practical aspects of sublingual immunotherapy have been published, and many critical points have been addressed.

RECENT FINDINGS

In addition to the new data on clinical efficacy, the most recent studies have shown that, similar to the injection route, sublingual immunotherapy can also prevent the onset of new sensitizations and the onset of asthma. Moreover, several postmarketing surveys have confirmed the satisfactory safety profile, even in very young children, and compliance has been measured. The good safety profile has also suggested the possibility of using sublingual immunotherapy without the updosing phase. Finally, the mechanisms of action have been systematically investigated and the biodistribution of sublingual allergens has been further clarified.

SUMMARY

More new data on sublingual immunotherapy are rapidly appearing in the international literature. These data consistently confirm the value of this treatment and show that sublingual immunotherapy is a viable and useful form of immunotherapy.

Assessment of sublingual immunotherapy efficacy in children with house dust mite-induced allergic asthma optimally controlled by pharmacologic treatment and mite-avoidance measures

Although several studies have demonstrated the efficacy of subcutaneous immunotherapy in allergic asthma, few have shown the same benefit using sublingual immunotherapy (SLIT) in asthmatic patients. This study was conducted to assess the efficacy of house dust mite (HDM) SLIT in addition to allergen avoidance and standard pharmacologic treatment. A double-blind, placebo-controlled trial was performed in 111 children (aged 5-15 yr) with HDM-induced mild-to-moderate asthma. After a 4-week baseline phase, patients were randomly assigned to receive SLIT with tablets of HDM extract (n = 55) or placebo (n = 56) for 18 months. Pharmacologic treatment was adjusted every 3 months following a step-down approach. Asthma symptom scores, reduction in use of inhaled corticosteroids and inhaled beta(2)-agonists, rhinitis symptoms, lung function tests, skin sensitivity to HDM, dust mite-specific immunoglobulin (Ig) E and IgG(4), and quality of life (QoL) were assessed during the study. After 18 months of treatment, diurnal and nocturnal asthma symptoms scores did not show significant differences between SLIT and placebo groups. Inhaled corticosteroids and inhaled beta(2)-agonists use was reduced in both groups without significant differences between groups. There were no significant differences in lung function (forced expiratory volume in 1 s and peak flow rate variations) between groups. Rhinitis symptom score decreased in both groups, with no difference between the two groups. The severity dimension of QoL was significantly improved in the SLIT group (age 6-12 yr). SLIT induced a significant reduction of skin sensitivity to HDM (p < 0.01) and a significant increase in HDM-specific IgE and IgG(4) antibodies (p < 0.001) in the SLIT group compared with the placebo group. SLIT was well tolerated with mild/moderate local adverse events. No severe systemic reactions were reported. This study indicates that, when mild-moderate asthmatic children are optimally controlled by pharmacologic treatment and HDM avoidance, SLIT does not provide additional benefit, despite a significant reduction in allergic response to HDM. Under such conditions, only a complete, but ethically unfeasible, discontinuation of inhaled corticosteroid would have demonstrated a possible benefit of SLIT.