Noninjection routes for immunotherapy

Cell-penetrating albumin enhances the sublingual delivery of antigens through macropinocytosis

Innovations in oral immunotherapy have greatly advanced the therapeutic control of allergies. However, these therapeutic effects suffer from the fact that the amount of antigen delivered to antigen-presenting cells is limited given the formulations that are currently available. We recently designed a cell-penetrating albumin and found that this modified albumin enters cells via the induction of macropinocytosis. Herein, we report on a novel system for delivering antigens based on cell-penetrating albumin-inducible macropinocytosis that allows larger amounts of antigens to be delivered to antigen-presenting cells. A treatment with cell-penetrating albumin significantly increased the permeability of ovalbumin (45 kDa) or dextran (2000 kDa) on monolayers derived from human oral squamous carcinoma cells. Flow cytometric analyses showed that the cell-penetrating albumin treatment resulted in a significant elevation in the amount of dextran that was delivered to two types of antigen-presenting cells. Finally, mice that had been sensitized by Japanese cedar pollen extract (JCPE) and cell-penetrating albumin showed a decline in the frequency of nose-rubbing against a subsequent intranasal administration of JCPE. These findings suggest that the sublingual administration of cell-penetrating albumin efficiently delivers antigens to antigen-presenting cells via the induction of macropinocytosis, resulting in an enhancement in the therapeutic effect of sublingual immunotherapy.

Alternatives to Subcutaneous Immunotherapy for Allergic Rhinitis

Allergic rhinitis (AR) is an important public health issue worldwide due to its increasing prevalence and impact on quality of life, school performance, and work productivity. Subcutaneous immunotherapy (SCIT) is used to treat AR and involves repeated injections of allergen extracts. SCIT is used for cases of severe AR with symptoms that are not adequately controlled by medication, when the side effects of medication limit treatment options, or where the aim is to cure rather than symptomatically treat. Although SCIT is effective, it is not necessarily curative. Furthermore, there is also a low but present risk of systemic allergic reactions, with systemic side effects occurring in less than 0–1% of treated patients. Sublingual immunotherapy (SLIT) has emerged as an effective and safe alternative to SCIT. SCIT and SLIT are the only immunotherapies currently available for AR. In addition to sublingual administration as an alternative to SCIT, other routes of antigen administration have been attempted with the goal of increasing safety while maintaining efficacy. This review discusses the efficacies of SCIT and SLIT, their mechanisms, the utility of intralymphatic immunotherapy (ILIT) as an alternative route of antigen administration, and the potential for immunotherapy using other routes of antigen administration.

Recent Advances in Allergen-Specific Immunotherapy in Humans: A Systematic Review

Allergen-specific immunotherapy (AIT) is presumed to modulate the natural course of allergic disease by inducing immune tolerance. However, conventional AITs, such as subcutaneous immunotherapy and sublingual immunotherapy, require long treatment durations and often provoke local or systemic hypersensitivity reactions. Therefore, only <5% of allergy patients receive AIT as second-line therapy. Novel administration routes, such as intralymphatic, intradermal and epicutaneous immunotherapies, and synthetic recombinant allergen preparations have been evaluated to overcome these limitations. We will review the updated views of diverse AIT methods, and discuss the limitations and opportunities of the AITs for the treatment of allergic diseases in humans.

Allergen immunotherapy: The growing role of observational and randomized trial "Real-World Evidence"

BACKGROUND

Although there is a considerable body of knowledge about allergen immunotherapy (AIT), there is a lack of data on the reliability of real-world evidence (RWE) in AIT, and consequently, a lack of information on how AIT effectively works in real life.

METHODS

To address the current unmet need for an appraisal of the quality of RWE in AIT, the European Academy of Allergy and Clinical Immunology Methodology Committee recently initiated a systematic review of observational studies of AIT, which will use the RELEVANT tool and the Grading of Recommendations Assessment, Development and Evaluation approach (GRADE) to rate the quality of the evidence base as a whole. The next step will be to develop a broadly applicable, pragmatic "real-world" database using systematic data collection. Based on the current RWE base, and perspectives and recommendations of authorities and scientific societies, a hierarchy of RWE in AIT is proposed, which places pragmatic trials and registry data at the positions of highest level of evidence.

KEY RESULTS

There is a need to establish more AIT registries that collect data in a cohesive way, using standardized protocols.

CONCLUSIONS

This will provide an essential source of real-world data that can be easily shared, promoting evidence-based research and quality improvement in study design and clinical decision-making.

Next-Generation Allergen-Specific Immunotherapy for Japanese Cedar Pollinosis Using Molecular Approaches

Japanese cedar (JC) pollinosis is the most major IgE-mediated type I allergic disease in Japan. Allergen-specific immunotherapy is the only curative treatment for allergic diseases. Subcutaneous immunotherapy and sublingual immunotherapy have been introduced in Japan for JC pollinosis, but do not avoid some adverse side effects, because the natural allergens used as tolerogens cross-link with specific IgE types on mast cells and basophils. To make immunotherapy for JC pollinosis safer, more effective and convenient, rice-based oral allergy vaccines using hybrid peptides composed of multiple T-cell epitopes or recombinant deconstructed hypoallergenic derivatives derived from major allergens — Cry j 1 and Cry j 2 — have been developed and their efficacy and safety evaluated by oral administration of transgenic rice seeds. Furthermore, recombinant modified JC allergens conjugated with various immunomodulatory molecules and DNA-based vaccines have been created and their efficacy assessed.

Microparticles and Nanoparticles from Plants-The Benefits of Bioencapsulation

The efficacy of drugs and vaccines depends on their stability and ability to interact with their targets in vivo. Many drugs benefit from encapsulation, which protects them from harsh conditions and allows targeted delivery and controlled release. Although many encapsulation methods are inexpensive, such as the formulation of tablets for oral delivery, others require complex procedures that add significantly to production costs and require low-temperature transport and storage, making them inaccessible in developing countries. In this review we consider the benefits of encapsulation technologies based on plants. Plant-derived biopolymers such as starch and the maize storage protein zein are already used as protective coatings, but plant cells used as production host provide natural in vivo bioencapsulation that survives passage through the stomach and releases drugs in the intestine, due to the presence of microbes that can digest the cell wall. Proteins can also be encapsulated in subcellular compartments such as protein bodies, which ensure stability and activity while often conferring additional immunomodulatory effects. Finally, we consider the incorporation of drugs and vaccines into plant-derived nanoparticles assembled from the components of viruses. These are extremely versatile, allowing the display of epitopes and targeting peptides as well as carrying cargoes of drugs and imaging molecules.

Sublingual dendritic cells targeting by aptamer: Possible approach for improvement of sublingual immunotherapy efficacy

The efficacy improvement of current sublingual immunotherapy (SLIT) for preventing and treating respiratory airway allergic diseases is the main purpose of many investigations. In this study, we aimed to assess whether ovalbumin (Ova) encapsulated poly (lactic-co-glycolic) acid nanoparticles (PLGA NPs) decorated with dendritic cells (DCs)-specific aptamer could be applied for this purpose.The nanoparticles containing Ova were synthesized by emulsion/solvent evaporation method and attached to DCs-specific aptamer. Ova-sensitized BALB/c mice have been treated in five ways: subcutaneously with free Ova (SCIT), sublingually either with free Ova, Ova-PLGA NPs (two doses), Apt-Ova-PLGA NPs (two doses) and placebo/control Apt-Ova-PLGA NPs. For assessment of immunologic responses, IL-4, IFN-γ, IL-17, IL10, and TGF-β and IgE antibody levels were measured by ELISA and T cell proliferation were evaluated by MTT. In addition, lung and nasal histological examinations, NALF cells counting were carried out. Results declared that the lowest IgE and IL- 4 levels were observed in Apt-Ova-PLGA NPs (both doses). In the other hands, Apt-Ova-PLGA NPs (high dose) showed the highest increase of IFN- γ and TGF- β, decrease of IL-17 levels, total cell count and T-cell proliferation. IL-10 levels showed more decrease in SCIT, Apt-Ova-PLGA NPs (high dose) and Ova-PLGA NPs (high dose) than other groups. Histopathological examinations also confirmed in vitro results. Our findings suggest SLIT with this functionalized delivery system could be a promising approach for promoting the SLIT efficiency by decreasing the required allergen doses through specific delivery of allergen to sublingual DCs and enhancing the suppression of allergic responses.

[Developmental history of sublingual immunotherapy]

Allergen immunotherapy is the only curative treatment for IgE-mediated allergic diseases in contrast to symptomatic treatment such as anti-histamine agents. Subcutaneous immunotherapy (SCIT) has been introduced in Japan for treatment of allergic rhinitis and/or asthma caused by pollens and/or house dust mites (HDM) in early 1960s, and the clinical efficacy has been well-known. However, the major drawbacks of SCIT are necessity of repeated painful injections as well as the risk of severe systemic adverse reactions. Sublingual immunotherapy (SLIT) was developed to resolve these issues. In Japan, Japanese cedar (JC) pollen SLIT-drop was developed initially for treatment of JC pollinosis, and approved for patients of 12 years of age and older in 2014. For adolescent and adult patients with HDM-allergic rhinitis, HDM SLIT-tablet was launched in 2015 and subsequently approved to be also available for pediatric patients (<12 years of age) in 2018. Moreover, JC pollen SLIT-tablet for JC pollinosis was approved in 2018 for all patients with no age limit. Here, we also describe that the formulation technologies of SLIT tablets and distribution of allergens after sublingual administration as well as the development of SLIT drop/tablets.

BSACI guideline for the diagnosis and management of allergic and non-allergic rhinitis (Revised Edition 2017; First edition 2007)

This is an updated guideline for the diagnosis and management of allergic and non-allergic rhinitis, first published in 2007. It was produced by the Standards of Care Committee of the British Society of Allergy and Clinical Immunology, using accredited methods. Allergic rhinitis is common and affects 10-15% of children and 26% of adults in the UK, it affects quality of life, school and work attendance, and is a risk factor for development of asthma. Allergic rhinitis is diagnosed by history and examination, supported by specific allergy tests. Topical nasal corticosteroids are the treatment of choice for moderate to severe disease. Combination therapy with intranasal corticosteroid plus intranasal antihistamine is more effective than either alone and provides second line treatment for those with rhinitis poorly controlled on monotherapy. Immunotherapy is highly effective when the specific allergen is the responsible driver for the symptoms. Treatment of rhinitis is associated with benefits for asthma. Non-allergic rhinitis also is a risk factor for the development of asthma and may be eosinophilic and steroid-responsive or neurogenic and non- inflammatory. Non-allergic rhinitis may be a presenting complaint for systemic disorders such as granulomatous or eosinophilic polyangiitis, and sarcoidoisis. Infective rhinitis can be caused by viruses, and less commonly by bacteria, fungi and protozoa.

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.

Suppression of Allergic Response by CpG Motif Oligodeoxynucleotide–House-Dust Mite Conjugate in Animal Model of Allergic Rhinitis

Background

Although there have been many therapeutic options for allergic disease, the true allergen desensitization remains a challenging goal. The classic immunotherapy has a limited efficacy, is inconvenient, and has a risk of anaphylaxis. Recent reports revealed that immunostimulatory DNA sequences (ISS-oligdeoxynucleotide [ODN], CpG motif) act as a strong Th1 response–inducing adjuvants and that DNA-based vaccination might be an effective therapeutic option. In this study, we investigate whether ISS-ODN/Dermatophagoides farinae (Der f) conjugate has antiallergic effects in the allergic rhinitis mouse model, sensitive to house-dust mites. Der f is the most common allergen-inducing allergic rhinitis in Korea.

Methods

C57BL/6 mice were sensitized with crude extract of Der f. After injection of ISS-ODN or ISS-ODN/Der f conjugate, several parameters of allergic response were evaluated.

Results

Scratching and sneezing symptoms and eosinophilic infiltration into nasal mucosa were suppressed by injection with ISS-ODN only and ISS-ODN/Der f conjugate. Interleukin-5 level was decreased and interferon γ level was increased in nasal lavage fluid by injection of ISS-ODN/Der f conjugate. Der f–specific immunoglobulin E was decreased by injection of ISS-ODN or Der f /ISS-ODN conjugate; however, these were not statistically significant. Transforming growth factor β1 secreted by cultured splenocyte was increased significantly in ISS-ODN/Der f conjugate group.

Conclusion

These results suggest ISS-ODN/Der f conjugate induces an antiallergic effect and induces an increase in transforming growth factor β1 level in the allergic rhinitis model using Der f allergen. Allergic response developed by Der f allergen could be more effectively reduced by injection with ISS-ODN/Der f conjugate than by injection with ISS-ODN only.

Enhanced efficacy of sublingual immunotherapy by liposome-mediated delivery of allergen

Immunotherapy by sublingual administration of allergens provides high patient compliance and has emerged as an alternative to subcutaneous immunotherapy for the treatment of IgE-associated allergic diseases. However, sublingual immunotherapy (SLIT) can cause adverse events. Development of allergen delivery systems enabling more efficient delivery and hence lower allergen load might reduce the adverse events. In the present study, we have investigated neutral and cationic liposomes as delivery systems of ovalbumin (OVA), as a model allergen, in an OVA-induced allergic airway inflammation model. We investigated the liposome carriers' ability to improve tolerance induction of antigens compared to the corresponding dose of free OVA. Mice were treated sublingually over 2 weeks with free or liposome encapsulated OVA followed by intraperitoneal injections and intranasal challenge. Mice sublingually treated with OVA-liposomes showed a significant reduction of airway eosinophilia and splenocyte proliferation in comparison to free OVA. A similar nonsignificant pattern was seen for OVA-specific IgE antibodies. In addition, reduced levels of interferon-γ and interleukin-5 were observed in spleen cell culture supernatants from OVA-liposome-treated mice compared to the sham-treated group. In conclusion, in vivo efficacy data showed that prophylactic SLIT with OVA-liposomes is significantly more effective in preventing allergic inflammation than the corresponding dose of free OVA.

Chinese Guideline on allergen immunotherapy for allergic rhinitis

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

Utility and Comparative Efficacy of Recombinant Allergens Versus Allergen Extract

Allergy immunotherapy (AIT) is the only disease-modifying therapy for the treatment of allergic diseases. Although its efficacy and utility are well-established, the potential for serious adverse events, cumbersome and lengthy treatment protocols, and variability of natural allergen preparations have limited its widespread application. Recent advances in recombinant technology have opened new avenues for the development of AIT vaccines. The purpose of this review is to highlight recent evidence on the use of novel recombinant vaccines and review the mechanisms, efficacy, safety, and limitations of AIT. Emerging evidence suggests that recombinant vaccines may provide a viable treatment alternative that improves on the limitations of natural extract therapy while maintaining efficacy.

Benefit of SLIT and SCIT for Allergic Rhinitis and Asthma

Allergen immunotherapy (AIT) has been in use since more than one century, when Leonard Noon experimentally proved its efficacy in hayfever (Noon, in Lancet 1:1572-3, 1911). Since then, AIT was administered only as subcutaneous injections (SCIT) until the sublingual route (SLIT) was proposed in 1986. The use of SLIT was proposed following several surveys from the USA and UK that repeatedly reported fatalities due to SCIT (Lockey et al. in J Allergy Clin Immunol 75(1): 166, 1985; Lockey et al. in J Allergy Clin Immunol 660-77, 1985; Committee on the safety of medicines. CSM update. Desensitizing vaccines. Br Med J, 293: 948, 1986). These reports raised serious concerns about the safety and the risk/benefit ratio of AIT. Many cases of life-threatening events with SCIT were due to avoidable human errors in administration, but a relevant fraction of them remained unexplained and unpredictable (Aaronson and Gandhi in J Allergy Clin Immunol 113: 1117-21, 2014). Subsequently, in a few years, SLIT gained credibility and was included in the official documents and guidelines (Table 1) (Bousquet et al. in J Allergy Clin Immunol 108(5 Supp):S146-S150, 2001; Canonica et al. in Allergy 64 (Supp 91):1-59, 2009) as a viable alternative to traditional SCIT. Of note, the local bronchial (aerosol) and the intranasal route of administration were attempted after the 1970s as alternatives to SCIT: the bronchial route was soon abandoned due to the poor efficacy and/or side effects, and the local nasal route, although effective and safe, was judged substantially impractical (Canonica and Passalacqua in J Allergy Clin Immunol 111: 437-48, 2003). In contrast to SCIT, SLIT was tested in very large clinical trials (need references), including hundreds of patients and with dose-ranging experimental designs, so that some products (tablets) for grass, mite, and ragweed were officially approved as commercial drugs by regulatory agencies such as the Food and Drug Administration and the European Medicines Agency and the optimal content for the maintenance dose was identified for selected allergens. In parallel, the knowledge on the mechanisms of action of AIT was rapidly refined, leading to further improvements, such as the chemically modified extracts and the use of adjuvants to enhance efficacy and safety. In addition, in the last 10 years, there has been an increasing scientific and clinical interest in AIT applied to food allergies, in particular in children, with the use of orally administered extracts (Albin and Nowak-Węgrzyn in Immunol Allergy Clin North Am 35: 77-100, 2015). The results are so far encouraging, at least for cow's milk, egg, and peanut, although the use of treatment is still restricted to clinical trials or within specialized centers. Finally, the introduction of molecular- or component-resolved diagnosis has allowed detailing the prescription of AIT, by better delineating true sensitization versus cross-reactivity (Canonica et al. in World Allergy Organ J 6(1):17, 2013). This latter point is also in strict relation to the use of recombinant, engineered or highly purified molecules, instead of raw extracts, for the desensitization process.

[Immunological mechanisms of allergen-specific immunotherapy]

Allergen-specific immunotherapy is accompanied by multiple changes on the cellular and humoral level. A shift of Th2 immune responses towards immune responses of the Th1 type, which goes along with an increase of regulatory T cells and B cells, IL-10 as well as reduction of effector cells and eosinophils in the tissue, combined with lower IgE production in favor of higher IgG4 production, are regarded as key mechanisms of allergen-specific immunotherapy . A better understanding of immunologic pathways of specific immunotherapy would be essential for the improvement of this therapy as well as for the development of reliable biomarkers capable to monitor therapeutic responses as well as compliance of the patients.

Critical appraisal of the clinical utility of sublingual immunotherapy in allergy

Since it was introduced by Noon in 1911, allergen-specific immunotherapy or desensitization has been widely prescribed in the management of allergic diseases. Aimed at the etiology, it represents the only effective treatment for allergy. The basic mechanisms of immunotherapy are becoming better understood and allow us to improve this technique in the future. The sublingual immunotherapy as an alternative to subcutaneous route has been widely studied. Several clinical trials confirmed that sublingual immunotherapy is efficient in reducing allergic respiratory symptoms. The sublingual immunotherapy reduces the risk of developing serious side effects due to desensitization. We performed a literature review in order to remind the mechanisms of action and to demonstrate efficacy and tolerability of the sublingual immunotherapy in the treatment of allergic rhinoconjunctivitis and asthma and its impact on the quality of life.

Risk and safety requirements for diagnostic and therapeutic procedures in allergology: World Allergy Organization Statement

One of the major concerns in the practice of allergy is related to the safety of procedures for the diagnosis and treatment of allergic disease. Management (diagnosis and treatment) of hypersensitivity disorders involves often intentional exposure to potentially allergenic substances (during skin testing), deliberate induction in the office of allergic symptoms to offending compounds (provocation tests) or intentional application of potentially dangerous substances (allergy vaccine) to sensitized patients. These situations may be associated with a significant risk of unwanted, excessive or even dangerous reactions, which in many instances cannot be completely avoided. However, adverse reactions can be minimized or even avoided if a physician is fully aware of potential risk and is prepared to appropriately handle the situation. Information on the risk of diagnostic and therapeutic procedures in allergic diseases has been accumulated in the medical literature for decades; however, except for allergen specific immunotherapy, it has never been presented in a systematic fashion. Up to now no single document addressed the risk of the most commonly used medical procedures in the allergy office nor attempted to present general requirements necessary to assure the safety of these procedures. Following review of available literature a group of allergy experts within the World Allergy Organization (WAO), representing various continents and areas of allergy expertise, presents this report on risk associated with diagnostic and therapeutic procedures in allergology and proposes a consensus on safety requirements for performing procedures in allergy offices. Optimal safety measures including appropriate location, type and required time of supervision, availability of safety equipment, access to specialized emergency services, etc. for various procedures have been recommended. This document should be useful for allergists with already established practices and experience as well as to other specialists taking care of patients with allergies.

[Allergen immunotherapy: Mechanisms of action, and therapeutic and socioeconomic impact Consensus of the Asociación Colombiana de Alergia, Asma e Imunología]

Allergies comprise a set of highly prevalent diseases. When allergic processes are not controlled, they can endanger patients' health and lives, and have an important economic and social impact. The aim of this paper is to present a practical consensus of the scientific evidence on the use of immunotherapy in allergic diseases. A collaborative review made by various institutes and universities in Colombia was carried out upon request of the Asociación Colombiana de Alergia, Asma e Imunología, led by general practitioners, allergists, immunologists, internists and paediatricians with experience in the field of allergies. As a result, based on current national and international scientific evidence, we describe in detail what immunotherapy is about, its indications, contraindications and its economic and health benefits. Conclusions show immunotherapy as a clinically effective and safe treatment, which can substantially reduce the cost of the overall treatment of allergic patients.

Local Side Effects of Sublingual and Oral Immunotherapy

Sublingual immunotherapy (SLIT) is increasingly used worldwide, and several products have been recently registered as drugs for respiratory allergy by the European Medicine Agency and the Food and Drug Administration. Concerning inhalant allergens, the safety of SLIT is overall superior to that of subcutaneous immunotherapy in terms of systemic adverse events. No fatality has been ever reported, and episodes of anaphylaxis were described only exceptionally. Looking at the historical and recent trials, most (>90%) adverse events are "local" and confined to the site of administration. For this reason, a specific grading system has been developed by the World Allergy Organization to classify and describe local adverse events. There is an increasing amount of literature concerning oral desensitization for food allergens, referred to as oral immunotherapy. Also, in this case, local side effects are predominant, although systemic adverse events are more frequent than with inhalant allergens. We review herein the description of local side effects due to SLIT, with a special focus on large trials having a declared sample size calculation. The use of the Medical Dictionary for Regulatory Activities nomenclature for adverse events is mentioned in this context, as recommended by regulatory agencies. It is expected that a uniform classification/grading of local adverse events will improve and harmonize the surveillance and reporting on the safety of SLIT.

Sublingual Immunotherapy: A Useful Tool for the Allergist in Private Practice

This is a review of the author's experience with Sublingual Immunotherapy in a private office setting. Sublingual Immunotherapy should be considered by any allergy practitioner as a useful tool. Sublingual Immunotherapy is safe while at the same time it is effective. It enables the practitioner to treat asthmatics and young children without the concerns implicit with allergy injections.

Safety profile of sublingual immunotherapy

Sublingual immunotherapy (SLIT) was proposed for clinical practice about 20 years ago with the main aim of improving the safety and avoiding the adverse effects of traditional treatment for allergic airways disease. To date, 32 randomized controlled trials and 6 postmarketing surveys have been published that provide a robust documentation of the safety profile of the treatment.Looking at the randomized trials it emerges that the more frequent adverse event of SLIT is oral itching or swelling, followed by gastrointestinal complaints. These adverse events are invariably described as mild and easily managed by adjusting the dose. Relevant systemic adverse events (asthma, urticaria, angioedema) occur sporadically and, with the exception of oral/gastrointestinal adverse events, the incidence of adverse events seems not to differ between the placebo and active groups. The safety profile of SLIT does not differ between adults and children.The postmarketing surveys consistently show that the incidence of adverse events associated with SLIT is less than 10%, corresponding to less than 1 adverse event per 1000 doses, and is thus quite superior to the safety profile of subcutaneous immunotherapy. Of note, the most recent data show that the rate of adverse events with SLIT is not increased in children below the age of 5 years.

Pharmacodynamic and pharmacokinetic evaluation of house dust mite sublingually administered immunotherapy tablet in the treatment of asthma

INTRODUCTION

Sublingual immunotherapy (SLIT) for house dust mite (HDM) allergy has an evidence of efficacy demonstrated by meta-analyses, but marked differences are reported between the various SLIT products. The standardized quality (SQ) HDM sublingual tablet containing Dermatophagoides pteronyssinus and Dermatophagoides farinae in a 1:1 ratio (MK-8237) is a qualitative advance for SLIT products.

AREAS COVERED

The rationale for developing the HDM tablets is discussed against the other available SLIT products, analyzing the clinical data on efficacy and safety obtained by controlled trials.

EXPERT OPINION

Following preliminary Phase I and II studies, a double-blind, placebo-controlled trial on 604 patients with mite-induced asthma, aged more than 14 years and treated by inhaled budesonide, was performed using one of three active doses (1, 3 or 6 SQ) or placebo. The results showed a significant mean difference between 6 SQ-HDM and placebo in the reduction in daily budesonide dose of 81 µg (p = 0.004), with relative mean and median reductions of 42 and 50% for 6 SQ-HDM and 15 and 25% for placebo, respectively. Safety was very good, with no report of anaphylactic reaction. These findings suggest a role to the HDM SLIT tablets in the treatment of patients with mite-induced asthma.

Allergen Immunotherapy: History and Future Developments

Allergen immunotherapy (AIT) was introduced in clinical practice more than 100 years ago. The clinical effectiveness in allergic rhinitis (and asthma) and in hymenoptera allergy was apparent early on but it was not until the mid-1900s that randomized placebo-controlled trials proved its efficacy. In the 1980s, sublingual immunotherapy (SLIT) was accepted in official guidelines. The availability of safer routes, such as SLIT, prompted increasing investigation of AIT for food allergy. The introduction of molecular-based diagnosis introduced the possibility of better targeted prescription of AIT. Other approaches are being explored, such as immunogenic peptides, recombinant allergens, and adjuvants.

Specific immunotherapy for allergic rhinitis in children

PURPOSE OF REVIEW

Allergic rhinitis is a highly prevalent inflammatory disease affecting 20-40% of the children worldwide. Allergen-specific immunotherapy (SIT) is an effective treatment for allergic rhinitis. This article reviews the recent advances in SIT for children.

RECENT FINDINGS

In current clinical practice, immunotherapy is delivered as either subcutaneous immunotherapy or sublingual immunotherapy (SLIT). Most meta-analyses and reviews concluded a trend that subcutaneous immunotherapy was better than SLIT in reducing symptoms of allergic rhinitis and rescue medication use, however, SLIT has a better safety profile than subcutaneous immunotherapy. Additionally, the absence of pain on administration of therapy is a character of SLIT, which is well suited for children. T regulatory cells, especially Tr1 cells that secrete interleukin-10 and induce production of immunoglobulin G4, play a role during SIT.

SUMMARY

Although there is substantial evidence for effectiveness of both subcutaneous immunotherapy and SLIT, safer and more effective SIT approaches are needed. New approaches to improve SIT include omalizumab pretreatment, use of recombinant allergens, and alternate routes of administration.

Allergen immunotherapy, routes of administration and cytokine networks: an update

Allergen immunotherapy is a disease-modifying therapy, effective for the treatment of allergic rhinitis, allergic asthma, conjunctivitis or stinging insect allergy. Allergen immunotherapy involves the administration of increasing doses of allergens with the aim of ameliorating the allergic response. Although precise underlying mechanisms of the induction of immune tolerance remain unclear, immunotherapy has been associated with the induction of distinct subsets of Tregs that eventually lead to peripheral tolerance by inducing a deviation from Th2 to Th1 immune responses. This review focuses on the current knowledge of the mechanisms of immunotherapy in relationship to different routes of administration and also provides a unifying view.

Safety and efficacy of a new regimen of short-term oral immunotherapy with Cry j 1-galactomannan conjugate for Japanese cedar pollinosis: a prospective, randomized, open-label study

BACKGROUND

Short-term oral immunotherapy (OIT) using the Cry j1-galactomannan conjugate for Japanese cedar pollinosis may be effective and relatively safe. However, a treatment regimen has not been established. In the present study, we examined a new OIT regimen with a build-up phase and extended the maintenance phase of OIT to the peak period of the pollen season to enhance the therapeutic effect and safety of OIT.

METHODS

A prospective, randomized, open-label trial was conducted over a period of 4 months. Participants were randomly divided into two groups. The OIT group comprised 23 subjects. The build-up phase was initiated 1 month before the expected pollen season. The maintenance phase was continued for 51 days during the peak pollen season. The control group comprised 24 subjects. The symptoms and medication score, levels of allergen-specific serum antibodies throughout the pollen season, and adverse effects with OIT were evaluated.

RESULTS

Participants receiving OIT showed significant improvements in total symptom scores, medication score, and total symptom-medication scores throughout the pollen season compared with the control group. The levels of allergen-specific serum IgG4 were significantly increased in the OIT group but not in the control group throughout the cedar pollen season. Importantly, no severe adverse effects were observed with OIT.

CONCLUSIONS

The new regimen of short-term OIT using the Cry j1-galactomannan conjugate for Japanese cedar pollinosis is effective, relatively safe and induces immune tolerance. Thus, OIT using allergen-galactomannan conjugates may provide a rapid, effective, and thus convenient immunotherapy for pollinosis instead of SLIT or SCIT.

Safety evaluation of standardized allergen extract of Japanese cedar pollen for sublingual immunotherapy

Japanese cedar (JC) pollinosis is caused by Japanese cedar pollen (JCP) and most common seasonal allergic disease in Japan. Subcutaneous immunotherapy (SCIT) with allergen extract of JCP (JCP-allergen extract) is well established for JC pollinosis treatment with improvement of symptoms. However, major drawbacks for SCIT are repeated painful injections, frequent hospital visits and anaphylactic risk. Currently, sublingual immunotherapy (SLIT) has received much attention as an advanced alternative application with lower incidence of systemic reactions because the liquid or tablet form of allergen is placed under the tongue. The aim of this study was safety evaluation of standardized JCP-allergen extract currently developed for SLIT in JC pollinosis. JCP-allergen extract showed no potential genotoxicity. No systemic effects were observed in rats administered JCP-allergen extract orally for 26 weeks followed by 4-week recovery period. Mild local reactions such as hyperplasia and increased globule leukocytes resulting from vehicle (glycerin)-induced irritation were observed in stomach. No-observed-adverse-effect level was greater than 10,000 JAU/kg/day for systemic toxicity, equivalent to 300-fold the human dose. No local irritation was found in rabbits oral mucosae by 7-day sublingual administration. These results demonstrate the safe profile of standardized JCP-allergen extract, suggesting it is suitable for SLIT in JC pollinosis.

Ragweed-induced allergic rhinoconjunctivitis: current and emerging treatment options

Ragweed (Ambrosia spp.) is an annually flowering plant whose pollen bears high allergenic potential. Ragweed-induced allergic rhinoconjunctivitis has long been seen as a major immunologic condition in Northern America with high exposure and sensitization rates in the general population. The invasive occurrence of ragweed (A. artemisiifolia) poses an increasing challenge to public health in Europe and Asia as well. Possible explanations for its worldwide spread are climate change and urbanization, as well as pollen transport over long distances by globalized traffic and winds. Due to the increasing disease burden worldwide, and to the lack of a current and comprehensive overview, this study aims to review the current and emerging treatment options for ragweed-induced rhinoconjunctivitis. Sound clinical evidence is present for the symptomatic treatment of ragweed-induced allergic rhinoconjunctivitis with oral third-generation H1-antihistamines and leukotriene antagonists. The topical application of glucocorticoids has also been efficient in randomized controlled clinical trials. Combined approaches employing multiple agents are common. The mainstay of causal treatment to date, especially in Northern America, is subcutaneous immunotherapy with the focus on the major allergen, Amb a 1. Beyond this, growing evidence from several geographical regions documents the benefit of sublingual immunotherapy. Future treatment options promise more specific symptomatic treatment and fewer side effects during causal therapy. Novel antihistamines for symptomatic treatment are aimed at the histamine H3-receptor. New adjuvants with toll-like receptor 4 activity or the application of the monoclonal anti-immunoglobulin E antibody, omalizumab, are supposed to enhance conventional immunotherapy. An approach targeting toll-like receptor 9 by synthetic cytosine phosphate–guanosine oligodeoxynucleotides promises a new treatment paradigm that aims to modulate the immune response, but it has yet to be proven in clinical trials.

The evolution of allergen and non-specific immunotherapy: past achievements, current applications and future outlook

Recent epidemiological studies estimated that more than 30% of European suffer from allergic rhinitis or conjunctivitis, while up to 20% suffer from asthma and 15% from allergic skin conditions, while for many other regions the prevalence is increasing. Allergen immunotherapy represents the only available treatment that can modify the allergic disease process, and thus is worth considering as a treatment in affected individuals. A beneficial effect of allergen immunotherapy has been shown in both adults and children affected by allergic rhinitis, allergic conjunctivitis, allergic asthma and hymenoptera venom allergy. The present study represents an overview on allergen immunotherapy, focusing on the principal aspects of the use of immunotherapy in the past, its recent clinical applications and future outlook.

Safety, tolerability and clinical efficacy of ultra-rush sublingual immunotherapy among patients suffering from allergic rhinitis

BACKGROUND

Conventional immunotherapy for allergy with 3-5 years of treatment period has poor compliance. Ultra-rush sublingual immunotherapy with a shorter period of treatment can have better compliance. There are very few studies on ultra-rush sublingual immunotherapy all over the world.

OBJECTIVES

(1) To determine allergen sensitivity among allergic rhinitis patients. (2) To assess safety, tolerability and clinical efficacy of ultra-rush sublingual immunotherapy.

METHODS

The present study was conducted in Allergy clinic, KIMS Hospital & Research Centre, Bangalore, India from January 2010 to June 2011. After obtaining Institutional Ethics Committee approval, 40 allergic rhinitis patients (according to ARIA guidelines) in the 18-60 years age group who were positive for aeroallergens in skin prick test were recruited for ultra-rush sublingual immunotherapy (20min initial phase and 4-month maintenance phase) and followed for 8 months with symptom and treatment diary.

RESULTS

Out of 40 patients, the majority, 36 (90.00%) patients were sensitive to house dust mites. Six patients had seven immediate adverse reactions and seven patients had eight delayed adverse reactions. All subsided without medication or with symptomatic oral medications. All patients tolerated ultra-rush SLIT and there was significant decrease in both symptom-score and treatment received in these patients.

CONCLUSION

Ultra-rush SLIT regimen has excellent safety, tolerability and clinical efficacy among allergic rhinitis patients.

Investigational drugs for the treatment of allergic rhinitis

INTRODUCTION

Allergic rhinitis is characterized by paroxysms of sneezing, rhinorrhea and nasal obstruction. Its prevalence is increasing in industrialized countries worldwide and imposes a significant economic burden as a result of reduced school performance, work productivity and medical expenses. Allergic rhinitis impairs the quality of life of those affected, and current treatment regimens are inadequate for those whose symptoms are severe or refractory to standard drug therapies. They mainly include symptom control with intranasal glucocorticoids, oral and intranasal antihistamines.

AREAS COVERED

This article provides a review of the most current literature on research that has focused on improving the efficacy of current treatment regimens and developing new drugs. It also provides the reader with an improved understanding of the pathogenesis of allergic rhinitis, including the inflammatory mediators and cell types involved, which has led to novel treatment options that are under investigation. These new drugs aim to alter the immunologic response to allergens in order to achieve greater clinical efficacy.

EXPERT OPINION

It is our opinion that despite developments in new therapies, a multidrug approach is vital for successful treatment of allergic rhinitis. Furthermore, immunotherapy in the form of sublingual immunotherapy is a promising additional therapeutic approach that will potentially make immunotherapy available to a wider selection of eligible patients with allergic rhinitis.

Phase I/II study of oral immunotherapy with Cry j1-galactomannan conjugate for Japanese cedar pollinosis

OBJECTIVE

Among many immunotherapeutic approaches, oral immunotherapy (OIT) is thought to be an effective route for desensitization against a variety of allergens. However, there is little evidence that OIT is effective for airway allergic diseases such as pollen allergy. Thus, in the present study, we assessed the safety, efficacy and immune response of OIT using the Cry j1-galactomannan conjugate for Japanese cedar pollen allergy.

METHODS

An open trial was conducted over a period of 4 months. The OIT group comprised of 23 subjects. Treatment was initiated 1 month before the estimated pollen season and continued for 1 month. The control group (the pharmacological treatment group without OIT) comprised of 11 subjects. The symptoms and medication score, levels of allergen-specific serum antibodies, cellular components of lymphocytes and cytokine production from peripheral blood mononuclear cells (PBMCs) were evaluated throughout the pollen season.

RESULTS

The participants receiving OIT treatment showed significant improvements in total symptom scores and symptom-medication scores during the pollen season compared with the control group. The levels of allergen-specific serum IgG4 and IL-10 production in PBMCs were significantly increased in the OIT group compared with that in the control group. Importantly, no severe adverse effects were observed in the participants receiving OIT treatment.

CONCLUSION

Short-term OIT using the Cry j1-galactomannan conjugate is effective, relatively safe and induces tolerant immune responses such as increased allergen-specific serum IgG4 and IL-10 production in PBMCs. These results suggest that OIT using allergen-galactomannan conjugates may provide a rapid, effective, and safe immunotherapy regimen for cedar pollen allergy.

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.

Oralair(®): a causal treatment for grass pollen-induced allergic rhinoconjunctivitis

Grass pollen-induced allergic rhinoconjunctivitis is a common disease, comprising more than just the classic symptoms of nasal obstruction, sneezing, rhinorrhea and itchy, watery eyes. Sufferers deal with severe impairments in daily life. Allergic rhinoconjunctivitis is also considered an important risk factor in the development of asthma. Allergen avoidance, medication for symptomatic treatment and allergen-specific immunotherapy are cornerstones in therapeutic management, but immunotherapy is the only available treatment that is able to affect the natural course of allergy. In recent decades, clinical trials have investigated the efficacy and safety of subcutaneous immunotherapy. To date, efforts have been made to develop more convenient routes of administration. Substantial improvement may be achieved through the application of sublingual tablets. This article discusses the development process of immunotherapy and the clinical background of the Oralair(®) (Stallergènes, Hauts-de-Seine, France) five-grass pollen tablet. Furthermore, it outlines this tablet's efficacy and safety properties.

Oral immunotherapy with transgenic rice seed containing destructed Japanese cedar pollen allergens, Cry j 1 and Cry j 2, against Japanese cedar pollinosis

Transgenic rice accumulating the modified major Japanese cedar pollen allergens, Cryptomeria japonica 1 (Cry j 1) and Cryptomeria japonica 2 (Cry j 2), which were deconstructed by fragmentation and shuffling, respectively, in the edible part of the seed was generated by transformation of a good-tasting rice variety, 'Koshihikari'. These modified cedar pollen antigens were deposited in ER-derived protein bodies (PB-I), which are suitable for delivery to the mucosal immune system in gut-associated lymphoid tissue when orally administered because antigens bioencapsulated in PB-I are resistant against hydrolysis by intestinal enzymes and harsh environments. Mice fed transgenic seeds daily for three weeks and then challenged with crude cedar pollen allergen showed marked suppression of allergen-specific CD4(+) T-cell proliferation, IgE and IgG levels compared with mice fed nontransgenic rice seeds. As clinical symptoms of pollinosis, sneezing frequency and infiltration of inflammatory cells such as eosinophils and neutrophils were also significantly reduced in the nasal tissue. These results imply that oral administration of transgenic rice seeds containing the structurally disrupted Cry j 1 and Cry j 2 antigens, serving as universal antigens, is a promising approach for specific immunoprophylaxis against Japanese cedar pollinosis.

Efficacy and safety of sublingual immunotherapy in Asian children

OBJECTIVE

Sublingual immunotherapy is currently accepted as a suitable alternative to subcutaneous immunotherapy because of its easy and painless administration and improved safety. Many clinical trials have demonstrated that sublingual immunotherapy is an effective and safe treatment for pollen or mite allergic rhinitis. However, there have been very few studies overall on children with allergic rhinitis who are sensitized to house-dust mites in Asia. The purpose of the present study was to investigate the efficacy and safety of sublingual immunotherapy in children with allergic rhinitis to house-dust mites.

METHODS

A total of 112 patients under the age of 15 who had allergic rhinitis to Dermatophagoides pteronyssinus and Dermatophagoides farinae were included. All patients were treated with sublingual immunotherapy (Staloral(®)). Symptom scores and quality of life were evaluated by questionnaires until one year after sublingual immunotherapy. The medication score was assessed monthly using a diary medication card and serologic tests were evaluated before and 6 and 12 months after treatment. Adverse effects and compliance were also investigated.

RESULTS

All nasal and non-nasal symptoms and quality of life were significantly improved after treatment. The total medication score was decreased significantly after sublingual immunotherapy. There was no significant change in serologic tests. Some minor adverse effects were reported, however there were no systemic reactions. The drop-out rate was 21%.

CONCLUSIONS

Sublingual immunotherapy is a valuable therapy for the treatment of allergic rhinitis in Asian children sensitized to house-dust mites.

Therapeutic effects and biomarkers in sublingual immunotherapy: a review

Immunotherapy is considered to be the only curative treatment for allergic diseases such as pollinosis, perennial rhinitis, asthma, and food allergy. The sublingual route is widely applied for immunotherapy for allergy, instead of the conventional administration by subcutaneous route. A recent meta-analysis of sublingual immunotherapy (SLIT) has shown that this approach is safe, has positive clinical effects, and provides prolonged therapeutic effects after discontinuation of treatment. However, the mechanism of SLIT and associated biomarkers are not fully understood. Biomarkers that change after or during SLIT have been reported and may be useful for response monitoring or as prognostic indicators for SLIT. In this review, we focus on the safety, therapeutic effects, including prolonged effects after treatment, and new methods of SLIT. We also discuss response monitoring and prognostic biomarkers for SLIT. Finally, we discuss immunological mechanisms of SLIT with a focus on oral dendritic cells and facilitated antigen presentation.

Nanoparticulate adjuvants and delivery systems for allergen immunotherapy

In the last decades, significant progress in research and clinics has been made to offer possible innovative therapeutics for the management of allergic diseases. However, current allergen immunotherapy shows limitations concerning the long-term efficacy and safety due to local side effects and risk of anaphylaxis. Thus, effective and safe vaccines with reduced dose of allergen have been developed using adjuvants. Nevertheless, the use of adjuvants still has several disadvantages, which limits its use in human vaccines. In this context, several novel adjuvants for allergen immunotherapy are currently being investigated and developed. Currently, nanoparticles-based allergen-delivery systems have received much interest as potential adjuvants for allergen immunotherapy. It has been demonstrated that the incorporation of allergens into a delivery system plays an important role in the efficacy of allergy vaccines. Several nanoparticles-based delivery systems have been described, including biodegradable and nondegradable polymeric carriers. Therefore, this paper provides an overview of the current adjuvants used for allergen immunotherapy. Furthermore, nanoparticles-based allergen-delivery systems are focused as a novel and promising strategy for allergy vaccines.

Efficacy of sublingual immunotherapy versus subcutaneous injection immunotherapy in allergic patients

While it is generally accepted that Subcutaneous Injection Immunotherapy (SCIT) and Sublingual Immunotherapy (SLIT) are both efficacious, there is not yet a significant amount of information regarding their comparative efficacy. In this paper, we performed a retrospective chart review and compared treatment results in two groups of patients (both with nasal allergies with or without asthma) that were treated either with SCIT or SLIT. Both treatment modalities were found to be of similar efficacy.

Clinical improvement after escalation for sublingual immunotherapy (SLIT)

Sublingual immunotherapy (SLIT) permits rapid antigen escalation with an improved safety profile over that of subcutaneous immunotherapy. Outcomes for SLIT in terms of the timing of clinical improvement were investigated in a retrospective review of patients undergoing SLIT who completed quality of life (QOL) and medication-use questionnaires at baseline and immediately after antigen escalation was performed. A subset of patients (n = 24) also completed maintenance-phase questionnaires. Paired post-escalation data (mean 5.5 weeks; N = 38) demonstrated improvement (p< 0.05) in overall QOL scores and in 6 of 14 symptom domains. Maintenance phase data (n = 24) revealed significant improvements in total QOL scores and in 5 symptom domains. A significant reduction in nasal steroid use was also demonstrated during the maintenance phase of treatment (p < 0.05). Significant improvement is seen immediately post-escalation in SLIT patients. This improved QOL appears to be maintained, and perhaps even increases, during the maintenance phase, with decreased nasal steroid use.

Regulatory T cells induced by mucosal B cells alleviate allergic airway hypersensitivity

Asthma is one of the most common chronic airway inflammatory diseases. The induction of immunologic tolerance via mucosa has been used for treating allergic diseases. B cells, which comprise the major cell population in Peyer's patches, were shown to induce the development of regulatory T (Treg) cells. This study investigated the role of B cells in Peyer's patches regarding the induction of tolerance and Treg cell functions. An in vitro suppressive assay and ELISA were used to evaluate the function of T cells stimulated by Peyer-patch B cells (Treg-of-B cells). The therapeutic potential of Treg-of-B cells was then evaluated by an animal model of airway inflammation. Treg-of-B cells were found to exert a suppressive function on T-cell proliferation. Antigen-loaded B cells isolated from Peyer's patches were more tolerogenic, and had the potential to generate more suppressive Treg-of-B cells via the production of IL-10 and cell-cell contacts. Treg-of-B cells expressed cytotoxic T lymphocyte antigen 4, inducible costimulator, OX40 (CD134), programmed death 1, and TNF-RII, and produced lower concentrations of IL-2 and higher concentrations of IL-10. In a murine model of asthma, an adoptive transfer of Treg-of-B cells before or after immunization sufficiently suppressed Th2 cytokine production and eosinophilic infiltration, and alleviated asthmatic symptoms. B cells isolated from gut-associated lymphoid tissues can generate regulatory T cells that may be important in oral tolerance, and that may be applicable to the alleviation of allergic symptoms.

Specific immunotherapy in children: the evidence

Specific immunotherapy (SIT) is the only treatment able to not only act on the symptoms of allergy but also act on the causes. At present, SIT may be administered in two forms: subcutaneous (SCIT) and sublingual immunotherapy (SLIT). SCIT represents the standard modality of treatment while SLIT has recently been introduced into clinical practice and today represents an accepted alternative to SCIT. The main advantages of SIT that are lacking with drug treatment are long-lasting clinical effects and alteration of the natural course of the disease. This prevents the new onset of asthma in patients with allergic rhinitis and the onset of new sensitizations. The mechanism of action of both routes is similar; they modify peripheral and mucosal Th2-responses into a prevalent Th1-polarization with subsequent reduction of the allergic inflammatory reaction. Both have long-term effects for years after they have been discontinued, although for SLIT these evidences are insufficient. To date several guidelines have defined indications, controindications, side-effects, and clinical aspect for SCIT and SLIT. New forms of immunotherapy, allergen products and approaches to food allergy and atopic eczema represents the future of SIT.