Sublingual immunotherapy: where do we stand? Present and future

The efficacy of sublingual immunotherapy for allergic diseases in Asia

Sublingual immunotherapy (SLIT) has been proven to be safe and effective from an abundance of Western literature, but data from Asia is less complete. This review aims to examine the basic science, safety and efficacy of SLIT in Asian patients, and to determine future research needs in Asia. We performed a literature search on PUBMED, Scopus, and Cochrane Library database for articles on SLIT originating from Asian countries through Nov 2017. There were 18 randomized, double-blind, placebo-controlled trials, of which 9 involved solely paediatric subjects. Overall, sublingual immunotherapy is safe and is efficacious in Asian populations in allergic rhinitis (AR) and asthma. House dust-mite SLIT is effective in both mono- and polysensitized AR patients. Efficacy of SLIT is comparable to subcutaneous immunotherapy. Data on long term efficacy is lacking. A disproportionate majority of research originates from China and Japan, reflecting an asymmetry of access to SLIT within Asia. Significant disparities exist in the development of the allergy speciality, prescription patterns of SLIT, and pharmacological potencies of different SLIT products within and between Asian nations. We conclude that current available evidence suggests SLIT is efficacious in Asians but data quality of evidence is hampered by non-placebo controlled studies with methodological limitations. More data is needed in South and Southeast Asian populations. Future efforts may be directed towards improving access to SLIT in developing countries, standardization of SLIT dosage, and evaluating long term clinical outcomes.

Clinical efficacy of immunotherapy in allergic rhinitis

BACKGROUND

Aeroallergen immunotherapy (AIT) should be considered for patients who exhibit symptoms of allergic rhinitis (AR), rhinoconjunctivitis, and/or asthma after natural exposure to allergens and who also demonstrate specific immunoglobulin E antibodies against relevant allergens.

METHODS

In this paper, clinical efficacy of immunotherapy in allergic rhinitis is reviewed.

RESULT

Subcutaneous allergen immunotherapy (SCIT) is effective for seasonal and perennial AR. Sustained effectiveness requires several years of treatment. SCIT may prevent the development of allergic asthma in children with AR. Sublingual allergen immunotherapy (SLIT) is currently considered an alternative treatment to the subcutaneous route. The use of SLIT has been included in international guidelines for the treatment of AR with or without conjunctivitis.

CONCLUSION

Patients treated with SCIT are at risk of both local and systemic adverse reactions; however, in most cases, symptoms are readily reversible if they are recognized early and treated promptly. The safety profile of SLIT is good; therefore, SLIT can be self-administered by patients in their homes. In this article, we reviewed the efficacy and safety of allergen immunotherapy.

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.

Allergen immunotherapy for allergic respiratory diseases

Allergen specific immunotherapy involves the repeated administration of allergen products in order to induce clinical and immunologic tolerance to the offending allergen. Immunotherapy is the only etiology-based treatment that has the potential for disease modification, as reflected by longterm remission following its discontinuation and possibly prevention of disease progression and onset of new allergic sensitizations. Whereas subcutaneous immunotherapy is of proven value in allergic rhinitis and asthma there is a risk of untoward side effects including rarely anaphylaxis. Recently the sublingual route has emerged as an effective and safer alternative. Whereas the efficacy of SLIT in seasonal allergy is now well-documented in adults and children, the available data for perennial allergies and asthma is less reliable and particularly lacking in children. This review evaluates the efficacy, safety and longterm benefits of SCIT and SLIT and highlights new findings regarding mechanisms, potential biomarkers and recent novel approaches for allergen immunotherapy.

Sublingual immunotherapy: other indications

Sublingual immunotherapy (SLIT) represents a significant advance and it seems particularly suitable in pediatric patients. There are favorable results for food allergy in controlled trials. For latex allergy, the results of several trials are encouraging. For atopic dermatitis, previous experience with subcutaneous immunotherapy and some earlier trials suggest the possible application of SLIT in children with mild to moderate dermatitis and sensitization to dust mite, but this recommendation is considered insufficiently evidence based. In hymenoptera allergy, the only trial available is a proof-of-concept study in large local reactions that needs to be confirmed in well-controlled studies.

Clinical immunology review series: an approach to desensitization

Allergen immunotherapy describes the treatment of allergic disease through administration of gradually increasing doses of allergen. This form of immune tolerance induction is now safer, more reliably efficacious and better understood than when it was first formally described in 1911. In this paper the authors aim to summarize the current state of the art in immunotherapy in the treatment of inhalant, venom and drug allergies, with specific reference to its practice in the United Kingdom. A practical approach has been taken, with reference to current evidence and guidelines, including illustrative protocols and vaccine schedules. A number of novel approaches and techniques are likely to change considerably the way in which we select and treat allergy patients in the coming decade, and these advances are previewed.