Allergen-Specific Immunotherapy

Allergen immunotherapy (AIT) has been used as a desensitizing therapy for allergic diseases for over 100 years and represents the only potentially curative treatment. There have been major progresses in understanding the complex regulatory mechanisms of immune-mediated diseases and this has led to increasingly targeted therapeutic approaches. The mechanisms of AIT include the desensitization effects, modulation of T and B cell responses, inhibition of migration into tissues, and mediator releasing of eosinophils, basophils, and mast cells. AIT acts on dendritic cells and on regulatory T (Treg) cells that have a key role in the immunological processes for achieving allergen tolerance. The efficacy of AIT has been shown in allergen-driven diseases. Subcutaneous immunotherapy is recommended in children with allergic rhinitis, allergic asthma, and hymenoptera venom allergy. Oral immunotherapy has been used for food allergies. Sublingual immunotherapy is recommended for allergic rhinitis, and allergic asthma particularly due to house dust mites associated with allergic rhinitis. Other indications are debated because of the heterogeneity of products and drawbacks of studies.