Allergen immunotherapy now and in the future

Background: Subcutaneous (SCIT) and sublingual (SLIT) immunotherapy provide effective treatment for allergic rhinitis and allergic asthma with clinical improvement following an adequate course of therapy persisting in most patients for years after treatment is discontinued. However, both require prolonged courses of therapy and many or most patients either do not begin or stop long before they have completed the prescribed course of treatment. Methods: Based on review of the recent medical literature, the current status of SCIT and SLIT was reviewed as well as new approaches to allergy immunotherapy (AIT) that have promise to overcome the safety and inconvenience concerns of both the current approaches. Results: New approaches to AIT include application of extracts to the skin with patches, injection into inguinal lymph nodes, alterations in the allergen molecules by chemical treatment or recombinant technology to make them less reactive with specific IgE, shifting the immune response by stimulation of toll-like receptors or suppression of Th2 responses, and finally by adjuvants such as probiotics and vitamin D. Conclusions: Current forms of immunotherapy require years of treatment. New approaches, although differing markedly in their approach to AIT, all offer marked reduction in the required period of treatment. Hopefully, some of these new approaches will prove safe and effective and obtain approval for general use. If approved, they should make AIT more widely utilized to the benefit of the allergic population.