The consideration of immunotherapy in the treatment of allergic asthma

TLR9-based immunotherapy for allergic disease

A significant amount of data generated over the last few years supports the contention that Toll-like receptor (TLR) 9-based immunotherapy is effective in the prevention and treatment of animal models of allergic disorders. We will review here our experience with two distinct therapeutic strategies: TLR9-based immunomodulation and TLR9-based vaccination. Immunomodulation of allergic inflammation by TLR9 ligand (TLR9-L) is transient. It prevents both the early and late phases of the allergic reaction in experimental models of allergic asthma, rhinitis, and conjunctivitis. It also reverses ongoing allergic inflammation. Indoleamine 2.3-dioxygenase, the rate-limiting enzyme of tryptophan, is induced by TLR9-L and mediates, in part, these anti-inflammatory effects. TLR9-based immunomodulation is independent of allergens and, therefore, has a potential therapeutic advantage in a broad spectrum of allergic patients. On the other hand, TLR9-based vaccination therapy is an allergen-specific mode of immunotherapy, which provides long-term inhibition of allergen-specific hypersensitivities. Current clinical trials with TLR9-based immunotherapy demonstrate high immunogenic and therapeutic efficacy, as well as improved safety when compared with conventional allergen desensitization. Thus, if proven efficient, therapeutic strategies with TLR9-L may revolutionize the current treatment of allergic diseases.

Immunotherapy in the age of anti-IgE

Recent results of allergen immunotherapy research have continued to validate efficacy and have also demonstrated a truly preventive aspect for this treatment. This review summarizes the basic principles of effective allergen immunotherapy and highlights some of the advances that have been published in the past year. These studies show that allergen immunotherapy, when done appropriately and properly, not only causes a decrease in symptoms and use of medication as well as an improved quality of life, but that the progression of disease from allergic rhinitis to asthma is substantially decreased and the development of new allergies is diminished. In addition, laboratory studies continue to demonstrate significant changes in the immune system with a shift in the immune pathway from TH2 toward a TH1 response. The impact of anti-IgE as a therapeutic agent with allergen immunotherapy is also be reviewed.

Respiratory allergy

Allergic rhinitis (AR) and asthma are common respiratory allergic disorders which are increasing globally more in developed countries. Although much has been written about childhood asthma and guidelines published by various international and national fora, not much information is available on AR. This is most common in children, is a significant risk factor for developing asthma, is a common comorbidity with asthma and affects quality of life. This paper highlights the risk factors for developing respiratory allergy asthma and AR, linkages between them and the management issues, particularly in relation to the allergic or allergological aspects as they have important bearing on management of children suffering from respiratory allergy. Specific immunotherapy (SIT) is re-emerging as useful therapy which alone has the potential to modify the natural history of disease and prevent the 'allergic march'. Timely diagnosis, correct management including timely referrals can ensure good quality life for those suffering from respiratory allergies.