Subcutaneous and sublingual immunotherapy:Where do we stand?

Though symptoms of allergic diseases can be reduced by the use of drugs such as corticosteroids,antihistamines or leukotrien antagonists,the only treatment directed to change the natural course of allergic disease is allergen-specific immunotherapy(SIT). Its efficacy can last years after the cessassion of the treatment.SIT brings on regulatory T cells with the capacity to generate interleukin-10 and transforming growth factor-b,restricts activation of mast cells and basophils,and shifts antibody isotype from Ig E to the noninflammatory type immunoglobulin G4. Subcutaneous(SCIT)and sublingual(SLIT) immunotherapy are the two most used ways at the present for applying SIT. These two treatments were demonstrated to be effective on reducing symptoms and medication use,in prevention of new sensitizations and in protecting from progression of rhinitis to asthma. The safety of SLIT appears to be better than SCIT although there have been a few head to head comparisons. In order to overcome compliance problems or possible systemic side effects which maybe faced during this long-term treatment,recent investigations have been focused on the implementation of allergens in quite efficacious and safer ways.