| Summary: | Allergen-specific immunotherapy remains the only causal treatment of allergic disease to date. Its efficacy
in symptom reduction was demonstrated in double blind, placebo-controlled studies of allergic
rhinoconjunctivitis, allergic asthma, and Hymenoptera venom hypersensitivity, including long-term
effects after discontinuation of treatment. In addition, immunotherapy decreases the risk of developing
new sensitisations to aeroallergens in monosensitised patients and allergic asthma in patients with mere
allergic rhinitis. The mechanism of immunotherapy entails redirection of the T lymphocyte response from
a T helper cell Type 2 phenotype in favour of induction of regulatory T cells and/or immune deviation
toward a T helper cell Type 1 phenotype, with resulting inhibition of downstream effector pathways and
induction of immunoglobulin G-associated blocking antibodies. Two main application forms are used
in clinical practice: subcutaneous immunotherapy and sublingual immunotherapy. The advantage of
subcutaneous immunotherapy is its proven efficacy over a broad range of indications. Disadvantages
are systemic allergic reactions and inconvenience for the patient due to frequent doctor visits.
Sublingual immunotherapy has been shown to result in less systemic allergic reactions and may be
more convenient due to home application; however, efficacy has only been proven for allergic rhinitis.
For clinicians, the adherence to practice guidelines and thorough knowledge of allergen products,
application routes, indications, immunomodulatory mechanisms, efficacy, safety, and cost-effectiveness
is important for successful treatment and will be addressed in this review article.
|
|---|
