Allergen Immunotherapy: How does it work?
Immunotherapy, or the treatment of disease via immune response, is used to treat a number of diseases ranging from cancer to autoimmune disorders.
Immunotherapy procedures are designed to either activate or suppress a specific immune response using a combination of monoclonal antibodies, cytokines, chemokines, and even helminths (e.g., the use of tapeworms to suppress ulcerative colitis and Crohn’s Disease). In the case of cancer, for example, cell-based immunotherapy can be used to stimulate the activity of lymphocytes, macrophages, and natural killer cells that target cancerous cells.
Unsurprisingly, immunotherapy can also be used to treat allergies.
What Allergies Are Candidates for Treatment?
Your allergies are caused by a defensive, inflammatory reaction on the part of your immune system to the presence of specific allergens. Common allergens that produce noticeable allergic reactions in susceptible individuals include dust, pollen, and animal dander, but individuals with one or more of these allergies could also have a number of unknown allergies that do not manifest in a noticeable way.
In other words, there are gradations of allergies, and some are so minor that you may not even know you have them. But those allergies are also non-disruptive and probably don’t need to be treated. Only the allergies that seriously disrupt or impair your ability to go about your day should be candidates for allergen immunotherapy.
Additionally, not all allergies are created equal. Allergen immunotherapy is known to work for patients suffering from allergic rhinitis, allergic conjunctivitis, or allergic asthma1-4 caused by pollen, dust mites, cat dander, cockroaches, fungi, and Hymenoptera venom (i.e., bee and wasp stings)3-8. Allergy immunotherapy is not effective for atopic dermatitis or urticaria, and is not recommended for food allergies due to the high risk of anaphylaxis.
What is Allergen Immunotherapy?
Allergen immunotherapy is simple in practice. By applying a measured amount of the allergen in question either sublingually (under the tongue) or subcutaneously (injected beneath the skin), a patient’s immune response can be slowly modified, via natural activation immunotherapy, to tolerate the allergen in question and produce diminished allergic responses. Immunotherapy sessions take place under the care and supervision of a healthcare professional with anaphylaxis training. Patients are monitored for 20-30 minutes after an injection.
Subcutaneous allergen immunotherapy was first practiced in 1911, and has since been used to treat millions of people suffering from allergies around the world. It is an effective treatment because, unlike over-the-counter or prescription allergy medications, allergen immunotherapy treats both the symptoms of the allergy as well as the cause.
In order to determine whether a patient qualifies for allergen immunotherapy, a brief and IgE-mediated type 1 hypersensitivity skin test is performed. A positive skin test reaction indicates the presence of allergen-specific IgE antibodies and defines the nature and intensity of the allergic reaction. For the purposes of determining candidate suitability, skin tests are faster and more accurate than in vitro blood tests.
Once the physician identifies allergic triggers, the specific treatment regimen is decided upon. Typical allergen immunotherapies occur once a week for up to 30 weeks, then once every two weeks, and eventually once every four weeks. Altogether, a typical allergen immunotherapy treatment can last anywhere from three to five years. But the benefits, especially in the case of the successful treatment of asthma, can last a lifetime.
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2. Adkinson NF Jr, Eggleston PA, Eney D, Goldstein EO, Schuberth KC, Bacon JR, et al. A controlled trial of immunotherapy for asthma in allergic children. N Engl J Med. 1997;336:324–31.
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