Sublingual immunotherapy for food allergy
Sublingual immunotherapy (SLIT) is a form of immunotherapy that involves placing a glycerinated extract or a dissolving tablet under the tongue in order to elicit an immune response to a particular allergen. SLIT has been used for the successful treatment of allergic rhinitis, and may be an effective form of treatment of food allergy. Oral Langerhans cells (oLC’s) play a key role in the efficacy of SLIT by acting as antigen presenting cells when the antigen is placed under the tongue and absorbed into the oral mucosa. During most treatment protocols of SLIT, subjects receive a daily dose of SLIT followed by biweekly dose escalations in a supervised setting up to a maintenance dose. SLIT has been studied for allergy to peanut, cow’s milk, hazelnut, kiwi and peach and has shown to increase the maximum cumulative tolerated dose of the food compared to placebo. SLIT studies have shown increases in food-specific IgG4, and initial increase in food-specific IgE followed by a later decline in food-specific IgE. The magnitude of desensitization to the target food is not as great in SLIT as in OIT, however SLIT is better tolerated than OIT with fewer side effects, fewer allergic reactions and anaphylaxis to treatment doses. There are fewer withdrawals from treatment due to adverse effects in SLIT compared to OIT. While these data have led to early trials of industry-sponsored commercial peanut SLIT products, the potential for SLIT to induce lasting tolerance remains an important area for continued studies.
