While oral immunotherapy for peanut allergy grabs plenty of headlines, the question is often raised whether the technique will work for tree nuts as well. In a study presented at the AAAAI meeting in March 2016, researchers from the University of Arkansas say they’ve observed that walnut OIT can effectively and safely desensitize patients to significant amounts of the allergen, as well as other tree nuts.
Fourteen patients with a walnut allergy and an allergy to another tree nut were given either walnut OIT or a placebo OIT treatment over 38 weeks. After 38 weeks of treatment, researchers found that those undergoing walnut OIT “demonstrated significant increases in successfully consumed doses” of both walnut and the other tree nut they were allergic to, as compared to initial study food challenges.
The amount of walnut tolerated at the outset of the study was 0.3 grams (the midpoint for the 14 participants). At the conclusion the tolerated dose was 5 grams. For the other tree nuts, the amount tolerated at the study’s outset was 0.3 grams, and the amount at 38 weeks was 3.75 grams (both are the midpoint amounts tolerated by the 14 participants). Researchers noted that their work showed that walnut OIT can lead to “clinical desensitization to both walnut and a test tree nut after 38 weeks on therapy.”
They added that immunologic “changes supporting the development of sustained unresponsiveness [to tree nuts] were observed” in the patients’ post-study tests. Researchers also noted that none of the patients had severe symptoms over the course of the study.