Oral Immunotherapy for Food Allergic Patients

With the advent of spring, we are happy to present another report from the Center for Allergy at Assaf HaRofeh. As described in previous updates, a major focus over the past year has been the inception of our comprehensive treenut allergy diagnosis and treatment project. This project is unique in its aim and scope, and has been a focus of interest within the broad clinical allergy community. The annual meeting of the American Academy of Allergy Asthma & Immunology held this past March in Atlanta, GA gave us the opportunity to present our work.

In one presentation, we described our findings regarding the incidence of different treenut allergies. A major complicating factor in food allergy diagnosis is that patients can often react to a specific nut in a skin sensitivity test (in which the allergen is applied topically), but still be able to consume it safely. We found this to be the case for the panel of treenuts we tested. In fact, for some nuts, fewer than half of the patients who had positive skin tests were truly allergic to them.  We also looked at treenut allergy co-incidence and reported that pistachio and pecan allergy predicts a very high probability for cashew and walnut allergy, respectively. These results  should prove useful for optimization of treenut allergy testing protocols.

In a second presentation, we reported on our use of the basophil activation test (known as "BAT") in diagnosing treenut allergy. As described above, skin sensitivity to a given treenut does not always indicate a true food allergy. While oral food challenges are the gold standard for food allergy diagnosis, they can be costly and intimidating for patients. The BAT is a blood test which assesses the reaction of white blood cells, known as basophils, to potential allergens. Basophils are cells which release histamine and other mediators during allergic reactions, so their reactivity to allergens in a blood test might be a good indicator of true food allergy. We performed BAT on blood from patients with different treenut allergies, and found that in the case of walnut and pistachio, BAT could be used in conjunction with the skin sensitivity test to accurately predict food allergy. For these nuts, the number of necessary oral food challenges could be reduced by 50%. 

Your support allows us to proceed in our work to improve food allergy diagnosis and treatment, particularly in complex arenas such as treenut allergy.