Oral immunotherapy for sesame allergy: promising results
Published online: May 28, 2019
Sesame allergy is a life-threatening food allergy affecting 0.2-0.8% of the Western world. Given its increasing use in the Western diet, sesame avoidance has become challenging, and the risk of accidental exposure has increased. In fact, the FDA is considering including sesame in allergen labeling laws. There are multiple studies on the use of desensitization to food allergens by Oral Immunotherapy (OIT), the process of administering gradually increasing amounts of the food under medical supervision over weeks and months. However, information regarding OIT for sesame is lacking.
In a paper recently published in The Journal of Allergy and Clinical Immunology: In Practice, Nachshon et al report the course and outcome of 60 sesame OIT-treated patients and compare the outcomes to 15 observational controls all treated at the Institute of Allergy, Immunology and Pediatric Pulmonology at Shamir Medical Center, Zerifin, Israel. The goal of treatment was to gradually desensitize patients to a dose of 4000 mg sesame-protein, (equivalent to 17 grams of Tahini). In order to maintain long-term adherence to sesame OIT, patients who achieved the target dose were instructed to consume a daily maintenance dose of only 1200 mg sesame protein (5 grams of Tahini). Blood was obtained from randomly selected patients from both groups and analyzed for markers of sesame allergy (skin prick test (SPT) wheal size, basophil reactivity, and levels of antibodies promoting (IgE) and inhibiting (IgG4) allergic responses to sesame) at the beginning and at the end of the study.
Fifty-three of the 60 OIT-treated patients (88.3%) could tolerate 4000 mg sesame protein after a median duration of 6.5 months (IQR, 3.8 -12.8 months) compared to none in the observational control group. Adverse reactions occurred in 127/2,720 (4.7%) of doses given in clinic and in 253/13,170 (2%) of home doses. Reactions requiring epinephrine occurred in 10 patients (16.7%) in clinic and in 5 patients (8.3%) at home. All measures of sesame allergy (SPT wheal size, basophil reactivity and IgE antibodies) decreased while the protective IgG4 increased in OIT-treated patients but not in controls. All 46 patients who attended follow-up evaluations more than 6 months after reaching 4000 mg sesame protein, and while consuming a regular dose of 1200 mg, still tolerated a dose of 4000 mg sesame protein. No reactions requiring epinephrine were reported during follow-up. The authors concluded that sesame-OIT is an effective alternative to sesame avoidance in allergic patients. They caution that the potential for adverse events necessitates its performance in specialized centers.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.