Scientific Study

 

Background: Oral immunotherapy (OIT) is a treatment option for patients with milk, egg and peanut allergy, but data on the efficacy and safety of cashew OIT is limited. Methods: A cohort of 50 cashew-allergic patients aged ≥4 years, who were consecutively enrolled into cashew OIT (target dose 4000 mg protein) between 4/2016-12/2019. Fifteen cashew-allergic patients who continued cashew elimination served as observational controls. Co-allergy to pistachio and walnut was determined. Full desensitization rate and associated immunological changes in both groups were compared. Patients fully desensitized to cashew were instructed to consume a dose of 1200 mg protein cashew for 6 months and were then challenged to a full dose. Patients with co-allergy to pistachio or walnut were challenged to the respective nut. Results: 44 of 50 OIT-treated patients (88%) compared to 0% in controls, tolerated a dose of 4000 mg cashew protein at the end of the study (odds ratio 8.3, 95% CI 3.9 - 17.7, p<0.001). An additional 3 patients were desensitized to 1200 mg cashew protein and 3 patients stopped treatment. Three patients (6%) were treated with injectable epinephrine for home reactions. Desensitized patients had decreased SPT, sIgE, basophil reactivity and increased sIgG4, following treatment. Following cashew desensitization, all pistachio (n=35) and 4 of 8 walnut co-allergic patients were cross-desensitized to the respective nut. All (n=44) patients consuming a low cashew dose for ≥6 months following desensitization, passed a full dose cashew OFC. Conclusions: Cashew OIT desensitizes most cashew allergic patients and cross-desensitizes to pistachio. Safety is similar to OIT for other foods. https://doi.org/10.1111/all.15212