Sustained unresponsiveness development in wheat oral immunotherapy: predictive factors and flexible regimen in the maintenance phase

Summary

Background and aim. Immunotherapy may induce sustained unresponsiveness (SU) in which the patient can tolerate the allergen without any severe symptoms after discontinuing immunotherapy. The present study evaluated serum and cutaneous markers for predicting SU in patients with wheat anaphylaxis who underwent oral immunotherapy. Moreover, we investigated the effectiveness of a flexible regimen of 5 to 10 g wheat protein (WP) in the maintenance phase of oral immunotherapy (OIT). Methods. This study was conducted on 19 patients with wheat anaphylaxis who underwent OIT. The result of the skin prick test (SPT), besides specific serum IgE (sIgE) and IgG4 (sIgG4) to WP, were evaluated before the desensitization. The maintenance dose started from the preferred dose of 5 to 10 g WP after the build-up phase, if the patient could tolerate it. All patients were recruited 7 to 9 months after undergoing this flexible regimen, and the results of SPT and sIgE, and sIgG4 levels were obtained once more. The patients underwent oral food challenge (OFC) after a 3-4-week avoidance to evaluate SU. Results. There was an association between mean IgE reduction and SU (p less than 0.0006), while no association was observed between the mean increase in specific IgG4 (p = 0.1) and the mean wheal diameter decrease (p = 0.29). In the present study, a 50% reduction in sIgE was associated with SU. Thirteen patients were considered to have a SU. Moreover, there was no association between the flexible regimen and the desensitization rate. Conclusions. The results revealed that the reduction of 50% sIgE is a predictive factor for SU in patients with IgE-mediated wheat allergy.