Treatment Difficulties in Wheat Oral Immunotherapy and the Predictive Value of Wheat-Specific IgE.

BACKGROUND: Factors associated with wheat oral immunotherapy (OIT) difficulties in patients with IgE-mediated wheat allergy have not been well studied. OBJECTIVE: We aimed to assess factors associated with difficulties in wheat OIT. METHODS: We retrospectively collected data from children under 18 years of age with history of IgE-mediated wheat allergy who underwent wheat OIT. The initial specific IgE (sIgE) of wheat and omega-5-gliadin, wheat skin prick test (SPT) sizes, eliciting doses, and adverse reactions during the OIT were evaluated. RESULTS: A total of 81 children were enrolled, with a mean age of 7.0 ± 2.7 years at the initiation of wheat OIT. The median follow-up duration was 2 years (IQR 1.2 -3.0 years). Difficulties in wheat OIT included patients who experienced frequent reactions (at least grade 2 or exercise-induced reactions) or deviated from the up-dosing protocol, which we defined as 'Complicated cases.' Twenty-six patients (32.1%) were complicated cases. Initial wheat-sIgEs were significantly higher in complicated cases than in noncomplicated cases (median of 192.3 kUA/L (IQR 30.4-590.0) vs 6.9 kUA/L (IQR 1.9-100.0) (p = 0.001)). Initial omega-5-gliadin-sIgEs in the complicated group were also significantly higher, with a median of 15.0 kUA/L (IQR 6.3-69.8) vs 1.6 kUA/L (IQR 0.2-11.4) (p < 0.001). The risk factors for complicated cases include higher omega-5-gliadin-sIgEs and anaphylaxis during the oral food challenge test (aOR 1.035 and 5.684, respectively). CONCLUSION: The initial wheat and omega-5-gliadin-sIgEs were significant risk factors for complicated OIT patients and could be used to monitor these patients carefully during the OIT period.

Children with wheat anaphylaxis and with low wheat specific IgE have a different IgE immunoblot pattern than those with high wheat specific IgE.

BACKGROUND: Children with wheat anaphylaxis can present with a wide range of wheat-specific IgE (sIgE). OBJECTIVE: To identify differences in clinical features and predominant wheat allergens sensitized by these patients. METHODS: Children with history of wheat anaphylaxis were recruited. Skin prick test (SPT) to wheat, sIgE to wheat, omega-5 gliadin (ω5G), lipid transfer protein (LTP) were investigated. Profiles of IgE-bound wheat allergens were studied to identify predominant wheat allergens. RESULTS: Twenty-nine children (17 males) aged 1-18 years were enrolled. Sixteen patients (55.2%) had wheat-sIgE > 100 kUA/L (WAhi) and 13 patients (44.8%) had wheat-sIgE < 34 kUA/L (WAlo). The median of peak wheat-sIgE in WAhi and WAlo were 340.5 kUA/L (IQR 184.3, 564.5) and 12.2 kUA/L (IQR 1.4, 41.3), respectively. Oral food challenge test (OFC) was carried out in 12 of 13 patients in the WAlo group, all of which had positive results. Eight of these 12 patients developed anaphylaxis during OFC despite having wheat-sIgE less than 10 kUA/L. There were no differences in clinical characteristics and atopic history between WAhi vs. WAlo. Medium to low molecular weight gliadin (< 40 kDa) and glutenin (< 60 kDa) were commonly recognized by patients with WAhi. IgE immunoblot pattern among the WAlo group was more widely dispersed than those with WAhi. CONCLUSIONS: Wheat anaphylaxis can occur in patients with low wheat-sIgE. Predominant wheat allergens recognized by patients with WAlo were different than those with WAhi. Such difference could be responsible for anaphylaxis at even low levels of wheat-sIgE.

Feasibility of a 3-step protocol of wheat oral immunotherapy in children with severe wheat allergy.

BACKGROUND: Wheat allergy is not an uncommon event among Thai children. Despite strict avoidance, some patients developed reactions after accidental exposure to minute amount of wheat and thus disturbed their quality of life. Wheat oral immunotherapy (OIT) has been reported to be an alternative treatment for such patients. OBJECTIVE: We designed a new 3-step wheat OIT protocol for treatment of severe wheat allergy in Thai patients. The feasibility of the protocol is evaluated and is reported here in this paper. METHODS: We retrospectively reviewed medical records of 26 patients who had undergone wheat OIT during a 30-month period. The 3-step protocol consisted of an initial phase of double-blind, placebo-controlled food challenge (DBPCFC) and initiation of OIT, a build-up phase, and a maintenance phase. Patient retention in the protocol was the main outcome for this feasibility study. Adverse effects during OIT were recorded. Correlation between serum specific IgE (SpIgE) to wheat and eliciting dose in phase I was determined. RESULTS: Fourteen females and 12 males with a median age of 6 years were studied. Their median age when wheat allergy began was 8 months. Median SpIgE to wheat was high (198 kUA/L). All patients developed reactions during DBPCFC with 17 of 26 patients had moderate to severe reactions required adrenaline injections. Median of eliciting dose of wheat was exceedingly low, i.e., 20 mg of wheat protein. At the end of the study, 23 of 26 patients (88%) were still in the study. Adverse reactions during the build-up phase was frequent (13 patients, 50%), with adrenaline required in 6 occasions. Six patients reached maintenance phase. CONCLUSION: The new 3-step wheat OIT protocol was feasible in these highly wheat-sensitized patients. Despite a high retention rate, a high rate of adverse effects was observed both during DBPCFC and build-up phases.