Luminex-based Assay to Identify Major IgE-binding Episode Among IgE-mediated Wheat-allergic Patient

Completed

Brief Summary: This study will be using Luminex-based peptide assay (LPA) to determine major IgE-binding epitope among wheat allergic children to differentiate clinical phenotype.

Detailed Description: Luminex-based peptide assay (LPA) is a novel tool using machine learning techniques, developed to predict different degrees of food allergy has been successfully reported among cow's milk protein allergy. This technique provide a more precise and advanced adaptation from microarray-based immunoassay (MIA). Using this technique will aid us for the differentiation of clinical phenotypes of wheat-allergic patients. This study will be the first study to date using this technique aim to determine major IgE-binding epitope among immediated-reaction of wheat allergic children to differentiate clinical phenotypes, and may lead to further study to develop the new therapeutic approach to wheat-allergic patients.

Recruitment & Eligibility

Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Arm && Interventions

Group	Intervention	Description
Wheat oral immunotherapy	Blood drawing	Patients with IgE-mediated wheat allergy and underwent wheat oral immunotherapy for at least 6 months or at the maintenance phase of the treatment
Wheat-allergic	Blood drawing	The diagnosis of IgE-mediated wheat allergy was made if they have one of the following criteria 1. a convincing clinical history of the reactions within 4 hours after wheat ingestion during the past 12 months combined with positive skin prick test (SPT) and/or the level of specific IgE (sIgE) to wheat or 2. a positive oral food challenge (OFC) result to wheat during the past 12 months
Wheat tolerant	Blood drawing	Patients with wheat tolerant confirmed by negative oral food challenge (OFC) result to wheat during the past 12 months

Primary Outcome Measures

Name	Time	Method
Major Immunoglobulin (Ig) E-binding epitope on wheat proteins and serum/plasma of patients	48 months	For Luminex data, the binding intensity of antibody to epitope specific beads was calculated from the florescence signal of each bead. An index score of binding intensity was generated from the log2 transformation of the signal-to-background ratio and each peptide element, which was close to a normal distribution. A plate effect was observed and adjusted for using linear models. Antibody binding intensities (Luminex) from different groups were compared. To assess the changes in epitope-binding profiles, a linear model was used with group as a factor. Comparisons of interests were tested using t tests and resultant P-values were adjusted for multiple hypotheses using the Benjamini-Hochberg approach, which controls the false discovery rate (FDR) across epitopes. Epitopes were defined as differentially binding epitopes (DBE) if the FDR \< 0.05 and fold changes (FCH) \> 1.5.

Secondary Outcome Measures

Name	Time	Method
Predict different severity of wheat hypersensitivity reaction	48 months	For Luminex data, the binding intensity of antibody to epitope specific beads was calculated from the florescence signal of each bead. An index score of binding intensity was generated from the log2 transformation of the signal-to-background ratio and each peptide element, which was close to a normal distribution. A plate effect was observed and adjusted for using linear models. Antibody binding intensities (Luminex) from different groups were compared. To assess the changes in epitope-binding profiles, a linear model was used with group as a factor. Comparisons of interests were tested using t tests and resultant P-values were adjusted for multiple hypotheses using the Benjamini-Hochberg approach, which controls the false discovery rate (FDR) across epitopes. Epitopes were defined as differentially binding epitopes (DBE) if the FDR \< 0.05 and fold changes (FCH) \> 1.5.