Oral Desensitization to Wheat in School Aged Children

University of Oulu, Oulu University Hospital, Tampere University Hospital, Kuopio University Hospital

The aim of the study is to induce tolerance to wheat in wheat allergic children via oral desensitization therapy. The hypothesis is that oral administration of wheat with increasing dosing will increase the individual threshold for allergic reactivity to wheat protein (i.e. desensitization) and even result in no reactivity (i.e. full tolerance). Along with this, the risk for severe allergic reaction to wheat protein is minimized and the diet of patients can partly or completely be normalized. In addition to clinical measures, the immunological mechanisms of desensitization therapy are studied in detail at cellular and molecular level.

This is a prospective multicenter study investigating the efficacy, safety and immunological mechanisms of oral wheat desensitization therapy in school-aged (6-16 yrs of age) wheat allergic children. Wheat allergic children with avoidance diet, immediate reaction in a recent (less than 4 months) food challenge test for wheat and elevated serum wheat-specific IgE levels are recruited to the study. Patients having uncontrolled asthma, other lung disease, cardiovascular disease or other significant systemic disease and patients having poor compliance are excluded. Well-cooked wheat spaghetti is given daily to the patients starting from a minimal dosage (0,0003 g of wheat protein) and increasing the dosing in every 1-2 weeks until a dosage corresponding the size of one meal. The initial dosage is given and certain defined dosage step-ups are carried out in the hospital outpatient clinic. The patient and parents are prepared for the emergency treatment of severe allergic reaction and carry adequate medication with them. The daily use of spaghetti continues with the received maintenance dosage for additional 3 months, until the clinical evaluation of the patient. Thereafter, the patients are allowed to use also other wheat products. Peripheral venous blood samples are taken before therapy and at 3 months and 1 year follow-up visits after reaching the maintenance dosage. The characteristics and function of isolated peripheral blood mononuclear cells (PBMC) will be specifically tested using flow cytometric methods. The expression levels of cell-specific mRNAs (messenger ribonucleic acid) and cytokines are measured with qRT-PCR (quantitative reverse transcriptase real-time polymerase chain reaction)and flow cytometry based methods. In addition, specific IgE (immunoglobulin E) levels are measured and serum samples are frozen for further testing. Two separate control groups are also recruited. The first group includes patients with previous food-challenge proven IgE-mediated wheat allergy with spontaneous recovery and the current free use of wheat protein in their diet. The second group includes children (6-16 yrs of age) who come to hospital for a minor surgical operation (e.g. minor trauma, circumcision, patellar luxation etc.). Children with asthma, allergy, atopic eczema, any other chronic disease or recent infection (less than 2 weeks ago) are excluded from this group. Peripheral venous blood samples are taken from all control children. The characteristics and function of isolated PBMCs, the expression levels of cell-specific mRNAs and cytokines and specific IgE levels are measured.

Well-cooked wheat spaghetti is given daily to the patients starting from a minimal dosage (0,0003 g of wheat protein) and increasing the dosing in every 1-2 weeks until a dosage corresponding the size of one meal.

Change in the tolerance to wheat and the amount of daily use of wheat in 3 months after the 5 months oral desensitization therapy.

Change in the tolerance to wheat and the amount of daily use of wheat in 1 year after the 5 months oral desensitization therapy.

Number of participants with adverse events as a measure of tolerability and safety at 3 months after the 5 months desensitization therapy

Number of participants with adverse events as a measure of tolerability and safety at 1 year after the 5 months desensitization therapy

Flow cytometric characterization of the change in the proportions of various T cell subtypes and in the function of these cells in in vitro proliferation and suppression tests between the samples taken before the treatment and 3 and 12 months after the treatment.

qRT-PCR measurement of the change in the expression level of T cell subtype specific mRNA levels between the samples taken before the treatment and 3 and 12 months after the treatment.

Flow cytometric measurement of the change in the levels of T cell subtype specific cytokine levels between the samples taken before the treatment and 3 and 12 months after the treatment.

Inclusion Criteria: Elevated serum wheat specific IgE Immediate reaction in open oral wheat challenge test Diet free from wheat, rye, and barley Exclusion Criteria: Uncontrolled asthma Other lung disease Cardiovascular disease or other significant systemic disease Patients having poor compliance