An Observational Study of Childhood Food Allergy

Study Overview
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Brief Summary
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The purpose of this study is to observe the natural course of food allergy, including both the development of peanut allergy in infants at high risk for developing this allergy, and the resolution of both egg and cow's milk allergy.

Detailed Description
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This observational study will investigate the developmental immunology of peanut, egg, and milk allergy in a cohort of milk- or egg-allergic children who are at risk for peanut allergy. This strategy will help to delineate, compare, and contrast biological markers and immunologic changes associated with the development of peanut allergy and loss of egg and milk allergy, while simultaneously evaluating important clinical and environmental influences likely to account for the recent rise in the prevalence of these allergies. The hallmark of food-allergic disease is the production of food-specific Immunoglobulin E (IgE) antibodies that represent an end result of a T helper 2 (Th2) influenced immune response. Currently, there is only a limited understanding of the mechanisms involved in the developmental course of food allergies. To effectively prevent or reverse the progression of food allergy, immune interventions will be needed. Furthermore, it is likely that successful strategies will need to be directed to those persons at identifiable risk (e.g., who have biomarkers associated with development of peanut allergy).

Official Title
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A Prospective Cohort Study of Immune Mechanisms, Genetic Factors, and Clinical and Environmental Characteristics Associated With the Occurrence and Clinical Outcome of Food Allergy (CoFAR2)

Conditions
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Food Hypersensitivity, Peanut Hypersensitivity, Egg Hypersensitivity, Milk Hypersensitivity

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria for Children with Food Allergy: Participants who meet all of the following criteria are eligible for enrollment as study participants: Atopic dermatitis evaluation Either A convincing clinical history of cow's milk (and/or egg) allergy and a positive prick skin test (≥ 3mm larger than the negative control) to cow's milk (and/or egg, if egg allergy history), or Moderate to severe atopic dermatitis at the time of enrollment (or by a history prior to removal of milk and/or egg from the maternal (if breastfed) or infant diet) and a positive prick skin test to milk or egg, or Positive oral food challenge, prior to study entry, to either milk or egg with positive skin test Written informed consent from parent/guardian Willing to submit specimen for central laboratory plasma peanut IgE Exclusion Criteria for Children with Food Allergy: Participants who meet any of these criteria are not eligible for enrollment as study participants: Chronic disease (other than asthma, atopic dermatitis, rhinitis) requiring therapy (e.g., heart disease, diabetes) Participation in an interventional study* Inability to discontinue antihistamines for routine tests Children (other than sibling controls) from families with one child already participating in the observational study Confirmed or convincing evidence of peanut allergy Sibling Inclusion Criteria for Mechanistic Studies: No history of food allergy (unrestricted diet), asthma, atopic dermatitis, allergic rhinitis (for blood sample) Full sibling of child enrolled in study Signed informed consent/assent as applicable Sibling Exclusion Criteria in Mechanistic Studies: Not fulfilling inclusion criteria History of chronic anemia Disease or medication that impair immune responses Sibling Inclusion Criteria for Genetic Testing: Full sibling of child enrolled in study Signed informed consent/assent as applicable Sibling Exclusion Criteria for Genetic Testing: Not fulfilling inclusion criteria

Ages Eligible for Study
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Minimum Age: 3 Months
Maximum Age: 15 Months

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Children with food allergy<br>340 longitudinally followed children with egg and/or milk allergy without elevated peanut specific Immunoglobulin E (IgE), less than 5 kUA/L | |
| Full sibling controls for genetic studies<br>Approximately 250 not age matched full siblings (i.e., non-step siblings, non-half siblings) will be recruited as an additional control group for genetic studies. | |
| Full sibling controls for mechanistic studies<br>Approximately 50 not age matched full siblings (i.e., non-step siblings, non-half siblings) will be recruited as an additional control group for mechanistic studies. A subset of this cohort will be without food allergy, | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Peanut allergy after the age of three years | diagnosed by generally accepted, > 95% accurate, clinical criteria such as oral food challenge. | Year 10 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Resolution of milk allergy after the age of three years | determined by well established criteria with > 95% diagnostic accuracy. Additional (interval analysis) endpoints of egg and milk allergy will be explored in younger children because these allergies may resolve earlier. Common clinical allergy evaluations (e.g., prick skin tests and food-specific IgE antibodies to the 3 targeted foods and common environmental allergens) will be performed and incorporated in the diagnoses of food allergy and atopy. | Year 10 | 
| Resolution of egg allergy after the age of three years | determined by well established criteria with > 95% diagnostic accuracy. | Year 10 | 
| Resolution of peanut allergy after the age of three years | determined by well established criteria with > 95% diagnostic accuracy. | Year 10 | 
| Resolution of a positive test to peanut after the age of three years (suspected allergy category) | determined by well established criteria with > 95% diagnostic accuracy. | Year 10 | 
| Development/persistence of milk allergy after the age of three years | determined by well established criteria with > 95% diagnostic accuracy. | Year 10 | 
| Development/persistence of egg allergy | determined by well established criteria with > 95% diagnostic accuracy. | Year 10 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Food Allergy