Development of an Algorithm to Better Predict Clinical Responsiveness to Peanut
Recruitment status was: Recruiting
Procedure: allergy skin testing
|Study Design:||Observational Model: Defined Population
Primary Purpose: Screening
Time Perspective: Cross-Sectional
Time Perspective: Prospective
|Official Title:||Molecular Analysis of Immuno-Regulatory Genes Expressed by Mononuclear Cells From Peanut Skin Test Positive Individuals With and Without a History of Peanut Ingestion|
|Study Start Date:||September 2002|
Peanut allergy occurs in about 1% of the population. Allergic reactions to peanuts and tree nuts account for the majority of fatal and near fatal food allergic reactions. Currently the only available treatment is complete avoidance of peanut. Despite avoidance, the majority of peanut allergic people will accidentally ingest peanut. Accurate diagnosis is critical, yet often problematic. Current diagnostic methods such as skin and blood tests cannot predict definitively who is allergic and can result in patients being falsely labeled. One such group is children who have never been exposed to peanut as a means of preventing allergy, yet have positive skin tests. The only means of definitively diagnosing this group is with an oral peanut challenge, a potentially risky procedure. Previous studies have demonstrated differences in certain genes and growth factors between peanut allergic and non-allergic individuals. The proposed study has 2 phases. The first phase, almost completed, examines expression of genes and growth factors in defined groups of peanut allergic and non-allergic individuals which should help distinguish between these groups. Peripheral blood mononuclear cells from each patient will be cultured and analyzed for a variety of growth factors and other immune molecules, including mRNA, thought to be important in allergy.
The second phase of this study will involve feeding peanut to individuals with positive skin tests, who have never been peanut exposed. Their blood will be examined before and after the challenge using information from Part 1, and results will be correlated with their ability to tolerate peanut on feeding. This study should enable us to better predict who is truly peanut allergic.
There are four groups of patients in this study. Group 1 consists of individuals who are allergic to peanut. This group of individuals will have a positive skin test to peanut and a previous allergi reaction to peanut. Group 2 consists of indivduals who have a positive skin test to peanut but who are able to ingest peanuts without problems. Group 3 consists of individuals who have a positive skin test to peanut but who have no known ingestion of peanut and who have avoided peanut lifelong for whatever reason (e.g. a strong family history of peanut allergy). Lastly, group 4 consists of control subjects who are negative to the peanut skin test and are able to tolerate peanut without problems.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00243555
|Hamilton Health Sciences Corporation, McMaster Site|
|Hamilton, Ontario, Canada, L8N 3Z5|
|Principal Investigator:||Susan Waserman, MSc, MD, FRCPC||Hamilton Health Sciences Corporation, McMaster Site|