Published Online: February 10, 2015
Diagnosis of suspected food allergies can be challenging when evidence of clinical reactivity is unclear, for example, when patients are avoiding foods or have yet to be exposed. Lab testing for IgE by skin prick or serum antibody tests can yield “false positive” results in up to 50% of cases. This is because many individuals that test positive (sensitized individuals) are not really allergic. Confirmatory testing by oral food challenge is often required to make a definitive diagnosis. Food challenges can be expensive and time consuming, and, for these reasons, may often not be performed.
In a recent article in The Journal of Allergy and Clinical Immunology (JACI), Martino et al studied DNA methylation in blood samples from children undergoing lab testing and oral food challenges. By screening 450,000 methylation sites in children with true clinical allergy, and those who were sensitized but tolerant, they identify methylation sites that in combination could be used to predict food allergy.
The study showed that methylation biomarkers outperformed IgE and skin prick tests for the task of predicting food allergy. In two different patient groups, the authors were able to accurately predict oral food challenge outcome. The study describes how targeting these biomarkers could complement the existing suite of diagnostic tools to aid clinical decision-making in the management of food allergy.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.