Salivary biomarkers as an indicator for allergic reactions during oral food challenges in children

There is increasing attention for improvement of diagnosing food allergy. Until now, the double-blind placebo controlled food challenge (DBPCFC) is seen as the gold standard to establish or exclude the diagnosis of food allergy. The reported symptoms are used to conclude whether the food challenge was positive (i.e. food allergy confirmed), negative or inconclusive. It can be difficult to draw firm conclusions especially if subjective symptoms such as abdominal discomfort occur or if adverse reactions take place during placebo administration. Furthermore, the DBPCFC conclusion is subject to individual interpretation. Due to these limitations, it would be valuable to have additional objective criteria or biomarkers available to interpret the induced symptoms.

To study biomarkers associated with allergic reactions in children, it will be desirable to use noninvasive diagnostic methods, especially if serial assessments are needed. Salivary biomarkers could improve the diagnostic process of food allergy, yet results are still conflicting. Ideally, the potential release of specific allergic mediators can be used to determine objectively whether one has an allergy or not. Therefore, we aim to investigate the association between the occurrence of symptoms during DBPCFC and biomarkers in saliva.

We hypothesise that during the food challenge, a quick and dose dependent increase in mast cell markers may occur, which will not happen at the placebo day.

Prior to, during and following DBPCFC, saliva will be collected. The minimum amount of saliva samples collected from each child is seven and the expected maximum is fourteen samples. Samples will be collected at both food challenge days (placebo and verum) in a time period of several hours depending whether symptoms develop or not.