Clinical characterization of study population.
This investigation included patient samples from the Toronto site of MONAS with confirmed allergy status regarding peanut allergy and available serum samples. In the total of 96 serum samples 69 were classified as peanut allergic (PA) and 27 as non-allergic controls (NA) based on positive OFC, or a pre-test probability of >90% allergic reaction (Fig. 1a ). Amongst those samples, SPT as well as sIgE measurements were readily available from 47 and 67 patients, respectively (Fig. 1a-b and Table S1 ). PA and NA differed significantly regarding SPT wheal size (Fig. 1b ) and sIgE serum levels against whole peanut extract or the seed storage proteins Ara h 1 and Ara h 2 (Fig. 1c ). Additionally, the performance of SPT and sIgE measurements to correctly identify the allergic status was assessed using receiver-operating characteristic (ROC) curves. Based on the calculated optimal cut offs for each allergen, the diagnostic accuracy was highest for IgE against Ara h2 with an area under the ROC curve (AUROC) of 0.91, which outperformed both sIgE measurement against whole peanut extract and SPT with peanut extract (both AUROC of 0.89) (Table S2 ).