Combination of diagnostic tests enables optimisation of resources and improved patient outcomes
allergic, allergy
ALLERGY, BEST, EGG ALLERGY
Using 100% sensitivity and 100% specificity cut‐offs to identify non‐allergic and allergic children, respectively, and equivocal cases as the ones falling between cut‐offs, whom will need further testing and ultimately OFC to confirm the allergic status, avoids false‐positives and false‐negatives, resulting in 100% accuracy. Applying this approach to single tests followed by OFC, BAT was the test that significantly reduced the number of OFC (Table Number of oral food challenges to baked egg required with individual tests using positive and negative cut‐offs.
Abbreviations: BAT, basophil activation test; EW, egg white; NA, non‐allergic; OFC, oral food challenge; sIgE, specific IgE; SPT, skin prick test.Sequential use of diagnostic tests to predict the outcome of challenges to baked egg with the basophil activation test (BAT) as a second step in the diagnostic process, after specific IgE to egg white (sIgE EW) or specific IgE to ovalbumin (sIgE OVA). Cut‐offs with 100% specificity (i.e. 44.7 KU/L for sIgE EW; 21.1 KU/L for sIgE OVA; 48.8% CD63+ basophils for BAT for children of all ages; and 5.35 KU/L for sIgE EW and 65.5% CD63+ basophils for BAT for children younger than 2 years) were used to confirm baked egg allergy (BEA); Cut‐offs with 100% sensitivity (i.e. 0.19 KU/L for sIgE EW; 0.21 KU/L for sIgE OVA; 2.2% CD63+ basophils for BAT for children of all ages; and 0.17 KU/L for sIgE EW and 2.3% CD63+ basophils for BAT for children younger than 2 years) were used to exclude allergy (NA, non‐allergic). Patients with results between these two cut‐offs would need an additional test (BAT) or an OFC—after OFC, patients were considered allergic or non‐allergic depending on the OFC outcome, positive or negative, respectively. Best combinations of tests for all ages and younger than 2 years age group are shown. This approach resulted in 100% accuracy.