The Basophil Activation Test Is the Most Accurate Test in Predicting Allergic Reactions to Baked and Fresh Cow's Milk During Oral Food Challenges.

BACKGROUND

Cow's milk is the most common cause of food allergy and related fatalities. Consumption of baked milk (BM) has been associated with better prognosis, nutrition and quality-of-life.

METHODS

The BAT 2 milk study (NCT03309488) was a diagnostic study of cow's milk allergy designed according to STARD guidelines. All children had an oral food challenge (OFC) to BM, and those who tolerated BM were offered an OFC to fresh milk (FM). The diagnostic performance of the basophil activation test (BAT), skin prick test (SPT) and specific IgE (sIgE) was assessed in comparison with OFC.

RESULTS

Out of the 150 children studied, 85% tolerated BM and 56% also tolerated FM. BAT had the best diagnostic accuracy (area under the receiver operator characteristic curve 0.90 for BM and 0.81 for FM) compared with the other tests for both BM (sIgE: 0.79 and SPT: 0.70) and FM (sIgE: 0.74 and SPT: 0.78) allergies. Using 100% sensitivity and 100% specificity cut-offs to select patients for OFC would have led to the following proportion of children having OFC (and positive OFC) to BM: 99% (13%) for SPT to baked milk, 82% (17%) for sIgE to boiled milk, and 49% (24%) for BAT to baked milk. In children younger than 2 years, only 27% required an OFC following BAT to BM (compared to 100% and 81% following SPT or sIgE to milk extract, respectively), with 100% diagnostic accuracy.

CONCLUSIONS

BAT was the best test to identify children who reacted on OFC to BM or FM. Using 100% sensitivity and 100% specificity cut-offs, BAT ensured the lowest need for OFC and 100% diagnostic accuracy.

TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT03309488.