Utility of the peripheral blood basophil histamine release test in the diagnosis of hen's egg, cow's milk, and wheat allergy in children.

BACKGROUND: The diagnosis of food allergy (FA) is made by oral food challenge tests (OFCs) that occasionally produce serious symptoms in patients; therefore, whether to perform OFCs should be carefully considered. The utility of the histamine release test (HRT) in the diagnosis of childhood FA has not been fully examined.

METHODS: Sixty-four subjects with suspected hen's egg allergy, cow's milk allergy (CMA), and wheat allergy (WA) were enrolled. The diagnosis of FA was made based on the outcomes of OFCs or a convincing history of symptoms after food ingestion within 6 months before or after sample collection. HRT was performed using an HRT Shionogi kit. The threshold of histamine release (HRT threshold), which was defined as the minimum concentration of food antigen to induce a 10% net histamine release, was analyzed in association with FA diagnosis.

RESULTS: Receiver operating characteristic analysis showed that the HRT threshold was useful in the diagnosis of heated egg allergy (HEA), raw egg allergy (REA), CMA, and WA. We were able to determine the cutoff value for the HRT threshold in relation to outcomes of OFCs. The cutoff value was 6 ng/ml of egg white antigen in HEA and REA (p < 0.01), 40 ng/ml of milk antigen in CMA (p < 0.01), and 500 ng/ml of wheat antigen in WA (p < 0.05). The efficiency was 70.3% for HEA, 78.0% for REA, 77.6% for CMA, and 70.7% for WA.

CONCLUSIONS: We conclude that the HRT threshold measurement for egg white, milk, and wheat antigen is related to outcomes of OFCs and is useful in determining when OFCs should be performed.