Usefulness of Gly m 4-specific IgE test in the diagnosis of Rosaceae fruit-oral allergy syndrome caused by Betulaceae pollen sensitization

Abstract

Background: Pollen-food allergy syndrome (PFAS) is caused by the cross-reaction of the specific IgE to pollen allergens with similar allergens contained in fruits, vegetable, and nuts. The representative allergen responsible for this cross-reaction is pathogenesis-related protein (PR)-10. Specific IgE test using Gly m 4, soybean PR-10, is widely used to diagnose soy allergy. We aimed to investigate whether the Gly m 4-specific IgE test is useful for predicting oral allergy symptoms (OAS) to Rosaceae fruits in PFAS caused by Betulaceae pollen sensitization. Methods: Forty-one patients with suspected PFAS were enrolled. Specific IgE levels were measured against alder pollen, apple, peach, pear, and Gly m 4, and correlation between test results and allergic symptoms was assessed to compare the accuracy of these allergen-specific IgE tests. Results: Of the 41 patients, 32 were positive for alder pollen-specific IgE. Of those, 16 showed OAS to at least one of apple, peach, and pear (OAS (+) group), and the rest 16 cases showed no symptoms (OAS (−) group). The Gly m 4-specific IgE value was significantly higher in the OAS (+) group (p =.014), and the highest in area under the receiver operating characteristics curve. The cut-off value for detection of the OAS (+) group was 2.65 UA/ml, with a sensitivity of 62.5% and a specificity of 81.3%. Other allergen-specific IgE values were not significantly different between the two groups. Conclusions: In the subjects sensitized to Betulaceae pollen allergens, the Gly m 4-specific IgE test is useful for predicting OAS of Rosaceae fruits.