METHODS: Urine samples from 17 children undergoing OIT were collected at three points: 4hours after food intake at home for OIT, before OFC (baseline), and 4hours after OFC. All the patients continued to consume low doses of foods for more than 6months and did not experience any allergic reaction on the day of urine collection.
RESULTS: The results of OFC were negative for 8 patients and positive for 9 patients (ages 2-13). The ratios of the cumulative dose of food used for the OFC/daily intake dose of the food for OIT at home were similar between OFC-positive patients and OFC-negative patients, (28.4 and 22.5, respectively; P > 0.05). The mean difference in the tetranor-PGDM concentration between 4hours after food intake at home and the baseline concentration in OFC-positive patients was significantly higher than that in OFC-negative patients (0.95 vs. 0.16 ng/mg CRE, P < 0.05).
CONCLUSIONS: The urinary tetranor-PGDM concentration at 4hours after food intake at home in patients receiving OIT can be used to predict the results of OIT as verified using OFC by detecting the subclinical activation states of mast cells during OIT.