One-hour blood-xylose test in diagnosis of cow's milk protein intolerance.

In this prospective study, 18 consecutive children suspected of cow's milk protein intolerance (C.M.P.I.) on clinical grounds were investigated before and after challenge with cow's milk. One-hour blood-xylose, serum-IgE, eosinophil count, serum-complement (C3) and a jejunal biopsy specimen for histology and disaccharidase activity were obtained from all patients before challenge. Serum-complement was measured again 24 h after the beginning of the challenge and the first three tests were repeated on the fifth day. A second jejunal biopsy was obtained in 9 of the first 10 children. 15 of the 18 children were considered to have C.M.P.I. The one-hour blood-xylose test emerged as a simple and valuable test in the diagnosis of C.M.P.I. A significant drop (51--81%) in the one-hour blood-xylose level was observed in all 15 patients. In all patients but one it dropped below 25 mg/dl. Mean value (+/- S.D.) for the group was 47.5 +/- 11.1 mg/dl before and 17.2 +/- 4.2 mg/dl after cow's milk ingestion.