A liquid chromatography/mass spectrometry method for the evaluation of intestinal permeability

Objectives: Lactulose to mannitol ratio (L/M) in urine is used as a non invasive assay to measure intestinal permeability. We describe here a rapid, specific and sensitive LC-MS/MS method for the measurement of these compounds in urine of children affected by abdominal recurrent pain (ARP). Design and methods: The study has been performed on 50 children from the Pediatric Unit. The chromatographic separation was accomplished by using an NH2-column, the detection with a Q-Trap 2000 system. Results: Multiple calibration curve exhibited consistent linearity and reproducibility. Linear responses were observed in the concentration range 0400 mu g/mL for both mannitol and lactulose. Limits of detection were 12.5 mg/L for lactulose and 1.25 mg/L for mannitol with a signal-to-noise ratio of 10. Conclusions: The comparison of L/M values of healthy children with those found in children affected by idiopathic ARP demonstrates that in the latter subjects an alteration of intestinal permeability occurs. The method can represent a useful tool to monitor the intestinal functionality in children with ARP conditions and help for an accurate patient discrimination for diet restrictions. (C) 2008 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.