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 NH(2)-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 0-400 microg/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.