Limitations of using citrulline levels as a marker of gastrointestinal function in patients with chronic intestinal failure.

BACKGROUND AND AIMS: Citrulline (CIT), produced almost exclusively by enterocytes, is a potentially sensitive biomarker of small intestine absorptive function in patients with chronic intestinal failure (CIF). The aim of this study was to evaluate the utility and limitations of plasma citrulline (CIT) level measurements in assessing gastrointestinal function in patients with chronic intestinal failure (CIF), including a comparison between patients with and without cancer.

METHODS

The study was conducted among 56 CIF patients. The study of the profile of plasma CIT was performed by tandem mass spectrometry (LC-MS/MS) technique. The retrospective data analysis has included the average weekly volume of parenteral nutrition mixture (ml), average weekly volume of intravenous fluid and electrolyte infusions, duration of HPN, energy (kcal) and amino acids (g), and analysis of medical history. Body composition testing was performed with a Tanita MC-780 S MA body composition analyzer.

RESULTS

Analyses showed that individuals without active cancer (M = 20.94; SD = 10.55) had significantly higher plasma CIT levels compared to the group with active cancer (M = 14.77; SD = 7.26). There were no statistically significant differences in CIT levels (p = 0.466) among the three subgroups of SBS patients. No correlation was found between plasma citrulline levels and the duration of parenteral nutrition, nitrogen dose in the parenteral solution, energy requirements, intravenous fluid and electrolyte needs, or nutritional status.

CONCLUSIONS

Plasma citrulline level is not a useful biomarker of intestinal adaptation in the group of subjects with CIF. Long-term multicenter studies are necessary to assess the usefulness of CIT in evaluating gastrointestinal function in CIF.