Plasma Citrulline Concentrations in Neonates and Infants with or without Gastrointestinal Disease and Bowel Resection

Various studies have shown a role for citrulline as a gut mass biomarker in patients with short bowel syndrome. Our hypothesis is that plasma citrulline is both a gastrointestinal (GI) function and a gut mass marker. Our objective was to validate previous observations, by prospectively analyzing plasma citrulline concentrations in patients with GI disease with or without bowel resection, compared to patients without GI disease. Plasma from blood samples of parenteral nutrition fed neonates and infants was obtained. Samples were analyzed by ion-exchange chromatography. Data collected included age, diagnoses and surgical documentation of bowel resection. Patients were classified into 3 main groups: those without GI disease nor resection (Group 1), those with GI disease but no resection (Group 2), and those with GI disease and resection (Group 3). Group medians were compared using KruskalWallis ANOVA. Seventeen samples were evaluated. Patients in Group 3 were older compared to patients in Groups 1 and 2; median age (in days) 156 vs. 12 vs. 57 respectively. Median (range) plasma citrulline concentrations were 20.9 (14.9 29.0) μmol/L, 8.7 (0.5 20.0) μmol/L and 9.6 (5.9 13.2) μmol/L for Groups 1, 2 and 3 respectively. There were significant differences among medians and sample distributions between Groups 1 and 2 and between 1 and 3 (p < 0.05). No differences were observed between Groups 2 and 3. Patients without GI disease and no resection had significantly higher plasma citrulline concentrations than patients with GI disease with or without resection at the time of assessment.