Plasma citrulline concentration as a biomarker for bowel loss and adaptation in hospitalized pediatric patients requiring parenteral nutrition.
BACKGROUND
Citrulline is a nonessential amino acid produced solely in the enterocyte. Plasma citrulline concentration has been proposed as a noninvasive biomarker for bowel length, function, and dependency on parenteral nutrition (PN). The purpose of this study was to determine if citrulline concentrations differed between pediatric patients with and without small bowel loss requiring specialized nutrition support.


METHODS
This was a retrospective categorical analysis of citrulline concentrations from previously published studies. Patients were included if they were receiving PN, more than 30 days of age, and if they had at least 2 plasma citrulline concentrations. Patients with renal insufficiency and who received outpatient PN treatment were excluded. Patients were categorized as either having or not having small bowel loss.


RESULTS
Thirty-six patients were included for analysis (18 per category). The median citrulline concentration was significantly lower in the group with bowel loss, 8.4 µmol/L vs 10.5 µmol/L (P < .0005), and undetectable citrulline concentrations occurred more often in the bowel loss group, 40% vs 8% (P < .0005). In 13 patients who received enteral nutrition during the study periods, plasma citrulline concentrations increased only in patients without bowel loss.


CONCLUSIONS
These data confirm previous studies and identify decreased citrulline concentrations in pediatric patients with bowel dysfunction in the absence of bowel loss. These data also represent the first serial citrulline concentrations over a 21-day period. The increase in citrulline concentrations only in fed patients without bowel loss suggests that citrulline concentrations could provide a biomarker for bowel function and adaptation.
University of Tennessee Health Science Center, Department of Clinical Pharmacy, Memphis, Tennessee, USA. jstultz12@gmail.com
Jeremy S
JS
Stultz
Emma M
EM
Tillman
Richard A
RA
Helms
D000222:Adaptation, Physiological; D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000097:blood; D002648:Child; D002675:Child, Preschool; D002956:Citrulline / Q000097:blood*; D020895:Enterocytes / Q000378:metabolism; D005260:Female; D006760:Hospitalization; D006801:Humans; D007223:Infant; D007410:Intestinal Diseases / Q000503:physiopathology / Q000628:therapy; D007421:Intestine, Small / Q000378:metabolism / Q000503:physiopathology; D016014:Linear Models; D008297:Male; D010288:Parenteral Nutrition / Q000379:methods*; D012189:Retrospective Studies; D012778:Short Bowel Syndrome / Q000503:physiopathology / Q000628:therapy*; D055815:Young Adult
D015415:Biomarkers; D002956:Citrulline