title: [Plasma citrulline concentration as a biomarker of intestinal function in short bowel syndrome and in intestinal transplant].
abstract: BACKGROUND
  Citrulline is a non-essential amino acid produced solely in the enterocyte. The aim of this study was to analyse the role of serum citrulline as a biomarker of enterocyte load in children with intestinal failure due to short bowel syndrome (SBS) and its relationship to enteral adaptation.
  
  
  METHODS
  Plasma citrulline concentration was determined by chromatography (normal value>15 μmol/L) in 57 patients (age 0.5-18 years) admitted to our Intestinal Rehabilitation Unit with intestinal failure. Those who were dehydrated, with renal insufficiency, or other conditions able to modify the results were excluded. Patients were divided into 4 groups: group i: SBS totally dependent on parenteral nutrition (PN); group ii: SBS under mixed enteral-parenteral nutrition; group iii: IF weaned from PN after a rehabilitation period; group iv: small bowel transplanted patients weaned from PN and taking a normal diet.
  
  
  RESULTS
  The mean ± SD plasma citrulline values were: group i (n=15): 7.1 ± 4.1; group ii (n=11): 15.8 ± 8.9; group iii (n=13): 20.6 ± 7.5; group iv (n=25): 28.8 ± 10.1. Values were significantly lower in group i in comparison with groups ii-iii-iv (P<.001), and in group ii in comparison with groups iii-iv (P<.001). A low citrulline was associated with remnant small bowel length (P<.001, r=0.85). In group iv citrulline levels decreased >50% in 3 patients who developed moderate-severe rejection, and in one patient who developed viral enteritis.
  
  
  CONCLUSIONS
  1. Plasma citrulline could be a sensitive and specific biomarker of the residual functional enterocyte load. 2. It is related to enteral feeding tolerance. 3. Its prognostic value in the process of intestinal adaptation and as a rejection marker in small bowel transplanted patients needs to be confirmed.
authors.affiliation: Servicio de Gastroenterología Infantil, Hospital Infantil La Paz, Madrid, España. Electronic address: rvecinolopez@gmail.com.
authors.forename: R
authors.initials: R
authors.lastname: Vecino López
authors.forename: A M
authors.initials: AM
authors.lastname: Andrés Moreno
authors.forename: E
authors.initials: E
authors.lastname: Ramos Boluda
authors.forename: E
authors.initials: E
authors.lastname: Martinez-Ojinaga Nodal
authors.forename: A
authors.initials: A
authors.lastname: Hernanz Macías
authors.forename: G
authors.initials: G
authors.lastname: Prieto Bozano
authors.forename: M
authors.initials: M
authors.lastname: Lopez Santamaria
authors.forename: J A
authors.initials: JA
authors.lastname: Tovar Larrucea
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000097:blood; D002648:Child; D002675:Child, Preschool; D002956:Citrulline / Q000097:blood*; D020895:Enterocytes / Q000502:physiology; D005260:Female; D006801:Humans; D007223:Infant; D007422:Intestines / Q000503:physiopathology* / Q000637:transplantation*; D008297:Male; D011183:Postoperative Complications / Q000097:blood* / Q000503:physiopathology*; D012778:Short Bowel Syndrome / Q000097:blood* / Q000503:physiopathology*
chemical_list: D015415:Biomarkers; D002956:Citrulline
keywords: Biomarcador; Biomarker; Citrulina; Citrulline; Fracaso intestinal; Intestinal failure; Intestinal transplantation; Nutrición parenteral; Parenteral nutrition; Short bowel syndrome; Síndrome de intestino corto; Trasplante intestinal