title: An association of lower serum citrulline levels within 30 days of acute rejection in patients following small intestine transplantation.
abstract: BACKGROUND
  In a prospective protocol we studied whether serum citrulline level within 30 days of an acute rejection was predictive of the episode.
  
  
  METHODS
  An acute rejection episode was defined as the date of occurrence of any biopsy-proven rejection in which treatment was initiated until two successive biopsies showed no further rejection. We compared the mean citrulline level based on values determined within 30 days of the start of an acute rejection episode with the mean citrulline level measured on the same patient during a rejection-free period. Serum citrulline measurements were available immediately prior to the occurrence of rejection for 22 patients who experienced 37 episodes.
  
  
  RESULTS
  For the 12 episodes of mild rejection, the mean serum citrulline level +/- SE (standard error) was 15.0 + 2.3 micromol/L prior to rejection and 18.8 +/- 2.4 micromol/L during the rejection-free periods. A paired t test of the mean differences was not significant (P = 17). For the 25 episodes of moderate or severe rejection, the mean serum citrulline level was 12.4 +/- 1.1 micromol/L before rejection and 18.8 +/- 2.0 micromol/L during the rejection-free periods. A paired t test of the mean difference was statistically significant (P = .002).
  
  
  CONCLUSIONS
  Although further study of citrulline as a marker for the early detection of acute rejection episodes is needed, our hope is that its use will help to prevent some of these early episodes from evolving into full-blown moderate or severe grades of rejection.
authors.affiliation: Department of Surgery, Division of Liver and GI Transplant, University of Miami Miller School of Medicine, Miami, FL 33136, USA. andredavid@medscape.com
authors.forename: A I
authors.initials: AI
authors.lastname: David
authors.forename: J J
authors.initials: JJ
authors.lastname: Gaynor
authors.forename: P P
authors.initials: PP
authors.lastname: Zis
authors.forename: L
authors.initials: L
authors.lastname: Conanan
authors.forename: L
authors.initials: L
authors.lastname: Goldsmith
authors.forename: V
authors.initials: V
authors.lastname: Esquenazi
authors.forename: G
authors.initials: G
authors.lastname: Selvaggi
authors.forename: D
authors.initials: D
authors.lastname: Weppler
authors.forename: S
authors.initials: S
authors.lastname: Nishida
authors.forename: J
authors.initials: J
authors.lastname: Moon
authors.forename: J R
authors.initials: JR
authors.lastname: Madariaga
authors.forename: P
authors.initials: P
authors.lastname: Ruiz
authors.forename: T
authors.initials: T
authors.lastname: Kato
authors.forename: D M
authors.initials: DM
authors.lastname: Levi
authors.forename: G
authors.initials: G
authors.lastname: Kleiner
authors.forename: P
authors.initials: P
authors.lastname: Tryphonopoulos
authors.forename: A G
authors.initials: AG
authors.lastname: Tzakis
mesh_terms: D000208:Acute Disease; D000328:Adult; D015415:Biomarkers / Q000097:blood; D002648:Child; D002956:Citrulline / Q000097:blood*; D006084:Graft Rejection / Q000097:blood* / Q000145:classification / Q000175:diagnosis; D006801:Humans; D007421:Intestine, Small / Q000637:transplantation*; D011184:Postoperative Period; D011446:Prospective Studies; D014184:Transplantation, Homologous / Q000473:pathology
chemical_list: D015415:Biomarkers; D002956:Citrulline