title: Utilization of dried blood spot citrulline level as a noninvasive method for monitoring graft function following intestinal transplantation.
abstract: BACKGROUND
  Citrulline concentrations have been proposed as a marker for intestinal allograft rejection. We instituted dried blood spot (DBS) specimen monitoring of citrulline to simplify sample collection posttransplant. This study demonstrates the correlation between plasma and dried blood spot specimen citrulline concentrations after intestinal transplantation.
  
  
  METHODS
  Plasma and DBS samples were analyzed by hydrophilic interaction chromatography tandem mass spectrometry. Comparison of the strength of linear correlation was made according to the type of surgery, sonication time, DBS citrulline levels, and the time interval between the blood sample collection and the assay date.
  
  
  RESULTS
  A very strong linear correlation exists between the plasma and DBS citrulline concentrations (r=0.87; P<0.001). The correlation between plasma and DBS citrulline concentrations was maintained when evaluating only the intestinal transplant recipients. There was no significant difference in the strength of linear correlation according to sonication time, cirtrulline concentrations, or length of time to assay date.
  
  
  CONCLUSIONS
  DBS citrulline monitoring will ease sample collection following intestinal transplantation and improve the ability to detect intestinal dysfunction and rejection by a noninvasive means.
authors.affiliation: Department of Surgery, Division of Transplantation, University of Miami School of Medicine, Miami, FL 33136, USA.
authors.forename: Hee Chul
authors.initials: HC
authors.lastname: Yu
authors.forename: Sony
authors.initials: S
authors.lastname: Tuteja
authors.forename: Jang Il
authors.initials: JI
authors.lastname: Moon
authors.forename: Gary I
authors.initials: GI
authors.lastname: Kleiner
authors.forename: Lobella
authors.initials: L
authors.lastname: Conanan
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Gaynor
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Kato
authors.forename: David M
authors.initials: DM
authors.lastname: Levi
authors.forename: Seigo
authors.initials: S
authors.lastname: Nishida
authors.forename: Gennaro
authors.initials: G
authors.lastname: Selvaggi
authors.forename: Carlos
authors.initials: C
authors.lastname: Gandia
authors.forename: Debbie
authors.initials: D
authors.lastname: Weppler
authors.forename: Violet
authors.initials: V
authors.lastname: Esquenazi
authors.forename: Phillip
authors.initials: P
authors.lastname: Ruiz
authors.forename: Joshua
authors.initials: J
authors.lastname: Miller
authors.forename: Andreas G
authors.initials: AG
authors.lastname: Tzakis
mesh_terms: D000328:Adult; D000368:Aged; D001800:Blood Specimen Collection / Q000379:methods; D002648:Child; D002675:Child, Preschool; D002956:Citrulline / Q000097:blood*; D005260:Female; D006498:Hepatectomy; D006801:Humans; D007223:Infant; D007422:Intestines / Q000637:transplantation*; D016031:Liver Transplantation / Q000502:physiology; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods; D014184:Transplantation, Homologous / Q000502:physiology*
chemical_list: D002956:Citrulline