title: Reduced early dried blood spot citrulline levels in preterm infants with meconium obstruction of prematurity.
abstract: BACKGROUND
  Citrulline is a non-protein amino acid synthesized in the enterocytes of the small bowel. Recent studies have reported that plasma citrulline levels correlate with functional enterocyte mass.
  
  
  OBJECTIVE
  This study aimed to determine the normal dried blood spot (DBS) citrulline levels and to determine the existence of a correlation between citrulline levels and meconium obstruction of prematurity (MOP).
  
  
  METHODS
  A retrospective cohort study was performed involving 285 infants born at less than 32weeks gestation who were admitted to the neonatal intensive care unit between Oct 2009 and Aug 2014.
  
  
  METHODS
  We analyzed the DBS citrulline levels, which are routinely measured via newborn screening at 7days following birth, using liquid chromatography-MS/MS. We investigated the relationship between DBS citrulline levels and clinical parameters such as gestational age (GA), body measurements at birth, gender, or the presence or absence of either necrotizing enterocolitis or MOP.
  
  
  RESULTS
  A total of 229 infants with a median GA of 29.6weeks and a median birth weight of 1160g were included. DBS citrulline levels were not associated with GA, body measurements at birth or gender. DBS citrulline levels were significantly decreased when patients presented with MOP (p=0.037).
  
  
  CONCLUSIONS
  Early DBS citrulline levels were not associated with either GA or body measurements at birth but were reduced among preterm infants with MOP compared with the control infants. These results may be indicative of abnormal fetal intestinal development and reduced functional enterocyte mass among preterm infants with MOP.
authors.affiliation: Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Hae Kyung
authors.initials: HK
authors.lastname: Woo
authors.affiliation: Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea. Electronic address: kimek@snu.ac.kr.
authors.forename: Ee-Kyung
authors.initials: EK
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Young Hwa
authors.initials: YH
authors.lastname: Jung
authors.affiliation: Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Seung Han
authors.initials: SH
authors.lastname: Shin
authors.affiliation: Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Han-Suk
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Pediatrics, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Jung-Hwan
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Pediatric Surgery, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Hyun-Young
authors.initials: HY
authors.lastname: Kim
mesh_terms: D002956:Citrulline / Q000097:blood*; D020345:Enterocolitis, Necrotizing / Q000097:blood / Q000175:diagnosis*; D020895:Enterocytes; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000097:blood; D007235:Infant, Premature, Diseases / Q000097:blood / Q000175:diagnosis*; D007415:Intestinal Obstruction / Q000097:blood / Q000175:diagnosis*; D008297:Male; D008470:Meconium; D015997:Neonatal Screening; D012189:Retrospective Studies
chemical_list: D002956:Citrulline
keywords: Bowel obstruction; Citrulline; Dried blood spots; Meconium; Premature infant