title: Normal values for pancreatic stone protein in different age groups.
abstract: BACKGROUND
  Pancreatic stone protein (PSP) has been identified as a promising sepsis marker in adults, children and neonates. However, data on population-based reference values are lacking. This study aimed to establish age-specific reference values for PSP.
  
  
  METHODS
  PSP was determined using a specific ELISA. PSP serum concentrations were determined in 372 healthy subjects including 217 neonates, 94 infants and children up to 16 years, and 61 adults. The adjacent categories method was used to determine which age categories had significantly different PSP concentrations.
  
  
  RESULTS
  PSP circulating levels were not gender-dependent and ranged from 1.0 to 99.4 ng/ml with a median of 9.2 ng/ml. PSP increased significantly between the age categories, from a median of 2.6 ng/ml in very preterm newborns, to 6.3 ng/ml in term newborns, to 16.1 ng/ml in older children (p < 0.001). PSP levels were higher on postnatal day three compared to levels measured immediately post delivery (p < 0.001). Paired umbilical artery and umbilical vein samples were strongly correlated (p < 0.001). Simultaneously obtained capillary heel-prick versus venous samples showed a good level of agreement for PSP (Rho 0.89, bias 19 %).
  
  
  CONCLUSIONS
  This study provides age-specific normal values that may be used to define cut-offs for future trials on PSP. We demonstrate an age-dependent increase of PSP from birth to childhood.
authors.affiliation: Mater Research Institute, Paediatric Critical Care Research Group, University of Queensland, Brisbane, Australia. l.schlapbach@uq.edu.au.|Paediatric Intensive Care Unit, Lady Cilento Children's Hospital, Children's Health Queensland, South Brisbane, QLD, 4101, Australia. l.schlapbach@uq.edu.au.|Department of Pediatrics, University of Bern, Bern, Switzerland. l.schlapbach@uq.edu.au.
authors.forename: Luregn J
authors.initials: LJ
authors.lastname: Schlapbach
authors.affiliation: Service of Neonatology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland. eric.giannoni@chuv.ch.|Infectious Diseases Service, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland. eric.giannoni@chuv.ch.
authors.forename: Eric
authors.initials: E
authors.lastname: Giannoni
authors.affiliation: Department of Neonatology, University Children's Hospital Basel, Basel, Switzerland. sven.wellmann@ukbb.ch.
authors.forename: Sven
authors.initials: S
authors.lastname: Wellmann
authors.affiliation: Neonatal and Pediatric Intensive Care Unit, Children's Hospital Lucerne, Lucerne, Switzerland. martin.stocker@luks.ch.
authors.forename: Martin
authors.initials: M
authors.lastname: Stocker
authors.affiliation: Department of Pediatrics, University of Bern, Bern, Switzerland. roland.ammann@insel.ch.
authors.forename: Roland A
authors.initials: RA
authors.lastname: Ammann
authors.affiliation: Department of Surgery, Swiss HPB Center, University Hospital Zurich, Zurich, Switzerland. rolf.graf@usz.ch.
authors.forename: Rolf
authors.initials: R
authors.lastname: Graf
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D015415:Biomarkers / Q000097:blood; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D051847:Lithostathine / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D055815:Young Adult
chemical_list: D015415:Biomarkers; D051847:Lithostathine