title: Elevated Alkaline Phosphatase in Infants With Parenteral Nutrition-Associated Liver Disease Reflects Bone Rather Than Liver Disease.
abstract: BACKGROUND
  Elevated serum alkaline phosphatase (ALP) in infants with intestinal failure (IF) can be due to parenteral nutrition-associated liver disease (PNALD) or metabolic bone disease (MBD). The purpose of the study was to determine the utility of serum ALP in the diagnostic criteria for PNALD by measuring tissue-specific levels in infants with IF and PNALD.
  
  
  METHODS
  A retrospective review of patient data for 15 infants diagnosed with PNALD between December 2012 and August 2013 was performed. PNALD was defined as the presence of 2 consecutive direct bilirubin (DB) levels >2 mg/dL. Fractionated serum alkaline phosphatase was measured in each patient, while the DB was >2 mg/dL. Parathyroid hormone (PTH), vitamin D3, calcium, and phosphate levels were recorded where available.
  
  
  RESULTS
  In 15 infants with PNALD, elevation in total ALP was due to marked elevations in bone-specific ALP. The median liver-specific ALP remained within the normal range. PTH, vitamin D3, calcium, and phosphate levels were within normal limits.
  
  
  CONCLUSIONS
  While elevated ALP can reflect biliary stasis, the ALP elevation observed in infants with IF and PNALD is predominantly of bone rather than hepatic origin. An elevated unfractionated ALP in infants with PNALD should therefore raise suspicion of underlying bone disease, rather than being attributed to liver disease alone.
authors.affiliation: The Vascular Biology Program and Department of Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Prathima
authors.initials: P
authors.lastname: Nandivada
authors.affiliation: The Vascular Biology Program and Department of Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Alexis K
authors.initials: AK
authors.lastname: Potemkin
authors.affiliation: The Vascular Biology Program and Department of Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Carlson
authors.affiliation: The Vascular Biology Program and Department of Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Melissa I
authors.initials: MI
authors.lastname: Chang
authors.affiliation: The Vascular Biology Program and Department of Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Eileen
authors.initials: E
authors.lastname: Cowan
authors.affiliation: The Vascular Biology Program and Department of Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Alison A
authors.initials: AA
authors.lastname: O'Loughlin
authors.affiliation: Department of Pharmacy, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Gura
authors.affiliation: The Vascular Biology Program and Department of Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts Mark.puder@childrens.harvard.edu.
authors.forename: Mark
authors.initials: M
authors.lastname: Puder
mesh_terms: D000469:Alkaline Phosphatase / Q000097:blood*; D001663:Bilirubin / Q000097:blood*; D001851:Bone Diseases, Metabolic / Q000097:blood* / Q000175:diagnosis; D001842:Bone and Bones / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007223:Infant; D007410:Intestinal Diseases / Q000628:therapy; D008099:Liver / Q000378:metabolism* / Q000473:pathology; D008107:Liver Diseases / Q000097:blood* / Q000175:diagnosis / Q000209:etiology; D008111:Liver Function Tests; D010288:Parenteral Nutrition / Q000009:adverse effects*; D012189:Retrospective Studies
chemical_list: D000469:Alkaline Phosphatase; D001663:Bilirubin
keywords: gastroenterology; life cycle; neonates; nutrition; parenteral nutrition; research and diseases