title: Robust reference intervals for liver function test (LFT) analytes in newborns and infants.
abstract: BACKGROUND
  Reference intervals (RIs) are ranges of upper and lower limits of a given analyte which are used for a laboratory test to determine whether a disease is present or absent or to know if the patient is at risk for future disease states. In Ethiopia, a country with highly diversified population groups and geographical sites, there are no established RIs to metabolic analytes including the liver function test (LFT) analytes for the pediatric population though it has been known that liver function assessment in this population is vital as a result of varied vulnerability to both endogenous and xenobiotic substances.
  
  
  METHODS
  A cross sectional study was conducted in Tikur Anbessa Specialized Hospital (TASH) and Teklehaymanot Health Center (THC) from November 2010 to April 2011. 117 cord blood (from newborns) and venous blood samples (from infants) were collected and analyzed using HumaStar 300. All pre-analytical, analytical and post-analytical aspects were thoroughly controlled. A robust, CLSI/ IFCC recommended, method was used for the determination of upper and lower end points covering 95% of the reference values of each analyte with respective 90% CIs using MedCalc® software.
  
  
  RESULTS
  Combined RIs for newborns and infants were established for albumin, AST, ALP, direct bilirubin and total bilirubin to be 3.88-5.82 g/dl, 16.1-55.4U/l, 130-831U/l, <0.41 mg/dl and <1.37 mg/dl respectively. But, separated RIs were indicated for ALT and GGT as 1.2-23.1U/l and 6.94-24.8U/l ALT; and 30.6-160.7U/L and 10-28.2U/l GGT for newborns and infants respectively. Some maternal and infantile factors were identified to affect the values of analytes.
  
  
  CONCLUSIONS
  Almost all analytes were different from previously reported values for other target population of similar age group, kit insert values and adult values. So, interpretation of values of these analytes in newborns and infants of Ethiopian population sounds better to be performed by using such RIs taking the effect of some maternal and infantile factors in to account.
authors.affiliation: Department of Medical Laboratory Science, Arbaminch University, Arbaminch, Ethiopia. mulstud@gmail.com
authors.forename: Mulugeta
authors.initials: M
authors.lastname: Melkie
authors.forename: Mahilet
authors.initials: M
authors.lastname: Yigeremu
authors.forename: Paulos
authors.initials: P
authors.lastname: Nigussie
authors.forename: Shawel
authors.initials: S
authors.lastname: Asrat
authors.forename: Tatek
authors.initials: T
authors.lastname: Gebreegziabher
authors.forename: Tilahun
authors.initials: T
authors.lastname: Teka
authors.forename: Samuel
authors.initials: S
authors.lastname: Kinde
mesh_terms: D000328:Adult; D000410:Alanine Transaminase / Q000097:blood; D000469:Alkaline Phosphatase / Q000097:blood; D001219:Aspartate Aminotransferases / Q000097:blood; D001663:Bilirubin / Q000097:blood; D044383:Black People; D003151:Community Health Centers; D003430:Cross-Sectional Studies; D005002:Ethiopia; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008111:Liver Function Tests / Q000592:standards*; D008297:Male; D012016:Reference Values; D012709:Serum Albumin / Q000032:analysis; D005723:gamma-Glutamyltransferase / Q000097:blood
chemical_list: D012709:Serum Albumin; D005723:gamma-Glutamyltransferase; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D000469:Alkaline Phosphatase; D001663:Bilirubin