title: Beta-trace protein--a marker of kidney function in children: "Original research communication-clinical investigation".
abstract: OBJECTIVE
  To determine the pediatric reference interval for serum beta-trace protein (beta-TP) and to compare beta-TP with established LMW markers of GFR, i.e., cystatin C (CysC) and beta(2)-microglobulin (beta(2)-M).
  
  
  METHODS
  All three LMW markers were measured immunonephelometrically. In 106 children above the age of 2 years without evidence of kidney disease, non-parametric reference intervals were calculated. The relative rise of the GFR marker concentrations above the upper reference was studied in 107 samples from 96 patients covering the entire GFR range.
  
  
  RESULTS
  Above 2 years, the reference range of beta-TP was constant at 0.43-1.04 mg/L. With decreasing Schwartz-GFR, there was a comparable rise in beta-TP and beta(2)-M, while CysC rose less in the group with GFR below 30 mL/min/1.73 m(2) (278+/-49% [CysC] versus 336+/-65% [beta-TP] and 342+/-76% [beta(2)-M]; p=0.043 and 0.027, respectively).
  
  
  CONCLUSIONS
  These data confirm the potential of ss-TP as an endogenous GFR marker in children.
authors.affiliation: Children's Hospital, Bonn University Medical Center, Bonn, Germany. Bokenkamp@VUmc.nl
authors.forename: Arend
authors.initials: A
authors.lastname: Bökenkamp
authors.forename: Ingo
authors.initials: I
authors.lastname: Franke
authors.forename: Michael
authors.initials: M
authors.lastname: Schlieber
authors.forename: Gesche
authors.initials: G
authors.lastname: Düker
authors.forename: Joachim
authors.initials: J
authors.lastname: Schmitt
authors.forename: Stefan
authors.initials: S
authors.lastname: Buderus
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lentze
authors.forename: Birgit
authors.initials: B
authors.lastname: Stoffel-Wagner
mesh_terms: D000293:Adolescent; D015415:Biomarkers / Q000097:blood*; D002648:Child; D055316:Cystatin C; D015891:Cystatins / Q000097:blood; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D019746:Intramolecular Oxidoreductases / Q000097:blood*; D007677:Kidney Function Tests; D054834:Lipocalins; D008297:Male; D001613:beta 2-Microglobulin / Q000097:blood
chemical_list: D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins; D054834:Lipocalins; D001613:beta 2-Microglobulin; D019746:Intramolecular Oxidoreductases; C022466:prostaglandin R2 D-isomerase