title: Pediatric reference intervals for soluble transferrin receptor and transferrin receptor-ferritin index.
abstract: BACKGROUND
  Recent studies showing an improved diagnosis of iron deficiency (ID) with soluble transferrin receptor (sTfR) and sTfR-ferritin index did not take into account the age-dependency of sTfR and ferritin. Moreover, there is a paucity of data on pediatric reference intervals for sTfR and sTfR-ferritin index.
  
  
  METHODS
  A study cohort of 436 apparently healthy children was analyzed to establish reference intervals for ferritin, transferrin, sTfR and sTfR-ferritin index. To account for age-dependency, standard deviation scores (Z-scores) for these markers were calculated. The association between these parameters and C-reactive protein (CRP) was analyzed.
  
  
  RESULTS
  The Z-scores of ferritin, transferrin and sTfR had a significant association with CRP, whereas the Z-score of sTfR-ferritin did not correlate with CRP. The reference intervals of these parameters were reported.
  
  
  CONCLUSIONS
  Among the different markers of ID, the Z-scores of sTfR, transferrin and ferritin, but not sTfR-ferritin index, associate with the inflammatory status.
authors.affiliation: Department of Pediatrics, Children's Hospital, London Health Science Centre, Schulich School of Medicine & Dentistry, University of Western Ontario, 800 Commissioners Road East, London, Ontario, N6A 7W9, Canada.
authors.forename: Cara Lianne
authors.initials: CL
authors.lastname: Ooi
authors.forename: Nathalie
authors.initials: N
authors.lastname: Lepage
authors.forename: Ed
authors.initials: E
authors.lastname: Nieuwenhuys
authors.forename: Ajay Parkash
authors.initials: AP
authors.lastname: Sharma
authors.forename: Guido
authors.initials: G
authors.lastname: Filler
mesh_terms: D000293:Adolescent; D000465:Algorithms; D018798:Anemia, Iron-Deficiency / Q000097:blood* / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005293:Ferritins / Q000097:blood*; D006776:Hospitals, Pediatric; D006801:Humans; D007223:Infant; D007501:Iron / Q000097:blood*; D000090463:Iron Deficiencies; D008297:Male; D011237:Predictive Value of Tests; D011990:Receptors, Transferrin / Q000097:blood*; D012016:Reference Values; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
chemical_list: D015415:Biomarkers; D011990:Receptors, Transferrin; D002097:C-Reactive Protein; D005293:Ferritins; D007501:Iron