title: Determination of reference values for the soluble transferrin receptor (sTfR) on a cross sectional population sample.
abstract: BACKGROUND
  Aim of the study was to determine reference values for the soluble Transferrin Receptor (sTfR) in a cross sectional population sample.
  
  
  METHODS
  For the determination of reference values, using a standard calibrated fluorescence-immunoassay, the samples (990 females; 1060 males; 13 - 65 years old) were divided into five groups according to age and sex. Soluble transferrin receptor and ferritin were measured by a fluorescence-immunoassay with AIA-21 (TOSOH BIOSCIENCE, Tessenderlo, Belgium). The sTfR/logFer-Index was calculated by dividing the sTfR by the logarithm of ferritin, the logsTfR/Fer-Index by dividing the logarithm of sTfR by ferritin.
  
  
  RESULTS
  Mean sTfR concentration was 1.75 +/- 0.39 mg/l in group I (13-17 years), 1.65 +/- 0.34 mg/l in group II (18-30 years), 1.60 +/- 0.39 mg/l in group III (31-40 years), 1.54 +/- 0.39 mg/l in group IV (41-50 years), and 1.59 +/- 0.34 mg/l in group V (51-65 years), respectively. A gender-specific difference between the groups was observed: sTfR concentrations were lower in group I (p < 0.005) and group II (p = 0.01) for women. The mean sTfR-concentration decreased consecutively in the age group I-IV (13-50 years).
  
  
  CONCLUSIONS
  This is the first cross sectional population based study to determine reference values for sTfR-concentrations. Our results demonstrated age- and gender-specific differences.
authors.affiliation: Universitätsklinikum Ulm, Zentrale Einrichtung für Klinische Chemie, Albert-Einstein-Allee 23, 89070 Ulm, Germany.
authors.forename: Alexa
authors.initials: A
authors.lastname: von Schmiesing
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Schmidt
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kratzer
authors.forename: Richard A
authors.initials: RA
authors.lastname: Mason
authors.forename: Armin
authors.initials: A
authors.lastname: Imhof
authors.forename: Gerald
authors.initials: G
authors.lastname: Steinbach
authors.forename: Atilla S
authors.initials: AS
authors.lastname: Akinli
authors.forename: Mark M
authors.initials: MM
authors.lastname: Haenle
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002097:C-Reactive Protein / Q000378:metabolism; D003430:Cross-Sectional Studies; D005260:Female; D005293:Ferritins / Q000097:blood; D016231:Fluorescence Polarization Immunoassay / Q000379:methods; D006801:Humans; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011990:Receptors, Transferrin / Q000097:blood*; D012016:Reference Values; D012727:Sex Characteristics; D055815:Young Adult
chemical_list: D011990:Receptors, Transferrin; D002097:C-Reactive Protein; D005293:Ferritins