title: Associations between serum transferrin receptor concentrations and erythropoietic activities according to body iron status.
abstract: This study investigated the associations between serum transferrin receptor (sTfR) concentrations and erythropoietic activities during 3 stages of iron deficiency in humans. Serum iron markers, fluorescent intensity of reticulocytes, and sTfR concentrations were measured in 227 prepubescent children, age 9 to 12 yr. Reticulocyte subpopulations were analyzed by flow cytometry and sTfR concentrations were measured by enzyme immunoassay. Mean values of middle-fluorescence reticulocytes (MFR), reticulocyte maturity index (RMI), and sTfR concentrations were significantly higher in iron-deficiency anemia subjects than in healthy controls. Reticulocyte subpopulations increased gradually, as body iron status diminished; the mean values of MFR and RMI in subjects with serum ferritin concentrations < 4.0 microg/L were 3-fold higher than those in healthy controls (p < 0.01). Correlation coefficients of MFR and RMI vs log ferritin values (r = 0.43 and r = 0.42) were higher than those of MFR and RMI vs sTfR concentrations (r = 0.24 and r = 0.27) in iron-deficiency anemia subjects. In summary, iron deficiency leads to increased production of immature reticulocytes. Erythropoietic activity is more closely associated with log ferritin values than with sTfR concentrations in iron-deficiency anemia.
authors.affiliation: Department of Laboratory Medicine, College of Medicine, Inha University, Inchon, South Korea. jwchoi@inha.ac.kr
authors.forename: Jong Weon
authors.initials: JW
authors.lastname: Choi
authors.forename: Soo Hwan
authors.initials: SH
authors.lastname: Pai
mesh_terms: D018798:Anemia, Iron-Deficiency / Q000097:blood*; D015415:Biomarkers; D002648:Child; D004909:Erythrocyte Indices; D004920:Erythropoiesis / Q000502:physiology*; D005260:Female; D005293:Ferritins / Q000378:metabolism; D005434:Flow Cytometry; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008297:Male; D011990:Receptors, Transferrin / Q000097:blood*; D012016:Reference Values; D017701:Reticulocyte Count; D012156:Reticulocytes / Q000502:physiology*
chemical_list: D015415:Biomarkers; D011990:Receptors, Transferrin; D005293:Ferritins; D007501:Iron