J Clin Pathol Qual Control.  2000 Dec;22(2):235-241.

Influence of Iron Depletion on Immature Reticulocyte Fractions and Reticulocyte Maturity Index

• Choi JW
• Pai SH

Abstract

BACKGROUND: To investigate the influence of body iron status on immature reticulocyte fractions and reticulocyte maturity index (RMI), We measured serum iron markers, fluorescent intensity of reticulocytes, and serum transferrin receptor (sTfR) concentrations in 374 female adolescents. METHOED: Reticulocytes and their fractions were automatically analyzed by flow cytometry (R-3000; Sysmex, Kobe, Japan). Serum iron and total iron-binding capacity (TIBC) were assayed with the chemiluminescence method (ACS 180 ; Chiron, USA). Soluble transferrin receptr was measured by immunoenzymometric method (Orion Diagnostica, Finland).
RESULTS
There were no significant differences in the values of reticulocyte fractions and RMI between ferritin alone-depleted group and healthy controls. However, middle- and high- fluorescence reticulocytes (MFR and HFR), and RMI were significantly higher in both serum iron and serum ferritin depleted group than in ferrithin alone-depleted group. MFR and RMI increased gradually as body iron store was depleted and were 3.4- and 3.6-fold higher, respectively than normal controls, when the subjects attained a frank iron deficiency anemia. There were no significant changes in the subjects attained a frank iron deficiency anemia. There were no significant changes in the values of red blood cells and total reticulocyte counts during iron-depleted states. Mean value of sTfR (3.98 mg/L) in the subjects with RMI > 1.5% was significantly higher than that (2.26 mg/L) in the subjects with RMI < 1.5% (p<0.01). The sTfR concentration correlated significantly with RMI (r=0.61, p<0.01) and MFR (r=0.59, p<0.01).
CONCLUSIONS
Body iron depletion induces to elevate immature reticulocyte fractions and RMI. increase of reticulocyte fluorescent intensity during iron-depleted states seems to be influenced by an increased amount of intracellular TfR RNA.

MeSH Terms

Adolescent
Anemia, Iron-Deficiency
Erythrocytes
Ferritins
Flow Cytometry
Fluorescence
Humans
Iron*
Luminescence
Receptors, Transferrin
Reticulocyte Count
Reticulocytes*
RNA
Transferrin
Ferritins
Iron
RNA
Receptors, Transferrin
Transferrin