Soluble
transferrin receptor (sTfR) is a new diagnostic tool for determining
iron status and erythropoietic activity. The increased concentrations of sTfR in patients with
iron deficiency reflect the
hyperplasia of erythroid precursors. The objective of this study was to evaluate sTfR and sTfR/log
ferritin index (sTfR-F) values in healthy children (n = 64), full-term neonates (n = 18), children with
iron deficiency (n = 16),
hemolytic anemia (n = 7),
beta-thalassemia traits (n = 18),
respiratory infections (n = 41) and
malignancies (n = 13), and to compare these parameters for the different subgroups with those of healthy children. The sTfR levels were increased in children with
iron deficiency in the same way as in adults (p < 0.0001) and in cases of increased erythropoietic activity, such as during the neonatal period (p < 0.0001), and of hemolytic
anemias (p = 0.006). The index was significantly increased in
iron deficiency (p < 0.0001) and decreased in neonates (p = 0.011). Children carriers of
beta-thalassemia were found to have increased sTfR values (p = 0.015), but not sTfR/log
ferritin index (p = 0.491), a finding suggesting that use of both parameters is necessary for distinguishing between those with and those without
iron deficiency. In children with upper respiratory
infection, the sTfR levels were close to normal, while the index was found to be low. In order to evaluate the
iron status in
infections, we further subdivided the children into two groups according to the value of
ferritin, with the cut-off point at 35 microg/L. Children with
ferritin level above 35 microg/L experienced normal sTfR levels but very low index, a finding which could enable the use of these two parameters for distinguishing patients with
infection without concomitant
iron deficiency. In the group of
malignancies under
chemotherapy both indices were low (p = 0.005, p < 0.0001) mainly due to myelosuppression.
CONCLUSION: