Background: Serum transferrin receptor (sTfR) is a reliable tool for assessing functional iron status and erythropoietic activity in adults, but little is known about its role in children.
Objective: To evaluate sTfR concentrations in healthy children and age and sex-related variations. A further aim was to determine the relationship of these concentrations with other iron parameters and with erythropoietin.
Patients and methods: Blood samples from 155 healthy children aged 1-10 years old were obtained to determine sTfR, iron status indices and erythropoietin. The sTfR/ferritin ratio and the sTfR-ferritin index (sTfR/log ferritin) were calculated. Iron deficiency and increased erythropoiesis were eliminated.
Results: Values of sTfR, the sTfR/ferritin ratio and the sTfR-F index were 1.94 0.41mg/L (95 % CI: 1.14-2.74 mg/L), 83 40.3 (95 % CI: 4-162) and 1.4 0.36 (95 % CI: 0.69-2.1) respectively. No significant sex-related differences were found. Children aged 1-2 years old showed the highest sTfR levels. sTfR was directly related to erythrocyte count (r: 0.17; p < 0,03), hemoglobin level (r: 0.16; p < 0.05) and total iron binding capacity (r: 0.258; p < 0,001). In the multiple linear regression analysis, the best predictors of sTfR concentrations were log erythropoietin (p < 0.016) and total iron binding capacity (p < 0.0001).
Conclusions: sTfR concentrations are elevated in children due to increased iron requirements for growth. In healthy children sTfR concentrations are related to erythropoietic activity and intracellular iron requirements. The current data are useful as a standard reference for healthy children.