Reference values of serum transferrin receptor (sTfR) and sTfR/log ferritin index in healthy children

Abstract

ABSTARCT The aims of this study were to determine appropriate reference ranges for serum transferrin receptor (sTfR) and sTfR/log ferritin (sTfR-F index) in healthy children and their relationship with iron parameters, erythropoiesis, and other conditions presented by the subject. A total of 902 children with normal iron status, aged 1-11 years, were included in a cross-sectional study. A physical examination was conducted and z-score of body mass index (zBMI) obtained. Complete blood count, iron biomarkers, erythropoietin, C-reactive protein, sTfR, and sTfR/log ferritin were determined. Linear multiple regression was applied to identify the factors that determined sTfR and sTfR-F index variability. Mean values for sTfR and sTfR-F index were 1.22 ± 0.28 mg/L (95% confidence interval [CI]: 1.2-1.23) and 0.87 ± 0.25 (95% CI: 0.85-0.88). The reference intervals (2.5th to 97.5th percentiles [P2.5-P97.5]) were 0.78-1.9 mg/L and 0.49-1.46, respectively. sTfR and sTfR-F values decreased with age (P <.03 and P <.0001, respectively). No changes were observed with sex. Changes in sTfR and sTfR-F index were consistent with ferritin and erythropoietin variations. Iron biomarkers, erythropoietin, and zBMI predicted 19% and 18.1% of the sTfR and sTfR-F index variability. The results provide reference ranges for sTfR and sTfR-F index in healthy children for clinical use in the assessment of body iron status. Both biomarkers are predicted by iron parameters, erythropoietin, and zBMI.

The prevalence and factors associated with stunting among infants aged 6 months in a peri-urban South African community

“…Infants with higher sTfR (mg/l) concentrations were 1•12 times more likely (P = 0•021) to be stunted than those with lower sTfR (mg/l) concentrations in logistic regression analysis (model 3, Table 5). The 30•1 % prevalence of iron deficiency based on sTfR observed in the present study may be a more accurate reflection of true iron deficiency, compared with the 16•0 % prevalence based on PF (25,40) . The coexistence of stunting and iron deficiency in the study infants may reflect underlying poor maternal nutrition (41) .…”

Perspective: What Makes It So Difficult to Mitigate Worldwide Anemia Prevalence?

“…The ratio between sTfR and log serum ferritin concentrations (sTfR:log ferritin) combines these 2 variables to differentiate between iron deficiency and inflammation. A ratio of sTfR to log ferritin <1 indicates ACD, whereas values >2 indicate IDA or a mixture of iron deficiency and chronic diseases (89,91). As can be seen in textbooks [e.g., (1)], normative values for all of these variables show agerelated changes, which can be taken from the textbooks (e.g., 1).…”

Prevalence of Anemia, Iron Deficiency, and Iron Deficiency Anemia and Diagnostic Performance of Hematologic and Biochemical Markers of Sideropenia in 1- To 5-Year-Old Children in Thrace Greece

“… 12 However, the above ratio has not been adequately studied in infants and children, and limited studies have been performed to determine its reference range and cutoff values for ID. 10 , 12 – 15 …”

“…5 Therefore, the ratio of sTfR to the common logarithm of serum ferritin concentration, also known as the sTfR/Fer index, has a greater diagnostic value for IDA than the use of sTfR and ferritin alone, especially in patients with inflammatory conditions. 12 However, the above ratio has not been adequately studied in infants and children, and limited studies have been performed to determine its reference range and cutoff values for ID. 10,[12][13][14][15] In Greece, the prevalence of anemia, ID, and IDA is confounded by the high prevalence of heterozygous thalassemia and has not been well-studied during the last decade in infants and toddlers.…”

“…12 However, the above ratio has not been adequately studied in infants and children, and limited studies have been performed to determine its reference range and cutoff values for ID. 10,[12][13][14][15] In Greece, the prevalence of anemia, ID, and IDA is confounded by the high prevalence of heterozygous thalassemia and has not been well-studied during the last decade in infants and toddlers. The Thrace region is one of the least developed areas of Greece, with lower income than the rest of the country.…”