Percentile estimates for transferrin receptor in normal infants 9-15 mo of age

Abstract

To establish percentile estimates of transferrin receptor (TfR) for healthy infants, plasma TfR was measured in 485 healthy infants 9-15 mo of age from Edmonton, Toronto, Montreal, and Halifax. Education and income of the sample families were reflective of the average family based on the 1991 census estimates. The mean (+/-SD) plasma TfR concentration was 4.4 +/- 1.1 mg/L. As expected in the infant population, there were no differences in TfR concentrations as a result of sex, and within this small age range there was no significant change across age. Furthermore, the TfR concentration in plasma was not associated with hemoglobin, serum ferritin, or free erythrocyte protoporphyrin. TfR has been shown to be a sensitive, quantitative measure of tissue iron deficiency not affected by inflammation and is potentially important in the diagnosis of iron deficiency, but there is a lack of normative data, particularly in infants, who are at highest risk of iron deficiency. If TfR proves useful in the diagnosis of iron deficiency, the current data will be useful as a reference standard for healthy infants.

Disparity of serum transferrin receptor measurements among different assay methods

“…For example, we recently reported (Yeung & Zlotkin, 1997) the mean TfR value for normal healthy infants 9± 15 months of age to be 4.4 mg/l, using our Lab assay. Values above 7 mg/l were above the 95th centile, considered to be indicative of iron de®ciency.…”

“…The publication of normative centile estimates for TfR in infants based on the Lab assay (Yeung & Zlotkin, 1997) has increased the likelihood that laboratory values for TfR will be misinterpreted. TfR concentrations above the published normal range may indicate iron de®ciency, but only when our Lab assay is used for the measurement.…”

“…In healthy adults, the Ramco assay reports a normal TfR range of 2.9± 8.3 mg/l; the Quantikine assay reports 0.85±3.05 mg/l. An indirect enzyme-linked immunosorbent assay (ELISA) developed in our laboratory (`Lab') provides a TfR range of 2.4±8.0 mg/l in healthy infants (Yeung & Zlotkin, 1997).…”

Demi̇r Eksi̇kli̇ği̇ Tanisinda Serum Transferri̇n Reseptörü

“…Kanada'dan bildirilen 485 sağlıklı bebekte sTfR düzeylerinin ölçüldüğü bir çalışmada; sTfR'nün erişkin hastalarda bildirildiği şekilde (8,9,10,11), bizim çalışmamızda da olduğu gibi, yaş ve cinsle değişmediği, enfeksiyondan etkilenmediği, doku demir eksikliğinin duyarlı, kantitatif bir ölçümü olduğu belirtilmektedir (18). Tayland'da 1861 anemik çocukta; Hb, ferritin ve sTfR ölçülmüş, anemi varken sTfR'nün yükseldiği, ferritinin ise yükselmediği, enfeksiyon varlığında ferritinin tanısal değerinin az olduğu, sTfR'nün en iyi Hb ile korelasyon gösterdiği vurgulanmıştır (19).…”

Transferrin receptor in children and its correlation with iron status and types of milk consumption

“…Some studies have described iron status and the mean concentrations of TfR at various ages (4,(7)(8)(9)(10). Unfortunately, the methods used differ widely and yield different concentrations.…”