Serum transferrin receptor: a quantitative measure of tissue iron deficiency

Abstract

This study was undertaken to evaluate the role of serum transferrin receptor measurements in the assessment of iron status. Repeated phlebotomies were performed in 14 normal volunteer subjects to obtain varying degrees of iron deficiency. Serial measurements of serum iron, total iron-binding capacity, mean cell volume (MCV), free erythrocyte protoporphyrin (FEP), red cell mean index, serum ferritin, and serum transferrin receptor were performed throughout the phlebotomy program. There was no change in receptor levels during the phase of storage iron depletion. When the serum ferritin level reached subnormal values there was an increase in serum receptor levels, which continued throughout the phlebotomy program. Functional iron deficiency was defined as a reduction in body iron beyond the point of depleted iron stores. The serum receptor level was a more sensitive and reliable guide to the degree of functional iron deficiency than either the FEP or MCV. Our studies indicate that the serum receptor measurement is of particular value in identifying mild iron deficiency of recent onset. The iron status of a population can be fully assessed by using serum ferritin as a measure of iron stores, serum receptor as a measure of mild tissue iron deficiency, and hemoglobin concentration as a measure of advanced iron deficiency.

Quantification of body iron and iron absorption in the REDS‐IIDonor Iron Status Evaluation (RISE) study

“…In this study, we considered TBI as reflecting a storage compartment and a functional compartment consisting of circulating Hgb (measured) and marrow and tissue iron (not measured). Storage iron was measured using the methodology developed by Skikne and colleagues and Cook and coworkers, as expressed by the following formula: …”

“…Quantitative estimates of body iron stores have been used to characterize iron deficiency in epidemiologic studies . In 1990, a simplified index was developed based on the relationship between soluble transferrin receptor (sTfR) and ferritin and correlation of the log(sTfR/ferritin) with iron depletion by serial quantitative phlebotomy . This technique measures the amount of iron available for Hgb synthesis, or “mobilizable” iron stores .…”

Iron status in pregnant women: which measurements are valid?

“…Although low serum ferritin is a reliable index of iron deficiency, in the presence of infection, normal or raised levels may be seen in deficient subjects (Lipschitz et al, 1974). More recently the measurement of serum transferrin receptors and the serum transferrin receptor:ferritin ratio have been proposed as new indices of iron deficiency (Flowers et al, 1989;Skikne et al, 1990b). Receptor synthesis is up-regulated in iron-deprived tissues.…”

Body iron stores in relation to growth and pubertal maturation in healthy boys

“…Serum ferritin concentrations were determined by a two-site chemiluminometric immunoassay with an automatic analyser (Ciba Corning ACS:180, Ciba Corp., Halstead, U.K.). The transferrin receptor-ferritin ratio was calculated and iron stores in mg per kg were estimated from this ratio (Skikne et al, 1990). The amount of circulating red blood cell mass was calculated from the formula: haematocrit value 2 blood volume (64 ml/kg) 2 body weight.…”

“…By incorporating the changes in iron stores as reflected by serum ferritin and the changes in functional iron as reflected by the serum transferrin receptor, the ratio of the serum transferrin receptor to ferritin provides a single parameter that encompasses a broad range of iron status. Skikne et al (1990) have calculated the amount of iron removed by phlebotomy and estimated the corresponding iron stores, using such ratios.…”