The reference limits and cut‐off value for serum soluble transferrin receptors for diagnosing iron deficiency in infants

Abstract

Serum soluble transferrin receptors (sTfR) concentration is a useful test in the diagnosis of childhood iron deficiency (ID). The aims of this study were to establish reference limits and to evaluate the diagnostic characteristics of sTfR in the diagnosis of ID in infants aged 9-12 months. In addition to mean erythrocyte cell volume, haemoglobin and ferritin measurements, sTfR concentration was measured in 179 healthy children in Estonia using the IDeA and Tina-quant methods. Using the ID criteria of ferritin <10 microg/l, subjects were divided into healthy (n = 146) and ID (n = 33) groups. The reference limits (5th and 95th percentile) were calculated in the study group. We used receiver operating characteristic curves to find out the cut-off values for the best diagnostic characteristics. The reference limits for sTfR were 1.5-2.7 mg/l in the IDeA method and 4.1-7.8 mg/l in the Tina-quant) method. The methods had poor agreement, the mean ratio with 95% limits of agreement was 2.9 (2.4-3.6). The best cut-off value in order to identify ID by hypoferritinaemia in this population is an sTfR level > 2.4 mg/l in the IDeA (sensitivity 84%, specificity 94%) and an sTfR level > 7.4 mg/l in the Tina-quant (sensitivity 80%, specificity 92%). We conclude that sTfR concentration is an efficient tool in the diagnosis of ID, but that every method needs its own cut-off value.

The Content of Reticulocyte Hemoglobin and Serum Concentration of the Soluble Transferrin Receptor for Diagnostics of Anemia in Chronically Hemodialyzed Patients

“…The results of research conducted by other authors confirm the usefulness of an assessment of soluble transferrin receptor in diagnosing iron deficiencies [18][19][20][21]. Those authors recommend sTfR as a reliable index which makes it possible to assess the assimilability of iron during the treatment of its systemic deficiencies [19].…”

Improved differential diagnosis of anemia of chronic disease and iron deficiency anemia: A prospective multicenter evaluation of soluble transferrin receptor and the sTfR/log ferritin index

“…However, sTfR assays from different manufacturers have not been standardized and sTfR analytical methods show poor agreement [16,[20][21][22][23]; specific cutoff values for both sTfR and the sTfR Index should be determined for each method. Cutoffs presented in this report apply only to the Access sTfR assay and sTfR Index.…”

Iron Status and Systemic Inflammation, but Not Gut Inflammation, Strongly Predict Gender-Specific Concentrations of Serum Hepcidin in Infants in Rural Kenya

“…The lower limit of detection (LLOD) for CRP was 0.9 mg/L. The following cut-offs were used: (a) anemia: Hb <110 g/L for infants and <120 g/L for adult women [16], (b) iron deficiency: SF <12 ng/mL [16] or sTfR ≥7.4 mg/L [17], and (c) elevated CRP: ≥4.1 mg/L (manufacturer’s reference range).…”