The relation between chemically measured total iron-binding capacity concentrations and immunologically measured transferrin concentrations in human serum

Abstract

We sought to determine if serum total iron-binding capacity (TIBC) is equivalent to serum transferrin (TRF) so that a low-cost colorimetric chemical assay for unsaturated iron-binding capacity (UIBC) could be substituted for a high-cost immunologic assay for TRF. Our study design included independent and blinded measurements of UIBC, serum iron, and TRF concentrations in human serum samples. Data from five independent correlation studies carried out at three different Quest Diagnostics laboratories were combined into one data set containing 570 paired results for TIBC and TRF. r2 was 0.941 when three outliers were eliminated from the 570-sample data set. Scatter about the regression line was fully accounted for by the CVs for the TIBC and TRF assays. When each test is measured precisely and without bias, the ratio of TIBC (μmol/L) to TRF (g/L) in SI units is close to the theoretically expected value of 25.0.

Population screening for hemochromatosis: A comparison of unbound iron-binding capacity, transferrin saturation, and C282Y genotyping in 5,211 voluntary blood donors

“…Other available methods for the determination of TS include the measurement of total iron binding capacity (TIBC) or serum transferrin. 4 TS was calculated as serum iron/serum iron ϩ UIBC. C282Y genotyping was done by Rsa1 restriction enzyme digestion as previously described.…”

A simple assay for measurement of ovotransferrin – a marker of inflammation and infection in birds

“…This assay measures total iron-binding capacity -the maximum amount of iron necessary to saturate all the ovotransferrin in a sample. This correlates very well with ovotransferrin concentration, as determined by comparison with immunological measurement of serum transferrin (Gambino et al 1997;Yamanishi et al 2002). A similar version of the assay has been used previously to measure concentrations of ovotransferrin in egg albumen (Shawkey et al 2008;D'Alba et al 2010).…”

Screening for hemochromatosis

“…TIBC saturation may show considerable bias with respect to the transferrin saturation due to inadequate standardization. 10 If a screening program based on phenotype were undertaken, the present choices for the initial screening strategy are estimation of transferrin saturation, estimation of TIBC saturation, or estimation of UIBC. The investigators claim that UIBC was a considerably less expensive test than TIBC saturation and performed better than TIBC saturation in identifying C282Y homozygotes.…”