Analytical and clinical implications of soluble transferrin receptors in serum

In this study the analytical performances of two recently introduced assays for soluble transferrin receptors in serum were tested. The Ramco transferrin assay was compared with the Eurogenetics assay. In a small clinical study serum samples from patients with anaemia of chronic disease, iron deficiency and myelodysplastic syndrome were analysed, as well as sera from healthy volunteers. The analytical performances of the Ramco assay were found to be acceptable. In the Eurogenetics test however, inter-assay imprecision and the end of run drift were unacceptably high. We were able to confirm that in patients with uncomplicated iron deficiency the concentration of soluble transferrin receptors is higher than in healthy volunteers. In cases of anaemia of chronic and inflammatory disease, the levels of soluble transferrin receptors in serum are slightly, but not significantly, higher than in normal subjects. Measurement of soluble transferrin receptors in serum provides a good differentiation between anaemia of chronic disease and iron deficiency.