Introduction In recent years, determination of soluble transferrin receptor levels has
been emerging as a test that can reliably indicate iron deficiency in various states, and
that is non-invasive and easy to use.
Objective To determine reference values of sTfR concentrations in serums in our
population, to examine the reliability of the method in the diagnosis of anemia due to
iron deficiency and associated iron deficiency in anemia accompanying chronic
illnesses, to identify possible limitations of the test in certain conditions, to examine the
value of combinations with other tests in the diagnosis of mentioned anemia types.
Methods The prospective research included 86 patients with anemia: 46 patients with
iron-deficiency anemia, and 40 patients with anemia of a chronic disease. The control
group consisted of 40 healthy persons aging over 18. It was performed at the Clinic of
Hematology, while laboratory tests were conducted in the Immunology and
Biochemistry Laboratory of the Clinical Center Niš. Values of complete blood count,
iron and iron-binding capacity in serum, ferritin and soluble transferrin receptors were
determined.
Results Ferritin values were reduced in 76.1% of patients, while higher levels of
soluble transferrin receptors appeared in 100% of patients with anemia due to iron
deficiency. In patients with reduced serum ferritin levels, sTfR/log ferritin index was
statistically significantly higher than in patients in whom ferritin concentration was in
the normal range (p <0.001). ROC analysis of patients with anemia due to iron
deficiency showed that sTfR/log ferritin index (AUC 0.992) and levels of soluble
transferrin receptors (AUC 0.986) occupied the largest area under the curve, thus
representing the best diagnostic markers for these patients. The best diagnostic
parameter for detecting iron deficiency in patients with anemia of a chronic disease by
ROC analysis is the sTfR/log ferritin index (AUC 0.770).
Conclusion Soluble transferrin receptors are useful in the diagnosis of anemia due to
iron deficiency, especially when ferritin values are not reduced. The calculation of
sTfR/log ferritin index is even more reliable. In patients with anemia of a chronic
disease, the associated iron deficiency could be best indicated by sTfR/log ferritin
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