Analysis index

1 ml serum
1 ml heparin plasma
(Stability in serum at 4 °C – 8 °C: 8 days)

0,76 mg/l – 1,76 mg/l

Clarification of unclear anemias, especially in case of chronic inflammatory illnesses.

The soluble transferrin receptor (sTfR), which is detectable in the serum, is a fragment of the membrane-bound intact TfR, its concentration correlates with the mass of erythropoietic cells and the number of receptors on their surface. In contrast to ferritin, sTfR is not influenced by an acute phase reaction or an acute liver function disorder. TfR expression on the cell increases (sTfR increase is detectable after consumption of the iron reservoirs but before a significant drop in the hemoglobin concentration is measurable) in case of iron deficiency or hyper-proliferative diseases such as thalassemia major, autoimmune hemolytic anemias, polycythemia and others. The ferritin index is inversely related to the iron status. It is an iron supply indicator to the erythropoiesis and shows a better correlation to iron deficiency than the isolated determination of ferritin and sTfR.

Ferritin index = sTfR concentration/log ferritin concentration (reference range: 0,38 – 1,54)