The diagnostic role of serum transferrin receptor in patients with various anemia

Serum ferritin is known as a good tool to diagnose iron status. Recently the soluble serum transferrin receptor (sTfR) has been introduced as a promising new tool for diagnosing iron depletion. The present study was to compare the differential diagnostic values of sTfR and other related parameters in different causes of anemia.

Two hundred and nine subjects enrolled into this study were divided into 7 groups. Group A included 50 healthy controls; Group B included 54 patients with iron deficiency anemia (IDA); Group C included 34 patients with anemia of chronic disorders (ACD); Group D included 9 patients with thalassemia; Group E included 34 patients with anemia of other causes; Group F included 8 patients with thalassemia associated with IDA and Group G included 17 patients with IDA associated with ACD. Serum transferrin receptor (sTfR), ferritin, total iron-binding capacity (TIBC), unbound iron-binding capacity (UIBC) and complete blood count were measured in these subjects. In 17 patients with IDA, serum ferritin, sTfR, hemoglobin were rechecked after iron therapy for at least eight weeks and their data were compared.

sTfR could differentiate IDA from the healthy and ACD, but was unable to differentiate ACD from ACD associated with IDA, nor IDA from IDA associated with ACD. Transferrin saturation, sTfR/Ferritin and sTfR/log Ferritin were the best to differentiate ACD from ACD associated with IDA. In comparison with sTfR or serum ferritin alone, sTfR/Ferritin and sTfR/log Ferritin were better to distinguish ACD from ACD associated with IDA and IDA associated with thalassemia. Serum ferritin was better to distinguish IDA from IDA associated with thalassemia, or uncomplicated IDA from other causes of anemia, but was not so good to distinguish complicated IDA from others. It was also more sensitive than sTfR to indicate the iron repletion in the patient with IDA after iron therapy.

sTfR is a new diagnostic tool to distinguish patients with anemia. Its diagnostic ability can further improve in combination with serum ferritin, transferrin saturation and other related parameters.