Serum Transferrin Receptor Assay in Iron-Deficiency Anemia and Anemia of Chronic Diseases

Abstract

Serum transferrin receptor (sTfR) is a biochemical parameter used for the detection of iron deficiency in situation where ferritin has limited diagnostic value owing to the present chronic disease. The serum transferrin receptor blood test may be a better indicator of iron status as it is not affected by inflammation. Accordingly, we designed this study to investigate the level and the significance of serum transferrin receptor in iron deficiency anemia (IDA) and anemia of chronic diseases (ACD) at King Abdulaziz University Hospital in Jeddah province. In this study, all samples were collected from subjects at King Abdulaziz University hospital from May to December 2008. Their ages ranged between (20-63 years). Seventy three control subjects (61 males and 12 females) and 65 anemic patients were enrolled into this study, divided into two groups: 37 (3 males and 34 females) patients with IDA and 28 (15 males and 13 females) patients with ACD. The ACD patients, were divided into sub-categories of malignant diseases (n=11), chronic inflammatory diseases(infectious and non-infectious) (n=9) and end stage renal disease (n=8). Complete blood counts (CBC), serum ferritin (SF), serum iron (SI), serum transferrin receptor (sTfR) and sTfR/log F were measured in these subjects. The results obtained for the mean of sTfR concentration among control subjects showed 2.47 ± 0.62 μg/mL (range 1-3.65 μg/mL). All patients with IDA had elevated sTfR levels (>3.65 μg/mL) and patients with ACD had normal levels of sTfR except 8 patients had high sTfR levels. The higher value in these patients suggests the presence of concurrent iron deficiency. There were no significant differences between mean of sTfR concentration and sex in control subjects and two group of patients (IDA and ACD). In IDA, the mean of sTfR concentration was 5.29 ± 0.77 μg/mL and this was significantly higher compared to control subjects and ACD patients (2.59 ± 1.72 μg/mL). A significantly higher sTfR/log F was observed in IDA (9.33 ± 8.81) compared to control subjects (1.32 ± 0.39) and ACD (1.35 ± 1.11). The mean of sTfR concentration and sTfR/log F in ACD were not significantly different from that of the control subjects. Their was no significant differences between different causes of ACD (malignant diseases, chronic inflammatory diseases (infectious and non-infectious) and end stage renal disease) and mean sTfR concentration (2.68 ± 1.80 μg/mL, 2.38 ± 1.39 μg/mL and 2.71 ± 2.11 μg/mL respectively). Therefore, we recommend using the sTfR concetration especially when the differentiation between simple IDA and ACD is problematic. In addition, it is a very useful diagnostic tool when ACD coexist with IDA.