Evaluation of diagnostic efficacy of serum sTfR assay in iron-deficiency anemia and Beta-thalassemia trait in Shafa hospital, Ahvaz, Iran 2010.

BACKGROUND AND

OBJECTIVES

Soluble form of transferrin receptor (TFR) called soluble TFR (sTfR) is shed mainly from the erythroid precursors and with a slower rate from other tissues into the plasma. This process of release is intensified in situations characterized with a some degree of erythroid hyperplasia or body iron stores depletion, such as seen in beta-thalassemia trait (betaTT) and iron-deficiency anemia (IDA), respectively. Therefore, the employement of sTfR assay as a diagnostic tool for differentiating IDA from betaTT in case of co-existence of these two clinical entities seems to be questionable. In this work we decided to study the above-mentioned dilemma in our geographical area, south of Iran.

MATERIALS AND

METHODS

Whole blood (5 ml) and serum samples (2 ml) were collected from 30 patients with IDA, 30 individuals with betaTT and 30 apparently healthy cases as control group. Complete blood count (CBC) was done by blood analyzer and serum iron, serum ferritin and serum sTfR were assayed by biochemical, immunological (chemiluminescence) and Elisa Kit, respectively.

RESULTS

Serum ferritin concentration in IDA group was significantly lower than the concentration seen in betaTT: 6.93 ± 4.16 vs 47.40+/=32.33 microg/ml. The findings for sTfR serum concentration in IDA group (3.25+/=1.60 microg/ml) and betaTT group (1.86+/=0.36 microg/ml) showed a significant difference between IDA and the control group (p < 0.001), with some overlap between IDA and betaTT groups. Serum ferritin concentration and serum sTfR concentration in the control group were (65.60 ± 58.53 microg/dl) and (1.51+/=0.22 microg/ml), respectively. The sTfR/ferritin ratio clearly showed a diagnostic superiority to ferritin assay in IDA diagnosis.

CONCLUSIONS

The observed overlap in serum stfR concentrations between IDA and betaTT groups makes the sTfR assay unefficient tool for a differential diagnosis between IDA and betaTT in the early stages of IDA. An higher diagnostic potential was observed in the advanced stage of iron deficiency anemia. Calculated ratio of serum sTfR/ferritin showed the diagnostic superiority to ferritin assay alone in IDA diagnosis.