Introduction: The objective of this study was to assess the clinical significance of soluble transferrin receptor (sTfR) in hypochromic microcytic anaemia.

Methods: Serum sTfR was determined on 91 blood samples with haemoglobin less than 110 g/L and MCV less than 76 fl or MCH less than 27.0 pg. The samples were classified as iron deficiency anaemia (IDA), anaemia of chronic disease (ACD) and thalassaemia. ACD was further divided into groups 1 and 2, based on the serum ferritin level.

Results: The sTfR level in the control was 1.53+/-0.8 mg/L. In IDA, the sTfR level was 5.53+/-8.76 mg/L and this was significantly higher compared with the control (p-value is less than 0.0001). sTfR levels in ACD (3.32+/-3.94 mg/L) and the thalassaemia group(1.64+/-1.02 mg/L) were not significantly different from that of the control (p-value is more than 0.05). In ACD, the sTfR level in group 1 was significantly higher when compared with the control (p-value is less than 0.001) and group 2 (p-value is less than 0.01). A significantly higher sTfR/ferritin ratio was observed in IDA (2,368.98+/-7,236.4 microg/microg) compared to the control (37.6+/-43.7 microg/microg) (p-value is less than 0.001). No significant difference was noted between ACD, thalassaemia and control (p-value is greater than 0.05). sTfR/ferritin ratio was significantly higher in group 1 of ACD when compared with that of control and group 2 (p-value is less than 0.001).

Conclusion: Serum sTfR and sTfR/ferritin ratio are useful parameters in hypochromic microcytic anaemia to diagnose iron deficiency particularly when associated with chronic inflammation. sTfR can be done selectively in ACD patients when ferritin levels are more than 60 microg/L and there is a diagnostic dilemma. If sTfR level is raised, a trial of iron therapy is suggested for these patients.