Comparison between Soluble Transferrin Receptor, Serum Ferritin and Trans-ferrin Saturation in Chronic Renal Failure Patients

Cho, Hee Soon; Lee, Chae Hoon; Kim, Kyung Dong

Abstract

BACKGROUND
In chronic renal failure (CRF) patients, iron deficiency is a common problem and a primary cause of resistance to recombinant human erythropoietin (rHuEPO) therapy. Serum ferritin and transferrin saturation (TS) are most commonly used parameters of iron status in CRF patients but may be influenced by the presence of inflammation and malnutrition. Recently soluble transfer-rin receptor (sTfR) has been advocated as a useful parameter of iron deficiency. We evaluated sTfR as an iron deficient marker in CRF patients. METHODS: Included in this study were 73 CRF patients, 30 uncomplicated iron deficiency anemia (IDA) patients, and 55 normal control. Serum sTfR, serum ferritin, TS, and complete blood count were measured. The CRF patients were classified as absolute iron deficient, functional iron deficient, non-iron deficient, and iron overload groups according to National Kidney Foundation Kidney Disease and Dialysis Outcome Quality Initiative (NKF-K/DOQI) guideline. RESULTS: The sTfR concentrations were significantly higher in uncomplicated IDA patients (3.9 +/-1.5 mg/L) and significantly lower in CRF patients (1.1 +/-0.4 mg/L) than in normal controls (1.4 +/-0.4mg/L). In uncomplicated IDA patients, sTfR was inversely correlated with MCV, MCH, and MCHC. In CRF patients, sTfR had a weak inverse correlation with TS and MCHC, but not significantly different between the four groups. The sTfR was not significantly different between the CRF patients with the normal CRP and those with an increased CRP. CONCLUSIONS: The sTfR is useful for diagnosis of uncomplicated IDA, but not for the detection of iron deficiency in CRF patients. Further studies are needed for the evaluation of sTfR as an erythro-poietic marker with rHuEPO therapy.