[Soluble transferrin receptor and erythropoietin in chronic disease anemia with or without iron deficiency]

The regulation of transferrin receptor (RTF) is related to intracellular iron stores and with the soluble receptor is present in plasma. It has already been demonstrated that in iron deficiency anemia (IDA), receptor expression increases when iron stores decrease. In anemia of chronic diseases (ACD) it is difficult to establish the real iron status because of the influence exerted by inflammatory or infectious diseases on iron metabolism. We studied 30 healthy normal subjects and 42 anemic patients (hemoglobin less than 120 g/L) affected with ACD divided into two groups with and without iron deficiency, in order to establish the diagnostic value of measuring the soluble transferrin receptor (sRTF). We correlated erythropoietin (EPO) (as an erythropoietic stimulating factor) with the decreased hemoglobin values observed in both groups. The results were analysed with an ANOVA statistic test of one way analysis of variance, and there were no significant differences in sRTF values between the ACD groups with or without iron deficiency. The ratio log EPO vs hemoglobin showed a remarkably significant inverse correlation in both groups. We can conclude that sRTF levels are within the normal reference values in these patients and are not related to organic iron. Consequently, sRTF cannot be considered a good parameter for making a diagnosis of iron deficiency in chronic diseases.