Age, years Letter to the Editor Nephron 1998;80:241 Serum Transferrin Receptor Level in the Diagnosis of Iron Deficiency due to Erythropoietin Treatment H. Zeki Tonbul a H. Kaya b Y. Selçuk a A. San a F. Akçay c S.B. Tekin b Departments of a Nephrology, b Hematology, and c Biochemistry, Faculty of Medicine, Atatürk University, Erzurum, Turkey H. Zeki Tonbul Department of Nephrology Faculty of Medicine, Atatürk University TR–25240 Erzurum (Turkey) Fax +90 442 2186782 ABC Fax + 41 61 306 12 34 E-Mail karger@karger.ch www.karger.com © 1998 S. Karger AG, Basel 0028–2766/98/0802–0241$15.00/0 Accessible online at: http://BioMedNet.com/karger Dear Sir, In hemodialysis patients iron deficiency frequently occurs due to recombinant hu- man erythropoietin (r-HuEPO) treatment [1]. However, the diagnosis of iron deficien- cy is not always easy in such patients [2]. It has been suggested [3] that the serum trans- ferrin receptor (s-TfR) is a sensitive quanti- tative measure of tissue iron deficiency. We examined the changes in s-TfR levels of 24 patients (12 males, 12 females) who received r-HuEPO (50–70 U/kg/dose i.v.) at the end of each dialysis session (three times a week) diagnosed as having iron deficiency anemia by routine laboratory methods (ferri- tin ! 50 Ìg/l, transferrin saturation ! 16%). These s-TfR levels were compared with those of 32 hemodialysis patients (18 fe- males, 14 males) not receiving r-HuEPO and having no iron deficiency anemia (ferritin 1 100 Ìg/l, transferrin saturation 1 20%). Also, 40 healthy volunteers (24 females, 16 males) were included in the study as a control group. Patients with a history of blood trans- fusions within the last 3 months or with any hemolysis finding were excluded from the study. Serum ferritin and s-TfR levels were measured with enzyme-linked im- munosorbent assays using monoclonal re- agents. As shown in table 1, there were no differ- ences between the groups with and without iron deficiency anemia with respect to mean age, body weight, time on hemodialysis, and hemoglobin and serum creatinine levels (p 1 0.05). For s-TfR levels, while no difference Table 1. Demographic data and biochemical characteristics of patients and controls Controls (n = 40) No iron deficiency (n = 32) Iron deficiency (n = 24) 42B11 41B12 41.5B10.8 Body weight, kg 66.3B8.9 65B10 64.6B9.3 Time on dialysis, months – 12.6B4.8 10.8B4.7 Serum creatinine, Ìmol/l 106B26 795B115 a 822B124 a Hemoglobin, g/dl 13.5B8.1 9.1B0.7 a 9.1B1.0 a Mean corpuscular volume, fl 88.9B4.0 83B3.8 a 78.3B2.4 a, b Serum iron, Ìg/dl 86.1B23.2 51B7.3 a 34.4B11 a, b Transferrin saturation, % 29.5B4.3 24B2 a 9.2B3.2 a, b Total iron-binding capacity, Ìg/dl 290B53 213B33 a 376B46 a, b Ferritin, Ìg/l 83.1B16.4 186.5B70 a 22.1B12.8 a, b s-TfR, mg/l 5.53B1.46 5.50B1.47 14.6B3.15 a, b a p ! 0.001 as compared with the control group. b p ! 0.001 as compared with the group having no iron deficiency anemia. was present between controls and patients with no iron deficiency (p 1 0.05), the iron deficiency group had higher s-TfR values (p ! 0.001). Besides, there was an inverse correlation between hemoglobin and s-TfR levels in the patients with iron deficiency anemia (r = –0.85, p ! 0.0001). We reached the conclusion that measure- ment of the s-TfR level may be useful in patients with iron deficiency anemia under- going hemodialysis and receiving r-HuEPO when no decision could be made by means of other routine laboratory analysis. OOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO References 1 Macdougall IC: Poor response to erythropoie- tin: Practical guidelines on investigation and management. Nephrol Dial Transplant 1995; 10:607–614. 2 Macdougall IC: How to get the best out of r-HuEPO. Nephrol Dial Transplant 1995;10: 85–98. 3 Skikne BS, Flowers CH, Cook JD: Serum trans- ferrin receptor. A quantitative measure of tis- sue iron deficiency. Blood 1990;9:1870–1876. Downloaded by: Freie Universität Berlin 149.126.78.65 - 7/1/2015 5:05:47 PM