Abstract
A multicenter collaborative study examined the usefulness of serum transferrin receptors (sTfR) as an index of iron deficiency in hemodialysis (HD) patients receiving recombinant human erythropoietin (rHuEpo).
The subjects were 80 maintenance HD patients administered rHuEpo who had not changed their dose rHuEpo or taken an iron preparation for at least the past 3 months, and who had no complications including other types of cytopenia, inflammatory diseases, hemolytic diseases, severe hyperparathyroidism or hepatic dysfunction. These patients were diagnosed with iron deficiency and administered an iron preparation intravenously. Hematology, iron kinetics and blood chemistry tests were performed and sTfR values were measured before and after administration. The effects of the iron preparation were evaluated using ΔHt, the difference between the Ht value before iron preparation administration and the maximal Ht value after 2 to 8 weeks of the administration. When ΔHt was 3% or higher, the iron preparation was considered effective and when it was less than 3%, the treatment considered was ineffective.
The effective cases (n=43) showed significantly higher sTfR values (1078±253 vs 917±241 ng/ml, p<0.005) and sTfR/Hb values (11.1±3.2 vs 8.8±2.2, μg/g, p<0.0005), and significantly lower serum ferritin (sFt) values (58±25 vs 82±36ng/ml, p<0.001) than the ineffective cases (n=37). However, the transferrin iron saturation rate (Fe-Sat), the reticulocyte count and the reticulocyte percentage did not show any differences. The ΔHt value showed better correlation with the sTfR/Hb values (r=0.672) than the sTfR, sFt and Fe-Sat values.
The diagnostic success rate for iron deficiency was the highest, 67.5% for sTfR/Hb (cut-off value: 10μg/g), followed by sTfR (1000ng/ml), sFt (50ng/ml), sFt (100ng/ml) and Fe-Sat (20%).
In conclusion, the sTfR/Hb value was considered to be the most useful index for diagnosing the necessity of administering an iron preparation to treat iron deficiency in HD patients receiving rHuEpo.
