Changes of endogenous erythropoietin level and iron status during a 30-month hemodialysis treatment of a group of patients.

In our earlier paper we found that among 50 hemodialysis patients (HD pts) 48% (24 pts) control anemia with hemoglobin (Hb) concentration >9.5 g/dl and hematocrit (Hct) >30% without recombinant human erythropoietin (rHuEpo) therapy. These HD pts had significantly higher mean endogenous erythropoietin (eEpo) level and lower iron reserves (IR) than HD pts who need rHuEpo therapy. The aim of this study was to judge whether the possibility to control anemia in pts not requiring rHuEpo therapy changes during a 30-month HD treatment. Serum eEpo and ferritin were measured every 6 months. After 30 months of HD treatment 18 pts remained in this group--5 pts died, 1 underwent transplantation. During the study period 4/18 pts permanently had a very low level of eEpo (under detection limit), 7/18 had the level of eEpo within normal range for healthy control, 7/18 pts had a high level of eEpo (up to 3 times higher than the mean for healthy control). Pts who had the highest level of eEpo had the lowest IR. After 30 months IR were significantly lower than at the beginning of observation (292 +/- 87 vs 143 +/- 127 mg). Important negative correlation between eEpo and IR was observed throughout the whole period of study: r = -0.4820, p < 0.02 at the start of the study, and r = -0.6126, p < 0.007 after 30 months of treatment. The study shows that the possibility to control anemia in pts not treated with rHuEpo did not change significantly during 30 months of HD treatment. Endogenous Epo level in HD pts not treated with rHuEpo varied between different pts: it was permanently low in some pts, permanently high in others and stayed normal in remaining pts.