Effectiveness of Subcutaneous Low-Dose Erythropoietin in Patients with Chronic Renal Failure despite Functional Iron Deficiency

Dr. Pier Luigi Bedani, Division of Nephrology, S. Anna Hospital, I-44 100 Ferrara (Italy) Dear Sir, There are many causes of decreased responsiveness to erythropoietin (EPO) in patients with chronic renal failure. The commonest is insufficient iron to meet the demands of increased erythrocyte production [1]· However, there are patients who respond to EPO with a rapid increment of haemoglobin despite the lowest ferritin levels [2]. We report on 4 patients with anaemia due to chronic renal failure, who responded favourably to weekly subcutaneous low-dose EPO despite functional iron deficiency. The patients (4 females; mean age: 47 ± 21 years; serum basal creatinine ranged between 476 and 724 μmol/l) participated in a study made in various hospitals assessing the effect of EPO on anaemia due to progressive renal failure. Inclusion criteria for the study were a minimum age of 18 years irrespective of sex, a serum creatinine level between 200 and 800 μmol/l and serum haemoglobin concentration of less than 90 g/l. After 2 weeks of prophylactic oral iron supplementation (40 mg/day of elemental iron), all patients were treated with EPO (Eprex, Cilag) 100 U/ kg/week by the subcutaneous route. The target haemoglobin concentration for this study was set at 110 g/l, and after having arrived at this level the EPO dose was adjusted to maintain it at a stable value. Before treatment, all but 1 patient had normal serum ferritin concentrations (54, 61, 55 and 8 ng/ml, respectively; normal range 15-300 ng/ml), while calculated percentage saturation of Transferrin saturation Ferritin Haemoglobin Fig. 1. Behaviour of serum ferritin levels, percentage of transferrin saturation and haemoglobin concentrations in 4 patients treated over 24 weeks with EPO.