epoetin-alfa and Uremia

Topics: Adult; Cardiovascular Diseases; Decision Making; Disease Progression; Epoetin Alfa; Erythropoietin; Female; Glomerulosclerosis, Focal Segmental; Hematinics; Humans; Kidney Failure, Chronic; Kidney Transplantation; Morbidity; Neoplasms; Pregnancy; Pregnancy Complications; Recombinant Proteins; Renal Dialysis; Renal Replacement Therapy; Risk Assessment; Uremia

The recommended conversion dose for changing from epoetin alfa to darbepoetin alfa is 200 units to 1 microg. However, this may result in the over treatment of uraemic anaemia.. All in-centre haemodialysis patients (n = 60) were converted from an existing subcutaneous epoetin alfa regimen to weekly intravenous darbepoetin alfa. The protocol for anaemia management included a target haemoglobin (Hb) concentration of 120-130 g/L and a ferritin of 300-600 microg/L. Patient treatments were converted from subcutaneous epoetin alfa to weekly, intravenous darbepoetin alfa at month 0, at a conversion dose of 200 units epoetin alfa to 1 microg darbepoetin.. Both Hb and ferritin concentrations remained within the target range, but darbepoetin dosages fell from 50.8 to 42.3 microg/week by month 3 (P = 0.02). The initial conversion factor of 210 units/microg rose to 275 units/microg (P = 0.01) at month 4. No difference in conversion dosage could be determined between patients who were epoetin sensitive (<200 units/kg per week) or resistant (>200 units/kg per week, P = NS). Patients were then switched to fortnightly darbepoetin alfa dosing treatments; the existing weekly dose being doubled and Hb levels fell from 125 to 110 g/L (P < 0.0001), despite an increase in the mean dose from 44.9 to 47.5 microg/week (P = 0.02).. The original dosage reduction after the switch from epoetin alfa to weekly intravenous darbepoetin alfa may offset the increased relative cost of the latter. When administered weekly and intravenously, darbepoetin alfa maintains Hb at a more favourable conversion rate than is currently recommended.

Topics: Anemia; Darbepoetin alfa; Drug Administration Schedule; Drug Costs; Epoetin Alfa; Erythropoietin; Female; Ferritins; Hemoglobins; Humans; Injections, Intravenous; Injections, Subcutaneous; Male; Middle Aged; Recombinant Proteins; Renal Dialysis; Uremia

The sudden interruption of recombinant human erythropoietin (rHuEPO) in end-stage renal disease (ESRD) patients leads to rapid anemization. The mechanisms of this phenomenon are, however, insufficiently understood. The present study examined the response to immediate rHuEPO withdrawal in dialysis patients.. 10 chronic hemodialysis (HD) patients regularly receiving rHuEPO were studied. rHuEPO was stopped and reinitiated after 7 days. Reticulocyte profile, haemoglobin and haematocrit were measured at 0, 7 and 15 days. As a complementary study, and with the purpose of analyzying whether uremia was a relevant factor, 10 non-uremic male Wistar rats were treated with rHuEPO. After two weeks, rHuEPO was withdrawn in 5 animals, and continued for 7 additional days in the remainder. The same variables than in the human study were determined.. Changes in reticulocyte subtypes from baseline to day 7 were: total 18.2 +/- 0.9 vs 14.3 +/- 1.8% (p < 0.06); high-fluorescence (HFR): 2.6 +/- 0.4 vs 0.75 +/- 0.2 (p < 0.001); medium-fluorescence (MFR): 13.0 +/- 1.1 vs 6.6 +/- 0.9% (p < 0.02); and low-fluorescence (LFR): 84.2 +/- 1.4 vs 92.7 +/- 1% (p NS). The baseline pattern was recovered upon 7 days of rHuEPO reinitiation (p NS). Mean hemoglobin and hematocrit decreased by day 14 (p < 0.02) in spite of rHuEPO reinitiation at day 7. In non-uremic rats, changes were similar to that in the ESRD patients.. rHuEPO induces changes in the reticulocyte pattern, consisting in a reduction of immature reticulocytes. These changes appear to be independent of the presence of uremia. Accordingly, complete rHuEPO withdrawal in HD patients will cause a rapidly-developing anaemia due to an alteration in the reticulocyte maturation series; therefore, sudden rHuEPO interruption should be avoided whenever is possible. As a collateral application, the specific changes described herein have potential use for detecting illegal administration of rHuEPO.

Topics: Aged; Anemia; Animals; Doping in Sports; Drug Administration Schedule; Epoetin Alfa; Erythropoiesis; Erythropoietin; Female; Hematocrit; Humans; Kidney Failure, Chronic; Male; Middle Aged; Rats; Rats, Wistar; Recombinant Proteins; Recurrence; Renal Dialysis; Reticulocyte Count; Uremia

We report the case of a woman with end-stage renal disease on maintenance hemodialysis and treated with recombinant human erythropoietin (epoetin alfa) administered subcutaneously, who developed a pure red cell aplasia secondary to the development of neutralizing antibodies anti-erythropoietin after 8 months of treatment. Despite epoetin withdrawal and immunosuppressive treatment with corticosteroids and gammaglobulins the patient still has high red blood cell transfusion requirements and undetectable plasma erythropoietin levels. Pure red cell aplasia secondary to the development of neutralizing antibodies anti-erythropoietin is a rare but severe complication associated with the use of recombinant human erythropoietin in uremic patients. In recent years, the incidence of this complication has sharply increased, specially associated with the use of epoetin alfa administered subcutaneously. For this reason, the Spanish Drug Agency has recently contraindicated treating uremic patients with epoetin alfa administered subcutaneously.

Topics: Adult; Autoantibodies; Epoetin Alfa; Erythropoietin; Female; Humans; Kidney Failure, Chronic; Recombinant Proteins; Red-Cell Aplasia, Pure; Uremia

Recent American and European guidelines recommend that epoetin therapy should be considered whenever the blood haemoglobin (Hb) level is <10-11 g/dl in dialysis patients and in pre-dialysis patients. Thus, data on the current prevalence of anaemia with respect to the degree of chronic renal insufficiency are needed in order to determine the potential indications of epoetin therapy in the pre-dialysis period.. We prospectively studied 403 consecutive ambulatory pre-dialysis patients whose serum creatinine (Scr) was 200 micro mol/l or more at their first passage at our out-patient clinic between January 1 and June 30, 1999. Hb and Scr values were determined at each visit until June 30, 2000, or until the start of maintenance dialysis. Patients had a clinical and laboratory evaluation every 2-3 months, and monthly when treated with epoetin.. The mean (+/-SD) age of patients was 60.9+/-17.2 years at presentation. The Hb level was <11 g/dl in 62% of patients with Scr > or =400 micro mol/l, and in 58% of patients with an estimated creatinine clearance (Ccr) <20 ml/min/1.73 m(2). The proportion of anaemic patients was higher for any given Ccr value in females than in males. A total of 136 patients were treated with epoetin during the observation period. At the start of epoetin, their mean Hb value was 9.5+/-0.6 g/dl and Ccr level 13.9+/-4.9 ml/min/1.73 m(2). Among the 123 patients who began maintenance dialysis therapy during the observation period, 85 (or 69%) received epoetin therapy before the start of dialysis. Their mean Hb value at the start of dialysis was 10.8+/-1 g/dl compared with 10.5+/-1.1 g/dl in the 41 dialysed patients who did not require epoetin therapy during the pre-dialysis period.. Based on the data gained in a large cohort of patients receiving regular pre-dialysis nephrological care, the proportion of subjects with a Hb level <11 g/dl may be estimated at approximately 60% when the Ccr is <20 ml/min/1.73 m(2). If the Hb level is to be maintained at no less than 11 g/dl, at least two-thirds of patients at this advanced stage of chronic renal failure should require pre-dialysis epoetin therapy.

Topics: Anemia; Creatinine; Cross-Sectional Studies; Epoetin Alfa; Erythropoietin; Female; France; Hemoglobins; Humans; Incidence; Kidney Diseases; Male; Middle Aged; Prospective Studies; Recombinant Proteins; Regression Analysis; Renal Replacement Therapy; Sex Characteristics; Uremia; White People

Chronic renal failure (CRF) is associated with prolonged bleeding time and impaired platelet adhesion and aggregation. Erythropoietin (Epo) administration improves platelet adhesion/aggregation and ameliorates prolongation of bleeding time in CRF. However, the mechanisms of improved platelet function after Epo therapy have not been fully elucidated. The present study examined the hypothesis that the improved uraemic platelet function after Epo therapy is, in part, due to correction of the platelet calcium signalling.. Rats were randomized into four groups after 5/6 nephrectomies to produce CRF. The Epo-treated CRF group received Epo, 150 U/kg, twice weekly for 6 weeks to prevent anaemia; the felodipine and Epo-treated CRF group received Epo but was kept normotensive by felodipine treatment; the placebo-treated CRF group received placebo injections and became anaemic; and the iron-deficient CRF group received Epo but was kept anaemic by dietary iron-deficiency. A group of sham-operated rats was included as normal control. Basal and thrombin-stimulated platelet cytosolic calcium ([Ca(2+)](i)) were determined using a Ca(2+)-sensitive dye (fura-2).. Platelets from placebo-treated CRF group exhibited a profound attenuation of thrombin-stimulated surge in [Ca(2+)](i), which is the final pathway of platelet activation. Long-term Epo administration led to a normalization of the thrombin-induced rise in platelet [Ca(2+)](i) in the CRF animals, independent of either haematocrit or blood pressure values. Further studies revealed that improved Ca(2+) signalling with Epo is associated with increased Ca(2+) uptake and expanded Ca(2+) stores in the platelets.. The defective Ca(2+) signalling in uraemic animals and its improvement with chronic Epo therapy provides the biochemical basis of the previously reported platelet dysfunction and prolonged bleeding time in uraemic patients and animals, and their amelioration with chronic Epo therapy.

Topics: Animals; Blood Pressure; Calcium; Calcium Signaling; Creatinine; Cytosol; Epoetin Alfa; Erythropoietin; Hematinics; Hematocrit; Humans; Kidney Failure, Chronic; Male; Platelet Aggregation; Rats; Rats, Sprague-Dawley; Recombinant Proteins; Signal Transduction; Uremia

Topics: Blood Urea Nitrogen; Bone Marrow; DNA; Epoetin Alfa; Erythropoiesis; Erythropoietin; Iron; Iron Isotopes; Metabolism; Nephrectomy; Pharmacology; Rats; Research; Spleen; Urea; Uremia

Topics: Anemia; Animals; Blood; Epoetin Alfa; Erythropoietin; Haplorhini; Infarction; Ischemia; Kidney Transplantation; Macaca mulatta; Nephrectomy; Research; Thrombosis; Transplantation, Autologous; Uremia

Topics: Anemia; Animals; Blood Volume; Bone Marrow Cells; Chromium Isotopes; Dogs; Epoetin Alfa; Erythropoiesis; Erythropoietin; Hypoxia; Iron Isotopes; Kidney; Nephrectomy; Research; Sheep; Uremia; Ureter

Topics: Blood Platelets; Blood Urea Nitrogen; Bone Marrow Examination; Epoetin Alfa; Erythropoiesis; Erythropoietin; Glomerulonephritis; Hematocrit; Hemoglobinometry; Humans; Hypoxia; Iron; Iron Isotopes; Kidney; Kidneys, Artificial; Leukocyte Count; Male; Nephrectomy; Physiology; Pyelonephritis; Radioisotopes; Radionuclide Imaging; Reticulocytes; Uremia

Topics: Animals; Epoetin Alfa; Erythrocytes; Erythropoietin; Hematopoiesis; Rabbits; Uremia; Urologic Diseases

Topics: Anemia; Animals; Epoetin Alfa; Erythrocytes; Erythropoietin; Hematopoiesis; Rats; Uremia