Recombinant human erythropoietin corrects anaemia during the first weeks after renal transplantation: a randomized prospective study

BACKGROUND.: Studies on the effect of recombinant human erythropoietin (rHuEpo)on haematopoiesis in patients with kidney transplants, havebeen limited to progressive chronic graft failure, late aftertransplantation. In the present prospective randomized study,the efficacy of rHuEpo in the correction of anaemia during thefirst weeks after renal transplantation (RTP) was evaluated. METHODS.: Patients were allocated to either an Epo-(n=14) or a non-Epo-treatedgroup (n=15). Epo (150 U/kg.week s.c.) was started at a haematocrit(Hct) <30% and was increased at weekly intervals by 30 U/kg.week,as long as Hct remained <25%. RESULTS.: In the Epo group, Hct increased from a nadir of 22±4%2 weeks after RTP to 30±4% at week 4 and to 36±4%at week 6 (P<0.001 and P<0.0001 respectively vs week 2).Corresponding values in the non-Epo group were 25±6%,28±6% (P=NS) and 32±6% (P<0.05 vs week 2) (overallevolution Epo vs non-Epo: P=0.038 by variance analysis). Thedifferences in Hct between the Epo and non Epo group were evenmore marked in patients without major complications (varianceanalysis P=0.009). The Epotreated patients required fewer post-surgicalblood transfusions (0.005 vs 0.014/days follow-up, P<0.05),in spite of greater post-surgical blood losses, especially atday 1 (P<0.05) and the presence of more major complications(7 vs 4) and a higher number of ganciclo vir-treated patients(4 vs 0; P<0.05). The maximum Epo dose after RTP was >2xhigher than the one required before RTP (197.1±45.1 vs85.0±76.0 U/kg.week; P<0.05). CONCLUSIONS.: It is concluded that rHuEpo during the first weeks after RTPis of benefit in the correction of the Hct in the early post-surgicalperiod, in spite of relative Epo resistance.     

Beneficial influence of recombinant human erythropoietin therapy on the rate of progression of chronic renal failure in predialysis patients.

BACKGROUND: Partial correction of anaemia with recombinant human erythropoietin (rHuEpo) has been shown to markedly improve the general condition and quality of life of predialysis patients, but the effects of rHuEpo therapy on blood pressure and the rate of progression of chronic renal failure (CRF) are still disputed. In particular, no study evaluated the time duration until the start of maintenance dialysis in treated patients, compared to untreated predialysis patients. METHODS: We retrospectively evaluated the rate of decline of creatinine clearance (Delta Ccr) and the duration of the predialysis period in 20 patients with advanced CRF treated with rHuEpo (Epo+ group), and in 43 patients with a similar degree of CRF but with less marked, asymptomatic anaemia, not requiring rHuEpo therapy (Epo- group). All patients were submitted to identical clinical and laboratory surveillance. All received similar oral supplementation with B(6), B(9), and B(12) vitamins and oral iron supplementation. Maintenance dose of subcutaneous epoetin was 54.3+/-16.5 U/kg/week (median dose 3300 U/week). RESULTS: Initial and final haemoglobin (Hb) levels were 8.8+/-0.7 and 11.3+/-0.9 g/dl in the Epo+ group, vs 10.9+/-1.2 and 9.5+/-0.9 g/dl in the Epo- group. In the Epo+ group, Delta Ccr declined from 0.36+/-0.16 during the preceding 24 months to 0.26+/-0.15 ml/min/ 1.73 m(2)/month after the start of rHuEpo therapy (P<0.05). No significant variation was observed in the Epo- group. Time duration until the start of dialysis was 16.2+/-11.9 in the Epo+ group, compared to 10.6+/-6.1 months in the Epo- group (P<0.01). Slowing of progression was observed in 10 Epo+ patients, whereas no significant variation in Delta Ccr occurred in the other 10. There was no difference in previous Delta Ccr rate, nor in Hb or blood pressure levels while on rHuEpo therapy between the two subgroups. CONCLUSIONS: Our study affords conclusive evidence that rHuEpo therapy did not result in accelerated progression of CRF in any treated predialysis patients, nor deleterious increase in blood pressure, but instead resulted in significant slowing of progression and substantial retardation of maintenance dialysis. Such encouraging results remain to be validated in a large prospective, randomized study.     

Enhanced platelet reactivity with erythropoietin but not following transfusion in dialysis patients

Although the haemostatic defects that occur in uraemia are complex,a major factor is the anaemia of renal failure. This may nowbe corrected by recombinant human erythropoietin (rHuEpo) therapyrather than by repeated blood transfusion. Platelet reactivityto shear stress and collagen was measured using non-anticoagulatedblood to study the effect of erythropoietin or blood transfusionon platelet function. Twenty dialysis patients were commencedon 25–50 U/kg rHuEpo twice weekly. The dose was adjustedafter 3 months to maintain target Hb 10–10.5 g/dl. A further15 patients were studied before and 10–12 days after receivingblood transfusion. Baseline platelet reactivity was subnormalin both groups versus control (P<0.0001). In the rHuEpo group,a significant increase in platelet reactivity was observed at2 months (P<0.005) which disappeared at 3 months. This wasnot related to the increase in Hb (7.3±0.3 to 10.2±0.3g/dl, P<0.0001). There was no change in platelet reactivityafter transfusion, despite an increase in Hb (6.2±0.2to 8.8±0.2 g/dl, P<0.0001) similar to that occurringin the rHuEpo group. We conclude that after rHuEpo therapy butnot after transfusion a transient increase in platelet reactivityoccurs which is dissociated from changes in platelet and redcell numbers.     

The effects of ACE inhibitor treatment and ACE gene polymorphism on erythropoiesis in chronic hemodialysis patients

Aggravation of anemia in chronic renal failure patients by angiotensin-converting enzyme inhibitors (ACEIs) has been attributed to the inhibition of angiotensin II which facilitates erythropoietin(Epo) production. This study was aimed at evaluating whether ACEIs aggravate anemia in maintenance hemodialysis patients and to investigate the influence of ACE gene polymorphism on erythropoiesis in these patients. Ninety-one hemodialysis patients were divided into 2 groups, based on whether or not they were administered ACEIs, into the ACEI group(n = 24) and the non-ACEI group(n = 67), and comparisons were made of the doses of recombinant human Epo(rHuEpo) administered, the hematocrit(Hct) and the plasma Epo concentrations. Among the patients in the non-ACEI group, only 17 did not receive rHuEpo, while all of the patients in the ACEI group received rHuEpo. The average dose of rHuEpo was 102.7 +/- 45.4 IU/kg/week in the ACEI group and 57.8 +/- 55 IU/kg/week in the non-ACEI group and the difference between the two groups was statistically significant. A statistically significant difference in the Hct was also observed between the two groups: the mean Hct in the ACEI group was 28.7 +/- 2.9% while that in the non-ACEI group was 31.1 +/- 3.7%. The plasma Epo concentrations were significantly lower in the ACEI group than in the non-ACEI group. No significant differences in the rHuEpo dose and Hct were observed between the three ACE genotype classes in either the ACEI or the non-ACEI group, however, there was a significant difference among the three genotypes in the non-ACEI group in regard to the plasma Epo concentrations; patients with the DD genotype had higher concentrations than those with the DI or II genotypes. These data suggest that anemia in maintenance hemodialysis patients is worsened by ACEIs as a result of the suppression of Epo production. Although it has been suggested that the endogenous Epo concentrations in maintenance hemodialysis patients are associated with ACE gene polymorphism, no significant influence of the ACE genotype on the rHuEpo dose or Hct was evident. Therefore, it is possible that exacerbation of anemia by ACEIs in the patients receiving rHuEpo is a result of an inhibited bone marrow response to Epo.     

Hemodynamic effects of anemia correction by recombinant human erythropoietin in predialysis patients with renal failure

Most patients with chronic renal failure have anemia, which can be corrected by recombinant human erythropoietin (rHuEpo) treatment. Increase in arterial pressure (AP) was reported in some studies and was related to higher systemic vascular resistance induced either by the rise of erythrocyte mass or the change in various endogenous vasopressors, including the direct action of rHuEpo itself. We investigated the effect of rHuEpo treatment on hemodynamic variables, including small and large arterial compliance in 20 patients with chronic renal failure who were not receiving dialysis (CCT 29 +/- 12 mL/min), with Hb levels of 40.4 +/- 0.58 g/dL. They were treated with 2,000 units intravenously followed by 80 to 120 s/c units/kg/body weight, with dosage titration according to Hb level. Noninvasive hemodynamic evaluation was performed before the first rHuEpo treatment, 30 min after the first IV rHuEpo administration and at least 3 months later when target hemoglobin (Hb) and hematocrit (Hct) were reached. No rise in AP occurred after rHuEpo administration either short term or long term. The significant hemodynamic changes were a fall in pulse pressure and a rise in large artery compliance, with no change in small artery compliance after 3 months of rHuEpo treatment when Hb and Hct levels were corrected. These findings show improvement in arterial stiffness when Hb is corrected with rHuEpo treatment.     

Influence of long-term recombinant human erythropoietin (rHuEpo) therapy on plasma leptin and neuropeptide Y concentration in haemodialysed uraemic patients

Background: In patients with chronic renal failure, rHuEpo therapy ameliorates anaemia and improves wellbeing, exercise tolerance, and appetite. Both leptin and neuropeptide Y play an important role in regulation of appetite and energy balance in humans. Methods: The present study aimed to assess the influence of 12 months rHuEpo therapy on plasma leptin and neuropeptide Y concentrations in 15 haemodialysed patients (HDP) (6F, 9M; mean age 4.8±2.9 years; mean BMI 23.6±1.1 kg/m²; mean duration of HD 3.3±0.6 months) (Epo group). A second group (no-Epo group) consisted of 17 HDP (9F, 8M; mean age 44±3.2 years; mean BMI 24.3±1.0 kg/m²; mean duration of HD 2.5±0.4 months not treated with rHuEpo for 12 months. Basal plasma leptin and neuropeptide Y concentrations were estimated by RIA at the beginning and after 3, 6, 9 and 12 months of rHuEpo therapy (Epo group) or clinical observation (No-Epo group). The control group consisted of 30 healthy subjects (15 females, 15 males, mean age-38.2±1.7 years, mean BMI 24.7±0.7 kg/m²). Results: Baseline plasma leptin concentrations in HDP were higher, although statistically not significant than leptinaemia in healthy subjects. After 3, 6, and 12 months of rHuEpo therapy plasma leptin concentrations were significantly lower than at the beginning of the study. Baseline plasma neuropeptide Y concentrations in HDP did not differ significantly from controls. After 3 and 6 months of the study period plasma neuropeptide Y concentrations increased significantly in patients of both the Epo and No-Epo group. This increase was, however significantly higher in rHuEpo-treated than in untreated patients. Conclusions: (1) rHuEpo treatment in haemodialysed patients with chronic renal failure is followed by a significant decline of leptinaemia and disappearance of the physiological positive BMI/leptinaemia relationship. (2) Suppression of leptinaemia induced by rHuEpo may be of clinical relevance in haemodialysed patients with chronic renal failure.     

Erythropoietin in patients with acute renal failure and continuous veno-venous haemofiltration

Erythropoietin (Epo) is a glycoprotein hormone produced in the kidney in response to hypoxia or anaemia. In acute renal failure (ARF) anaemia also occurs and current opinion is that Epo production is depressed with inappropriately low plasma levels throughout the uraemic phase. Our study was designed to determine the excretion of Epo in patients with ARF. Fifty-nine ventilated patients were studied, 39 with ARF and continuous veno-venous haemofiltration therapy (group 1) and 13 patients with normal renal function who served as a control group (group 2). All patients with ARF were anaemic and needed a mean transfusion of 0.6 units/day. Values for vitamin B12, folic acid, serum iron and ferritin were normal. While patients with normal renal function had Epo values within the normal range, patients with ARF had significantly higher values at the onset of haemofiltration therapy. Mean Epo (mean±SEM) values on days 0–2 were 92.6±11.7 mU/ml in group 1 and 16.5±6.4 mU/ml in group 2 (p<0.0002). Epo levels declined in group 1 to 49±10.5 mU/ml on days 9 and 10 compared to 23±9.1 mU/ml in group 2 (ns). These values were maintained until the end of the observation period. No differences were seen between oliguric and non-oliguric patients. Our data show that patients with ARF have increased Epo levels at the beginning of the disease with a strong tendency to decrease, suggesting that there might be inadequate Epo levels during the course of acute renal failure.     

THE INFLUENCE OF l-CARNITINE SUPPLEMENTATION ON HEMATOCRIT AND HEMOGLOBIN LEVELS IN PATIENTS WITH END STAGE RENAL FAILURE ON CAPD

The influence of l-carnitine supplementation on hematocrit (Hct) and hemoglobin (Hb) levels, in patients suffering from end stage renal disease (ESRD) on maintenance hemodialysis, are well known from several studies. The data concerning the serum levels of carnitine, in patients with ESRD on continuous ambulatory peritoneal dialysis (CAPD) are contradictory, but most of them support that they are rather normal. In this study the effect of l-carnitine supplementation on Hct, and Hb levels were investigated in patients suffering from ESRD on CAPD. In the study 12 patients were included (5 F, 7 M), aged from 39 to 92 years old (median 65.5 years), who were on CAPD for more than 6 months (from 6 to 15 months, mean ± SD = 8.6 ± 3.6), with normal serum ferrum and ferritin levels at the beginning of the study. Two grams of l-carnitine/day per os (Superamin, Vianex Hellas), were administered in all the patients and the serum ferrum levels were tried to be kept stable, by exogenous ferrum administration, during the study period. If the Hct levels were more than 36% per month the erythropoietin (rHuEpo) dose of the patient was decreased monthly at the half dose/week. The changes of Hct, Hb, ferrum and ferritin levels, as well as the Indice de Rigidite (IR) of the erythrocytes were recorded, before and after the first, second and third month of the study period. Finally, the rHuEpo dose/patient was registered monthly before and during the study. During the observations, Hct (35.4 ± 3.3 vs. 38.1 ± 3.4, ANOVA, p < 0.03) and Hb levels (11.0 ± 1.1 vs. 11.9 ± 1, ANOVA, p < 0.01), were significantly increased. On the other hand, rHuEpo dose necessity/patient/week was decreased significantly (3833 ± 3326 vs. 1292 ± 1712, ANOVA, p < 0.01), in order to succeed the target Hct level. Furthermore, red blood cells IR also appeared to have a significant decrease (16.6 ± 7.4 vs. 13.0 ± 3.9, paired t-test, p < 0.03). Finally, the ferrum and ferritin levels were stable during the study period. It was concluded, that in patients on, CAPD the per os l-carnitine supplementation decreased, the red blood cells IR which contributes to the: (a) Increase of Hct and Hb levels and (b) decrease of the patients rHuEpo dose/week.     

The influence of l-carnitine supplementation on hematocrit and hemoglobin levels in patients with end stage renal failure on CAPD

The influence of L-carnitine supplementation on hematocrit (Hct) and hemoglobin (Hb) levels, in patients suffering from end stage renal disease (ESRD) on maintenance hemodialysis, are well known from several studies. The data concerning the serum levels of carnitine, in patients with ESRD on continuous ambulatory peritoneal dialysis (CAPD) are contradictory, but most of them support that they are rather normal. In this study the effect of L-carnitine supplementation on Hct, and Hb levels were investigated in patients suffering from ESRD on CAPD. In the study 12 patients were included (5F, 7M), aged from 39 to 92 years old (median 65.5 years), who were on CAPD for more than 6 months (from 6 to 15 months, mean +/- SD = 8.6 +/- 3.6), with normal serum ferrum and ferritin levels at the beginning of the study. Two grams of L-carnitine/ day per os (Superamin, Vianex Hellas), were administered in all the patients and the serum ferrum levels were tried to be kept stable, by exogenous ferrum administration, during the study period. If the Hct levels were more than 36% per month the erythropoietin (rHuEpo) dose of the patient was decreased monthly at the half dose/week. The changes of Hct, Hb, ferrum and ferritin levels, as well as the Indice de Rigidite (IR) of the erythrocytes were recorded, before and after the first, second and third month of the study period. Finally, the rHuEpo dose/ patient was registered monthly before and during the study. During the observations, Hct (35.4 +/- 3.3 vs. 38.1 +/- 3.4, ANOVA, p < 0.03) and Hb levels (11.0 +/- 1.1 vs. 11.9 +/- 1, ANOVA, p < 0.01), were significantly increased. On the other hand, rHuEpo dose necessity/patient/week was decreased significantly (3,833 +/- 3326 vs. 1,292 +/- 1,712, ANOVA, p < 0.01), in order to succeed the target Hct level. Furthermore, red blood cells IR also appeared to have a significant decrease (16.6 +/- 7.4 vs. 13.0 +/- 3.9, paired t-test, p < 0.03). Finally, the ferrum and ferritin levels were stable during the study period. It was concluded, that in patients on, CAPD the per os L-carnitine supplementation decreased, the red blood cells IR which contributes to the: (a) Increase of Hct and Hb levels and (b) decrease of the patients rHuEpo dose/week.     

Regular low-dose intravenous iron therapy improves response to erythropoietin in haemodialysis patients

BACKGROUND.: Erythropoietin (Epo) is an effective but expensive treatmentfor anaemia in patients with chronic renal failure. Hyporesponsivenessto Epo, particularly in haemodialysis patients, is most commonlydue to a functional iron deficiency, which is difficult to monitorreliably. METHODS.: Forty-six stable haemodialysis patients, receiving Epo therapy,were commenced on regular low-dose intravenous iron (sodiumferric gluconate complex) at a dose of 62.5 mg/5 ml given asa slow injection post-dialysis twice weekly, weekly, or fort-nightly,according to their serum ferritin levels. Haemoglobin, serumferritin, Epo dose, and iron dose were measured at 6-weeklyintervals over a 6-month period. RESULTS: At the beginning of the study, 12 patients in the group hadferritin levels of less than 100 µg/l, and were thus consideredto potentially have an absolute iron deficiency. The study groupwas therefore split into two subgroups for the purpose of analysis,i.e. the 12 patients with ferritin levels of less than 100 µg/lat the start of the study or ‘low ferritin group’,and the remaining 34 patients with ferritin levels of greaterthan 100 µg/l at the start of the study or ‘normalferritin group’. In the low ferritin group (n=12), intravenous iron therapy increasedserum ferritin levels, and produced a significant rise in haemoglobin,and a significant reduction in Epo dose. (Ferritin pre-iron,median (range) 68 (20–96)µg/l; post-iron, 210.5(91–447)µg/l, P<0.003, Wilcoxon. Haemoglobinpre-iron, 10.05 (8.2–11.9)g/dl; post-iron, 11.0 (9.9–11.9)g/dl,P<0.03. Epo dose pre-iron, 9000 (4000–30000) i.u./week;post-iron, 6000 (2000–10000)i.u./week, P<0.05.) Similar results were obtained in the normal ferritin group (n=34)following intravenous iron therapy, with significant increasesin serum ferntin levels and haemoglobin concentrations, anda significant reduction in Epo dose. (Ferritin pre-iron, 176(103–519) µg/l; post-iron, 304.5 (121–792)µg/l,P<0.0001. Haemoglobin pre-iron, 9.85 (6.5–12.8)g/dl;post-iron: 11.25 (9.9–13.3)g/dl, P<0.0001. Epo dosepre-iron, 6000 (2000–15 000)i.u./week; post-iron, 4000(0–15000)i.u./week, P<0.005.) CONCLUSION.: Regular intravenous iron supplementation in haemodialysis patientsimproves the response to Epo therapy.     

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

In our earlier paper [1] 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 ptshad significantly higher mean endogenous erythropoietin (eEpo) level andlower iron reserves (IR) than HD pts who need rHuEpo therapy. The aim ofthis study was to judge whether the possibility to control anemia in ptsnot requiring rHuEpo therapy changes during a 30-month HD treatment.Serum eEpo and ferritin were measured every 6 months. After 30 months ofHD treatment 18 pts remained in this group – 5 pts died, Iunderwent transplantation. During the study period 4/18 ptspermanently 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 themean for healthy control). Pts who had the highest level of eEpo had thelowest IR. After 30 months IR were significantly lower than at thebeginning of observation (292 ± 87 vs 143 ± 127 mg).Important negative correlation between eEpo and IR was observedthroughout 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. Thestudy shows that the possibility to control anemia in pts not treatedwith rHuEpo did not change significantly during 30 months of HDtreatment. Endogenous Epo level in HD pts not treated with rHuEpo variedbetween different pts: it was permanently low in some pts, permanentlyhigh in others and stayed normal in remaining pts.     

Does long-term treatment of renal anaemia with recombinant erythropoietin influence oxidative stress in haemodialysed patients?

Background. Patients with end-stage renal failure undergoing haemodialysis (HD) are exposed to oxidative stress. Increased levels of malondialdehyde (MDA) were demonstrated in plasma of uraemic patients, indicating accelerated lipid peroxidation (LPO) as a consequence of multiple pathogenetic factors. The aim of our investigation was to examine the role of renal anaemia in oxidative stress in HD patients. Methods. MDA and 4-hydroxynonenal (HNE) were measured in three groups of patients undergoing HD: group I comprised eight patients with a blood haemoglobin (Hb) <10 g/dl (mean Hb=8.1±1.3 g/dl), and group II were eight patients with a Hb <10 g/dl (mean Hb=12.4±1.9 g/dl); none of these 16 patients had been treated with human recombinant erythropoietin (rHuEpo). Group III comprised 27 patients with a mean Hb of 10.5±1.6 g/dl after long-term rHuEpo treatment. Results. Mean plasma concentrations of both MDA and HNE were significantly higher (P<0.0001) in all 43 HD patients than in 20 healthy controls (MDA 2.85±0.25 vs 0.37± &mgr;M, HNE 0.32± vs 0.10±0.01 &mgr;M). Comprising the three groups, it was shown that HD patients with a Hb <10 g/dl had significantly higher plasma levels of LPO products (MDA 3.81±0.86 &mgr;M, HNE 0.45±0.07 &mgr;M) than HD patients with a Hb > 10 g/dl (MDA 2.77±0.58 &mgr;M, HNE 0.25±0.05 &mgr;M), and than HD patients treated with rHuEpo (MDA 2.50±0.12 &mgr;M, HNE 0.29±0.03 &mgr;M). Furthermore, an inverse correlation between plasma concentration of LPO products and haemoglobin levels was seen (r=0.62, P<0.0001). Conclusion. Radical generation in HD patients might be caused in part by renal anemia itself. Treatment with rHuEpo may decrease radical generation effectively in HD patients due to the increase in the number of red blood cells and blood haemoglobin concentration. Keywords: erythropoietin; haemodialysis; HNE; lipid peroxidation; MDA; renal anaemia      

Intervention thresholds and ceilings can determine the haemoglobin outcome distribution in a haemodialysis population.

We have explored the consequences of setting different thresholds and ceilings for erythropoietin dose changes in two randomized controlled studies of renal anaemia management based on an established algorithm. STUDY 1: A large (n=236) unselected haemodialysis cohort was randomized to monthly intervention (increased erythropoietin (Epo)) at haemoglobin (Hb) levels falling below either 10.5 g/dl (group A) or 11.5 g/dl (group B) and followed for 6 months. The mean Hb was 0.6 g/dl higher in the 11.5 g/dl threshold group (11.1 g/dl vs 11.7 g/dl) at 6 months (P=0.001++). The Epo dose did not differ between them (median 133 IU/kg/week, Interquartile range (IQR) 86-217 and 140, IQR 74-227 respectively) (P=NS(**)). STUDY 2: A large (n=211) unselected haemodialysis cohort was randomized to a reduction in Epo dose at Hb levels above either 12.0 g/dl (group C) or 13.0 g/dl (group D). The Hb outcome at 8 months differed between group C (mean 11.5 g/dl, SD 1.4) and group D (12.2, SD 2.1) (P=0.03++). The Epo dose did not significantly differ between groups C and D (median 60 IU/kg/week, IQR 32-142 and 71, IQR 38-117 respectively) (P=NS(**)). Study 1 showed that an intervention threshold of 11.0 g/dl with a mean Hb outcome of 11.6 g/dl and SD 1.6 g/dl would produce the desired UK Renal Association Standards outcome of 85% Hb > or =10.0 g/dl. Study 2 demonstrated that a ceiling of 12.0 g/dl narrowed the range of Hb values (P:<0.001##), achieving a SD of 1.37 g/dl, and reduced the number of patients with a Hb >13.0 g/dl from 25 to 12%. This narrowing of the distribution has cost implications for reaching minimum standards in a haemodialysis population. Formal use of threshold and ceiling values for intervention within an anaemia management system enabled the haemodialysis population outcome mean and SD to be literally prescribed.     

The required dose of erythropoietin during renal anaemia treatment is related to the degree of impairment in erythrocyte deformability

Background: Renal anaemia is rapidly corrected by recombinant human erythropoietin (rHuEpo) therapy, but the dose required varies greatly. Since impaired erythrocyte deformability may be one factor contributing to the development of renal anaemia, the interrelationship between that variable and the rHuEpo requirement was examined. Methods: Twenty-five patients treated with hemodialysis and rHuEpo for at least 6 months were included in the study. The Hb value had been stable and the rHuEpo dose unchanged the last two months. Using a rotational viscometer, the fluidity of erythrocytes, separated from plasma and re-suspended in isotonic buffered saline to a standardized haematocrit, was taken as a measure of erythrocyte deformability. Results: The average weekly dose of s.c. epoetin alpha was 186±93 U/kg body weight (range 56-370). The dose was correlated to the reticulocyte fraction (R-0.69, P=0.0001). When the rHuEpo dose was used as dependent variable and blood haemoglobin concentration, serum (S) albumin, S ferritin, S aluminium, S PTH, S urea, Kt/V/week, erythrocyte fluidity, and plasma viscosity were used as independent variables in a stepwise multiple regression analysis, only erythrocyte fluidity remained significantly negatively correlated to the rHuEpo dose (R=0.5, P=0.01). Despite a tendency towards higher doses of rHuEpo in patients with a C-reactive protein concentration exceeding 20 mg/l, the Hb was lower in these patients. Conclusions: We conclude that the interindividual differences in bone marrow response to rHuEpo were small in these patients. Impaired erythrocyte deformability and inflammation seem to be factors associated with increased rHuEpo requirement.     

Importance of iron supply for erythropoietin therapy

BACKGROUND.: rHuEpo and iron therapy corrects renal anaemia. However, dosage,route of administration, and monitoring of iron and rHuEpo therapyin uraemic patients remains controversial. METHODS.: Therefore a 22-month i.v. iron substitution trial, subdividedinto four study periods, was initiated in 64 iron-depleted chronichaemodialysis (HD) patients receiving i.v. rHuEpo therapy. Withinthe first period (6 months) patients were treated with high-doseiron (100mg at the end of HD treatment, mean cumulative i.v.iron saccharate dosage was 2538±810 mg per patient) inorder to replete the iron stores. During the 2nd period (6 months)the available iron pool was maintained with low-dose iron byadministration of 10, 20, or 40 mg iron at each HD, dependingon haemoglobin, serum ferritin and transferrin saturation levels.During the 3rd period (4 months), the iron-replete patientswere randomized to i.v. or s.c. route of rHuEpo administration.During the 4th period (3 months) iron substitution was omittedto exclude severe iron overload. RESULTS.: In the first study period, high-dose iron therapy dramaticallyreduced the weekly rHuEpo requirement by 70% of the initialdose (from 217±179 to 62.6±70.2 U/kg/week). Inthe 2nd period iron storage pools were easily maintained. Serumferritin and transferrin saturation levels remained stable duringthis study period. Randomization for thrice-weekly i.v. or s.c.administration of rHuEpo in the 3rd study period revealed comparableefficacy for both administration routes in iron-replete patients.In well-nourished patients (serum albumin >40 g/1) withouthyperparathyroidism (parathyroid hormone levels < 100 pg/ml),50–60 U/kg/week rHuEpo were required in contrast to >100 U/kg/week in patients with hyperparathyroidism. In the 4thstudy period, withdrawal of iron administration led to a rapiddecrease of serum ferritin and transferrin saturation levels,indicating the absence of severe iron overload. CONCLUSIONS.: Long-term thrice-weekly i.v. low-dose iron therapy (10–20mg per HD treatment) proved to be a very effective, economicaland safe treatment schedule for iron-replete HD patients. Intravenousand s.c. rHuEpo therapy was equally efficacious in iron-replete,well-nourished patients. HD patients with increased parathyroidhormone levels require significantly more rHuEpo than HD patientswith parathyroid hormone levels values <100 pg/ml).     

The role of aluminium and parathyroid hormone in erythropoietin resistance in haemodialysis patients

Recombinant human erythropoietin (rHuEpo) is an effective therapy for anaemia in most patients with end-stage renal disease (ESRD). However, there remain a minority of patients with ESRD who are resistant to the effects of rHuEpo. The present study examined the role of aluminium overload and hyperparathyroidism of the biological effects of rHuEpo. Twenty-two patients aged 26-74 (mean 53 +/- SD 15.5) received rHuEpo 50-200 U/kg per week for 16.5 +/- 8.0 months (range 3-27). Haemoglobin was maintained at 11.5-13.0 g/dl by appropriate dose adjustment. Iron supplements were provided to maintain serum ferritin greater than 200 ng/ml. The mean time to rHuEpo response (Hb greater than 2 g/dl over baseline) was 6.1 +/- 2.6 weeks. Mean pretreatment serum aluminium correlated with time to Hb response (r = 0.48; P less than 0.05) and pretreatment mean corpuscular volume (r = 0.43; P less than 0.05) but not with eventual rHuEpo maintenance dose. PTH did not correlate with either Hb response or eventual maintenance rHuEpo dose. In summary, elevated serum aluminium concentrations were associated with an initial resistance to the biological effects of rHuEpo but had no effect on long-term dose requirements. In contrast, no impact of PTH on either immediate or long-term rHuEpo dose was evident.     

Inverse relationships between haemoglobin and ristocetin-induced platelet aggregation in haemodialysis patients under erythropoietin therapy

BACKGROUND.: Amelioration of the anaemia of chronic renal failure and subsequentimproved haemorheology result in correction of bleeding diathesisas evidenced by shortening of the skin bleeding time (BT). However,the relationship between the haematocrit and platelet-vesselwall interactions in haemodialysis (HD) patients under recombinanthuman erythropoietin (rHuEpo) therapy, assessed by plateletaggregation in response to ristocetin is more complex and somewhatinconsistent. METHODS.: We investigated the relationship between haemoglobin (Hb) levelsand whole blood ristocetininduced platelet aggregation (electricimpedance method) in 28 HD patients treated with rHuEpo, andwith normal BT. The measurements were repeated in 16 subjectsafter having reduced platelet aggregability with orally administeredketanserin. RESULTS.: Ristocetin-induced platelet aggregation in the whole group wascomparable to those found in 21 age-matched healthy subjects(normals) and in 25 HD patients not treated with rHuEpo (uraemics).Interestingly, a significant inverse correlation between thisaggregation and Hb concentration was found (r = –0.392,P<0.05). In the group of 16 patients, the preketanserin aggregationwas more intensive than in the normals and uraemics (P<0.05).Ketanserin produced a fall in ristocetin-induced platelet aggregation(P<0.02), prolongation of the BT (P<0.02) and, unexpectedly,a decrease in serum Epo concentration (P<0.0002) and theHb level (P<0.001). Again, an inverse correlation betweendepressed ristocetin-induced platelet aggregation and loweredHb concentration was found (r= –0.590, P<0.02). Moreover,a strong positive correlation between the extent of preketanserinplatelet aggregation and the decrease in the intensity of thisprocess that followed the trial was observed (r=0.919, P<0.000005).There were no changes in other haematological parameters orarterial blood pressure. CONCLUSIONS.: Considering the role of von Willebrand factor and fibrinogenin mediating ristocetin-induced platelet aggregation, and enhancedsynthesis and/or release of these macromolecules in responseto uraemia or inflammation, we suggest that exaggerated whole-bloodplatelet aggregability to ristocetin points to blunted erythropoiesisin HD patients on rHuEpo therapy.     

Renal clearance of endogenous erythropoietin in patients with proteinuria

Recent data indicated the importance of urinary losses of erythropoietin (Epo) in the pathogenesis of anaemia in patients with nephrotic syndrome. In the present study we aimed to investigate plasma and urinary Epo levels and their renal handling in relation to β₂-microglobulin (β₂m), sodium metabolism and the renin-angiotensin-aldosterone system (RAAS), respectively, in patients with sub-nephrotic range proteinuria (SNP), microalbuminuric diabetics and hypertensives, and in healthy subjects studied on a standardized diet containing 120 mmol sodium and 70 g protein per day. We found that patients with SNP were characterized by lower plasma levels of Epo than healthy subjects but no differences were found in urinary excretion of Epo, endogenous Epo clearance and its fractional excretion (FE_Epo). There were no differences between groups in FEβ_2m and FE_Na and plasma aldoterone levels but plasma renin activity was higher in patients with SNP than in the controls. No relationships were found between Epo levels and activity of the RAAS and sodium metabolism, respectively. Our data suggest that lower levels of plasma Epo in patients with SNP and normal renal excretory function are not due to urinary losses of Epo but rather to the decreased production/degradation ratio.     

Long-term effects on quality of life in haemodialysis patients of correction of anaemia with erythropoietin

Quality of life assessments were performed in 24 haemodialysispatients (10 males, 14 females, age 45 ±15 years) undergoingrHuEpo treatment. The results in the rHuEpo-treated patientswere compared with those in eight haemodialysis patients noton rHuEpo and with the results of a nationwide study of dialysispatients in Sweden (carried out before rHuEpo was registered).Survey questionnaires (112 items, divided into three dimensions,i.e. physical, social, and emotional wellbeing) were completedbefore treatment (Hb 73± 1.1 g/1), when the target Hbvalue of 10 g/dl was reached (1–7 months) and in 14 patients1 year after correction of the anaemia. Before treatment, therHuEpo group had significantly more complaints about poor appetite,fatigue, and irritability than the controls. After the anaemiawas corrected, the rHuEpo group had significantly improved physicaland emotional wellbeing. The most significant changes occurredin satisfaction with health, physical activities of daily life,and fatigue. Alterations in emotional symptoms, such as depressionand apathy, were less pronounced. Only minor changes were observedin their social wellbeing. One year after correction of theanaemia, the improvements in physical and emotional wellbeingwere still present in the rHuEpo-treated patients. A positiveeffect was also noted on hospitalization rate. Scores for thesubdimensions of satisfaction with health, sexual adjustment,physical symptoms, and emotional wellbeing improved in the rHuEpo-treatedgroup and reached a level that was the same, or even higher,than the scores in the dialysis patients in the nationwide study.In conclusion, the quality of life improved during rHuEpo treatment.The greatest changes were seen in satisfaction with health,physical activity, and emotional wellbeing. The positive effectsobserved after the correction of anaemia persisted after morethan a year on rHuEpo treatment.