Haemodynamic effect of recombinant human erythropoietin on hypotensive haemodialysis patients

The haemodynamic effects of recombinant human erythropoietin (rHuEpo) on anaemic haemodialysis patients suffering from chronic hypotension were examined. rHuEpo increased the haematocrit to around 30% and increased diastolic blood pressure by 12.4%, statistically significant. Correspondingly, the total peripheral resistance index increased 42.3% while the cardiac index decreased 24.4% (P less than 0.05) respectively. Blood volume, plasma renin activity and plasma noradrenaline did not change significantly. The extent of blood pressure elevation and haemodynamic alteration did not differ from our previous report on anaemic haemodialysis patients without hypotension. The incidence of hypotensive episodes and fluid supplementation did not change significantly after rHuEpo treatment. In conclusion, by using rHuEpo, approximately a 10% increase of blood pressure can be expected. However no substantial improvement in hypotensive episodes can be expected in chronic haemodialysis patients suffering from hypotension.     

Lipid profile in haemodialysis patients treated with recombinant human erythropoietin

Background: The long-term effect of recombinant human erythropoietin (rhEPO) on the blood-lipid profile has not been well documented. The aim of this study was to evaluate whether rhEPO therapy affects the lipid pattern. Methods: A group of 102 maintenance haemodialysis patients were treated for 2 years with rhEPO given intravenously at the end of the dialysis session. Attempts were made to keep the haemoglobin (Hb) at 10-11 g/dl and/or the haematocrit (Hct) at 30-35%. Twenty maintenance haemodialysis patients not treated with rhEPO were examined as controls. Total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, apolipoproteins A1 and B, and lipoprotein (a) [Lp (a)] were assessed at baseline (without rhEPO), and 1 and 2 years after the beginning of treatment. Hb, Hct and ferritin were measured monthly, and Kt/v was evaluated monthly and kept above 1.1. Results: During follow-up, in both groups, there was a significant increase in Apo A1 and no significant changes in the other lipid parameters. In the treated group, Hb and Hct increased significantly after the fourth month of treatment. Conclusions: Erythropoietin therapy does not affect significantly the levels of total cholesterol, LDL- and HDL-cholesterol, triglycerides, Apo B and Lp (a) in maintenance hemodialysis patients.     

Plasma endothelin in haemodialysis patients treated with recombinant human erythropoietin

Predialysis plasma endothelin (ET) values were followed duringthe first 8 weeks of rHuEpo treatment in 12 patients on routinehaemodialysis. Mean plasma ET was significantly increased inuraemic patients before rHuEpo (27.911.4 pmol/1), as comparedto 40 healthy controls (16.55.7 pmol/1) (p<0.0001). UnderrHuEpo treatment, predialysis values remained unchanged althoughdiastolic blood pressure increased after 2 and 6 weeks. We foundno correlation between ET and haemoglobin or blood pressurebefore or under rHuEpo treatment. These results confirmed thehigh levels of plasma ET in haemodialysis patients, but no increasewas observed during rHuEpo treatment.     

Aluminium interference in the treatment of haemodialysis patients with recombinant human erythropoietin

In nine chronic haemodialysis patients a desferrioxamine (DFO) load test (40 mg/kg body-weight) was performed 1 year after the beginning of treatment with recombinant human erythropoietin (rHuEpo). The patients were then divided into two groups. Group A comprised five patients with a greater mean aluminium (204 +/- 28 micrograms/l) than the four patients in group B. Group A was given a mean dose of 25.8 g (range 14-39 g) of DFO over 6 months. Group B (aluminium values 112 +/- 36 micrograms/l) was never treated with DFO. During the period of observation, plasma iron, serum ferritin and transferrin, as well as iron supplementation, did not differ between the groups. After DFO treatment a second DFO load test was performed. The mean predialysis aluminium value was significantly reduced in group A (204 +/- 28 vs 111 +/- 72 micrograms/l; P less than 0.05), while remaining unchanged in group B (112 +/- 36 vs 140 +/- 39 micrograms/l; P = ns). In both groups, the doses of rHuEpo necessary to maintain the same haemoglobin values decreased with time, but reduced significantly only in group A (298 +/- 105 vs 110 +/- 61 mu/kg per week; delta -63%; P less than 0.01). Thus, aluminium interferes with the response to rHuEpo in haemodialysis patients, and the correction of aluminium overload with DFO can allow a considerable sparing of rHuEpo.     

Intravenous versus subcutaneous administration of recombinant human erythropoietin in patients on haemodialysis and CAPD.

The most effective route of administration of rHuEpo is still a matter of discussion. Prospectively we studied subcutaneous (s.c.) versus intravenous (i.v.) administration in three comparable groups of patients; HD-s.c. (n = 9), HD-i.v. (n = 11), and CAPD-s.c. (n = 9). All the groups initially received 50 units/kg three times weekly. During the first 8 weeks dose adjustments were made only if target haemoglobin exceeded 11.3 g/dl (7 mM). Target haemoglobin was reached after 84 (42-98) days in the i.v. group and 42 (14-77) and 42 (28-56) respectively in the HD-s.c. and CAPD groups. The difference was statistically significant (P less than 0.05). Even the cumulative doses to reach target haemoglobin were significantly less in the two s.c. groups. To maintain haemoglobin at about 11.3 g/dl, weekly doses were as follows: HD-i.v. 125 U/kg (86-168), HD-s.c. 63 U/kg (20-85), and CAPD 72 U/kg (31-100). The total observation time after the target haemoglobin level was reached, was median 130 (114-264) days. The difference between the i.v. group and the two s.c. groups was statistically significant, (P less than 0.05) whereas there was no difference between the s.c. groups. We conclude that s.c. administration of rHuEpo is more effective in induction as well as in maintenance therapy and that s.c. administration is equally efficient in HD and CAPD patients.     

Dialysate related cytokine induction and response to recombinant human erythropoietin in haemodialysis patients.

BACKGROUND: Chronic inflammatory disorders or infections represent a major cause of hyporesponsiveness to recombinant human erythropoietin (rHuEpo). To test the hypothesis that dialysate-related cytokine induction alters the response to rHuEpo, we conducted a prospective study with matched pairs of chronic haemodialysis patients. We compared the effect of two dialysis fluids, differing in their microbiological quality, on the rHuEpo therapy. METHODS: Thirty male patients with end-stage renal disease maintained on regular haemodialysis were assigned either to a group treated with conventional (potentially microbiologically contaminated) dialysate (group I) or to a group treated with online-produced ultrapure dialysate (group II). Randomization was stratified according to the maintenance dose of rHuEpo necessary to maintain a target haemoglobin level of 10-10.5 g/dl. Patients were followed for 12 months. Kt/V was calculated by the formula of Daugirdas. Haemoglobin levels were measured weekly and serum ferritin concentrations were determined at 6-week intervals. C-reactive protein (CRP) and interleukin-6 (IL-6) was measured by an ELISA at the start of the study and after 3, 6 and 12 months. RESULTS: In group I, continuous use of bicarbonate dialysate did not change the rHuEpo dosage given to achieve the target haemoglobin level and was associated with elevated surrogate markers (CRP, IL-6) of cytokine-induced inflammation. The switch from conventional to online-produced ultrapure dialysate in group II resulted in a lower bacterial contamination with a significant decrease of CRP and IL-6 blood levels. It was accompanied by a significant and sustained reduction of the rHuEpo dosage, which was required to correct the anaemia. Using multiple regression analysis, IL-6 levels are shown to have a strong predictive value for rHuEpo dosage in both groups. CONCLUSIONS: Our data demonstrate that dialysate-related factors such as low bacterial contamination can induce the activation of monocytes, resulting in elevated serum levels of IL-6. Dialysate-related cytokine induction might diminish erythropoiesis. The use of pyrogen free ultrapure dialysate resulted in a better response to rHuEpo. Not only would it save money, but it would also help to maintain an optimal haemoglobin level without further increase in rHuEpo dosage.     

Aluminium overload and response to recombinant human erythropoietin in patients under chronic haemodialysis.

In this work, of 51 patients treated by rHuEpo, 25 were selected for study. The selection criteria were absence of clinically evident causes of anaemia other than end-stage renal failure, such as chronic infection, active systemic disease, bleeding sites, and vitamin B12 or iron deficiencies. Serum aluminum was assessed before dialysis and the presence of aluminium overload was confirmed by a DFO test. rHuEpo was given in a dose of 50 U/kg body-weight after each dialysis session three times weekly and the response to treatment was evaluated monthly for 8 months. Our data showed significant correlation between serum aluminum and the response to rHuEpo. The response was significantly greater in those with lower serum aluminium. We conclude that the aluminium load in chronic haemodialysis patients may have an effect on the response to rHuEpo.     

Once weekly versus twice weekly subcutaneous administration of recombinant human erythropoietin in haemodialysis patients.

Optimal route and frequency of administration of recombinant human erythropoietin (rHuEPO) have not yet been determined. There is some evidence to suggest that subcutaneous administration of rHuEPO may be more effective than the intravenous route in reversing renal anemia. It is also unclear whether rHuEPO is more effective when given by a large intermittent dose or by more frequent multiple divided doses. We have compared the effect of twice weekly versus once weekly subcutaneous administration of rHuEPO in two groups of haemodialysis patients. At the end of 12 weeks of treatment with rHuEPO, the mean haemoglobin levels had risen from 6.9 +/- (SD) 0.7 to 8.9 +/- 1.3 g/dl in the once weekly group and from 7.2 +/- 1.0 to 9.3 +/- 1.6 g/dl in the twice weekly group. The average doses of rHuEPO used during the study were 127 +/- 6 and 115 +/- 18 U/kg body weight/week for the once weekly and twice weekly groups, respectively. Subcutaneous administration of low-dose rHuEPO is effective in reversing renal anaemia. Similar responses were obtained with once weekly and twice weekly regimens.     

Effect of recombinant human erythropoietin therapy on ambulatory blood pressure and heart rate in chronic haemodialysis patients.

Systemic hypertension as assessed by causal blood pressure measurements is a frequently reported side-effect of recombinant human erythropoietin (rHuEpo) treatment. We investigated the effect of rHuEpo treatment on the 24-h ambulatory blood pressure and heart rate profiles of 13 chronic haemodialysis patients. After 3-4 months of rHuEpo therapy it was found that the mean haematocrit had increased from 24.5 +/- 1.0% to 32.0 +/- 1.1% (P less than 0.005), while body-weight and control of uraemia as assessed by routine laboratory data remained unchanged. Despite gradual and incomplete correction of anaemia by use of low doses of rHuEpo, increases in the ambulatory systolic and diastolic blood pressure were found. The greatest increases affected day-time systolic blood pressure and night-time diastolic blood pressure, and these increases were significant (P less than 0.05). As a result, pulse pressure increased during day-time (P less than 0.05) while the night-time decline in diastolic blood pressure disappeared. An increase in peripheral resistance after partial correction of renal anaemia might explain these observations. rHuEpo therapy increased the percentage of abnormal ambulatory blood pressure measurements (defined as systolic blood pressure greater than 140 mmHg and/or diastolic blood pressure greater than 90 mmHg) from 33% to 52% (P less than 0.05) while in contrast, mean casual prehaemodialytic and posthaemodialytic blood pressure values remained unchanged. We conclude that changes in 24-h blood pressure profiles should be carefully assessed by ambulatory blood pressure monitoring in haemodialysis patients treated with rHuEpo, since these changes are likely to be missed when only causal blood pressures are measured.     

The effects of recombinant human erythropoietin on hemostasis and fibrinolysis in hemodialysis patients.

Thromboembolism might complicate the treatment of patients with chronic renal failure with Recombinant Human Erythropoietin (ReHuEPO). In order to detect prothrombotic changes, a number of hemostatic and fibrinolytic parameters was determined during ReHuEPO treatment of fifteen chronic hemodialysis patients (mean age 47.1 years; ten females, five males). To avoid the influence of hemoconcentration and/or dilution, the patients were kept normovolemic, using the method of echography of the inferior vena cava diameter. In a first group of eight patients, we investigated platelet count and function. During ReHuEPO, a significant rise of hematocrit (19 +/- 3 to 34 +/- 5%, p < 0.001) was observed. Bleeding time shortened (7'33' +/- 3'39' to 3'41' +/- 3'19'; p < 0.001) and platelet count increased (222 +/- 45 to 254 +/- 49 10 9/l; p < 0.005). The initial negative in vitro spontaneous platelet reactivity became positive in two of them, whereas the decrease in ADP threshold in the whole group (2.0 +/- 0.1 to 1.10 +/- 0.4 mumol, p < 0.02) indicated an increased induced platelet reactivity. In all patients prothrombotic changes were observed. The protein-C antigen and protein-C activity and the total and free protein-S antigen decreased significantly. The plasminogen activator inhibitor (PAI) activity in the whole group did not change significantly (6.4 +/- 4.1 to 5.4 +/- 4.8 AU/ml). However, in the patients with fistula thrombosis (n = 3), higher values in all test points were found compared to those without thrombosis.     

Relationship between obstruction of arteriovenous fistula and plasma level of endothelin-1 in long-term haemodialysis patients

Summary: The relationship between the patency status of the autogenous arteriovenous (A-V) fistula and the plasma level of endothelin-1 (ET-1) was studied in 41 patients who had been receiving routine longterm haemodialysis for more than 10 years. the ET-1 level in the haemodialysis patients (mean ± s.d.=2.1 ± 0.9 pg/mL) was significantly elevated compared with that in healthy controls ( n =16; 1.1 ± 0.4 pg/mL; P < 0.01). the patients were classified into two groups according to whether the original A-V fistula had remained patent for more than 10 years or had been repaired due to frequent (more than twice) obstruction. Among all 41 patients, 21 were receiving recombinant human erythropoietin (rHuEpo) intravenously (i.v.). In the rHuEpo-treated group, the plasma ET-1 ( n =21; 2.4 ± 0.8 pg/mL) was significantly elevated than that in the rHuEpo-untreated group ( n =20; 1.9 ± 0.9 pg/mL; P<0.05). After exclusion of the 21 rHuEpo-treated patients, the ET-1 level in the repaired fistula group ( n =11; 2.3 ± 0.9 pg/mL) was significantly higher than that in the patent original fistula group ( n =9; 1.3 ± 0.7 pg/mL; P <0.02). Based on these results, we conclude that ET-1 shows a close relation to venous stenosis of the A-V fistula which may be due to its vasoconstrictive and smooth muscle cell-proliferating effects.     

Effect of recombinant human erythropoietin on synthesis of methylguanidine in uraemic patients on haemodialysis or continuous ambulatory peritoneal dialysis

The effect of recombinant human erythropoietin (rHuEPO) on synthesis of methylguanidine was studied in 6 uraemic patients on haemodialysis and 5 uraemic patients on continuous ambulatory peritoneal dialysis (CAPD). The Two groups of patients were started on a 24-week course of thrice weekly 1500 IU of rHuEPO by the intravenous route. Serum methylguanidine level and methylguanidine/creatinine ratio were comparable in these groups. In the two groups no significant differences were observed in these measurements comparing the pretreatment values with those 4, 8, 12 or 24 weeks after starting rHuEPO administration. During rHuEPO therapy, serum methylguanidine levels and methylguanidine/creatinine ratio showed no considerable difference between the two groups. These findings suggest that administration of rHuEPO does not alter methylguanidine synthesis in uraemic patients on haemodialysis and CAPD.     

Long-term therapy with recombinant human erythropoietin increases CD8+ T-cell apoptosis in haemodialysis patients.

BACKGROUND: We intended to assess the intensity of apoptosis in the CD4+ and CD8+ T-lymphocytes of haemodialysis (HD) patients on recombinant human erythropoietin (rHuEpo). METHODS: The expression of Fas, tumour necrosis factor-alpha receptors (TNFRI and TNFRII) and the CD28 molecule on lymphocytes was evaluated in 15 HD patients before and during treatment with rHuEpo. In cultures of peripheral blood mononuclear cells (PBMCs) stimulated with rHuEpo, phytohaemagglutinin and camptothecin, our measures of apoptosis were the percentages of cells with subdiploid DNA content and of annexin V-stained cells. Results, Therapy with rHuEpo did not affect CD4+ T cells but decreased the percentage of CD8+ T cells in peripheral blood. The intensity of apoptosis in both CD4+ and CD8+ T cells at baseline was lower in HD patients than in healthy volunteers, and increased in those treated with rHuEpo. In vitro, rHuEpo did not induce apoptosis in PBMCs. The percentage of CD8+Fas+ T cells was constant, while that of CD8+TNFRI+ cells declined during follow-up. There was an increase in the percentage of CD28+ T cells, mainly in the CD8+ compartment, as early as 1 month after the introduction of rHuEpo. CONCLUSIONS: Treatment with rHupo caused a decline of CD8+ T cells in HD patients, which most probably was mediated via the TNFRI-related apoptotic pathway and was independent of Fas expression. Apoptosis in vitro was not directly influenced by rHuEpo, suggesting that the process in vivo was only initiated by rHuEpo supplementation.     

Effect of iron treatment on circulating cytokine levels in ESRD patients receiving recombinant human erythropoietin

BACKGROUND: Anemia in patients with end-stage renal disease (ESRD) is treated with recombinant human erythropoietin (rhEPO) often in combination with iron. However, iron catalyzes the formation of toxic radicals, which might promote vascular damage, is a nutrient for microorganisms, and negatively affects immune pathways, thus increasing the risk for severe infections. METHODS: We investigated 28 patients on chronic hemodialysis who were randomized to receive either rhEPO alone (N = 15) or rhEPO in combination with intravenous iron (N = 13) for a period of 12 weeks. We analyzed iron therapy associated changes in cytokine patterns and endogenous radical formation. RESULTS: Tumor necrosis factor-alpha (TNF-alpha) levels were increased in ESRD patients at study entry and then decreased significantly over time in subjects receiving additional iron, while they increased with rhEPO alone. In contrast, we found serum concentrations of the anti-inflammatory cytokine interleukin (IL)-4 to increase with iron therapy. A significant negative correlation between iron availability, as determined by transferrin saturation, and TNF-alpha levels (P = 0.008) and a positive one between transferring saturation and IL-4 (P = 0.02) pointed to the potential role of iron to induce immunologic changes. Interestingly, iron therapy resulted in a slight decrease in the amounts of endogenous peroxides, which may be referred to reduced TNF-alpha concentrations since peroxide concentrations were positively correlated to TNF-alpha levels (P = 0.046) and negatively to transferrin saturation (P = 0.02). CONCLUSION: Iron supplementation in ESRD patients down-regulates proinflammatory immune effector pathways and stimulates the expression of the anti-inflammatory cytokine IL-4. Such a condition is detrimental for host response toward invading pathogens. However, tissue damage by radicals such as endogenous peroxides may be reduced in this condition due to impaired TNF-alpha formation.     

Increased plasma S-nitrosothiol levels in chronic haemodialysis patients

Nephrol Dial Transplant 2003; 18: 153–157     

Low-dose aspirin does not prevent thrombovascular accidents in low-risk haemodialysis patients during treatment with recombinant human erythropoietin

Treatment of the anaemia of renal disease with recombinant humanerythropoietin results in an improvement of haemostasis andan increased risk of thrombovascular accidents. In this prospective,placebo-controlled, double-blind, and cross-over study, theeffects of low-dose acetylsalicylic acid (30 mg daily) on thromboticand bleeding events during the initial period of treatment witherythropoietin in anaemic haemodialysis patients without previousthrombovascular accidents or known increased risk for thrombosiswere investigated. During correction of the haematocrit andthe first 3 months thereafter, group A (n = 68) received placeboand group B (n = 69) 30 mg acetylsalicylic acid daily. Cross-overtook place after the 3rd month of a stable haematocrit. Thestudy ended 3 months later. Target haematocrit (30–35%) was reached in 12.4±8 weeks (M ± SD). In group A the bleeding time was 382±285s, decreasing to 282±208 before cross-over (P<0.0l),and increasing to 395±271 (P<0.05) there after. Ingroup B the bleeding time was 390±381 s, 406±267(NS), and 285±238 (P<0.05) respectively. Twenty-twothrombovascular accidents were seen (16%, 13 during acetylsalicylicacid and 9 during placebo, NS), including 17 fistula thromboses.The incidence of bleeding events was not significantly differentbetween regimens. In conclusion, erythropoietin treatment resulted in a reductionof the bleeding time. When 30 mg acetylsalicylic acid was takenduring the treatment, the bleeding time did not decrease. Theregimen did not result in an increased number of bleeding events,but neither were thrombovascular accidents prevented in low-riskpatients.     

Vitamin C plasma level and response to erythropoietin in patients on maintenance haemodialysis.

BACKGROUND: Intravenous vitamin C supplementation to haemodialysis patients might ameliorate responsiveness to recombinant human erythropoietin (rHuEpo). This study was performed to analyse the relation between vitamin C plasma concentration and response to rHuEpo. METHODS: In a cross-sectional, single-centre observational study including all haemodialysis patients, pre-dialysis plasma vitamin C concentrations were measured by high-performance liquid chromatography and response to rHuEpo (haemoglobin concentration/international units rHuEpo/kg/week) was recorded together with baseline laboratory data. RESULTS: Univariate analysis yielded a significant correlation between vitamin C plasma levels and response to rHuEpo (n = 130, r = 0.25, P = 0.004), which still persisted after adjustment for transferrin saturation, C-reactive protein, malondialdehyde, parathyroid hormone, route of rHuEpo administration, residual renal function and diabetes mellitus (adjusted r = 0.23, P = 0.014). Analysis per quartiles of vitamin C plasma level revealed a significantly lower response to rHuEpo with decreasing vitamin C values (P = 0.026). CONCLUSIONS: In unselected haemodialysis patients, vitamin C plasma levels account, at least partially, for the response to rHuEpo. Larger-sized interventional studies are needed to find out whether vitamin C plasma levels may or may not appropriately reflect the potential beneficial effect of vitamin C supplements on rHuEpo responsiveness.