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.     

Protocolized anemia management with erythropoietin in hemodialysis patients: a randomized controlled trial

Treatment of the anemia of chronic renal failure with exogenous recombinant human erythropoietin (rHuEpo) is well established. The objective of this randomized clinical trial was to evaluate an anemia management team protocol in hemodialysis patients, using subcutaneous rHuEpo and intravenous iron. A total of 215 patients were randomized to either usual care or the protocol. The primary outcome was the proportion of patient hemoglobin (Hgb) values between 11.0 and 12.5 g/dl over the final 8 wk. The study was halted after 240 d because of an institutional change to intravenous rHuEpo. The proportion of Hgb values in the target range increased from 47.4% to 62.8% overall (P = 0.001); there was no difference between treatment groups. The proportion of baseline Hgb values between 11.0 and 12.5 g/dl increased from 44.6% in patients who had enrolled within the first 3 mo of study inception to 75.0% in those who started later (P = 0.017), suggesting a Hawthorne effect. A nonsignificant decrease in rHuEpo dose was observed in the protocol group; subgroup analysis in patients who were enrolled for at least 5 mo demonstrated a reduction in the rHuEpo dose of 2788 units/wk in the protocol group (P < 0.05), independent of intravenous iron dose. Multivariate analysis demonstrated that a higher transferrin saturation and albumin and protocol group assignment were associated with a lower final rHuEpo dose. This study demonstrated that a protocolized approach to anemia management in hemodialysis patients results in comparable Hgb levels and may reduce rHuEpo requirements, independent of iron use.     

Recombinant human erythropoietin: implications for nephrology

The pathophysiology of the anemia of chronic renal failure (CRF), erythropoietin physiology, the characteristics of recombinant human erythropoietin, and the results of nearly 2 years of therapy with this product in hemodialysis patients are detailed in this review. This anemia is primarily an endocrine deficiency state corrected by the hormone erythropoietin. Correction of the anemia eliminates transfusions and their associated risks, improves physical endurance, and results in healthier patients beginning dialysis. Adequate support services will be necessary to maximize patient rehabilitation and employment potential. Further research is needed to better understand erythropoietin physiology and metabolism, and the impact of uremia on end organ function in the absence of anemia.     

Monitoring the content of reticulocyte hemoglobin (CHr) as the progression of anemia in nondialysis chronic renal failure (CRF) patients

BACKGROUND: We previously showed that the content of reticulocyte hemoglobin (CHr) is a reliable measure of iron status in chronic dialysis patients with erythrocytopoiesis. The CHr was significantly correlated with conventional parameters of iron deficiency in dialysis patients. We attempted to utilize the measurement of CHr levels to monitor iron status and clarify the changes in iron levels that occur as renal anemia progresses in patients with chronic renal failure (CRF). METHODS: We measured CHr, iron parameters, and the intrinsic erythropoietin (EPO) concentration in nondialysis CRF patients who visited our outpatient clinic (n=211). Iron deficiency was defined according to the transferrin saturation (TSAT) and ferritin levels. Conventional red blood cell parameters and CHr levels were measured using an ADVIA120 autoanalyzer (Bayer Medical, USA). RESULTS: The mean CHr value of the nondialysis CRF patients (creatinine clearance less than 70 mL/min) was 32.3 pg, which was not significantly different from that of the dialysis patients. Significant correlations were found between CHr and ferritin levels (r=0.042, p<0.0403) and CHr and TSAT levels (r=0.040, p<0.0157). A positive correlation was observed between the CHr and serum creatinine levels. Nondialysis CRF patients treated with recombinant human EPO (rHuEPO) at a dose of 24,000 U/month exhibited lower CHr levels, compared with those of other patients who received less than 24,000 U/month. CONCLUSION: CHr is an easily measurable and trustworthy marker of iron status in nondialysis CRF patients. Moreover, the CHr level was also sensitive to iron alterations in nondialysis CRF patients receiving rHuEPO treatment, and thus, the CHr value could likely provide useful information regarding the need for iron supplementation.     

Recombinant human erythropoietin: 18 months' experience in hemodialysis patients

It has been shown that the regular administration of erythropoietin (EPO) permits the correction of anemia in end-stage renal failure patients. We analyzed the effect of chronic administration of EPO in 13 stable, regularly dialyzed end-stage renal failure patients over an 18-month period. The effects of EPO were evaluated according to standard criteria including clinical status, blood pressure control, hematology and biochemistry data, protein nutritional status, and dialysis efficiency. Following a 2-week control period, EPO was administered intravenously (IV) after the dialysis session according to a two-phase protocol. The first period (correction phase) consisted of a stepwise EPO dose increment, starting at 3 x 24 IU/kg/wk and doubling the dose every 14 days according to hemoglobin response in order to achieve a target hemoglobin level of approximately 11.0 g/dL (110 g/L). In the second period (maintenance phase) EPO dose was optimized to maintain the hemoglobin level between 100 and 110 g/L (10.0 and 11.0 g/dL), by adjusting either the unit dose or the frequency of injection. Anemia was corrected in all patients within 11 weeks, with EPO dose increasing from 72 to 360 IU/kg/wk. The stabilization of hemoglobin was achieved with an average EPO dose of 275 IU/kg/wk (50 to 476 IU/kg/wk). Concomitantly, a subjective and clinical improvement was noted in all patients. The dialysis efficacy remained in an acceptable range throughout the study, falling significantly (approximately 10%) through the first 3 months of treatment to stabilize at an effective urea clearance of approximately 120 L/wk. The dietary protein intake calculated from urea kinetic modeling ranged between 1.1 and 1.2 g/kg/d.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of i.v. iron alone or in combination with low-dose erythropoietin in the rapid correction of anemia of chronic renal failure in the predialysis period

BACKGROUND: It is now more and more evident that anemia of predialysis chronic renal failure (CRF) should be actively treated, since long-standing anemia may cause irremediable damage to the heart. The most common form of treatment of this anemia is subcutaneous erythropoietin (EPO). iron (Fe) deficiency can also contribute to anemia in predialysis CRF, and intravenous iron (i.v. Fe) can frequently improve it. It is possible, therefore, that the combination of EPO and i.v. Fe may have an additive effect, and cause a rapid improvement in anemia with relatively small doses of EPO. PURPOSE: The purpose of this study was an initial study: to assess the ability of a combination of low-dose EPO and i.v. Fe, given weekly for 5 doses, to correct the anemia of predialysis CRF patients compared to the use of i.v. Fe alone in a randomized study. In the follow-up study: to assess the ability of the maintenance of adequate iron stores for one year to achieve and maintain the target Hct of 35% with the minimum dose of EPO. Initial study: METHOD: Ninety predialysis CRF patients (creatinine clearance 10-40 ml/min/1.73 m2 received either: Group A (45 patients): 200 mg i.v. Fe as Fe sucrose (Venofer, Vifor Int.) once per week for 5 doses in combination with 2,000 international units (IU) EPO (Eprex, Cilag-Janssen), subcutaneously given simultaneously also for 5 doses. Group B (45 patients): the same dose of i.v. Fe as in Group A but without EPO. RESULTS: The mean increase in hematocrit (Hct) and hemoglobin (Hb) by one week after the last dose was greater in group A, 4.54 +/- 2.64% (p < 0.01) and 1.37 +/- 0.84 g% (p < 0.01), respectively, than in Group B, 2.74 +/- 2.72% (p < 0.05) and 0.91 +/- 0.78 g% (p < 0.05), respectively. 80% of those in Group A had an increase in Hct of 3 vol% or more compared to 48.9% in Group B (p < 0.01). 40% of those in Group A reached the target Hct of 35% compared to 28.9% in Group B (p > 0.05). Follow-up study: During a 12-month follow-up period, enough i.v. iron was given to maintain the Hct at 35%, while keeping the serum ferritin at < 400 ug/l and % Fe Sat at < 40%. If the i.v. Fe alone was not capable of maintaining the target Hct, EPO was given in increasing doses. Eighteen patients required dialysis. Of the 72 patients who did not require dialysis, 24 (33.3%) maintained the target Hct with i.v. Fe alone, without EPO. All the remaining 48 patients (66.7%) continued to receive EPO in addition to the i.v. Fe, and 47 achieved and maintained the target Hct with a mean EPO dose of 2,979 +/- 1,326 IU/week. CONCLUSION: The combination of low-dose EPO and i.v. Fe had a rapid and additive effect on the correction of anemia in CRF predialysis patients. Maintaining adequate iron stores with i.v. Fe during a subsequent maintenance phase allowed the target Hct of 35% to be reached and maintained with low-dose EPO in two-thirds of the predialysis patients and with no EPO at all in one-third.     

High dose enalapril impairs the response to erythropoietin treatment in haemodialysis patients

Background: The resistence to recombinant human erythropoietin (rHuEpo) therapy in haemodialysis (HD) patients has multifactorial aetiologies; erythropoietin insufficiency, dialysis insufficiency, iron deficiency, and secondary hyperparathyroidism. Angiotensin-converting enzyme (ACE) inhibitors induce anaemia in patients with essential hypertension, congestive heart failure, chronic renal insufficiency, and renal transplants. Data exist suggesting that ACE inhibitors impair erythropoiesis in HD patients. Therefore the aim of this study was to investigate the impact of enalapril on rHuEpo requirement. Methods: In the present prospective non-randomized study of 12 months, we compared the effects of enalapril and nifedipine on rHuEpo requirement in 40 hypertensive patients receiving rHuEpo for more than 6 months on maintenance haemodialysis. Twenty normotensive rHuEpo-dependent patients served as a control group. All patients with severe hyperparathyroidism or iron deficiency were excluded. The mean (±SD) haemoglobin concentration was >10 g/dl in all groups. The mean weekly rHuEpo dose increased in the enalapril group (P<0.0001 vs before) and remained constant in the nifedipine and control groups (P=NS vs before). Statistically, there was no differences with regard to iPTH levels, dialysis parameters, iron status, and underlying renal diseases among all groups. Conclusion: High-dose enalapril increases rHuEpo requirement and should be reserved for dialysis patients with hypertension uncontrollable with other antihypertensive medications or dialysis patients with cardiac failure.     

慢性肾功能衰竭对大鼠红细胞生成素受体基因表达的影响

目的研究５／６肾切除引起大鼠慢性肾功能衰竭并出现贫血时骨髓细胞红细胞生成素（ＥＰＯ）受体基因表达的变化。方法用二步法切除５／６肾组织诱发大鼠肾功能衰竭并出现贫血，另以盐酸苯肼导致的急性贫血大鼠和正常大鼠为对照。用ＲＴＰＣＲ检测３组大鼠骨髓有核细胞ＥＰＯ受体ｍＲＮＡ表达，并经灰度扫描，与共扩增的β肌动蛋白基因相比，再用ＳｏｕｔｈｅｒｎＢｌｏｔｉｎｇ证实特异性。结果５／６肾切除后５周大鼠出现明显的肾功能衰竭和贫血。正常大鼠、急性贫血大鼠和肾性贫血大鼠骨髓有核细胞ＥＰＯ受体ｍＲＮＡ表达量分别为０２６±００６、０５１±０２４、０１５±００６，急性贫血大鼠ＥＰＯ受体ｍＲＮＡ表达量高于正常大鼠（Ｐ＜００５），而肾性贫血大鼠明显低于正常大鼠（Ｐ＜００１）。结论大鼠在出现慢性肾功能衰竭并出现贫血时，骨髓有核细胞ＥＰＯ受体ｍＲＮＡ表达明显减少，这可能在慢性肾功能衰竭并发贫血过程中起着一定作用。     

Recombinant human erythropoietin in a patient with multiple myeloma and end-stage renal disease.

Recombinant human erythropoietin (rHuEpo) is an established, effective treatment for the anemia of chronic renal failure. Recent reports also suggest it may be efficacious in the anemias of drug toxicity, rheumatoid arthritis, and multiple myeloma without renal failure. We describe the positive response to rHuEpo in an end-stage renal disease patient with active multiple myeloma and ongoing chemotherapy. Before rHuEpo therapy, the patient was transfusion dependent, but after rHuEpo was initiated, transfusions were not required. Multiple myeloma with renal failure does not preclude a response to rHuEpo. Further trials of rHuEpo in the treatment of multiple myeloma with and without renal failure are warranted.     

Recombinant human erythropoietin treatment protects the cardio-renal axis in a model of moderate chronic renal failure

Chronic kidney disease (CKD) patients develop anemia because of the low kidney erythropoietin (EPO) production, thus promoting cardiovascular complications. The degree of renal insufficiency might determine the moment to start recombinant human erythropoietin (rhEPO) therapy, but the molecular basis for these options deserves better elucidation. This study aimed to clarify the cardio-renal effects of earlier rhEPO therapy in rats with moderate chronic renal failure (CRF). Four groups of rats were evaluated for 15 weeks (control; rhEPO ? 50 IU/kg/week; CRF ? 3/4 nephrectomy; CRF + rhEPO) to assess renal and hematology data, EPO levels, blood pressure, heart rate, peripheral catecholamines contents, serum-transforming growth factor-β1 (TGF-β1), kidney gene expression of EPO, Caspase 9 (Casp9), and vascular endothelial growth factor (Vegf). This model of moderate CRF showed moderate and corrected anemia, hypertension, tachycardia, sympathetic overactivity, and increased serum TGF-β1 content. The remnant kidney showed a proliferative profile, with hypertrophy, downregulated gene expression of EPO, and upregulated gene expression of Vegf and Casp9. rhEPO treatment promoted erythrocytosis and prevented tachycardia and catecholamines increment, with a rise of serum TGF-β1. Furthermore, the decreased kidney gene expression of EPO and the overexpression of Casp9 were prevented, demonstrating a renoprotective action on the remnant kidney. In conclusion, rhEPO therapy promotes a protective effect on the cardio-renal axis, which might be mainly attributed to its pro-proliferative and anti-apoptotic properties. These findings might recommend its use in earlier stages of CRF, acting as an erythropoiesis stimulating agent, to efficiently correct not only the anemia, one of the major complications in these patients, but also the succeeding adverse cardio-renal effects.     

重组人红细胞生成素治疗肾性贫血的疗效分析

目的:探讨不同透析方式影响重组人红细胞生成素的疗效。方法:75例病人分为血液透析、腹膜透析、无透析三组。分别在用药前后测定三组病人的贫血程度(血红蛋白、红细胞、红细胞压积)。结果:同组病人用药前与用药8周后的贫血程度有显著差异性(P<0.01),但三组之间对比无差异性(P>0.05)。结论:提示重组人红细胞生成素治疗肾性贫血有明显效果,但不同透析方式不影响其疗效。     

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.     

Early effects of parathyroidectomy on erythropoietin production in secondary hyperparathyroidism

BACKGROUND: Secondary hyperparathyroidism (2-HPT) has an adverse effect on renal anemia and may cause a hyporesponsiveness to recombinant human erythropoietin (rHuEpo) in patients with chronic renal failure. The early effects of parathyroidectomy (PTx) on renal anemia, erythropoietin production, and nutritional state were examined. METHODS: Twenty-nine patients under hemodialysis therapy received a PTx for 2-HPT. They were prospectively studied regarding hematological parameters, rHuEpo use, plasma erythropoietin levels, and nutritional condition until 12 months after PTx. RESULTS: The hemoglobin level showed a significant increase from 3 months after PTx (10.2% +/- 1.5% to 11.2% +/- 1.3%; P <0.01), associated with a consistent increase of the reticulocyte count. These changes lasted until 12 months after PTx. The plasma erythropoietin level showed a gradual increase of up to about 5 times the level of the preoperative value, until 12 months after PTx (22.6 +/- 10.1 to 106.3 +/- 112.1 mU/mL; P <0.001). The weekly dose of rHuEpo administration decreased after 3 months. The serum levels of albumin and total protein also significantly and gradually improved until 12 months after PTx. CONCLUSIONS: PTx caused a significant early improvement in renal anemia in patients with secondary hyperparathyroidism. This effect may be caused by an enhanced erythropoietin production and may also be partially due to the improved nutritional state after PTx.     

The impact of early normalization of haematocrit by erythropoietin on renal damage in the remnant kidney model

Background: Correction of anaemia in moderate to advanced renal failure is still a matter of debate because of postulated detrimental effects of erythropoietin on the progression of renal damage. Methods: The renal effects of early normalization of haematocrit (Htc) by erythropoietin (rHuEpo) were investigated from the time of 5/6 nephrectomy up to 8 weeks post-intervention in three groups of remnant kidney model rats: untreated controls (CON), rats receiving 100 UI/kg body-wt of rHuEpo i.p. twice a week (EPO), and rats receiving rHuEpo in which periodic phlebotomies maintained Htc similar to the value of the control group (PHL). The latter group was included to evaluate the direct effects of rHuEpo on renal damage, i.e. independent from Htc correction. Results: Two weeks after renal ablation (basal), Htc decreased in CON and PHL (from 49.3±1.4% to 43.2±1.1, P<0.05 and from 49.6±1.1 to 43.3±1.5% P<0.05 respectively), while it remained consistently normal in EPO rats (78.9±1.2% to 48.8±1.5%, P<0.05 vs other groups). Thereafter Htc did not change throughout the remaining period in all groups. At the end of the study, with respect to basal, resting blood pressure increased significantly by the same extent in CON (+13±2%) and EPO rats (+15±5%), while it remained constant in PHL rats. Notably, creatinine clearance significantly decreased in CON (-53±8% vs basal) and EPO (-38±8% vs basal), while it did not change in PHL rats. Likewise the degree of proteinuria as well as renal morphologic alterations and glomerular hypertrophy/sclerosis was similar in CON and EPO rats, and was significantly more severe than in the phlebotomized group. The only difference detected between CON and EPO group was the greater mesangial hypercellularity in rHuEpo-treated rats. Conclusion: In uraemic rats, chronic treatment with rHuEpo aimed at normalization of Htc beginning the early stage of renal failure does not inevitably account for a rise in systemic blood pressure. In addition, neither erythropoietin per se nor the correction of haematocrit accelerates the progression of renal damage when blood pressure remains constant.     

红细胞生成素对慢性肾衰竭大鼠肾小球内皮细胞功能的影响

目的 探讨红细胞生成素（EPO）对慢性肾衰竭（CRF）大鼠肾小球内皮细胞功能的影响。 方法 采用分阶段5/6肾切除术制备大鼠慢性肾衰竭动物模型。实验动物按数字随机法分为4组：假手术组（对照组）、慢性肾衰竭组（模型组）及EPO干预的两个剂量组（小剂量组EPO用量30 U/kg,大剂量组EPO用量50 U/kg）。慢性肾衰竭大鼠皮下注射EPO 6周后处死。检测各组大鼠血肌酐（Scr）、血尿素氮（BUN）、尿蛋白、血红蛋白（Hb）和血压的变化,并观察肾组织病理改变。免疫组化法检测肾小球CD34、CD31表达;RT-PCR检测肾组织内皮素1（ET-1）、内皮细胞一氧化氮合酶（eNOS）和血管内皮细胞生长因子（VEGF） mRNA的表达。 结果 与模型组比较,EPO治疗能显著增加大鼠肾小球CD34、CD31的表达（均P < 0.05）;下调肾组织ET-1 mRNA的表达（P < 0.05）;上调肾组织eNOS和 VEGF mRNA的表达（均P < 0.05）。此外,EPO治疗还能使大鼠Scr、BUN、尿蛋白和血压水平显著降低（均P < 0.05）,Hb水平显著增高（P < 0.05）,肾组织病理损害明显减轻。 结论 EPO能减轻慢性肾衰竭大鼠肾脏的病理损害,改善肾功能。这种作用可能与其促进肾小球内皮细胞的修复和改善内皮功能有关。     

Comparison of the therapeutic efficacy of epoetin beta and epoetin alfa in maintenance phase hemodialysis patients

In May 2009 for financial reasons, the epoetin product used for hemoglobin (Hb) maintenance in our renal dialysis unit was changed from epoetin beta to epoetin alfa. Although widely believed that the dosage requirements are the same, we undertook a retrospective analysis to investigate whether the dosage requirements in chronic renal failure patients were comparable for both preparations. We studied 128 stable end-stage renal failure patients on hemodialysis (three times per week) receiving erythropoietin therapy to maintain their Hb at 11-12.5 g/dL. Patients were excluded if within the study period they developed signs of infection, bleeding, required blood transfusion, were under-dialyzed, or required hospital admission. Regular monthly Hb concentrations and hematocrit (Hct) levels were measured for each patient. The weekly EPO index (defined as weekly epoetin dose/mean monthly Hct) was derived for each patient, before and after regime change. Of the 128 patients in end-stage renal failure, 79 were included in the study. There was no significant difference between the two preparations in terms of Hct level achieved (p = 0.15). However, the median weekly epoetin dose requirement increased from 6733 (range 750-30,000) IU/week to 9000 (250-30,667) IU/week (p < 0.001). EPO index similarly increased from 20,465 (2500-130,846) IU/week/% to 27,073 (729-98,937) IU/week/% (p < 0.001). Our study showed that a higher dose of epoetin alfa was needed to maintain target Hb concentration.     

红细胞生成素对慢性肾衰竭大鼠外周血内皮祖细胞的影响

目的 探讨红细胞生成素（EPO）对慢性肾衰竭大鼠外周血内皮祖细胞（EPC）数量和功能的影响。 方法 采用分阶段5/6肾切除制备大鼠慢性肾衰竭模型。实验动物按数字随机表法分为4组（均n = 7）：假手术组、慢性肾衰竭组（模型组）、30 U/kg EPO干预组（小剂量组）和50 U/kg EPO干预组（大剂量组）。大鼠皮下注射EPO 6周后,取其外周血分离培养EPC,并检测EPC数量及其增殖、黏附和形成血管结构的能力。 结果 与假手术组比较,慢性肾衰竭大鼠外周血EPC数量及其增殖、黏附与形成血管结构的能力均显著下降（均P < 0.05）。应用EPO治疗能显著增加慢性肾衰竭大鼠外周血EPC数量（P < 0.05）,改善外周血EPC增殖、黏附及形成血管结构的能力（均P < 0.05）,并且呈剂量依赖性。 结论 EPO可改善慢性肾衰竭大鼠外周血EPC的数量和功能。     

Erythropoietin resistance as a result of oxalosis in bone marrow

Anemia is an important cause of morbidity in patients suffering from chronic renal failure, and erythropoietin is a milestone of anemia treatment. Various factors may cause erythropoietin resistance. Herein, we describe the case of 32-year-old man who presented with anemia and weakness. He developed progressive renal failure secondary to recurrent kidney stones. One year before admission, he developed anemia for which he had been treated with erythropoietin. However, the anemia persisted. Examination of bone marrow biopsy specimen showed that the marrow was extensively replaced with oxalate crystals and fibrous connective tissue with severe decrease of hematopoietic cells. To the best of our knowledge, our patient represents the first case in the literature describing the association between the oxalate deposition and EPO resistance.     

Transfusion and recombinant human erythropoietin requirements differ between dialysis modalities

Background: Before the routine use of recombinant human erythropoietin (rHuEpo), patients dialysed by peritoneal dialysis (PD) received fewer blood transfusions than patients on haemodialysis (HD). We compared transfusion practices in these groups now that the use of rHuEpo has become standard, while controlling for variables known to influence anaemia of end-stage renal disease (ESRD). Maintenance rHuEpo doses were also compared. Methods: Data were examined for 157 HD and 126 PD patients during a 2-year period. Potential confounders included age, gender, albumin, iron deficiency, parathyroid hormone (PTH), underlying renal disease, cormorbid illness, renal transplant, dialysis adequacy and duration. An intent-to-treat analysis was used, with sensitivity analyses to account for change in treatment and transplant. Results: Mean haemoglobin (Hb) was not different (10.47 g/dl for HD, 10.71 G/DL for PD; P=0.45). Mean monthly transfusion rate was higher for HD (0.47 units per month vs 0.19; P<0.01). More HD patients received at least one transfusion (52.9 vs 40.9%; P<0.01). The maintenance rHuEpo dose was higher for HD (7370 U/week vs 5790 U/week; P=0.01). The only factors associated with risk of being transfused were dialysis duration and mode of dialysis (less risk for PD, odds-ratio 0.57; 95% confidence interval 0.35-0.92). Conclusions: Despite the routine use of rHuEpo, HD patients received more blood and rHuEpo than PD patients to achieve the same Hb. No patient factors were identified to account for this difference. The use of fewer transfusions and less rHuEpo in PD represents an advantage over HD in terms of both cost and safety.     

Effects of different treatment methods on renal anemia in maintenance hemodialysis patients with hyperparathyroidism secondary to uremia

Objective To observe the effects of three treatment methods on renal anemia in maintenance hemodialysis patients with hyperparathyroidism secondary to uremia and analyze the influencing factors of erythropoietin (EPO) dosage. Methods A total of 55 maintenance hemodialysis patients with secondary hyperparathyroidism at the hemodialysis center of Huashan Hospital affiliated to Fudan University from January 2015 to December 2016 were retrospectively divided into three groups according to different treatment methods, parathyroidectomy +forearm transplantation group (surgery group, n=16), cinacalcet treatment group (n=6), and calcitriol treatment group (n=33), respectively. The hemoglobin level and erythropoietin dosage were measured before treatment and in the 3rd month, the 6th month and the 12th month after treatment. The changes of hemoglobin and erythropoietin dosage in the three groups before and after treatment were observed, and the mixed effect model was used to analyze the difference of the change of hemoglobin and erythropoietin dosage among three groups. Multiple linear regression analysis was used to analyze the influencing factors of EPO dosage after one year. Results The levels of intact parathyroid hormone (iPTH) in the surgery group and the cinacalcet group before treatment were significantly higher than that in the calcitriol group (both P＜0.05). In the 12th month after treatment, the levels of iPTH decreased significantly in the patients of surgery group and the cinacalcet group compared with those before treatment (both P＜0.05). The levels of serum alkaline phosphatase, serum calcium and serum phosphorus in the surgery group also decreased significantly compared with those before treatment (all P＜0.05). The mixed effect model analysis showed that the hemoglobin level of surgery group was on an upward trend after the treatment, and the overall level was significantly higher than cinacalcet and calcitriol treatment group (P=0.007). There was no significant difference in the dosage change of erythropoietin (EPO) in the three groups over time. However, the intra-group comparison of the mixed effect model showed that the dosage of EPO in the 12th month was significantly lower than that of before the treatment in surgery group (P=0.007). Multiple linear regression analysis showed that dialysis vintage (B=-0.064, P=0.012) and ferritin ≥ 500 μg/L (B=0.645, P=0.032) were independent influencing factors of EPO dosage. The longer the dialysis vintage, the less EPO dosage, and more EPO dosage were observed in patients with ferritin ≥ 500 μg/L. Conclusions Parathyroidectomy and forearm transplantation is more effective in reducing EPO dosage and improving renal anemia in maintenance hemodialysis patients with secondary hyperparathyroidism. Dialysis vintage and ferritin are independent influencing factors for the dosage of EPO.