Erythropoietin

Suboptimal endogenous erythropoietin response in chronic hepatitis C patients during ribavirin and PEG interferon treatment

BACKGROUND

During the treatment of hepatitis C, anaemia may necessitate pegylated-interferon and ribavirin dose reductions with reduced sustained viral response rates. Although erythropoietic growth factors are frequently used to improve anaemia, it is controversial whether endogenous erythropoietic response is insufficient under these circumstances. We aimed to identify risk factors for more pronounced anaemia and to evaluate endogenous erythropoietic response during antiviral therapy.

METHODS

One hundred and forty-five naive chronic hepatitis C patients on pegylated-interferon-ribavirin treatment were evaluated for haemoglobin, haematocrit, serum ribavirin and erythropoietin levels.

RESULTS

About 99% of patients developed anaemia, with maximal decrease in haemoglobin of 2.5 ± 1.0 mmol/l (range 0.3-5.5 mmol/l). Older age, lower baseline creatinine clearance, higher baseline haemoglobin, more pronounced haemoglobin decrease after 2 weeks and higher week 24 serum ribavirin concentrations were independent risk factors for more pronounced anaemia. Serum erythropoietin levels increased from median 12 IU/l (range 4-63 IU/l) at baseline to 41 IU/l (range 12-683 IU/l) after 12 weeks of therapy and to 43 IU/l (range 7-3238 IU/l) at week 24 (P<0.001). Erythropoietin levels at baseline, week 12 and week 24 negatively correlated with haematocrit. The erythropoietic response to anaemia in our study population was significantly different from the normal human response to anaemia.

CONCLUSION

Older age, lower baseline creatinine clearance, higher baseline haemoglobin, more pronounced haemoglobin decrease after 2 weeks and higher week 24 serum ribavirin concentrations were independent risk factors for more pronounced anaemia during antiviral therapy. Endogenous erythropoietin production is suboptimal during antiviral therapy, supporting use of erythropoietic growth factors.

Alternative procedures for reducing allogeneic blood transfusion in elective orthopedic surgery

Perioperative blood loss is a major problem in elective orthopedic surgery. Allogeneic transfusion is the standard treatment for perioperative blood loss resulting in low postoperative hemoglobin, but it has a number of well-recognized risks, complications, and costs. Alternatives to allogeneic blood transfusion include preoperative autologous donation and intraoperative salvage with postoperative autotransfusion. Orthopedic surgeons are often unaware of the different pre- and intraoperative possibilities of reducing blood loss and leave the management of coagulation and use of blood products completely to the anesthesiologists. The goal of this review is to compare alternatives to allogeneic blood transfusion from an orthopedic and anesthesia point of view focusing on estimated costs and acceptance by both parties.

Erythropoiesis stimulation in acute ischemic syndromes

Erythropoietin (EPO) is a hematopoietic hormone with extensive nonhematopoietic properties. The discovery of an EPO receptor outside the hematopoietic system has fuelled research into the beneficial effects of EPO for various conditions, predominantly in cardiovascular disease. Experimental evidence has revealed the cytoprotective properties of EPO, and it seems that the EPO-EPO receptor system provides a powerful backbone against acute myocardial ischemia, gaining from the different properties of EPO. There is an ongoing discussion about possible discrepancy between preclinical and clinical effects of EPO on the cardiovascular system. Large, randomized, placebo-controlled clinical trials are underway to give a final verdict on EPO treatment for acute coronary syndromes.

Hypothesis: an erythropoietin honeymoon phase exists

TREAT was a recently concluded, and well-powered and designed, study of anemia treatment in chronic kidney disease (CKD). Unlike most previous studies of ESA treatment in nondialysis CKD, TREAT was a placebo-controlled trial. The placebo group in TREAT provides a unique long-term view of a conservative approach to anemia management in nondialysis CKD. The course of mean Hgb levels in the placebo group ran counter to expectations, increasing over time. We discuss possible reasons for this, including a new hypothesis that there may be an erythropoietin 'honeymoon phase' similar to that observed in diabetes mellitus. We propose investigation of this phenomenon as it could lead to less expensive and safer approaches to treatment of CKD anemia.

Erythropoetin receptor expression in the human diabetic retina

Background

Recent evidence suggests erythropoietin (EPO) and the erythropoietin receptor (EPOR) may play a direct role in the pathogenesis of diabetic retinopathy. Better characterization of the EPO-EPOR signaling system in the ischemic retina may offer a new therapeutic modality for ischemic ophthalmic diseases. This study was performed to identify EPOR mRNA expression in the human diabetic eye.

Findings

EPOR antisense RNA probes were validated on human pancreas tissue. In the normal eye, EPOR was expressed in the retinal ganglion cell layer. Minimal expression was observed in the inner and outer nuclear layer. Under conditions of diabetic retinopathy, EPOR expression shifted to photoreceptor cells. Increased expression was also observed in the peripheral retina.

Conclusion

EPOR expression may be a biomarker or contribute to disease mechanisms in diabetic retinopathy.

Androgens and erythropoiesis: past and present

Association between androgens and erythropoiesis has been known for more than seven decades. Androgens stimulate hematopoietic system by various mechanisms. These include stimulation of erythropoietin release, increasing bone marrow activity and iron incorporation into the red cells. Before the discovery of recombinant erythropoietin (rhEpo), androgens were used in the treatment of anemia associated with renal disease, bone marrow suppression, and hypopituitarism. Anabolism is an additional advantage of androgen therapy. Furthermore, in light of recent reports regarding adverse effects of rhEpo, the role of androgen therapy in various types of anemias should be readdressed. Polycythemia remains a known side effect of androgen therapy. In this review, we will briefly discuss the initial animal and human studies which demonstrated the role of androgens in the treatment of anemia, their mechanism of action, a detailed account of the efficacy of androgens in the treatment of various anemias, the erythropoietic side effects of androgens and finally, the relationship between hematocrit levels and cardiovascular disease.

Erythropoietin in cardiac disease: new features of an old drug

Erythropoietin is a haematopoietic hormone with extensive non-haematopoietic effects. The discovery of an erythropoietin receptor outside the haematopoietic system has fuelled the research into the beneficial effects of erythropoietin for various conditions, predominantly in cardiovascular disease. Experimental evidence has revealed the cytoprotective and angiogenic properties of erythropoietin and it seems that the erythropoietin-erythropoietin receptor system provides a powerful backbone against acute and chronic myocardial ischemia, each gaining from the different properties of erythropoietin. Clinical trials in which erythropoietin was titrated to achieve certain haematocrit levels have generated equivocal results. It has been suggested that a (too) high haematocrit is undesirable in cardiovascular disease. We have shown that intermittent (low-dose) erythropoietin administration, that does not increase haematocrit substantially, suffices to activate the beneficial downstream pathways of erythropoietin. We postulate that intermittent administration or a lower than conventional dose of erythropoietin, not only aimed at increasing haemoglobin at high levels, will provide powerful cellular protection and will improve cardiac outcome, without the side effects of erythropoietin associated with increased haematocrit.

Mechanism of increased mortality risk with erythropoietin treatment to higher hemoglobin targets

Recent randomized, controlled trials indicate that there is a strong trend for increased risk for death or adverse composite outcomes with erythropoiesis-stimulating agent treatment in kidney disease to hemoglobin targets higher than those currently recommended. The failure of these trials to find a benefit of higher hemoglobin is in stark contrast to findings from large, observational, population-based studies that continue to demonstrate the association of low hemoglobin with adverse outcomes. The mechanisms for the adverse effect of higher hemoglobin targets that are seen in the randomized, controlled trials are poorly understood. This review explores hypotheses involving (1) the effect of achieved hemoglobin itself, (2) the role of erythropoiesis-stimulating agent treatment, (3) the use of iron supplementation, (4) increased blood pressure, and (5) erythropoiesis-stimulating agent hyporesponsiveness. Because the causal pathway has yet to be determined, further research is strongly encouraged. Clinical practice, however, should avoid erythropoiesis-stimulating agent treatment to higher hemoglobin targets, particularly in those with significant cardiovascular morbidity and those who require disproportionately high dosages of erythropoietin-stimulating agents to achieve recommended hemoglobin levels.

Prevalence, etiology, and consequences of anemia and clinical and economic benefits of anemia correction in patients with chronic kidney disease: an overview

PURPOSE

The prevalence of chronic kidney disease (CKD) and anemia in the United States, classification scheme for CKD, definition of anemia, etiology and consequences of anemia in patients with CKD, and the clinical and economic benefits of correcting anemia are described.

SUMMARY

Approximately 20 million people in the United States population have CKD, and 2-4 million of these may also have anemia, which often goes undetected and untreated. Patients with CKD are now classified into five stages based on the degree of kidney function impairment. Here, anemia is caused by insufficient erythropoietin production, and may occur as early as stage 3 CKD. Potential consequences of anemia include cognitive impairment, angina, and the cardiorenal anemia syndrome, a triad of worsening anemia, worsening CKD, and worsening congestive heart failure. Treatment of anemia in predialysis patients with stage 2-4 CKD may slow renal disease progression and improve energy, work capacity, health-related quality of life, and cardiac function. Optimizing the hemoglobin or hematocrit value before initiating dialysis may reduce mortality. Anemia contributes to significant healthcare costs associated with CKD. Substitution of the subcutaneous route of administration for the intravenous route of administration for epoetin alfa can reduce drug acquisition and healthcare costs, the two largest components of healthcare costs in CKD patients. Efforts to slow the progression of CKD could also have a substantial impact on hospitalizations and costs.

CONCLUSION

Correcting anemia has the potential to improve clinical and economic outcomes in patients with CKD.

The Role of the Kidney in Blood Volume Regulation: The Kidney as a Regulator of the Hematocrit

The kidney plays a pivotal role in the regulation of blood volume by controlling the plasma volume and red blood cell (RBC) mass. Further, it is proposed that the kidney coordinates the relative volumes of these 2 blood components and in so doing regulates the hematocrit. This novel function as proposed is a functional concept whereby the kidney does not simply produce erythropoietin, but that the kidney regulates the hematocrit is termed the critmeter function. The kidney is unique in that it can indirectly report on blood volume as a tissue oxygen signal. It is proposed that the kidneys detect small changes in tissue oxygen tension for erythropoietin production at the critmeter, a functional unit of marginal oxygen tension within the kidneys. As the production of erythropoietin is modulated by angiotensin II, the renin-angiotensin system entrains the production of erythropoietin as part of the effector signals of the feedback loop of blood volume regulation. Collectively, the consideration of these points generates a paradigm shift in our understanding of blood volume regulation in that the role of the kidney may be expanded from simply "producing" erythropoietin to regulating the hematocrit. Further, this concept broadens the scope of the traditionally identified effector mechanisms of plasma volume regulation to include the modulation of erythropoietin production and hence RBC mass. The inclusion of both plasma volume and RBC mass as factors targeted by the effector signals recapitulates that whole blood volume is sensed and reported in the afferent signals. In summary, distinct sensing and effector mechanisms for regulating the volume of the two components of whole blood (plasma and red cell mass) are recognized. The coupling of the regulation of these 2 components of blood volume is highlighted.

[Anemia induced by cadmium intoxication]

Anemia is commonly induced by chronic cadmium (Cd) intoxication. Three main factors are involved in the development of Cd-induced anemia: hemolytic, iron-deficiency, and renal. Intravascular hemolysis can occur at the early stage of Cd exposure owing to the direct damaging effect on erythrocytes. In addition, Cd that accumulates in erythrocytes affects membrane cytoskeletons and decreases cell deformability, and these cells are then trapped and destroyed in the spleen. Iron deficiency can be detected in animals after an oral exposure to Cd, which competes with iron for absorption in the intestines, leading to anemia. However, an increase in body iron content along with anemia is often observed in cases of parenteral exposure or itai-itai disease. Therefore, it is estimated that Cd disrupts the efficient usage of iron in hemoglobin synthesis in the body. Renal anemia is observed during the very last phase of chronic, severe Cd intoxication, such as itai-itai disease, showing a decrease in the production of erythropoietin from renal tubular cells. Because the renal anemia is based on the same pathophysiology as Cd-induced osteomalacia, which is derived from the disturbance of mineral metabolism due to renal tubular dysfunction, it is reasonable to include renal anemia in the criteria for the diagnosis of itai-itai disease. Hemodilution could also contribute to the development of Cd-induced anemia. Bone marrow hypoplasia or the inhibition of heme synthesis might only be involved in Cd-induced anemia in severe cases of Cd intoxication.

Polycythemia and increased erythropoietin in a patient with chronic kidney disease

BACKGROUND

A 16-year-old white male with a history of obstructive uropathy presented to a pediatric outpatient clinic with a first syncope. At presentation, he had a hemoglobin level of 220 g/l, a serum erythropoietin level of 27.4 U/l and a serum creatinine level of 200.7 micromol/l (2.27 mg/dl).

INVESTIGATIONS

Physical examination, serum laboratory analysis, renal ultrasound, MRI, and 99mTc-MAG3 scintigraphy of the kidneys.

DIAGNOSIS

Chronic renal insufficiency caused by obstructive hydronephrosis and accompanied by increased erythropoietin levels of renal origin and polycythemia.

MANAGEMENT

Serial phlebotomies and laparoscopic removal of the right hydronephrotic kidney.

Pre-operative predeposit autologous donation in children presenting for elective surgery: a review

Predeposit Autologous blood donation (PAD) in children decreases the life-time complications associated with allogeneic blood. These complications include transmission of known or unknown pathogens and alloimmunization against future blood transfusions, organ transplants and pregnancies. In view of the potential long term benefits of PAD should it be considered a component of paediatric blood conservation programs. This paper reviews the literature to explore the risk of benefit analysis of adopting PAD in paediatric practice.

Recombinant human erythropoietin for the treatment of anaemia in patients with chronic idiopathic myelofibrosis

BACKGROUND

Patients with chronic idiopathic myelofibrosis (CIMF) usually present with anaemia. Treatment is often palliative and the majority of patients receive regular red blood cell (RBC) transfusions. Although recombinant human erythropoietin (rhu-EPO) has been proved effective for the treatment of anaemia in several chronic diseases, including haematological malignancies, its role in the treatment of the anaemia in CIMF is not well established. We report the beneficial effect of rhu-EPO administration in 20 patients with CIMF and discuss the parameters predicting favourable response.

PATIENTS

Twenty patients with CIMF (9 women and 11 men) regularly treated with supportive RBC transfusions were included in the study. The median age was 70 years (range 45-81 years). Rhu-EPO, 10,000 U, was given subcutaneously 3 times a week. The median duration of therapy was 83 months, ranging from 13 to 87 months.

RESULTS

Treatment was considered effective if haemoglobin levels increased over 2 g/dl within 12 weeks after enrolment or the RBC transfusion requirements were reduced by 50% within the same interval. Twelve patients (60%) responded to therapy. Responders were mainly female, had smaller spleen size (p = 0.024), low RBC transfusion requirements (< or = 1-2 units per month), and significantly lower endogenous serum erythropoietin (EPO) and beta2-microglobulin (beta2-M) levels when compared with non-responders (p < 0.0001 and 0.00001, respectively). Treatment was well tolerated and none of the patients was withdrawn from the treatment protocol because of side effects.

CONCLUSIONS

Rhu-EPO administration is an effective, safe and well-tolerated treatment for patients with CIMF and anaemia leading to a significant reduction in RBC transfusion requirements. Factors predicting favourable response are low endogenous EPO and beta2-M serum levels and slight to moderate splenomegaly.

The Use of Erythropoietin in Patients Undergoing Radical Prostatectomy: Effects on Hematocrit, Transfusion Rates and Quality of Life

OBJECTIVE

It was the aim of this study to prospectively study the effects on hematocrit levels, transfusion rates and quality of life (QOL) indices in men preoperatively supplemented with recombinant erythropoietin (rEPO) undergoing radical prostatectomy for clinically localized prostate cancer.

METHODS

Thirty men undergoing radical prostatectomy were randomized either to receive rEPO (n=25) or to serve as controls (n=25). Outcome measurements obtained preoperatively, as well as 10 days and 6 weeks postoperatively included serum hematocrit levels, transfusion rates and QOL indices (using SF-12 validated questionnaires).

RESULTS

The rEPO group had a significant increase in preoperative hematocrit (median increase=4 points; p=0.002). Although there were no significant differences in hematocrit at 10 days, the rEPO had a significantly higher hematocrit value at 6 weeks (p=0.0086). No differences were observed in transfusions rates between groups (4% in each group). SF-12 mental and SF-12 physical scores were not different between the two groups at any time point.

CONCLUSION

Preoperative administration of rEPO significantly increases preoperative and postoperative hematocrit levels. However, no differences were observed with regard to transfusion rates or postoperative QOL indices despite these higher hematocrit values.

Correlation between Fractional Reabsorption of Sodium and Erythropoietin dose in Peritoneal Dialysis Patients

Background

Erythropoietin (EPO) deficiency of chronic renal failure (CRF) may be a functional consequence of decreased glomerular filtration rate and fractional reabsorption of sodium (FRNa). Decreased FRNa reduces renal oxygen consumption and increases tissue oxygen pressure, resulting in less EPO production. We hypothesized that, in CRF patients, there is a positive relationship between EPO production and FRNa and that, in such patients receiving EPO, a negative correlation is expected between FRNa and EPO dose.

Methods

Creatinine clearance, FRNa, serum iron, transferrin, transferrin saturation, ferritin, and intact parathyroid hormone (iPTH) levels were measured in 91 peritoneal dialysis patients. The correlation between EPO dose and FRNa was studied.

Results

Mean EPO dose was 7076 ± 4821 units/week and mean FRNa was 93.40% ± 6.14%. A negative correlation was found between EPO dose and FRNa ( r = -0.28, p < 0.01), and a positive correlation was found between both ferritin and iPTH and EPO dose ( r = 0.39, p < 0.001 and r = 0.35, p < 0.002 respectively). After adjusting for the effect of creatinine clearance, ferritin, and iPTH, there was still a significant correlation between EPO dose and FRNa ( p < 0.05).

Conclusion

In CRF patients there is a negative correlation between FRNa and EPO dose, which supports the hypothesis that EPO deficiency may be related to the decreased renal oxygen-consuming work of sodium reabsorption.

A sample distribution programme for erythropoietin

A survey was sent to laboratories participating in the United Kingdom External Quality Assessment Service (UKNEQAS) Haematinics Scheme about the measurement of serum erythropoietin (EPO). Six laboratories, from a total of 120 that returned the survey, were measuring serum EPO concentrations by commercially available immunoassays on site in the United Kingdom. The workload of the laboratories varied from up to 100 specimens per month to more than 100 specimens analysed per week. All laboratories included control material in the assays and none of the laboratories was participating in an external quality assessment scheme for serum EPO. Four laboratories agreed to take part in the first sample distribution programme, with five and six laboratories participating in distributions 2 and 3 respectively. The results from eight kits were compared from the three distributions over a 2-year period. The serum EPO concentrations for the methods showed some variation across the range of 2.9-200 U/l when the serum EPO concentrations for each method were compared with the whole method mean. The results from this scheme have identified a role for an external quality assessment scheme for serum EPO measurements.

Does the Use of Erythropoietin Reduce the Risk of Exposure to Allogeneic Blood Transfusion in Cardiac Surgery? A Systematic Review and Meta-Analysis

BACKGROUND

The use of blood conservation techniques is important in cardiac surgery as postoperative bleeding is common and allogeneic blood transfusion carries the risk of transfusion reactions and infection transmission. Erythropoietin with and without preoperative autologous blood donation is one of the modalities to avoid allogeneic blood transfusion. The objective of this review was to assess the effectiveness of erythropoietin in reducing the risk of exposure to allogeneic blood transfusion during or after cardiac surgery.

METHODS

A meta-analysis of 11 identified randomized controlled trials, reporting comparisons between erythropoietin and control, was undertaken. The primary outcome was the number of patients exposed to allogeneic blood transfusion during or after cardiac surgery.

RESULTS

Eleven studies, involving 708 patients, met the inclusion criteria for this review. In total, 471 patients were given erythropoietin, and 237 patients formed the control group. The administration of erythropoietin with and without preoperative autologous blood transfusion prior to cardiac surgery is associated with a significant risk reduction: RR = 0.28 (95% CI 0.18-0.44, P < 0.001) and RR = 0.53 (95% CI 0.32-0.88, P < 0.01), respectively.

CONCLUSION

The administration of erythropoietin before cardiac surgery is associated with a significant reduction in the risk of exposure to allogeneic blood transfusion. Further studies are warranted to define the patients' subgroups that may benefit the most from EPO administration.

Effects of recombinant human erythropoietin injections on physical self in endurance athletes

This study examined the time course of mean self-esteem and physical self scores in three groups: male endurance athletes treated with recombinant human erythropoietin (rHuEPO group, n = 6), a placebo group (n = 5) injected with a sodium chloride solution and a control group who did not receive any injection (n = 6). Each participant completed the Physical Self Inventory twice a day (between 07.00 and 09.00 h and between 19.00 and 21.00 h). Using a 10 cm visual analog scale, the participants assessed global self-esteem, physical self-worth and the sub-domains of physical condition, sport competence, attractive body and physical strength (Fox & Corbin, 1989). This was conducted over three consecutive periods: in the 2 weeks before the course of injections, during the 6 weeks of injections and for 4 weeks after the injections. Aerobic capacity was assessed before and after 4 weeks of treatment. The results showed a significant increase in aerobic physical fitness in the rHuEPO group and a significant increase in perceived physical condition and physical strength scores at the end of treatment. The main psychological result was that endurance athletes were highly sensitive to the effects of rHuEPO on physical fitness. The perception of increased physical condition may lead to a stronger commitment to training. The rHuEPO injections presented a dangerous hedonic effect linked to endurance training. These results confirm the need to tackle rHuEPO abuse at any time during the training season.

Serum erythropoietin levels in septic shock

Erythropoietin is a glycoprotein hormone mainly released by the kidney, which stimulates red blood cell production. However, in sepsis, the mechanisms responsible for the final increase in circulating erythropoietin remain unclear Seventeen critically ill patients with Simplified Acute Physiologic Score average 66 (range 43 to 103) were included in this study. Ten patients survived and seven died within 28 days. Blood samples obtained at different times were assayed for erythropoietin, cytokine levels and lactate measurements. PCO2 gap was assessed to detect the presence of gastric mucosal acidosis. Erythropoietin decreased in the patients who survived while it remained high or increased in non-survivors (37+/-6.5 vs 147+/-6. 7 UI/l respectively, P<0.05). Erythropoietin plasma levels were correlated with IL-6 levels (r=0.84, P<0.05) and TNFalpha levels (r=0.84, P<0.05). We observed a significant positive relationship between erythropoietin plasma levels and lactate concentrations (r= 0.89, P< 0. 05) and with PCO2 gap (r=0.9, P < 0.05). No correlation was found between erythropoietin concentration and the other parameters. High serum erythropoietin levels in non-survivors were observed with septic shock despite an increase in the levels of proinflammatory cytokines. We found a relationship between erythropoietin concentration and biological markers of tissue hypoperfusion i.e. lactate levels or PCO2 gap. This relationship could suggest tissue hypoperfusion as the stimulating factor for erythropoietin production in septic shock.

Utilisation de l'érythropoïétine recombinante humaine chez l'enfant atteint de cancer

Eighty percent of children with cancer suffer from anemia at the time of diagnosis. The physiopathology of anemia is complex. Although anemia can be life threatening, its consequences on the physical, psychological and social state of the child are often minimized. Blood transfusion is the main treatment of anemia: its efficacy is immediate but shortlasting, and it involves infectious and hemolytic risks. The human recombinant erythropoietin has been used for more than 25-years, and is often prescribed to adults with cancer and anemia. The human recombinant erythropoietin rHuEPO is nowadays used when blood transfusion is contra-indicated because of religious or cultural considerations, although several promising studies have been conducted about rHuEPO and children with cancer since 1996: it might be soon the preferential alternative treatment to anemia in children with cancer.

Serum Erythropoietin and Aging: A Longitudinal Analysis

OBJECTIVES

To determine the changes in serum erythropoietin with age in patients with and without anemia and to assess the importance of certain comorbidities on changes in erythropoietin level and the development of anemia.

DESIGN

Clinical history, hematological parameters, and serum erythropoietin levels were examined at 1- to 2-year intervals for 8 to 30 years.

SETTING

Baltimore Longitudinal Study on Aging (BLSA), National Institute on Aging.

PARTICIPANTS

One hundred forty-three BLSA participants.

MEASUREMENTS

Complete blood count and serum chemistries were performed at the time of each visit, and archived serum samples were used for erythropoietin level.

RESULTS

Although all subjects were healthy and without anemia at the time of initial evaluation, some developed chronic illness-most notably hypertension and diabetes mellitus. Erythropoietin levels rose significantly for the group as a whole, and the slope of the rise was found to be greater for those who did not have associated diabetes mellitus or hypertension. During the subsequent years, subjects who developed anemia but did not have hypertension or diabetes mellitus had the greatest slope in erythropoietin rise over time, whereas those with hypertension or diabetes mellitus and anemia had the lowest erythropoietin slope.

CONCLUSION

The increase in serum erythropoietin with aging may be compensation for subclinical blood loss, increased red blood cell turnover, or increased erythropoietin resistance of red cell precursors. It is suspected that, with very advanced age, or in those with compromised renal function (e.g., diabetes mellitus or hypertension), the compensatory mechanism becomes inadequate and anemia results.

Erythropoietin response in critically ill mechanically ventilated patients: a prospective observational study

Introduction

Anemia is a common problem in critically ill patients. The etiology of anemia of critical illness is often determined to be multifactorial in the clinical setting, but the pathophysiology remains to be elucidated. Erythropoietin (EPO) is an endogenous glycoprotein hormone that serves as the primary stimulus for erythropoiesis. Recent evidence has demonstrated a blunted EPO response as a factor contributing to anemia of critical illness in specific subsets of patients. Critically ill patients requiring mechanical ventilation who exhibit anemia have not been the subject of previous studies. Our goal was to evaluate the erythropoietic response to anemia in the critically ill mechanically ventilated patient.

Methods

A prospective observational study was undertaken in the medical intensive care unit of a tertiary care, military hospital. Twenty patients admitted to the medical intensive care unit requiring mechanical ventilation for at least 72 hours were enrolled as study patients. EPO levels and complete blood count were measured 72 hours after admission and initiation of mechanical ventilation. Admission clinical and demographic data were recorded, and patients were followed for the duration of mechanical ventilation. Twenty patients diagnosed with iron deficiency anemia in the outpatient setting were enrolled as a control population. Control patients had baseline complete blood count and iron panel recorded by primary care physicians. EPO levels were measured at the time of enrollment in conjunction with complete blood count.

Results

The mean EPO level for the control population was 60.9 mU/ml. The mean EPO level in the mechanically ventilated patient group was 28.7 mU/ml, which was significantly less than in the control group (P = 0.035). The mean hemoglobin value was not significantly different between groups (10.6 g/dl in mechanically ventilated patients versus 10.2 g/dl in control patients; P > 0.05).

Conclusion

Mechanically ventilated patients demonstrate a blunted EPO response to anemia. Further study of therapies directed at treating anemia of critical illness and evaluating its potential impact on mechanical ventilation outcomes and mortality is warranted.

Vascular endothelial growth factor and its soluble receptor, Flt-1, are not correlated to erythropoietin in diabetics with normal or reduced renal function

BACKGROUND AND AIMS

Recombinant erythropoietin upregulates the expression of the vascular endothelial growth factor (VEGF) receptors, Flt-1 (VEGFR-1) and KDR/Flk-1 (VEGFR-2), in endothelial cells. The integrity of the VEGF system seems to be crucial for the regulation of endothelial permeability and thus for the avoidance of renal protein leakage. As albuminuria/proteinuria is a hallmark of diabetic nephropathy, we examined cross-sectionally in 35 type 1 and 37 type 2 diabetic patients with various degrees of renal dysfunction and albuminuria whether there was an interrelationship between intrinsic erythropoietin (EPO) and VEGF/Flt-1.

METHODS AND RESULTS

In patients with plasma creatinine values < or =1.5 (n = 53) or >1.5 mg/dL (n = 19), the mean serum EPO was 5.6 +/- 4.4 and 10.2 +/- 7.0 mU/mL (P = 0.02), respectively. In the two groups, urinary and serum VEGF(165) concentrations were similarly distributed (mean 94.3 +/- 91.8 vs 108 +/- 72.2 ng/L and 91.7 +/- 76.8 vs 91.9 +/- 74.9 ng/L, respectively; both P = NS). The mean urinary Flt-1 for the two groups amounted to 0.14 +/- 0.35 and 0.51 +/- 0.93 ng/mL (P = 0.045), respectively. No correlation between VEGF or Flt-1 and EPO was apparent.

CONCLUSION

Our data suggest that in vivo EPO does not affect the functionality and/or production of components of the VEGF/Flt-1 system in diabetics with normal or reduced renal function.

Expression, bioactivity, and clinical assessment of recombinant feline erythropoietin

OBJECTIVE

To determine the activity of recombinant feline erythropoietin (rfEPO) in murine bioassays and evaluate its efficacy and safety in cats with erythropoietin-dependent nonregenerative anemia.

ANIMALS

26 cats (group 1, 19 cats with anemia attributed to chronic kidney disease [CKD]; group 2, 7 cats with CKD and recombinant human erythropoietin [rhEPO]-induced red cell aplasia [RCA]).

PROCEDURE

The rfEPO was synthesized by use of Chinese hamster ovary (CHO) cells transfected with feline erythropoietin complementary DNA. Preclinical assessments of rfEPO included an erythroid cell proliferation assay and measurements of reticulocytosis in Balb/C mice. Clinical assessments of cats included hematologic, biochemical, and clinical examinations during 12 (group 1) or 6 (group 2) months of rfEPO treatment.

RESULTS

Biological activity of rfEPO was broadly equivalent to rhEPO in preclinical murine bioassays. Median Hct and absolute reticulocyte count in cats increased significantly during the first 3 weeks of rfEPO treatment, and median Hct generally could be maintained within a target range of 30% to 40% with periodic adjustments of rfEPO doses. Unexpectedly, 5 cats in group 1 and 3 cats in group 2 that initially responded to rfEPO treatment again developed anemia that was refractory to additional rfEPO treatments, even at higher doses.

CONCLUSIONS AND CLINICAL RELEVANCE

Treatment with rfEPO can reestablish active erythropoiesis in most cats with CKD, even those with anemia attributable to rhEPO-induced RCA. Unfortunately, development of RCA during treatment with CHO cell-derived recombinant erythropoietin proteins was not eliminated as a serious safety concern, even for this feline-specific preparation.

The regulated long-term delivery of therapeutic proteins by using antigen-specific B lymphocytes

Memory lymphocytes are important mediators of the immune response. These cells are long-lived and undergo clonal expansion upon reexposure to specific antigen, differentiating into effector cells that secrete Ig or cytokines while maintaining a residual pool of memory T and B lymphocytes. Here, the ability of antigen-specific lymphocytes to undergo repeated cycles of antigen-driven clonal expansion and contraction is exploited in a therapeutic protocol aimed at regulating protein delivery. The principle of this strategy is to introduce genes encoding proteins of therapeutic interest into a small number of antigen-specific B lymphocytes. Output of therapeutic protein can then be regulated in vivo by manipulating the size of the responder population by antigen challenge. To evaluate whether such an approach is feasible, we developed a mouse model system in which Emu- and Iglambda-based vectors were used to express human erythropoietin (hEPO) gene in B lymphocytes. These mice were then immunized with the model antigen phycoerythrin (PE), and immune splenocytes (or purified PE-specific B lymphocytes) were adoptively transferred to normal or mutant (EPO-deficient) hosts. High levels of hEPO were detected in the serum of adoptively transferred normal mice after PE administration, and this responsiveness was maintained for several months. Similarly, in EPO-deficient anemic recipients, antigen-driven hEPO expression was shown to restore hematocrit levels to normal. These results show that antigen-mediated regulation of memory lymphocytes can be used as a strategy for delivering therapeutic proteins in vivo.

Does autonomic neuropathy play a role in erythropoietin regulation in non-proteinuric Type 2 diabetic patients?

AIMS

Erythropoietin (EPO)-deficient anaemia has been described in Type 1 diabetic patients with both severe autonomic neuropathy (AN) and proteinuria. This study was aimed at distinguishing between the effects of AN and nephropathy on haemoglobin and EPO levels in Type 2 diabetic patients at an early stage of diabetic nephropathy.

METHODS

In 64 Type 2 diabetic patients (age 52 +/- 10 years, duration 10 +/- 9 years) without overt nephropathy and other causes of anaemia or EPO deficit, we assessed cardiovascular tests of AN, 24-h blood pressure (BP) monitoring, urinary albumin excretion rate (UAE), a full blood count, and serum EPO.

RESULTS

Although the Type 2 diabetic patients with AN did not show differences in haemoglobin and EPO when compared with patients without AN, the presence of haemoglobin < 13 g/dl was associated with the presence of AN (chi(2)= 3.9, P < 0.05) and of postural hypotension (chi(2)= 7.8, P < 0.05). In a multiple regression analysis including as independent variables gender, body mass index, duration of diabetes, smoking, creatinine, 24-h UAE, 24-h diastolic BP, ferritin, erythrocyte sedimentation rate, and autonomic score, we found that the only variables independently related to haematocrit were autonomic score, ferritin and erythrocyte sedimentation rate. Finally, the physiological inverse relationship between EPO and haemoglobin present in a control group of 42 non-diabetic non-anaemic subjects was completely lost in Type 2 diabetic patients. The slopes of the regression lines between EPO and haemoglobin of the control subjects and the Type 2 diabetic patients were significantly different (t = 14.4, P < 0.0001).

CONCLUSIONS

This study documents an early abnormality of EPO regulation in Type 2 diabetes before clinical nephropathy and points to a contributory role of AN in EPO dysregulation.

The significance of serum erythropoietin levels in assessing the severity of renal damage in children with reflux nephropathy

PURPOSE

Erythropoietin (EPO) is the principal factor regulating red blood cell production in humans. It has been shown that EPO gradually decreases with the progression of diabetic nephropathy and may be used as a marker of severity of disease. In vitro studies have shown that interleukin-10 (IL-10) acts synergistically with EPO to increase stimulation of erythroid differentiation and proliferation. We evaluate serum levels of EPO and IL-10 in children with reflux nephropathy (RN).

MATERIALS AND METHODS

Serum level of EPO and IL-10 were measured in 32 girls and 22 boys with RN, and in 22 boys and 10 girls who served as healthy controls. Renal scarring was evaluated with Technetium dimercapto-succinic acid scan. RN was severe (less than 20% uptake) in 16 children, moderate (20% to 40% uptake) in 25 and mild RN (greater than 40% uptake) in 13. Because anemia may further stimulate EPO production we also compared the index Hb (hemoglobin) x EPO in all patients. IL-10 and EPO were measured with standard enzyme-linked immunosorbent assay technique. The unpaired t test was used for statistical analysis.

RESULTS

There were no statistically significant differences in the serum levels of EPO in children with RN (6.11 +/- 0.51 mIU/ml) compared to controls (6.42 +/- 0.46 mIU/ml) (p >0.5). Similarly the index Hb x EPO was 75.25 +/- 5.65 in children with RN compared to 73.76 +/- 5.48 in controls. Mean EPO levels were similar for mild, moderate and severe RN. There was no difference in the serum levels of IL-10 in children with RN (23.14 +/- 2.32 pg/ml) compared to controls (22.67 +/- 4.13 pg/ml) (p >0.5).

CONCLUSIONS

Although EPO has been reported to be a marker of progressive renal disease in diabetic nephropathy, our data indicate that serum levels of EPO do not reflect the severity of renal parenchymal damage in children with RN.

Mechanisms and Treatment of Anemia in Chronic Heart Failure

Anemia is highly prevalent in patients with chronic heart failure (HF) and is associated with poor clinical outcomes. Multiple mechanisms contribute to anemia in chronic HF, and subnormal compensatory rise in endogenous erythropoietin levels in response to anemia is one contributory factor. Randomized trials with recombinant human erythropoietin therapy in anemic patients with chronic kidney disease and concomitant heart disease have demonstrated a reduction in left ventricular hypertrophy but variable effects on clinical outcome. Preliminary clinical trials in anemic patients with chronic HF demonstrate that erythropoietin therapy is well tolerated and associated with short-term clinical improvement. The optimum target hemoglobin, erythropoietic agent, and dosing regimen, and the role of iron supplementation in patients with chronic HF, are not known. Additional studies are needed to determine the safety and efficacy of long-term erythropoietic therapy in chronic HF patients.

Subnormal rise of erythropoietin in patients receiving interferon and ribavirin combination therapy for hepatitis C

OBJECTIVES

Anemia is a common complication during interferon-ribavirin therapy for hepatitis C. While normally a fall in hematocrit in results in an exponential compensatory rise in erythropoietin, such that the correlation between hematocrit and erythropoietin is sharply negative, the erythropoietin response during interferon-ribavirin combination therapy is not known.

METHODS

We measured the hematocrit and erythropoietin levels before and after about 4 weeks of interferon-ribavirin therapy for hepatitis C (n = 43), and compared their relation to the normal human response to anemia.

RESULTS

The hematocrit fell from an average pre-treatment level of 43.7 +/- 3.7% to 36.9 +/- 5 (P < 0.0001). The erythropoietin level rose from 14.5 +/- 15.1 to 58.5 +/- 94.1 units/L (P < 0.0001), indicating there was an adequate stimulus for erythropoietin release. The rise of erythropoietin was severely impaired in relation to the normal human response to a fall in hematocrit. Using the normal human response to anemia as the population line, for our population there was a significant difference in the slope of hematocrit (x) versus log10 erythropoietin (y) (-8.7 vs. -3.098 respectively, P < 0.001) and y-intercept (4.609 vs. 2.753 respectively, P < 0.001). The Bonferroni adjusted "p" value was derived to be <0.002. There was an approximate 2 log10 reduction in maximal achievable erythropoietin level in subjects exposed to interferon-ribavirin combination.

CONCLUSION

There is a subnormal rise of erythropoietin after interferon-ribavirin combination therapy for hepatitis C.

Cerebral sinovenous thrombosis in children: another reason to treat iron deficiency anemia

Iron deficiency anemia is a rare cause of cerebral sinovenous thrombosis in children. We report three cases of cerebral sinovenous thrombosis and iron deficiency anemia treated at Primary Children's Medical Center in Salt Lake City, Utah, between 1998 and 2001. The children were 9, 19, and 27 months old at the time of admission. Hemoglobin levels ranged from 6.6 to 7.0 g/dL, mean corpuscular volume levels from 45 to 56 fL, and platelet counts from 248,000 to 586,000/microL. Magnetic resonance imaging and magnetic resonance venography revealed thrombosis of the straight sinus and internal cerebral veins in all three children, with the addition of the vein of Galen, left transverse and sigmoid sinuses, and upper left internal jugular vein in one child. Recovery ranged from excellent to poor in 3 months to 3 years of follow-up. Four additional cases, ages 6 to 22 months, were found in the English-language literature. Evaluation for prothrombotic disorders was negative in all children, including the current cases. Treatments have included thrombectomy, corticosteroids, mannitol, heparin, low-molecular-weight heparin, warfarin, aspirin, blood transfusion, and iron supplementation, but there is no consensus regarding therapy, other than to correct the anemia and treat iron deficiency. Iron deficiency anemia, a preventable cause of cerebral sinovenous thrombosis, deserves consideration when cerebral sinovenous thrombosis is detected in young children.

Injections of recombinant human erythropoietin increases lactate influx into erythrocytes

Previous studies showed that erythropoietin not only increases erythrocyte production but is also essential in both the synthesis and the good functioning of several erythrocyte membrane proteins, including band 3. It is still unknown whether anion and/or H(+) fluxes are modified by erythropoietin. This study aimed to evaluate the effect of recombinant human erythropoietin (rHuEPO) injections on lactate transport into erythrocytes via band 3 and H(+)-monocarboxylate transporter MCT-1, two proteins involved in lactate exchange. Nine athletes received subcutaneous rHuEPO (50 U/kg body mass 3 times a week for 4 wk), and seven athletes received a saline solution (placebo group). All subjects were also supplemented with oral iron and vitamins B(9) and B(12). Lactate transport into erythrocytes was studied before and after the rHuEPO treatment at different lactate concentrations (1.6, 8.1, 41, and 81.1 mM). After treatment, MCT-1 lactate uptake was increased at 1.6, 41 (P < 0.01), and 81.1 mM lactate concentration (P < 0.001) although lactate uptake via band 3 and nonionic diffusion were unchanged. MCT-1 maximal velocity increased in the rHuEPO group (P < 0.05), reaching higher values than in the placebo group (P < 0.05) after treatment. Our results show that rHuEPO injections increased MCT-1 lactate influx at low and high lactate concentrations. The increase in MCT-1 maximal velocity suggests that rHuEPO may stimulate MCT-1 synthesis during erythrocyte formation in bone marrow.

Treatment of anemia in patients with chronic heart failure

Anemia occurs frequently in chronic heart failure (CHF) patients and is associated with increased morbidity and mortality risk. Clinical trials with recombinant human erythropoietin in patients with chronic kidney disease and concomitant structural heart disease have demonstrated beneficial effects on ventricular remodeling but variable effects on clinical outcome. Preliminary clinical trials in patients with CHF demonstrate that erythropoietin therapy is well-tolerated and associated with short-term clinical benefits. The optimum target hemoglobin, erythropoietin dosing regimen, and role of iron supplementation in patients with CHF are not known. Darbepoetin alfa is a glycosylated derivative of erythropoietin with a prolonged half-life that may allow less frequent dosing in CHF populations. Additional studies are needed to determine the safety and efficacy of long-term erythropoietic therapy in CHF patients.

Epoetin Beta

Epoetin beta (NeoRecormon) is a recombinant form of erythropoietin. It increases reticulocyte counts, haemoglobin (Hb) levels and haematocrit. Epoetin beta administered subcutaneously once weekly corrected anaemia and had equivalent efficacy to that of epoetin beta administered three times weekly in patients with haematological malignancies. Subcutaneous epoetin beta reduced transfusion requirements and increased Hb levels versus no treatment in patients with solid tumours and chemotherapy-induced anaemia in nonblind, randomised trials. Anaemia and quality of life were also improved, and blood transfusion requirements were reduced to a significantly greater extent than placebo or no treatment (with supportive blood transfusion) in patients with haematological malignancies. Most patients were receiving chemotherapy. Subcutaneous epoetin beta was well tolerated by patients with cancer; adverse events with the drug occurred with a similar incidence to those with placebo or no treatment (with supportive blood transfusion). Hypertension was relatively uncommon with epoetin beta in clinical trials. Patients with haematological malignancies and a baseline platelet count > or =100 x 10(9)/L, Hb levels of > or =9 g/dL or lower erythropoietin levels have demonstrated better responses to epoetin beta than other patients in clinical trials. However, neither baseline erythropoietin level nor the observed to predicted ratio of erythropoietin levels correlated with the response to epoetin beta in patients with solid tumours and chemotherapy-induced anaemia. A decrease of <1 g/dL or an increase in Hb with epoetin beta during the first chemotherapy cycle indicated a low transfusion need in subsequent cycles in patients with ovarian carcinoma. In general, the efficacy of epoetin beta is not limited by tumour type. Response to the drug occurred irrespective of the nature (platinum- or nonplatinum-based) or presence of chemotherapy treatment in randomised trials.

CONCLUSION

Epoetin beta has shown efficacy in the management of cancer-related anaemia in patients with haematological malignancies and of chemotherapy-induced anaemia in patients with solid tumours. Once-weekly administration provides added convenience for patients and may be cost saving, although additional research into the potential pharmacoeconomic benefits of this regimen are required. The drug is well tolerated in patients with cancer and is associated with little injection-site pain when administered subcutaneously. Epoetin beta is an important option in the prevention of chemotherapy-induced anaemia, and a valid and valuable alternative to blood transfusion therapy for the treatment of cancer-related or chemotherapy-induced anaemia.

Étude des effets directs et indirects de l’érythropoïétine dans un modèle expérimental de thrombose et de saignement chez le lapin

OBJECTIVES

To study direct and indirect effects of EPO on haemostasis.

STUDY DESIGN

Experimental, randomised.

ANIMALS

Forty-eight New Zealand rabbits.

METHOD

Animals were anaesthetised, ventilated and monitored continuously for blood pressure, heart rate, body temperature, and carotid blood flow variations and were randomised into four groups: control, EPO bolus 2400 IU kg(-1), fractionated EPO (one injection a week of 600 IU kg(-1) for 4 weeks), homologous red blood cell transfusion to reach the Ht level of the fractionated EPO group. A compression injury and a 75% stenosis of the carotid artery triggered a series of cyclic flow reductions (CFRs). CFRs were observed for a 20 min period in each group. Ear immersion bleeding time (BT) and hepato-splenic bleeding were performed at the end of the experiment. Biology was performed at the end of the thrombosis period: blood cells count, Hte, activated partial thromboplastin time, fibrinogen, arachidonic-induced platelet aggregation, EPO dosages.

RESULTS

No significant increase in thrombosis (CFRs) in the two EPO groups and in the transfused group. Increase in Hte in the fractionated EPO group versus control. Group EPO bolus: decrease in BT and hepato-splenic bleeding versus control; decrease in hepato-splenic bleeding versus fractionated EPO group, increase in platelet aggregation velocity versus control.

CONCLUSION

EPO did not increase the thrombotic risk in this rabbit model. EPO bolus decreased BT and hepato-splenic bleeding.

Plasma erythropoietin level in patients with cirrhosis and its relationship to the severity of cirrhosis and renal function

BACKGROUND AND AIM

The level of plasma erythropoietin (EPO) in patients with cirrhosis is controversial. It is known that overproduction of nitric oxide (NO) plays, in part, a role for the development of peripheral arterial vasodilatation in cirrhosis with portal hypertension. It has also been hypothesized that a possible interaction is noted between endogenous EPO and NO production. The current study was undertaken to evaluate the relationship between plasma EPO levels and the severity of liver disease, hemodynamic values, renal functions, and plasma nitrate/nitrite levels in patients with cirrhosis.

METHODS

The authors measured the biochemistry, plasma EPO and nitrate/nitrite levels in 67 patients with cirrhosis (Child-Pugh class A in 23 and Child-Pugh class B and C in 44) and compared their values with those in 34 healthy subjects. Systemic and splanchnic hemodynamic measurements and effective renal plasma flow were obtained from cirrhotic patients.

RESULTS

Plasma EPO and nitrate/nitrite levels were significantly increased in patients with cirrhosis compared with healthy subjects. Additionally, plasma EPO values were higher in cirrhotic patients with ascites or with anemia than in those without ascites or without anemia, respectively. Plasma EPO levels were positively correlated to the hepatic venous pressure gradient (HVPG) and Child-Pugh score, negatively correlated to the renal and hepatic blood flows, but were not correlated to nitrate/nitrite level and systemic vascular resistance in cirrhotic patients. Multiple regression analysis showed that HVPG and renal plasma flow were independent predictors for the elevated EPO level in cirrhotic patients.

CONCLUSIONS

Plasma EPO levels were increased in patients with cirrhosis compared with those in healthy subjects. The increase in plasma EPO levels is related to the degree of portal hypertension, the severity of cirrhosis and the renal plasma flow. In contrast, the EPO levels had no correlation to the nitrate/nitrite levels and systemic vascular resistance in patients with cirrhosis.

Chuvash-type congenital polycythemia in 4 families of Asian and Western European ancestry

The Chuvash form of polycythemia is an autosomal recessive disorder common to a large number of families in central Russia. Affected individuals have been reported to be homozygous for an Arg200Trp mutation in the von Hippel-Lindau (VHL) gene. We have screened 78 patients with erythrocytosis and found 8 of Bangladeshi and Pakistani origin to be homozygous for the Arg200Trp mutation and another of English descent to be heterozygous. Of these patients, 5 have elevated serum erythropoietin (Epo) levels, while the other 4 have Epo values in the normal range. The heterozygous patient does not fulfill the Chuvash criterion for homozygosity of the Arg200Trp mutation and consequently may harbor a further, as yet uncharacterized, mutation. This mutation has a wider geographic distribution than originally presumed and haplotype analysis suggests a common origin of the Arg200Trp mutation in the 4 families, but it still remains to be established if it has arisen independently of the Chuvash population.

The Implications of Anemia in Multiple Myeloma

Multiple myeloma (MM) is commonly associated with anemia. Several causes have been implicated, but anemia of chronic disease with inadequate erythropoietin (EPO) production related to the inflammatory cytokines appears to be of utmost importance. Interleukin-1 and tumor necrosis factor are capable of suppressing erythropoiesis. Anemia has broad implications. First, the low hemoglobin and hematocrit are associated with poor quality of life and performance and affect daily activity. Second, anemia has an impact on the cardiovascular system. Considering that most MM patients are elderly, this may be even more important. Anemia has been shown to induce or aggravate hypoxia and ischemic complications. Third, anemia has been shown to be a poor prognostic factor in MM. Traditionally, patients with symptomatic anemia were treated with red blood cell transfusions as needed. The introduction of epoetin alfa and epoetin beta into clinical practice opened new avenues to these patients. The administration of epoetins to patients with MM and anemia have been shown to be very useful. Several studies in more than 1000 patients have demonstrated a high response rate (range, 25%-85%; mean, 60%). This response is characterized by a significant increase of hemoglobin, hematocrit, and the number of red blood cells together with a reduction in the blood transfusion requirements. This is also associated with an improved quality of life. Although there is no complete agreement about the role of pretreatment serum EPO levels, many investigators believe that relatively low levels may help in predicting response, thereby limiting the number of potential candidates to receive this expensive therapy. The epoetins are safe and well tolerated with minimal toxicity; however, some concern has been recently raised regarding several dozen patients who developed pure red cell aplasia while on epoetin therapy. However, this adverse effect appears to be extremely rare. Recent data suggest that EPO has additional biologic effects, such as longer-than-expected survival in patients with MM. This observation is further supported by animal studies, demonstrating an antimyeloma effect of EPO in mice models. This effect has been shown to be immune mediated. If these exciting data are confirmed in future clinical trials, this may have significant implications on the treatment of MM.

Recombinant human erythropoietin in preoperative autologous blood donation did not influence the haemoglobin recovery after surgery

BACKGROUND

Recombinant human erythropoietin in combination with preoperative autologous blood donation is an established regime for avoiding allogenic blood transfusions. The aim of the study was to determine endogenous erythropoietin production and haemoglobin recovery after preoperative autologous blood donation and surgery, with or without recombinant human erythropoietin treatment.

METHODS

Thirty-eight patients having total hip joint replacement surgery were randomised to receive either autologous blood transfusion (control group) or autologous transfusion plus preoperative recombinant human erythropoietin treatment (EPO group). Haemoglobin, haematocrit, erythropoietin and reticulocyte concentrations were repeatedly analysed, before, during, and after surgery.

RESULTS

No significant differences were found between the groups regarding haemoglobin, haematocrit, and erythropoietin, but the reticulocyte count increased significantly more in the EPO group. There was no difference in the requirement for allogeneic blood transfusions between the groups. The baseline haemoglobin was >13 g dL-1 in all but four patients.

CONCLUSIONS

In patients with normal preoperative haemoglobin levels, recombinant human erythropoietin treatment did not improve haemoglobin levels, or reduce the need for allogenic blood transfusion. There were no differences in serum erythropoietin concentrations between the groups. We question whether recombinant human erythropoietin treatment facilitates preoperative autologous blood donation in patients with normal haemoglobin levels.

[Peri-operative use of EPO]

In moderately anaemic patients, Autologous Blood Donation is much less effective than Erythropoïetin (EPO) at constituting a pre-operative RBC reserve. Indeed, the ability to give blood is limited or even impossible for anaemic individuals. EPO lowers the risks associated with autologous and allogeneic transfusions, while improving probably the quality of life of the patients. EPO therapy is efficient, in moderate anaemic patients, to reduce allogeneic transfusion when iron supplementation is associated. All blood conservation techniques carry their own efficiency limits, constraints and risks that, in addition to institutional considerations and individual patient characteristics, are determinant to settle a blood conservation strategy. But to optimise benefit/cost/effectiveness of this technique, it is important to take into account the delay before surgery, the anticipated blood loss for the procedure that varies among institutions and the tolerable blood loss without transfusion for the patient. To reduce the cost, a strategy according to baseline haematocrit and to blood loss has to be adapted at each patient. Furthermore, when the delay between the first EPO injection and the surgical procedure is sufficient, the number of injections can be easily reduced to obtain the same Ht the day prior to surgery.