Inadequate erythropoietin response to anemia: definition and clinical relevance

Anti-anemia effects of ginsenoside Rk3 and ginsenoside Rh4 on mice with ribavirin-induced anemia

Ginsenoside Rk3 and ginsenoside Rh4 stimulate hematopoiesis and show excellent anti-anemia effectsviathe combined effects of different related cytokines.

Disease severity and erythropoiesis in chronic hepatitis C

BACKGROUND/AIMS

The erythropoiesis in hepatitis C virus infection is unclear. We aimed to evaluate the erythropoietic components in chronic hepatitis C (CHC) patients.

METHODS

The red blood cell (RBC) components, serum erythropoietin (EPO) levels, and their relationship to clinical characteristics were evaluated between 124 age-matched and sex-matched healthy controls and 248 histology-proven CHC patients.

RESULTS

Chronic hepatitis C patients had significantly higher serum levels of EPO (1.44 ± 0.36 log mIU/mL versus 1.03 ± 0.31 log mIU/mL, P < 0.0001) and lower hemoglobin (Hb) concentrations (14.6 ± 1.4 g/dL versus 15.3 ± 1.2 g/dL, P < 0.001) as compared with healthy controls. Among the CHC patients, the serum EPO level was negatively associated with the Hb concentration (β = -0.227; 95% confidence intervals [CI]: -0.09-0.027; P < 0.001) and RBC counts (β = -0.204; 95% CI: -0.245-0.061; P = 0.001) and was positively correlated with necroinflammatory activity (β = 0.201; 95% CI: 0.009-0.046; P = 0.003) and fibrosis (β = 0.143; 95% CI: 0.003-0.076; P = 0.04) of liver histopathology. For non-cirrhotic CHC patients, the severity of liver necroinflammatory activity was positively correlated with the reticulocyte and serum EPO levels (P = 0.001 and 0.008, respectively), and negatively related to the RBC counts (P = 0.03). Using stepwise multivariate linear regression analysis, the grade of necroinflammatory activity was positive (β = 0.214; 95% CI: 0.046-0.209, P = 0.002), whereas the Hb concentration was inversely (β = -0.205; 95% CI: -0.09-0.018, P = 0.004) associated with the serum EPO levels in CHC patients.

CONCLUSIONS

The disease activity in CHC patients had a negative impact on erythropoiesis with compensatory higher but blunted EPO responses.

The role of inflammation, iron, and nutritional status in cancer-related anemia: results of a large, prospective, observational study

Anemia in oncology patients is often considered a side effect of cancer therapy; however, it may occur before any antineoplastic treatment (cancer-related anemia). This study was aimed to evaluate the prevalence of cancer-related anemia in a large cohort of oncology patients and whether inflammation and malnutrition were predictive of its development and severity. The present study included 888 patients with cancer at different sites between May 2011 and January 2014. Patients were assessed at diagnosis before any cancer treatment. The prevalence of anemia according to the main clinical factors (tumor site, stage and performance status) was analyzed. In each patient markers of inflammation, iron metabolism, malnutrition and oxidative stress as well as the modified Glasgow prognostic score, a combined index of malnutrition and inflammation, were assessed and their role in predicting hemoglobin level was evaluated. The percentage of anemic patients was 63% with the lowest hemoglobin levels being found in the patients with most advanced cancer and compromised performance status. Hemoglobin concentration differed by tumor site and was lowest in patients with ovarian cancer. Hemoglobin concentration was inversely correlated with inflammatory markers, hepcidin, ferritin, erythropoietin and reactive oxygen species, and positively correlated with leptin, albumin, cholesterol and antioxidant enzymes. In multivariate analysis, stage, interleukin-6 and leptin were independent predictors of hemoglobin concentration. Furthermore, hemoglobin was inversely dependent on modified Glasgow Prognostic Score. In conclusion, cancer-related anemia is a multifactorial problem with immune, nutritional and metabolic components that affect its severity. Only a detailed assessment of the pathogenesis of cancer-related anemia may enable clinicians to provide safe and effective individualized treatment.

Elevated erythropoietin and cytokines levels are related to impaired reticulocyte maturation in thalassemic patients

Serum EPO concentration is related primarily to the rate of erythrocyte production and, under the stimulation of hypoxia, increases exponentially as hemoglobin (Hb) decreased. The level of EPO was determined in 141 subjects including 43 normal, 44 thalassemic patients and 54 thalassemic trait subjects. The EPO level was significantly higher in the thalassemic patients (54.8mU/ml in HbH disease [α thal1/α thal2;], 78.1mU/ml in HbH with Hb CS [α thal 1/CS]; 95.6mU/ml in β-thal/HbE splenectomized [BE(S)]; and 114.8mU/ml in β-thal/HbE non-splenectomized [BE(NS)]as compared with 12.0mU/ml in normal subjects. No significant differences were detected in thalassemic trait subjects. In addition, the levels of EPO in thalassemic patients is correlated significantly with the number of reticulocytes and the reticulocyte fractions especially the fraction of immature reticulocytes. Interestingly, the highest level of EPO/% retic ratio as indicated for EPO non-responder was detected in BE(NS) patients. However, the impaired reticulocytes maturation was found to be related significantly with the levels of TNF-α,IFN-γ,IL-10, and VEGF. Since, TNF-α, IFN-γ, IL-10 and VEGF are reported as the cytokines with erythropoietic inhibitory mediators, the variation of these cytokines in thalassemic environments may be associated to the anemic crisis in these patients.

Anemia of chronic disease: a unique defect of iron recycling for many different chronic diseases

Anemia of chronic disease (ACD) is frequently observed in patients with chronic diseases as a significant contributor to morbidity and mortality, which can aggravate the severity of symptoms of the underlying inflammatory status. The pathophysiology of ACD is multifactorial, including three mechanisms: shortened erythrocyte survival, impaired proliferation of erythroid progenitor cells, and abnormalities of iron metabolism. These mechanisms are "immune and inflammation"-driven, but several other factors, including chronic blood loss, hemolysis, or vitamin deficiencies, can aggravate anemia. All the abnormalities of iron metabolism observed in ACD can be explained by the effect of hepcidin upregulation. Hepcidin is a small liver peptide, that inhibits the cellular macrophage efflux of iron and intestinal iron absorption, binding to ferroportin and inducing its internalization and degradation. In ACD the synthesis of hepcidin is upregulated by increased inflammatory cytokines, causing the two main principal features: the macrophage iron sequestration and the iron-restricted erythropoiesis. ACD is the most complex anemia to treat. The recommended approach is the treatment of the underlying disease, which can lead to a major improvement or even resolution of ACD. Currently available treatments (transfusion, iron, and erythropoiesis-stimulating agents) can ameliorate anemia, but a considerable percentage of non-responders exist. On this evidence new treatment strategies might arise from the knowledge of the pathophysiology of ACD, in which hepcidin plays the central role. Prospective studies are needed to evaluate the safety and the efficacy of the new emerging treatments, which modulate hepcidin expression through different mechanisms.

Anti-erythropoietin receptor antibodies in systemic lupus erythematosus patients with anemia

Anemia is a common hematologic abnormality in systemic lupus erythematosus (SLE). An inadequate erythropoietin (EPO) response in SLE patients with anemia has been described that may be due to the presence of antibodies to EPO in SLE patients. However, whether anemia in patients with SLE is related to antibodies to EPO receptor (EPOR) has not yet been investigated. We enlisted 169 consecutive patients with SLE and 45 normal individuals to investigate the existence and importance of circulating autoantibodies to EPOR in sera from patients with SLE. In all patients with SLE, the disease activity was evaluated by using the SLE disease activity index SLEDAI. Anti-EPOR antibodies were detected by using an enzyme-linked immunosorbent assay (ELISA). A higher frequency of anti-EPOR antibodies was observed in SLE patients than in healthy controls (18.3% vs 2.2%, p = 0.007). Moreover, anti-EPOR antibodies were detected in 22 of 69 (31.9%) SLE patients with anemia and in only nine of 100 (9.0%, p < 0.001) in those without. Furthermore, the patients with anti-EPOR antibodies exhibited more severe anemia and often presented as microcytic anemia (p = 0.001). Finally, anti-EPOR antibodies seemed more likely to occur in patients with rash (p = 0.008), lower levels of C(3) component (p = 0.01), higher titer of anti-dsDNA antibodies (p < 0.001) and higher disease activity scores (p = 0.024). The results of this study suggest that anti-EPOR antibodies might play a vital role in SLE patients developing anemia because of the higher incidence of antibodies to EPOR found in SLE patients with anemia. Thus, there might be clinical value in detecting anti-EPOR antibodies in SLE patients with anemia. Therefore, the pathologic role of the antibodies in inducing anemia needs to be established in future studies.

Prognostic significance of erythropoietin in pancreatic adenocarcinoma

BACKGROUND

Erythropoietin (Epo) administration has been reported to have tumor-promoting effects in anemic cancer patients. We investigated the prognostic impact of endogenous Epo in patients with pancreatic ductal adenocarcinoma (PDAC).

METHODOLOGY

The clinico-pathological relevance of hemoglobin (Hb, n = 150), serum Epo (sEpo, n = 87) and tissue expression of Epo/Epo receptor (EpoR, n = 104) was analyzed in patients with PDAC. Epo/EpoR expression, signaling, growth, invasion and chemoresistance were studied in Epo-exposed PDAC cell lines.

RESULTS

Compared to donors, median preoperative Hb levels were reduced by 15% in both chronic pancreatitis (CP, p<0.05) and PDAC (p<0.001), reaching anemic grade in one third of patients. While inversely correlating to Hb (r = -0.46), 95% of sEPO values lay within the normal range. The individual levels of compensation were adequate in CP (observed to predicted ratio, O/P = 0.99) but not in PDAC (O/P = 0.85). Strikingly, lower sEPO values yielding inadequate Epo responses were prominent in non-metastatic M0-patients, whereas these parameters were restored in metastatic M1-group (8 vs. 13 mU/mL; O/P = 0.82 vs. 0.96; p<0.01)--although Hb levels and the prevalence of anemia were comparable. Higher sEpo values (upper quartile ≥ 16 mU/ml) were not significantly different in M0 (20%) and M1 (30%) groups, but were an independent prognostic factor for shorter survival (HR 2.20, 10 vs. 17 months, p<0.05). The pattern of Epo expression in pancreas and liver suggested ectopic release of Epo by capillaries/vasa vasorum and hepatocytes, regulated by but not emanating from tumor cells. Epo could initiate PI3K/Akt signaling via EpoR in PDAC cells but failed to alter their functions, probably due to co-expression of the soluble EpoR isoform, known to antagonize Epo.

CONCLUSION/SIGNIFICANCE

Higher sEPO levels counteract anemia but worsen outcome in PDAC patients. Further trials are required to clarify how overcoming a sEPO threshold ≥16 mU/ml by endogenous or exogenous means may predispose to or promote metastatic progression.

Hepcidin expression in anemia of chronic disease and concomitant iron-deficiency anemia

Hepcidin is a key hormone governing mammalian iron homeostasis and may be directly or indirectly involved in the development of most iron deficiency/overload and inflammation-induced anemia. The objective of this study was to investigate the expression of hepcidin in anemia of chronic disease. To characterize serum hepcidin, iron and inflammatory indicators associated with anemia of chronic disease (ACD), we studied ACD, ACD concomitant iron-deficiency anemia (ACD/IDA), pure IDA and acute inflammation (AcI) patients and analyzed the associations between hepcidin levels and inflammation parameters in various types of anemia. Serum hepcidin levels in patient groups were statistically different, from high to low: ACD, AcI > ACD/IDA > the control > IDA. Serum ferritin levels were significantly increased in ACD and AcI patients but were decreased significantly in ACD/IDA and IDA. Elevated serum EPO concentrations were found in ACD, ACD/IDA and IDA patients but not in AcI patients and the controls. A positive correlation between hepcidin and IL-6 levels only existed in ACD/IDA, AcI and the control groups. A positive correlation between hepcidin and ferritin was marked in the control group, while a negative correlation between hepcidin and ferritin was noted in IDA. The significant negative correlation between hepcidin expression and reticulocyte count was marked in both ACD/IDA and IDA groups. All of these data demonstrated that hepcidin might play role in pathogenesis of ACD, ACD/IDA and IDA, and it could be a potential marker for detection and differentiation of these anemias.

Circulating antibodies to endogenous erythropoietin and risk for HIV-1-related anemia

OBJECTIVES

In a previous retrospective study we have shown that circulating antibodies to endogenous erythropoietin (anti-EPO) are associated with HIV-1-related anemia. The present longitudinal cohort study was conducted to examine the effect of anti-EPO on the risk of developing anemia over time.

METHODS

The study population consisted of 113 HIV-1 seropositive patients, who were screened for the presence of anti-EPO, with a mean+/-SD follow up of 105+/-40 months, for a total of 2190 visits. Anti-EPO were detected with an ELISA assay.

RESULTS

Anti-EPO were detected in 41% (46/113) at enrollment and 29% (320/1094) for all visits, and were associated with higher EPO levels for all visits (45.7+/-60.4 vs. 31.8+/-31.7 IU/ml, p<0.001). After adjusting for other significant confounders, anti-EPO has been associated with increased risk of anemia both at enrollment (odds ratio [OR], 5.07; 95% confidence interval [CI], 1.25-20.49) as well as for all visits ([OR], 2.15; 95% [CI]: 1.29-3.56). During follow up, a decline in prevalence of both anti-EPO and anemia was observed as the percentage of patients receiving HAART was increasing.

CONCLUSIONS

Anti-EPO are an independent risk factor for anemia in HIV-1-infected patients. HAART seems to reduce both anti-EPO and anemia prevalence.

Quantitative analysis of mechanisms that govern red blood cell age structure and dynamics during anaemia

Mathematical modelling has proven an important tool in elucidating and quantifying mechanisms that govern the age structure and population dynamics of red blood cells (RBCs). Here we synthesise ideas from previous experimental data and the mathematical modelling literature with new data in order to test hypotheses and generate new predictions about these mechanisms. The result is a set of competing hypotheses about three intrinsic mechanisms: the feedback from circulating RBC concentration to production rate of immature RBCs (reticulocytes) in bone marrow, the release of reticulocytes from bone marrow into the circulation, and their subsequent ageing and clearance. In addition we examine two mechanisms specific to our experimental system: the effect of phenylhydrazine (PHZ) and blood sampling on RBC dynamics. We performed a set of experiments to quantify the dynamics of reticulocyte proportion, RBC concentration, and erythropoietin concentration in PHZ-induced anaemic mice. By quantifying experimental error we are able to fit and assess each hypothesis against our data and recover parameter estimates using Markov chain Monte Carlo based Bayesian inference. We find that, under normal conditions, about 3% of reticulocytes are released early from bone marrow and upon maturation all cells are released immediately. In the circulation, RBCs undergo random clearance but have a maximum lifespan of about 50 days. Under anaemic conditions reticulocyte production rate is linearly correlated with the difference between normal and anaemic RBC concentrations, and their release rate is exponentially correlated with the same. PHZ appears to age rather than kill RBCs, and younger RBCs are affected more than older RBCs. Blood sampling caused short aperiodic spikes in the proportion of reticulocytes which appear to have a different developmental pathway than normal reticulocytes. We also provide evidence of large diurnal oscillations in serum erythropoietin levels during anaemia.

Antiviral therapy in hepatitis C virus cirrhotic patients in compensated and decompensated condition

The main goals of treating cirrhotic patients with antiviral therapy are to attain sustained viral clearance (SVR), halt disease progression, and prevent re-infection of the liver graft. However, while the medical need is great, the use of interferon and ribavirin might expose these patients to severe treated-related side effects as a large proportion of them have pre-existing hematological cytopenias. We have reviewed potential benefits and risks associated with antiviral drugs in patients with liver cirrhosis, due to hepatitis C virus (HCV) infection. In cases presenting with bridging fibrosis or cirrhosis, current regimens of antiviral therapy have attained a 44%-48% rate of SVR. In cirrhotic patients with portal hypertension, the SVR rate was 22% overall, 12.5% in patients with genotype 1, and 66.7% in those with genotypes 2 and 3 following therapy with low doses of either Peg-IFN alpha-2b and of ribavirin. In patients with decompensated cirrhosis, full dosages of Peg-IFN alpha-2b and of ribavirin produced a SVR rate of 35% overall, 16% in patients with genotype 1 and 4, and 59% in those with genotype 2 and 3. Use of hematological cytokines will either ensure full course of treatment to be accomplished with and prevent development of treatment-associated side effects. Major benefits after HCV eradication were partial recovery of liver metabolic activity, prevention of hepatitis C recurrence after transplantation, and removal of some patients from the waiting list for liver transplant. Several observations highlighted that therapy is inadvisable for individuals with poor hepatic reserve (Child-Pugh-Turcotte score ≥ 10). Although SVR rates are low in decompensated cirrhotics due to hepatitis C, these patients have the most to gain as successful antiviral therapy is potentially lifesaving.

Stimulating erythropoiesis in inflammatory bowel disease associated anemia

Anemia is a frequent complication in patients with inflammatory bowel disease (IBD), and is associated with decreased quality of life and increased rate of hospitalization. The primary therapeutic targets of IBD-associated anemia are iron deficiency and anemia of chronic disease. An important prognostic parameter of the success or failure of therapy is the outcome of the underlying disease. Iron deficiency should be appropriately managed with iron supplementation. However, the use of oral iron therapy is limited by several problems, the most important being gastrointestinal side effects leading occasionally to disease relapse and poor iron absorption. Intravenous iron preparations are more reliable, with iron sucrose demonstrating the best efficacy and tolerability. Treatment with erythropoietin or darbepoetin has been proven to be effective in patients with anemia, who fail to respond to intravenous iron. Patients with ongoing inflammation have anemia of chronic disease and may require combination therapy comprising of intravenous iron sucrose and erythropoietin. After initiating treatment, careful monitoring of hemoglobin levels and iron parameters is needed in order to avoid recurrence of anemia. In conclusion, anemia in the setting of IBD should be aggressively diagnosed, investigated, and treated. Future studies should define the optimal dose and schedule of intravenous iron supplementation and appropriate erythropoietin therapy in these patients.

Erythropoietin and iron-restricted erythropoiesis

Twenty five years ago, Finch summarized knowledge gained primarily from studies of normal individuals, patients with hereditary hemolytic anemias, and patients with hemochromatosis [1]. Under conditions of basal erythropoiesis in normal subjects, plasma iron turnover (as an index of marrow erythropoietic response) is little affected, whether transferrin saturation ranges from very low to very high levels. In contrast, the erythropoietic response in individuals with congenital hemolytic anemia, in whom erythropoiesis is chronically raised up to sixfold over basal levels [2], is affected (and limited) by serum iron levels and by transferrin saturation [3]. Patients with hemochromatosis who underwent serial phlebotomy were observed to mount erythropoietic responses of up to eightfold over basal rates, attributed to the maintenance of very high serum iron and transferrin saturation levels in these patients [4], whereas normal individuals were shown to have difficulty providing sufficient iron to support rates of erythropoiesis greater than three times basal rates [5]. These observations led Finch to identify a "relative iron deficiency" state, also known as "functional iron deficiency," which he defined as circumstances in which increased erythron iron requirements exceed the available supply of iron [6]. In another clinical setting, patients undergoing autologous blood donation represent a model for perisurgical blood loss and the erythropoietic response. Insights gained over the last 20 years regarding the relationship between erythropoietin, iron, and erythropoiesis, along with implications for clinical management, will be reviewed.

Natural history of anemia associated with interferon/ribavirin therapy for patients with HIV/HCV coinfection

The natural history of anemia related to interferon/ribavirin (IFN/RBV) treatment in patients with human immunodeficiency virus/hepatitis C virus (HIV/HCV) coinfection is not completely understood. The current 8-week, multicenter, observational study characterized anemia over the course of HCV treatment in patients with HIV/HCV coinfection. Eligible HIV/HCV coinfected patients were receiving care in community-based and academic institutions and were on stable antiretroviral therapy and initiating IFN/RBV therapy. Hb, sEPO, reticulocytes, transfusions, laboratory values (e.g., total bilirubin), and IFN and RBV dosages were monitored weekly. Ninety-one patients were analyzed (mean age, 46 years; 71% on HAART) and 53 patients completed the study. Mean Hb decreased significantly (5.0 g/dl) within 1 week of initiating IFN/RBV therapy (p = 0.0002); Hb nadir occurred at a median of 37 days. Maximum Hb decreases of > or =2.0 g/dl occurred in 56 (62%) patients and > or =3.0 g/dl occurred in 45 (49%) patients. Reticulocyte count increased within the first 2 weeks and sEPO peaked at week 3. Mean increase from baseline to week 2 in reticulocyte count and sEPO, respectively, was 1.3% (n = 74) and 45.0 mIU/ml (n = 80) (p < 0.0001 for each parameter), and from baseline to week 8 was 0.9% (n = 48) and 41.0 mIU/ml (n = 52) (p < or = 0.0001 for each parameter). Adverse events (AEs) were the most common reason for study discontinuation (66% of discontinuing patients). Among the 25 patients who discontinued due to AEs, 84% discontinued due to anemia (n = 21). Significant decreases in Hb were observed in HIV/HCV-coinfected patients within 1 week of initiating IFN/RBV therapy. sEPO and reticulocyte increases were blunted in response to anemia; Hb levels did not return to baseline values and anemia was a frequent reason for discontinuing the study.

Evidence for downregulation of erythropoietin receptor in bone marrow erythroid cells of patients with chronic idiopathic neutropenia

OBJECTIVE

The aim of this study is to probe the mechanisms underlying anemia in patients with chronic idiopathic neutropenia (CIN) by evaluating parameters of bone marrow (BM) erythropoiesis.

PATIENTS AND METHODS

Ten CIN patients fulfilling the criteria of anemia of chronic disease, 27 nonanemic CIN patients, and 30 healthy volunteers were enrolled in the study. Reserves and survival characteristics of BM erythroid cells were evaluated using flow cytometry and clonogenic assays. Serum erythropoietin (EPO) was measured with ELISA. Expression of EPO receptors (EPORs) on BM erythroid cells was evaluated by flow cytometry and reverse-transcription polymerase chain reaction.

RESULTS

CIN patients display defective erythropoiesis in addition to previously reported impaired granulopoiesis. Patients have low number of CD34(+)/CD71(+) progenitor and CD36(-)/ Glycophorin A(+) (GlycoA(+)) precursor BM cells, and increased proportion of apoptotic cells within the CD34(+)/CD71(+) and CD36(+)/GlycoA(+) compartments. Burst-forming units erythroid (BFU-Es) in BM mononuclear or purified CD34(+) cells were significantly reduced in the patients. Patient BFU-Es increased significantly following in vitro treatment with tumor necrosis factor-alpha (TNF-alpha) and/or interferon gamma (IFN-gamma)-neutralizing antibodies. Local TNF-alpha and IFN-gamma production was higher in anemic than in nonanemic patients. EPO production was appropriate in the patients, but EPOR expression was significantly reduced in patient GlycoA(+) cells, especially in anemic patients.

CONCLUSION

Impaired BM erythropoiesis in CIN patients is probably the result of increased local production of TNF-alpha and IFN-gamma that induce apoptosis, cell growth inhibition, and downregulation of EPOR expression on erythroid cells. We suggest that anemia in CIN patients displays overlapping pathophysiologic features with anemia of chronic disease.

Increased iron absorption during autologous blood donation supported by recombinant human erythropoietin therapy

BACKGROUND

Recombinant human erythropoietin (rHuEPO) therapy improves the success of autologous blood (AB) donation programs before elective surgery. The aim of this study was to evaluate iron absorption during an AB donation program with or without rHuEPO.

STUDY DESIGN AND METHODS

Thirty-two patients were randomly assigned among placebo (Group 1) or 300 (Group 2) or 600 UI per kg rHuEPO (Group 3) on the first, second, and third donation visits. All patients also received daily oral iron (200 mg Fe(+)).

RESULTS

The number of units collected in Group 3 was higher than in Group 1 (4.6 +/- 0.5 vs. 3.6 +/- 0.8 units; p < 0.01). Red blood cell (RBC) production increased in a rHuEPO dose-dependent manner. With rHuEPO, the RBC volume collected per unit presented a lower decrease with number of donated units than with placebo and was similar to that of homologous blood units. Storage iron did not influence the number of units collected, whereas circulating mobilizable iron was the limiting factor. Oral iron absorption increased in a rHuEPO dose-dependent manner (12-fold with 600 UI/kg rHuEPO) and was proportional to erythropoietic activity.

CONCLUSION

rHuEPO does not only improve the number of AB units collected but also their quality. Storage iron cannot meet marrow iron requirements, but rHuEPO strongly increased oral iron absorption in a dose-dependent fashion through stimulation of erythropoietic activity.

Vitamin A supplementation in children with poor vitamin A and iron status increases erythropoietin and hemoglobin concentrations without changing total body iron

BACKGROUND

Vitamin A deficiency impairs iron metabolism; vitamin A supplementation of vitamin A-deficient populations may reduce anemia. The mechanism of these effects is unclear. In vitro and in animal models, vitamin A treatment increases the production of erythropoietin (EPO), a stimulant of erythropoiesis.

OBJECTIVE

We measured the effect of vitamin A supplementation on hemoglobin, iron status, and circulating EPO concentrations in children with poor iron and vitamin A status.

DESIGN

In a double-blind, randomized trial, Moroccan schoolchildren (n = 81) were given either vitamin A (200,000 IU) or placebo at baseline and at 5 mo. At baseline, 5 mo, and 10 mo, hemoglobin, indicators of iron and vitamin A status, and EPO were measured.

RESULTS

At baseline, 54% of children were anemic; 77% had low vitamin A status. In the vitamin A group at 10 mo, serum retinol improved significantly compared with the control group (P < 0.02). Vitamin A treatment increased mean hemoglobin by 7 g/L (P < 0.02) and reduced the prevalence of anemia from 54% to 38% (P < 0.01). Vitamin A treatment increased mean corpuscular volume (P < 0.001) and decreased serum transferrin receptor (P < 0.001), indicating improved iron-deficient erythropoiesis. Vitamin A decreased serum ferritin (P < 0.02), suggesting mobilization of hepatic iron stores. Calculated from the ratio of transferrin receptor to serum ferritin, overall body iron stores remained unchanged. In the vitamin A group at 10 mo, we observed an increase in EPO (P < 0.05) and a decrease in the slope of the regression line of log10(EPO) on hemoglobin (P < 0.01).

CONCLUSION

In children deficient in vitamin A and iron, vitamin A supplementation mobilizes iron from existing stores to support increased erythropoiesis, an effect likely mediated by increases in circulating EPO.

Anaemia in systemic lupus erythematosus: from pathophysiology to clinical assessment

Haematological abnormalities are common in systemic lupus erythematosus. Anaemia is found in about 50% of patients, with anaemia of chronic disease being the most common form. Impaired erythropoietin response and presence of antibodies against erythropoietin may contribute to the pathogenesis of this type of anaemia. Patients with autoimmune haemolytic anaemia usually belong to a distinct category, which is associated with anticardiolipin antibodies, thrombosis, thrombocytopenia, and renal disease, often in the context of secondary antiphospholipid syndrome. Autoantibodies, T lymphocytes, and deregulation of the cytokine network can affect bone marrow erythropoiesis, leading to anaemia.

High Serum Erythropoietin Level Is Associated With Smaller Infarct Size in Patients With Acute Myocardial Infarction Who Undergo Successful Primary Percutaneous Coronary Intervention

OBJECTIVES

We investigated whether a higher serum erythropoietin (EPO) level in patients with acute myocardial infarction (MI) subjected to successful primary percutaneous coronary intervention (PCI) can predict a smaller infarct size determined by creatine kinase (CK) release.

BACKGROUND

Erythropoietin has been shown to protect cardiomyocytes from ischemia-reperfusion injury in rodents.

METHODS

We prospectively studied 101 patients with first MI who received successful primary PCI within 12 h from the onset of MI. Blood samples were collected to examine the serum EPO level after the primary PCI and within 24 h from the onset of MI.

RESULTS

The peak CK level and cumulative CK release were significantly lower in the above-median EPO group than in the below-median EPO group. Thrombolysis In Myocardial Infarction (TIMI) grades and collateral grades before PCI, infarct-related coronary arteries, time to the successful reperfusion from the onset of MI, and serum creatinine levels were similar in the two EPO groups. A stepwise multiple regression analysis revealed that the absolute serum EPO level (mU/ml) as well as TIMI grades after PCI and preinfarction angina was an independent predictor for the cumulative CK release.

CONCLUSIONS

These data suggest that a high endogenous EPO level can predict a smaller infarct size in patients with acute MI subjected to successful primary PCI. This might be attributed to the potentially protective effect of endogenous EPO against ischemia-reperfusion injury in humans.

Erythropoietic response to anemia in chronic hepatitis C patients receiving combination pegylated interferon/ribavirin

OBJECTIVES

In hepatitis C virus (HCV)-infected patients receiving pegylated interferon (PEG-IFN)/ribavirin (RBV) combination therapy, anemia is a well-known side effect. The purpose of this study was to describe the time course and extent of hemoglobin (Hb) changes and the erythropoietic response to PEG-IFN/RBV-induced anemia.

METHODS

In this multicenter, observational, 8-wk study, laboratory parameters were measured weekly for 8 wk or until early withdrawal. Primary endpoints included changes in Hb and serum erythropoietin (sEPO) from baseline to week 8; other measures were changes in reticulocytes and RBV dose. The predictive value of baseline factors for maximum Hb decline was assessed.

RESULTS

In the 97 evaluable patients, mean Hb decreased from 14.4 +/- 1.4 g/dl (baseline) to 11.9 +/- 1.3 g/dl (week 8). Twenty-one percent of patients withdrew before week 8. The estimated erythropoietic response was lower than that seen in two historic control populations of iron deficiency anemia patients. Mean RBV dose decreased from 986 +/- 190 mg/day (baseline) to 913 +/- 228 mg/day (week 8). Fifty-seven out of 77 (74%) patients who completed the study maintained their initial prescribed RBV dose. Patients maintained on the initial dose of RBV who had a higher baseline Hb and viral load showed a trend toward larger Hb declines. Platelets and white blood cells (WBCs) also declined during the study.

CONCLUSIONS

HCV-infected patients receiving PEG-IFN/RBV therapy have reductions in Hb, platelets, and WBCs, possibly due to bone marrow suppression. They also have diminished endogenous sEPO production for their degree of anemia.

Indications et limites de l'utilisation d'érythropoïétine recombinée en réanimation

OBJECTIVE

To analyze the data from the literature on erythropoietin and the future indications of recombinant human erythropoietin in intensive care unit (ICU) patients.

DATA SOURCE

References were obtained from computerized bibliographic research (Pubmed) from 1986 to 2003, except for some physiologic data.

DATA SELECTION

Original articles, reviews, and letters to editor in French and English were selected and analyzed.

DATA SYNTHESIS

An anemia is often observed in patients hospitalized in ICU. This anemia may be due to many reasons. The management of anemia consists on the treatment of the underlying disease associated with the transfusion of red blood cells. Recent studies provided evidence of an association between transfusions and mortality in ICU patients. The anemia of ICU patients is compared to the anemia of chronic diseases, which is characterized by a blunted erythropoietin. A treatment with rHuEPO may be a future therapeutic of the anemia in such patients. A multicentric study shows the efficacy of recombinant erythropoietin therapy on a decrease in the use of red blood cell, and another clinical trial highlights a decrease of the proportion of ICU patients receiving red blood cell. Recombinant erythropoietin could be an alternative to transfusion in certain conditions and certain ICU patients. Further studies are needed to determine the consequences on mortality rate and to clarify the place of this therapy in ICU patients.

Anemia in cancer: therapeutic implications and interventions

Significant progress has been made in the prevention and management of many symptoms associated with cancer and its therapy. Anemia in cancer may be secondary to blood loss, displacement of normal bone marrow cells by malignant cells, myelotoxic therapy, or the tumor itself. Practitioners may not always adequately assess anemia unless it represents a source of significant symptoms or patient distress. Risk factors include platinum-based treatment regimens, specific tumor types, and low baseline hemoglobin levels. Anemia may have an impact on patient performance status, quality of life, clinical symptoms, and possibly therapeutic efficacy and survival. Treatment interventions, directed toward the underlying etiology of the anemia, involve iron supplementation, blood transfusion, and administration of recombinant human erythropoietin. Future advances may include new tools to assess physical or functional symptoms and predict therapeutic response more accurately, and more cost-effective, convenient agents to prevent or treat anemia in cancer. Novel approaches that may add to the armamentarium of strategies designed to address anemia in patients with cancer currently are being developed.

Normal Erythropoietin Response in Chronic Hepatitis C Patients with Ribavirin-Induced Anaemia

Background

Ribavirin administration for chronic hepatitis C is associated with the development of haemolytic anaemia, which affects treatment efficacy and tolerability. In a pilot study, the exogenous administration of erythropoietin has been shown to be beneficial, reducing the rate of ribavirin dose reduction. How ribavirin administration affects normal erythropoietin production has not been determined.

Aim

To investigate the endogenous erythropoietin response in hepatitis C patients with ribavirin-induced anaemia.

Methods

Serum erythropoietin was measured before and during interferon–ribavirin treatment in 18 HCV-positive subjects. Mathematical analysis and modelling were applied to compare the degree of erythropoietin increase in HCV-positive and in otherwise healthy anaemic patients, and estimate the endogenous excess erythropoietin production in response to ribavirin-induced anaemia.

Results

Erythropoietin concentration increased significantly in response to anaemia caused by ribavirin. The physiological erythropoietin response to the ribavirin-induced anaemia was as adequate in HCV-positive subjects as it is in anaemic subjects without liver disease. The recommended exogenous erythropoietin dose appears three-times greater than the endogenous erythropoietin boost.

Conclusion

Chronic liver damage by HCV does not affect the physiological erythropoietin response to ribavirin-induced anaemia. While the rationale for erythropoietin treatment of ribavirin-induced anaemia is not straightforward, the currently recommended dosing regimen should be reassessed.

Malarial anemia leads to adequately increased erythropoiesis in asymptomatic Kenyan children

Malarial anemia is associated with a shift in iron distribution from functional to storage compartments. This suggests a relative deficit in erythropoietin production or action similar to that observed in other infections. Our study in Kenyan children with asymptomatic malaria aimed at investigating whether malaria causes increased erythropoiesis, and whether the erythropoietic response appeared appropriate for the degree of resulting anemia. Longitudinal and baseline data were used from a trial with a 2 x 2 factorial design, in which 328 anemic Kenyan children were randomly assigned to receive either iron or placebo, and sulfadoxine-pyrimethamine or placebo. Erythropoiesis was evaluated by serum concentrations of erythropoietin and soluble transferrin receptor. Prospectively collected data showed that malarial infection resulted in decreased hemoglobin concentrations, and increased serum concentrations of erythropoietin and transferrin receptor. Conversely, disappearance of malarial antigenemia resulted in increased hemoglobin concentrations, and decreased concentrations of these serum indicators. Additionally, our baseline data showed that current or recent malarial infection is associated with increased serum concentrations of erythropoietin and transferrin receptor, and that these were as high as or perhaps even higher than values of children without malarial infection and without inflammation. Our findings indicate that in asymptomatic malaria, the erythropoietic response is adequate for the degree of anemia, and that inflammation probably plays no or only a minor role in the pathogenesis of the resulting anemia. Further research is needed to demonstrate the role of deficient erythropoietin production or action in the pathogenesis of the anemia of symptomatic malaria.

Anemia of chronic disease in rheumatoid arthritis is associated with increased apoptosis of bone marrow erythroid cells: improvement following anti-tumor necrosis factor-alpha antibody therapy

Circumstantial evidence has implicated tumor necrosis factor alpha (TNF-alpha) in the pathogenesis of anemia of chronic disease (ACD) in rheumatoid arthritis (RA). We investigated the role of TNF-alpha in erythropoiesis of patients with active RA (n = 40) and the effect of anti-TNF-alpha antibody administration (cA2). Patients with RA had lower numbers of CD34+/CD71+ and CD36-/glycophorin A+ (glycoA+) bone marrow (BM) cells and increased proportions of apoptotic cells within the CD34+/CD71+ and CD36+/glycoA+ cell compartments, compared to healthy controls (n = 24). Erythroid burst-forming units (BFU-Es) obtained by BM mononuclear or purified CD34+ cells were significantly lower in RA patients compared to controls. These abnormalities were more pronounced among patients with ACD. Increased TNF-alpha levels in patient long-term BM culture supernatants inversely correlated with BFU-Es and hemoglobin levels and positively with the percentage of apoptotic CD34+/CD71+ and CD36+/glycoA+ cells. Following cA2 therapy, a normalization was documented in the number of CD34+/CD71+ and CD36-/glycoA+ cells, the number of BFU-Es, and the proportion of apoptotic CD34+/CD71+ and CD36+/glycoA+ cells, which was associated with a significant increase in hemoglobin levels compared to baseline. Recovery from anemia was more prominent in patients with ACD. The exogenous addition of an anti-TNF-alpha antibody in the cultures increased BFU-E number in patients prior to cA2 treatment but not after treatment, further substantiating the inhibitory role of TNF-alpha on patients' erythropoiesis. We conclude that TNF-alpha-mediated apoptotic depletion of BM erythroid cells may account for ACD in RA and that cA2 administration may ameliorate ACD in these patients by down-regulating the apoptotic mechanisms involved in erythropoiesis.

Biology of erythropoietin

Hypoxia induces tissue-specific gene products such as erythropoietin (EPO) and vascular endothelial growth factor (VEGF), which improve the peripheral O2 supply, and glucose transporters and glycolytic enzymes, which adapt cells to reduced O2 availability. EPO has been the fountainhead in research on pO2-dependent synthesis of proteins. The EPO gene enhancer (like the flanking DNA-elements of several other pO2-controlled genes) contains a consensus sequence (CGTG) that binds the trans-acting dimeric hypoxia-inducible factor 1 (HIF-1alpha/beta). The alpha-subunit of HIF-1 is rapidly degraded by the proteasome under normoxic conditions, but it is stabilized on occurrence of hypoxia. HIF-1 DNA-binding is also increased by insulin, and by interleukin-1 and tumor necrosis factor. Thus, in some aspects there is synergy in the cellular responses to hypoxia, glucose deficiency and inflammation. In viewing clinical medicine recombinant human EPO (rHu-EPO) has become the mainstay of treatment for renal anemia. Endogenous EPO and rHu-EPO are similar except for minor differences in the pattern of their 4 carbohydrate chains. RHu-EPO is also administered to patients suffering from non-renal anemias, such as in autoimmune diseases or malignancies. The correction of anemia in patients with solid tumors is not merely considered a palliative intervention. Hypoxia promotes tumor growth. However, the benefits of the administration of rHu-EPO to tumor patients with respect to its positive effects on tumor oxygenation, tumor growth inhibition and support of chemo- and radiotherapy is still debatable ground.

Iron deficiency anemia is highly prevalent among human immunodeficiency virus-infected and uninfected infants in Uganda

Although anemia is a common finding among human immunodeficiency (HIV)-infected infants in sub-Saharan Africa, the factors contributing to the pathogenesis of anemia have not been well characterized. We sought to characterize the relative contribution of iron deficiency and chronic disease to the anemia among infants. Hemoglobin, ferritin, erythropoietin, tumor necrosis factor-alpha (TNF-alpha), neopterin, CD4(+) lymphocyte count and plasma HIV load were measured in 165 HIV-infected and 39 uninfected 9-mo-old infants seen in an outpatient pediatric clinic in Kampala, Uganda. Among HIV-infected and uninfected infants, the prevalence of anemia (hemoglobin < 110 g/L) was 90.9 and 76.9%, respectively (P = 0.015), and the prevalence of iron deficiency anemia (hemoglobin < 110 g/L and ferritin < 12 microg/L) was 44.3 and 45.4%, respectively (P = 0.92). The relatively higher prevalence of anemia among HIV-infected infants was attributed to the anemia of chronic disease. Among infants with and without iron deficiency, the fitted regression line was log(10) plasma erythropoietin = 2.86 - 0.016.hemoglobin, and log(10) plasma erythropoietin = 4.11 - 0.028.hemoglobin, respectively, with a difference in the slope of the regression lines between log(10) erythropoietin and hemoglobin among infants with and without iron deficiency (P = 0.049). Infants in Uganda have an extremely high prevalence of anemia, and nearly half of the anemia is due to iron deficiency. The erythropoietin response to anemia appears to be upregulated among infants with iron deficiency.

Anemia and interleukin-10, tumor necrosis factor alpha, and erythropoietin levels among children with acute, uncomplicated Plasmodium falciparum malaria

Anemia is an important complication of malaria, and its pathogenesis is not well understood. To gain insight into potential age-related relationships between tumor necrosis factor alpha (TNF-alpha), interleukin 10 (IL-10), erythropoietin, and anemia during acute malaria, 273 children of ages 12 to 120 months presenting with acute, uncomplicated malaria in Kampala, Uganda, were monitored at enrollment and 3 and 7 days later. Younger children had higher geometric mean erythropoietin, TNF-alpha, and alpha(1)-acid glycoprotein (AGP) concentrations than older children. Univariate regression analysis revealed that age, log(10) erythropoietin levels, IL-10/TNF-alpha ratio, and AGP levels were each significantly associated with hemoglobin levels at baseline. Hemoglobin concentrations were inversely correlated with the log(10) erythropoietin level at all three visits. For the older age groups, higher levels of TNF-alpha were significantly associated with higher IL-10 levels at all three visits, but this relationship was significant only at baseline for younger children. These data suggest that younger children do not maintain IL-10 production in response to the inflammatory process, and this mechanism may contribute to the more severe anemia found in younger children. Acute malaria is an illness whose incidence and severity are largely age dependent. Further studies are needed to understand the relationships between age-related immune responses to malaria and their role in the pathogenesis of malarial anemia.

Impact of vitamin A supplementation on anaemia and plasma erythropoietin concentrations in pregnant women: a controlled clinical trial

INTRODUCTION

Although studies suggest that vitamin A or its metabolites influence the synthesis of erythropoietin in vitro and in animal models, it is unclear whether vitamin A supplementation increases plasma erythropoietin concentrations in humans.

OBJECTIVE

To determine whether daily vitamin A supplementation increases plasma erythropoietin concentrations in pregnant women with a high prevalence of anaemia.

METHODS

A randomized, double-blind, controlled clinical trial was conducted to examine the effect of daily vitamin A (3000 microg retinol equivalent), iron (30 mg), and folate (400 microg) versus iron (30 mg) and folate (400 microg) (control) on haemoglobin and plasma erythropoietin concentrations in 203 pregnant women in Malawi, Africa.

RESULTS

Mean gestational age at enrollment was 23 wk, at which time 50% of the women were anaemic (haemoglobin <110 g/L). Mean (+/-SEM) change in haemoglobin from enrollment to 38 wk was 4.7+/-1.6 g/L (p=0.003) and 7.3+/-2.3 g/L (p=0.003) in the vitamin A and control groups, respectively. Mean change in plasma erythropoietin concentrations from enrollment to 38 wk was 2.39+/-5.00 (p=0.63) and -2.87+/-3.92 IU/L (p=0.46) in the vitamin A and controls groups, respectively. There were no significant differences between vitamin A and control groups in the slope of the regression line between log10 erythropoietin and haemoglobin at enrollment or 38 wk, and between enrollment and follow-up within either group.

CONCLUSIONS

Vitamin A supplementation does not appear to increase haemoglobin and plasma erythropoietin concentrations among pregnant women with a high prevalence of anaemia in Malawi.

Recombinant human erythropoietin in the treatment of head and neck tumour anaemia

At the time of first diagnosis, patients with squamous cell carcinoma in the head and neck are often in the advanced stage of their disease, therefore surgery is not a viable option for treatment. These patients also present frequently a high grade of anaemia as a result of either the malignant process itself or of the following therapy. The incidence of anaemia and the need for transfusion depends on several factors, such as the type and intensity of radiotherapy and radiochemotherapy. Multimode therapeutic concepts such as radio-chemotherapy are being applied with increasing frequency, resulting in an ever increasing need for transfusion with great effects on the patient's quality of life. Even more important to tumour patients is the role of the haemaglobin (Hb) value as a prognostic factor for survival and/or local tumour control. A large number of studies show that recombinant human erythropoietin (r-HuEPO) is effective in the treatment of tumour-induced anaemia and prevention and correction of chemotherapy and radiotherapy-induced anaemia. The simultaneous application of r-HuEPO with chemotherapy can prevent patients with head and neck tumours from developing anaemia or can reduce the extent of the anaemia and the need for transfusion. Comparable effects were observed both in patients undergoing platinum-based and non-platinum-based chemotherapy. The direct correlation between anaemia, tumour hypoxia and poor response to radio and/or chemotherapy has been clinically proven. Recombinant human erythropoietin administration improves the therapeutic outcome and the patients' prognosis.

Once-Weekly Intravenous Administration of Recombinant Human Erythropoietin for Anemia following Hematopoietic Stem Cell Transplantation

Objective:

To determine the response to once-weekly intravenous administration of recombinant human erythropoietin (rHuEPO) in individuals who develop severe anemia following hematopoietic stem cell transplantation (HSCT).

Design:

A serum erythropoietin (EPO) concentration was obtained by chemiluminescence immunoassay in recipients of allogeneic or autologous stem cell transplantation who had developed severe anemia (hemoglobin <8.5 g/dL). If the erythropoietin concentration was not as high as predicted for the degree of anemia, rHuEPO was initiated at a dosage of 40,000 units intravenously once weekly. The medication was administered through a permanent indwelling central venous catheter on an outpatient basis. Hemoglobin concentration was measured at least weekly for up to 12 weeks prior to the administration of rHuEPO, and for an equivalent period following the initiation of therapy. Packed red blood cells were transfused for a hemoglobin concentration <8.5 g/dL. The mean weekly transfusion requirements prior to and following the initiation of rHuEPO were compared.

Results:

Ten consecutive patients who developed severe anemia after allogeneic (n = 8) or autologous (n = 2) HSCT for a variety of hematologic malignancies were eligible for the study. The median age was 43.5 years, and the male to female ratio was 3:7. There was no evidence of renal failure, iron or vitamin deficiency, hemoglobinopathy, or active blood loss. The median EPO concentration was 102 mU/mL. rHuEPO was begun at a median of 41 days following stem cell infusion. Patients received a median dose of 580 units/kg/wk. Two patients developed severe intestinal hemorrhage as a result of acute graft-versus-host disease. The remaining eight individuals received their last transfusion of packed red blood cells a median of 27 days after the initiation of rHuEPO therapy. The mean weekly transfusion requirement prior to and following the commencement of rHuEPO therapy was 0.93 and 0.40, respectively. This difference was statistically significant (p = 0.024).

Conclusions:

rHuEPO 40,000 units intravenously once weekly may reduce packed red blood cell transfusion requirements in some patients who develop severe anemia after HSCT. However, its use should be limited to individuals who are either intolerant of, or unwilling to use, the subcutaneous route of administration.

Erythropoietin, iron, and erythropoiesis

Recent knowledge gained regarding the relationship between erythropoietin, iron, and erythropoiesis in patients with blood loss anemia, with or without recombinant human erythropoietin therapy, has implications for patient management. Under conditions of significant blood loss, erythropoietin therapy, or both, iron-restricted erythropoiesis is evident, even in the presence of storage iron and iron oral supplementation. Intravenous iron therapy in renal dialysis patients undergoing erythropoietin therapy can produce hematologic responses with serum ferritin levels up to 400 μg/L, indicating that traditional biochemical markers of storage iron in patients with anemia caused by chronic disease are unhelpful in the assessment of iron status. Newer measurements of erythrocyte and reticulocyte indices using automated counters show promise in the evaluation of iron-restricted erythropoiesis. Assays for serum erythropoietin and the transferrin receptor are valuable tools for clinical research, but their roles in routine clinical practice remain undefined. The availability of safer intravenous iron preparations allows for carefully controlled studies of their value in patients undergoing erythropoietin therapy or experiencing blood loss, or both.

Erythropoietin, iron, and erythropoiesis

Recent knowledge gained regarding the relationship between erythropoietin, iron, and erythropoiesis in patients with blood loss anemia, with or without recombinant human erythropoietin therapy, has implications for patient management. Under conditions of significant blood loss, erythropoietin therapy, or both, iron-restricted erythropoiesis is evident, even in the presence of storage iron and iron oral supplementation. Intravenous iron therapy in renal dialysis patients undergoing erythropoietin therapy can produce hematologic responses with serum ferritin levels up to 400 μg/L, indicating that traditional biochemical markers of storage iron in patients with anemia caused by chronic disease are unhelpful in the assessment of iron status. Newer measurements of erythrocyte and reticulocyte indices using automated counters show promise in the evaluation of iron-restricted erythropoiesis. Assays for serum erythropoietin and the transferrin receptor are valuable tools for clinical research, but their roles in routine clinical practice remain undefined. The availability of safer intravenous iron preparations allows for carefully controlled studies of their value in patients undergoing erythropoietin therapy or experiencing blood loss, or both.

Anaemia in systemic lupus erythematosus: aetiological profile and the role of erythropoietin

OBJECTIVE

To study the prevalence of different causes of anaemia in patients with systemic lupus erythematosus (SLE) and their associations with immunological and clinical parameters and to evaluate the contribution of erythropoietin (Epo) and anti-erythropoietin (anti-Epo) autoantibodies to the development of SLE anaemia.

METHODS

132 SLE patients with anaemia (defined as haemoglobin of 12 g/dl or less for women and 13.5 g/dl or less for men) from among a total of 345 consecutive SLE patients were prospectively enrolled into the study. Standard haematological and immunological tests were performed and serum Epo and anti-Epo antibodies were assayed.

RESULTS

The identified causes were anaemia of chronic disease (ACD) n=49 (37.1%), iron deficiency anaemia (IDA) n = 47 (35.6%), autoimmune haemolytic anaemia (AHA) n = 19 (14.4%) and other causes n = 17 (12.9%). There was significant heterogeneity in the severity of anaemia between the four groups (p<0.01) with AHA cases being on average more severe. The proportion of patients with anticardiolipin antibodies, low complement levels and anti-dsDNA differed significantly among the four groups; these markers were particularly common in patients with AHA, and uncommon in patients with IDA. Twenty one of 100 tested patients had anti-Epo antibodies. Such antibodies were seen practically only in patients with ACD (odds ratio 3.1, p = 0.041) and in patients with high lupus activity (ECLAM) scores (odds ratio 1.27 per point, p = 0.055). Epo response was inadequate in 42.4% and 41.2% of patients with ACD and AHA, respectively.

CONCLUSIONS

Anaemia in SLE usually takes the form of ACD and IDA, however autoimmune haemolysis is not uncommon. SLE patients with different causes of anaemia differ in regard to several immunological parameters. Epo response is blunted in anaemic SLE patients, particularly those with ACD and AHA.

Effectiveness of recombinant erythropoietin and iron sucrose vs. iron therapy only, in patients with postpartum anaemia and blunted erythropoiesis

BACKGROUND

To compare efficacy between recombinant human erythropoietin (rhEPO) plus parenteral iron vs. iron alone (parenteral vs. oral) in postpartum anaemia.

METHODS

Sixty patients (haemoglobin 8.6 +/- 1.1 g dL-1) were randomized to rhEPO plus intravenous (i.v.) iron sucrose (group 1), rhEPO placebo plus i.v. iron sucrose (group 2), or oral iron alone (group 3), daily for 4 days beginning 48-72 h postpartum. Erythropoiesis and iron status were assessed before, and on 4, 7 and 14 days after, starting therapy.

RESULTS

On day 7 the group 1 haematocrit increase was 7.7 +/- 3.1% vs. 5.3 +/- 1.9% (group 2, P < 0.01) and 4.4 +/- 3.2% (group 3, P < 0.01), and on day 14, 11.3 +/- 2.9% vs. 9.2 +/- 3.4% (group 2, P < 0.05) and 8 +/- 2.8% (group 3, P < 0.01). The odds of achieving a target haematocrit > 32% on day 7 and > 35% on day 14 were higher on rhEPO (1.5-2.7) than on either iron regimen alone. Group 1 reticulocyte counts were also higher on days 4 (P < 0.05 vs. oral iron) and 7 (P < 0.01 vs. oral and parenteral iron).

CONCLUSION

All three regimens were effective in postpartum anaemia, but the haematocrit and reticulocyte responses to rhEPO plus parenteral iron were significantly greater than to iron alone. Benefit was greatest in the blunted erythropoiesis subgroup with elevated post-Caesarean section C-reactive protein levels.

Serum erythropoietin level in anemic cancer patients

Anemia is a frequent complication of cancer and its treatment. A defect in erythropoietin production has been advocated as being the main cause of anemia in cancer patients. We studied serum erythropoietin levels in 74 patients with solid tumors and in a control group consisting of 20 otherwise healthy individuals without any malignancy, who have only iron deficiency anemia. Serum erythropoietin levels were measured by enzyme immunoassay in cancer patients without anemia (n=34), and in anemic cancer patients (n=40); either receiving chemotherapy (n=21) or not (n=19). Anemic cancer patients were found to have decreased response of erythropoietin for a given hemoglobin level (mean, 40.1+/-34.7 u/ml), compared with the patients having only iron deficiency anemia (mean, 69.7+/-68.6 u/ml) (P<0.05). In patients with iron deficiency anemia having no malignancy, erythropoietin response was remarkably high and inversely correlated with the level of hemoglobin (r=-0.69; P=0. 05). Although there was no correlation between hemoglobin and erythropoietin response in cancer anemia (r=-0.07), serum levels of erythropoietin were found to be higher in anemic cancer patients (mean, 40.1+/-34.7 u/ml), compared with cancer patients with normal hemoglobin values (mean, 19.96+/-18.4 u/ml). There was not any statistically significant difference between erythropoietin levels in anemic cancer patients with or without chemotherapy (mean, 43. 7+/-37.7 u/ml and 41.9+/-30.08 u/ml respectively; P>0.05). No difference in serum erythropoietin levels were noted in patients treated with cisplatin or non-cisplatin containing regimens (mean, 48.36+/-33.12 u/ml and 38.55+/-43.52 u/ml, respectively; P>0.05). In this study, we demonstrated that anemia in cancer patients was caused by blunted erythropoietin response, rather than its quantitative deficiency. Serial measurements, however, should be considered in patients receiving chemotherapy.

Effects of neopterin and 7,8-dihydroneopterin on hypoxia-induced renal erythropoietin production

Activation of the human cellular immune system is associated with greatly increased formation of the pteridines neopterin and 7,8-dihydroneopterin. It has been postulated that pteridines play a role in the pathogenesis of the anaemia of inflammation. Herein, we studied effects of pteridines on renal function, primarily on the synthesis of erythropoietin (Epo). The experiments were performed with isolated rat kidneys which were perfused hypoxically (pO2 26 mmHg) at constant pressure (100 mmHg) in a serum-free recirculation system for 3 h. The results show that the rate of the production of Epo was significantly lowered when neopterin or 7,8-dihydroneopterin were added to the perfusate. Neopterin (200 microM) also reduced the renal Epo mRNA level. Both pteridines increased renal vascular resistance. 7,8-Dihydroneopterin lowered urine flow and glomerular filtration rate more potently than neopterin. Renal O2 consumption and parameters of exocrine renal function (fractional reabsorption rates of sodium, glucose and water) were not altered by the pteridines, while the glomerular permeability was greatly increased. These results suggest that activated macrophages may not only inhibit the synthesis of Epo by generating cytokines and reactive O2 species but also by the release of pteridines. In vivo, high concentrations of pteridines in renal tissue may aggravate the anaemia of inflammation.

Are current methods of measurement of erythropoietin (EPO) in human plasma or serum adequate for the diagnosis of polycythaemia vera and the assessment of EPO deficiency?

Current methodology for the immunoassay of erythropoietin (EPO) in human plasma or serum is reviewed, with an emphasis on measurement of EPO concentrations in the low and normal ranges, analytical interference and blood sampling requirements. In only 2 out of 8 research or in-house immunoassays reported since 1987 was there evidence that patients with polycythaemia vera (PV) could be identified, PV being an EPO-independent form of polycythaemia in which EPO concentrations are low in untreated cases. The same was true for only 1 out of 13 currently available kit methods. Remarkable differences in sample stability have been observed with different methods. Measurement of EPO in serum is recommended in most published articles. However, only EDTA plasma seems to be acceptable for the one generally available method with proven high diagnostic sensitivity for PV. It is concluded that most EPO assay methods have not been shown to be adequate for the measurement of the low EPO concentrations, and thus have poor diagnostic sensitivity for PV. It is inferred that they might not be appropriate to assess states of EPO deficiency. Only when a sufficiently sensitive diagnostic method becomes generally available will it be possible to define the various causes of low EPO concentrations. As in other fields of polypeptide hormone measurement, further developments in the field of EPO assay may be expected to be important in diagnostic medicine.

Proinflammatory cytokines lowering erythropoietin production

The plasma level of erythropoietin (Epo) in anemic patients suffering from inflammation is often low in relation to the blood hemoglobin concentration. Various proinflammatory cytokines have been tested for their action on the synthesis of Epo. Interleukin 1 (IL-1) and tumor necrosis factor-alpha(TNF-alpha) suppress Epo gene expression in isolated perfused rat kidneys and in human hepatoma cell cultures. IL-6 inhibits in the kidney, and conflicting results have been reported for its effect on Epo synthesis in hepatic cells. Several other cytokines tested were without effect. Thus, mainly IL-1 and TNF-alpha seem to be responsible for the defect in Epo production in severe systemic and renal inflammatory diseases.

Butyrate trials

The aims of this study were to ascertain tolerability, safety and efficacy of oral isobutyramide (150 mg/kg bw/day) in stimulating fetal hemoglobin production in twelve thalassemia intermedia patients. Patients were treated for 28 days and followed for a further 28 days. Efficacy was monitored by non-alpha/alpha globin chain ratio and percentage of HbF. Five patients experienced increases of non-alpha/alpha ratio ranging between 5.3 and 100% at the end of treatment. Five patients show an increase of HbF ranging between 4.4 and 26%. Their HbF% continues to increase during follow-up period. The analysis of variance for HbF showed a time effect close to significance both in treatment period (p = 0.06) and in follow-up period (p = 0.08). Moreover, to evaluate a possible erythropoietic modification, serum Erythropoietin (sEpo) and serum Transferrin Receptor (sTfR) were evaluated. Serum Epo and sTfR levels were significantly increased during treatment (p < 0.05 vs baseline).

Inhibition of hypoxia-inducible factor 1 activity by nitric oxide donors in hypoxia

Nitric oxide (NO) is known to have various biologic and pathophysiologic effects on organisms. The molecular mechanisms by which NO exerts harmful effects are unknown, although various O2 radicals and ions that result from reactivity of NO are presumed to be involved. Here we report that adaptive cellular response controlled by the transcription factor hypoxia-inducible factor 1 (HIF-1) in hypoxia is suppressed by NO. Induction of erythropoietin and glycolytic aldolase A mRNAs in hypoxically cultured Hep3B cells, a human hepatoma cell line, was completely and partially inhibited, respectively, by the addition of sodium nitroprusside (SNP), which spontaneously releases NO. A reporter plasmid carrying four hypoxia-response element sequences connected to the luciferase structural gene was constructed and transfected into Hep3B cells. Inducibly expressed luciferase activity in hypoxia was inhibited by the addition of SNP and two other structurally different NO donors, S-nitroso-L-glutathione and 3-morpholinosydnonimine, giving IC50 values of 7.8, 211, and 490 microM, respectively. Inhibition by SNP was also observed in Neuro 2A and HeLa cells, indicating that the inhibition was not cell-type-specific. The vascular endothelial growth factor promoter activity that is controlled by HIF-1 was also inhibited by SNP (IC50 = 6.6 microM). Induction generated by the addition of cobalt ion (this treatment mimics hypoxia) was also inhibited by SNP (IC50 = 2.5 microM). Increased luciferase activity expressed by cotransfection of effector plasmids for HIF-1alpha or HIF-1alpha-like factor in hypoxia was also inhibited by the NO donor. We also showed that the inhibition was performed by blocking an activation step of HIF-1alpha to a DNA-binding form.

Predictive models for response to recombinant human erythropoietin (rhEPO) in cancer patients

Response rates vary considerably among cancer patients treated with similar regimens of recom binant human erythropoietin (EPO); conse quently, identifying possible prognostic factors for response is beneficial. Prognostic factors identified in clinical trials include baseline EPO levels, baseline observed-to-predicted ratio of EPO levels, and rapid elevation of hemoglobin levels, reticulocyte count, and soluble trans ferrin receptor. The onset of the acute-phase inflammatory response, which is characterized by elevated C-reactive protein, neopterin, and increased ferritin levels, has also been associ ated with cancer-related anemia. Various models incorporating these prognostic factors have been proposed to predict the value of recombi nant human EPO therapy in anemic cancer pa tients. The clinical studies evaluating predictive algorithms are based on retrospective analyses. Therefore, prospective studies are needed. These predictive algorithms should be designed to use parameters that are widely available and easily interpreted.

Nitric oxide donors suppress erythropoietin production in vitro

Many inflammatory diseases are associated with a hypoproliferative anaemia. Patients with this anaemia often present with serum erythropoietin (EPO) concentrations that are too low for the degree of their anaemia. Proinflammatory cytokines, in addition to their inhibitory effects on proliferation of erythroid progenitors, could contribute to the pathogenesis of this anaemia by reducing EPO production. Because several cytokines stimulate nitric oxide (NO) synthase we propose that nitric oxide might mediate the suppression of EPO production during inflammation. In order to test this hypothesis we investigated the effects of NO donors on 24-h hypoxia-induced EPO production in the hepatocellular carcinoma cell line HepG2. Following application of the NO donors sodium nitroprusside (SNP), 3-morpholinosydnonimine (SIN-1), and S-nitroso-N-acetyl-D,L-penicillamine (SNAP), EPO production was dose-dependently reduced: compared to the untreated control EPO production was lowered by 89% with SNP (1000 microM), by 66% with SIN-1 (1000 microM), and by 72% with SNAP (500 microM). In contrast, 8-bromo-cGMP did not inhibit EPO formation. Since pyrogallol (300 microM) and H2O2 (250 microM) showed a comparable suppression of EPO synthesis, we propose that NO might affect EPO production either by a similar direct influence on the cellular redox state or via increasing the cellular content of reactive oxygen species.

Erythropoietin in the control of red cell production

The understanding of the endocrine regulation of red cell production has been extended greatly since the erythropoietin gene was cloned and recombinant human erythropoietin has become available for experimental and clinical applications. Human erythropoietin is a 30 kDa glycoprotein. It is composed of 165 amino acids and 4 carbohydrate side chains. Studies in rodents have shown that blood-borne erythropoietin originates from peritubular cells, possibly fibroblasts, in the renal cortex and from parenchymal cells in the liver. In addition, erythropoietin mRNA has been demonstrated in spleen, lung and brain. Tissue hypoxia is the main stimulus for erythropoietin synthesis. Erythropoietin gene expression is controlled by DNA-binding proteins, primarily by hypoxia-inducible factor 1. Erythropoietin maintains red cell production by inhibiting apoptosis of erythrocytic progenitors, and by stimulating their proliferation and differentiation into normoblasts. The functional human erythropoietin receptor, a 484-amino acid glycoprotein, is member of the class I cytokine receptor superfamily. Lack of erythropoietin results in anaemia. Recombinant human erythropoietin is efficient for treatment of the anaemia of chronic renal failure. In addition, the drug is increasingly administrated to persons suffering from anaemia of chronic diseases and to surgical patients, thus abolishing the need for homologous red cell transfusion.