How I treat renal anemia.

Anemia is a frequent complication of kidney disease. When severe, it causes symptoms that can be debilitating. The course of anemia tends to track the decline in kidney function, with prevalence increasing in more advanced disease. Although the most common cause is relative erythropoietin deficiency, other factors such as reduced iron availability contribute to the pathobiology. In this review, we use cases to explore the surprising complexity of decision-making in management of renal anemia.

Relationship between protein-energy wasting in adults with chronic hemodialysis and the response to treatment with erythropoietin.

BACKGROUND: It is known that one of the leading causes of morbidity in chronic kidney disease (CKD) is the anemic syndrome. Although the pathogenic mechanisms of anemia are multiple, erythropoietin deficiency appears as the dominant factor. Patients in hemodialysis (HD) have a high prevalence of protein energy wasting (PEW) that may explains the poor response to Erythropoietin (EPO). METHODS: Retrospective cohort study of patients on HD from January to December 2014. The participants were classified according to a diagnostic of PEW using the "Malnutrition Inflammation Score" (MIS) and bioimpedance analysis (BIA) measurement of body composition at the start of erythropoietin therapy and after 3 months of follow up. We performed descriptive statistics and analyzed the differences between groups with and without PEW considering their responsiveness. In addition, we calculated the relative risk of EPO resistance, considering p value < 0.05 as statistically significant. RESULTS: Sixty-one patients ended the follow up. Both groups were similar in basal hemoglobin, hematocrit and other hematopoiesis markers (p = NS). Patients without PEW have a decrease risk for poor response to treatment with EPO (RR = 0.562 [95% CI, 0.329-0.961-]) than those with PEW. Finally, hemoglobin concentrations were evaluated at baseline and every four weeks until week 12, finding a statistically significant improvement only in patients without PEW according MIS (p < 0.05). CONCLUSIONS: PEW is an incremental predictor of poor responsiveness to EPO in HD patients, thus, it is important to consider correcting malnutrition or wasting for a favorable response to treatment with EPO.

Total Synthesis of (+)-Medicarpin.

(+)-Medicarpin has been synthesized asymmetrically for the first time in a linear scalable process with an overall yield of 11%. The two chiral centers were constructed in one step via condensation using a chiral oxazolidinone auxiliary. This method will likely accelerate research on medicarpin as an erythropoietin inducer for erythropoietin-deficient diseases.

[Erythropoietin stimulating agents in chronic kidney disease: indications and contraindications].

Erythropoietin (EPO) deficiency is important complication of chronic kidney disease. It downregulates red cells maturation and production causing renal anemia. It is associated with reduced quality of life, increased risk of blood transfusions and cardiovascular morbidity. It is possible to substitute EPOwith recombinant human EPOor its derivatives - erythropoiesis stimulating agents (ESA). ESA therapy reduces blood transfusions, improves quality of life and can raise hemoglobin to 10-11.5 g/dl. Higher hemoglobin targets bring more harm than benefit - including increased risk for stroke, hypertension and vascular access thrombosis and mortality. Initiation of ESA therapy should be preceded by excluding the other causes of anemia and balancing ESA advantages and disadvantages in every patient. In patients with previous stroke, previous or current malignancy risks of ESA therapy may outweigh the risks of red cell transfusions.

Treatment of erythropoietin deficiency in mice with systemically administered siRNA.

Anemia linked to a relative deficiency of renal erythropoietin production is a significant cause of morbidity and medical expenditures in the developed world. Recombinant erythropoietin is expensive and has been linked to excess cardiovascular events. Moreover, some patients become refractory to erythropoietin because of increased production of factors such as hepcidin. During fetal life, the liver, rather than the kidney, is the major source of erythropoietin. In the present study, we show that it is feasible to reactivate hepatic erythropoietin production and suppress hepcidin levels using systemically delivered siRNAs targeting the EglN prolyl hydroxylases specifically in the liver, leading to improved RBC production in models of anemia caused by either renal insufficiency or chronic inflammation with enhanced hepcidin production.

Endogenous erythropoietin protects neuroretinal function in ischemic retinopathy.

Because retinal ischemia is a common cause of vision loss, we sought to determine the effects of ischemia on neuroretinal function and survival in murine oxygen-induced retinopathy (OIR) and to define the role of endogenous erythropoietin (EPO) in this model. OIR is a reproducible model of ischemia-induced retinal neovascularization; it is used commonly to develop antiangiogenic strategies. We investigated the effects of ischemia in murine OIR on retinal function and neurodegeneration by electroretinography and detailed morphology. OIR was associated with significant neuroretinal dysfunction, with reduced photopic and scotopic ERG responses and reduced b-wave/a-wave ratios consistent with specific inner-retinal dysfunction. OIR resulted in significantly increased apoptosis and atrophy of the inner retina in areas of ischemia. EPO deficiency in heterozygous Epo-Tag transgenic mice was associated with more profound retinal dysfunction after OIR, indicated by a significantly greater suppression of ERG amplitudes, but had no measurable effect on the extent of retinal ischemia, preretinal neovascularization, or neuroretinal degeneration in OIR. Systemic administration of recombinant EPO protected EPO-deficient mice against this additional suppression, but EPO supplementation in wild-type animals with OIR did not rescue neuroretinal dysfunction or degeneration. Murine OIR offers a valuable model of ischemic neuroretinal dysfunction and degeneration in which to investigate adaptive tissue responses and evaluate novel therapeutic approaches. Endogenous EPO can protect neuroretinal function in ischemic retinopathy.

Hsp70 regulates erythropoiesis by preventing caspase-3-mediated cleavage of GATA-1.

Caspase-3 is activated during both terminal differentiation and erythropoietin-starvation-induced apoptosis of human erythroid precursors. The transcription factor GATA-1, which performs an essential function in erythroid differentiation by positively regulating promoters of erythroid and anti-apoptotic genes, is cleaved by caspases in erythroid precursors undergoing cell death upon erythropoietin starvation or engagement of the death receptor Fas. In contrast, by an unknown mechanism, GATA-1 remains uncleaved when these cells undergo terminal differentiation upon stimulation with Epo. Here we show that during differentiation, but not during apoptosis, the chaperone protein Hsp70 protects GATA-1 from caspase-mediated proteolysis. At the onset of caspase activation, Hsp70 co-localizes and interacts with GATA-1 in the nucleus of erythroid precursors undergoing terminal differentiation. In contrast, erythropoietin starvation induces the nuclear export of Hsp70 and the cleavage of GATA-1. In an in vitro assay, Hsp70 protects GATA-1 from caspase-3-mediated proteolysis through its peptide-binding domain. The use of RNA-mediated interference to decrease the Hsp70 content of erythroid precursors cultured in the presence of erythropoietin leads to GATA-1 cleavage, a decrease in haemoglobin content, downregulation of the expression of the anti-apoptotic protein Bcl-X(L), and cell death by apoptosis. These effects are abrogated by the transduction of a caspase-resistant GATA-1 mutant. Thus, in erythroid precursors undergoing terminal differentiation, Hsp70 prevents active caspase-3 from cleaving GATA-1 and inducing apoptosis.

Association of calcium channel blocker use with lower hemoglobin levels in chronic kidney disease.

AIM: To search whether calcium channel blockers (CCBs) are associated with lower hemoglobin levels in chronic kidney disease (CKD) patients who are not on renal replacement therapy (RRT), vitamin D and anti-anemic treatment. PATIENTS AND METHODS: CKD patients were classified into two groups. Patients on CCBs treatment (103 patients) and patients not using CCBs (104 patients) were compared cross-sectionally regarding clinical findings, complete blood count (CBC), biochemistry and regular medication use. Patients with polycystic kidney disease, comorbidities that could influence CBC other than iron deficiency of obscure origin, patients receiving RRT, erythropoietin (EPO), vitamin D, phosphate binders and drugs that could influence CBC were excluded. Under dependent variable of CCB use, all significantly different independent variables were subjected to multivariate binary logistic regression analysis (MBLRA). RESULTS: Lower hemoglobin, lower bilirubinemia, higher serum EPO, higher systolic blood pressure were observed in CCB users. Two groups were similar concerning age, gender, BMI, CKD etiology, CKD stage, pretibial edema prevalence, cardiothoracic index, diastolic blood pressure, corrected reticulocyte count, BUN, creatinine, eGFR, proBNP, parathormone, alkaline phosphatase, phosphorous, corrected calcemia, sCRP, relative EPO deficiency and prevalence of relative EPO deficient patients. Groups were comparable regarding comorbidities, types and usage frequencies of all antihypertensive medications other than CCBs. Higher systolic blood pressure and lower hemoglobin were significantly associated with CCB use after MBLRA. CONCLUSIONS: Hemoglobin was significantly lower in CCB users compared to non-users, among CKD patients who did not receive RRT, EPO, phosphate binders, vitamin D, iron, vitamin B12 and folic acid.

Mechanisms of anemia in CKD.

Anemia is a common feature of CKD associated with poor outcomes. The current management of patients with anemia in CKD is controversial, with recent clinical trials demonstrating increased morbidity and mortality related to erythropoiesis stimulating agents. Here, we examine recent insights into the molecular mechanisms underlying anemia of CKD. These insights hold promise for the development of new diagnostic tests and therapies that directly target the pathophysiologic processes underlying this form of anemia.

[Management of renal anemia in 2013]. / Prise en charge de l'anémie rénale en 2013.

Anemia occurs frequently in patients with chronic kidney disease (CKD), especially in the later stages, and the main etiologies are decreased production of erythropoietin (EPO) as well as iron and vitamin deficiencies. For these reasons, it is essential to detect anemia in patients with CKD and to investigate the etiology. If anemia (Hb < 100 g/l) persists after substitution of deficiencies, treatment with recombinant human erythropoietin (rHuEPO) should be considered. New guidelines (KDIGO - August 2012) have just been published by the National Kidney Foundation (NKF) for the management of anemia in patients with renal failure. This article reviews the principles and innovations in management in 2013.

[Early erythropoietin deficiency in diabetic kidney lesion].

AIM: To evaluate the renal production of erythropoietin (EPO) in relation to filtration function in patients with diabetic kidney lesion. SUBJECTS AND METHODS: The investigation enrolled 183 patients with types 1 and 2 diabetes mellitus (DM), of whom 128 were diagnosed as having diabetic kidney lesion. Serum EPO levels were measured by enzyme immunoassay. Patients who had a glomerular filtration rate (GFR) of below 15 ml/min/1.73 m2 and received erythropoiesis-stimulating agents were excluded from the investigation. RESULTS: The mean serum EPO levels in the patients with diabetic kidney lesion did not vary with the presence or absence of anemia, the degree of albuminuria, or GFR. A physiological inverse relationship was found between the level of EPO and that of hemoglobin in the blood of the patients with DM without kidney disease and in those with renal lesion and GFR > or = 60 ml/min/1.73 m2. The magnitude of the association of the values increased as GFR was higher. The level of EPO was found to be unassociated with hemoglobin in patients with GFR < 60 ml/min/1.73 m2. CONCLUSION: In the patients with diabetic kidney lesion, serum EPO concentrations did not depend on the stage of chronic kidney disease and the degree of albuminuria in spite of more severe anemia as renal failure progressed. These patients showed inadequate EPO production just in early diminished renal filtration function.

Standard clinical practice underestimates the role and significance of erythropoietin deficiency in sickle cell disease.

In sickle cell disease (SCD), vigorous reticulocytosis is required to partially compensate for chronic hemolytic anaemia. Consequently, early renal damage, insufficient to cause azotemia but sufficient to cause erythropoietin deficiency and chronic relative reticulocytopenia (chRR), could have severe clinical consequences. chRR was defined as reticulocytes <250×10(9) /l despite haemoglobin <9 g/dl on ≥ two occasions ≥4 weeks apart. The influence of multiple variables including chRR on time from first clinic visit to death was evaluated in 306 SCD patients. In univariate analyses, fetal haemoglobin, indices of renal damage (serum creatinine, proteinuria), chRR and age, were associated with rate of death. In multivariate analysis, only age and chRR (Hazard ratio 3·6, 95% CI 2·049-6·327, P<0·0001) were significant, underlining that chRR could be an early and important clinical consequence of renal damage. Even in chRR patients with normal serum creatinine levels, low haemoglobin and low reticulocyte counts were associated with low erythropoietin levels. In the general population, evaluation of erythropoietin levels is prompted by the combination of anaemia and abnormal serum creatinine. In SCD patients, this standard approach can miss a substantial risk factor for early death. chRR could be a practical and important criterion for diagnosis of erythropoietin deficiency in SCD.

Anemia in Cardio-Renal Syndrome: clinical impact and pathophysiologic mechanisms.

Anemia is a disease that is often associated with heart failure (HF) and renal insufficiency (RI). This unfavorable triad of conditions has been called Cardio-Renal-Anemia Syndrome (CRS). The association of HF, RI, and anemia is poorly reported in multicenter clinical trials, so the pathophysiologic mechanisms and treatment options need to be better defined. When CRS patients develop anemia, a "perfect storm" often occurs: HF and RI cause anemia which will worsen the first two conditions. Anemia appears to be the result of complex interactions between cardiac performance, bone marrow homeostasis, renal dysfunction, and various drug side effects. However, neurohormonal and inflammatory activities play a key role in the beginning and progression of the disease. As a consequence, endogenous erythropoietin activity dysfunction with inadequate production and tissue resistance occurs. Despite the advances of therapy in the neurohormonal activation blockade, mortality and hospitalization in HF still remain unacceptably high, suggesting that specific comorbidity treatments could have a significant positive prognostic impact. Anemia should be recognized as one of the novel targets in HF treatment.

The role of erythropoiesis stimulating agents and intravenous (IV) iron in the cardio renal anemia syndrome.

Anemia is common in Congestive Heart Failure (CHF) and is associated with an increased mortality, morbidity and progressive renal failure. The most common causes of the anemia in CHF are (1) the associated Chronic Kidney Disease (CKD), which causes depression of erythropoietin (EPO) production in the kidney, and (2) excessive cytokine production in CHF, which can cause both depression of erythropoietin production in the kidney and depression of erythropoietin response in the bone marrow. The cytokines can also induce iron deficiency by increasing hepcidin production from the liver, which both reduces gastrointestinal iron absorption and reduces iron release from iron stores located in the macrophages and hepatocytes. It appears that iron deficiency is very common in CHF and is rarely recognized or treated. The iron deficiency can cause a thrombocytosis that might contribute to cardiovascular complications in both CHF and CKD and is reversible with iron treatment. Thus, attempts to control this anemia in CHF will have to take into consideration both the use of both Erythropoiesis Stimulating Agents (ESA) such as EPO and oral and, probably more importantly, intravenous (IV) iron. Many studies of anemia in CHF with ESA and oral or IV iron and even with IV iron without ESA have shown a positive effect on hospitalization, New York Heart Association functional class, cardiac and renal function, quality of life, exercise capacity and reduced Beta Natriuretic Peptide and have not demonstrated an increase in cardiovascular damage related to the therapy. However, adequately powered long-term placebo-controlled studies of ESA and of IV iron in CHF are still needed and are currently being carried out.

Erythropoietin, GDF15, IL6, hepcidin and testosterone levels in a large cohort of elderly individuals with anaemia of known and unknown cause.

Epidemiologic studies have documented an increasing frequency of anaemia in individuals 65 yrs and older. Elderly individuals with anaemia have been categorised into the following: those with chronic disease, those with iron, B12 or folate deficiency and those with anaemia of unknown aetiology (AUE). There is considerable interest and debate as to whether AUE has an inflammatory component, is caused by cytokine dysregulation affecting production or response to erythropoietin (EPO) or iron availability or represents a novel pathologic process. Here, we compare a large cohort of AUE cases with a matched, non-anaemic control group and with individuals who have anaemia of defined cause. IL-6, hepcidin, GDF15, EPO and testosterone levels were compared. IL6 and hepcidin levels did not differ significantly between AUE and control groups, indicating that inflammation or iron restriction is not central feature of anaemia in this group. GDF15 levels were significantly elevated when comparing AUE with controls and were markedly elevated in patients with renal disease. Testosterone levels were lower in men from the AUE group compared with non-anaemic controls. EPO levels in the AUE group were increased relative to controls but were inappropriately low for the degree of anaemia. Our data indicate that an impaired EPO response, in the absence of evidence for iron restriction or inflammation, is characteristic of AUE.

Clinical and genetic markers of erythropoietin deficiency anemia in chronic kidney disease (predialysis) patients.

Aim: To determine the clinical and genetic markers associated with erythropoietin deficiency anemia in predialysis individuals. Materials & methods: Patients were categorized into cases and control group. Demographic characteristics and clinical parameters were obtained from medical record review and serum EPO and ferritin were obtained with ELISA. HIF-1α (rs2057482), IL-1ß (rs1143627) and EPO (rs1617640) gene polymorphism were genotyped. Results: Female gender, glomerular filtration rate, treatment with hematinics, anticoagulant and diuretic were strong predictors of EPO-deficient anemia in predialysis chronic kidney disease patients. Genetic polymorphism in the HIF-1α recessive model was associated with non-EPO-deficiency, followed by EPO recessive allele associated with low-serum erythropoietin and IL-1ß recessive model with low hemoglobin level. Conclusion: EPO-deficiency anemia can be diagnosed more conveniently in the presence of biomarkers.

Marrow suppression with myelodysplastic features, hypoerythropoetinemia, and lipotrophic proptosis due to rosiglitazone.

Thiazolidinediones (TZDs) are frequently used pharmacotherapeutics for type II diabetes mellitus, which exert their effect through peroxisomal proliferator agonist receptor (PPAR) mediated increased insulin sensitivity. TZDs are known to cause marrow suppression and to stimulate adipogenesis. Case and cohort studies show TZDs worsen thyroid-associated orbitopathy. We present a case consistent with earlier reports of marrow suppressive pancytopenia manifesting as myelodysplastic syndrome, a new implication of hypoerythropoetinemia, and non-Graves'-associated proliferative proptosis.

Anemia of chronic disease and defective erythropoietin production in patients with celiac disease.

BACKGROUND: Anemia due to hematinic deficiencies is common in patients with untreated celiac disease. Although celiac disease is a chronic condition characterized by an intense inflammatory response of the intestinal mucosa, scant data are available about the prevalence of anemia of chronic disease in celiac disease. DESIGN AND METHODS: One hundred and fifty-two patients with celiac disease at presentation were studied. Anemia was investigated by determining complete blood counts, body iron status, serum levels of the soluble transferrin receptor, erythropoietin, prohepcidin and interferon-gamma. Genotyping for HFE mutations associated with hereditary hemochromatosis was performed. Fifty-three anemic patients were re-evaluated for hematologic response after 1 year on a gluten-free diet. RESULTS: At the time of diagnosis of celiac disease the prevalence of anemia was 34%. Fifty-three out of 65 anemic patients had either iron and/or vitamin deficiency (folate, vitamin B(12)). Hereditary hemochromatosis mutations did not affect the prevalence of anemia. In 11 cases iron status parameters were indicative of anemia of chronic disease, sometimes in association with iron deficiency (6 patients). Patients with anemia of chronic disease had low levels of erythropoietin for the degree of anemia and increased serum interferon-gamma. In most cases anemia improved following a gluten-free diet, response rates being similar in anemia of chronic disease and in anemia due to hematinic deficiencies. CONCLUSIONS: Our study shows that, in addition to iron and vitamin deficiencies, anemia of chronic disease has a significant role in some patients with celiac disease. Suppression of intestinal inflammatory changes as a result of a gluten-free diet improves anemia by correcting iron and vitamin malabsorption as well as mechanisms contributing to anemia of chronic disease.