Erythropoiesis stimulating agents: approaches to modulate activity

A short-term intervention of ingesting iron along with methionine and threonine leads to a higher hemoglobin level than that with iron alone in young healthy women: a randomized, double-blind, parallel-group, comparative study

PURPOSE

Enhancing iron absorption and utilization is important for amelioration iron status faster and thereby, for improving quality of life. Dietary protein and amino acids, including methionine and threonine, have been reported to facilitate the absorption and utilization of dietary iron. Here, we investigated the effect of combined ingestion of methionine, threonine, and iron on the improvement of iron status during a short-term intervention, by comparing that with iron ingestion alone in healthy young women.

METHODS

This was a randomized, double-blind, parallel-group, comparative study with 45 participants (aged 20-39) randomly assigned to three groups (n = 15 each): one group was administered 200 mg methionine, 400 mg threonine, and 6 mg iron once daily (FEMT); another ingested 6 mg iron alone (FE); and the third group ingested a placebo (PCG). Blood samples and dietary nutrient data were collected before the intervention (week 0) and after 2, 4, and 6 weeks. Serum iron, hemoglobin, transferrin, and ferritin levels were measured.

RESULTS

Blood hemoglobin levels were significantly higher in the FEMT than in the FE group (P < 0.05) at week 4. Serum iron, transferrin, and ferritin levels were not changed across groups. In addition, our analyses showed that the observed increase in hemoglobin levels was affected by the intervention rather than changes in dietary nutrient intake.

CONCLUSIONS

Ingestion of methionine and threonine with low doses of iron leads to a higher hemoglobin levels than that with iron alone in a short period of 4 weeks.

TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trial Registry (UMIN000046621).

Association between Hematological Indicesand Disease Activity in Patients with Rheumatoid Arthritis Treated with Janus Kinase Inhibitors for 24 Weeks

Background and Objective: Hematological indices have been considered reliable markers for assessment of disease activity in rheumatoid arthritis (RA). This study assessed whether hematological indices reflect changes in disease activity in patients with RA treated with Janus kinase (JAK) inhibitors. Materials and Methods: This study recruited 123 patients with RA who completed a regimen of JAK inhibitors, including baricitinib or tofacitinib, for 24 weeks, and 80 age- and sex-matched healthy control subjects. Hematological indices were systemic immune-inflammation index (SII), neutrophil-to-hemoglobin and lymphocyte (NHL) score, neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR). Disease Activity Score 28 joints using erythrocyte sedimentation rate (DAS28-ESR) was evaluated as a measure of RA disease activity. Results: At baseline, patients with RA had a significantly higher SII, NHL score, NLR, and PLR than controls (p < 0.001 for all). SII, NHL score, NLR, and PLR at baseline were associated with DAS28-ESR (p < 0.05 for all). Changes in SII, NHL score, NLR, and PLR were associated with those in DAS28-ESR during treatment with JAK inhibitors. Such treatment markedly decreased SII, NHL score, and NLR values compared to those at baseline (p < 0.001 for all) but did not decrease PLR (p = 0.056). There were no differences in changes in SII, NHL score, NLR, and PLR between baricitinib and tofacitinib treatments. No hematological index showed predictive potential with respect to non-response to JAK inhibitor treatment. Conclusions: This study showed that hematological indices might be useful in monitoring changes in disease activity in patients with RA treated with JAK inhibitors.

The Effect of Erythropoietin and Its Derivatives on Ischemic Stroke Therapy: A Comprehensive Review

Numerous studies explored the therapeutic effects of erythropoietin (EPO) on neurodegenerative diseases. Few studies provided comprehensive and latest knowledge of EPO treatment for ischemic stroke. In the present review, we introduced the structure, expression, function of EPO, and its receptors in the central nervous system. Furthermore, we comprehensively discussed EPO treatment in pre-clinical studies, clinical trials, and its therapeutic mechanisms including suppressing inflammation. Finally, advanced studies of the therapy of EPO derivatives in ischemic stroke were also discussed. We wish to provide valuable information on EPO and EPO derivatives’ treatment for ischemic stroke for basic researchers and clinicians to accelerate the process of their clinical applications.

The GG genotype of erythropoietin rs1617640 polymorphism affects the risk of proliferative diabetic retinopathy in Slovenian subjects with type 2 diabetes mellitus: enemy or ally?

PURPOSE

The aim of this study was to investigate the relationship between erythropoietin rs1617640 polymorphism and proliferative diabetic retinopathy (PDR) in Slovenian subjects with type 2 diabetes mellitus. The second aim was to find whether erythropoietin expression in fibrovascular membranes varies among individuals carrying different genotypes of the rs1617640.

METHODS

This was a retrospective cross-sectional study based on 797 unrelated Slovenian (Caucasian) participants with type 2 diabetes mellitus. The study group consisted of 217 cases with PDR and 580 controls without clinical signs of diabetic retinopathy. Each subject was genotyped for rs1617640 polymorphism. Fibrovascular membranes from 27 subjects who underwent vitreoretinal surgery were analysed with immunohistochemistry. We searched for expression of erythropoietin, its cognate receptor and for a pan-endothelial marker CD-34.

RESULTS

Our results show that subjects carrying a minor GG genotype had significantly higher risk for PDR in both unadjusted (p = 0.02) and adjusted (p = 0.04) recessive genetic models. Subjects with the GG genotype had a 1.6-fold increased risk of developing PDR compared to subjects carrying the major T allele. In fibrovascular membranes from subjects with PDR, the mean number of cells expressing EPO was significantly higher in G allele carriers compared to the homozygotes for the common T allele.

CONCLUSION

In Slovenian subjects with type 2 diabetes mellitus, a significant increased risk of PDR was found in GG carriers of the erythropoietin gene rs1617640 polymorphism.

Insights into Potential Targets for Therapeutic Intervention in Epilepsy

Epilepsy is a chronic brain disease that affects approximately 65 million people worldwide. However, despite the continuous development of antiepileptic drugs, over 30% patients with epilepsy progress to drug-resistant epilepsy. For this reason, it is a high priority objective in preclinical research to find novel therapeutic targets and to develop effective drugs that prevent or reverse the molecular mechanisms underlying epilepsy progression. Among these potential therapeutic targets, we highlight currently available information involving signaling pathways (Wnt/β-catenin, Mammalian Target of Rapamycin (mTOR) signaling and zinc signaling), enzymes (carbonic anhydrase), proteins (erythropoietin, copine 6 and complement system), channels (Transient Receptor Potential Vanilloid Type 1 (TRPV1) channel) and receptors (galanin and melatonin receptors). All of them have demonstrated a certain degree of efficacy not only in controlling seizures but also in displaying neuroprotective activity and in modifying the progression of epilepsy. Although some research with these specific targets has been done in relation with epilepsy, they have not been fully explored as potential therapeutic targets that could help address the unsolved issue of drug-resistant epilepsy and develop new antiseizure therapies for the treatment of epilepsy.

Williams G, Brocchini S, Awwad S. Injectables and Depots to Prolong Drug Action of Proteins and Peptides

Proteins and peptides have emerged in recent years to treat a wide range of multifaceted diseases such as cancer, diabetes and inflammation. The emergence of polypeptides has yielded advancements in the fields of biopharmaceutical production and formulation. Polypeptides often display poor pharmacokinetics, limited permeability across biological barriers, suboptimal biodistribution, and some proclivity for immunogenicity. Frequent administration of polypeptides is generally required to maintain adequate therapeutic levels, which can limit efficacy and compliance while increasing adverse reactions. Many strategies to increase the duration of action of therapeutic polypeptides have been described with many clinical products having been developed. This review describes approaches to optimise polypeptide delivery organised by the commonly used routes of administration. Future innovations in formulation may hold the key to the continued successful development of proteins and peptides with optimal clinical properties.

Engineered human FcγRIIa fusion: A novel strategy to extend serum half-life of therapeutic proteins

The immunoglobulin G (IgG) molecule has a long circulating serum half-life (~3 weeks) through pH- dependent FcRn binding-mediated recycling. To hijack the intracellular trafficking and recycling mechanism of IgG as a way to extend serum persistence of non-antibody therapeutic proteins, we have evolved the ectodomain of a low-affinity human FcγRIIa for enhanced binding to the lower hinge and upper CH2 region of IgG, which is very far from the FcRn binding site (CH2-CH3 interface). High-throughput library screening enabled isolation of an FcγRIIa variant (2A45.1) with 32-fold increased binding affinity to human IgG1 Fc (equilibrium dissociation constant: 9.04 × 10^-7  M for wild type FcγRIIa and 2.82 × 10^-8  M for 2A45.1) and significantly improved affinity to mouse serum IgG compared to wild type human FcγRIIa. The in vivo pharmacokinetic profile of PD-L1 fused with engineered FcγRIIa (PD-L1-2A45.1) was compared with that of PD-L1 fused with wild type FcγRIIa (PD-L1-wild type FcγRIIa) and human PD-L1 in mice. PD-L1-2A45.1 showed 11.7- and 9.7-fold prolonged circulating half-life (t_1/2 ) compared to PD-L1 when administered intravenously and intraperitoneally, respectively. In addition, the AUC_inf of PD-L1-2A45.1 was two-fold higher compared to that of PD-L1-wild type FcγRIIa. These results demonstrate that engineered FcγRIIa fusion offers a novel and successful strategy for prolonging serum half-life of therapeutic proteins.

Neuroprotective effects of EpoL against oxidative stress induced by soluble oligomers of Aβ peptide

Erythropoietin is a glycoproteic hormone that regulates hematopoiesis by acting on its specific receptor (EpoR). The expression of EpoR in the central nervous system (CNS) suggests a role for this hormone in the brain. Recently, we developed a new Epo variant without hematopoietic activity called EpoL, which showed marked neuroprotective effects against oxidative stress in brain ischemia related models. In this study, we have evaluated the neuroprotective effects of EpoL against oxidative stress induced by chronic treatment with Aβ. Our results show that EpoL was neuroprotective against Aβ-induced toxicity by a mechanism that implicates EpoR, reduction in reactive oxygen species, and reduction in astrogliosis. Furthermore, EpoL treatment improved calcium handling and SV2 levels. Interestingly, the neuroprotective effect of EpoL against oxidative stress induced by chronic Aβ treatment was achieved at a concentration 10 times lower than that of Epo. In conclusion, EpoL, a new variant of Epo without hematopoietic activity, is of potential interest for the treatment of diseases related to oxidative stress in the CNS such as Alzheimer disease.

Becquer M, Colom Y, Gil H, Polo JC, Castañeda G, Jiménez-Vélez B, Duconge J, Fernández-Sánchez EM. A comparative pharmacokinetic and pharmacodynamic study of two novel Cuban PEGylated rHuEPO versus MIRCERA® and ior®EPOCIM

CONTEXT

The recombinant human erythropoietin (rHuEPO) stimulates the erythropoiesis process. Because this glycoprotein has a short half-life, it needs to be administrated two to three times a week. One of the technics to solve this issue is the PEGgilation.

AIMS

To evaluate the pharmacokinetics (PK) and pharmacodynamics of two new branched PEGylated erythropoietins (i.e., an asymmetric 32 kDa-PEG₂-rHuEPO and a symmetric 40 kDa-PEG₂-rHuEPO molecule) compared to non-PEGylated ior^®EPOCIM and MIRCERA^®.

METHODS

Serum concentrations of both PEGylated and non-PEGylated erythropoietins were measured at various time points in order to determine PK parameters using non-compartmental analysis approach. The reticulocyte (%), erythrocyte count and hemoglobin levels were ascertained in order to compare the effect of these molecules after administrating a single intravenous dose (10 μg/kg) of each product in male New Zealand rabbits.

RESULTS

Both branched PEGylated erythropoietin forms exhibited half-lives that were significantly longer than ior^®EPOCIM (p<0.05), but not statistically different to MIRCERA^®. The mean elimination half-life increased from 4 h (ior^®EPOCIM) to 131 h for the 32 kDa-PEG₂-rHuEPO and 119 h for the 40 kDa-PEG₂-rHuEPO. Conversely, MIRCERA^® exhibits a half-life of 64 h. Both PEGylated erythropoietin products significantly enhanced the stimulating effect on reticulocytes and erythrocytes formation, as well as on hemoglobin levels, when compared to ior^®EPOCIM treatment up to 42 days post-dose.

CONCLUSIONS

The PEGylation strategy employed in this study is an effective method to modify the pharmacokinetics and pharmacodynamics of rHuEPO molecule achieving higher half-lives and, therefore, longer in vivo bioactivity. Both of the branched PEGylated-EPO forms tested are promising candidates for human testing.

Neuroprotective effect of a new variant of Epo nonhematopoietic against oxidative stress

Human erythropoietin is mainly recognized for its hematopoietic function; however, by binding to its receptor (EpoR), it can activate different signaling pathways as STAT, PI3K, MAPK and RAS to increase cellular differentiation or provide neuroprotective effects, among others. A recombinant human erythropoietin variant with low glycosylation and without hematopoietic effect (EpoL) was purified from skimmed goat milk. Recombinant human erythropoietin (Epo) was obtained from CHO cell line and used as control to compare EpoL effects. Neuroprotection studies were performed in PC12 cells and rat hippocampal slices. Cells were pretreated during 1h with EpoL or Epo and exposed to oxidative agents (H2O2 or FCCP); cell viability was assayed at the end of the experiment by the MTT method. Hippocampal slices were exposed to 15min of oxygen and glucose deprivation (OGD) and the neuroprotective drugs EpoL or Epo were incubated for 2h post-OGD in re-oxygenated medium. Cell cultures stressed with oxidative agents, and pretreated with EpoL, showed neuroprotective effects of 30% at a concentration 10 times lower than that of Epo. Moreover, similar differences were observed in OGD ex vivo assays. Neuroprotection elicited by EpoL was lost when an antibody against EpoR was present, indicating that its effect is EpoR-dependent. In conclusion, our results suggest that EpoL has a more potent neuroprotective profile than Epo against oxidative stress, mediated by activation of EpoR, thus EpoL represents an important target to develop a potential biopharmaceutical to treat different central nervous system pathologies related to oxidative stress such as stroke or neurodegenerative diseases.

Using Chemical Synthesis To Study and Apply Protein Glycosylation

Protein glycosylation is one of the most common post-translational modifications and can influence many properties of proteins. Abnormal protein glycosylation can lead to protein malfunction and serious disease. While appreciation of glycosylation's importance is growing in the scientific community, especially in recent years, a lack of homogeneous glycoproteins with well-defined glycan structures has made it difficult to understand the correlation between the structure of glycoproteins and their properties at a quantitative level. This has been a significant limitation on rational applications of glycosylation and on optimizing glycoprotein properties. Through the extraordinary efforts of chemists, it is now feasible to use chemical synthesis to produce collections of homogeneous glycoforms with systematic variations in amino acid sequence, glycosidic linkage, anomeric configuration, and glycan structure. Such a technical advance has greatly facilitated the study and application of protein glycosylation. This Perspective highlights some representative work in this research area, with the goal of inspiring and encouraging more scientists to pursue the glycosciences.

Neuroprotective effects of erythropoietin on neurodegenerative and ischemic brain diseases: the role of erythropoietin receptor

Erythropoietin (Epo) is a fundamental hormone in the regulation of hematopoiesis, and other secondary roles mediated by the binding of the hormone to its specific receptor (EpoR), which leads to an activation of key signaling pathways that induce an increase in cell differentiation, apoptosis control and neuroprotection. It has been suggested that their function depends on final conformation of glycosylations, related with affinity to the receptor and its half-life. The presence of EpoR has been reported in different tissues including central nervous system, where it has been demonstrated to exert a neuroprotective function against oxidative stress conditions, such as ischemic injury and neurodegenerative diseases. There is also evidence of an increase in EpoR expression in brain cell lysates of Alzheimer's patients with respect to healthy patients. These results are related with extensive in vitro experimental data of neuroprotection obtained from cell lines, primary cell cultures and hippocampal slices. Additionally, this data is correlated with in vivo experiments (water maze test) in mouse models of Alzheimer's disease where Epo treatment improved cognitive function. These studies support the idea that receptor activation induces a neuroprotective effect in neurodegenerative disorders including dementias, and especially Alzheimer's disease. Taken together, available evidence suggests that Epo appears to be a central element for EpoR activation and neuroprotective properties in the central nervous system. In this review, we will describe the mechanisms associated with neuroprotection and its relation with the activation of EpoR in order with identify new targets to develop pharmacological strategies.

Continuous erythropoiesis receptor activator (CERA) for the anaemia of chronic kidney disease

BACKGROUND

Continuous erythropoiesis receptor activator (CERA) is a newer, longer acting ESA which might be preferred to other ESAs (epoetin or darbepoetin) based on its lower frequency of administration. Different dosing requirements and molecular characteristics of CERA compared with other ESAs may lead to different health outcomes (mortality, cardiovascular events, quality of life) in people with anaemia and chronic kidney disease (CKD).

OBJECTIVES

To assess benefits and harms of CERA compared with other epoetins (darbepoetin alfa and epoetin alfa or beta) or placebo/no treatment or CERA with differing strategy of administration for anaemia in individuals with CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register to 13 June 2017 through contact with the Information Specialist using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE, and EMBASE; handsearching conference proceedings; and searching the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of at least three months' duration, comparing CERA with a different ESA (darbepoetin alfa or epoetin alfa or beta) or placebo or standard care or versus CERA with different strategies for administration in people with any stage of CKD.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent investigators. We summarised patient-centred outcomes (all-cause and cardiovascular mortality, major adverse cardiovascular events, red cell blood transfusion, iron therapy, cancer, hypertension, seizures, dialysis vascular access thrombosis, drug injection-related events, hyperkalaemia and health-related quality of life and haemoglobin levels) using random effects meta-analysis. Treatment estimates were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean differences or standardized mean difference with 95% CI for continuous outcomes.

MAIN RESULTS

We included 27 studies involving 5410 adults with CKD. Seven studies (1273 participants) involved people not requiring dialysis, 19 studies (4209 participants) involved people treated with dialysis and one study (71 participants) evaluated treatment in recipients of a kidney transplant. Treatment was given for 24 weeks on average. No data were available for children with CKD. Studies were generally at high or unclear risk of bias from allocation concealment and blinding of outcomes. Only two studies masked participants and investigators to treatment allocation. One study compared CERA with placebo, nine studies CERA with epoetin alfa or beta, nine studies CERA with darbepoetin alfa, and two studies compared CERA with epoetin alfa or beta and darbepoetin alfa. Three studies assessed the effects of differing frequencies of CERA administration and five assessed differing CERA doses.There was low certainty evidence that CERA had little or no effects on mortality (RR 1.07, 95% CI 0.73 to 1.57; RR 1.11, 95% CI 0.75 to 1.65), major adverse cardiovascular events (RR 5.09, 95% CI 0.25 to 105.23; RR 5.56, 95% CI 0.99 to 31.30), hypertension (RR 1.01, 95% CI 0.75 to 1.37; RR 1.00, 95% CI 0.79 to 1.28), need for blood transfusion (RR 1.02, 95% CI 0.72 to 1.46; RR 0.94, 95% CI 0.55 to 1.61), or additional iron therapy (RR 1.03, 95% CI 0.91 to 1.15; RR 0.99, 95% CI 0.95 to 1.03) compared to epoetin alfa/beta or darbepoetin alfa respectively. There was insufficient evidence to compare the effect of CERA to placebo on clinical outcomes. Only one low quality study reported that CERA compared to placebo might lead to little or no difference in the risk of major cardiovascular events (RR 2.97, 95% CI 0.31 to 28.18) and hypertension ((RR 0.73, 95% CI 0.35 to 1.52). There was low certainty evidence that different doses (higher versus lower) or frequency (twice versus once monthly) of CERA administration had little or no different effect on all-cause mortality (RR 3.95, 95% CI 0.17 to 91.61; RR 0.97, 95% CI 0.56 to 1.66), hypertension (RR 0.45, 95% CI 0.08 to 2.52; RR 0.85, 95% CI 0.60 to 1.21), and blood cell transfusions (RR 4.16, 95% CI 0.89 to 19.53; RR 0.91, 95% CI 0.51 to 1.62). No studies reported comparative treatment effects of different ESAs on health-related quality of life.

AUTHORS' CONCLUSIONS

There is low certainty evidence that CERA has little or no effects on patient-centred outcomes compared with placebo, epoetin alfa or beta or darbepoetin alfa for adults with CKD. The effects of CERA among children who have CKD have not studied in RCTs.

Development of an in vitro Bioassay for Recombinant Human Erythropoietin (rHuEPO) Based on Proliferative Stimulation of an Erythroid Cell Line and Analysis of Sialic Acid Dependent Microheterogeneity: UT-7 Cell Bioassay

Determination of biological activity and its comparison with clinical behavior is important in the quality assessment of therapeutic glycoproteins. In vivo studies are usually employed for evaluating bioactivity of these glycomolecules. However, alternative methods are required to simplify the bioassay and avoid ethical issues associated with in vivo studies. Negatively charged sialic acid residues are known to be critical for in vivo bioactivity of rHuEPO. To address this need, we employed the human acute myeloid leukemia cell line UT-7 for the determination of proliferative stimulation induced by rHuEPO. Relative potencies of various intact and sugar-trimmed rHuEPO preparations were estimated using the International Standard for Human r-DNA derived EPO (87/684) as a reference for bioactivity. The cellular response was measured with a multi-channel photometer using a colorimetric microassay, based on the metabolism of the Resazurin sodium by cell viability. For a resourceful probing of physiological features of rHuEPO with significance, we obtained partly or completely desialylated rHuEPO digested by the neuraminidase enzyme without degradation of carbohydrates. Two-fold higher specific activity was shown by asialoerythropoietin in in vitro analysis compared with the sialoerythropoietin. Further, computational studies were also carried out to construct the 3D model of the erythropoietin (EPO) protein structure using standard comparative modeling methods. The quality of the model was validated using Procheck and protein structure analysis (ProSA) server tools. N-glycan units were constructed; moreover, EPO protein was glycosylated at potential glycosylation amino acid residue sites. The method described should be suitable for potency assessments of pharmaceutical formulations of rHuEPO (European Pharmacopeia, 2016).

Hepcidin: Homeostasis and Diseases Related to Iron Metabolism

Iron is an essential metal for cell survival that is regulated by the peptide hormone hepcidin. However, its influence on certain diseases is directly related to iron metabolism or secondary to underlying diseases. Genetic alterations influence the serum hepcidin concentration, which can lead to an iron overload in tissues, as observed in haemochromatosis, in which serum hepcidin or defective hepcidin synthesis is observed. Another genetic imbalance of iron is iron-refractory anaemia, in which serum concentrations of hepcidin are increased, precluding the flow and efflux of extra- and intracellular iron. During the pathogenesis of certain diseases, the resulting oxidative stress, as well as the increase in inflammatory cytokines, influences the transcription of the HAMP gene to generate a secondary anaemia due to the increase in the serum concentration of hepcidin. To date, there is no available drug to inhibit or enhance hepcidin transcription, mostly due to the cytotoxicity described in the in vitro models. The proposed therapeutic targets are still in the early stages of clinical trials. Some candidates are promising, such as heparin derivatives and minihepcidins. This review describes the main pathways of systemic and genetic regulation of hepcidin, as well as its influence on the disorders related to iron metabolism.

Half-life extended biotherapeutics

INTRODUCTION

Many of the biotherapeutics approved or under development suffer from a short half-life necessitating frequent applications in order to maintain a therapeutic concentration over an extended period of time. The implementation of half-life extension strategies allows the generation of long-lasting therapeutics with improved pharmacokinetic and pharmacodynamic properties.

AREAS COVERED

This review gives an overview of the different half-life extension strategies developed over the past years and their application to generate next-generation biotherapeutics. It focuses on srategies already used in approved drugs and drugs that are in clinical development. These strategies include those aimed at increasing the hydrodynamic radius of the biotherapeutic and strategies which further implement recycling by the neonatal Fc receptor (FcRn).

EXPERT OPINION

Half-life extension strategies have become an integral part of development for many biotherapeutics. A diverse set of these strategies is available for the fine-tuning of half-life and adaption to the intended treatment modality and disease. Currently, half-life extension is dominated by strategies utilizing albumin binding or fusion, fusion to an immunoglobulin Fc region and PEGylation. However, a variety of alternative strategies, such as fusion of flexible polypeptide chains as PEG mimetic substitute, have reached advanced stages and offer further alternatives for half-life extension.

Early versus delayed erythropoietin for the anaemia of end-stage kidney disease

BACKGROUND

Anaemia is a common complication in people with chronic kidney disease (CKD) and mainly develops as a consequence of relative erythropoietin (EPO) deficiency. Anaemia develops early in the course of disease and peaks among people with end-stage kidney disease (ESKD). Many types of EPO - also called erythropoiesis-stimulating agents (ESAs) - are used to treat anaemia in people with ESKD.ESAs have changed treatment of severe anaemia among people with CKD by relieving symptoms and avoiding complications associated with blood transfusion. However, no benefits have been found in relation to mortality rates and non-cardiac fatal events, except quality of life. Moreover, a relationship between ESA use and increased cardiovascular morbidity and mortality in patients with CKD has been reported in studies with fully correcting anaemia comparing with partial anaemia correction. Until 2012, guidelines recommended commencing ESA treatment when haemoglobin was less than 11 g/dL; the current recommendation is EPO commencement when haemoglobin is between 9 and 10 g/dL. However, advantages in commencing therapy when haemoglobin levels are greater than 10 g/dL but less than 11 g/dL remain unknown, especially among older people whose life expectancy is limited, but in whom EPO therapy may improve quality of life.

OBJECTIVES

To assess the clinical benefits and harms of early versus delayed EPO for anaemia in patients with ESKD undergoing haemodialysis or peritoneal dialysis

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register to 8 July 2015 through contact with the Trials' Search Co-ordinator using search terms relevant to this review.

SELECTION CRITERIA

We planned to include randomised controlled trials (RCTs) and quasi-RCTs evaluating at the clinical benefits and harms of early versus delayed EPO for anaemia in patients with ESKD undergoing haemodialysis or peritoneal dialysis. Studies comparing EPO with another EPO, placebo or no treatment were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

It was planned that two authors would independently extract data from included studies and assess risk of bias using the Cochrane risk of bias tool. For dichotomous outcomes (all-cause mortality, cardiovascular mortality, overall myocardial infarction, overall stroke, vascular access thrombosis, adverse effects of treatment, transfusion), we planned to use the risk ratio (RR) with 95% confidence intervals (CI). We planned to calculate the mean difference (MD) and CI 95% for continuous data (haemoglobin level) and the standardised mean difference (SMD) with CI 95% for quality of life if different scales had been used.

MAIN RESULTS

Literature searches yielded 1910 records, of these 1534 were screened after duplicates removed, of which 1376 were excluded following title and abstract assessment. We assessed 158 full text records and identified 18 studies (66 records) that were potentially eligible for inclusion. However, none matched our inclusion criteria and were excluded.

AUTHORS' CONCLUSIONS

We found no evidence to assess the benefits and harms of early versus delayed EPO for the anaemia of ESKD.

Erythropoietin and diabetes mellitus

Erythropoietin (EPO) is a 30.4 kDa growth factor and cytokine that governs cell proliferation, immune modulation, metabolic homeostasis, vascular function, and cytoprotection. EPO is under investigation for the treatment of variety of diseases, but appears especially suited for the treatment of disorders of metabolism that include diabetes mellitus (DM). DM and the complications of this disease impact a significant portion of the global population leading to disability and death with currently limited therapeutic options. In addition to its utility for the treatment of anemia, EPO can improve cardiac function, reduce fatigue, and improve cognition in patients with DM as well as regulate cellular energy metabolism, obesity, tissue repair and regeneration, apoptosis, and autophagy in experimental models of DM. Yet, EPO can have adverse effects that involve the vasculature system and unchecked cellular proliferation. Critical to the cytoprotective capacity and the potential for a positive clinical outcome with EPO are the control of signal transduction pathways that include protein kinase B, the mechanistic target of rapamycin, Wnt signaling, mammalian forkhead transcription factors of the O class, silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae), and AMP activated protein kinase. Therapeutic strategies that can specifically target and control EPO and its signaling pathways hold great promise for the development of new and effective clinical treatments for DM and the complications of this disorder.

Treatment Options for Primary Autoimmune Hemolytic Anemia: A Short Comprehensive Review

Until now, treatment of primary autoimmune hemolytic anemia of the warm type (wAIHA) is primarily based on immunosuppression. However, many patients do not respond adequately to treatment, and treated patients may develop severe side effects due to uncontrolled, mixed and/or long-lasting immunosuppression. Unfortunately, the newly used therapeutic monoclonal antibodies are unspecific and remain frequently ineffective. Thus, development of a specific therapy for AIHA is necessary. The ideal therapy would be the identification and elimination of the causative origin of autoimmunization and/or the correction or reprogramming of the dysregulated immune components. Blood transfusion is the most rapidly effective measure for patients who develop or may develop hypoxic anemia. Although some effort has been made to guide physicians on how to adequately treat patients with AIHA, a number of individual aspects should be considered prior to treatment. Based on my serological and clinical experience and the analysis of evidence-based studies, we remain far from any optimized therapeutic measures for all AIHA patients. Today, the old standard therapy using controlled steroid administration, with or without azathioprine or cyclophosphamide, is, when complemented with erythropoiesis-stimulating agents, still the most effective therapy in wAIHA. Rituximab or other monoclonal antibodies may be used instead of splenectomy in therapy-refractory patients.

The effect of erythropoiesis-stimulating agents in patients with therapy-refractory autoimmune hemolytic anemia

BACKGROUND

Many patients with autoimmune hemolytic anemia (AIHA) do not respond to standard therapy and/or may develop severe complications which can be of fatal outcome. There is some evidence that erythropoiesis-stimulating agents (ESAs) may be helpful in the management of such patients.

METHODS

We describe the effect of ESAs in 12 new patients with therapy-refractory AIHA (7 of warm type and 5 of cold type) and review 5 previously reported cases. Serological testing was performed using standard methods.

RESULTS

All patients responded well to treatment with ESAs. At least 5 of the 17 patients demonstrated complete recovery, and none of the patients developed significant adverse reactions due to treatment with ESAs.

CONCLUSION

The mechanism by which ESAs improves hemolysis in AIHA is not completely clear. In addition to increased production and prolonged RBC survival, it may inhibit eryptosis (programmed cell death). ESAs represent a new option in the treatment of decompensated and/or refractory AIHA of warm and cold type. However, more information is required to assess which patients can be treated with ESAs.