Red Blood Cell Production Research Articles

Carotid Vessel Wall MRI Findings in Acute Cerebral Infarction Caused by Polycythemia Vera: A Case Report

Polycythemia vera (PV) is a rare myeloproliferative disease that causes elevated absolute red blood cell (RBC) mass due to uncontrolled RBC production. Moreover, this condition has been associated with a high risk of ischemic stroke and large vessel stenosis or occlusion, with many studies reporting cerebral infarction in PV patients. Despite these findings, there have been no reports on the vessel wall MRI (VW-MRI) findings of the narrowed vessels in PV-associated ischemic stroke patients. To the best of our knowledge, this is the first report in English regarding the carotid VW-MRI findings of a 30-year-old male diagnosed with PV after being hospitalized due to stroke.

Role of Exercise Intensity on Th1/Th2 Immune Modulations During the COVID-19 Pandemic.

The COVID-19 pandemic has led to several pioneering scientific discoveries resulting in no effective solutions with the exception of vaccination. Moderate exercise is a significant non-pharmacological strategy, to reduce the infection-related burden of COVID-19, especially in patients who are obese, elderly, and with additional comorbidities. The imbalance of T helper type 1 (Th1) or T helper type 2 (Th2) cells has been well documented among populations who have suffered as a result of the COVID-19 pandemic, and who are at maximum risk of infection and mortality. Moderate and low intensity exercise can benefit persons at risk from the disease and survivors by favorable modulation in Th1/Th2 ratios. Moreover, in COVID-19 patients, mild to moderate intensity aerobic exercise also increases immune system function but high intensity aerobic exercise may have adverse effects on immune responses. In addition, sustained hypoxia in COVID-19 patients has been reported to cause organ failure and cell death. Hypoxic conditions have also been highlighted to be triggered in COVID-19-susceptible individuals and COVID-19 survivors. This suggests that hypoxia inducible factor (HIF 1α) might be an important focus for researchers investigating effective strategies to minimize the effects of the pandemic. Intermittent hypoxic preconditioning (IHP) is a method of exposing subjects to short bouts of moderate hypoxia interspersed with brief periods of normal oxygen concentrations (recovery). This methodology inhibits the production of pro-inflammatory factors, activates HIF-1α to activate target genes, and subsequently leads to a higher production of red blood cells and hemoglobin. This increases angiogenesis and increases oxygen transport capacity. These factors can help alleviate virus induced cardiopulmonary hemodynamic disorders and endothelial dysfunction. Therefore, during the COVID-19 pandemic we propose that populations should engage in low to moderate exercise individually designed, prescribed and specific, that utilizes IHP including pranayama (yoga), swimming and high-altitude hiking exercise. This would be beneficial in affecting HIF-1α to combat the disease and its severity. Therefore, the promotion of certain exercises should be considered by all sections of the population. However, exercise recommendations and prescription for COVID-19 patients should be structured to match individual levels of capability and adaptability.

Erythropoietin exerted neuroprotection against cardiac ischemic/reperfusion injury by ameliorating oxidative stress, mitochondrial dysfunction, microglial activation, apoptosis and necroptosis

Acute cardiac ischemic/reperfusion (I/R) injury not only caused cardiac dysfunction, but also caused the development of brain dysfunction and pathology, including blood brain barrier breakdown, increased brain oxidative stress, brain mitochondrial dysfunction, brain mitochondrial dynamic imbalance, hippocampal dysplasticity, and hippocampal apoptosis. Previous studies demonstrated that erythropoietin (EPO), an important hormone for red blood cell production in response to low oxygen, exerted neuroprotective effect following cerebral ischemic-reperfusion injury. However, the effect of erythropoietin administration on brain pathology in response to cardiac I/R injury have not been investigated. Forty male Wistar rats were divided into five groups (n=8/group) including 1) control group, 2) I/R operation with vehicle (0.9% sodium chloride solution at 15 minutes prior to I/R protocol, as Vehicle), 3) I/R operation with pretreatment (5000 IU/kg at 15 minutes before I/R protocol as PEPO), 4) I/R operation with EPO administration during cardiac ischemia (5000 IU/kg at 15 minutes after left anterior descending (LAD) coronary artery ligation as DEPO), and 5) I/R operation with EPO administration at the onset of reperfusion (5000 IU/kg at the beginning of reperfusion as REPO). Acute cardiac I/R injury increased both peripheral and brain oxidative stress, caused brain mitochondrial dysfunction, increased Alzheimer's related protein, increased microglial activation, developed synaptic dysplasticity, increased apoptotic and necroptotic signaling (p<0.05, Figure 1). Given the EPO prior to I/R operation, but not during and at the onset of reperfusion, decreased both peripheral and brain oxidative stress, attenuated brain mitochondrial dysfunction, and decreased Alzheimer's related protein (p<0.05, Figure 1). Moreover, pretreatment with EPO had better efficacy to preserve microglial morphology and attenuate synaptic dysplasticity compared to given the EPO during and at the onset of reperfusion (p<0.05, Figure 1). Interestingly, administration of EPO at all time points equally decreased apoptotic and necroptotic signaling against cardiac I/R injury (p<0.05, Figure 1). These findings suggest that erythropoietin exert neuroprotection against acute cardiac ischemic/reperfusion injury through decreased oxidative stress, mitochondrial dysfunction, Alzheimer's related protein, microglial hyperactivity, synaptic dysplasticity, apoptosis and necroptosis. The present study provided information contribute to the clinical application of EPO to ameliorate brain pathologies under cardiac I/R condition.

Impact of Anemia on the School Performance of Students at a Public School in Ceará

Anemia is defined as a condition in which hemoglobin levels are below the normal range. Among children and adolescents, iron deficiency is responsible for most cases. Iron is an essential compound for the production of red blood cells and transportation of oxygen, as well as for the integration of the enzymatic systems of different tissues. Patients with iron deficiency anemia may have impaired cognitive, physical and immune development, thus increasing the risk of infections and even death. This is a cross-sectional study to analyze the prevalence of anemia and its impact on school and nutritional performance among elementary school adolescents aged between 10 and 14 years from May 2019 to October 2019.

Pluripotin stimulates the growth of hematopoietic stem cells while suppressing the expansion of bone marrow mesenchymal stem cells and fibroblasts

Hematopoietic stem cells (HSCs) are essential in the production and maintenance of red blood and immune cells. Small molecules that target HSC modulators may aid in the proliferation and expansion of HSCs. To that end, we investigated the effect of two small molecules on HSC expansion: pluripotin (an ERK1 and RasGAP inhibitor) and CHIR-99021 (a GSK-3 inhibitor). After 7 days of treatment, both Pluripotin and CHIR-99021 resulted in a 3-fold increase in the murine pool of HSCs in a dose-dependent manner. Furthermore, we looked into the effect of Pluripotin on the ex vivo expansion of human umbilical cord blood and bone marrow mononuclear cells. Pluripotin treatment, in particular, increased human CD34+ and ALDHbr HSC content up to threefold when compared to the control. Furthermore, Pluripotin treatment increased the number of human CD133+ HSC cells by a factor of five. Intriguingly, Pluripotin treatment reduces bone marrow-derived mesenchymal stem cell (MSC) proliferation and fibroblast growth while having no effect on adipose-derived MSCs. CHIR-99021 treatment had no effect on MSC or fibroblast proliferation. In conclusion, pluripotin-induced stem cell expansion is unique to HSCs and can be used to expand HSCs while suppressing unwanted fibroblast or MSC growth in primary ex vivo cultures.

Impact of Blinatumomab Treatment on Bone Marrow Function in Patients with Relapsed/Refractory B-Cell Precursor Acute Lymphoblastic Leukemia.

Simple SummaryMyelosuppression is a side effect of chemotherapy, in which the production of red and white blood cells and platelets is reduced, increasing risk of infections. Blinatumomab, a bispecific T-cell engager (BiTE®) molecule, is a novel anticancer drug that kills acute lymphoblastic leukemia (ALL) cells while sparing majority of the normal bone marrow cells. Results from our study, which compared the effects of blinatumomab treatment with chemotherapy on bone marrow function in a large number of patients with ALL, indicated that the decrease in blood cell counts was more severe and lasted longer after chemotherapy compared with blinatumomab treatment, in which the effects were transient. Survival in patients treated with blinatumomab achieving complete remission was more similar between those with incomplete recovery of blood cell counts versus those with complete blood cell counts than the corresponding survival outcomes seen with chemotherapy. In conclusion, blinatumomab treatment caused transient myelosuppression when compared with chemotherapy.Association of blinatumomab treatment with myelosuppression was examined in this study. Peripheral blood counts were assessed prior to, during, and after blinatumomab treatment in patients with relapsed/refractory Philadelphia chromosome-negative (Ph−) B-cell precursor (BCP) acute lymphoblastic leukemia (ALL; n = 267) and Ph+ BCP-ALL (n = 45) from the TOWER and ALCANTARA studies, respectively, or chemotherapy in patients with Ph− BCP-ALL (n = 109) from the TOWER study; all the patients with relapsed/refractory BCP-ALL and responders achieving complete remission (CR) or CR with partial/incomplete hematological recovery (CRh/CRi) were evaluated. Event-free survival (EFS) and overall survival (OS) were assessed in patients achieving CR and CRh/CRi. Median leukocyte, neutrophil, and platelet counts increased during two blinatumomab cycles but remained low longer after chemotherapy. Among the responders, there was a trend that a greater proportion of patients achieved CR with blinatumomab (Ph−, 76.5%; Ph+, 77.8%) versus with chemotherapy (Ph−, 63.6%). In the TOWER study, the survival prognosis for patients achieving CRh/CRi versus CR with blinatumomab was more similar (median OS, 11.9 (95% CI, 3.9–not estimable (NE)) vs. 15.0 (95% CI, 10.4–NE) months, p = 0.062) than with chemotherapy (5.2 (95% CI, 1.6–NE) vs. 18.9 (95% CI, 9.3–NE) months, p = 0.013). Blinatumomab treatment, with only temporary and transient myelosuppression, resulted in a greater survival benefit than chemotherapy.

Luspatercept Redistributes Body Iron to the Liver in Transfusion-Dependent-Thalassemia (TDT) during Erythropoietic Response

Luspatercept Redistributes Body Iron to the Liver in Transfusion-Dependent-Thalassemia (TDT) during Erythropoietic Response

Title: Efficacy and Safety of Ferric Derisomaltose for Treatment of Anemia in Chronic Kidney Disease Patients: A Systematic Review

BackgroundAnemia in chronic kidney disease (CKD) patients develop primarily due to iron and erythropoietin deficiency, factors contributing to this include uremia induced inhibition of erythropoiesis, shortened red cell survival and nutritional deficiency. Erythropoietin stimulating agents (ESA) used in CKD increases iron demand for the production of new red blood cells (RBCs). Oral iron does not provide a reliable route to meet the demand of the iron required and poses the risk of side effects. The intravenous formulation provides the fastest route, although multiple intravenous formulations are available they require multiple dosing and still carry a risk of an adverse event. Ferric derisomaltose/iron isomaltoside (IIM) is an intravenous formulation of iron recently approved by the Food and drug administration (FDA) for patients intolerant to oral iron and non-dialysis dependent CKD patients. FDI is administered in high dose usually in a single administration. In this systematic review, we evaluated the published literature for the efficacy and safety of ferric derisomaltose in both dialysis-dependent and dialysis independent patients.Material/MethodsA literature search was done using the following databases: PubMed, Cochrane, Embase, Clinical trials.gov, and Web of Science. The search was completed without using any filter and we used the Mesh Terms for “anemia”, “iron deficiency anemia” “chronic kidney disease” and “ferric compounds”. Total of 316 which were further screened and we included 2 trials, and 2 prospective studies. Case reports, preclinical trials, meta-analyses, and review articles were excluded. We followed the PRISMA guidelines for literature search and selection of studies. We only included the trial studies that were completed. We excluded the studies that did not report efficacy and safety.ResultsIn total, amongst the four studies, 1558 CKD patients received ferric derisomaltose in a single dose. Patients in all stages of CKD were studied but most patients were between stages I to stage III CKD, stage IV and V(dialysis-dependent) were studied by Kalra et al (2020). A single dose of 1000 mg/dl of IIM, was administered intravenously. The mean pre-treatment haemoglobin level varied from 9.6g/dl to 10.6 g/dl. The mean serum ferritin ranged from 82.4 µg/L to 161.9 µg/L and the mean transferrin saturation ranged in patients from 15.8% to 18.51%. IIM receiving patients were compared with iron sucrose receiving patients by Bhandari et al, and oral iron by Kalra et al (2015). The remaining two studies compared single IIM with multiple IIM dosages. The results are summarised in the table below.Efficacy: The increase in haemoglobin ranged between 0.9 g/dL to 6.58 g/dL from baseline measured at 8 weeks. At the same time, serum ferritin showed an increase in baseline serum ferritin from 104 µg/L to 277 µg/L and transferrin saturation (TSAT) increased in the range of 5.3%-11.4 %. All markers of iron deficiency showed significant improvement. It achieved a greater Hb response irrespective of ESA treatment in both haemodialysis dependent and non-dependent patients. In the comparison group by Bhandari et al, iron sucrose receiving patients also had similar efficacy as IIM. On the other hand, those receiving oral iron in the study by Kalra et al (2015) had much poorer efficacy as compared to IIMSafety: Severe adverse effect was seen in a total of 10 (0.6%) patients who developed hypersensitivity reaction, acute myocardial infarction and injection site-related adverse effects with hypersensitivity being the most common. 15 (0.9%) patients discontinued the treatment. 21 (1.3%) died, and the death was attributed to end-stage renal disease.ConclusionFerric derisomaltose is an effective parenteral iron therapy to treat iron deficiency when compared to oral iron therapy, however, its efficacy is very similar to other parenteral iron formulations. In terms of safety, being used as a single dose it relatively has lesser adverse events but can seldom lead to discontinuation of the drug. This drug can be recommended for iron therapy especially considering single-dose administration but more studies need to be carried out in comparison to other parenteral formulations to further clarify its efficacy in dialysis-dependent CKD patients. [Display omitted] DisclosuresAnwer: BMS / Celgene: Honoraria, Research Funding; GlaxoSmithKline: Research Funding; Janssen pharmaceutical: Honoraria, Research Funding; Allogene Therapeutics: Research Funding.

Tfr2 Genetic Deletion Makes Transfusion-Independent a Murine Model of Transfusion-Dependent β-Thalassemia

β-thalassemia is an autosomal recessive disorder due to mutations in the β-globin gene, that leads to defective production of hemoglobin (Hb) and red blood cells (RBC). The main features of the disease are anemia, ineffective erythropoiesis and iron overload. Patients affected by the most severe form of β-thalassemia are transfusion-dependent (TDT) and require lifelong blood transfusions and iron chelation, symptomatic treatments that affect the quality of life. The only curative option, unfortunately limited by the insufficient number of HLA-matched donors, is allogenic bone marrow (BM) transplantation. Other recently approved treatments (i.e. Luspatercept and gene therapy) are only partially effective and/or suitable for selected patients. Thus, the identification of novel therapeutic approaches is a clinical need.Transferrin receptor 2 (TFR2) contributes to the transcriptional activation of hepcidin, the master regulator of iron homeostasis, in the liver and is a brake of Erythropoietin signaling in erythroid cells, thus balancing RBC production and iron availability. We have recently proved that BM Tfr2 deletion enhances erythropoiesis in wild-type mice (Nai et al., Blood 2015) and ameliorates anemia in non-TDT mice models, both alone (Artuso et al., Blood 2018) and in combination with iron-restricting agents (Casu, Pettinato et al., Blood 2020).Here we aim at investigating whether Tfr2 targeting might be beneficial also for TDT. To this purpose we generated TDT mice (Hbb th1/th2; Casu et al., Haematologica 2020) with heterozygous (Tfr2 BMhetero/Hbb th1/th2) and homozygous (Tfr2 BMKO/Hbb th1/th2) BM Tfr2 deletion by transplantation of Hbb th1/th2, Tfr2-hetero/Hbb th1/th2 and Tfr2-ko/Hbb th1/th2 fetal liver cells (FLT) from day E14.5 embryos into lethally irradiated wild-type mice. BM Tfr2 deficient mice have increased RBC count and Hb levels and decreased percentage of reticulocytes with a gene dosage effect 8 weeks after FLT, before the onset of transfusion-dependance. At this time-point, complete BM Tfr2 deletion ameliorates ineffective erythropoiesis, decreasing the percentage of polychromatic erythroblasts and increasing orthochromatic erythroblasts and mature RBCs both in the BM and in the spleen. The improved anemia was also accompanied by a partial correction of two debilitating TDT complications, iron overload and cardiomegaly.The beneficial effect of Tfr2 deletion was maintained over time. Indeed, Hbb th1/th2 mice became transfusion-dependent 14 weeks after FLT, when Hb levels drop below 5.5 g/dL, requiring transfusions of an average 108.75±56.87μL of blood/animal/week. On the contrary, animals with both heterozygous and homozygous BM Tfr2 deletion are still non-transfusion-dependent at 20 weeks, maintaining Hb levels above 7 and 9 g/dL respectively.Overall, our results prove that, despite the persistence of the genetic defect, hematopoietic Tfr2 deletion ameliorates anemia, ineffective erythropoiesis and secondary complications also in the most severe form of β-thalassemia. This improvement is associated to a substantial increase in transfusion-free survival of both Tfr2 BMhetero/Hbb th1/th2 and Tfr2 BMKO/Hbb th1/th2 mice, which are transfusion-independent 6 weeks after the time of blood transfusion requirement in Hbb th1/th2animals. The difference of blood transfusions needs will be evaluated over time for at least 10 additional weeks.Our findings demonstrate that TFR2 targeting represents a new promising therapeutic opportunity for the management of β-thalassemia, worth to be tested both as a monotherapy and in association with available treatments. DisclosuresRivella: Incyte: Consultancy; MeiraGTx: Consultancy, Membership on an entity's Board of Directors or advisory committees; Forma Theraputics: Consultancy; Keros Therapeutics: Consultancy, Membership on an entity's Board of Directors or advisory committees; Disc Medicine: Consultancy, Membership on an entity's Board of Directors or advisory committees; Ionis Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene Corporation: Consultancy.

Functional Requirements of a Samd14-Capping Protein Interaction in Stress Erythropoiesis

Stress erythropoiesis describes the process of accelerating red blood cell (RBC) production in anemia. Among a number of important mediators of stress erythropoiesis, paracrine signals - involving cooperation between SCF/c-Kit signaling and other signaling inputs - are required for the activation/function of stress erythroid progenitors. Whereas many critical factors required to drive erythropoiesis in normal physiological conditions have been described, whether distinct mechanisms control developmental, steady-state, and stress erythropoiesis in anemia is poorly understood. Our prior work revealed that the Sterile Alpha Motif (SAM) Domain 14 (Samd14) gene is transcriptionally upregulated in a model of acute hemolytic anemia induced by the RBC-lysing chemical phenylhydrazine. Samd14 is regulated by GATA binding transcription factors via an intronic enhancer (Samd14-Enh). In a mouse knockout of Samd14-Enh (Samd14-Enh -/-), we established that the Samd14-Enh is dispensable for steady-state erythropoiesis but is required for recovery from severe hemolytic anemia. Samd14 promotes c-Kit signaling in vivo and ex vivo, and the SAM domain of Samd14 facilitates c-Kit-mediated cellular signaling and stress progenitor activity. In addition, the Samd14 SAM domain is functionally distinct from closely related SAM domains, which demonstrates a unique role for this SAM domain in stress signaling and cell survival. In our working model, Samd14-Enh is part of an ensemble of anemia-responsive enhancers which promote stress erythroid progenitor activity. However, the mechanism underlying Samd14's role in stress erythropoiesis is unknown.To identify potential Samd14-interacting proteins that mediate its function, we performed immunoprecipitation-mass spectrometry on the Samd14 protein. We found that Samd14 interacted with α- and β heterodimers of the F-actin capping protein (CP) complex independent of the SAM domain. CP binds to actin during filament assembly/disassembly and plays a role in cell morphology, migration, and signaling. Deleting a 17 amino acid sequence near the N-terminus of Samd14 disrupted the Samd14-CP interaction. However, mutating the canonical RxR of the CP interaction (CPI) motif, which is required for CP-binding in other proteins, does not abrogate the Samd14-CP interaction. Moreover, replacing this sequence with the canonical CPI domain of CKIP-1 completely disrupts the interaction, indicating that other sequence features are required to maintain the Samd14-CP complex. Ex vivo knockdown of the β-subunit of CP (CPβ), which disrupts the integrity of the CP complex, decreased the percentage of early erythroid precursors (p<0.0001) and decreased (3-fold) progenitor activity as measured by colony formation assays (similar to knockdown of Samd14). Taken together, these data indicate that Samd14 interacts with CP via a unique CP binding (CPB) domain, and that the CP complex coordinates erythroid differentiation in stress erythroid progenitors.To test the function of the Samd14-CP complex, we designed an ex vivo genetic complementation assay to express Samd14 lacking the CPB-domain (Samd14∆CPB) in stress erythroid progenitors isolated from anemic Samd14-Enh -/- mice. Phospho-AKT (Ser473) and phospho-ERK (Thr202/Tyr204) levels in Samd14∆CPB were, respectively, 2.2 fold (p=0.007) and ~7 fold (n=3) lower than wild type Samd14 expressing cells, 5 min post SCF stimulation. Relative to Samd14, Samd14∆CPB expression reduced burst forming unit-erythroid (BFU-E) (2.0 fold) and colony forming unit-erythroid (CFU-E) (1.5 fold). These results revealed that the Samd14-CP interaction is a determinant of BFU-E and CFU-E progenitor cell levels and function. Remarkably, as the requirement of the CPB domain in BFU-E and CFU-E progenitors is distinct from the Samd14-SAM domain (which promotes BFU-E but not CFU-E), the function of Samd14 in these two cell types may differ. Ongoing studies will examine whether the function of Samd14 extends beyond SCF/c-Kit signaling and establish cell type-dependent functions of Samd14 and Samd14-interacting proteins. Given the critical importance of c-Kit signaling in hematopoiesis, the role of Samd14 in mediating pathway activation, and our discovery implicating the capping protein complex in erythropoiesis, it is worth considering the pathological implications of this mechanism in acute/chronic anemia and leukemia. DisclosuresNo relevant conflicts of interest to declare.

Erythroid Chimerism Measurement As a Predictive Tool of Bone Marrow Transplantation Outcome in Sickle Cell Disease

Allogeneic bone marrow transplantation (BMT) is the only curative treatment available for sickle cell disease (SCD). The effectiveness of the treatment is primarily assessed by the chimerism rate, which is the fraction of cells derived from the donor's hematopoietic stem cells (HSCs) relative to the recipient's cells. New less toxic conditioning agents, described as reduced, nonmyeloablative (as opposed to myeloablative conditioning agents) are now used for BMT with sibling donors. Moreover, most sibling donors are sickle cell trait carriers (heterozygous A/S genotype). In the absence of a test performed on erythroid cells, the rate of chimerism is currently assessed either on different subpopulations of myeloid cells by molecular biology techniques or on hemoglobin measurement by chromatography (HPLC). However, the percentage of myeloid chimerism is rarely representative of the percentage of erythroid chimerism in these patients and HPLC cannot allow analysis at the single cell level.An easy-to-implement method for accurate measurement of fetal hemoglobin (HbF) content in individualized red blood cells (RBCs) has recently been developed (Hebert, et. al, AJH 2020). This method relies on flow cytometry for cell individualization and intracellular labeling of HbF with a fluorescent monoclonal antibody for quantification. Based on the same approach, we propose the use of monoclonal antibodies directed against adult hemoglobins (HbA0 and HbA2) or hemoglobin S (HbS). This strategy allows to discriminate, from a blood sample, the different RBC subpopulations coming from either the recipient or the donor, or from the transfusion associated with this procedure, thus allowing us to precisely determine the rates of erythroid chimerism in patients.As a proof of concept, we show here the evaluation of the percentage of erythroid chimerism during a longitudinal follow-up performed on 3 patients with SCD (P1 - 18 months, P2 - 4 months, and P3 - 4 months). The 3 patients received allogeneic BMT from a sibling A/S donor following nonmyeloablative conditioning consisting of the administration of an anti-CD52 antibody associated with radiotherapy (300 cGy TBI - total-body irradiation). We observed for P1 and P2 donor erythroid chimerism >90% and >95%, 1 and 2 months after BMT, respectively (measured after exclusion of transfused RBCs). These results are in accordance with the presence of most RBCs HbA- and HbS-positive, as determined by flow cytometry. In addition, the analysis of the reticulocyte (retic) subpopulations (CD71-positive cells) of these patients provides precise information on the RBC production of the bone marrow following transplantation. Retic donor chimerism levels were >99% for both P1 and P2, 1 month after BMT procedure. P1 and P2 showed stable donor reticulocyte and donor erythroid chimerism levels during the follow-up. On the contrary, P3 presented a different response with 43%, 41% and 5% donor erythroid chimerism 1, 2 and 3 months after BMT, respectively. Retrospectively, this bad response in P3 would have been predicted by low donor reticulocyte chimerism levels (5%, 6% and 0.5% at 1, 2 and 3 months after BMT, respectively). Our erythroid specific chimerism results were also compared to the assessment of chimerism performed on either total white blood cells (WBCs) or lineage specific subpopulations after sorting. Over 18 months after BMT in P1, the correlation between retic chimerism and total WBCs or T lymphocytes (CD3-positive cells) chimerism were not statistically significant (P = 1 and P = 0.833, respectively - Spearman test) (Figure 1).This new tool to monitor BMT outcome to treat SCD shows great precision and potentially a stronger predictive capability than total WBCs or lineage specific chimerism assessed by molecular biology. Our results highlight the importance of analyzing reticulocyte population to better assess BMT efficacy and predict the outcome a few days after the transplant. Its use could also be considered in the context of the various gene therapy strategies currently under development using modified β-globin gene addition or direct mutation correction through CRISPR/Cas9 and homologous recombination system. [Display omitted] DisclosuresBencheikh: Innovhem: Current Employment. Bartolucci: Innovhem: Current holder of individual stocks in a privately-held company.

Regulation of Fetal Hemoglobin Expression By the VHL-HIF1α Oxygen Sensing System

Defining the mechanisms that control the perinatal switch from γ-globin (HBG1 and HBG2) to β-globin (HBB) gene expression in human red blood cells (RBCs) has informed novel approaches to reactivate fetal hemoglobin (HbF, α2γ2) therapeutically for sickle cell disease and β-thalassemia. However, one longstanding unsolved problem is to explain how HbF becomes elevated in conditions such as blood loss, hypoxia and hemolysis. These conditions are associated with accelerated RBC production, also referred to as stress erythropoiesis, driven by activation of hypoxia-inducible factor (HIF) via a canonical O 2 sensing pathway. At high O 2 levels (“normoxia”), O 2-dependent prolyl hydroxylase domain (PHD) enzymes hydroxylate HIFα, thereby targeting it for ubiquitination by the von Hippel-Lindau (VHL) E3 ubiquitin ligase complex, followed by proteasomal degradation. At low O 2 tension (hypoxia), PHD activity is reduced, causing HIF1α to accumulate, dimerize with constitutively expressed HIF1β, and bind hypoxia response elements (HREs) to activate a broad array of genes that facilitate hypoxic adaptation. We identified VHL and HIF1α, as negative and positive regulators of HbF expression, respectively.Disruption of the VHL gene in CD34 + hematopoietic stem and progenitor cells (HSPCs) by transfection with ribonucleoprotein (RNP) consisting of Cas9 and VHL-targeting guide RNA increased HbF expression from 7.5% ±1.2% in control cells to 30.9% ± 4.8% (mean ± SD, P<0.0001) in RBC progeny generated by in vitro differentiation. Similarly, γ-globin mRNA was induced by 5 -fold after disruption of VHL in HUDEP-2 cells, an immortalized erythroid line that expresses mainly adult hemoglobin (HbA, α2/β2). Mass spectrometry and transcriptome analysis of VHL-disrupted CD34 + HSPCs revealed increased HIF1α protein expression with no change in the corresponding mRNA. Inhibition of HIF1A mRNA by RNA interference suppressed γ-globin induction in VHL-/- HUDEP-2 clones and in RBCs generated from VHL RNP-treated CD34 + cells, indicating VHL knockout induced HbF through HIF1α protein accumulation. CUT&RUN analysis of VHL-depleted erythroblasts revealed HIF1α/HIF1β heterodimer occupancy at BGLT3, a long-noncoding RNA locus approximately 2.7kb 3' of HBG1. The HIF1α-bound BGLT3 locus contains two canonical HREs (ACGTG) separated by 13 bp. Disruption of each HRE motif in VHL-/- HUDEP-2 cells by base editing caused additive reductions in BGLT3 HIF1α occupancy and γ-globin expression. Mechanistically, VHL depletion caused the accumulation of HIFα/β heterodimers at BGLT3, recruitment of the transcriptional activators GATA1 and P300, and targeted chromatin accessibility to establish the active enhancer mark H3K27ac. These changes were accompanied by altered chromosome conformation to favor long-range interactions between the γ-globin loci (HBG1 and HBG2) and the locus control region, a powerful upstream enhancer. Treatment of healthy donor CD34 + HSPCs-derived erythroblasts with the clinically approved PHD inhibitor FG-4592 (Roxadustat) caused HbF to increase from 4.76%±1.22% at baseline to 12.86 ± 2.40% (mean ± SD in 3 biological replicates, P<0.01). Treatment of the same erythroblasts with FG-4592 and hydroxyurea, a widely used SCD drug that acts partly by inducing HbF, caused HbF to increase from 4.76% ± 1.22% at baseline to 24.1% ± 5.3% (mean ± SD in 3 biological replicates, P<0.01), indicating an additive effect. Our findings link developmental globin gene regulation with O 2 sensing, provide a mechanism for HbF induction during stress erythropoiesis, and identify a novel therapeutic approach for β-hemoglobinopathies. DisclosuresBlobel: Pfizer: Consultancy; Fulcrum Therapeutics, Inc.: Consultancy. Weiss: Beam Therapeutics: Current holder of stock options in a privately-held company; Forma Therapeutics: Consultancy; Cellarity Inc.: Consultancy; Novartis: Consultancy.

From the Literature

From the Literature

Heritable disorders of oxygen sensing.

Hypoxia-inducible factors (HIFs) activate gene transcription in response to reduced O2 availability and play critical roles in development, physiology, and disease pathogenesis. Mutations that dysregulate HIF activity are the genetic basis for tumor predisposition in the von Hippel-Lindau syndrome and excess red blood cell production in hereditary erythrocytosis.

Nurses' Knowledge and Practice in the Care of Anemia during Pregnancy

Anemia isn’t single disease but condition. Like fever, with many possible causes and many forms it can occur of blood loss, destruction of red blood cell or insufficient red blood cell production. This was study aimed to assess nurses’ knowledge and practice regard care of anemia during pregnancy at Alsaudi hospital during period from March to May (2020). The sample size consisted of (20) available nurses in antenatal unite during study period. The data collected by using questionnaire and checklist designed for purpose of study and analyzed using statistical package for social sciences (SPSS). The result showed that 60% of the study sample their age less than 30 years while of the study 95% female. Majority of study sample 70% have master degree and 20% have diploma. Regarding knowledge of anemia disease if found that (60%, 65%, 55%). Regard nursing care to prevent form infection 45% of nurse’s poor knowledge. In nursing management of mother with severe anemia it was found 40% of study sample lack of knowledge. 25%of study sample didn’t know about prevention of anemia and who give advice to the mother. The study group has little knowledge of disease and its impact. The study recommends that nurses should be trained well on competent level of practice regard care of mother.

Role of Hepcidin as a biomarker for iron status in patients on regular hemodialysis

Abstract Background The etiology of anemia in End Stage Renal Disease is multifactorial. Importantly, ESRD patients also have several abnormalities in systemic homeostasis of iron, an essential component in the production of red blood cells. Aim of the Work to assess hepcidin level in negative virology End Stage Renal Disease patients &amp; its relation to iron level and erythropoiesis. Patients and Methods This study was conducted on 45 patients who are stage V chronic kidney disease on regular haemodialysis. Ten age and sex matched controls were included in the study. The study included 29 (64.4%) males and 16 (35.6%) females; their mean age was 53.40± 11.56 years. The prevalence of diabetes among the studied cases was 17.8%, while that of hypertensive was 42.2%. Mean of serum iron level was 64.23±19.53. Mean of TIBC was 409.96±67.85. Mean of Ferritin level 394.55±139.23 and mean of Hepcidin level was 218.51±127. Results Significant negative correlation between Hepcidin level and the Hemoglobin level, and highly significant positive correlation between Hepcidin level and serum Ferritin. Hepcidin up-regulation in the setting of CKD, with subsequent increased serum levels, results in impaired iron absorption from the intestine and decreased iron release from body storage sites. Ultimately, in the setting of such elevated levels, a state of functional iron deficiency may develop and lead to anemia due to iron-restricted erythropoiesis. Conclusion Based on current evidence, it seems likely that hepcidin represents a potentially modifiable mediator of anemia of CKD and is thus a potential target for future anemia therapy.

Effect of moringa leaf meal and season on blood and hormonal profile of the pearl guinea fowl (Numida meleagris)

This study was undertaken to determine the effect of moringa leaf meal and season on blood and hormonal profile of the Pearl Guinea fowl (Numida meleagris) in the Middle belt of Ghana. Thirty-two (32) males and one hundred and twenty-eight (128) female Pearl Guinea fowls aged one-day-old were used for the study. A 3 x 4 factorial experimental design was used for the experiment. Data collected were analyzed using General Linear Model (GLM) procedure of Statistical Analysis System (SAS for Windows, version 7) and means were separated by the probability of difference (PDIFF) procedure of SAS (2008). Mean cell volume was highest (175.39 fl) among Guinea fowls fed with diet containing 12 % moringa leaf meal level. Guinea fowls fed with diet containing 15 % moringa leaf meal had the highest (3.44 x1012/L) red blood cells production. Eosinophil level was highest (3.95 x1012/L) among Guinea fowls fed with diet containing 9 % moringa leaf meal. Birds fed with the moringa diets recorded the highest (P= 0.022) WBC values as compared to the control diet. Triglycerides, high density lipoprotein and low-density lipoprotein levels increased (P&lt;0.05) with increasing levels of dietary moringa leaf meal in the diet. The highest (P= 0.0025) level of progesterone was observed among birds fed with diet containing 12 and 15 % moringa leaf meal inclusion levels. The level of sodium was highest (166.69 nmol/l) among Guinea fowls fed with diet containing 12 % moringa leaf meal. The major and minor rainy seasons recorded the highest (P&lt;0.05) mean cell hemoglobin, red blood cells, albumin and oestrogen levels. Platelets, follicle stimulating hormone, luteinizing hormone, prolactin and chlorine levels were highest (P&lt;0.05) in the dry season while basophil level was highest in the major rainy season. Cholesterol, triglycerides, high density lipoprotein, low density lipoprotein and potassium levels were highest (P&lt;0.05) in the major rainy season. This study concludes that feeding Guinea fowls with moringa leaf meal had positive effect on some haematological, biochemical and hormonal parameters.

A Spatiotemporal Microenvironment Model to Improve Design of a Three-Dimensional Bioreactor for Red Cell Production.

Cellular microenvironments provide stimuli, including paracrine and autocrine growth factors and physicochemical cues, which support efficient in vivo cell production unmatched by current in vitro biomanufacturing platforms. While three-dimensional (3D) culture systems aim to recapitulate niche architecture and function of the target tissue/organ, they are limited in accessing spatiotemporal information to evaluate and optimize in situ cell/tissue process development. Herein, a mathematical modeling framework is parameterized by single-cell phenotypic imaging and multiplexed biochemical assays to simulate the nonuniform tissue distribution of nutrients/metabolites and growth factors in cell niche environments. This model is applied to a bone marrow mimicry 3D perfusion bioreactor containing dense stromal and hematopoietic tissue with limited red blood cell (RBC) egress. The model characterized an imbalance between endogenous cytokine production and nutrient starvation within the microenvironmental niches and recommended increased cell inoculum density and enhanced medium exchange, guiding the development of a miniaturized prototype bioreactor. The second-generation prototype improved the distribution of nutrients and growth factors and supported a 50-fold increase in RBC production efficiency. This image-informed bioprocess modeling framework leverages spatiotemporal niche information to enhance biochemical factor utilization and improve cell manufacturing in 3D systems. Impact statement Three-dimensional (3D) culture systems are becoming increasingly important because they recapitulate the architecture and, consequently, physiological function of the target tissue/organ. Design and optimization of these 3D biomanufacturing platforms require evaluation of in situ spatiotemporal information. We have developed an integrated experimental-computational framework that captures the spatiotemporal distribution of cells, nutrients, and cytokines within a marrow biomimicry perfusion bioreactor. The model simulated biochemical factor utilization and guided the design of an improved second-generation bioreactor that achieved 50-fold increase in RBC production with improved cost efficiency. Such a modeling framework provides an essential platform for the optimization of 3D biomanufacturing systems.

Reticulocyte and Erythrocyte Hemoglobin Parameters for Iron Deficiency and Anemia Diagnostics in Patient Blood Management. A Narrative Review.

Anemia, iron deficiency and other hematinic deficiencies are a major cause of perioperative transfusion needs and are associated with increased morbidity and mortality. Anemia can be caused either by decreased production of hemoglobin or red blood cells or by increased consumption and blood loss. Decreased production can involve anything from erythropoietin or vitamin B12 insufficiency to absolute or functional lack of iron. Thus, to achieve the goal of patient blood management, anemia must be addressed by addressing its causes. The traditional parameters to diagnose anemia, despite offering elaborate options, are not ideally suited to giving a simple overview of the causes of anemia, e.g., iron status for erythropoiesis, especially during the acute phase of inflammation, acute blood loss or iron deficiency. Reticulocyte hemoglobin can thus help to uncover the cause of the anemia and to identify the main factors inhibiting erythropoiesis. Regardless of the cause of anemia, reticulocyte hemoglobin can also quickly track the success of therapy and, together with the regular full blood count it is measured alongside, help in clearing the patient for surgery.

Erythropoietin Non-hematopoietic Tissue Response and Regulation of Metabolism During Diet Induced Obesity.

Erythropoietin (EPO) receptor (EPOR) determines EPO response. High level EPOR on erythroid progenitor cells gives rise to EPO regulated production of red blood cells. Animal models provide evidence for EPO activity in non-hematopoietic tissue mediated by EPOR expression. Beyond erythropoiesis, EPO activity includes neuroprotection in brain ischemia and trauma, endothelial nitric oxide production and cardioprotection, skeletal muscle wound healing, and context dependent bone remodeling affecting bone repair or bone loss. This review highlights examples of EPO protective activity in select non-hematopoietic tissue with emphasis on metabolic response mediated by EPOR expression in fat and brain and sex-specific regulation of fat mass and inflammation associated with diet induced obesity. Endogenous EPO maintains glucose and insulin tolerance and protects against fat mass accumulation and inflammation. Accompanying the increase in erythropoiesis with EPO treatment is improved glucose tolerance and insulin response. During high fat diet feeding, EPO also decreases fat mass accumulation in male mice. The increased white adipose tissue inflammation and macrophage infiltration associated with diet induced obesity are also reduced with EPO treatment with a shift toward an anti-inflammatory state and decreased inflammatory cytokine production. In female mice the protective effect of estrogen against obesity supersedes EPO regulation of fat mass and inflammation, and requires estrogen receptor alpha activity. In brain, EPOR expression in the hypothalamus localizes to proopiomelanocortin neurons in the arcuate nucleus that promotes a lean phenotype. EPO stimulation of proopiomelanocortin neurons increases STAT3 signaling and production of proopiomelanocortin. Cerebral EPO contributes to metabolic response, and elevated brain EPO reduces fat mass and hypothalamus inflammation during diet induced obesity in male mice without affecting EPO stimulated erythropoiesis. Ovariectomy abrogates the sex-specific metabolic response of brain EPO. The sex-dimorphic EPO metabolic response associated with fat mass accumulation and inflammation during diet induced obesity provide evidence for crosstalk between estrogen and EPO in their anti-obesity potential in female mice mediated in part via tissue specific response in brain and white adipose tissue. Endogenous and exogenous EPO response in non-hematopoietic tissue demonstrated in animal models suggests additional activity by which EPO treatment may affect human health beyond increased erythropoiesis.