Evaluation of hepcidin-25/erythroferrone ratio as a potential biomarker for iron utility and erythropoiesis responsiveness to erythropoiesis-stimulating therapy in comparison to immature erythrocyte/reticulocyte parameters in hemodialysis patients.

BACKGROUND: Anemia-associated chronic kidney disease increases in more advanced stages with a subsequent acceleration in renal impairment progressing to end-stage renal disease. Although hepcidin and erythroferrone have been described as novel biomarkers of iron metabolism, there is still an area of ambiguity regarding iron utility in anemia-associated end-stage renal disease. OBJECTIVES: This study aims to determine the correlations between erythropoietin, erythroferrone, and hepcidin-25 in hemodialysis, and to evaluate the clinical utility of the hepcidin-25/erythroferrone ratio as a biomarker of erythropoiesis-stimulating agent effectiveness compared to reticulocyte maturation parameters. METHODS: Serum erythropoietin, erythroferrone, and hepcidin-25 levels in 35 dialysis-dependent patients on a maintenance dose of a short-acting erythropoiesis-stimulating agent were consequently assessed on Days 0, 5, and 7. The erythropoiesis activity was monitored by measuring the increment in reticulocyte maturation parameters. RESULTS: Though the effectiveness of erythropoiesis in these patients was not associated with the hepcidin-25/erythroferrone ratio, it was lower among those with effective erythropoiesis than those with ineffective erythropoiesis. The effective group showed a statistically significant increase in reticulocyte maturation parameters compared to the ineffective group. CONCLUSIONS: The findings show the pathogenesis of iron homeostasis in hemodialysis, the validity of hepcidin-25/erythroferrone ratio as a biomarker of erythropoiesis-stimulating agent effectiveness, and the advantageous monitoring of reticulocyte maturation measures to improve management of anemia-associated chronic kidney disease.

A novel cis-regulatory element regulates αD and αA-globin gene expression in chicken erythroid cells.

Background: Cis-regulatory elements (CREs) play crucial roles in regulating gene expression during erythroid cell differentiation. Genome-wide erythroid-specific CREs have not been characterized in chicken erythroid cells, which is an organism model used to study epigenetic regulation during erythropoiesis. Methods: Analysis of public genome-wide accessibility (ATAC-seq) maps, along with transcription factor (TF) motif analysis, CTCF, and RNA Pol II occupancy, as well as transcriptome analysis in fibroblasts and erythroid HD3 cells, were used to characterize erythroid-specific CREs. An α-globin CRE was identified, and its regulatory activity was validated in vitro and in vivo by luciferase activity and genome-editing assays in HD3 cells, respectively. Additionally, circular chromosome conformation capture (UMI-4C) assays were used to distinguish its role in structuring the α-globin domain in erythroid chicken cells. Results: Erythroid-specific CREs displayed occupancy by erythroid TF binding motifs, CTCF, and RNA Pol II, as well as an association with genes involved in hematopoiesis and cell differentiation. An α-globin CRE, referred to as CRE-2, was identified as exhibiting enhancer activity over αD and αA genes in vitro and in vivo. Induction of terminal erythroid differentiation showed that α-globin CRE-2 is required for the induction of αD and αA. Analysis of TF binding motifs at α-globin CRE-2 shows apparent regulation mediated by GATA-1, YY1, and CTCF binding. Conclusion: Our findings demonstrate that cell-specific CREs constitute a key mechanism that contributes to the fine-tuning gene regulation of erythroid cell differentiation and provide insights into the annotation and characterization of CREs in chicken cells.

Hemoglobina reticulocitaria en el diagnóstico precoz de la anemia por deficiencia de hierro / Reticulocyte hemoglobin in the early diagnosis of iron deficiency anemia / Hemoglobina de reticulócitos no diagnóstico precoce da anemia por deficiência de ferro

La anemia por deficiencia de hierro es un problema prevalente a nivel global que aparece en niños, adolescentes y mujeres en edad fértil, son los más afectados. La hemoglobina reticulocitaria es un nuevo biomarcador prometedor para el diagnóstico temprano. Objetivo. Evaluar la hemoglobina reticulocitaria para el diagnóstico precoz de anemia por deficiencia de hierro. Metodología. Se realizó una revisión sistemática en bases de datos biomédicas como PubMed, Scielo, Researchgate, Base, Cochrane Library y DOAJ; se incluyeron 24 estudios observacionales (2018-2023) sobre el uso de la hemoglobina reticulocitaria en el diagnóstico de anemia por deficiencia de hierro; se extrajeron datos sobre las características de los estudios, los valores de sensibilidad y especificidad de este biomarcador. Resultados. La hemoglobina reticulocitaria presentó una sensibilidad agrupada de 90% y una especificidad de 89,5% en los estudios analizados. También mostró una diferencia de medias significativa de -2,88 (IC 95%: -3,36 a -2,40) entre grupos con y sin anemia por deficiencia de hierro. Se encontró una heterogeneidad sustancial entre los resultados de los diferentes estudios (I2=95%; p<0,00001). Conclusión. La hemoglobina reticulocitaria demostró elevada sensibilidad y especificidad, así como una diferencia significativa entre grupos con y sin la condición, lo que evidencia su utilidad como prueba para la detección temprana de la anemia por deficiencia de hierro.

Iron deficiency anemia is a prevalent global health problem that appears in children, adolescents and women of childbearing age, who are the most affected. Reticulocyte hemoglobin is a promising new biomarker for early diagnosis. Objective. To evaluate reticulocyte hemoglobin for the early diagnosis of iron deficiency anemia. Methodology. A systematic review was conducted searching biomedical databases including PubMed, Scielo, Researchgate, Base, Cochrane Library and DOAJ; 24 observational studies (2018-2023) were included on the use of reticulocyte hemoglobin in the diagnosis of iron deficiency anemia; data were extracted on the characteristics of the studies and the sensitivity and specificity values of this biomarker. Results. Reticulocyte hemoglobin showed a pooled sensitivity of 90% and a specificity of 89.5% in the studies analyzed. It also showed a significant mean difference of -2.88 (95% CI: -3.36 to -2.40) between groups with and without iron deficiency anemia. Substantial heterogeneity was found among the results of the different studies (I2=95%; p<0.00001). Conclusion. Reticulocyte hemoglobin demonstrated high sensitivity and specificity, as well as a significant difference between groups with and without the condition, which shows its usefulness as a test for the early detection of iron deficiency anemia.

A anemia por deficiência de ferro é um problema de saúde global prevalente que aparece em crianças, adolescentes e mulheres em idade fértil, sendo os mais afetados. A hemoglobina reticulocitária é um novo biomarcador promissor para o diagnóstico precoce. Objetivo. Avaliar a hemoglobina reticulocitária para o diagnóstico precoce da anemia por deficiência de ferro. Metodologia. Foi realizada uma revisão sistemática com busca em bases de dados biomédicas incluindo PubMed, Scielo, Researchgate, Base Cochrane Library e DOAJ; foram incluídos 24 estudos observacionais (2018-2023) sobre o uso da hemoglobina reticulocitária no diagnóstico de anemia por deficiência de ferro; foram extraídos dados sobre as características dos estudos e os valores de sensibilidade e especificidade deste biomarcador. Resultados. A hemoglobina reticulocitária apresentou sensibilidade agrupada de 90% e especificidade de 89,5% nos estudos analisados. Também mostrou uma diferença média significativa de -2,88 (IC 95%: -3,36 a -2,40) entre grupos com e sem anemia por deficiência de ferro. Encontrou-se heterogeneidade substancial entre os resultados dos diferentes estudos (I2=95%; p<0,00001). Conclusão. A hemoglobina reticulocitária demonstrou elevada sensibilidade e especificidade, bem como uma diferença significativa entre grupos com e sem a condição, o que evidencia a sua utilidade como teste para a detecção precoce da anemia por deficiência de ferro.

Compressive Myelopathy Caused by Arachnoid Cyst and Extramedullary Hematopoietic Tissue in a Patient with Thalassemia Major / Mielopatia compressiva por cisto aracnóideo e tecido hematopoiético extramedular em paciente portador de talassemia maior

Thalassemias, inherited diseases of hemoglobin synthesis, are characterized by the presence of deficient hemoglobin chains that deposit in red blood cells, inducing hemolytic anemia. Extramedullary hematopoiesis represents a compensatory picture that usually affects the liver, the spleen, and lymph nodes. The involvement of the epidural space with spinal cord compression is extremely rare. Our objective was to describe the case of RMS, 31 years old, male, ß-thalassemia major carrier, admitted with 2-month progressive paraparesis and urinary retention due to medullary compression by extramedullary hematopoietic tissue and thoracic arachnoid cyst, and to discuss therapeutic options. Magnetic resonance imaging (MRI) showed an extensive intraspinal and extramedullary lesion with homogeneous contrast enhancement of T3- T11 in addition to a T1-T3 cystic lesion isointense to cerebrospinal fluid (CSF). After the presumed diagnosis of spinal cord compression by proliferative hematopoietic tissue, a 10-session fractional radiotherapy treatment was immediately performed. After the radiotherapy treatment, the neurological deficits of the patient persisted despite the excellent image response with almost complete disappearance of the intraspinal mass. However, the MRI showed a persistent T1-T3 cystic lesion with significant mass effect on the spinal cord. The patient was submitted to microsurgery for total resection of this cystic lesion. In the postoperative period, the patient improved his sphincter control and motor deficits. Medullary compression by extramedullary epidural hematopoiesis is a rare complication in thalassemic patients and may be treated with surgery and/or radiotherapy. There are successful cases with the exclusive use of radiotherapy, especially in extensive lesions.

As talassemias, desordens hereditárias da formação de hemoglobina, caracterizam-se pela síntese de cadeias deficientes de hemoglobina que se depositam nas hemácias e induzem a anemia hemolítica. A hematopoiese extramedular representa um quadro compensatório que habitualmente afeta o fígado, o baço e linfonodos, podendo também afetar outros tecidos. O envolvimento do espaço epidural com compressão medular é extremamente raro. No presente trabalho, objetivou-se descrever o caso do paciente RMS, 31 anos, sexo masculino, portador de talassemia ß maior, com paraparesia progressiva há 2 meses e retenção urinária devida à compressão medular por tecido hematopoiético extramedular e cisto aracnóideo torácicos, e discutir as opções terapêuticas. Ressonância magnética (RM) evidenciou extensa lesão expansiva intrarraquiana e extramedular com captação homogênea de contraste de T3-T11, além de lesão cística isointensa ao líquor de T1-T3. Devido à extensão da lesão e anemia grave do paciente, foi optado inicialmente pelo tratamento radioterápico fracionado em 10 sessões. Após o tratamento, o paciente manteve os déficits neurológicos apesar da excelente resposta imaginológica, com desaparecimento quase completo da massa intrarraquiana. Contudo, a RM de controle mostrou persistência da lesão cística T1-T3 com efeito de massa importante sobre a medula. O paciente foi submetido a microcirurgia com ressecção completa da lesão cística. No pós-operatório, houve melhora do controle esfincteriano e dos déficits motores. Compressão medular por hematopoiese extramedular epidural é uma complicação rara nos pacientes talassêmicos, e pode ser tratada com cirurgia e/ou radioterapia. Há casos de sucesso com uso de radioterapia exclusiva, especialmente quando as lesões são extensas.

Anemia in canine chronic kidney disease is multifactorial and associated with decreased erythroid precursor cells, gastrointestinal bleeding, and systemic inflammation.

OBJECTIVE: Compare erythropoiesis-related factors between different stages of canine chronic kidney disease (CKD). ANIMALS: 8 healthy adult dogs (controls), and 24 dogs with CKD, equally divided into 3 groups based on International Renal Interest Society-CKD Guidelines (stage 2, 3, and 4) were recruited between December 2012 and December 2014. METHODS: The following were assessed in all dogs and then compared between groups: bone marrow cytology, CBC, reticulocyte count, urinalysis, serum biochemistry, blood pressure, occult gastrointestinal bleeding, and serum concentrations of parathyroid hormone (PTH), erythropoietin, interleukin-1ß, interleukin-3, tumor necrosis factor-α (TNFα), and interferon-γ. RESULTS: Erythropoiesis inducing and suppressing factors and the results of the bone marrow cytology of dogs in stage 2 CKD did not differ from the control group. The presence of reticulocytosis in CKD stage 2 suggests that blood loss or erythrocyte destruction might be contributing to developing anemia. Anemia in dogs with progressive CKD was associated with increasing PTH and TNFα and with elevation of the ratio of myeloid to erythroid precursor cells caused by hypoplasia of the erythroid series. The latter was represented mainly by a decrease in the population of polychromatophilic rubricytes and metarubricytes. CLINICAL RELEVANCE: Increased PTH and TNFα seem to contribute to the reduced percentage of polychromatophilic rubricytes and erythroid population, thereby aggravating the anemia of dogs with advanced CKD. Gastrointestinal blood loss contributes to anemia in all canine CKD stages.

Evaluation of 2D and 3D Erythroid Differentiation Protocols Using Sickle Cell Disease and Healthy Donor Induced Pluripotent Stem Cells.

BACKGROUND: Sickle cell disease (SCD) is a highly prevalent genetic disease caused by a point mutation in the HBB gene, which can lead to chronic hemolytic anemia and vaso-occlusive events. Patient-derived induced pluripotent stem cells (iPSCs) hold promise for the development of novel predictive methods for screening drugs with anti-sickling activity. In this study, we evaluated and compared the efficiency of 2D and 3D erythroid differentiation protocols using a healthy control and SCD-iPSCs. METHODS: iPSCs were subjected to hematopoietic progenitor cell (HSPC) induction, erythroid progenitor cell induction, and terminal erythroid maturation. Differentiation efficiency was confirmed by flow cytometry analysis, colony-forming unit (CFU) assay, morphological analyses, and qPCR-based gene expression analyses of HBB and HBG2. RESULTS: Both 2D and 3D differentiation protocols led to the induction of CD34+/CD43+ HSPCs. The 3D protocol showed good efficiency (>50%) and high productivity (45-fold) for HSPC induction and increased the frequency of BFU-E, CFU-E, CFU-GM, and CFU-GEMM colonies. We also produced CD71+/CD235a+ cells (>65%) with a 630-fold cell expansion relative to that at the beginning of the 3D protocol. After erythroid maturation, we observed 95% CD235a+/DRAQ5- enucleated cells, orthochromatic erythroblasts, and increased expression of fetal HBG2 compared to adult HBB. CONCLUSION: A robust 3D protocol for erythroid differentiation was identified using SCD-iPSCs and comparative analyses; however, the maturation step remains challenging and requires further development.

Macrophages: key players in erythrocyte turnover

ABSTRACT The development of red blood cells (RBCs), or erythropoiesis, occurs in specialized niches in the bone marrow, called erythroblastic islands, composed of a central macrophage surrounded by erythroblasts at different stages of differentiation. Upon anemia or hypoxemia, erythropoiesis extends to extramedullary sites, mainly spleen and liver, a process known as stress erythropoiesis, leading to the expansion of erythroid progenitors, iron recruitment and increased production of reticulocytes and mature RBCs. Macrophages are key cells in both homeostatic and stress erythropoiesis, providing conditions for erythroid cells to survive, proliferate and differentiate. During RBCs aging and injury, macrophages play a fundamental role again, performing the clearance of these cells and recycling iron for new erythroblasts in development. Thus, macrophages are crucial components of the RBCs turnover and in this review, we aimed to cover the main known mechanisms involved in the process of birth and death of RBCs, highlighting the importance of macrophage functions in the whole RBC lifecycle.

Macrophages: key players in erythrocyte turnover.

The development of red blood cells (RBCs), or erythropoiesis, occurs in specialized niches in the bone marrow, called erythroblastic islands, composed of a central macrophage surrounded by erythroblasts at different stages of differentiation. Upon anemia or hypoxemia, erythropoiesis extends to extramedullary sites, mainly spleen and liver, a process known as stress erythropoiesis, leading to the expansion of erythroid progenitors, iron recruitment and increased production of reticulocytes and mature RBCs. Macrophages are key cells in both homeostatic and stress erythropoiesis, providing conditions for erythroid cells to survive, proliferate and differentiate. During RBCs aging and injury, macrophages play a fundamental role again, performing the clearance of these cells and recycling iron for new erythroblasts in development. Thus, macrophages are crucial components of the RBCs turnover and in this review, we aimed to cover the main known mechanisms involved in the process of birth and death of RBCs, highlighting the importance of macrophage functions in the whole RBC lifecycle.

Hemoglobin Mass, Blood Volume and VO2max of Trained and Untrained Children and Adolescents Living at Different Altitudes.

Introduction: To a considerable extent, the magnitude of blood volume (BV) and hemoglobin mass (Hbmass) contribute to the maximum O2-uptake (VO2max), especially in endurance-trained athletes. However, the development of Hbmass and BV and their relationships with VO2max during childhood are unknown. The aim of the present cross-sectional study was to investigate Hbmass and BV and their relationships with VO2max in children and adolescents. In addition, the possible influence of endurance training and chronic hypoxia was evaluated. Methods: A total of 475 differently trained children and adolescents (girls n = 217, boys n = 258; untrained n = 171, endurance trained n = 304) living at two different altitudes (∼1,000 m, n = 204, ∼2,600 m, n = 271) and 9-18 years old participated in the study. The stage of puberty was determined according to Tanner; Hbmass and BV were determined by CO rebreathing; and VO2max was determined by cycle ergometry and for runners on the treadmill. Results: Before puberty, there was no association between training status and Hbmass or BV. During and after puberty, we found 7-10% higher values in the trained groups. Living at a moderate altitude had a uniformly positive effect of ∼7% on Hbmass in all groups and no effect on BV. The VO2max before, during and after puberty was strongly associated with training (pre/early puberty: boys +27%, girls +26%; mid puberty: +42% and +45%; late puberty: +43% and +47%) but not with altitude. The associated effects of training in the pre/early pubertal groups were independent of Hbmass and BV, while in the mid- and late pubertal groups, 25% of the training effect could be attributed to the elevated Hbmass. Conclusions: The associated effects of training on Hbmass and BV, resulting in increased VO2max, can only be observed after the onset of puberty.

Is there an association between the plasma levels of uremic toxins from gut microbiota and anemia in patients on hemodialysis?

BACKGROUND: Anemia is one of the most frequent complications in patients with chronic kidney disease (CKD). Despite being multifactorial, the relative or absolute deficiency of erythropoietin production is the leading cause. Recent studies have shown that uremic toxins produced by the gut microbiota also may play a role in the genesis of anemia in these patients. OBJECTIVE: To evaluate the possible association between uremic toxins plasma levels and anemia in patients with CKD on hemodialysis (HD). METHODS: This cross-sectional study evaluated one hundred fifty-four patients (53.2% men, 51.2 ± 11.2 years, hemoglobin (Hb) levels of 11.2 ± 1.6 g/dL). Biochemical variables such as urea, creatinine, hemoglobin, hematocrit, were measured according to standard methods and uremic toxins such as indoxyl sulfate (IS), indole-3-acetic acid (IAA), p-cresyl sulfate (p-CS) plasma levels were measured by reverse-phase high-performance liquid chromatography (RP-HPLC). RESULTS: The levels of uremic toxins such as IS, IAA, p-CS were increased in all patients. However, no correlation was found between uremic toxins plasma levels and anemia parameters. Only patients with Hb < 11 g/dL presented a negative correlation between hematocrit and IAA plasma levels. CONCLUSION: There is no strong evidence that uremic toxins produced by the gut microbiota may be associated with anemia in patients with CKD on HD.

Morphological and Transcriptional Changes in Human Bone Marrow During Natural Plasmodium vivax Malaria Infections.

BACKGROUND: The presence of Plasmodium vivax malaria parasites in the human bone marrow (BM) is still controversial. However, recent data from a clinical case and experimental infections in splenectomized nonhuman primates unequivocally demonstrated the presence of parasites in this tissue. METHODS: In the current study, we analyzed BM aspirates of 7 patients during the acute attack and 42 days after drug treatment. RNA extracted from CD71+ cell suspensions was used for sequencing and transcriptomic analysis. RESULTS: We demonstrated the presence of parasites in all patients during acute infections. To provide further insights, we purified CD71+ BM cells and demonstrated dyserythropoiesis and inefficient erythropoiesis in all patients. In addition, RNA sequencing from 3 patients showed that genes related to erythroid maturation were down-regulated during acute infections, whereas immune response genes were up-regulated. CONCLUSIONS: This study thus shows that during P. vivax infections, parasites are always present in the BM and that such infections induced dyserythropoiesis and ineffective erythropoiesis. Moreover, infections induce transcriptional changes associated with such altered erythropoietic response, thus highlighting the importance of this hidden niche during natural infections.

Hemoglobina reticulocitaria y su utilidad clínica en el diagnóstico temprano de eritropoyesis por deficiencia de hierro absoluto en mujeres adolescentes / Reticulocyte hemoglobin and its clinical utility in the early diagnosis of erythropoiesis due to absolute iron deficiency in adolescent women / Hemoglobina de reticulócitos e sua utilidade clínica no diagnóstico precoce da eritropoiese por deficiência absoluta de ferro em mulheres adolescentes

La hemoglobina reticulocitaria es un nuevo parámetro dentro de los autoanalizadores hematológicos de cuarta generación, siendo indispensable en el diagnóstico y manejo de eritropoyesis deficiente en hierro, especialmente la deficiencia funcional de hierro, el secuestro de hierro y la deficiencia absoluta de hierro. Además, este parámetro demuestra ser más preciso que las pruebas bioquímicas como el hierro sérico, la ferritina y la saturación de transferrina, en la detección precoz de eritropoyesis deficiente en hierro. El objetivo de la investigación fue describir la utilidad clínica de la hemoglobina reticulocitaria (CHr) en el diagnóstico temprano de eritropoyesis por deficiencia de hierro absoluto en mujeres adolescentes. El tipo de investigación fue descriptivo, analítico, el diseño de campo transversal. La muestra voluntaria, no aleatoria estuvo constituida por 62 mujeres adolescentes con edades comprendidas entre los 14 y 19 años. Como resultado se encontró que el 97% de la muestra tiene disminución de la CHr, indicando eritropoyesis deficiente en hierro, mientras que un 3% de las adolescentes presentan valores normales para la CHr, se realizó la relación diagnostica entre pruebas de laboratorio tales como CHr y el Hierro sérico. También se reportó que el 93% de la muestra presenta déficit de hierro sin anemia, y un 7% tiene anemia ferropénica, el rango de edad con mayor predominio de anemia ferropénica fue entre los 14 y 16 años. Se concluye que la CHr es de utilidad clínica y una nueva herramienta de diagnóstico temprano de eritropoyesis por deficiencia de hierro.

Reticulocyte hemoglobin is a new parameter within the fourth generation hematological autoanalyzers, being indispensable in the diagnosis and management of iron deficient erythropoiesis, especially functional iron deficiency, iron sequestration and absolute iron deficiency. Moreover, this parameter proves to be more accurate than biochemical tests such as serum iron, ferritin and transferrin saturation in the early detection of iron deficient erythropoiesis. The aim of the research was to describe the clinical utility of reticulocyte hemoglobin (CHr) in the early diagnosis of absolute iron deficiency erythropoiesis in adolescent females. The type of research was descriptive, analytical, cross-sectional field design. The voluntary, non-random sample consisted of 62 adolescent females aged between 14 and 19 years. As a result, it was found that 97% of the sample had decreased CHr, indicating iron deficient erythropoiesis, while 3% of the adolescents had normal values for CHr. The diagnostic relationship between laboratory tests such as CHr and serum iron was performed. It was also reported that 93% of the sample presented iron deficiency without anemia, and 7% had iron deficiency anemia; the age range with the highest prevalence of iron deficiency anemia was between 14 and 16 years of age. It is concluded that HRH is clinically useful and a new tool for early diagnosis of erythropoiesis due to iron deficiency.

A hemoglobina reticulócita é um novo parâmetro dentro da quarta geração de auto-analisadores hematológicos, sendo indispensável no diagnóstico e manejo da eritropoiese com deficiência de ferro, especialmente deficiência funcional de ferro, seqüestro de ferro e deficiência absoluta de ferro. Além disso, este parâmetro prova ser mais preciso do que testes bioquímicos como ferro sérico, ferritina e saturação da transferrina na detecção precoce de eritropoiese com deficiência de ferro. O objetivo da pesquisa foi descrever a utilidade clínica da hemoglobina reticulocitária (RCHr) no diagnóstico precoce da eritropoiese absoluta de deficiência de ferro em mulheres adolescentes. O tipo de pesquisa foi descritivo, analítico, de corte transversal do campo. A amostra voluntária e não aleatória consistiu de 62 fêmeas adolescentes com idades entre 14 e 19 anos. Como resultado, descobriu-se que 97% da amostra tinha uma diminuição na HRH, indicando uma eritropoiese com deficiência de ferro, enquanto 3% das adolescentes tinham valores normais para HRH. Também foi relatado que 93% da amostra tinha deficiência de ferro sem anemia, e 7% tinha anemia por deficiência de ferro; a faixa etária com maior prevalência de anemia por deficiência de ferro era entre 14 e 16 anos. Conclui-se que o RHH é clinicamente útil e uma nova ferramenta para o diagnóstico precoce da eritropoiese devido à deficiência de ferro.

High-volume endurance exercise training stimulates hematopoiesis by increasing ACE NH2-terminal activity.

One of the health benefits of endurance exercise training (ET) is the stimulation of hematopoiesis. However, the mechanisms underlying ET-induced hematopoietic adaptations are understudied. N-Acetyl-Seryl-Aspartyl-Lysyl-Proline (Ac-SDKP) inhibits proliferation of early hematopoietic progenitor cells. The angiotensin I-converting enzyme (ACE) NH2-terminal promotes hematopoiesis by inhibiting the anti-hematopoietic effect of Ac-SDKP. Here we demonstrate for the first time the role of ACE NH2-terminal in ET-induced hematopoietic adaptations. Wistar rats were subjected to 10 weeks of moderate-(T1) and high-(T2) volume swimming-training. Although both protocols induced classical ET-associated adaptations, only T2 increased plasma ACE NH2-domain activity (by 40%, P=0.0003) and reduced Ac-SDKP levels (by 50%, P<0.0001). T2 increased the number of hematopoietic stem cells (HSCs; ∼200%, P=0.0008), early erythroid progenitor colonies (∼300%, P<0.0001) and reticulocytes (∼500%, P=0.0007), and reduced erythrocyte lifespan (∼50%, P=0.022). Following, Wistar rats were subjected to T2 or T2 combined with ACE NH2-terminal inhibition (captopril (Cap) treatment: 10 mg.kg-1.day-1). T2 combined with ACE NH2-terminal inhibition prevented Ac-SDKP decrease and attenuated ET-induced hematopoietic adaptations. Altogether, our findings show that ET-induced hematopoiesis was at least partially associated with increased ACE NH2-terminal activity and reduction in the hematopoietic inhibitor Ac-SDKP.

Do blood parasites increase immature erythrocytes and mitosis in amphibians? / ¿Causan los parásitos sanguíneos un aumento en los eritrocitos inmaduros y la mitosis en los anfibios?

Abstract Introduction: In amphibians, blood may act as a hematopoietic tissue. However, the knowledge concerning hematological features is scarce, there is not much information that allows an analysis about the possible explanations of this physiological feature. Objective: This study aimed to evaluate the relationship between immature red blood cells (RBCs) mitosis and the presence of blood parasites in amphibians. Methods: We sampled 116 amphibians (31 species) in six Colombian localities. Blood was taken by cardiac puncture or maxillary vein puncture. Smears were prepared, fixed, and Giemsa stained for microscopical analysis. The variables analyzed were the percentage of immature RBCs, mitotic cells in peripheral blood, and blood parasite infection. Data were analyzed using Wilcoxon's rank test and exact Fisher statistical tests. Results: Sixty-two individuals showed mitosis in peripheral blood, and these mitotic RBCs shared morphological features with immature RBCs. Overall, parasite prevalence was 30.1 %, distributed as follows: Trypanosoma (24.1 %), Hepatozoon-like (6 %), Dactylosoma (4.3 %), Karyolysus-like (0.9 %), and Filarioidea (2.6 %). A positive association between the percentage of immature RBCs and the presence of mitotic RBCs was found, and also between the blood parasite infection and the percentage of immature RBCs. Conclusions: In this study, we found that the presence of blood parasites, immature RBCs, and RBCs mitosis are frequent events in amphibians' peripheral blood, and our analysis suggests an association between those features. Thus, the release of immature RBCs and the mitosis of those cells in peripheral blood may be a physiological response to blood parasite infection. Further studies characterizing hematology in amphibians and wildlife, in general, are desirable.

Resumen Introducción: En anfibios, la sangre puede actuar como un tejido hematopoyético. Sin embargo, el conocimiento acerca de las características hematológicas es escaso y no hay información que permita un análisis acerca de las posibles explicaciones a este rasgo fisiológico. Objetivo: La intención de este estudio fue evaluar la relación entre la presencia de eritroblastos, mitosis de glóbulos rojos (GRs) y la infección por hemoparásito en sangre periférica de anfibios. Métodos: Se muestrearon 116 anfibios (31 especies) en seis localidades de Colombia. Se tomaron muestras de sangre mediante punción cardiaca o punción a la vena maxilar. Se prepararon extendidos sanguíneos, se fijaron y tiñeron con Giemsa para su posterior análisis por microscopía. Se analizaron variables como porcentaje de GRs inmaduros, células mitóticas en sangre periférica e infección por hemoparásitos. Los datos fueron analizados mediante el test de rango de Willcoxon y el test exacto de Fisher. Resultados: sesenta y dos individuos evidenciaron mitosis en sangre periférica y dichas mitosis compartían características morfológicas con GRs inmaduros. La prevalencia general de parásitos fue del 30.1 %, distribuido de la siguiente forma: Trypanosoma (24.1 %), Hepatozoon-like (6 %), Dactylosoma (4.3 %), Karyolysus-like (0.9 %), y Filarioidea (2. 6 %). Hay una asociación positiva entre el porcentaje de GRs inmaduros y la presencia de células mitóticas, también se encontró una relación entre la infección por hemoparásitos y el porcentaje de GRs inmaduros. Conclusiones: En este estudio encontramos que la presencia de parásitos sanguíneos, GRs inmaduros y mitosis de GRs son eventos frecuentes en sangre periférica de anfibios, y nuestros resultados sugieren una asociación entre dichas características. Por tanto, la liberación de GRs inmaduros y la mitosis de estas células en sangre periférica podría ser una respuesta fisiológica a infecciones parasitarias. Posteriores estudios que caractericen la hematología en anfibios y en vida silvestre en general, son deseables.

SEOM clinical guidelines for anaemia treatment in cancer patients (2020).

Anaemia is defined by the presence of haemoglobin (Hb) levels < 13 g/dL in men and 12 g/dL in women. Up to 39% of cancer patients present it at the time of diagnosis and up to 40% have iron deficiency. Anaemia causes fatigue, functional deterioration and a reduction in the quality of life; it has also been associated with a poorer response to anti-tumour treatment and lower survival. Basic diagnostic tests for anaemia are simple and should be a routine part of clinical practice. These guidelines review the available evidence on the use of different therapies for treating anaemia: erythropoiesis-stimulating agents, iron supplements, and transfusion of blood products.

Variability in Hemoglobin Levels and the Factors Associated with Mortality in Hemodialysis Patients: A 78-Month Follow-Up Study.

Some studies have described that when the hemoglobin levels of chronic kidney disease (CKD) patients change, especially in those taking erythropoiesis-stimulating agents (ESA), they are associated with unfavorable outcomes such as increased morbidity and mortality, mainly due to cardiovascular events. This prospective cohort study included patients with end-stage renal disease currently undergoing hemodialysis. The initial 6-month clinical evaluation provided data of the variability in hemoglobin, associated blood parameters, and the use of erythropoietin. Subsequently, the patients were followed up for 78 months to evaluate mortality-associated factors. In total, 133 patients completed the 6-month follow-up with a mean age of 47.1 (±13.2) years. The majority were women (51.9%). Six-month hemoglobin levels were as follows: always low (18.0%), intermediate/target (1.5%), always high (0.8%), low-amplitude fluctuation/Hb low (n = 37; 27.8%), low-amplitude fluctuation/Hb high (13.53%), and high-amplitude fluctuation (38.6%), among end-stage renal disease patients. At the end of 78 months, 50 (37.6%) patients died; 70% of deaths were attributed to cardiovascular etiologies. A high variability was observed in hemoglobin levels, which was not associated with mortality. Among all the variables evaluated, age, erythropoietin dose, and transferrin saturation were associated with a higher mortality. Thus, this study suggests that greater attention to erythropoietin doses and transferrin saturation levels may improve the survival of dialysis patients.

Novel erythropoietin-based therapeutic candidates with extra N-glycan sites that block hematopoiesis but preserve neuroplasticity.

Neurological disorders affect millions of people causing behavior-cognitive disabilities. Nowadays they have no effective treatment. Human erythropoietin (hEPO) has been clinically used because of its neurotrophic and cytoprotective properties. However, the erythropoietic activity (EA) should be considered as a side effect. Some analogs like non-sialylated EPO, carbamylated EPO, or EPO peptides have been developed showing different weaknesses: erythropoiesis preservation, low stability, potential immunogenicity, or fast clearance. Herein, we used a novel strategy that blocks the EA but preserves hEPO neurobiological actions. N-glycoengineering was accomplished to add a new glycosylation site within the hEPO sequence responsible for its EA. hEPO-derivatives were produced by CHO.K1 cells, affinity-purified and functionally analyzed studying their in vitro and in vivo EA, their in vitro neuronal plasticity in hippocampal neurons and their neuroprotective action by rescuing hippocampal neurons from apoptosis. Muteins Mut 45_47 (K45 > N45 + N47 > T47), Mut 104 (S104 > N104), and Mut 151_153 (G151 > N151 + K153 > T153) lost their EA but preserved their neuroprotection activity and enhanced neuroplasticity more efficiently than hEPO. Interestingly, Mut 45_47 resulted in a promising candidate to explore as neurotherapeutic considering not only its biopotency but also its pharmacokinetic potential due to the hyperglycosylation.

Erythroid Differentiation and Heme Biosynthesis Are Dependent on a Shift in the Balance of Mitochondrial Fusion and Fission Dynamics.

Erythropoiesis is the most robust cellular differentiation and proliferation system, with a production of ∼2 × 1011 cells per day. In this fine-tuned process, the hematopoietic stem cells (HSCs) generate erythroid progenitors, which proliferate and mature into erythrocytes. During erythropoiesis, mitochondria are reprogrammed to drive the differentiation process before finally being eliminated by mitophagy. In erythropoiesis, mitochondrial dynamics (MtDy) are expected to be a key regulatory point that has not been described previously. We described that a specific MtDy pattern occurs in human erythropoiesis from EPO-induced human CD34+ cells, characterized predominantly by mitochondrial fusion at early stages followed by fission at late stages. The fusion protein MFN1 and the fission protein FIS1 are shown to play a key role in the progression of erythropoiesis. Fragmentation of the mitochondrial web by the overexpression of FIS1 (gain of fission) resulted in both the inhibition of hemoglobin biosynthesis and the arrest of erythroid differentiation, keeping cells in immature differentiation stages. These cells showed specific mitochondrial features as compared with control cells, such as an increase in round and large mitochondrial morphology, low mitochondrial membrane potential, a drop in the expression of the respiratory complexes II and IV and increased ROS. Interestingly, treatment with the mitochondrial permeability transition pore (mPTP) inhibitor, cyclosporin A, rescued mitochondrial morphology, hemoglobin biosynthesis and erythropoiesis. Studies presented in this work reveal MtDy as a hot spot in the control of erythroid differentiation, which might signal downstream for metabolic reprogramming through regulation of the mPTP.

Gemfibrozil Induces Anemia, Leukopenia and Reduces Hematopoietic Stem Cells via PPAR-α in Mice.

Hypercholesterolemia, also called high cholesterol, is a form of hyperlipidemia, which may be a consequence of diet, obesity or diabetes. In addition, increased levels of low-density lipoprotein (LDL) and reduced levels of high-density lipoprotein (HDL) cholesterol are associated with a higher risk of atherosclerosis and coronary heart disease. Thus, controlling cholesterol levels is commonly necessary, and fibrates have been used as lipid-lowering drugs. Gemfibrozil is a fibrate that acts via peroxisome proliferator-activated receptor alpha to promote changes in lipid metabolism and decrease serum triglyceride levels. However, anemia and leukopenia are known side effects of gemfibrozil. Considering that gemfibrozil may lead to anemia and that gemfibrozil acts via peroxisome proliferator-activated receptor alpha, we treated wild-type and peroxisome proliferator-activated receptor alpha-knockout mice with gemfibrozil for four consecutive days. Gemfibrozil treatment led to anemia seven days after the first administration of the drug; we found reduced levels of hemoglobin, as well as red blood cells, white blood cells and a reduced percentage of hematocrits. PPAR-alpha-knockout mice were capable of reversing all of those reduced parameters induced by gemfibrozil treatment. Erythropoietin levels were increased in the serum of gemfibrozil-treated animals, and we also observed an increased expression of hypoxia-inducible factor-2 alpha (HIF-2α) and erythropoietin in renal tissue, while PPAR-alpha knockout mice treated with gemfibrozil did not present increased levels of serum erythropoietin or tissue HIF-2α and erythropoietin mRNA levels in the kidneys. We analyzed bone marrow and found that gemfibrozil reduced erythrocytes and hematopoietic stem cells in wild-type mice but not in PPAR-alpha-knockout mice, while increased colony-forming units were observed only in wild-type mice treated with gemfibrozil. Here, we show for the first time that gemfibrozil treatment leads to anemia and leukopenia via peroxisome proliferator-activated receptor alpha in mice.

Acai Extract Transiently Upregulates Erythropoietin by Inducing a Renal Hypoxic Condition in Mice.

Acai (Euterpe oleracea Mart. Palmae, Arecaceae) is a palm plant native to the Brazilian Amazon. It contains many nutrients, such as polyphenols, iron, vitamin E, and unsaturated fatty acids, so in recent years, many of the antioxidant and anti-inflammatory effects of acai have been reported. However, the effects of acai on hematopoiesis have not been investigated yet. In the present study, we administered acai extract to mice and evaluated its hematopoietic effects. Acai treatment significantly increased the erythrocytes, hemoglobin, and hematocrit contents compared to controls for four days. Then, we examined the hematopoietic-related markers following a single injection. Acai administration significantly increased the levels of the hematopoietic-related hormone erythropoietin in blood compared to controls and also transiently upregulated the gene expression of Epo in the kidney. Furthermore, in the mice treated with acai extract, the kidneys were positively stained with the hypoxic probe pimonidazole in comparison to the controls. These results demonstrated that acai increases the erythropoietin expression via hypoxic action in the kidney. Acai can be expected to improve motility through hematopoiesis.