Pathogenesis Of Anemia Research Articles

Gut Microbiota Correlates With Clinical Responsiveness to Erythropoietin in Hemodialysis Patients With Anemia.

The main treatment for renal anemia in end-stage renal disease (ESRD) patients on hemodialysis is erythropoiesis (EPO). EPO hyporesponsiveness (EH) in dialysis patients is a common clinical problem, which is poorly understood. Recent searches reported that gut microbiota was closely related to the occurrence and development of ESRD. This study aims to explore the changes in gut microbiota between ESRD patients with different responsiveness to EPO treatment. We compared the gut microbiota from 44 poor-response (PR) and 48 good-response (GR) hemodialysis patients treated with EPO using 16S rDNA sequencing analysis. The results showed that PR patients displayed a characteristic composition of the gut microbiome that clearly differed from that of GR patients. Nine genera (Neisseria, Streptococcus, Porphyromonas, Fusobacterium, Prevotella_7, Rothia, Leptotrichia, Prevotella, Actinomyces) we identified by Lasso regression and ROC curves could excellently predict EH. In contrast, five genera (Faecalibacterium, Citrobacter, Bifidobacterium, Escherichia–Shigella, Bacteroides) identified by the same means presented a protective effect against EH. Analyzing the correlation between these biomarkers and clinical indicators, we found that gut microbiota may affect response to EPO through nutritional status and parathyroid function. These findings suggest that gut microbiota is altered in hemodialysis patients with EH, giving new clues to the pathogenesis of renal anemia.

Postoperative anaemia and patient-centred outcomes after major abdominal surgery: a retrospective cohort study

BackgroundCompared with anaemia before surgery, the underlying pathogenesis and implications of postoperative anaemia are largely unknown. MethodsThis retrospective cohort study analysed prospective data obtained from 2983 adult patients across 47 centres enrolled in a clinical trial evaluating restrictive and liberal intravenous fluids. The primary endpoint was persistent disability or death up to 90 days after surgery. Secondary endpoints included major septic complications, hospital stay, and patient quality of recovery using a 15-item quality of recovery (QoR-15) score, hospital re-admissions, and disability-free survival up to 12 months after surgery. Anaemia and disability were defined according to the WHO definitions. Multivariable regression was used to adjust for baseline risk and surgery. ResultsA total of 2983 patients met inclusion criteria for this study, of which 78.5% (95% confidence interval [CI], 76.7–80.1%) had postoperative anaemia. Patients with postoperative anaemia had a higher adjusted risk of death or disability up to 90 days after surgery when compared with those without anaemia: 18.2% vs 9.2% (risk ratio [RR]=1.51; 95% CI, 1.10–2.07, P=0.011); lower QoR-15 scores on Day 3 and Day 30, 105 (95% CI, 87–119) vs 114 (95% CI, 99–128; P<0.001), and 130 (95% CI, 112–140) vs 139 (95% CI, 121–144; P<0.011), respectively; higher adjusted risk of a composite of mortality/septic complications, 2.01 (95% CI, 1.55–42.67; P<0.001); unplanned admission to ICU (RR=2.65; 95% CI, 1.65–4.23; P<0.001); and longer median (inter-quartile range [IQR]) hospital stays, 6.6 (4.4–12.4) vs 3.7 (2.5–6.5) days (P<0.001). ConclusionsPostoperative anaemia is common and is independently associated with poor outcomes after surgery. Optimal prevention and treatment strategies need to be investigated. Clinical trial registrationNCT04978285 (ClinicalTrials.gov).

PB2246: FEATURES OF THE SECRETION OF HEPCIDIN, A SOLUBLE TRANSFERRIN RECEPTOR DEPENDING ON THE TYPE OF ANEMIA IN PATIENTS WITH MALIGNANT NEOPLASMS

Background: Anaemia of chronic disease or anaemia of chronic inflammation is the most common cause of anaemia in admitted patients. This anemia can be a consequence of several states such as malignancies, chronic infections and auto-immune diseases, thereby indicating the multiplicity in pathogenetic pathways. Aims: to study the secretion of hepcidin a soluble transferrin receptor (sTfR) in patients with malignant neoplasms with anemia of chronic diseases (ACD), iron deficiency anemia (IDA) and an ACD/IDA combination and to investigate their effect on the development of anemia Methods: 106 patients with stage II-IV of solid malignant neoplasms were examined: 84 with anemia (55 men, 29 women, 67.1±9.9 year olds), 22 without anemia (17 men, 5 women, 60.2±14.9 year olds). According to Van Santen and Worwood criteria, by determining the transferrin saturation index (TSI), ferritin, C-reactive protein (CRP), patients were divided into 4 groups: group 1 - ACD, 31 (20/11 patients (hemoglobin 99.2[IQR,87-118], erythrocytes 3.5[IQR,3.1-3.9], TSI 19.9[IQR,12.6-22], ferritin 443.4[IQR,361.9-574.9], CRP 137.1[IQR,89.7-155.2]), group 2 – ACD/IDA, 28 (18/10) patients (hemoglobin 111[IQR,91-128], erythrocytes 4.02[IQR,3.3-4.5], TSI 12.7[IQR,7.4-20.5], ferritin 220.5[IQR,102.7-370.6], CRP 53.4[IQR,14.5-64.5]), group 3 - IDA, 25(17/8) patients (hemoglobin 107 [IQR,96.5-121.5], erythrocytes 4.1[IQR,3.7-4.5], TSI 7.3[IQR,4.2-12.5], ferritin 19.3[IQR,10-24.1], CRP 14[IQR,6.6-23.9]), group 4(control) - 22 patients without anemia (hemoglobin 135.3[IQR,125-150], erythrocytes 4.4[IQR,3.9-4.9], TSI 16.8[IQR,12.4-21.6], ferritin 111[IQR,25.7-189.2], CRP 11.4[IQR,3.3-16.8]). The significance of differences between several unrelated groups was determined using the Kruskal-Wallis test at a significance level (p) of less than 0.05. To assess the relationship between the variables, the Spearman correlation coefficient (r) was calculated. Results: the ACD group had the highest concentrations of CRP, ferritin in comparison with the other groups (p<0.05). The TSI in the ACD group was higher compared to the IDA and ACD/IDA groups (p<0.05), and did not differ from the control group (p>0.05). The ACD group had the maximum concentration of hepcidin (47.3[IQR,29.7-60.5]) compared with the ACD/IDA group (34.6[IQR, 26.6-50]) (p<0.05), the IDA group (6.16[IQR,1.8-10]) (p<0.05) and the control group (23.5[IQR,4.7-45.4) (p<0.05). The concentration of sTfR in patients with anemia did not differ (p>0.05) and amounted to 26.1[IQR,19.8-28.3] in ACD, 23[IQR,13.3-21.1] in ACD/IDA, 28.4[IQR,16.1-34.4] in IDA, 16.8[IQR,13.7-18.8] in the control group. In all groups with anemia, the concentration of sTfR was higher compared to the control group (p<0.05). A correlation was found between the number of erythrocytes and the concentration of hepcidin (r=-0.57), as well as between the concentration of hemoglobin and sTfR (r=-0.57). Summary/Conclusion: Patients with solid malignancies may have IDA, ACD, or a combination of both. The high concentration of hepcidin in patients with ACD, the presence of a correlation between it and erythrocytes confirms its importance in the development of anemia and the possibility of using it for the diagnosis of ACD. The absence of differences in the concentration of sTfR between patients of the three groups with anemia indicates a low value of this indicator for the differential diagnosis of ACD and IDA. The correlation between sTfR and hemoglobin reflects the importance of sTfR in the pathogenesis of anemia in cancer patients.

A Review: Haemonchus contortus Infection in Pasture-Based Sheep Production Systems, with a Focus on the Pathogenesis of Anaemia and Changes in Haematological Parameters.

Simple SummaryInfection with Haemonchus contortus parasites (haemonchosis) is an important cause of anaemia in sheep. Haemonchosis is a global problem, although sheep that are kept in warm, high rainfall environments are at the greatest risk of infection due to the favourable conditions for H. contortus survival. Following ingestion, the parasites develop in the abomasum of sheep. Various factors such as age, breed, health, nutritional status, and larval challenge influence the severity of clinical disease. Hyperacute, acute, and chronic haemonchosis are reviewed, focusing on the pathophysiology of haemonchosis, associated clinical signs, and haematological and biochemical findings.Haemonchosis is an important cause of anaemia in sheep worldwide, particularly those that are kept in pasture-based systems in warm, high rainfall environments. Potential outcomes vary based on the severity of infection and the sheep’s immune response, however, in some sheep infection can lead to death. The consequences of Haemonchus contortus infection mean that it has been well-studied in a range of different farming systems. However, to our knowledge, there has not been a recent review focused on the pathophysiology of anaemia caused by haemonchosis. Thus, this review provides an in-depth discussion of the literature related to the pathophysiology of haemonchosis and associated clinical signs for hyperacute, acute, and chronic haemonchosis. Additionally, haematological and biochemical findings are presented, and various diagnostic methods are assessed.

Ablation of Tmcc2 Gene Impairs Erythropoiesis in Mice.

(1) Background: Transcriptomic and proteomic studies provide a wealth of new genes potentially involved in red blood cell (RBC) maturation or implicated in the pathogenesis of anemias, necessitating validation of candidate genes in vivo; (2) Methods: We inactivated one such candidate, transmembrane and coiled-coil domain 2 (Tmcc2) in mice, and analyzed the erythropoietic phenotype by light microscopy, transmission electron microscopy (TEM), and flow cytometry of erythrocytes and erythroid precursors; (3) Results: Tmcc2−/− pups presented pallor and reduced body weight due to the profound neonatal macrocytic anemia with numerous nucleated RBCs (nRBCs) and occasional multinucleated RBCs. Tmcc2−/− nRBCs had cytoplasmic intrusions into the nucleus and double membranes. Significantly fewer erythroid cells were enucleated. Adult knockouts were normocytic, mildly polycythemic, with active extramedullary erythropoiesis in the spleen. Altered relative content of different stage CD71+TER119+ erythroid precursors in the bone marrow indicated a severe defect of erythroid maturation at the polychromatic to orthochromatic transition stage; (4) Conclusions: Tmcc2 is required for normal erythropoiesis in mice. While several phenotypic features resemble congenital dyserythropoietic anemias (CDA) types II, III, and IV, the involvement of TMCC2 in the pathogenesis of CDA in humans remains to be determined.

Targeting the NLRP3 inflammasome in Rare hereditary blood disorder Fanconi Anemia

Abstract Fanconi anemia (FA) patients are at higher risk of developing bone marrow failure (BMF) or cancer upon exposure to potential threats like viral infections, bacterial infections, carcinogens, and mutagens. Deleterious mutations in FA genes cause multiple cellular defects which include impaired ability to repair DNA interstrand crosslink lesions in the nucleus and impaired removal of damaged mitochondria via mitophagy in the cytoplasm. Fancc-deficient mice exhibit enhanced inflammatory response and are hypersensitive to lipopolysaccharide-induced septic shock as a result of hematopoietic suppression. Considering the role of inflammation in pathogenesis of Fanconi anemia and bone marrow failure diseases in general, we asked whether inflammasome inhibition could be a promising therapeutic for the treatment of FA. Our studies demonstrate that MCC950, a small molecule inhibitor of the NLRP3 inflammasome, can protect Fancc null mice from LPS-induced hemopoietic suppression and septic shock as evidenced by increased survival rate of Fancc−/− mice. MCC950 partially rescues the thrombocytopenia in peripheral blood and partially restores the loss of megakaryocyte-erythroid progenitor (MEP) and granulocyte-macrophage progenitor (GMP) pools upon LPS challenge. Further, Treatment with MCC950 significantly improved the bone marrow colony-forming capacity of Fancc−/− bone marrow cells in vitro. Our studies demonstrate that MCC950, a small molecule inhibitor of the NLRP3 inflammasome, can protect Fancc null mice from LPS-induced hemopoietic suppression and septic shock and warrants further evaluation as a potential therapeutic strategy in FA.

Pernicious Anemia: The Hematological Presentation of a Multifaceted Disorder Caused by Cobalamin Deficiency.

Pernicious anemia is still a neglected disorder in many medical contexts and is underdiagnosed in many patients. Pernicious anemia is linked to but different from autoimmune gastritis. Pernicious anemia occurs in a later stage of autoimmune atrophic gastritis when gastric intrinsic factor deficiency and consequent vitamin B12 deficiency may occur. The multifaceted nature of pernicious anemia is related to the important role of cobalamin, which, when deficient, may lead to several dysfunctions, and thus, the proteiform clinical presentations of pernicious anemia. Indeed, pernicious anemia may lead to potentially serious long-term complications related to micronutrient deficiencies and their consequences and the development of gastric cancer and type 1 gastric neuroendocrine tumors. When not recognized in a timely manner or when pernicious anemia is diagnosed with delay, these complications may be potentially life-threatening and sometimes irreversible. The current review aimed to focus on epidemiology, pathogenesis, and clinical presentations of pernicious anemia in an attempt to look beyond borders of medical specialties. It aimed to focus on micronutrient deficiencies besides the well-known vitamin B12 deficiency, the diagnostic approach for pernicious anemia, its long-term complications and optimal clinical management, and endoscopic surveillance of patients with pernicious anemia.

Increased suicidal erythrocyte death in patients with hepatitis B-related acute-on-chronic liver failure.

Anemia is a common complication of hepatitis B-related acute-on-chronic liver failure (HB-ACLF). Eryptosis, a suicidal erythrocyte death characterized by phosphatidylserine (PS) externalization and red blood cell-derived microparticle (RMP) generation, decreases erythrocyte lifespan. Herein, we investigated whether enhanced eryptosis is involved in the anemia pathophysiology associated with HB-ACLF. PS exposure, cell volume, cytosolic Ca2+, and reactive oxygen species (ROS) production were determined using flow cytometry. RMPs were extracted using a polyethylene glycol (PEG)-based method. We found that hemoglobin (Hb) and hematocrit (Hct) were significantly lower in patients with HB-ACLF than in healthy controls (HC), patients with chronic hepatitis B (CHB), and patients with cirrhosis. The direct antiglobulin test positive rate was 75.9% in patients with HB-ACLF while its intensity was associated with anemia. The ratio of abnormal erythrocytes was higher in patients with HB-ACLF than in HC, CHB, and cirrhosis. The percentage of PS-exposed erythrocytes was higher in patients with HB-ACLF (2.07 ± 0.11%) compared with HC (0.37 ± 0.05%), CHB (0.38 ± 0.03%), and cirrhosis (0.38 ± 0.04%). The cytosolic Ca2+ and ROS abundance were also higher in patients with HB-ACLF compared with HC, patients with CHB, and patients with cirrhosis, and were inversely correlated with the anemia in patients with HB-ACLF. PS exposure of erythrocytes collected from HC was significantly pronounced following incubation in plasma from patients with HB-ACLF compared with incubation in plasma from HC. The protein concentration and RMPs size significantly increased in patients with HB-ACLF compared with HC. Thus, the anemia in patients with HB-ACLF is associated with increased eryptosis, which is partially triggered by increased cytosolic Ca2+ and oxidative stress.NEW & NOTEWORTHY Acute chronic liver failure (ACLF) is a critical syndrome characterized by multiple organ failures and high short-term mortality. A common complication of HB-ACLF is anemia, however, the mechanism of anemia in HB-ACLF remains to be elucidated. We confirm that the accelerated eryptosis is involved in the pathophysiology of anemia associated with HB-ACLF, which progressively aggravates the clinical outcome. Our study illustrates the mechanism regarding the anemia pathogenesis of HB-ACLF, which may be utilized further toward therapeutic ends.

PECULIARITIES OF OXIDATIVE STRESS IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION WITH IRON DEFICIENCY ANEMIA

The article presents changes in hemogram and oxidative stress in patients with acute myocardial infarction (AMI) on the background of iron deficiency anemia (IDA). Iron deficiency anemia is an additional factor that contributes to the deepening of myocardial ischemia and deepens the processes of peroxidation and damage to cardiomyocytes, which is an important factor in the unfavorable course, both acute period and recovery processes in myocardial necrosis. In order to study the indicators of the general analysis of blood and functional state of the antioxidant system in patients with acute myocardial infarction with IDA, 36 patients with AMI with IDA were examined, including 39% men and 61% women. The first group consisted of 10 patients with AMI without IDA, the second 26 patients with AMI and IDA of varying severity, the control group consisted of 30 healthy individuals. Hemogram parameters, glutathione system function, oxyproline, arginase and magnesium levels in the blood were determined. It has been established that women with mild and moderate anemia predominate among patients with acute myocardial infarction with concomitant iron deficiency anemia. Among men, half of the patients have severe anemia. In addition to a decrease in Hb levels, patients with ACS with IDA have the following laboratory signs of anemia: a tendency to increase the average concentration of hemoglobin in one erythrocyte, low serum iron levels and an increase in serum transferrin levels. In the presence of IDA in patients with ACS there are changes in the antioxidant system. Anemic syndrome in such patients is accompanied by increased concentrations of glutathione transferase and peroxidase, as well as decreased concentrations of oxyproline.&#x0D; Anemia can trigger oxidative stress, and an increase in OS may be associated with changes in cardiac function. Possible cardiovascular effects in patients with comorbid conditions should also be considered.&#x0D; Iron deficiency is the most prevalent micronutrient disorder globally. When severe, iron deficiency leads to anemia, which can be deleterious to cardiac function. Given the central role of iron and oxygen in cardiac biology, multiple pathways are expected to be altered in iron-deficiency anemia, and identifying these requires an unbiased approach.&#x0D; Oxidative stress is an imbalance between free radicals and antioxidant molecules that can play an important role in the pathogenesis of iron-deficiency anemia (IDA).&#x0D; Maintenance of the iron homeostasis is essential for metabolic and physiological processes. Iron plays a critical role in erythropoiesis, is incorporated into erythroblasts and reticulocytes, and has a crucial role in oxygen transport and oxygen storage. Moreover, iron is essential for cardiac and skeletal muscle metabolism, the synthesis and degradation of proteins, lipids, ribonucleic acids, and mitochondrial function.&#x0D; Research has now focused on non-traditional cardiovascular risk factors and the roles of iron and iron deficiency (ID) in patients with cardiovascular disease.&#x0D; The Iron required for immune response, hormonal balance, and plays an important role in regulating oxidative stress and aerobic metabolism. The myocardial tissue has a mainly aerobic cellular metabolism, which depends of mitochondria's Krebs cycle enzymes that need iron as an essential cofactor. In this regard, there is some evidence that myocardial iron deficiency is highly prevalent in HF and may play a role in the progression of the disease.

Prevalence, Pathogenesis and Management of Anemia in Inflammatory Bowel Disease: An IG-IBD Multicenter, Prospective, and Observational Study.

Anemia is a common extraintestinal manifestation of inflammatory bowel disease (IBD), with a 6% to 74% prevalence and a negative impact on patient survival and quality of life, although the prevalence is apparently declining due to improved disease treatment. We aimed to investigate the prevalence, pathogenesis, and clinical correlates of anemia in Italian patients with IBD. A multicenter, prospective, observational study, involving 28 Italian gastroenterology centers, was conducted to investigate the epidemiology and consequences of IBD-associated anemia. Clinical and laboratory data of anemic patients were obtained at study enrolment. Anemia was diagnosed in 737 of 5416 adult IBD outpatients (prevalence 13.6%); females were more commonly affected than males (odds ratio, 1.5; 95% confidence interval [CI], 1.2-1.7) and had more severe anemia. In the majority of cases, anemia was due to iron deficiency (62.5% of cases; 95% CI, 58.3%-66.6%), either isolated or in association with inflammation and/or vitamin deficiencies; anemia of inflammation accounted for only 8.3% of cases. More severe anemia was associated with increasing fatigue and worse quality of life. Only 68.9% of anemic patients with iron deficiency (95% CI, 63.4%-73.8%) and 34.6% of those with vitamin deficiencies (95% CI, 26.2%-44.2%) were properly treated with supplementation therapy. In Italy, the prevalence of IBD-associated anemia is lower than previously reported. Anemia of IBD is most commonly due to iron deficiency and contributes to fatigue and poor quality of life, but remains untreated in a large proportion of patients with iron and/or vitamin deficiencies. This study is registered at clinicaltrials.gov as NCT02872376.

Clinicopathological Parameters and Sialyltransferase Activity in Trypanosoma Congolense-Infected Sheep

Cleavage of erythrocyte surface sialic acid (SA) by the sialidase produced by trypanosomes is implicated in the pathogenesis of anaemia in African animal trypanosomiasis (AAT). Sialyltransferase (ST) mediates the attachment of SA to cell surface glycoproteins and glycolipids of desialylated erythrocytes. ST activities in Trypanosoma congolense-infected sheep and control groups were investigated and variations in their physio-biochemical properties were evaluated. Six (6) apparently healthy Nigerian Yankassa breed of sheep comprising of T. congolense-infected (n=3) and non-infected (n=3) groups were used for the experiment. Parasitaemia and packed cell volume (PCV) were determined daily over a 5-week period. Enzyme kinetics of partially purified ST from the thyroid gland were also evaluated. Anaemia (mean PCV= 18.83±0.71%) was observed in the T. congolense-infected sheep when compared with the non-infected control group (mean PCV 39.75±0.35%) and the observed differences were significant (p &lt; 0.05) after five weeks post infection. Variations were also observed in the physio-biochemical properties (pH, temperature, activation energy) of the ST isolated from the T. congolense-infected and control sheep. This finding is believed to have been an induced response by the host to parasite’s activity and could be exploited further as a possible target in the control of AAT.

POS-267 THE CORRELATION OF HEPCIDIN AND CARDIOVASCULAR DISEASE IN CHILDREN WITH CHRONIC KIDNEY DISEASE

Cardiovascular disease (CVD) is a common complication and an important cause of mortality in children with chronic kidney disease (CKD). Hepcidin is a protein that regulates iron metabolism and has been closely linked with the pathogenesis of anemia in chronic disease. Recent studies have shown a substantial association of hepcidin and CVD in adults with CKD, however this association has not been studied in children. This study aimed to investigate the correlation of hepcidin and CVD in children with chronic kidney disease

In silico study of missense variants of FANCA, FANCC and FANCG genes reveals high risk deleterious alleles predisposing to Fanconi anemia pathogenesis.

Among the 22 Fanconi anemia (FA) reported genes, 90% of mutational spectra were found in three genes, namely FANCA (64%), FANCC (12%) and FANCG (8%). Therefore, this study aimed to identify the high-risk deleterious variants in three selected genes (FANCA, FANCC, and FANCG) through various computational approaches. The missense variant datasets retrieved from the UCSC genome browser were analyzed for their pathogenicity, stability, and phylogenetic conservancy. A total of 23 alterations, of which 16 in FANCA, 6 in FANCC and one variant in FANCG, were found to be highly deleterious. The native and mutant structures were generated, which demonstrated a profound impact on the respective proteins. Besides, their pathway analysis predicted many other pathways in addition to the Fanconi anemia pathway, homologous recombination, and mismatch repair pathways. Hence, this is the first comprehensive study that can be useful for understanding the genetic signatures in the development of FA.

Advances in understanding the pathogenesis and treatment of autoimmune hemolytic anemia

Autoimmune hemolytic anemia (AIHA) is caused by damaged red blood cells due to auto-antibodies targeting its membrane proteins. The heterogeneous group of diseases is divided into two types depending on the thermal amplitude of autoantibodies: warm and cold AIHA. Cold AIHA includes cold agglutin disease and paroxysmal nocturnal hemoglobinuria. AIHA is also divided into primary and secondary AIHA depending on its etiology. Recent advances in understanding the pathogenesis have revealed that AIHA brings not only anemia but also thromboembolic risk or impaired quality of life (QOL). This review describes its pathogenesis, diagnostic approach, and treatment strategies based on the latest information.

РОЛЬ ГИПОКСИЯ-ИНДУЦИБЕЛЬНОГО ФАКТОРА В НОРМЕ И ПРИ ПАТОЛОГИИ

Hypoxia inducible factors (HIFs) are important intracellular regulators of transcription. In normoxia, these proteins undergo posttranslational modifications (hydroxylation) that prevent interaction with coactivators (CBP/p300) and pro- mote HIF degradation. The two main systems that hydroxylate HIF are prolylhydroxylases and factor-inhibiting HIF-1 (Factor-inhibiting HIF-1, FIH-1). Under hypoxia, these inhibitory mechanisms stop working. This leads to dimerization of HIF-1α, HIF-2α, and HIF-3α with constitutively synthesized oxygen-independent HIF-1β. The main vector of HIF operation is adaptation to hypoxia. To perform this task, oxygen capacity of the blood (HIF stimulates the synthesis of erythropoietin and its receptors, iron absorption and transport), angiogenesis, anaerobic ATP production, compensa- tion of intracellular acidosis, etc.). Hyperfunction of HIF underlies carcinogenesis. Tumor cells are characterized by enhanced angiogenesis, proliferation, evasion of apoptosis, immune surveillance, and atypical metabolism (e.g., the Warburg effect). These processes are under the control of HIF. Herminative mutations of HIF genes or other genes involved in the regulation of this transcription factor lead to von Hippel-Lindau disease, congenital erythrocytosis, and other pathologies. Suppression of HIF is being studied as a promising anti-tumor strategy. Hypofunction of HIF contrib- utes to the pathogenesis of anemia in chronic kidney disease and vascular rarity in pathological myocardial hypertro- phy. Stimulation of HIF, by inhibition of prolyl hydroxylases, has been investigated in phase 3 trials and is used to treat anemia in chronic kidney disease. This therapy appears to be comparable in safety profile to the drug erythropoietins. The risk of thrombosis is slightly higher with prolylhydroxylase inhibitors.

Assessment of human parvovirus B19 infection in Egyptian hemodialysis patients.

Parvovirus B19V has been shown to be associated with end-stage renal disease (ESRD) with increased risk of post-infection anemia, especially in hemodialysis (HD) patients. This effect may be due to immunosuppression, insufficient erythropoietin, or short lifespan of red blood cells. Therefore, parvovirus infection should be investigated in this group of patients suffering from anemia or pancytopenia. We assessed the frequency of parvovirus B19 in HD patients attending Suez Canal University Hospital and analyzed the correlation of this infection with hematological parameters in those patients compared with normal individuals. We recruited 80 ESRD patients on hemodialysis and 70 healthy controls. History-taking, full examination, and complete blood count (CBC) were performed for all study subjects. Parvovirus B19 detection was performed through polymerase chain reaction (PCR), which included the QIAamp DNA Mini Kit for extracting DNA, which was amplified using TaqMan Universal Master Mix and detected using TaqMan MGB probes by real-time PCR using Rotor Gene Analyzer (6000). HD patients had a significantly higher frequency of B19V infection than the control group (p= .02). We also found that parvovirus B19-infected HD patients had significantly lower CBC values than uninfected patients. The frequency of parvovirus B19 was significantly higher in HD patients and was associated with lower hematological parameters than in uninfected patients, suggesting a significant role of this virus in the pathogenesis of anemia and/or pancytopenia in ESRD.

The value of erythropoietin in the pathogenesis of anemia of chronic diseases in the rheumatic patients

The features of erythropoietin secretion in patients with a rheumatic pathology and anemia of the chronic diseases in comparison with patients having iron deficiency anemia, as well as the relationship between erythropoietin, hepcidin, proinflammatory, and antiinflammatory cytokines, have been investigated. 126 patients suffering from the rheumatic pathology were examined, including 34 men aged 3655 years and 92 women aged 3860 years. At the same time, 104 (82.5%) patients suffered from anemia, 22 (17.5%) patients did not have it. Patients suffering from anemia, depending on the leading pathogenetic factor, were divided into three groups such as: the 1st group patients suffering from anemia of chronic diseases; 2nd grouppatients suffering from a combination of anemia of chronic diseases and iron deficiency anemia; 3rd grouppatients suffering from iron deficiency anemia. In patients suffering from anemia of chronic diseases, the maximum concentration of interleukin-6, hepcidin, and the minimum concentration of erythropoietin were detected in comparison with the patients suffering from iron deficiency anemia and patients suffering from anemia of chronic diseases, and iron deficiency anemia (p 0.05). The maximum concentration of the erythropoietin has been established in patients suffering from iron deficiency anemia. About the concentrations of interleukin-10 and interleukin-1, tumor necrosis factor-, interferon-, no differences were found in the study groups. A direct correlation was found between the erythropoietin and erythrocytes (r = 0.57), hemoglobin (r = 0.41), hepcidin (r = 0.65). There was a strong negative correlation between the erythropoietin and interleukin-6 (r = 0.75), and a weak relationship with interferon gamma, tumor necrosis factor alpha, interleukin-10, and interleukin-1 (r 0.3). Thus, for patients with a rheumatic profile, a specific molecular profile should be identified, leading to the development of anemia of the chronic diseases, which consists in increased concentrations of hepcidin and interleukin-6 in combination with the insufficient secretion of erythropoietin. The found changes fit into the structure of the previously proposed working version of the classification of anemia of chronic diseases (with a predominant iron deficiency, with disturbances in the regulatory mechanisms of the erythropoiesis, with an insufficient production of erythropoietin). Isolation of the leading factor in the development of anemia of chronic diseases in the future will allow for a more optimal approach to its correction, including with the targeted therapy drugs.

Effects of hypoxia on bone metabolism and anemia in patients with chronic kidney disease.

BACKGROUNDAbnormal bone metabolism and renal anemia seriously affect the prognosis of patients with chronic kidney disease (CKD). Existing studies have mostly addressed the pathogenesis and treatment of bone metabolism abnormality and anemia in patients with CKD, but few have evaluated their mutual connection. Administration of exogenous erythropoietin to CKD patients with anemia used to be the mainstay of therapeutic approaches; however, with the availability of hypoxia-inducible factor (HIF) stabilizers such as roxadustat, more therapeutic choices for renal anemia are expected in the future. However, the effects posed by the hypoxic environment on both CKD complications remain incompletely understood.AIMTo summarize the relationship between renal anemia and abnormal bone metabolism, and to discuss the influence of hypoxia on bone metabolism.METHODSCNKI and PubMed searches were performed using the key words “chronic kidney disease,” “abnormal bone metabolism,” “anemia,” “hypoxia,” and “HIF” to identify relevant articles published in multiple languages and fields. Reference lists from identified articles were reviewed to extract additional pertinent articles. Then we retrieved the and Introduction and searched the results from the literature, classified the extracted information, and summarized important information. Finally, we made our own conclusions.RESULTSThere is a bidirectional relationship between renal anemia and abnormal bone metabolism. Abnormal vitamin D metabolism and hyperparathyroidism can affect bone metabolism, blood cell production, and survival rates through multiple pathways. Anemia will further attenuate the normal bone growth. The hypoxic environment regulates bone morphogenetic protein, vascular endothelial growth factor, and neuropilin-1, and affects osteoblast/osteoclast maturation and differentiation through bone metabolic changes. Hypoxia preconditioning of mesenchymal stem cells (MSCs) can enhance their paracrine effects and promote fracture healing. Concurrently, hypoxia reduces the inhibitory effect on osteocyte differentiation by inhibiting the expression of fibroblast growth factor 23. Hypoxia potentially improves bone metabolism, but it still carries potential risks. The optimal concentration and duration of hypoxia remain unclear. CONCLUSIONThere is a bidirectional relationship between renal anemia and abnormal bone metabolism. Hypoxia may improve bone metabolism but the concentration and duration of hypoxia remain unclear and need further study.

Restoring Dysfunctional Bone Marrow Endothelial Cell Alleviates Aplastic Anemia

BackgroundAplastic anemia (AA) is a life-threatening disease characterized by bone marrow (BM) failure and pancytopenia. Immunosuppressive therapy can rescue most patients with AA. However, the pathogenesis of AA is still not well elucidated and the new strategies need to be developed for AA patients. Increasing evidences suggested the dysfunctional BM microenvironment may be involved in the pathogenesis of AA. As important components of the BM microenvironment, endothelial cells (ECs) play a crucial role in supporting hematopoiesis and regulating immune. However, whether BM ECs are involved in the occurrence of AA and whether repairing BM ECs could improve the hematopoietic and immune status of AA patients remain to be elucidated.AimsTo evaluate the quantity and function of BM ECs from AA patients. Moreover, to determine whether the dysfunctional BM ECs are involved in the occurrence of AA by affecting hematopoiesis and regulating immunity in vitro and in vivo. Finally, to uncover the therapeutic potential of repairing dysfunctional BM ECs to alter the hematopoietic and immunological status in AA patients.MethodsThis study enrolled 30 patients with AA and 30 healthy donors(HD). Flow cytometry and BM in situ immunofluorescence staining were used to analyze the proportion of ECs in BM of the two groups. The level of intracellular reactive oxygen species(ROS) and the proportion of apoptosis were detected by flow cytometry. The functions of BM ECs were evaluated by double-positive staining, migration and tube formation assays. To determine the effect of BM ECs on hematopoiesis and immunity, primary human BM ECs were separately cocultured with CD34 + and CD3 + cells. To further validate the role of BM ECs in the occurrence of AA, a classical AA mice model and VE-cadherin blocking antibody that could antagonize the function of BM ECs were used. Moreover, to explore potential approach of targeting the dysfunctional BM ECs, the exogenous EC infusion or N-acetyl-L-cysteine (NAC, a ROS scavenger) for repairing BM ECs were administrated to the AA mice. To further explore the repairing effect of NAC on BM ECs, the primary BM ECs from AA patients were treated by NAC in vitro and then the functions of BM ECs were evaluated.ResultsCompared with HD, BM ECs in AA patients were decreased and dysfunctional, which characterized by higher levels of ROS and apoptosis, impaired abilities of migration and angiogenesis. Furthermore, dysfunctional BM ECs from AA patients not only impaired their hematopoiesis-supporting ability but also promoted co-cultured T cells to polarize towards pro-inflammatory T cells in vitro, which resulted in an unbalanced T cell subsets. Consistently, AA mice demonstrated decreased BM ECs with increased level of intracellular ROS. Moreover, hematopoietic failure and immune imbalance in AA mice became more severe when the function of BM ECs was antagonized, whereas the administration of NAC or infusion of exogenous EC improved the hematopoietic and immunological status of AA mice via repairing BM ECs in vivo. In addition, we found the NAC treatment also restored the hematopoiesis-supporting ability and immunity-regulating ability of the primary ECs derived from AA patients in vitro.Summary/ConclusionOur study demonstrates for the first time that dysfunctional BM ECs with impaired hematopoiesis-supporting ability and abnormal immunomodulatory ability are involved in the pathogenesis of AA. Although further validation is required, restoring dysfunctional BM ECs via EC infusion or administration of ROS scavenger NAC might be a potential therapeutic approach for AA patients. DisclosuresNo relevant conflicts of interest to declare.

Germline Variants Contribute Significantly to the Pathogenesis of Aplastic Anemia in India

IntroductionAplastic anemia (AA) is characterized by a hypoplastic marrow and bone marrow failure (BMF), leading to peripheral pancytopenia. The treatment for AA currently consists of either hematopoietic stem cell transplant (HSCT) or immunosuppressive therapy (IST) with anti-thymocyte globulin and cyclosporine. We have previously reported poor responses to IST in Indian children with AA while adults (>15 years) show responses of 60%. Therefore, we wanted to study if we could identify constitutional variants in children and young adults with AA.MethodsWe included 102 young patients (≤40 years of age) diagnosed to have AA between year Jan 2006 to April 2021. Genomic DNA was extracted from peripheral blood and relative telomere length (rTL) was measured using quantitative real-time PCR (qPCR). The DNA was used to perform targeted gene capture using a custom capture kit which covered 2196 genes associated with various hematological disorders. Among the 2196 genes, the analysis was restricted to 96 genes associated with AA/IBMFS. Bioinformatics analysis was carried out using Genome Analysis ToolKit (GATK) best practices pipeline. Based on the American College of Medical Genetics and Genomics (ACMG) guidelines, the variants were labelled as pathogenic/likely pathogenic/variant of uncertain significance (VUS)/likely benign/benign. The candidate variants were validated by Sanger sequencing.ResultsThe median age of patients was 9 (0-40) years, including 56 males (55%) and 46 females (45%). There were 15 patients with non-severe AA (NSAA) (15%), 63 with severe AA (SAA) (62%) and 24 with very severe AA (VSAA) (23%). The median relative telomere length of the entire cohort was 0.85 (0.21-3.10). The characteristics of patients age-wise are mentioned in Table 1. Genetic variants were identified in 34 patients (33.3%). This included germline pathological (PAT) genetic variants in 12.7%, variants of limited significance in 9.8% and variants of uncertain significance (VUS) in 10.7% patients. Of the 13 patients who had PAT variants, 6 patients had variants in telomere associated genes. This includes 2 patients with splice site and missense mutation in TINF2 (c.1221+5G>A & R282H); 2 patients with missense mutation in TERT (C828W & S947C); and 2 patients with frameshift and nonsense mutation in RTEL1 (L962S & R1010X). Homozygous MPL mutations [L79Q, R522T & P530L(n=3)] were observed in 5 patients. Two patients had PAT variants in DNAJC21 and NLRP12. Eleven VUS variants were present in the following genes, ATM (n=3), TINF2 (n=1), WRAP53 (n=1), BRCA2 (n=1), AK2 (n=1), FANCA (n=1), FANCN (n=1), ERCC6L2 (n=1) & PRF1 (n=1). The incidence of mutations in the age group ≤5, 6-10, 11-15 and 16-30 years were 51.8%, 25.6%, 27.8% & 33.4% respectively. There was significant difference in median rTL between patients with variants and no variants in the age-group 11-15 years (p=0.043).DiscussionGenetic analyses studies in aplastic anemia patients were confined to single genes or limited gene sets. Keel et al., reported 5.1% of AA patients carried pathogenic variants in inherited BMF/MDS genes. We observed a high frequency of causative genetic variants (37%) in children (<10 years). Our study results highlight the importance of recognizing pathogenic and VUS genetic variants contributing to the pathogenesis of AA in the lower age group. [Display omitted] DisclosuresMathews: Christian Medical College: Patents & Royalties: US 2020/0345770 A1 - Pub.Date Nov.5, 2020; AML: Other: Co-Inventor.