Erythrocyte Life Research Articles

Tambjamines as Fast-Acting Multistage Antimalarials.

Well-tolerated and novel antimalarials that can combat multiple stages of the parasite life cycle are desirable but challenging to discover and develop. Herein, we report results for natural product-inspired novel tambjamine antimalarials. We show that they are potent against liver, asexual erythrocytic, and sexual erythrocytic parasite life cycle stages. Notably, our lead candidate 1 (KAR425) displays excellent oral efficacy with complete clearance of parasites within 72 h of treatment in the humanized Plasmodium falciparum (NOD-scid) mouse model at 50 mg/kg × 4 days. Profiling of compound 1 demonstrated a fast in vitro killing profile. In addition, several other tambjamine analogues cured erythrocytic Plasmodium yoelii infections after oral doses of 30 and 50 mg/kg × 4 days in a murine model while exhibiting good safety and metabolic profiles. This study presents the first account of multiple-stage antiplasmodial activities with rapid killing profile in the tambjamine family.

Reduced Flippase Activity in the Early Life of Mature Erythrocytes Is Associated with Their Shortened Lifespan in Renal Anemia

Reduced Flippase Activity in the Early Life of Mature Erythrocytes Is Associated with Their Shortened Lifespan in Renal Anemia

In vitro investigation of the mechanics of fixed red blood cells based on optical trap micromanipulation and image analysis.

Erythrocyte deformability correlates with various diseases. Single-cell measurements via optical tweezers (OTs) enable quantitative exploration but may encounter inaccuracies due to erythrocyte life cycle mixing. We present a three-step methodology to address these challenges. Firstly, density gradient centrifugation minimizes erythrocyte variations. Secondly, OTs measure membrane shear force across layers. Thirdly, MATLAB analyzes dynamic cell areas. Results combined with membrane shear force data reveal erythrocyte deformational capacity. To further characterize the deformability of diseased erythrocytes, the experiments used glutaraldehyde-fixed erythrocytes to simulate diseased cells. OTs detect increased shear modulus, while image recognition indicates decreased deformation. The integration of OTs and image recognition presents a comprehensive approach to deformation analysis, introducing novel ideas and methodologies for investigating erythrocytic lesions.

Biochemical and biophysical characterization of hemoglobin of erythrocytes from patients suffering from iron deficiency anemia: A pilot study.

Background: Iron deficiency anemia (IDA) is a substantial global health concern, affecting nearly 1 billion individuals worldwide, and women are the more vulnerable due to their various reproductive phases. This study examines physicochemical aspects of erythrocytes in IDA women, especially in reproductive-age women in the North 24 Parganas district of West Bengal. Methods: Fifteen IDA women and eight healthy women aged 25 to 45 years were selected, and only ten volunteers fulfilled the IDA criteria. Observations: Scanning electron microscopic study revealed the formation of echinocytes, indicating asymmetry in the lipid bilayer of the erythrocyte membrane. Although native-PAGE did not show any remarkable change in hemoglobin structure, absorption spectra indicated structural abnormality in the globin chain of hemoglobin. Increased methemoglobin (metHb) formation rate (higher co-oxidation rate) and increased metHb content in the membrane-bound hemoglobin are clear indications of the alteration of physicochemical property of hemoglobin, which may affect erythrocyte life span in IDA. Conclusion: The hemoglobin of IDA individuals is not only quantitatively low, but the quality is also compromised by its structure, and the morphology of erythrocytes is also altered.

Structural and functional features of the erythroid germ in patients with connective tissue dysplasia

Introduction. Connective tissue dysplasia (СTD) is a common condition that affects the function of various components of the body.The aim of the work is to determine the current state of the problem of structural and functional characteristics of erythrocytes in persons with СTD.Materials and methods The authors conducted a search and analysis of works in the scientific electronic library E-library, the Federal Electronic Medical Library of the Ministry of Health of the Russian Federation, the bibliographic database of medical publications Medline using the keywords: erythrocytes, membrane structure, erythrocyte functions, hematopoiesis, erythrocyte life cycle, erythrocyte forms, combined with the terms: connective tissue dysplasia, connective tissue, diagnostic methods, antioxidant protection, lipid peroxidation. Fifty-three sources were selected for the review.Results and Discussion Erythrocytes originate from mesenchymal tissue and have their own structural and functional features in individuals with СTD, namely, a violation of the structure of the submembrane cytoskeleton, a change in the composition and location of phospholipids inside the erythrocyte membrane, leading to a decrease in the plasticity of the blood cell membrane. In addition, the appearance of prehemolytic and degenerative forms of erythrocytes has been detected, which also contributes to a reduction in the life cycle of erythrocytes and a tendency to anemia in people with СTD.Conclusion Individuals with СTD have an increased risk of anemia due to structural and functional features of red blood cells, which may lead to hemolysis, which should be taken into account in the examination and management of patients with СTD.

IN SILICO AND IN VITRO STUDIES OF ACETAZOLAMIDE AS A GAMETOCIDAL AGENT


 
 
 
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 Malaria remains the leading cause of mortality around the world and is the most common disease in Africa and some countries in Asia with the highest number of indigenous cases with Plasmodium falciparum responsible for the majority of the disease burden. Plasmodium has a complex life cycle consisting of multiple stages in two hosts. During the erythrocytic life cycle, it follows one of two developmental fates: terminal sexual differentiation into gametocytes or asexual propagation. Transmission from an infected human host to a susceptible mosquito is done through highly specialized sexual stages gametocytes because they are the only form of malaria parasite that are transmissible to mosquito vector, hence the discovery of new antimalarials with transmission blocking activity remains a key issue in efforts to control malaria and eventually eradicate the disease. In this study the in silico and in vitro gametocidal properties of one of the Sulfonamide drugs Acetazolamide had been checked in order to find new antiplasmodial agent. In vitro cultivation of the RKL-9 (Chloroquine resistant) strain of P. falciparum was continued to develop sexual gametocytic early stages. The drug acetazolamide was screened for gametocidal assay in order to check its transmission blocking activity by targeting early sexual stages of the parasites. Three Plasmodium falciparum proteins Pfg27, Pfs230 and PUF1were selected for molecular docking with the acetazolamide as ligand. HEX 8.0.0 server was used as docking tool and the results obtained were analysed in Discovery studio visualizer. Our findings of in vitro studies revealed that the selected drug acetazolamide possess promising gametocidal activity with IC50 = 4.812µg/ml. Hence the study can be used further for drug formulations as antimalarials targeting Gametocytic stages. Based on the in silico analysis the good binding scores -196.76, -173.87 and -193.29 (Kcal/mol) were obtained for all three selected Plasmodium falciparum proteins Pfg27, Pfs230 and PUF1 with the ligand acetazolamide respectively. Thus the docking energy results of in silico studies also supported our in vitro results that the acetazolamide can be used as an antiplasmodial drug against the gametocytes. Further studies for the mechanism of action of the acetazolamide as a gametocidal agent can be done for preventing the transmission of malaria.

Analysis of MRI-derived spleen iron in the UK Biobank identifies genetic variation linked to iron homeostasis and hemolysis

SummaryThe spleen plays a key role in iron homeostasis. It is the largest filter of the blood and performs iron reuptake from old or damaged erythrocytes. Despite this role, spleen iron concentration has not been measured in a large, population-based cohort. In this study, we quantify spleen iron in 41,764 participants of the UK Biobank by using magnetic resonance imaging and provide a reference range for spleen iron in an unselected population. Through genome-wide association study, we identify associations between spleen iron and regulatory variation at two hereditary spherocytosis genes, ANK1 and SPTA1. Spherocytosis-causing coding mutations in these genes are associated with lower reticulocyte volume and increased reticulocyte percentage, while these common alleles are associated with increased expression of ANK1 and SPTA1 in blood and with larger reticulocyte volume and reduced reticulocyte percentage. As genetic modifiers, these common alleles may explain mild spherocytosis phenotypes that have been observed clinically. Our genetic study also identifies a signal that co-localizes with a splicing quantitative trait locus for MS4A7, and we show this gene is abundantly expressed in the spleen and in macrophages. The combination of deep learning and efficient image processing enables non-invasive measurement of spleen iron and, in turn, characterization of genetic factors related to the lytic phase of the erythrocyte life cycle and iron reuptake in the spleen.

Morphological Types of Anemia Associated with Chronic Renal Diseases

Introduction: Anemia develops early in the course of renal disease and worsens as kidney function declines; a typical consequence of CKD is caused by a disruption in erythropoietin production as well as caused by iron and vitamin shortages, blood loss, shortened erythrocyte life span, chronic inflammation, and the uremic environment. Aim: Our study aimed to identify and classify different types of anemia that complicated patient with chronic kidney disease. Methods: 40 patient were included in this study, 32 males (80%) and 8 females (20%), the age range was 40-70 for male and 48-68 for female .Depending on clinical sign, symptoms and laboratory diagnostic test All those patient are diagnosed previously as a cases of chronic renal failure by clinicians in our city and develop anemia during the course of diseases, so clinicians referred patients to our laboratory to find the cause of anemia. Depending’s on hematological laboratory data, peripheral blood smear examination from these 40 patients, which showed different types of anemia. Results: the most common types of anemia was Normochromic anemia (62.5 %) which develop in 25 patients followed by hypochromic microcytic anemia (8 %) which develop in 8 patients, and followed by macrocytic anemia (12.5 %) which develop in 5 patients and the less common type of anemia was hemolytic anemia (5 %) which was founded in 2 patients.. Conclusion: All types of anaemia can be detected in-patient with different types of renal diseases and it’s important to used different type of laboratory test to diagnosed type of anemia to treat it.

Labile glycated hemoglobin: an underestimated laboratory marker of short term glycemia.

Diabetes mellitus is a major public health problem. Hemoglobin A1c (HbA1c) is a key laboratory parameter in the management of diabetes patients. However, in diabetes monitoring, interpretation of HbA1c results is hampered by the important interindividual variation in red blood cell (RBC) life span. Furthermore, HbA1c only slowly responds to changes in glucose metabolism. Besides HbA1c, there exists a labile HbA1c fraction (l-HbA1c), exhibiting much faster kinetics. As both HbA1c and l-HbA1c are measured by modern standard chromatography, we explored the possibilities of using the l-HbA1c fraction for monitoring glycemia. l-HbA1c and HbA1c fractions were simultaneously assayed on a Tosoh G8 analyzer and expressed as %. l-HbA1c results were compared with serum glucose and HbA1c. Concomitantly, RBC distribution width (RDW) was determined on a Sysmex SN analyzer as a marker for erythrocyte life span. l-HbA1c could be measured with between-run coefficient of variations (CVs) between 2.2 and 2.3%. l-HbA1c correlated with both glycemia (r=0.80) and HbA1c results (r=0.73). In a multiple regression model (r2=0.752), glycemia and HbA1c were the most determining factors. To a lesser extent, RDW correlated with l-HbA1c (r=0.158). Furthermore, the l-HbA1c/HbA1c ratio weakly positively correlated with RDW (r=0.247). L-HBA1c represents an additional marker for monitoring the rapid occurrence of glycemic disorders that escape detection when using only HbA1c and blood glucose. RDW can be used as an indicator of atypical RBCs life span, in which the l-HbA1c fraction may be helpful.

Visible microspectrophotometry coupled with machine learning to discriminate the erythrocytic life cycle stages of P. falciparum malaria parasites in functional single cells.

Malaria was regarded as the most devastating infectious disease of the 21st century until the COVID-19 pandemic. Asexual blood staged parasites (ABS) play a unique role in ensuring the parasite's survival and pathogenesis. Hitherto, there have been no spectroscopic reports discriminating the life cycle stages of the ABS parasite under physiological conditions. The identification and quantification of the stages in the erythrocytic life cycle is important in monitoring the progression and recovery from the disease. In this study, we explored visible microspectrophotometry coupled to machine learning to discriminate functional ABS parasites at the single cell level. Principal Component Analysis (PCA) showed an excellent discrimination between the different stages of the ABS parasites. Support Vector Machine Analysis provided a 100% prediction for both schizonts and trophozoites, while a 92% and 98% accuracy was achieved for predicting control and ring staged infected RBCs, respectively. This work shows proof of principle for discriminating the life cycle stages of parasites in functional erythrocytes using visible microscopy and thus eliminating the drying and fixative steps that are associated with other optical-based spectroscopic techniques.

A better way to detect iron deficiency?

Approximately 10% of US children under 3 years of age will experience some degree of iron deficiency that, even in the absence of overt anemia, has the potential for causing long-term cognitive defects. Clinicians are not only faced with conflicting guidance on screening for iron deficiency but also lack a straightforward method for doing so. About three-quarters of children with iron deficiency will have nominally normal hemoglobin levels and, because of the relatively long life of erythrocytes, changes in the traditional red cell indices associated with iron deficiency anemia are relatively late findings.

Hemoglobin A1c and Fructosamine Evaluated in Patients with Type 2 Diabetes Receiving Peritoneal Dialysis Using Long-Term Continuous Glucose Monitoring

Introduction: Shortened erythrocyte life span and erythropoietin-stimulating agents may affect hemoglobin A_1c (HbA_1c) levels in patients receiving peritoneal dialysis (PD). We compared HbA_1c with interstitial glucose measured by continuous glucose monitoring (CGM) in patients with type 2 diabetes receiving PD. Methods: Fourteen days of CGM (Ipro2, Medtronic) were performed in 23 patients with type 2 diabetes receiving PD and in 23 controls with type 2 diabetes and an estimated glomerular filtration rate over 60 mL/min/1.73 m². Patients were matched on gender and age (±5 years). HbA_1c (mmol/mol), its derived estimate of mean plasma glucose (eMPG_A1c) (mmol/L), and fructosamine (µmol/L) were measured at the end of the CGM period and compared with the mean sensor glucose (mmol/L) from CGM. Results: In the PD group, mean sensor glucose was 0.98 (95% con­fidence interval (CI): 0.43–1.54) mmol/L higher than the eMPG_A1c compared with the control group (p = 0.002) where glucose levels were nearly identical (−0.05 (95% CI: −0.35–0.25) mmol/L). A significant association was found between fructosamine and mean sensor glucose using linear regression with no difference between slopes (p = 0.89) or y-intercepts (p = 0.28). Discussion/Conclusion: HbA_1c underestimates mean plasma glucose levels in patients with type 2 diabetes receiving PD. However, the clinical significance of this finding is undetermined. Fructosamine seems to more accurately reflect glycemic status. CGM or fructosamine could complement HbA_1c to increase the accuracy of glycemic monitoring in the PD population.

Testosterone Therapy in Adult-Onset Testosterone Deficiency: Hematocrit and Hemoglobin Changes

Objective: Hematocrit (HCT)/hemoglobin (Hb) ratio in (%/g/dL) is around 3, with high fidelity between measured and derived Hb (applying the conversion using HCT) in various pathologies. We examined changes in HCT and Hb values and HCT/Hb, compared with baseline, in men with adult-onset testosterone deficiency (TD) given testosterone therapy (TTh). Materials and Methods: Data were analyzed from an observational, prospective registry study at various time points in 353 men with adult-onset TD receiving testosterone undecanoate (median follow-up: 105 months). After establishing baseline HCT/Hb, we compared (cf. baseline) changes in HCT, Hb, and HCT/Hb at 12, 48, 72, and 96 months. Regression analyses determined predictors of HCT and Hb change. Results: TTh was associated with (p < 0.0001) increases in median HCT and Hb; 44% to 49% and 14.5 to 14.9 g/dL at final assessment, respectively. Regression analyses showed that HCT change was associated with baseline HCT and testosterone levels, while Hb change was associated with baseline Hb, HCT, and testosterone levels. In the total cohort and subgroups, HCT/Hb increased significantly at all time points (p < 0.0001, cf. baseline) with over 90% of men demonstrating increases. Linear regression showed that the ratio of HCT change/Hb change (i.e., difference between HCT at the various time points and baseline value/difference between Hb at the various time points and baseline value), following TTh at each time point was higher than the baseline HCT/Hb ratio. Conclusion: HCT increase was greater than we anticipated from the established HCT/Hb of 3. We speculate that increased erythrocyte life span with associated higher Hb loss via vesiculation could account for our observation. This could have a bearing when using HbA1c as an indicator in men with adult-onset TD on TTh.

Hereditary Red Blood Cell Enzymopathies

Red cell metabolic disturbances result in hemolysis, which leads to a significant shortening of the erythrocyte life span. The most common enzyme deficiencies are glucose 6-phosphate dehydrogenase (G6PD) in the antioxidant pathway, pyruvate kinase in the anaerobic glycolysis pathway, and pyrimidine 5’ nucleotidase (P5’N) in the nucleotide metabolism. While the X chromosome inherits G6PD and phosphoglycerate kinase deficiencies, other enzymopathies show autosomal recessive inheritance. Although the causes of hereditary hemolytic disorders are diverse, clinical, laboratory findings and complications overlap. A history of neonatal jaundice requiring phototherapy and exchange transfusion is quite usual. Mild to severe anemia may be accompanied with episodic or constant hemolysis associated with icterus, hyperbilirubinemia, growth retardation, gallstones, splenomegaly, and a variable degree of iron overload. Erythrocyte enzyme disorders should be suspected in patients with severe hemolytic episodes, or chronic hemolysis, after excluding hemoglobinopathies, membranopathies, and immune-mediated hemolysis.

Advances in the creation of animal models of paroxysmal nocturnal hemoglobinuria

ABSTRACT Paroxysmal nocturnal hemoglobinuria (PNH) is a disease caused by a phosphatidylinositol glycan anchor biosynthesis class A (PIG-A) mutation in hematopoietic stem cells. There are three theories about the possible mechanism of the pathogenesis of PNH: immune escape, anti-apoptotic mechanism, and secondary gene mutation. There has been little gain in the knowledge regarding its pathogenesis during the last decade owing to the lack of representative cell lines and animal models. There have been recent reports about the successful creation of PNH mouse and PNH rhesus macaque models. The detection of glycosylphosphatidylinositol-anchor protein (GPI-AP)-deficient cells and/or fluorescently labeled variant of aerolysin (FLAER) test, estimation of erythrocyte life span, and hemolysis-related experiments demonstrated that these animal models of PNH had GPI-AP-deficient blood cells with shortened lifespans and increased sensitivity to complement-activated hemolysis. However, there were no clinical manifestations such as hemolysis and thrombosis in these animal models. This suggested that the PIG-A mutation is one of the several conditions required for PNH, but it alone is not enough to cause PNH.

Congenital Hemolytic Anemias: Is There a Role for the Immune System?

Congenital hemolytic anemias (CHAs) are a heterogeneous group of rare hereditary conditions including defects of erythrocyte membrane proteins, red cell enzymes, and disorders due to defective erythropoiesis. They are characterized by variable degree of anemia, chronic extravascular hemolysis, reduced erythrocyte life span, splenomegaly, jaundice, biliary lithiasis, and iron overload. Although few data are reported on the role of the immune system in CHAs, several immune-mediated mechanisms may be involved in the pathogenesis of these rare diseases. We reported in ~60% of patients with hereditary spherocytosis (HS), the presence of naturally-occurring autoantibodies (NAbs) directed against different membrane proteins (α- and β-spectrin, band 3, and dematin). Positive HS subjects showed a more hemolytic pattern and NAbs were more evident in aged erythrocytes. The latter is in line with the function of NAbs in the opsonization of damaged/senescent erythrocytes and their consequent removal in the spleen. Splenectomy, usually performed to reduce erythrocyte catheresis and improve Hb levels, has different efficacy in various CHAs. Median Hb increase is 3 g/dL in HS, 1.6–1.8 g/dL in pyruvate kinase deficiency (PKD), and 1 g/dL in congenital dyserythropoietic anemias (CDA) type II. Consistently with clinical severity, splenectomy is performed in 20% of HS, 45% of CDAII, and in 60% of PKD patients. Importantly, sepsis and thrombotic events have been registered, particularly in PKD with a frequency of ~7% for both. Furthermore, we analyzed the role of pro-inflammatory cytokines and found that interleukin 10 and interferon γ, and to a lesser extent interleukin 6, were increased in all CHAs compared with controls. Moreover, CDAII and enzymatic defects showed increased tumor necrosis factor-α and reduced interleukin 17. Finally, we reported that iron overload occurred in 31% of patients with membrane defects, in ~60% of CDAII cases, and in up to 82% of PKD patients (defined by MRI liver iron concentration >4 mg Fe/gdw). Hepcidin was slightly increased in CHAs compared with controls and positively correlated with ferritin and with the inflammatory cytokines interleukin 6 and interferon γ. Overall the results suggest the existence of a vicious circle between chronic hemolysis, inflammatory response, bone marrow dyserythropoiesis, and iron overload.

P1004REDUCED ERYTHROCYTE LIFE SPAN IN PATIENTS WITH TYPE 2 DIABETES UNDERGOING LONG-TERM HAEMODIALYSIS

Abstract Background and Aims Anaemia in long-term haemodialysis (HD) is caused by reduced erythropoietin levels but shortened erythrocyte life span is thought to contribute. However, reduced erythrocyte life span has never been documented in patients with type 2 diabetes (T2D) undergoing long-term HD. The aim of the study was to establish if the erythrocyte life span is decreased in in patients with type 2 diabetes (T2D) undergoing long-term HD and to investigate predictors of reduced erythrocyte life span. Method Patients with T2D undergoing long-term HD and patients with T2D without nephropathy (control group) (eGFR above 60ml/min) were included. Erythrocyte life span was measured using Chromium-51 (51Cr) labelled erythrocytes. Blood radiotracer activity was measured 6-8 times over 3-5 weeks to calculate the erythrocyte half-life for each patient. Markers for haemolysis, blood pressure and time spend in dialysis were obtained 5 times over 16 weeks and correlated to the erythrocyte half-life. Results For patients with T2D undergoing HD (n=13), the median half-life was 34.5 days (30.6 - 40.7) compared with 44.6 days (43.5 - 58.0) in the control group (n=10) corresponding to a 23 % difference (p=0.0003). From the half-life, the median erythrocyte life span was estimated to 49.7 days (44.1-58.6) and 64.2 days (62.6-83.5), respectively. For patients with T2D undergoing HD no correlation was found between the erythrocyte half-life and markers of haemolysis, blood pressure or time spend in dialysis. Conclusion The half-life of erythrocytes was reduced by 23 % in patients with T2D undergoing long-term HD compared with a control group. This reflects that erythrocyte life span is reduced in these patients. No specific markers of haemolysis could be correlated to the findings.

Dectection of Erythrocyte Life and Analysis of Its Effect on the Anemia in Patients with Hemophagocytic Syndrome

To detect the erythrocyte life by breath carbon monoxide assay and to analyze the effect of erythrocyte life on the anemia in patients with hemophagocytic syndrome. The breath carbon monoxide test and erythrocyte life assay were performed for 20 cases of hemophagocytic syndrome, at the same time the detection of 20 healthy persons was used as control. The difference of anemia-related indexes was compared between hemophagocytic syndrome patients and healthy persons. The average erythrocyte life of patients with hemophagocytic syndrome was 45.3 days, which was 65% shorter than that of healthy persons. Hemoglobin levels positively correlated with erythrocyte life, while sCD25, breath carbon monoxide concentration and hemophagocytosis negatively correlated with erythrocyte life. Bilirubin level and reticulocyte count showed no correlation with erythrocyte life. Serum level of IL-1β, IL-2, sCD25, IL-6, IL-10, IL-17A, GM-CSF, TNF-α and IFN-γ in patients with newly diagnosed hemophagocytic syndrome were significantly higher than those of healthy persons (P＜0.05). Breath carbon monoxide assay is a rapid and efficient method to assess erythrocyte life. Increased erythrocyte destruction may be an important pathogenic factor for anemia in hemophagocytic syndrome.

Procesiranje i skladištenje krvnih komponenti u uslovima COVID-19 pandemije

The spread of the COVID-19 virus has a strong influence on blood collection, maintaining a stable supply of all blood components and the safety of the transfusion itself. SARS-CoV-2 has a long incubation period (1-14 days, on average 5-6 days, longest reported 24 days) and causes asymptomatic infection in a large number of patients, which is a great challenge in a recruitment of blood donors and achieving a safe transfusion. Precise recommendations and precautions have been adopted regarding the criteria for temporary refusal of blood donors during the COVID-19 pandemic, organization of mobile teams and collection sites, disposal of medical waste, examination of potential donors and mandatory body temperature measurement. Although transmission of COVID-19 via blood and blood components has not been demonstrated, some countries have also introduced mandatory NAT testing for SARS-CoV-2 as a part of blood screening testing. Also, proactive measures have been taken, such as temporary storage of blood in quarantine for 14 days after collection, while special attention is paid to efficient management of blood component stocks and development of a collection plan, in order to avoid shortage of certain blood components or their expiration. The first step in this regard is to revise the measures which have the aim for improving the usability of blood components, ie reducing waste of stocks, which primarily refers to the temporary extension of the shelf life of blood components. Extending the shelf life of erythrocytes (longer than 35 to 49 days, which is defined at the national level) should be considered as early as possible, because once a shortage of erythrocytes occurs, they will be issued long before the expiration date. Previous studies have not shown significant side effects of erythrocyte transfusion with extended shelf life, so it is possible to consider the flexibility of blood processing and erythrocyte storage conditions with mandatory internal process validation and component quality control. The shelf life of platelet concentrate should be extended from 5 days to 7 or even 8 days, with mandatory bacteriological testing or pathogen inactivation. Another option to increase the platelet supply for prophylactic purposes is to reduce the platelet dose by dividing the existing components. Frozen fresh plasma has the longest shelf life (up to 3 years), so maintaining stable reserves is much safer than for cellular components. Liquid plasma (never previously frozen) has a shelf life of 7-40 days, and can be used in conditions of reduced freezer capacity, shortage of staff working on blood processing or for the production of convalescent plasma. Pathogen inactivation of plasma and platelets allows 3-6 log reduction of SARS-CoV-2 and MERS-CoV. The decision to introduce some of the methods of pathogen inactivation should be made taking into account the costs and resources required for implementation. For countries that do not have pathogenic inactivation already in routine practice, its rapid introduction is a big task. For now, the risk of SARS-CoV-2 transmission through the blood appears to be very low, although our understanding of the virus and behavior during a pandemic will improve over time. In this regard, pathogen inactivation of convalescent plasma should also be considered.

Sickle Cell Trait Induces Oxidative Damage on Plasmodium falciparum Proteome at Erythrocyte Stages.

The presence of hemoglobin A-S (HbAS) in erythrocytes has been related to the high production of reactive oxygen species (ROS) and an increased in intracellular oxidative stress that affects the progress of Plasmodium erythrocytic cycle life and attenuates its serious clinical symptoms. Nevertheless, oxidative effects on P. falciparum proteome across the intraerythrocytic cycle in the presence of HbAS traits have not been described yet. Here, an immune dot-blot assay was used to quantify the carbonyl index (C.I) on P. falciparum 3D7 proteome at the different asexual erythrocytic stages. Protein carbonylation on parasites cultivated in erythrocytes from two donors with HbAS increased 5.34 ± 1.42 folds at the ring stage compared to control grown in hemoglobin A-A (HbAA) red blood cells. Whereas at trophozoites and schizonts stages were augmented 2.80 ± 0.52 and 3.05 ± 0.75 folds, respectively. Besides proteins involved in processes of the stress response, recognition and invasion were identified from schizonts carbonylated bands by combining SDS-PAGE with MALDI-TOF-TOF analysis. Our results reinforce the hypothesis that such oxidative modifications do not appear to happen randomly, and the sickle cell trait affects mainly a small fraction of parasite proteins particularly sensitive to ROS.