Search

Abstract: In a phase 1 study (NCT04000165), we established proof of concept for activating pyruvate kinase (PK) in sickle cell disease (SCD) as a viable antisickling therapy. AG-348 (mitapivat), a PK activator, increased adenosine triphosphate (ATP) and decreased 2,3-diphosphoglycerate levels while patients were on treatment, in line with the mechanism of the drug. We noted that the increased hemoglobin (Hb) persisted for 4 weeks after stopping AG-348 until the end of study (EOS). Here, we investigated the pathways modulated by activating PK that may contribute to the improved red blood cell (RBC) survival after AG-348 cessation. We evaluated frozen whole blood samples taken at multiple time points from patients in the phase 1 study, from which RBC ghosts were isolated and analyzed by western blotting for tyrosine phosphorylation of band 3 (Tyr-p-bd3), ankyrin-1, and intact (active) protein tyrosine phosphatase 1B (PTP1B) levels. We observed a significant dose-dependent decrease in mean Tyr-p-bd3 from baseline in the patients, accompanied by an increase in the levels of membrane-associated ankyrin-1 and intact PTP1B, all of which returned to near baseline by EOS. Because PTP1B is cleaved (inactivated) by intracellular Ca2+-dependent calpain, we next measured the effect of AG-348 on ATP production and calpain activity and the plasma membrane Ca2+ ATPase pump-mediated efflux kinetics in HbAA and HbSS erythrocytes. AG-348 treatment increased ATP levels, decreased calpain activity, and increased Ca2+ efflux. Altogether, our data indicate that ATP increase is a key mechanism underlying the increase in hemoglobin levels upon PK activation in SCD. This trial was registered at www.clinicaltrials.gov as #NCT04000165., (Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution.)

Introduction: Thrombospondin-1 (TSP-1) is a key protein product of activated platelets which is significantly increased in sickle cell vaso-occlusive crisis (VOC) and other inflammatory conditions. This study aims to determine TSP-1 levels and their relationship with platelet indices and inflammation., Objective: To evaluate TSP-1 levels in sickle cell anaemia (SCA) patients and assess their relationship with platelet indices and inflammation., Methods: This hospital-based cross-sectional comparative study was conducted in North Western Nigeria from July to December 2022. The study included 120 participants: 80 adults with SCA (40 in VOC) and 40 in steady state (SS)), matched with 40 healthy controls (HbAA). TSP-1 levels were measured using ELISA and haematological parameters were obtained from an automated analyzer. Analysis of variance was used to compare groups and determinants of TSP-1 variability were analyzed using multiple logistic regression. Statistical significance was at p ≤0.05., Results: The mean TSP-1 level was significantly higher in VOC patients (406.0 ± 164.6 ng/mL) compared to SS patients (312.4 ± 145.6 ng/mL) and HbAA controls (192.3 ± 121.2 ng/mL) (p < 0.001). In the SS group, TSP-1 negatively correlated with mean platelet volume (MPV; r = -0.38, p = 0.02) and platelet-large cell ratio (P-LCR; r = -0.36, p = 0.02). White blood cell count (WBC) was the only predictor of TSP-1 variability (β = 10.301, t = 3.843, p < 0.001)., Conclusion: Elevation of TSP-1 during VOC indicates its potential as a biomarker for crisis episodes. In SS patients, TSP-1 is associated with platelet indices, suggesting its role in platelet activation. WBC is a key predictor of TSP-1 variability, emphasizing the influence of inflammation., Competing Interests: The Authors declare that no competing interest exists, (Copyright © 2024 by West African Journal of Medicine.)

Background: Sickle cell disease (SCD) is a prevalent inherited blood disorder. Globally, approximately 515 000 babies are born with SCD annually, with 75% of these births occurring in Africa. Integrating newborn screening (NBS) for SCD into primary healthcare structures, such as immunisation programmes, holds significant promise, with dried blood spots (DBS)-point-of-care technologies (POCT) like HaemoTypeSC offering cost-effective screening solutions. However, scaling up DBS-POCT for NBS of SCD in Africa remains challenging., Objective: This study aims to explore individual, organisational and external factors that may influence the reliability, feasibility, acceptability, adoption and sustainability of using DBS-POCT with HaemoTypeSC for NBS of SCD at primary healthcare centres in African countries., Method: This qualitative study will be conducted in seven African countries that are part of the SickleInAfrica consortium sites. The study design is informed by the Consolidated Framework for Implementation Research (CFIR) and the Implementation Outcome Model. Participants will be mothers whose babies have been diagnosed with SCD, healthcare professionals and policy-makers. In-depth interviews and focus group discussions will be used for data collection. Data analysis will be through thematic analysis., Ethics and Dissemination: Research ethics approvals have been obtained from the seven countries. Written informed consent will be obtained from all participants. The study results will be disseminated in peer-reviewed scientific journals, scientific conferences, reports to national ministries of public health and webinars., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Abstract: Sickle cell disease (SCD) is canonically characterized by reduced red blood cell (RBC) deformability, leading to microvascular obstruction and inflammation. Although the biophysical properties of sickle RBCs are known to influence SCD vasculopathy, the contribution of poor RBC deformability to endothelial dysfunction has yet to be fully explored. Leveraging interrelated in vitro and in silico approaches, we introduce a new paradigm of SCD vasculopathy in which poorly deformable sickle RBCs directly cause endothelial dysfunction via mechanotransduction, during which endothelial cells sense and pathophysiologically respond to aberrant physical forces independently of microvascular obstruction, adhesion, or hemolysis. We demonstrate that perfusion of sickle RBCs or pharmacologically-dehydrated healthy RBCs into small venule-sized "endothelialized" microfluidics leads to pathologic physical interactions with endothelial cells that directly induce inflammatory pathways. Using a combination of computational simulations and large venule-sized endothelialized microfluidics, we observed that perfusion of heterogeneous sickle RBC subpopulations with varying deformability, as well as suspensions of dehydrated normal RBCs admixed with normal RBCs, leads to aberrant margination of the less-deformable RBC subpopulations toward the vessel walls, causing localized, increased shear stress. Increased wall stress is dependent on the degree of subpopulation heterogeneity and oxygen tension and leads to inflammatory endothelial gene expression via mechanotransductive pathways. Our multifaceted approach demonstrates that the presence of sickle RBCs with reduced deformability leads directly to pathological physical (ie, direct collisions and/or compressive forces) and shear-mediated interactions with endothelial cells and induces an inflammatory response, thereby elucidating the ubiquity of vascular dysfunction in SCD., (© 2024 American Society of Hematology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Background: Sickle cell disease (SCD) is a Mendelian disorder characterized by a point mutation in the β-globin gene that leads to sickling of erythrocytes. Several studies have shown that absolute neutrophil count is strongly associated with clinical severity of SCD, suggesting an apparent role of white blood cells (WBC) in SCD pathology. However, the mechanism by which genetic variants lead to WBC count differences in SCD patients remains unclear., Methods: Genome-wide association (GWA) analyses were carried out amongst a cohort of 2409 Brazil SCD participants. Association of WBC count and genetic markers were investigated in homozygous sickle cell anaemia participants and compound heterozygous sickle cell haemoglobin C participants., Results: GWA analysis showed that variants in genes TERT, ACKR1, and FAM3C are associated with WBC count variation. The well-studied association between WBC count and Duffy null phenotype (variant in ACKR1) in healthy populations was replicated, reinforcing the influence of the SNP rs2814778 (T>C) in WBC count., Conclusion: Genetics plays an important role in regulating WBC count in patients with SCD. Our results point to possible mechanisms involved in WBC count variation and as increased WBC count is associated with more severe SCD, these results could suggest potential therapeutic targets for individuals with SCD., (© 2024 British Society for Haematology and John Wiley & Sons Ltd.)

Persistent albuminuria (PA) is common in sickle cell anaemia (SCA). With the association of chronic kidney disease (CKD) with increased mortality, biomarkers that predict its development or progression are needed. We evaluated the association of select biomarkers with PA in adults with SCA using Kruskal-Wallis rank-sum test and logistic regression models, with adjustment for multiple testing. Of 280 subjects, 100 (35.7%) had PA. Median plasma levels of soluble vascular cell adhesion molecule-1 (VCAM-1) (1176.3 vs. 953.4 ng/mL, false discovery rate [FDR] q-value <0.003), thrombin-antithrombin complex (5.5 vs. 4.7 ng/mL, FDR q-value = 0.04), and urinary angiotensinogen (AGT) (12.2 vs. 5.3 ng/mg, FDR q-value <0.003), urinary nephrin (30.6 vs. 27.2 ng/mg, FDR q-value = 0.04), and urinary kidney injury molecule-1 (KIM-1) (0.8 vs. 0.5 ng/mg, FDR q-value <0.003), normalized to urine creatinine, were significantly higher in subjects with PA. In multivariable analysis, only urinary AGT (odds ratio = 1.058, FDR q-value <0.0001) remained a significant predictor of PA. In addition, soluble VCAM-1 (FDR q-value <0.0001), D-dimer (FDR q-value <0.0001), urinary AGT (FDR q-value <0.0001), KIM-1 (FDR q-value <0.0001), and nephrin (FDR q-value <0.0001) were significantly associated with urine albumin-creatinine ratio in multivariable analyses. Longitudinal studies to evaluate the predictive capacity of biomarkers for the development and progression of CKD in SCA are warranted., (© 2024 British Society for Haematology and John Wiley & Sons Ltd.)

Objectives: High rate of alloimmunization in sickle cell disease (SCD) patients poses a significant challenge in finding compatible blood unit. Accurate determination of the blood group genotype of them can help reduce the alloimmunization risk. Tetra ARMS PCR is a novel method that has been utilized recently to investigate SNPs in diseases in a fast and reliable way., Methods: Our study included 104 SCD and sickle thalassemia (Sβ) patients referred to Baghaei-2-Hospital of Ahvaz in 2019 using a nonrandom sampling method. Blood samples were collected for serological and molecular tests. Rh genotyping was performed using Tetra ARMS PCR and compared with the serological results., Results: Based on the Tetra ARMS PCR method, out of 104 patients, 7 (6.7%) were d/d, 40 (38.5%) were D/d, 57 (54.8%) were D/D, 25 (24%) were C/C, 59 (56.7%) were C/c, 20 (19.3%) were c/c, 4 (3.8%) were E/E, 25 (24%) were E/e, and patients 75 (72.2%) were e/e. There were discrepancies in the serological and molecular results for 11 patients., Conclusion: Use of Tetra ARMS PCR in combination with serological methods for determining the Rh blood group system in donors and transfusion-dependent patients represents a remarkable transformation in the field of immunohematology.

Congenital anemias include a broad range of disorders marked by inherent abnormalities in red blood cells. These abnormalities include enzymatic, membrane, and congenital defects in erythropoiesis, as well as hemoglobinopathies such as sickle cell disease and thalassemia. These conditions range in presentation from asymptomatic cases to those requiring frequent blood transfusions, exhibiting phenotypic heterogeneity and different degrees of severity. Despite understanding their different etiologies, all of them have a common pathophysiological origin with congenital defects of erythropoiesis. We can find different types, from congenital sideroblastic anemia (CSA), which is a bone marrow failure anemia, to hemoglobinopathies as sickle cell disease and thalassemia, with a higher prevalence and clinical impact. Recent efforts have focused on understanding erythropoiesis dysfunction in these anemias but, so far, deep gene sequencing analysis comparing all of them has not been performed. Our study used Quant 3' mRNA-Sequencing to compare transcriptomic profiles of four sickle cell disease patients, ten thalassemia patients, and one rare case of SLC25A38 CSA. Our results showed clear differentiated gene map expressions in all of them with respect to healthy controls. Our study reveals that genes related to metabolic processes, membrane genes, and erythropoiesis are upregulated with respect to healthy controls in all pathologies studied except in the SLC25A38 CSA patient, who shows a unique gene expression pattern compared to the rest of the congenital anemias studied. Our analysis is the first that compares gene expression patterns across different congenital anemias to provide a broad spectrum of genes that could have clinical relevance in these pathologies.

Background: Sickle cell disease (SCD) is a genetic blood disorder characterized by a painful vaso-occlusive crisis due to the sickling of red blood cells in capillaries. Complications often lead to liver and renal dysfunctions, contributing to morbidity and mortality, particularly for children under 5. This systematic review and meta-analysis aimed to evaluate the liver and renal functions of people with SCD (HbSS) compared to those without it (HbAA) in Africa., Methods: The protocol was registered with PROSPERO (CRD42022346771). We searched PubMed, Embase, Web of Science, and Google Scholar using the keywords "liver function", "renal function", "sickle cell disease", and "Africa" on 6th May 2023 for peer-reviewed articles with abstracts in English. We included case-control studies comparing SCD (HbSS) with controls without hemoglobinopathies (HbAA). We used the random-effect model to calculate the pooled average values for the blood tests of people with SCD in RStudio version 4.2.2., Results: Overall, 17 articles were analyzed from five African countries involving 1312 people with SCD and 1558 controls. The pooled mean difference of liver enzymes aspartate transaminase (AST) was 8.62 (95% CI - 2.99-20.23, I 2  = 97.0%, p < 0.01), alanine transaminase (ALT) 7.82 (95% CI - 0.16-15.80, I 2  = 99%, p < 0.01) and alkaline phosphatase (ALP) - 2.54 (95% CI - 64.72 - 59.64, I 2  = 99%, p < 0.01) compared to controls. The pooled mean difference for the renal biochemical profiles creatinine - 3.15 (95% CI - 15.02; 8.72, I 2 =99%, p < 0.01) with a funnel plot asymmetry of t = 1.09, df = 9, p = 0.3048 and sample estimates bias of 6.0409. The pooled mean difference for serum urea was - 0.57 (95% CI - 3.49; 2.36, I 2  = 99%, p < 0.01), and the estimated glomerular filtration (eGFR) rate was 19.79 (95% CI 10.89-28.68 mL/min/1.73 m 2 , I 2  = 87%, p < 0.01) compared to controls., Conclusion: People with SCD have slightly elevated liver enzymes and estimated glomerular filtration rates compared to controls in Africa. With all the heterogeneity (I 2 ) > 50%, there was substantial variation in the reported articles' results., Systematic Review Registration: PROSPERO CRD42022346771., (© 2024. The Author(s).)

Rare donor programs are critically important for those patients with rare phenotypes who have produced the associated alloantibodies that necessitate the provision of rare blood components. We describe the American Rare Donor Program (ARDP) and its establishment, members, and policies. The specific phenotypes meeting the ARDP criteria for inclusion are described. Data on the number of rare donors registered by year, and the number of requests for rare blood components received and fulfilled over the 25 years of the program (1998-2023) are provided, along with a description of some notable cases and discussion of how the program supports patients with sickle cell disease., (© 2024 Margaret A. Keller et al., published by Sciendo.)

Many Omani patients with sickle cell disease (SCD) undergo red blood cell (RBC) transfusions that are only matched for ABO and D, making RBC alloimmunization a significant concern in this population. Currently, the integration of molecular assays and hemagglutination testing helps to determine RBC phenotypes and genotypes, facilitating the provision of compatible blood and minimizing additional alloimmunization risks in patients with SCD. Based on this finding, our objective was to use molecular methods to predict the extended antigen profile of Omani patients with SCD across various blood group systems including Rh, Kell, Duffy, Kidd, Colton, Lutheran, Dombrock, Diego, Cartwright, and Scianna. This approach aims to implement RBC matching strategies and enhance daily transfusion practices for these patients. Molecular methods encompassed multiplex polymerase chain reaction for RHD, BeadChip arrays for variants of RHD and RHCE, and ID CORE XT for the primary allelic variants of RBCs. This study enrolled 38 patients with SCD, comprising 34 patients with homozygous HbSS, 1 patient with HbSC, and 3 patients with HbS Oman. The predominant ABO blood group was group O, observed in 44.7 percent of patients, followed by group A in 21.1 percent and group B in 13.2 percent. The most prevalent Rh phenotype predicted from the genotype was D+C+E-c+e+, identified in 34.2 percent of patients. All patient samples were K-, exhibiting the k+ Kp(b+) Js(b+) phenotype, with 81.6 percent demonstrating Fy(a-b-) due to the homozygous FY*02N.01 genotype and 28.9 percent displaying Jk(a+b-). RH variant alleles were detected in five patients (13.2 %), with only one type of RHD variant ( RHD*DIIIa ) and one type of RHCE variant ( RHCE*ceVS.02.01 ) identified. Alloantibodies were present in 26 patients (68.4%). This study presents the initial comprehensive report of extended RBC antigen profiling in Omani patients with SCD, revealing disparities in the prevalence of RBC phenotypes compared with SCD patients from other regions and countries. Furthermore, our findings underscore a high rate of alloimmunization in these patients, emphasizing the need to implement antigen-matching programs to improve daily transfusion practices., (© 2024 Amal Salim Al Breiki et al., published by Sciendo.)

Sickle cell disease (SCD) is an inherited haemoglobinopathy associated with significant morbidity and mortality. Automated red blood cell exchange (aRCE) plays a key role in managing SCD, eliciting both therapeutic and prophylactic effects. The ideal post-apheresis Ht target for chronic aRCE treatment is not yet unanimously recognized, as well as iron homeostasis can be different among patients. Ross et al. reported their experience on the chronic management of SCD patients undergoing aRCE with a final post-exchange Ht higher than the value commonly adopted, analysing red blood cell transfusion requirements and iron-related outcomes in the study population. Commentary on: Ross et al. Automated red blood cell exchange with a post-procedure haematocrit targeted at 34% in the chronic management of sickle cell disease. Br J Haematol 2024; 205:1556-1564., (© 2024 The Author(s). British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Optimal targets for red blood cell exchange (RCE) are not well defined in the chronic management of sickle cell disease. We analysed transfusion requirements and iron-related outcomes in 101 patients on chronic RCE with a post-procedure haematocrit (Ht) targeted at 34%, which is higher than typically used. A majority were of HbSS/HbSβ0 genotype (n = 72) and enrolled for neurological complications (n = 53). Fifty patients had a positive Ht balance with RCE (>2% mean increase from pre-procedure level), while 43 patients maintained a neutral balance. The first group required fewer red blood cell units/year (65 vs. 80, p < 0.001), but a significant proportion were iron overloaded based on R2* with liver MRI (32% vs. none performed) and prescription of iron chelation (52% vs. 0%, p < 0.001, after a median of 19 months). The second group was more likely to receive iron supplementation (6% vs. 56%, p < 0.001). Chronic automated RCE with a post-procedure Ht targeted at 34% is not iron-neutral, and personalized Ht goals may be more appropriate in certain settings. This higher target should be compared with a lower Ht strategy in individuals with similar baseline red cell volumes to assess iron homeostasis and blood product requirements., (© 2024 The Author(s). British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Background and Objectives: Pregnancy in women with sickle cell disease (SCD) is associated with severe complications. Red blood cell (RBC) alloimmunisation is a worrying situation in pregnant women with SCD. This could increase the difficulty in finding a pheno-compatible red blood product. Our study aimed to determine the prevalence of RBC alloantibodies in pregnant women with SCD and to determine the risk factors for alloantibodies formation., Methods/materials: We conducted a prospective study at the "Centre National de Transfusion Sanguine de Bamako" from August 2022 to January 2023. For each participant, we collected important information, including obstetrical and transfusion histories. We performed ABO group, Rh and Kell phenotyping, and antibody screening in all study participants. We performed statistical analysis., Results: We recruited 95 pregnant women with SCD. In our study, 62% of our participant had a history of blood transfusion. Only 23% of our pregnant women with SCD had a history of miscarriage. The prevalence of RBC alloantibodies was 14%. The main antibodies detected were anti-E (38%) and pan-agglutinins (23%). Miscarriage history, blood transfusion history, and pregnancy number were the main risk factors for RBC alloimmunisation., Conclusion: The care of pregnant women with SCD is complex and requires collaboration between haematologists, clinicians and gynaecologists. National guidelines should be implemented to make ABO and D typing, Rh and Kell phenotyping and antibody screening routine for all pregnant women. This would facilitate early detection of high-risk situations. Particular attention should be paid to SCD pregnant women with miscarriage and blood transfusion histories., (© 2024 British Blood Transfusion Society.)

Background: The COVID-19 pandemic disproportionately affected persons with underlying medical conditions. SARS-CoV-2 infection susceptibility and vaccine effectiveness in pediatric hematology-oncology patients were unknown., Methods: From February to July 2022, anti-spike and anti-nucleocapsid Ig were assayed in 354 pediatric hematology-oncology subjects, including 53 oncology patients receiving chemotherapy (cancer), 150 patients with sickle cell disease (SCD), and 151 benign consult and long-term follow-up patients (controls). Participants completed a questionnaire., Results: Frequencies of COVID-19 infection, defined by positive PCR/antigen test or anti-nucleocapsid Ig, were 62% in cancer, 71% in SCD, 52% in controls, with SCD statistically different than controls (p = .001). Infection was associated with COVID-19 exposure, Hispanic/Latino or Black/African American ethnicity, multi-family dwelling, sports participation; COVID-19 booster decreased association with infection. In COVID-19-positive cancer patients, 58% had positive anti-nucleocapsid and 76% had positive anti-spike (≥10 U/mL), compared to essentially 100% seroconversion in SCD and controls (p < .0001, p = .01, respectively). Infection led to high anti-spike (≥2500 U/mL) in 12% cancer, 14% SCD, and 15% controls (p = .93). Vaccination resulted in anti-spike positivity in 90% cancer, 100% SCD, and 100% controls (p = .06), and in high anti-spike in 20% cancer, 47% SCD, and 41% controls (p = .36). Of boosted subjects, one of two cancer, 6/6 SCD, and 19/19 controls exhibited high anti-spike., Conclusions: Cancer patients demonstrated similar SARS-CoV-2 infection frequency as controls, but diminished antibody response to infection and vaccination. SCD patients exhibited seroconversion indistinguishable from controls. Vaccination was associated with higher frequency of high anti-spike than infection; vaccination plus booster was most effective in eliciting high anti-spike antibody detectable beyond 90 days., (© 2024 The Author(s). Pediatric Blood & Cancer published by Wiley Periodicals LLC.)

Abstract: Children and adults with sickle cell disease (SCD) have increases in morbidity and mortality with COVID-19 infections. The American Society of Hematology Research Collaborative Sickle Cell Disease Research Network performed a prospective COVID-19 vaccine study to assess antibody responses and analyze whether messenger RNA (mRNA) vaccination precipitated any adverse effects unique to individuals with SCD. Forty-one participants received 2 doses of the Pfizer-BioNTech vaccine and provided baseline blood samples before vaccination and 2 months after the initial vaccination for analysis of immunoglobulin G (IgG) reactivity against the receptor binding domain (RBD) of the severe acute respiratory syndrome coronavirus 2 spike protein. Six-month IgG reactivity against the viral RBD was also available in 37 patients. Postvaccination reactogenicity was common and similar to the general population. There were no fevers that required inpatient admission. Vaso-occlusive pain within 2 to 3 days of first or second vaccination was reported by 5 participants (12%) including 4 (10%) who sought medical care. Twenty-seven participants (66%) were seropositive at baseline, and all 14 initially seronegative participants (34%) converted to seropositive after vaccination. Overall, mRNA vaccination had a good risk-benefit profile in individuals with SCD. This mRNA vaccine study also marks the first evaluation of vaccine safety and antibody response in very young children with SCD. This trial was registered at www.ClinicalTrials.gov as #NCT05139992., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Objectives: Voxelotor can increase hemoglobin levels in patients living with sickle cell disease (SCD). A clinician who is monitoring voxelotor response may want to know whole-blood voxelotor concentration, but this cannot be measured in most clinical settings. However, voxelotor has been demonstrated to cause "peak splitting" in common methods of hemoglobin measurement such as capillary zone electrophoresis (CZE) and high-performance liquid chromatography (HPLC). We hypothesized that we could use the size of the peak split to estimate the whole-blood concentration., Methods: Blood from people with SCD was dosed with known concentrations of voxelotor, and multiparameter regression was used to derive the relationship of voxelotor concentration to the degree of peak splitting observed. To validate these equations, 21 patients started on voxelotor at 1500 mg/d had blood samples drawn at days 0, 14, 30, and 60. Samples were sent out for gold standard voxelotor concentration testing. The derived equations were then used to calculate voxelotor concentration., Results: Calculated concentrations correlated strongly with measured concentrations for both CZE (R2 = 0.83, P < .001) and HPLC (R2 = 0.76, P < .001). Voxelotor concentration also had a significant effect on increases in hemoglobin (R2 = 0.40, P < .001)., Conclusions: Thus, peak splitting CZE and HPLC can be used to estimate voxelotor concentration., (© The Author(s) 2024. Published by Oxford University Press on behalf of American Society for Clinical Pathology. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Sodium-glucose cotransporter-2 (SGLT-2) is expressed in the kidney and may contribute to anaemia and cardiovascular diseases. The effect of SGLT-2 inhibition on anaemia and vascular endpoints in sickle cell disease (SCD) is unknown. A murine model of SCD was studied to determine the effects of the SGLT-2 inhibitor, empagliflozin, on anaemia and stroke size. The University of Michigan's Precision Health Database was used to evaluate the effect of SGLT-2 inhibitors on anaemia in humans with SCD. SCD mice treated with daily empagliflozin for 8 weeks demonstrated increases in haemoglobin, haematocrit, erythrocyte counts, reticulocyte percentage and erythropoietin compared to vehicle-treated mice. Following photochemical-induced thrombosis of the middle cerebral artery, mice treated with empagliflozin demonstrated reduced stroke size compared to vehicle treated mice. In the electronic health records analysis, haemoglobin, haematocrit and erythrocyte counts increased in human SCD subjects treated with an SGLT-2 inhibitor. SGLT-2 inhibitor treatment of humans and mice with SCD is associated with improvement in anaemic parameters. Empagliflozin treatment is also associated with reduced stroke size in SCD mice suggesting SGLT-2 inhibitor treatment may be beneficial with regard to both anaemia and vascular complications in SCD patients., (© 2024 The Author(s). Journal of Cellular and Molecular Medicine published by Foundation for Cellular and Molecular Medicine and John Wiley & Sons Ltd.)

Purpose: Iron absorption in sickle cell anemia (SCA) remains unclear and studies in adults with SCA are scarce. The aim of this study was to evaluate the iron absorption SCA adults and its association with iron status and hepcidin concentration., Methods: SCA patients (n = 13; SCA total ) and control participants (n = 10) ingested an oral stable iron isotope ( 57 Fe). Iron absorption was measured by inductively coupled plasma mass spectrometry (ICP-MS) 14 days after isotope administration. Patients with ≥ 1000 ng/mL serum ferritin were considered to present iron overload (IO) (SCAio+; n = 3) and others classified without IO (SCAio-; n = 10)., Results: Iron absorption in the control group ranged from 0.3 to 26.5% (median = 0.9%), while it varied from 0.3 to 5.4% in SCAio+ (median = 0.5%) and from 0.3 to 64.2% in the SCAio- (median = 6.9%). Hepcidin median values were 14.1 ng/mL (3.0-31.9 ng/mL) in SCAio-, 6.2 ng/mL (3.3-7.8 ng/mL) in SCAio + and 6.2 ng/mL (0.6-9.3 ng/mL) in control. Iron absorption was associated with ferritin level (r = - 0.641; p = 0.018) and liver iron concentration (LIC; r = - 0.786; p = 0.036) in the SCA total group., Conclusion: Our data suggest that SCAio- individuals may be at risk of developing primary IO. Simultaneously, secondary IO may induce physiological adaptation, resulting in reduced iron absorption. Further studies evaluating intestinal iron absorption using larger sample sizes should be conducted to help establish a safe nutrition approach to be adopted and to ensure the security of food-fortifying public policies for these patients., Trial Registration: This trial was registered at www.ensaiosclinicos.gov.br (Identifier RBR-4b7v8pt)., (© 2024. Springer-Verlag GmbH Germany, part of Springer Nature.)

While sickle cell anemia (SCA) and hereditary spherocytosis (HS) share common features of increased spleen erythrophagocytosis due to increased red blood cell (RBC) turnover, SCA is specifically characterized by susceptibility to infections. In this study, histological lesions in the spleens of pediatric patients with SCA were analyzed, in close correlation with past clinical history and comparatively to HS, healthy and transfused β-thalassemia patients (TDT). An evaluation of red pulp elementary lesions (red pulp fibrosis, iron deposition, number of Gandy-Gamna, and RBC trapping) combined into a severity score was established, as well as B-cell follicles analysis. Quantification on digitalized slides of iron deposition, RBC trapping, and red pulp fibrosis was additionally performed. Spleens from 22 children with SCA, eight with HS, eight with TDT, and three healthy controls (HC) were analyzed. Median age at splenectomy was not different between SCA and HS patients, 6.05 years (range: 4.5-16.0) versus 4.75 (range: 2.2-9.5). Marked heterogeneity was found in SCA spleens in contrast to other conditions. Contrary to previous reports, B-cell follicles were generally preserved in SCA. While RBC trapping was significantly increased in both SCA and HS (compared to TDT and HC), quantitative fibrosis and overall red pulp severity score were significantly increased in SCA spleens compared to other conditions. Moreover, there was an inverse correlation between quantitative fibrosis and number of B-cell follicles, linking these two compartments as well as spleen fibrosis to infectious susceptibility in SCA, potentially through impaired red pulp macrophage scavenging and B-cell subpopulations defects., (© 2024 The Author(s). American Journal of Hematology published by Wiley Periodicals LLC.)

Background: Although genetic polymorphism of the RH blood group system is well known in sub-Saharan Africa, national/regional specificities still remain to be described precisely. For the first time in Cameroon, Central Africa, and in order to better characterize the molecular basis driving RH phenotype variability, as well as to identify the main antigens that may be potentially responsible for alloimmunization, we sought 1) to study the RH genes in a cohort of 109 patients with sickle cell disease; 2) to study the same genes in the corresponding donors whose red blood cells (RBCs) were transfused to the patients (108 donors in 98 patients); 3) to predict RH phenotype on the basis of the molecular data and compare the results with serologic testing; and 4) to identify retrospectively patients at risk for alloimmunization., Materials and Methods: In order to generate an exhaustive dataset, the RH genes of all patient and donor samples were systematically investigated 1) by quantitative multiplex PCR of short fluorescent fragments (QMPSF) for characterization of RHD gene zygosity and potential structural variants (SVs), and 2) by Sanger sequencing for identification of single nucleotide variants (SNVs). Subsequent to molecular analysis, the genotypes and RH phenotype were deduced and predicted, respectively, from reference databases., Results: In a total of 217 Cameroonian individuals, as many as 24 and up to 22 variant alleles were identified in the RHD and RHCE genes, respectively, in addition to the reference alleles. Interestingly, 65 patients with SCD (66.3%) were assumed to be exposed to one or more undesirable RH antigen(s) with varying degrees of clinical relevance., Discussion: Beyond the comprehensive report of the nature and distribution of RH variant alleles in a subset of Cameroonian patients treated by transfusion therapy, this work highlights the need for an extensive review of current practice, including routine serologic typing procedures, preferably in the near future.

Background: Neutrophils in sickle cell disease (SCD) are activated, contributing to disease. Red cell exchange (RCE), with the goal of lowering hemoglobin S (HbS), is an important part of therapy for many SCD patients. Whether RCE impacts neutrophil reactivity is unknown., Study Design and Methods: To determine the effect of RCE on neutrophil activation, SCD patients undergoing RCE in steady-state were enrolled. Neutrophil degranulation responses were examined before/after RCE. Kinetic studies were completed to determine the duration of the effect of RCE on neutrophil function. Degranulation results were examined in relation to white blood cell count, neutrophil count, and HbS levels. The effect of RCE on RBC phosphatidylserine (PS) exposure was examined as a possible contributor to modulation of neutrophil function by RCE., Results: Twenty-two patients with SCD, genotype SS, who underwent RCE (average pre-RCE HbS 33 ± 14%) were included for the study. RCE significantly decreased neutrophil degranulation responses. The effect of RCE on neutrophil activation was unrelated to cell count and instead directly correlated with HbS. The effect of RCE on neutrophil activation was sustained over several days post-apheresis. Furthermore, while increased RBC PS exposure results in increased neutrophil degranulation, RCE decreases RBC PS exposure., Discussion: To our knowledge, this is the first study demonstrating that RCE significantly decreases neutrophil activation in a sustained HbS-dependent manner. Modulation of PS exposure by RCE may be a contributing mechanism by which RCE modulates neutrophil activation. These studies raise the possibility that modulation of neutrophil activation contributes significantly to the therapeutic effect of RCE., (© 2024 AABB.)

Sickle cell anemia (SCA) is characterized by immune system activation and heightened susceptibility to infections. We hypothesized that SCA patients exhibit transcriptional alterations in B-cell-related genes, impacting their peripheral B-cell compartment and leading to dysregulated humoral immunity and increased infection susceptibility. Our objective was to conduct an in silico analysis of whole blood transcriptomes from SCA patients and healthy controls obtained from public repositories. We aimed to identify alterations in the adaptive immune system and validate these findings in our own SCA patient cohort. Bioinformatic analyses unveiled significant transcriptional alterations in B-cell signatures, developmental pathways, and signaling pathways. These results were validated in peripheral blood mononuclear cells from our SCA patient cohort and controls using real-time polymerase chain reaction and flow cytometry. Ninety genes exhibited differential expression, with 70 upregulated and 20 downregulated. Dysregulation in the B-cell compartment of SCA patients was evident, characterized by increased frequencies of immature and naive B-cells, and decreased percentages of memory B-cell subsets compared with healthy controls. Our findings highlight previously unexplored transcriptional and quantitative alterations in peripheral B-cells among SCA patients. Understanding these changes sheds light on the mechanisms contributing to the heightened infection risk in this population. Future studies should delve deeper into these molecular changes to develop targeted interventions and therapeutic strategies aimed at mitigating infection susceptibility in individuals with SCA., Competing Interests: Conflicts of Interest Disclosure The authors have nothing to disclose., (Copyright © 2024 International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.)

Background/objectives: Sickle cell anemia (SCA) is marked by hypoxia, inflammation, and secondary iron overload (IO), which potentially modulate hepcidin, the pivotal hormone governing iron homeostasis. The aim was to evaluate the iron incorporation in red blood cells (RBC) in SCA pediatric patients, considering the presence or absence of IO., Subjects/methods: SCA children (n = 12; SCA total ) ingested an oral stable iron isotope ( 57 Fe) and iron incorporation in RBC was measured after 14 days. Patients with ≥1000 ng/mL serum ferritin were considered to present IO (SCAio+; n = 4) while the others were classified as being without IO (SCAio-; n = 8). Liver iron concentration (LIC) was determined by Magnetic Resonance Imaging (MRI) T2* method., Results: The SCAio+ group had lower iron incorporation (mean ± SD: 0.166 ± 0.04 mg; 3.33 ± 0.757%) than SCAio- patients (0.746 ± 0.303 mg; 14.9 ± 6.05%) (p = 0.024). Hepcidin was not different between groups. Iron incorporation was inversely associated with serum ferritin level (SCA total group: r = -0.775, p = 0.041; SCAio- group: r = -0.982; p = 0.018) and sickle hemoglobin (HbS) presented positive correlation with iron incorporation (r = 0.991; p = 0.009) in SCAio- group. LIC was positively associated with ferritin (SCA total : r = 0.921; p = 0.026) and C reactive protein (SCAio+: r = 0.999; p = 0.020)., Conclusion: SCAio+ group had lower iron incorporation in RBC than SCAio- group, suggesting that they may not need to reduce their intake of iron-rich food, as usually recommended. Conversely, a high percentage of HbS may indirectly exacerbate hypoxia and seems to increase iron incorporation in RBC., Trial Registration: This trial was registered at www.ensaiosclinicos.gov.br . Identifier RBR-4b7v8pt., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Purpose: Identify the presence of a dysfunctional electroencephalographic (EEG) pattern in individuals with sickle cell disease (SCD) and hip osteonecrosis, and assess its potential associations with depression, anxiety, pain severity, and serum levels of brain-derived neurotrophic factor (BDNF)., Methods: In this cross-sectional investigation, 24 SCD patients with hip osteonecrosis and chronic pain were matched by age and sex with 19 healthy controls. Resting-state EEG data were recorded using 32 electrodes for both groups. Power spectral density (PSD) and peak alpha frequency (PAF) were computed for each electrode across Delta, Theta, Alpha, and Beta frequency bands. Current Source Density (CSD) measures were performed utilizing the built-in Statistical nonparametric Mapping Method of the LORETA-KEY software., Results: Our findings demonstrated that SCD individuals exhibited higher PSD in delta and theta frequency bands when compared to healthy controls. Moreover, SCD individuals displayed increased CSD in delta and theta frequencies, coupled with decreased CSD in the alpha frequency within brain regions linked to pain processing, motor function, emotion, and attention. In comparison to the control group, depression symptoms, and pain intensity during hip abduction were positively correlated with PSD and CSD in the delta frequency within the parietal region. Depression symptoms also exhibited a positive association with PSD and CSD in the theta frequency within the same region, while serum BDNF levels showed a negative correlation with CSD in the alpha frequency within the left insula., Conclusion: This study indicates that individuals with SCD experiencing hip osteonecrosis and chronic pain manifest a dysfunctional EEG pattern characterized by the persistence of low-frequency PSD during a resting state. This dysfunctional EEG pattern may be linked to clinical and biochemical outcomes, including depression symptoms, pain severity during movement, and serum BDNF levels., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

In children with sickle cell disease (SCD), splenectomy is immediately beneficial for acute sequestration crises and hypersplenism (ASSC/HyS) but portends a long-term risk of asplenia-related complications. We retrieved peripheral and splenic red blood cells (RBCs) from 17 SCD children/teenagers undergoing partial splenectomy for ASSC/HyS, 12 adult subjects without RBC-related disease undergoing splenectomy (controls), five human spleens perfused ex vivo with Hb SS - and Hb AA -RBC, and quantified abnormal RBC by microscopy, spleen-mimetic RBC filtration, and adhesion assays. Spleens were analyzed by immunohistochemistry and transmission electron microscopy (TEM). In circulating blood of SCD and control subjects, dysmorphic (elongated/spherocytic) RBCs were <2%, while proportions of pocked-RBC were 4.3-fold higher in SCD children than in controls. Compared to controls, splenic RBCs were more frequently dysmorphic (29.3% vs. 0.4%), stiffer (42.2% vs. 12.4%), and adherent (206 vs. 22 adherent RBC/area) in SCD subjects. By TEM, both polymer-containing and homogenous RBC contributed to spleen congestion, resulting in 3.8-fold higher RBC population density in SCD spleens than in control spleens, predominantly in the cords. Perfused spleens with normal function displayed similar congestion and retention of dysmorphic RBC as SCD spleens. The population density of active macrophages was similar in SCD and control spleens, with a relative deficit in phagocytosis of polymer-containing RBC. Despite the existence of hyposplenism, splenectomy in SCD children removes an organ that still efficiently filters out potentially pathogenic altered RBC. Innovative treatments allowing fine-tuned reduction of RBC retention would alleviate spleen congestion, the major pathogenic process in ASSC/HyS, while preserving spleen protective functions for the future., (© 2024 The Author(s). American Journal of Hematology published by Wiley Periodicals LLC.)

Patients with sickle cell disease (SCD) exhibit high levels of reactive oxygen species and low plasma levels of lipophilic antioxidants, which may contribute to end-organ damage and disease sequelae. Apolipoprotein A1, the major apolipoprotein of high-density lipoprotein (HDL), is mainly secreted by the intestine and liver in the form of monomeric ApoA1 (mApoA1) present in plasma. Cholesterol and α-tocopherol are delivered to ApoA1 via the ATP-binding cassette transporter, subfamily A, member 1 (ABCA1). We measured cholesterol, mApoA1, ApoA1, and lipophilic antioxidants in the plasma of 17 patients with SCD and 40 healthy volunteers. Mean HDL cholesterol (-C) levels in SCD patients and healthy subjects were 59.3 and 48.1 mg/dL, respectively, and plasma lutein, zeaxanthin, and α-tocopherol were 64.0%, 68.7%, and 9.1% lower, respectively. To compare SCD to healthy subjects with similar HDL-C, we also performed subgroup analyses of healthy subjects with HDL-C above or below the mean. In SCD, the mApoA1 level was 30.4 μg/mL; 80% lower than 141 μg/mL measured in healthy volunteers with similar HDL-C (56.7 mg/dL). The mApoA1 level was also 38.4% greater in the higher versus lower HDL-C subgroups (p = .002). In the higher HDL-C subgroup, lutein and zeaxanthin transported by HDL were 48.9% (p = .01) and 41.9% (p = .02) higher, respectively, whereas α-tocopherol was 31.7% higher (p = .003), compared to the lower HDL-C subgroup. Plasma mApoA1 may be a marker of the capacity of HDL to capture and deliver liposoluble antioxidants, and treatments which raise HDL may benefit patients with high oxidative stress as exemplified by SCD., (© 2024 Hartis‐Pharma SA, European Journal of Haematology published by John Wiley & Sons Ltd.)

Abstract: Etavopivat is an investigational, once daily, oral, selective erythrocyte pyruvate kinase (PKR) activator. A multicenter, randomized, placebo-controlled, double-blind, 3-part, phase 1 study was conducted to characterize the safety and clinical activity of etavopivat. Thirty-six patients with sickle cell disease (SCD) were enrolled into 4 cohorts: 1 single-dose, 2 multiple ascending doses, and 1 open-label (OL). In the OL cohort, 15 patients (median age 33.0 years [range, 17-55]) received 400 mg etavopivat once daily for 12 weeks; 14 patients completed treatment. Consistent with the mechanism of PKR activation, increases in adenosine triphosphate and decreases in 2,3-diphosphoglycerate were observed and sustained over 12 weeks' treatment. This translated clinically to an increase in hemoglobin (Hb; mean maximal increase 1.6 g/dL [range, 0.8-2.8]), with >1 g/dL increase in 11 (73%) patients during treatment. In addition, the oxygen tension at which Hb is 50% saturated was reduced (P = .0007) with a concomitant shift in point of sickling (P = .0034) to lower oxygen tension in oxygen-gradient ektacytometry. Hemolysis markers (absolute reticulocyte count, indirect bilirubin, and lactate dehydrogenase) decreased from baseline, along with matrix metalloproteinase-9 and erythropoietin. In the OL cohort, adverse events (AEs) were mostly grade 1/2, consistent with underlying SCD; 5 patients had serious AEs. Vaso-occlusive pain episode was the most common treatment-emergent AE (n = 7) in the OL cohort. In this, to our knowledge, the first study of etavopivat in SCD, 400 mg once daily for 12 weeks was well tolerated, resulting in rapid and sustained increases in Hb, improved red blood cell physiology, and decreased hemolysis. This trial was registered at www.ClinicalTrials.gov as #NCT03815695., (© 2024 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Sickle cell diseases (SCD) are the most common genetic disorders with significant morbidity and mortality worldwide, including in India. The high prevalence of this disorder in many geographical regions calls for the use of a point-of-care rapid diagnostic test (RDT) for early screening and management of the diagnosed cases to reduce the allied clinical severity. In view of this, the present study was undertaken for the validation of a point-of-care RDT kit (SICKLECHECKTM) for the screening of SCD. This validation and diagnostic accuracy study was conducted among the cases advised for screening of SCD. For validation, all the recruited cases were investigated for both the SICKLECHECKTM RDT kit and HPLC (Variant-II) considering HPLC as a gold standard. A total of 400 cases were screened for both tests. For the presence and absence of sickle cell hemoglobin in the samples, SICKLECHECKTM RDT kit results showed a sensitivity and specificity of 99.39% and 98.73% respectively with references to HPLC findings. For the detection of the 'AS' pattern, the SICKLECHECKTM RDT kit has shown a sensitivity and specificity of 99.07% and 98.81% respectively. For the detection of the 'SS' pattern, the SICKLECHECKTM RDT kit has shown a sensitivity and specificity of 97.92% and 100.0% respectively. Cases with β thalassemia trait, hemoglobin E trait, hemoglobin Lepore trait and trait for hereditary-persistence-of-fetal-hemoglobin (high HbF %) diagnosed in HPLC were resulted with 'AA' pattern in SICKLECHECKTM RDT kit. The high sensitivity and specificity of the SICKLECHECKTM RDT kit insist on its use as a point-of-care screening tool for SCD especially where there is a lack of laboratory facilities as well as in hospital-based set-up requiring immediate diagnosis and management of SCD. However, for further confirmation, the samples should be analyzed with other gold standard techniques like HPLC., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Purohit et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The production of HbS - an abnormal hemoglobin (Hb) - in sickle cell disease (SCD) results in poorly deformable red blood cells (RBCs) that are prone to microcapillary occlusion, causing tissue ischemia and organ damage. Novel treatments, including gene therapy, may reduce SCD morbidity, but methods to functionally evaluate RBCs remain limited. Previously, we presented the microfluidic impedance red cell assay (MIRCA) for rapid assessment of RBC deformability, employing electrical impedance-based readout to measure RBC occlusion of progressively narrowing micropillar openings. We describe herein the design, development, validation, and clinical utility of the next-generation MIRCA assay, featuring enhanced portability, rapidity, and usability. It incorporates a miniaturized impedance analyzer and features a simplified wash-free operation that yields an occlusion index (OI) within 15 min as a new metric for RBC occlusion. We show a correlation between OI and percent fetal hemoglobin (%HbF), other laboratory biomarkers of RBC hemolysis, and SCD severity. To demonstrate the assay's versatility, we tested RBC samples from treatment-naïve SCD patients in Uganda that yielded OI levels similar to those from hydroxyurea (HU)-treated patients in the U.S., highlighting the role of %HbF in protecting against microcapillary occlusion independent of other pharmacological effects. The MIRCA assay could also identify a subset of HU-treated patients with high occlusion risks, suggesting that they may require treatment adjustments including a second-line therapy to improve their outcomes. This work demonstrates the potential of the MIRCA assay for accelerated evaluation of RBC health, function, and therapeutic effect in an ex vivo model of the microcapillary networks., Competing Interests: Declaration of competing interest U. A. Gurkan and Case Western Reserve University have financial interests in Hemex Health Inc. and BioChip Labs Inc. M. A. Suster, U. A. Gurkan, P. Mohseni, and Case Western Reserve University have financial interests in XaTek Inc. U. A. Gurkan has financial interests in DxNow Inc. P. Mohseni has financial interests in Haima Therapeutics LLC. Financial interests include licensed intellectual property, stock ownership, research funding, employment, consulting fees, and royalties during the conduct of this study. The competing interests of Case Western Reserve University employees are overseen and managed by the Conflict of Interests Committee according to a Conflict-of-Interest Management Plan. S. Oshabaheebwa, C. A. Delianides, A. A. Patwardhan, E. N. Evans, Z. Sekyonda, A. Bode, F. M. Apio, C. K. Mutuluuza, and V. A. Sheehan report no conflict., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Historically understudied and regarded as a mild type of sickle cell disease, HbSC can be associated with significant, progressive complications. Prospective studies are urgently needed to address treatment gaps for HbSC disease. Commentary on: Nelson et al. The clinical spectrum of HbSC sickle cell disease-not a benign condition. Br J Haematol 2024;205:653-663., (© 2024 The Author(s). British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Sickle cell disease (SCD)-associated chronic hemolysis promotes oxidative stress, inflammation, and thrombosis leading to organ damage, including liver damage. Hemoglobin scavenger receptor CD163 plays a protective role in SCD by scavenging both hemoglobin-haptoglobin complexes and cell-free hemoglobin. A limited number of studies in the past have shown a positive correlation of CD163 expression with poor disease outcomes in patients with SCD. However, the role and regulation of CD163 in SCD-related hepatobiliary injury have not been fully elucidated yet. Here we show that chronic liver injury in SCD patients is associated with elevated levels of hepatic membrane-bound CD163. Hemolysis and increase in hepatic heme, hemoglobin, and iron levels elevate CD163 expression in the SCD mouse liver. Mechanistically we show that heme oxygenase-1 (HO-1) positively regulates membrane-bound CD163 expression independent of nuclear factor erythroid 2-related factor 2 (NRF2) signaling in SCD liver. We further demonstrate that the interaction between CD163 and HO-1 is not dependent on CD163-hemoglobin binding. These findings indicate that CD163 is a potential biomarker of SCD-associated hepatobiliary injury. Understanding the role of HO-1 in membrane-bound CD163 regulation may help identify novel therapeutic targets for hemolysis-induced chronic liver injury.

Little is known about the impact of vitamin D supplementation on hand grip strength (HGS) and health-related quality of life (HRQoL) in children and adolescents with sickle cell disease (SCD). We aimed to evaluate the safety and efficacy of monthly high-dose vitamin D 3 supplementation and its implications on bone mineral density (BMD), HGS, and HRQoL in patients with SCD and healthy controls. The study included 42 children with SCD and 42 healthy matched controls. The study participants were supplemented with high-dose monthly oral vitamin D 3 . Changes in the serum level of 25(OH) vitamin D 3 , maximum HGS, and BMD from baseline to 6 months were assessed, and the HRQoL questionnaire and Childhood Health Assessment Questionnaire (CHAQ) were used to evaluate the functional capacity. At baseline, SCD subjects had poorer growth status indicated by negative Z scores. Suboptimal BMD was detected by significantly lower Z score, and lower HGS and worse HRQL parameters were found compared to the controls (P < 0.001). Median 25(OH) vitamin D 3 was significantly lower in SCD patients compared to controls (16.5 vs. 28 ng/mL, respectively (P < 0.001)). After 6 months of vitamin D supplementation, there was significant improvement in the DEXA Z-score (P < 0.001), limitation of physical health (P = 0.02), pain scores (P < 0.001), and CHAQ grades (P = 0.01) in SCD patients. A significant improvement in HGS (P < 0.001 and P = 0.005) as well as the CHAQ score (P < 0.001 and P = 0.003) was detected in the SCD group and controls, respectively. There were no reported clinical adverse events (AEs) or new concomitant medications (CMs) during the study duration, and safe levels of Ca and 25 (OH) D3 were observed at 3 and 6 months for both groups. There was a significant positive correlation between HGS and total physical score (r = 0.831, P < 0.001) and a negative correlation with CHAQ score (r =  - 0.685, P < 0.001). We also detected a significant positive correlation between vitamin D levels at 6 months and HGS (r = 0.584, P < 0.001), pain score (r = 0.446, P < 0.001), and a negative correlation with CHAQ score (r =  - 0.399, P < 0.001).   Conclusion: Monthly oral high-dose vitamin D supplementation was safe and effective in improving vitamin D levels, HGS, and HRQoL in SCD children and healthy subjects, and BMD scores in SCD patients. Further randomized controlled trials are warranted to assess an optimal dosing strategy and to investigate the impact on clinically significant outcomes in children and adolescents with SCD and their healthy counterparts.   Trial registration: ClinicalTrials.gov , identifier NCT06274203, date of registration: 23/02/2024, retrospectively registered. What is known: • Several studies have reported a high prevalence of vitamin D deficiency and suboptimal bone mineral density (BMD) in sickle cell disease (SCD) patients. • Musculoskeletal dysfunction is reported in SCD patients with a negative impact on physical activity and health-related quality of life (HRQL). • Little is known regarding the impact of vitamin D3 supplementation in children and adolescents with SCD. What is new: • We found that monthly oral high-dose vitamin D3 supplementation was safe, tolerated, and effective in improving serum vitamin D levels, HGS, BMD scores, and HRQL in SCD patients., (© 2024. The Author(s).)

We compared serum anti-Mullerian hormone (AMH) levels in women with sickle cell disease (SCD) (n = 152) to those of Black comparison women (n = 128) between the ages of 20 and 45 years and evaluated the impact of hydroxyurea (HU) and iron overload on ovarian reserve in those with SCD. SCD treatment was abstracted from medical records. Linear regression models were fit to examine the relationship between log(AMH) and SCD, adjusting for age. The analysis was repeated to account for HU use (current, previous, never) and iron overload (ferritin ≥1000 ng/mL vs. <1000 ng/mL). AMH estimates among women with SCD were lower than those among comparison women (2.23, 95% confidence interval [CI] 1.80-2.76 vs. 4.12, 95% CI 3.11-5.45, respectively). Women with SCD who were currently using HU had 63% lower (95% CI 43-76) AMH values than comparison women; those with SCD with prior or no HU use also had lower AMH estimates than comparison women, but the difference was less pronounced. There were no differences in predicted AMH values among women with SCD for those with and without iron overload. Women with SCD and low AMH may have a shorter reproductive window and may benefit from referral to a reproductive specialist., (© 2024 British Society for Haematology and John Wiley & Sons Ltd.)

Abstract: Chronic kidney disease (CKD) is a major contributor to morbidity and mortality in sickle cell disease (SCD). Anemia, induced by chronic persistent hemolysis, is associated with the progressive deterioration of renal health, resulting in CKD. Moreover, patients with SCD experience acute kidney injury (AKI), a risk factor for CKD, often during vaso-occlusive crisis associated with acute intravascular hemolysis. However, the mechanisms of hemolysis-driven pathogenesis of the AKI-to-CKD transition in SCD remain elusive. Here, we investigated the role of increased renovascular rarefaction and the resulting substantial loss of the vascular endothelial protein C receptor (EPCR) in the progressive deterioration of renal function in transgenic SCD mice. Multiple hemolytic events raised circulating levels of soluble EPCR (sEPCR), indicating loss of EPCR from the cell surface. Using bone marrow transplantation and super-resolution ultrasound imaging, we demonstrated that SCD mice overexpressing EPCR were protective against heme-induced CKD development. In a cohort of patients with SCD, plasma sEPCR was significantly higher in individuals with CKD than in those without CKD. This study concludes that multiple hemolytic events may trigger CKD in SCD through the gradual loss of renovascular EPCR. Thus, the restoration of EPCR may be a therapeutic target, and plasma sEPCR can be developed as a prognostic marker for sickle CKD., (© 2024 American Society of Hematology. Published by Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.)

Introduction: Transfusion has a central place in the treatment of patients with sickle cell disease (SCD). Matching blood groups of red blood cell (RBC) units with the blood groups of the patient is essential to prevent alloimmunization and delayed hemolytic transfusion reaction. African ancestry donors have the best phenocompatibility with patients of the same origin, however their RBCs may present characteristic that can alter quality of the unit such as glucose-6-phosphate dehydrogenase (G6PD) deficiency. The objective is to analyze transfusion protocol, immunization rate and mismatch situations of SCD recipients and to evaluate the frequency of G6PD deficiency in RBCs units from African ancestry donors., Methods: Samples of units transfused to SCD patients were analyzed. Transfusion data were collected from institutional databases. The activity of G6PD was measured in the segment of the RBC units., Results: A total of 98 segments of units transfused to 37 SCD recipients in 41 transfusions episodes was collected. Among patients, 35.1% (n = 13) had no antibodies; 10.8% (n = 4) had antibodies against Fy a /Fy b , Jk a /Jk b , M/N, S/s; 21.6% (n = 8) against RH/K antigens. In all cases, the protocols were in line with the recommendations. G6PD deficiency was observed in 9 units, that were all collected from Afro-Caribbean donors., Conclusion: The transfusion protocol is established to prevent immunological reactions due to disparities in blood group antigens between donors and SCD recipients. However, the units of African ancestry donors, which allowed the best compatibility, displayed a high rate of G6PD deficiency. The storage and recovery impact of this deficiency must be evaluated., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Société française de transfusion sanguine (SFTS). Published by Elsevier Masson SAS. All rights reserved.)

Mitapivat, a pyruvate kinase activator, shows great potential as a sickle cell disease (SCD)-modifying therapy. The safety and efficacy of mitapivat as a long-term maintenance therapy are currently being evaluated in two open-label studies. Here we applied a comprehensive multi-omics approach to investigate the impact of activating pyruvate kinase on red blood cells (RBC) from 15 SCD patients. HbSS patients were enrolled in one of the open-label, extended studies (NCT04610866). Leukodepleted RBC obtained from fresh whole blood at baseline, prior to drug initiation, and at longitudinal timepoints over the course of the study were processed for multi-omics through a stepwise extraction of metabolites, lipids and proteins. Mitapivat therapy had significant effects on the metabolome, lipidome and proteome of SCD RBC. Mitapivat decreased 2,3-diphosphoglycerate levels, increased adenosine triphosphate levels, and improved hematologic and sickling parameters in patients with SCD. Agreement between omics measurements and clinical measurements confirmed the specificity of mitapivat on targeting late glycolysis, with glycolytic metabolites ranking as the top correlates to parameters of hemoglobin S oxygen affinity (p50) and sickling kinetics (t50) during treatment. Mitapivat markedly reduced levels of proteins of mitochondrial origin within 2 weeks of initiation of treatment, with minimal changes in reticulocyte counts. In the first 6 months of treatment there were also transient elevations of lysophosphatidylcholines and oxylipins with depletion of free fatty acids, suggestive of an effect on membrane lipid remodeling. Multi-omics analysis of RBC identified benefits for glycolysis, as well as activation of the Lands cycle.

The degree of anaemia in sickle cell disease (SCD) is a well-known contributor to morbidity and mortality. We aimed to explore the factors affecting haemoglobin (Hb) level in African SCD patients, considering haemolysis biomarkers (LDH and bilirubin level, and reticulocyte count), leucocyte and platelet counts and socio-demographic characteristics (gender, age group, country of residence and BMI). The research was part of the CADRE multinational cohort and involved 3699 SCD patients living in Mali, Senegal, Ivory Coast, Democratic Republic of Congo, Gabon and Cameroon: 2936 SS/Sβ0, 587 SC and 176 Sβ + patients with median Hb level of 8, 11.3 and 11.2 g/dL respectively (p < 0.001). In multivariate analysis conducted in 1394 SS/Sβ0 patients, living in Cameroon, female gender, lower BMI, higher haemolysis markers (especially LDH) and higher leucocyte and platelet counts were independently associated with lower Hb level (all p < 0.05). In 497 SC and 156 Sβ + patients, female gender (p < 0.001), lower BMI (p < 0.05) and higher platelet counts (p < 0.001) were independently associated with lower Hb level. Anaemia in African SCD patients is not only associated with haemolysis but also with the country of residence, lower BMI and leucocyte or platelet counts which might reflect inflammation related to infectious burden in the region., (© 2024 The Author(s). British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Introduction: There is a wide range of clinical manifestations in sickle cell disease (SCD). Despite having the same condition, each person's response to disease complications differs greatly. Individuals can be categorized according to the severity of their diseases to determine which group they fall into and receive the appropriate care based on their needs. The relationship between fetal hemoglobin (HbF), lactate dehydrogenase (LDH), and disease severity in Tanzania is little understood. This investigation sought to ascertain the relationship between HbF, LDH, and disease severity in SCD patients at the Bugando Medical Center., Method: This cross-sectional study was carried out on SCD patients aged 6 months and older at the Bugando Medical Center in Mwanza, Tanzania. A total of 130 SCD patients were enrolled. The clinical history and laboratory test results for SCD patients were recorded on a specially constructed patient report form., Results: The majority of participants (56.9%) were men. For the population under study, more than half (60.8%) of participants had a moderate clinical phenotype (MCP), followed by 31.5% of asymptomatic participants and 7.7% of people with severe clinical phenotypes (SCP). Participants with SCP had substantially higher levels of LDH, with a mean level of 810.97IU/L (95% CI: 559.31-1062.64) and a p-value of 0.005. The severe clinical phenotype exhibited a significantly higher mean HbF score value of 10.09% (95% CI: 7.44-13.74%) with a p-value of 0.024 when compared to the asymptomatic and moderate clinical phenotypes., Conclusion: In SCD patients with SCP compared to ACP and MCP, the HbF levels were higher, but did not show a protective effects, and LDH can be used to predict the severity of SCD., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Kahema et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Genome-Wide Association Studies (GWASs) have identified a huge number of variants associated with different traits. However, their validation through in vitro and in vivo studies often lags well behind their identification. For variants associated with traits or diseases of biomedical interest, this gap delays the development of possible therapies. This issue also impacts beta-hemoglobinopathies, such as beta-thalassemia and sickle cell disease (SCD). The definitive cures for these diseases are currently bone marrow transplantation and gene therapy. However, limitations regarding their effective use restrict their worldwide application. Great efforts have been made to identify whether modulators of fetal hemoglobin (HbF) and, to a lesser extent, hemoglobin A2 (HbA 2 ) are possible therapeutic targets. Herein, we performed the post-GWAS in vivo validation of two genes, cyclin D3 ( CCND3 ) and nuclear factor I X ( NFIX ), previously associated with HbF and HbA 2 levels. The absence of Ccnd3 expression in vivo significantly increased g (HbF) and d (HbA 2 ) globin gene expression. Our data suggest that CCND3 is a possible therapeutic target in sickle cell disease. We also confirmed the association of Nfix with γ-globin gene expression and present data suggesting a possible role for Nfix in regulating Kruppel-like transcription factor 1 ( Klf1 ), a master regulator of hemoglobin switching. This study contributes to filling the gap between GWAS variant identification and target validation for beta-hemoglobinopathies.

Primum non nocere! Can iron deficiency, an abnormality that causes anemia, benefit people with sickle cell disease (SCD) who already have an anemia? The published literature we review appears to answer this question in the affirmative: basic science considerations, animal model experiments, and noncontrolled clinical observations all suggest a therapeutic potential of iron restriction in SCD. This is because SCD's clinical manifestations are ultimately attributable to the polymerization of hemoglobin S (HbS), a process strongly influenced by intracellular HbS concentration. Even small decrements in HbS concentration greatly reduce polymerization, and iron deficiency lowers erythrocyte hemoglobin concentration. Thus, iron deficiency could improve SCD by changing its clinical features to those of a more benign anemia (i.e., a condition with fewer or no vaso-occlusive events). We propose that well-designed clinical studies be implemented to definitively determine whether iron restriction is a safe and effective option in SCD. These investigations are particularly timely now that pharmacologic agents are being developed, which may directly reduce red cell hemoglobin concentrations without the need for phlebotomies to deplete total body iron., (© 2024 The Authors. American Journal of Hematology published by Wiley Periodicals LLC.)

Objective: Sickle cell disease (SCD) is a common hereditary hemoglobin disorder worldwide. One of the main treatments for patients with SCD is the requirement for blood transfusions. Posttransfusion alloimmunization with red blood cell (RBC) antigens continues to be a major risk factor for SCD. The objective of this study was to determine the rate, nature, and risk factors of red cell alloimmunization among pediatric patients with SCD in our center and compare our results with published reports from Saudia Arabia SA, regional countries, and some international countries., Materials and Methods: A retrospective chart review of patients with SCD at King Abdulaziz Medical City-Jeddah, between 2008 and 2019 was performed. Demographic characteristics and transfusion histories were recorded. Blood samples were analyzed for alloimmunization using immunohematologic techniques., Results: In total, 121 patients were analyzed. Alloantibodies were detected in 21 patients (17.4%) and were mostly single in 15 patients (71.4%), anti-K (23.7%), anti-E (19.0%), and anti-S (9.5%). The other 6 patients (28.6%) had multiple alloantibodies, especially the combination of anti-C and anti-K (9.5%) and the combination of anti-C and anti-E (9.5%). Alloantibody levels were significantly higher in patients with frequent hospital admissions (>5 times annually), those who had an exchange blood transfusion, those younger than 3 years old, and those who received a larger number of blood units ( P ≤0.05)., Conclusion: The rate of RBC alloimmunization is determined and considered relatively low compared with that in other nations. Matching for extended RBC antigens to include ABO, RH (D, C, c, E, e), K, Fy a , Fy b , Jk a , and Jk b antigens in the screening panel for donors and recipients is highly recommended to ensure better transfusion practices and avoid transfusion-related complications., Competing Interests: The authors declare no conflict of interest., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Sickle cell anaemia (SCA) patients display elevated levels of circulating pro-inflammatory cytokines and endothelial activation markers compared to healthy peers. The impact of exercise on the pro-inflammatory state in SCA remains unclear. This study aimed to characterize the whole-blood transcriptome profile in response to an acute bout of exercise in paediatric SCA patients. Twenty-three SCA participants (13 ± 3 years, 52% girls) and 17 healthy controls (14 ± 3 years, 29% girls) performed eight 2-min bouts of cycle ergometry interspersed with 1-min rest intervals. Whole-blood transcriptome profile (RNA-seq) was performed before and after exercise. At baseline, gene pathways associated with gas transport in erythrocytes were up-regulated in SCA patients compared to controls. Following exercise, gene pathways associated with innate immunity were altered in both groups. Interaction analyses revealed 160 annotated genes (101 up- and 59 down-regulated) that differentially altered by exercise in SCA patients. Moreover, genes that exhibited a blunted response to exercise in SCA patients were enriched in the IL-17 signalling pathway, suggesting an impaired innate immune response to exercise. This data will contribute to the development of evidence-based exercise prescription guidelines for this patient population., (© 2024 The Author(s). British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Background: The sporadic nature of blood transfusion therapy coupled with the alteration of HAMP genes may exacerbate the risk of iron burden in sickle cell anaemia (SCA) patients. The study determined the polymorphic distribution of the HAMP promoter gene rs10421768 and hepcidin levels in SCA patients., Method: Sixty participants aged ≥12years [45 SCA patients and 15 controls (HbA)] were recruited from 15th March, 2023 to 20th July, 2023 for a case-control study at Methodist Hospital Wenchi, Ghana. Complete blood count and hepcidin levels assessment were done using haematology analyzer and ELISA, respectively. Genomic DNA was extracted using the Qiagen Kit, and HAMP gene rs10421768 (c.-582 A>G) was sequenced using the MassARRAY method. Data were analysed using SPSS version 26.0., Results: The frequencies of the HAMP promoter rs10421768 genotypes AA, AG, and GG were 64.4%, 33.3%, and 2.2% in SCA patients, and 86.7%, 13.3%, and 0% in the controls, respectively. Serum hepcidin levels were significantly higher among controls than cases [204.0 (154.1-219.3) vs 150.2 (108.1-195.6)μg/L, p<0.010]. Participants with HAMP rs10421768 homozygous A genotype had higher serum levels of hepcidin compared with those in the wild genotypes (AG/GG) group [(188.7 (130.9-226.9) vs 136.8 (109.7-157.8)μg/L, p<0.016]. Disease severity and blood cell parameters were not associated with the HAMP variants (p>0.05)., Conclusion: The HAMP promoter rs10421768 AA genotype has the highest frequency of distribution and the GG genotype with the least distribution. Participants with HAMP rs10421768 G allele (c.-582A>G) had reduced levels of hepcidin. HAMP rs10421768 genotypes had no association with blood cell parameters and disease severity. The HAMP rs10421768 genotypes may influence serum levels of hepcidin. Further study is required to elucidate the potential effect of the G allele on hepcidin transcription., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Appiah et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Drepanocytosis is a genetic disease relevant for its epidemiological, clinical and socio-economic aspects. In our country the prevalence is highly uneven with peaks in former malaria areas, but migration flows in recent years have led to significant changes. In this document we review the screening programs currently existing in Italy with particular emphasis on newborn screening, which in other countries around the world, including within Europe, is at most universal and mandatory. The essential laboratory issues are reviewed, from sampling aspects (cord blood or peripheral), to the analytical (analytical methods dedicated to neonatal screening and adult carrier detection) and post analytical (reporting, informative) ones. An economic analysis based on data collected in the province of Modena is also proposed, clearly showing that neonatal screening is also beneficial from an economic point of view., (© 2024 Walter de Gruyter GmbH, Berlin/Boston.)

Background: Sickle cell disease (SCD) is a major heritable genetic disease in sub-Saharan Africa, including Mauritania. Fetal hemoglobin (HbF) can affect the pathophysiology, moderate the clinical course, and offer prospects for curative treatment of SCD. This study aimed to investigate the influence of single nucleotide polymorphisms (SNPs) in the BCL11A gene on the levels of HbF and hematological parameters in Mauritanian sickle cell ( HbSS ) patients., Methods: Complete blood count was assessed in 565 patients suspected to have SCD. Polymerase chain reaction (PCR)-restriction fragment length polymorphism was performed to identify the HbSS , and sequencing was used for genotyping three SNPs: rs4671393 ( A>G ) and rs11886868 ( C>T ) in the intron 2 and rs1052520 ( G>A ) in the 3'UTR regions of the BCL11A gene in 50 sickle cell patients., Results: The prevalence of HbSS among the study population was 8.8% (50/565), and the mean (± standard deviation) of HbF level was 15.0% (± 6.0%). Sequencing showed the presence of three genotypes: AA (13.6%), AG (46.6%), GG (39.6%) in rs4671393; CC (17.6%), CT (48.7%), and TT (33.6%) in rs11886868 . All samples from HbSS individuals displayed a wild-type genotype in the rs1052520 allele. The prevalence of minor alleles A ( rs4671393 ) and C ( rs11886868 ) were 37% and 39%, respectively. There was a statistically significant association ( p = 0.034) between rs4671393 SNP and elevated HbF (mean 12.72 ± 6.26%)., Conclusions: The study of three SNPs in the BCL11A locus in Mauritanian patients with SCD showed a significant association of rs4671393 allele with the HbF level. Further research is needed to explore additional SNPs in the BCL11A locus and investigate other genetic markers reported to modulate HbF levels, such as HBS1L-MYB and Xmn1-HBG2 , to improve the management of this potentially life-threatening condition in Mauritania., Competing Interests: The authors declare no conflict of interest., (© 2024 The Author(s). Published by IMR Press.)

Background: Thrombin is a critical protease modulating thrombosis as well as inflammation, which are one of the main pathophysiological mechanisms in sickle vasculopathy, and its levels were reported to be high in sickle cell disease (SCD). The thrombin-thrombomodulin complex activates the TAFI inhibitor of fibrinolysis, which acts by reducing plasmin affinity for its substrate thus hindering fibrinolysis., Objective: We aimed to determine the influence of the Thr325Ile single nucleotide polymorphism (SNP) on TAFI antigen levels and potential effects on the severity of SCD in a cohort of Egyptian patients., Methods: Genotyping of Thr325lle polymorphism using Taq-Man SNP genotyping assay and TAFI level measurement using an enzyme-linked immunosorbent assay were performed for 80 SCD patients (45 homozygous HbSS, 16 S/β 0 and 19 Sβ + ) as well as 80 age- and gender-matched healthy control subjects., Results: Plasma TAFI levels were higher in SCD patients with Thr325Ile polymorphism, yet the difference was not statistically significant (p = .204). SCD patients with polymorphic genotypes had a greater number of hospital admissions (p = .03). Ten patients with acute chest syndrome had the homozygous polymorphic genotype (GG), and all patients with pulmonary hypertension had the polymorphic genotype (six were homozygous [GG] and five were heterozygous [GA]). Patients with SCD complicated with pulmonary hypertension showed significantly higher plasma TAFI levels (p = .044)., Conclusion: The analysis of Thr325Ile polymorphisms combined with plasma TAFI levels suggests that the analyzed SNP could influence plasma TAFL levels and SCD disease severity and hospitalization rates, which could be predictors for complex disease., (© 2024 Wiley Periodicals LLC.)