bims-sicedi 2025-01-05 papers

Stem Cell Res Ther. 2024 Dec 31. 15(1): 504

Enhanced fetal hemoglobin production via dual-beneficial mutation editing of the HBG promoter in hematopoietic stem and progenitor cells for β-hemoglobinopathies.

Prathibha Babu Chandraprabha, Manoj Kumar K Azhagiri, Vigneshwaran Venkatesan, Wendy Magis, Kirti Prasad, Sevanthy Suresh, Aswin Anand Pai, Srujan Marepally, Alok Srivastava, Kumarasamypet Murugesan Mohankumar, David I K Martin, Saravanabhavan Thangavel.

BACKGROUND: Sickle cell disease (SCD) and β-thalassemia patients with elevated gamma globin (HBG1/G2) levels exhibit mild or no symptoms. To recapitulate this natural phenomenon, the most coveted gene therapy approach is to edit the regulatory sequences of HBG1/G2 to reactivate them. By editing more than one regulatory sequence in the HBG promoter, the production of fetal hemoglobin (HbF) can be significantly increased. However, achieving this goal requires precise nucleotide conversions in hematopoietic stem and progenitor cells (HSPCs) at therapeutic efficiency, which remains a challenge.
METHODS: We employed Cas9 RNP-ssODN-mediated homology-directed repair (HDR) gene editing to mimic two naturally occurring HBG promoter point mutations; -175T > C, associated with high HbF levels, and -158 C > T, a common polymorphism in the Indian population that induces HbF under erythropoietic stress, in HSPCs.
RESULTS: Asymmetric, nontarget ssODN induced high rates of complete HDR conversions, with at least 15% of HSPCs exhibiting both the -175T > C and -158 C > T mutations. Optimized conditions and treatment with the small molecule AZD-7648 increased this rate, with up to 57% of long-term engrafting human HSPCs in NBSGW mice containing at least one beneficial mutation. Functionally, in vivo erythroblasts exhibited high levels of HbF, which was sufficient to reverse the cellular phenotype of β-thalassemia. Further support through bone marrow MSC co-culture boosted complete HDR conversion rates to exceed 80%, with minimal InDels, improved cell viability, and induced fetal hemoglobin levels similar to those of Cas9 RNP-mediated indels at BCL11A enhancer and HBG promoter.
CONCLUSIONS: Cas9 RNP-ssODN-based nucleotide conversion at the HBG promoter offers a promising gene therapy approach to ameliorate the phenotypes of β-thalassemia and SCD. The developed approach can simplify and broaden applications that require the cointroduction of multiple nucleotide modifications in HSPCs.

Keywords: Gene therapy; Hematopoietic stem cells; Homology-directed gene editing; Single-stranded oligonucleotides; β-hemoglobinopathies

DOI: https://doi.org/10.1186/s13287-024-04117-0

Br J Haematol. 2025 Jan 01.

Plasma inflammatory and angiogenic protein profiling of patients with sickle cell disease.

L A de Ligt, A E Gaartman, K Konté, S Thakoerdin, K Fijnvandraat, T W Kuijpers, R van Bruggen, B J Biemond, E Nur.

In this study, we aimed to explore the inflammatory and angiogenic pathways in sickle cell disease (SCD). We used proximity extension assay technology (Olink) to measure 92 plasma proteins involved in inflammation and angiogenesis. Plasma samples were collected from 57 SCD patients (sickle cell anaemia/HbS-β0 thalassaemia-thalassaemia) in steady-state and 13 healthy ethnicity-matched healthy controls (HCs). From 15 patients, paired samples were collected during both steady-state and vaso-occlusive episodes (VOEs) and from 23 SCD patients longitudinal samples were collected before and after treatment with either voxelotor (n = 10), hydroxyurea (n = 8) or allogeneic haematopoietic stem-cell transplantation (n = 5). Fifty plasma proteins were differentially expressed in steady-state SCD patients as compared to HC. These included proteins involved in angiogenesis (i.e. ANGPT1, ANGPT2 and VEGFA), the IL-18 signalling pathway (i.e. IL-6, IL-10, IL-18), T-cell activation (i.e. LAG3, PDCD1) and natural killer (NK)-cell activation (CD244, NCR1, GZMB). While proteins involved in angiogenesis and the IL-18 signalling pathway were further upregulated during VOE, levels of several proteins involved in the IL-18 pathway, T-cell and NK-cell activation and angiogenesis, restored towards levels detected in HCs after curative or disease-modifying treatment. These findings might contribute to a better understanding of SCD pathophysiology and identifying potential new targets for therapeutic interventions.

Keywords: angiogenesis; inflammation; proteomics; sickle cell disease

DOI: https://doi.org/10.1111/bjh.19970

Front Mol Biosci. 2024 ;11 1481441

Circulating biomarkers associated with pediatric sickle cell disease.

Cecilia Elorm Lekpor, Felix Abekah Botchway, Adel Driss, Alaijah Bashi, Afua D Abrahams, Kwadwo Asamoah Kusi, Godfred Futagbi, Ernest Alema-Mensah, William Agbozo, Wesley Solomon, Adriana Harbuzariu, Andrew A Adjei, Jonathan K Stiles.

Introduction: Sickle cell disease (SCD) is a genetic blood disorder caused by a mutation in the HBB gene, which encodes the beta-globin subunit of hemoglobin. This mutation leads to the production of abnormal hemoglobin S (HbS), causing red blood cells to deform into a sickle shape. These deformed cells can block blood flow, leading to complications like chronic hemolysis, anemia, severe pain episodes, and organ damage. SCD genotypes include HbSS, HbSC (HbC is an abnormal variant of hemoglobin), and HbS/β-thalassemia. Sickle cell trait (SCT), HbAS, represents the carrier state, while other hemoglobin variants include HbCC, HbAC, and the normal HbAA. Over 7.5 million people worldwide live with SCD, with a high mortality rate in sub-Saharan Africa, including Ghana. Despite its prevalence, SCD is underdiagnosed and poorly managed, especially in children. Characterized by intravascular hemolysis, SCD leads to oxidative stress, endothelial activation, and systemic inflammation. Identifying circulating blood biomarkers indicative of organ damage and systemic processes is vital for understanding SCD and improving patient management. However, research on biomarkers in pediatric SCD is limited and few have been identified and validated. This study explores specific circulating biomarkers in pediatric SCD in Ghana (West Africa), hypothesizing that inflammatory and neuronal injury markers in children with SCD could predict disease outcomes.
Methods: Clinical data were collected from 377 children aged 3-8 years with various Hb genotypes, including SCD and SCT, at Korle-Bu Teaching Hospital in Accra, Ghana (2021-2022). A total of 80 age- and sex-matched subjects were identified. A cross-sectional study utilized a multiplexed immunoassay procedure to evaluate serum biomarkers, including cytokines, chemokines, vascular injury markers, systemic inflammation markers, cell-free heme scavengers, brain-derived neurotrophic factor (BDNF), and angiogenic factors.
Results: Elevated levels of BDNF, Ang-2, CXCL10, CCL11, TNF-α, IL-6, IL-10, IL12p40, ICAM-1, VCAM-1, Tie-2, and VEGFA were observed in HbSS subjects, correlating with hemoglobin level, leukocyte, and erythrocyte counts. Heme scavengers like HO-1, hemopexin, and haptoglobin also correlated with these parameters. ROC and AUC analyses demonstrated the potential of these biomarkers in predicting SCD outcomes.
Conclusion: These findings suggest that there are significant differences between biomarker expression among the different genotypes examined. We conclude that a predictive algorithm based on these biomarkers could be developed and validated through longitudinal assessment of within-genotype differences and correlation of the data with disease severity or outcomes. With such a tool one can enhance SCD management and improve patient outcomes. This approach may pave the way for personalized interventions and better clinical care for pediatric SCD patients.

Keywords: global health; hemoglobinopathies; inflammation biomarkers; oxidative stress; pediatric hematology

DOI: https://doi.org/10.3389/fmolb.2024.1481441

Eur J Haematol. 2025 Jan 02.

The Mortality of Adults With Sickle Cell Disease at a Comprehensive Sickle Cell Center.

Jennifer A Afranie-Sakyi, Eldrida Randall, Ross Fasano, Morgan L McLemore, Fuad El Rassi.

INTRODUCTION: Sickle cell disease (SCD) is the most common hemoglobinopathy in North America. The life expectancy of SCD has extended into adulthood with screenings, preventative care, and hydroxyurea. However, comorbidities arise as adults with SCD age, leading to early mortality.
METHODS: We conducted a retrospective chart review of the Georgia Comprehensive Sickle Cell Center at Grady Health System, analyzing records of deceased SCD patients from 2013 to 2020.
RESULTS: Amongst the 72 patients analysed, majority had severe complications from SCD and at least 1 cardiovascular comorbidity. The median age of death was 44 (STD = 15.5) for all genotypes with the median age of death at 39 (STD = 14.26) for SS and Sβ0 genotypes (n = 51). There was no difference in the median age of death for patients who maintained regular clinic visits (a visit in the last 6 months prior to death) compared to those who did not. Despite hydroxyurea's known benefits in reducing SCD morbidity and mortality, less than 50% of patients had a prescription.
CONCLUSION: As new therapies are approved, their impact on SCD-related morbidity and mortality must be evaluated. Improving access to, and education about, disease-modifying therapies like hydroxyurea for both patients and clinicians is essential to improving outcomes.

Keywords: end organ damage; hydroxyurea; life expectancy; mortality; sickle cell disease

DOI: https://doi.org/10.1111/ejh.14360

Int J Gen Med. 2024 ;17 6487-6493

Web-Based Educational Resources for Patients with Sickle Cell Disease: Availability and Reliability.

Dalal Mahmoud Alabdulmohsen, Sarah Khalid Alfuhaydi, Abdullah Mohamed Al Saloum, Bayan Alomair, Mohannad Yousuf Alhindi, Ruba Yosof Alsulami, Mortadah Hadi Alsalman.

Purpose: Arabic is the primary language used in the Middle East, where sickle cell disease (SCD) is prevalent. This study aims to quantify Arabic web educational materials for patients with SCD and provide a descriptive standardized assessment.
Methods and Materials: This retrospective, descriptive study aimed to analyze Arabic websites on SCD through the Discern instrument and JAMA benchmark.
Results: We evaluated the quality and reliability of 27 Arabic SCD-related websites. Regarding website content, all 27 (100%) defined sickle cell disease, whereas 25 (96.30%) and 24 (92.59%) illustrated its manifestations and treatments, respectively. However, only 12 (44.44%) discussed the prevention of the disease through premarital genetic screening and counseling. According to the Discern score, 11 (40.74%) websites were of low quality, while 16 (59.26%) were of moderate quality. On the other hand, the JAMA score reveals that only 2 (7.41%) websites were high reliability, while the majority 25 (92.59%) were low reliability. Additionally, analysis revealed a weak positive correlation between the Discern and JAMA scores (correlation coefficient of 0.19). There were no statistically significant differences in the Discern and JAMA scores between websites on the first page of the search results and those on other pages (p = 0.941 and 0.359, respectively).
Conclusion: Empowering patients with comprehensive knowledge about various disease aspects is a pivotal component in the effective management of SCD and, consequently, improving its outcomes. Regrettably, there is a notable scarcity of credible and high-quality written web-based health resources available in Arabic despite significant advancements in other clinical aspects of SCD. Augmenting the existing online resources in Arabic patients' native language could yield substantial enhancements in patient care across various dimensions.

Keywords: Arabic language; education; sickle cell disease

DOI: https://doi.org/10.2147/IJGM.S495248