Source Of Hematopoietic Stem Cells Research Articles

Tracing embryonic hematopoiesis guides induction of pluripotent stem cells to hematopoietic progenitors

In this issue of Developmental Cell, Fowler etal. applied genetic lineage-tracing mouse models to support the notion that artery endothelial cells are the predominant source of hematopoietic stem cells. They leveraged this and developed a method capable of efficiently differentiating human pluripotent stem cells into HLF+HOXA+ hematopoietic progenitors.

The Ethical Challenges of Umbilical Cord Blood Stem Cell Banking: A Qualitative Study

Background: Umbilical cord blood serves as a potent source of hematopoietic stem cells, utilized in treating specific diseases and preserved in blood banks. Objectives: This study aims to explore the ethical issues associated with these repositories. Methods: This qualitative research involved conducting 14 interviews with experts and the families of recipients or donors of umbilical cord blood. Participants were selected purposefully from May to November 2021. Results: The investigation identified five principal ethical challenges: presentation of information, interpersonal relationships among involved parties, respect for human dignity, adherence to rules and regulations, and the handling of tissue samples. These challenges encompassed various categories and subcategories, including informed consent, communication and advertising of information, financial considerations, conflicts of interest, professional interactions, ownership rights concerning the child and parents, privacy and confidentiality issues, compliance with regulations and guidelines, and the clinical and research uses of the tissue samples. Conclusions: The study unveiled significant ethical concerns in the domain of umbilical cord blood stem cell banking. Addressing these ethical dilemmas necessitates the involvement of health policymakers and medical ethics experts, along with a comprehensive understanding of these banks' multifaceted nature by the community.

Evaluation of Circulating Endothelial Cells as Direct Marker of Endothelial Damage in Allo-Transplant Recipients at High Risk of Hepatic Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome

Sinusoidal obstruction syndrome (SOS), also known as veno-occlusive disease (VOD), is a rare but potentially fatal complication following allogenic hematopoietic cell transplantation (allo-HCT). Timely identification of SOS/VOD to allow for prompt treatment is critical, but identifying a VOD-predictive biomarker remains challenging. Given the pivotal role of endothelial dysfunction in SOS/VOD pathophysiology, the CECinVOD study prospectively evaluated levels of circulating endothelial cells (CECs) in patients undergoing allo-HCT with a myeloablative conditioning (MAC) regimen to investigate the potential of CEC level in predicting and diagnosing SOS/VOD. A total of 150 patients from 11 Italian bone marrow transplantation units were enrolled. All participants were age >18 years and received a MAC regimen, putting them at elevated risk of developing SOS/VOD. Overall, 6 cases of SOS/VOD (4%) were recorded. CECs were detected using the Food and Drug Administration-approved CellSearch system, an immunomagnetic selection-based platform incorporating ferrofluid nanoparticles and fluorescent-labeled antibodies, and were defined as CD146+, CD105+, DAPI+, or CD45-. Blood samples were collected at the following time points: before (T0) and at the end of conditioning treatment (T1), at neutrophil engraftment (T2), and at 7 to 10 days postengraftment (T3). For patients who developed VOD, additional samples were collected at any suspected or proven VOD onset (T4) and weekly during defibrotide treatment (T5 to T8). A baseline CEC count >17/mL was associated with an elevated risk of SOS/VOD (P = .04), along with bilirubin level >1.5 mg/mL and a haploidentical donor hematopoietic stem cell source. Postconditioning regimen (T1) CEC levels were elevated (P = .02), and levels were further increased at engraftment (P < .0001). Additionally, patients developing SOS/VOD after engraftment, especially those with late-onset SOS/VOD, showed a markedly higher relative increase (>150%) in CEC count. Multivariate analysis supported these findings, along with a high Endothelial Activation and Stress Index (EASIX) score at engraftment (T2). Finally, CEC kinetics corresponded with defibrotide treatment. After the start of therapy (T4), CEC levels showed an initial increase in the first week (T5), followed by a progressive decrease during VOD treatment (T6 and T7) and a return to pre-SOS/VOD onset levels at resolution of the complication. This prospective multicenter study reveals a low incidence of SOS/VOD in high-risk patients compared to historical data, in line with recent reports. The results from the CECinVOD study collectively confirm the endothelial injury in allo-HCT and its role in in the development of SOS/VOD, suggesting that CEC level can be a valuable biomarker for diagnosing SOS/VOD and identifying patients at greater risk of this complication, especially late-onset SOS/VOD. Furthermore, CEC kinetics may support treatment strategies by providing insight into the optimal timing for discontinuing defibrotide treatment.

Transplantation of hematopoietic progenitors in myelofibrosis.

The objective of this work is to generate recommendations on the management of allogeneic stem cell transplantation (allo-SCT) in primary myelofibrosis (PMF). A comprehensive systematic review of articles published between 1999 and 2015 (January) was used as a source of scientific evidence. The recommendations were produced through a Delphi process involving a panel of 23 experts appointed by the European LeukemiaNet and the European Blood and Marrow Transplantation Group. Key questions included patient selection, donor selection, pre-transplant management, conditioning regimen, post-transplant management, prevention, and management of post-transplant relapse. Patients with intermediate-2 or high-risk disease and age < 70 years should be considered candidates for allo-SCT. Patients with intermediate-risk 1 disease and age < 65 years should be considered candidates if they have refractory transfusion-dependent anemia, or a peripheral blood (PB) blast percentage > 2%, or adverse cytogenetics. Splenectomy before transplantation must be decided on a case-by-case basis. Patients with intermediate-2 or high-risk disease who lack a human leukocyte antigen (HLA)-matched sibling or unrelated donor should be enrolled in a protocol that uses HLA non-identical donors. PB was considered the most appropriate source of hematopoietic stem cells for transplants from HLA-matched unrelated donors and siblings. The optimal intensity of the conditioning regimen has yet to be defined. Strategies such as discontinuation of immunosuppressive drugs, infusion of donor lymphocytes, or both were considered adequate to prevent clinical relapse. In conclusion, we provide consensus-based recommendations aimed at optimizing allo-SCT in PMF. Unmet clinical needs were highlighted.

Perspectives for the Use of Umbilical Cord Blood in Transplantation and Beyond: Initiatives for an Advanced and Sustainable Public Banking Program in Greece.

The umbilical cord blood (UCB) donated in public UCB banks is a source of hematopoietic stem cells (HSC) alternative to bone marrow for allogeneic HSC transplantation (HSCT). However, the high rejection rate of the donated units due to the strict acceptance criteria and the wide application of the haploidentical HSCT have resulted in significant limitation of the use of UCB and difficulties in the economic sustainability of the public UCB banks. There is an ongoing effort within the UCB community to optimize the use of UCB in the field of HSCT and a parallel interest in exploring the use of UCB for applications beyond HSCT i.e., in the fields of cell therapy, regenerative medicine and specialized transfusion medicine. In this report, we describe the mode of operation of the three public UCB banks in Greece as an example of an orchestrated effort to develop a viable UCB banking system by (a) prioritizing the enrichment of the national inventory by high-quality UCB units from populations with rare human leukocyte antigens (HLA), and (b) deploying novel sustainable applications of UCB beyond HSCT, through national and international collaborations. The Greek paradigm of the public UCB network may become an example for countries, particularly with high HLA heterogeneity, with public UCB banks facing sustainability difficulties and adds value to the international efforts aiming to sustainably expand the public UCB banking system.

Impact of COVID-19 pandemic on cord blood banking and transplantation.

Umbilical cord blood is a rich source of hematopoietic stem cells that has been used for transplantation for over 30 years, especially when there is no compatible hematopoietic stem cell donor available. Its use has decreased more recently, since the development of methods to improve haploidentical transplants has allowed the use of mobilized peripheral blood as a source of hematopoietic stem cells. Public cord blood banks collect, process and store cord blood samples from voluntary donations. In addition, many public banks are involved in research to enhance hematopoietic stem cell therapies and develop new treatments for haematological and genetic diseases. The COVID-19 pandemic, which emerged in 2019, has had a profound and wide-ranging impact on human health and treatment. The area of hematopoietic stem cell transplantation was deeply affected by reductions in bone marrow, peripheral blood and cord blood donations; logistical challenges; exposure of healthcare workers and other challenges. The present study reviews the impact of the COVID-19 pandemic on cord blood banking and transportation around the world with a special focus on Brazil.

In vitro differentiation of human CD45+ CD34+ induced hematopoietic progenitor cells from iPSCs using a monolayer system

Hematopoietic stem cells (HSCs) represent crucial target cells in the management of hematopoietic and immune system disorders. Unfortunately, the primary source of hematopoietic stem cells is limited. Hematopoietic stem cells derived from induced pluripotent stem cells (iPSCs) hold great promise for applications in cell therapy, disease modeling, and drug screening. To achieve a consistent induction method, one specific induction scheme capable of reliably generating CD34 and CD45 double-positive cells from iPSCs was optimized, employing a comparative analysis and screening of various induction methods. The comprehensive induction procedures are outlined in this document.

FLT3-Ligand Alone Enables the Identification and Maintenance in Vitro of Viable Quiescent Human Fetal Liver Hematopoietic Stem Cells with Maintenance of Their Function

Cells with sustained multi-lineage blood cell regenerative potential are referred to as hematopoietic stem cells (HSCs). Current findings indicate that they are responsible for lifelong blood production, are first detected within the first month of development in humans and are largely created prior to birth after which they expand their numbers in response to physiological demands for normal or enhanced blood cell output requirements. Interestingly, a number of the intrinsically determined functional properties of HSCs also change after birth. These include an apparent decline in their self-renewal potential. Thus, for example, in humans as in mice, cells with long-term (&amp;gt;6 month) HSC regenerative properties present in the developing fetal liver (FL) are a source of HSCs that possess a much higher in vivo regenerative capability than those from older donor sources, such as adult bone marrow or even cord blood (CB). Accordingly, it has been of longstanding interest to better understand the molecular regulation of this high regenerative capacity prevalent in fetal HSCs for potential future therapeutic as well as scientific exploitation. Here, we describe the results of experiments designed to answer the hypothesis that human FL HSCs with human-relevant self-renewal properties can be isolated as a quiescent CD49f+ subset of the GPI80+CD90+CD38-CD45RA-CD34+CD45+ population following their incubation in standard serum-free culture medium supplemented with FLT3-ligand (FLT3-L) alone. Initial experiments showed expression of the CD49f integrin on first trimester hFL cells selectively depleted cells able to produce colonies of granulocytes, macrophages or erythroid cells in standard 2-week methylcellulose cultures containing SCF, GM-CSF, IL6, IL3 and EPO. Conversely, expression of the CD49f integrin selectively enriched for cells with 12-week output capabilities in both growth factor (GF)-supplemented stromal co-cultures and in sublethally irradiated, transplanted immunodeficient NOD-Rag1 -/-IL2Rγc -/- W 41/41 (NRG-W) mice. Initial experiments designed to test the effect of multiple GF and small molecule additives on the maintenance over a 7-day period of this in vivo regenerative ability of the input FL HSC confirmed GPI80 expression to be a continuing positive selective phenotype. In addition, the result of transplant experiments showed that a 2-day incubation in FLT3-L alone maintained the 12-week serially transplantable activity of the HSCs (12-weeks/cycle) as fully equivalent to the unmanipulated input cells and significantly superior (P&amp;lt;0.05) to FLT3-L+IL3+SF (3GF) with or without addition of UM171, stemregenin, or eltrombopag. Interestingly, in vitro monitoring of GPI80+ cells showed FLT3-L alone maintained the survival of only 20% of the input GPI80+ cells compared to any of the 3GF-based conditions. In addition, the time to complete a first division and subsequent divisions of the input cells was delayed and prolonged, respectively, in the FLT3-L versus the 3GF conditions. Subsequent 7-day suspension cultures and 6-week GF-supplemented stromal co-cultures experiments have confirmed the existence of a G0 population within the HSC-enriched subset of human FL cells that best maintains their growth potential in FLT3-L alone. Together, these results demonstrate CD49f expression to be a pervasive marker of human HSCs throughout development and reveal the importance of different GF conditions to support the maintenance of viability and retention of self-renewal capability of human fetal HSCs in contrast to those required to activate/support a rapid initiation of cell division. These findings set the stage for future development of strategies to exploit human FL cells therapeutically and may also be critical to designing conditions that will best support the ex vivo maintenance of HSCs at and after birth.

Unrevealing Hematopoietic Reconstruction Discrepancies after Allo-UCBT and Allo-PBSCT at Single Cell Resolution

Umbilical cord blood (UCB) and G-CSF mobilizing peripheral blood stem cell (G-PBSC) are the main sources of hematopoietic stem cells for transplantation on clinic. Clinical data have shown that hematopoietic reconstruction in allogeneic cord blood transplantation (allo-UCBT) is significantly delayed compared with allogeneic peripheral blood stem cell transplantation (allo-PBSCT), suggesting that the cellular composition and reconstruction dynamics of UCB are significantly different from that of G-PBSC. Following on the heels of our recently study that found HSC/MPPs show differentiation bias to megakaryocytic-erythroid lineage and strong proliferation tendency, and defined a neutrophil progenitor population named S100A hi Neu2 which is inversely associated with the incidence of GVHD after allo-PBSCT (Yingying Huo et al, Science Immunology 2023), we next aimed to analyze the differences of hematopoietic reconstitution between allo-UCBT and allo-PBSCT and the causes of delayed hematopoietic reconstitution after allo-UCBT. In this study, we collected peripheral blood (PB) and bone marrow (BM) samples from 8 patients with bone marrow failure syndrome (BMFs) who received allo-UCBT (n=4) or allo-PBSCT (n=4) at different time points (d14, d21, d30, d60, d90, d180, d365) after transplantation. At the same time, UCB, G-PBSC and BM of normal children were collected as controls. Lin -CD34 + cells from BM, G-PBSC and UCB were separated by FACS for STRT-seq, the total nucleated cells (TNCs) of all samples were isolated for 10X transcriptome sequencing. We used 276628 hematopoietic cells to map the single cell transcriptome profiles of hematopoietic reconstruction by different transplantation methods and annotated 44 cell types. Compared with the G-PBSC, the immunogenicity of HSC/MPPs in Lin -CD34 + cells derived from UCB decreased, the proportion increased, and the differentiation bias of HSC/MPPs to monocytic and erythroid lineage was stronger, but the differentiation ability to myeloid and megakaryocytic lineage was decreased, the proportion of EBM, MEP and CMP decreased. For TNCs, the proportion of T cells and NK cells increased, and NK_CD56dim_CD16 had a stronger immune function. Compared with allo-PBSCT, the differentiation of HSC/MPPs and CMP into neutrophils in the early stage after allo-UCBT was weakened. The proportion of MEP cells decreased, and the differentiation ability of HSC/MPPs to MEP, HSC/MPPs and MEP to Mk was weakened. In summary, we found that the delayed reconstruction of neutrophils and platelets in patients with allo-UCBT are related to the nature of the graft, suggesting the importance of reasonable intervention of HSC derived from UCB to accelerate platelet implantation.

Constructing a Machine Learning-Based Rating Model to Predict the Outcome of GCSF Mobilization of Hematopoietic Stem Cells in Peripheral Blood

Objective Peripheral blood stem cells serve as the primary source of hematopoietic stem cells for both autologous and allogeneic stem cell transplantation. Granulocyte colony-stimulating factor (G-CSF) stands as the most commonly employed mobilizing agent in clinical practice. While the majority of donors receiving G-CSF mobilization demonstrate high mobilization efficiency, there remains a subset of donors who fail to yield a sufficient quantity of hematopoietic stem cells. Inefficient mobilization not only leads to wastage of valuable resources but also significantly impacts transplant outcomes for recipients. Therefore, addressing the challenges associated with predicting mobilization outcomes, optimizing donor selection strategies, and further enhancing mobilization approaches is of paramount importance. Methods In this study, we conducted a retrospective analysis of mobilization data from 1008 donors who underwent hematopoietic stem cell mobilization using G-CSF at the Bone Marrow Transplantation Center, the First Affiliated Hospital, Zhejiang University School of Medicine, over the past 5 years. We meticulously examined the correlation between mobilization outcomes (quantified by the quantity of collected CD34+ cells) and various factors, including mobilizing agent usage, demographic data, complete blood count, and blood biochemistry. Furthermore, we harnessed the power of machine learning algorithms, such as linear regression, decision tree, and AdaBoost, to develop a robust scoring model capable of predicting mobilization outcomes. The primary objective of this model is to furnish a predictive tool for assessing mobilization outcomes with accuracy and precision. Results (1) Prior to receiving G-CSF, several factors exhibited a significant positive correlation with the quantity of CD34+ cells in the collection: donor's body weight (R=0.37, p&amp;lt;0.001), peripheral blood leukocytes (R=0.24, p&amp;lt;0.001), hemoglobin (R=0.23, p&amp;lt;0.001), monocytes (R=0.22, p&amp;lt;0.001), lymphocytes (R=0.18, p&amp;lt;0.001), platelets (R=0.18, p&amp;lt;0.001), red blood cells (R=0.12, p&amp;lt;0.001), neutrophils (R=0.15, p&amp;lt;0.001), hematocrit (R=0.21, p&amp;lt;0.001), mean corpuscular-hemoglobin concentration (R=0.15, p&amp;lt;0.001), low-density lipoprotein (R=0.11, p&amp;lt;0.01), albumin (R=0.09, p&amp;lt;0.05), ferritin (R=0.19, p&amp;lt;0.001), triglycerides (R=0.17, p&amp;lt;0.001), creatinine (R=0.17, p&amp;lt;0.001), and uric acid (R=0.29, p&amp;lt;0.001). (2) Age exhibited a significant negative correlation with the quantity of collected CD34+ cells in the collection (R=-0.11, p&amp;lt;0.001). (3) When the total dose of G-CSF administration was fixed, mobilization with twice-daily dosing yielded superior results compared to once-daily dosing (collected CD34+ cell count: 1268/μl vs. 1044/μl, p&amp;lt;0.001). (4) The ratio of G-CSF dosage to body weight demonstrated a significant negative correlation with the quantity of CD34+ cells (R=-0.09, p&amp;lt;0.01). Mobilization with a ratio of 6-7 μg/kg/day showed better results compared to a ratio of 7-12 μg/kg/day (p=0.07). (5) A scoring model was developed using machine learning methods to predict the mobilization outcomes of donors. Validation on the test dataset exhibited a high predictive ability of the model (AUC&amp;gt;0.7). Conclusion This study provides valuable insights for selecting hematopoietic stem cell donors and serves as a reference for future strategies aimed at improving mobilization outcomes. The identified factors, such as donor weight, peripheral blood parameters, G-CSF dosing regimen, and the ratio of dosage to body weight, can be considered when selecting donors and optimizing mobilization protocols. By incorporating machine learning techniques, a scoring model was developed, demonstrating a high predictive ability that can assist in forecasting mobilization outcomes for potential donors. These findings contribute to the optimization of donor selection and mobilization strategies.

Impact of COVID-19 in Thalassemia Patients Undergoing Hematopoietic Stem Cell Transplant Recipients

Objective: This article primarily examines the clinical attributes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in transplant recipients with thalassemia, offering significant insights into the treatment and care of this patient population. Method: The present study retrospectively analyzed the data of all thalassemia patients who underwent Hematopoietic stem cell transplantation (HSCT) at the First Affiliated Hospital of Guangxi Medical University between December 2019 and December 2022. A total of 280 patients were included, of which 81 had confirmed coronavirus disease 2019 (COVID-19). The study collected information on patient demographics, transplantation type and timing, graft-versus-host disease (GVHD), use of immunosuppressive agents, onset time and severity of COVID-19, and prognosis. Follow-up was conducted until March 31, 2023.Univariate analysis was performed using SPSS v25.0, and GraphPad Prism was used for the cumulative incidence comparisons. Results: The median age was 3.6(2-19) years.The main type of thalassemia was β type (93.9%). Identical sibling donors accounted for 40%, haploidentical donors accounted for 25.4%, and identical unrelated donors accounted for 34.6% (10/10). The main source of hematopoietic stem cells was bone marrow combined with peripheral blood (85%).There were no significant differences in age, gender, diagnosis, donor type, graft type, use of immunosuppressive agents, GVHD, and pneumonia of pro-COVID-19 between infected patients and non-infected patients with SARS-CoV-2. Most of the patients were mild (74 cases, 91.3%) in terms of the severity of COVID-19 infection, only 8.6% of the moderate cases, and none severe and died. 74 cases were cured without drug treatment. Of the seven patients treated with medications, four were azvudine and three were nematasvir. The median number of days (IQR) of treatment for COVID-19 was 5(5) days. The cumulative incidence in the immunosuppressive group was higher than that in the non-immunosuppressive group over the same time frame. There was no significant difference in the final infection rate of COVID-19 among patients receiving transplantation in different years(2020,2021,2022), which was 24.7 26.8 36.5 ( p=0.368), respectively. Conclusion: The low infection rate and no severe cases may be due to scientific protection and timely medication. There are no special risk factors for COVID-19 infection in thalassemia patients after transplantation.

309. Optimized hematopoietic stem cell source for the ex vivo production of mature human neutrophils as a potential cell-based therapy for neutropenia

Abstract Background Neutrophils or granulocytes are the most common innate immune cell and are critical for eliminating invasive pathogens. Patients with low neutrophil counts face an increased risk of fatal opportunistic infections. Allogeneic granulocyte transfusions offer a solution to supplement endogenous neutrophil counts but are challenging due to insufficient preservation methods and donation feasibility. Here, we compare the capacity of three different hematopoietic stem cell (HSC) sources; 1) cord blood (CB), 2) live adult bone marrow (LABM), and 3) cadaveric adult bone marrow (CABM), to expand and generate an ex vivo neutrophil source. Methods HSCs were expanded ex vivo with or without UM729 then differentiated and evaluated for neutrophil yield and purity. Ex vivo differentiated neutrophils were characterized by flow cytometry for activated phenotype surface markers. Finally, the functional capacity of ex vivo neutrophils, including phagocytosis, ectodomain shedding, and reactive oxygen species (ROS) production, was measured in response to the fungal pathogen Candida albicans. Results CB-derived HSCs were found to be superior in expansion capacity compared to LABM- or CABM-derived HSCs by 3-fold at day six. The use of UM729 reduced the purity of neutrophil differentiation by 44% for both live and deceased BM marrow-derived HSCs. UM729 had no observable effect on the purity of neutrophil differentiation for CB-derived HSCs. Additionally, due to enhanced Fc gamma receptor I expression, ex vivo neutrophils from all sources were ten times more sensitive to recognizing IgG-opsonized C. albicans than primary neutrophils. Ex vivo neutrophils were capable of phagocytosis, ROS production, and ectodomain shedding to a similar capacity as primary donor neutrophils. Conclusion We find that cadaveric bone marrow-derived HSCs are a viable source for HSC-generated neutrophils. That said, CB-derived HSC were superior in expansion capacity. We also highlight the unique opsonin-activating features of ex vivo generated neutrophils which warrant further study in granulocyte transfusion animal models of systemic infection. These data underscore the significance of neutrophil cellular therapeutics as a novel modality for preventing infection in high-risk neutropenic patients. Disclosures Nathan E. Jeffries, BA, Safi Biotherapeutics: Salary Michael Mansour, MD, PhD, Thermofisher: Grant/Research Support

Mesenchymal Stromal Cells from Perinatal Tissues as an Alternative for Ex Vivo Expansion of Hematopoietic Progenitor and Stem Cells from Umbilical Cord Blood.

Umbilical cord blood (UCB) serves as a source of hematopoietic stem and progenitor cells (HSPCs) utilized in the regeneration of hematopoietic and immune systems, forming a crucial part of the treatment for various benign and malignant hematological diseases. UCB has been utilized as an alternative HSPC source to bone marrow (BM). Although the use of UCB has extended transplantation access to many individuals, it still encounters significant challenges in selecting a histocompatible UCB unit with an adequate cell dose for a substantial proportion of adults with malignant hematological diseases. Consequently, recent research has focused on developing ex vivo expansion strategies for UCB HSPCs. Our results demonstrate that co-cultures with the investigated mesenchymal stromal cells (MSCs) enable a 10- to 15-fold increase in the cellular dose of UCB HSPCs while partially regulating the proliferation capacity when compared to HSPCs expanded with early acting cytokines. Furthermore, the secretory profile of UCB-derived MSCs closely resembles that of BM-derived MSCs. Moreover, both co-cultures exhibit alterations in cytokine secretion, which could potentially impact HSPC proliferation during the expansion process. This study underscores the fact that UCB-derived MSCs possess a remarkably similar supportive capacity to BM-derived MSCs, implying their potential use as feeder layers in the ex vivo expansion process of HSPCs.

Features of the leukocyte pool of umbilical cell blood cell concentrate prepared for long-term cryostorage

Allogeneic hematopoietic cell transplantation is the standard of care for patients with highrisk acute leukemia. Cord blood (UCB) is an alternative source of allogeneic hematopoietic stem cells for patients who need transplantation but do not have a related donor. The purpose of our study was to evaluate the characteristics of leukocyte pool (cellular composition, immunophenotype) of umbilical cord blood (UCB) cell concentrates, which were harvested for public long-term cryostorage for the needs of transplantology. A study of 1096 samples of umbilical cord blood of full-term newborns before and after processing [isolation of hematopoietic stem cells (HSC) concentrate] was carried out. The number of cells in the pooled concentrate of HSC at a volume of 25 mL, after long-term cryostorage was as follows: leukocytes, 17.41±0.36 × 108; HSCs with CD34+ immunophenotype, 5.25±3.6 × 106; natural killer cells (CD3-CD16+CD56+), 1.65+0.7 × 108. Analysis of the NKT cell population revealed 6.22±2.1% of cells with CD3+CD16/CD56+ immunophenotype. The contents of CD3+CD56+ cells was 2.69±2.4%, the relative amount of CD3+CD16+ was 2.53±1.2%. In the pooled NKT cell preparations, 5.15±2.1% of CD56+CD16 cells were detected, and two minor subpopulations were also identified, which differ in CD56 and CD16 antigen expression: the level of CD56-CD16+ was 2.91±1.2%, and the ratio of CD56+CD16+ cells was 0.69±0.3%. The obtained data on relative amounts and characteristics of cellular immunophenotype as well as the heterogeneity of the NK and NKT cell population in the HSC UCB concentrate, subjected to long-term cryostorage must be taken into account when selecting the HSC UCB concentrates for the purpose of transplantation in oncohematological diseases.

The effect of caffeine intake and passive smoking on umbilical cord blood unit's quality parameters.

Today cord blood (CB) is a valuable source of hematopoietic stem cells to treat many hematological disorders. One of the limitations of CB utilization is the reduced number of nucleated cells including stem cells. Therefore, CB banks around the world have developed strategies in an attempt to improve donor selection and the quality of the CB inventory. This study aimed to determine the impact of passive smoking and caffeine consumption on CB quality. CBs were obtained from mothers who gave birth at King Abdulaziz Medical City. All mothers gave their informed consent. Personal interviews about the mother's demographics, smoking status and exposure, and caffeine consumption executed, followed by a chart review to analyze maternal and neonatal factors. Laboratory testing was performed on all collected CB units. Using descriptive statistics, maternal and newborn factors were analyzed. T-test or Mann-Whitney U Test, as appropriate, for continuous variables analysis to study the effect of second hand smoking and coffee consumption for the primary outcome. Our study demonstrated a reduction in CB MNC, including lymphocytes, in caffeine consumers among pregnant donors, as well as a reduction in cell potency activities, including total CFU and BFU-E. The effect of passive cigarette smoking on the same cohort was insignificant. Outcome of this study will help in optimizing the quality and quantity of stem cell harvesting from CB to get the maximum benefit and such knowledge will raise the awareness among pregnant women.

Infections and risk factors for infection-related mortality after pediatric allogeneic hematopoietic stem cell transplantation in Mexico: A single center retrospective study.

To identify the type of infections and risk factors for infection-related mortality (IRM) after allogeneic hematopoietic stem cell transplantation (HSCT). Retrospective cohort study of patients <16 years of age treated in 2010-2019 was conducted. Unadjusted hazard ratios (HR) and adjusted hazard ratios (aHR) with 95% confidence intervals (95% CIs) were estimated using Cox regression. Cumulative incidence was calculated. Data for 99 pediatric patients were analyzed. The myeloablative conditioning was the most used regimen (78.8%) and the hematopoietic stem cell source was predominantly peripheral blood (80.8%). Primary graft failure occurred in 19.2% of patients. Frequency of acute graft-versus-host disease was 46.5%. Total of 136 infectious events was recorded, the most common of which were bacterial (76.4%) followed by viral infection (15.5%) and then fungal infection (8.1%). The best predictors for infection subtypes where the following: a) for bacterial infection (the age groups of 10.1-15 years: aHR = 3.33; 95% CI: 1.62-6.85 and. >15 years: aHR = 3.34; 95% CI: 1.18-9.45); b) for viral infection (graft versus host disease: aHR = 5.36; 95% CI: 1.62-17.68), however, for fungal infection statistically significant predictors were not identified. Related mortality was 30% (n = 12). Increased risk for infection-related mortality was observed in patients with unrelated donor and umbilical cord stem cells recipients (HR = 3.12; 95% CI: 1.00-9.85). Frequencies of infections and infection-related mortality appear to be similar to those reported. Unrelated donors and stem cells from umbilical cord recipients were associated with a high risk of mortality.

Abstract 17 Umbilical Cord Blood Collection. How Do Different Factors Affect CD45 Cell Viability in Our Experience?

Abstract Introduction Umbilical cord blood (UCB) is an important source of hematopoietic stem cells for transplantation in some hematological diseases. One of the main factors influencing sample quality and transplantation success, in addition to histocompatibility, is the number of viable CD34+ cells. Over the years, different factors that could directly affect viability have been studied and evaluated. It is important to be able to define favorable ranges for obtaining high viabilities and optimal samples for their use. Objectives The aim of our study is to evaluate the incidence of three factors temperature during transport, volume and time between collection and process of UCB over cellular viability previous to cryopreservation. Methods We analyzed 10483 UCB samples collected between 2018 and 2022. Cell viability values were analyzed in total CD45 using flow cytometry with 7-AAD and Annexin V. We evaluated the relationship between cell viability with the three factors mentioned above. Results We observed a tendency for viability to decrease as the blood volume collected decreases, and as the temperature and elapsed hours increase. In concordance, we found that viability is dependent on the 3 factors analyzed (p &amp;lt;&amp;lt;0.001), observing that its variability can be explained in 4% by the variation of elapsed hours as well as the collection volume, while temperature explains this variation in 1%. Discussion With our samples we can assume that the variations in the ranges analyzed would not affect them to a great extent, since they are not determinant for obtaining an average viability lower than that established as acceptable in our bank (75%). On the other hand, we also conclude that viability cannot be explained from the variation of a single factor, so it would be important to analyze the interactions between them. For the time being, and in order to improve the quality of the samples, we consider it necessary to emphasize the collection of a good volume of blood and the rapid transport of the samples for processing.

Abstract 12 Evaluating the Properties of the Donor to Determine the Quality of Cord Blood

Abstract Introduction Cord blood is a valuable source of hematopoietic stem cells (HSCs) that offer advantages over other sources, but the volume and the absolute number of stem cells in cord blood are limited. Objectives The study aimed to analyze the influence of the factors relating to mothers, babies, and collection on the quality of cord blood units before cryopreservation in Vinmec Tissue Bank, Vietnam. This provides a thorough insight into available predictors that can inform the potential recipients. Methods This study, conducted at Vinmec Tissue Bank in Vietnam between January 2019 and December 2021, collected, processed, and analyzed 2,668 cord blood samples. The study evaluated the impact of donor and collection factors, including maternal age, delivery mode, gestational age, infant weight, gender, blood group, geography, season, collection volume, viability, TNC, and CD34+ cell components on cord blood characteristics. Results Results showed that maternal age, gestational age, delivery mode, and infant weight significantly affected TNC and CD34+ cells, while infant gender only has a significant impact on TNC. Additionally, the collection features such as cord blood volume, geography, the season of delivery, and waiting time associated with cord blood outcomes. Discussion In virtue of its superior matching probability, lower incidence of GVHD, and reduced recurrence rates, cord blood is considered a favorable option for HSC transplantation. However, the limited number of HSCs available from cord blood for bigger patients can be addressed through global cooperation. The possibility of using multiple cord blood units for hematologic cancers has been made feasible through inter-unit HLA matching 29,30. As global cooperation between cord blood banks expands, there is a growing opportunity to find matching samples for recipients. Our large-scale analysis of cord blood throughout Vietnam has highlighted the significance of baby weight and volume in determining cord blood quality. This report represents the first-ever study in Asia to investigate the impact of geography and demography on cord blood. Further evaluation is necessary for a comprehensive understanding of these factors, which would enable more appropriate counseling for patients. Figure 1. Elements that impact the quality of hematopoietic stem cells in cord blood.

Accessory-cell-free differentiation of hematopoietic stem and progenitor cells into mature red blood cells

Background aimsThe culture and ex vivo engineering of red blood cells (RBCs) can help characterize genetic variants, model diseases, and may eventually spur the development of applications in transfusion medicine. In the last decade, improvements to the in vitro production of RBCs have enabled efficient erythroid progenitor proliferation and high enucleation levels from several sources of hematopoietic stem and progenitor cells (HSPCs). Despite these advances, there remains a need for refining the terminal step of in vitro human erythropoiesis, i.e., the terminal maturation of reticulocytes into erythrocytes, so that it can occur without feeder or accessory cells and animal-derived components. MethodsHere, we describe the near-complete erythroid differentiation of cultured RBCs (cRBCs) from adult HSPCs in accessory-cell-free and xeno-free conditions. ResultsThe approach improves post-enucleation cell integrity and cell survival, and it enables subsequent storage of cRBCs for up to 42 days in classical additive solution conditions without any specialized equipment. ConclusionsWe foresee that these improvements will facilitate the characterization of RBCs derived from gene-edited HSPCs.

Hematopoietic cell transplantation for telomere biology diseases: A retrospective single-center cohort study.

Telomere biology diseases (TBD) result from defective telomere maintenance, leading to bone marrow failure. The only curative treatment for aplastic anemia related to TBD is a hematopoietic cell transplant (HCT). Although reduced-intensity conditioning (RIC) regimens decrease transplant-related mortality, non-hematological phenotypes represent a major challenge and are associated with poor long-term follow-up outcomes. To describe the outcome of TBD patients transplanted for marrow failure. This is a retrospective, single-center study describing the outcomes of 32 consecutive transplants on 29 patients between 1993 and 2019. The median age at transplantation was 14 years (range, 3-30 years). Most patients received a RIC regimen (n = 28) and bone marrow (BM) from an unrelated donor (n = 16). Four patients received a haploidentical transplant. Chimerism was available for 27 patients with a median time to neutrophil recovery of 20 days (13-36 days). Primary graft failure occurred in one patient, whereas second graft failure occurred in two. Acute GVHD grade II-IV and moderate to severe chronic GVHD occurred in 22% of patients at risk. Fourteen patients were alive after HCT at the last follow-up (median, 6 years; 1.4-19 years). The 5-year overall survival was better after matched sibling donor (MSD) transplantation compared to other hematopoietic stem cell sources (88.9% vs. 47.7%; p = .05; CI = 95%). Overall, 15 patients died after HCT, most of them (n = 11) after the first year of transplant, due to non-hematological disease progression or complication of chronic GVHD. Hematopoietic cell transplantation is a potentially curative treatment option for TBD, nonetheless the poor outcome reflects the progression of non-hematologic disease manifestations, which should be considered when transplantation is indicated.