Umbilical cord blood transplantation: the first 25 years and beyond. Blood. 2013;122:491-498. [PMID: 23673863 DOI: 10.1182/blood-2013-02-453175]

Leptin receptor, a surface marker for a subset of highly engrafting long-term functional hematopoietic stem cells

The hematopoietic system is sustained by a rare population of hematopoietic stem cells (HSCs), which emerge during early embryonic development and then reside in the hypoxic niche of the adult bone marrow microenvironment. Although leptin receptor (Lepr)-expressing stromal cells are well-studied as critical regulators of murine hematopoiesis, the biological implications of Lepr expression on HSCs remain largely unexplored. We hypothesized that Lepr⁺HSCs are functionally different from other HSCs. Using in vitro and in vivo experimental approaches, we demonstrated that Lepr further differentiates SLAM HSCs into two distinct populations; Lepr⁺HSCs engrafted better than Lepr^-HSCs in primary transplant. Compared to Lepr^-LSK cells, Lepr⁺LSK cells were highly enriched for extensively repopulating and self-renewing HSCs. Molecularly, Lepr⁺HSCs were characterized by a pro-inflammatory transcriptomic profile enriched for Type-I Interferon and Interferon-gamma (IFN-γ) response pathways, which are known to be critical for the emergence of HSCs in the embryo. We conclude that although Lepr⁺HSCs represent a minor subset of HSCs, they are highly engrafting cells that possess embryonic-like transcriptomic characteristics, and that Lepr can serve as a reliable marker for functional long-term HSCs, which may have potential clinical applicability.

Optimizing BIO feeding strategy promotes ex vivo expansion of human hematopoietic stem and progenitor cells

Ex vivo expansion is critical in facilitating the application of hematopoietic/progenitor stem cells (HSPCs) for regenerative therapies. Wnt signaling is implicated in the expansion and self-renewal maintenance of HSPCs. However, a reasonable method to regulate Wnt signaling in ex vivo cultures to achieve robust expansion of HSPCs has not yet been investigated. Here, cord blood-derived CD34⁺ cells were cultured with the activator of Wnt signaling 6-bromoindirubin-3'-oxime (BIO) under the following conditions: vehicle control (group A); BIO was added to the culture on days 0, 4, and 7 (group B); and BIO was added to the culture on days 0 and 7 (group C). Initial BIO treatment promoted the expansion of CD34⁺ cells on day 4. However, BIO supplementation on days 0 and 4 in group B attenuated HSPC expansion on day 7, while enhancing the multilineage commit potential and secondary expansion ability of expanded CD34⁺ cells. Based on this finding, an optimized BIO feeding strategy (group C) was proposed to support substantial expansion of HSPCs. After 10 days of culture, the expansion fold of CD34⁺ cells was 28.70 ± 0.46-folds, which was significantly higher than group A (16.20 ± 0.72-folds, p < 0.05). Moreover, the optimized BIO feeding strategy achieved increased primitive HSPC expansion without the loss of biological functions. Mechanistically, the optimized BIO feeding strategy avoided the excessive activation of Wnt observed in group B while maintaining a moderate level of intracellular β-catenin. These results provide an experimental and theoretical basis for Wnt regulation in ex vivo culture process and a potential strategy to expand HSPCs for transplantation.

Cord-Blood Natural Killer Cell-Based Immunotherapy for Cancer

Natural killer (NK) cells are a predominant part of innate immune cells and play a crucial role in anti-cancer immunity. NK cells can kill target cells nonspecifically, and their recognition of target cells is not restricted by the major histocompatibility complex. NK cells also fight against tumor cells independently of antibodies and prior activation. Of note, umbilical cord blood (UCB) is a rich source of NK cells. Immunotherapies based on UCB-derived NK cells are becoming increasingly researched, and the investigations are producing encouraging results. In recent years, non-modified and modified UCB-derived NK cells have been successfully developed to fight against tumor cells. Herein, UCB-derived NK cell-based immunotherapy is a potential strategy for the treatment of cancer in the future. In this review, we focus on discussing the biological characteristics of UCB-derived NK cells and their application prospects in anti-tumor immunotherapy, including the latest preclinical and clinical researches.

The Binns Program for Cord Blood Research: A novel model of cord blood banking for academic biomedical research

Umbilical cord blood is an important graft source in the treatment of many genetic, hematologic, and immunologic disorders by hematopoietic stem cell transplantation. Millions of cord blood units have been collected and stored for clinical use since the inception of cord blood banking in 1989. However, the use of cord blood in biomedical research has been limited by access to viable samples. Here, we present a cost-effective, self-sustaining model for the procurement of fresh umbilical cord blood components for research purposes within hospital-affiliated academic institutions.

UM171-Expanded Cord Blood Transplants Support Robust T Cell Reconstitution with Low Rates of Severe Infections

Rapid T cell reconstitution following hematopoietic stem cell transplantation (HSCT) is essential for protection against infections and has been associated with lower incidence of chronic graft-versus-host disease (cGVHD), relapse, and transplant-related mortality (TRM). While cord blood (CB) transplants are associated with lower rates of cGVHD and relapse, their low stem cell content results in slower immune reconstitution and higher risk of graft failure, severe infections, and TRM. Recently, results of a phase I/II trial revealed that single UM171-expanded CB transplant allowed the use of smaller CB units without compromising engraftment (www.clinicaltrials.gov, NCT02668315). We assessed T cell reconstitution in patients who underwent transplantation with UM171-expanded CB grafts and retrospectively compared it to that of patients receiving unmanipulated CB transplants. While median T cell dose infused was at least 2 to 3 times lower than that of unmanipulated CB, numbers and phenotype of T cells at 3, 6, and 12 months post-transplant were similar between the 2 cohorts. T cell receptor sequencing analyses revealed that UM171 patients had greater T cell diversity and higher numbers of clonotypes at 12 months post-transplant. This was associated with higher counts of naive T cells and recent thymic emigrants, suggesting active thymopoiesis and correlating with the demonstration that UM171 expands common lymphoid progenitors in vitro. UM171 patients also showed rapid virus-specific T cell reactivity and significantly reduced incidence of severe infections. These results suggest that UM171 patients benefit from rapid T cell reconstitution, which likely contributes to the absence of moderate/severe cGVHD, infection-related mortality, and late TRM observed in this cohort.

Identifying Barriers to Umbilical Cord Blood Banking in Jordan: A Cross-Sectional Survey of Obstetricians

Background: The expansion of umbilical cord blood (UCB) banking necessitates a greater understanding among obstetricians in order to responsibly inform parents about UCB collection and storage. Gaps in knowledge can compromise public UCB banking efforts and result in missed opportunities and public misguidance about UCB banking. Materials and Methods: A cross-sectional survey was disseminated among obstetricians in Amman, Jordan. The questionnaire aimed to evaluate obstetricians' knowledge of and attitude toward UCB storage and applications, as well as current practice patterns. Results: Ninety-six obstetricians responded (55% response rate), most of whom were Jordanian (71%), female (83%), resident physicians (59%), and working in either private (43%) or public (42%) hospitals, with an average of 6.5 years in practice. Only 26% had personal experience in UCB collection, and 20% had received education on UCB collection. Nearly 75% said their hospitals lacked standard operating procedures, guidelines, or infectious disease screening for UCB units. Overall knowledge about UCB was moderate, and the internet was the most common information source (54%). Overall attitudes were positive, especially in desire to expand personal knowledge about UCB, integrate information into medical residency curricula, and establish a public UCB bank in Jordan. However, many believed that ethical (61%) and religious (56%) controversies surround UCB donation. Conclusion: This study identifies deficiencies in quality control and experience in UCB collection in Jordan, as well as areas of inadequate knowledge and ethical controversies among obstetricians. These issues contribute to public misinformation and limit public UCB donation programs, and requires improved medical education on this topic.

Furostanol Saponins from Trillium tschonoskii Promote the Expansion of Human Cord Blood Hematopoietic Stem and Progenitor Cells

Trillium tschonoskii is a medicinal plant known to biosynthesize steroidal saponins. A phytochemical investigation of the rhizomes of T. tschonoskii led to the isolation of nine new furostanol saponins (1-9) and 11 known analogues (10-20). Five of these new compounds were shown to have hydroxy groups at the C-5 and C-6 positions, while two possess a rare aglycone containing carbonyl groups at the C-16 and C-22 positions as well as a Δ¹⁷⁽²⁰⁾ double bond, and the others have conjugated double bonds in the E-ring or have different sugar chains at the C-3 position. All the isolates were tested for their effect on the expansion of human cord blood (CB) CD34⁺ hematopoietic stem and progenitor cells. It was found that CB CD34⁺ cells treated with compounds 6, 7, 9, 10, 14, 15, and 19 showed increased numbers of rigorously phenotype-defined hematopoietic stem cells. Notably, compounds 9, 10, 13, and 14 demonstrated an enhanced ability to increase the percentages and numbers of CB CD34⁺CD38^- cells and multipotential progenitors. The present study is the first to report that furostanol saponins from T. tschonoskii rhizomes can promote hematopoietic stem/progenitor cell (HSPC) expansion.

Impact of detectable measurable residual disease on umbilical cord blood transplantation

The impact of measurable residual disease (MRD) on cord blood transplantation (CBT) outcomes has remained debated. To address this issue, we assessed the impact of measurable MRD at CBT on outcomes in large cohort of patients with acute leukemia. Inclusion criteria included adult patients with acute myeloid (AML) or acute lymphoblastic leukemia (ALL), CBT as first allo-HCT in first or second complete remission (CR) at transplantation, and known MRD status at the time of CBT. Data from 506 patients were included in the analysis. Among them, 317 patients had AML and 189 had ALL. Positive MRD was reported in 169 (33%) patients while the remaining 337 patients were MRD negative at CBT. At 2 years, relapse incidence was 18% in patients with MRD negativity vs 33% in those with MRD positivity at transplantation (P < .001). Two-year leukemia-free survival (LFS) and overall survival (OS) were 57% and 60%, respectively, in MRD negative patients, vs 38% (P < .001) and 48% (P = .004), respectively, in those with MRD positivity. There was no interaction between the impact of MRD on OS and LFS and diagnosis (ie, ALL vs AML), single or double CBT, and reduced-intensity or myeloablative conditioning. On multivariate analysis, MRD positivity was associated with a higher risk of relapse (HR = 1.8, P = .003), comparable non-relapse mortality (P = .44), worse LFS (HR = 1.4, P = .008) and a trend towards worse OS (HR = 1.3, P = .065). In conclusion, these data suggest that novel strategies that are aiming to achieve MRD negativity at CBT are needed for leukemic patients with positive MRD pre-CBT.

A humoral solution: Autologous blood products and tissue repair

Autologous blood-derived products (ABP) are the focus of growing scientific interest and are investigated and used for multiple medical indications. ABPs hold promise thanks to their availability, ease of preparation, and low risk of adverse allogenic reaction, hypersensitivity, and contamination. Compositional analysis of ABPs reveals a diverse mixture of cellular components, cytokines and growth factors that play roles in healing processes such as tissue proliferation and angiogenesis, modulation of the local environment through chemotaxis and regulation of inflammation and the extracellular matrix, as well as several immunomodulatory actions. Thus, the administration of ABP induces supraphysiological levels of components necessary for orchestrating reparative efforts in currently difficult-to-treat medical conditions. In this article, we review the variety of autologous blood-derived products, their composition, current clinical uses, regulatory climate, and mechanisms of action.

Screening for pre-leukemia TEL-AML1 chromosomal translocation in banked cord blood units: cord blood bank perspective

Acute lymphocytic leukemia is the most common leukemia in children. Many studies suggest the existence of two subsequent hits in order for the disease to occur. TEL-AML1 (ETV6-RUNX1) is considered an initial genetic hit that occurs prenatally and generates a pre-leukemia clone. In cord blood (CB) stem cell transplantation, donor cell leukemia (DCL) is one of the complications associated with the presence of the pre-leukemic clone. The aim of this study was to identify the prevalence of ETV6-RUNX1 translocation in CB units and the feasibility in implementing such a screening test, to ensure the safety of the CB units. A total of 424 CB samples were tested from the CB units banked at KAIMRC-CBB. RNA was extracted and cDNA synthesis was performed on 1 ug input RNA using Reverse Transcriptase RT-PCR methodology. Chromosomal translocation ETV6-RUNX1 was tested using real time quantitative PCR methodology. Our study showed undetectable levels of ETV6-RUNX1 in all tested CB samples. The samples were analyzed for the chromosomal translocation ETV6-RUNX1 under controlled conditions, using control and fusion genes with known concentrations. The result of this study does not rule out the importance of this screening test in predicting and/or preventing DCL. Moreover, the outcome strengthens the adopted system in our CBB for mother medical history screening prior to donation. We propose adding this test during the verification testing stage, prior to the release of CB units selected for transplantation rather than at the banking stage.

Arterial endothelium creates a permissive niche for expansion of human cord blood hematopoietic stem and progenitor cells

Background

Although cord blood (CB) offers promise for treatment of patients with high-risk hematological malignancies and immune disorders, the limited numbers of hematopoietic stem cell (HSC)/progenitor cell in a CB unit and straitened circumstances in expanding ex vivo make it quite challenging to develop the successful cell therapies.

Methods

In this study, a novel strategy has been developed to support ex vivo expansion of hematopoietic stem and progenitor cells (HSPCs) by coculture with engineered human umbilical arterial endothelial cells (HuAECs-E4orf1-GFP), which expresses E4ORF1 stably by using a retroviral system.

Results

Coculture of CD34⁺ hCB cells with HuAECs-E4orf1-GFP resulted in generation of considerably more total nucleated cells, CD34⁺CD38⁻, and CD34⁺CD38⁻CD90⁺ HSPCs in comparison with that of cytokines alone or that of coculture with human umbilical vein endothelial cells (HuVECs) after 14-day amplification. The in vitro multilineage differentiation potential and in vivo repopulating capacity of the expanded hematopoietic cells cocultured with HuAECs-E4orf1-GFP were also markedly enhanced compared with the other two control groups. DLL4, a major determinant of arterial endothelial cell (EC) identity, was associated with CD34⁺ hCB cells amplified on HuAECs-E4orf1-GFP.

Conclusions

Collectively, we demonstrated that HuAECs acted as a permissive niche in facilitating expansion of HSPCs. Our study further implicated that the crucial factors and related pathways presented in HuAECs may give a hint to maintain self-renewal of bona fide HSCs.

Changes in Knowledge about Umbilical Cord Blood Banking and Genetic Tests among Pregnant Women from Polish Urban and Rural Areas between 2010-2012 and 2017

The aim of this study was to evaluate knowledge of umbilical cord blood (UBC) banking and prenatal genetic diagnosis among pregnant women from rural and urban areas, and how this knowledge changed within a five-year period. A survey by questionnaire was conducted between 2010 and 2012, and in 2017 in public hospitals; the study population comprised 6128 women, with 2797 patients from the years 2010-2012 and 3331 from the year 2017. 41% of the studied population declared that they were living in rural areas. In the 2010-2012 period, fewer women from rural areas knew about UBC banking. In 2017 that same relative difference in knowledge persisted, but the percentage of women who now knew about this procedure rose significantly in both studied groups. Prenatal diagnosis was more familiar for urban inhabitants both in 2010 and 2017 but as with the UBC data, a trend of growing awareness was also seen in pregnant women from rural areas. Knowledge of new techniques such as UBC banking and genetic tests has grown among pregnant women during the time frame of our study, but there is still a need to emphasize the benefits of these two possibilities to pregnant women, especially among rural inhabitants.

Discarded plasma obtained after cord blood volume reduction as an alternative for fetal calf serum in mesenchymal stromal cells cultures

BACKGROUND

Utilization of the fetal calf serum (FCS) carries a potential health risk and raises growing economic and ethical problems. Umbilical cord blood volume reduction, required for banking, provides clinical-grade umbilical cord blood plasma (UCBP) discarded as a waste. The aim of this study was to test whether serum derived from UCBP could replace FCS for the amplification of mesenchymal stromal cells (MSCs).

STUDY DESIGN AND METHODS

To this end, the amplification of the MSCs and mesenchymal progenitors was estimated in the presence of serum derived from UCBP and its cytokine content was determined by cytometric bead array and enzyme-linked immunosorbent assay techniques. As a comparison, other sources of clinical-grade human serum were tested in parallel: serum derived from solvent/detergent-treated fresh-frozen plasma (S/D-FFP) and from platelet (PLT)-rich and PLT-poor umbilical plasma.

RESULTS

Serum derived from UCBP-supplemented culture sustains identical amplification of MSCs and their progenitors as in the case of FCS addition. Furthermore, the assays reveal the presence in the serum derived from UCBP of cytokines influencing the properties of MSCs (basic fibroblast growth factor, transforming growth factor-β, vascular endothelial growth factor, and interleukin-8) or involved in the development of the myeloid lineage (thrombopoietin, erythropoietin, granulocyte-colony-stimulating factor, and granulocyte-macrophage-colony-stimulating factor). Also, our study indicates important differences between neonatal and adult-derived serum. Poor cytokine content in the S/D-FFP makes a less efficient replacement of FCS comparing to other human blood-derived supplements.

CONCLUSION

Our work shows that the discarded human cord blood plasma from volume reduction is an easily obtainable and greatly available, xeno-free source of serum that is a highly efficient replacement of FCS in sustaining MSC growth.

Short-Term exposure of umbilical cord blood CD34+ cells to human platelet lysate and cytokines enhances engraftment

BACKGROUND

Intra bone marrow (IBM) injection has been proposed as a strategy to bypass homing inefficiencies associated with intravenous (IV) hematopoietic progenitor stem cell (HSPC) transplantation and thus increases the number of HSPC that engraft. Despite physical delivery into the bone marrow cavity, many donor cells are rapidly redistributed by vascular perfusion. Thus, the objective of our study was to evaluate the ability of human platelet lysates (hPL) to improve HSPC retention into the bone marrow and consequently to improve engraftment.

STUDY DESIGN AND METHODS

HSPC were isolated from human umbilical cord blood. HSPC were seeded in the wells of a 24-well microplate and exposed to increasing concentrations of hPL with or without cytokines for 24 hours. Following priming, HSPC cells chemotaxis to rhSDF-1 was determined in vitro and engraftment in NSG mice was evaluated.

RESULTS

Priming of cord blood CD34+ cells to a combination of hPL and cytokines resulted in a significant increase (up to 3-fold) in the expression of the CD34 antigen on HSPC. This effect was closely correlated to a significantly increased (up to 7-fold) migration toward a rhSDF-1 concentration gradient. In addition, IBM injection of CD34+ cells previously primed with hPL+cytokines into NSG mice showed significantly increased engraftment as measured by human platelet numbers, human CD45 and human CD34+ cells for unprimed and primed cells, respectively.

CONCLUSION

The use of hPL + cytokines as a short-term priming treatment for UCB could be an advantageous strategy to improve clinical outcomes following IBM injection.

Red blood cell and platelet transfusion support in the first 30 and 100 days after allogeneic hematopoietic cell transplant

BACKGROUND

Allogeneic hematopoietic stem cell transplant (allo-HSCT) recipients often require substantial but variable transfusion support.

STUDY DESIGN AND METHODS

This single-center, retrospective study evaluated the red blood cell (RBC) and platelet (PLT) transfusion data of first-time allo-HSCT recipients transplanted in 2011 to 2017. Multivariate analyses were performed to assess the associations between patient and transplant-related factors and transfusion requirements.

RESULTS

The study included 1762 patients who received peripheral blood stem cells (88.2%), marrow (7.0%), or umbilical cord (4.8%) from matched related (38.3%), unrelated (49.2%), or haploidentical (7.8%) donors. Almost all patients required RBCs (88.3%) or PLTs (97.4%) during the first 30 days, with medians of 3 (range, 1-37) RBC and 6 (range, 1-144) PLT units transfused. Fewer patients required RBC (43.8%) or PLT (27.3%) transfusions during Days 31 to 100, but the median (range) numbers of RBC and PLT units remained high at 3 (1-36) and 6 (1-116) among transfused patients. RBC and PLT transfusion independence was reached in medians of 24 (95% confidence interval [CI], 22-26) and 12 (95% CI, 11-12) days, respectively. Haploidentical donor, cord graft, and requiring RBC transfusions in the 10 days before HSCT were the most significant independent factors predictive of increased transfusion requirements. Advanced disease, diagnosis, ABO incompatibility, conditioning intensity, CD34+ cell dose, presence of severe acute graft-vs-host disease, and changes in recommended transfusion triggers were also shown to independently impact transfusion requirements.

CONCLUSIONS

This study provided for the first time quantitative and comparative transfusion data on a large contemporary cohort of HSCT recipients, including haploidentical and cord graft recipients, and identified factors predictive of increased transfusions.

Estimation of Total Costs in Pediatric and Young Adult Patients with Relapsed or Refractory Acute Lymphoblastic Leukemia Receiving Tisagenlecleucel from a U.S. Hospital's Perspective

BACKGROUND

Tisagenlecleucel was approved for the treatment of pediatric and young adult patients with relapsed/refractory (r/r) B-cell acute lymphoblastic leukemia (ALL) based on the pivotal ELIANA trial.

OBJECTIVE

To comprehensively evaluate the total costs associated with tisagenlecleucel treatment, including costs from pre- to postinfusion periods of tisagenlecleucel in addition to the cost of tisagenlecleucel.

METHODS

An economic model was developed to estimate total costs associated with tisagenlecleucel treatment from the time of leukapheresis to 2 months postinfusion from a U.S. hospital's perspective. Costs were estimated based on resource use and safety management from the ELIANA trial and were considered during the pretreatment, tisagenlecleucel infusion, and follow-up periods of treatment. Cost components included leukapheresis, lymphodepleting chemotherapy, tisagenlecleucel infusion and hospital administration, inpatient and intensive care unit admissions, medical professional visits, laboratory tests and procedures, and management of major adverse events. Scenario analyses were conducted by varying key assumptions related to adverse events and hospitalization.

RESULTS

The total cost associated with tisagenlecleucel treatment among pediatric and young adult patients with r/r ALL was estimated to be $612,779, of which $137,636 (22.5%) was in addition to the list price of tisagenlecleucel ($475,000) and the associated administration cost of $143.08. The top 3 drivers of the additional cost were adverse event management ($70,968; 51.6%), inpatient and intensive care unit admissions not attributed to adverse events ($57,952; 42.1%), and laboratory tests and procedures ($5,209; 3.8%). The costs incurred during the pretreatment, infusion, and follow-up periods were $29,002, $476,659, and $107,118, respectively. In the scenario analyses, the total costs ranged from $483,169 (tisagenlecleucel treatment in the outpatient setting without adverse events) to $672,373 (tisagenlecleucel treatment in the inpatient setting with grade 3/4 cytokine release syndrome and B-cell aplasia).

CONCLUSIONS

In this economic model, tisagenlecleucel treatment among pediatric and young adult patients with r/r ALL was estimated to cost $612,779. The cost of care in addition to the price of tisagenlecleucel accounted for 22.5% of the total, with adverse event management and inpatient and intensive care unit admissions being main drivers. Further studies are warranted to assess the cost of tisagenlecleucel treatment in the context of current standards of care in real-world clinical practice.

DISCLOSURES

This study was supported by Novartis. The study sponsor was involved in several aspects of the research, including the study design, the interpretation of data, the writing of the manuscript, and the decision to submit the manuscript for publication. Hao is an employee of Novartis and has stock/stock options. Yang, Chai, Qi, and Wu are employees of Analysis Group, which received consulting fees from Novartis for work on this study. Part of the material in this manuscript was presented at the American Society of Hematology Annual Meeting held December 7-10, 2019, in Orlando, FL.

The influence of stem cell source on transplant outcomes for pediatric patients with acute myeloid leukemia

When hematopoietic stem cell transplant (HSCT) is necessary for children with acute myeloid leukemia (AML), there remains debate about the best stem cell source. Post-HSCT relapse is a common cause of mortality, and complications such as chronic graft versus host disease (cGVHD) are debilitating and life-threatening. To compare post-HSCT outcomes of different donor sources, we retrospectively analyzed consecutive transplants performed in several international centers from 2005 to 2015. A total of 317 patients were studied: 19% matched sibling donor (MSD), 23% matched unrelated donor (MUD), 39% umbilical cord blood (UCB), and 19% double UCB (dUCB) recipients. The median age at transplant was 10 years (range, 0.42-21 years), and median follow-up was 4.74 years (range, 4.02-5.39 years). Comparisons were made while controlling for patient, transplant, and disease characteristics. There were no differences in relapse, leukemia-free survival, or nonrelapse mortality. dUCB recipients had inferior survival compared with matched sibling recipients, but all other comparisons showed similar overall survival. Despite the majority of UCB transplants being HLA mismatched, the rates of cGVHD were low, especially compared with the well-matched MUD recipients (hazard ratio, 0.3; 95% confidence interval, 0.14-0.67; P = .02). The composite measure of cGVHD and leukemia-free survival (cGVHD-LFS), which represents both the quality of life and risk for mortality, was significantly better in the UCB compared with the MUD recipients (HR, 0.56; 95% confidence interval, 0.34-1; P = .03). In summary, the use of UCB is an excellent donor choice for pediatric patients with AML when a matched sibling cannot be identified.

GVHD-free, relapse-free survival provides novel clues for optimizing allogeneic-HSCT for adult T-cell leukemia/lymphoma

The outcome of allogeneic hematopoietic stem cell transplantation (allo-HSCT) for adult T-cell leukemia/lymphoma (ATL) is still unsatisfactory. To illustrate the advantages and disadvantages of each donor source, we performed a nationwide retrospective study of graft-versus-host disease (GVHD)-free, relapse-free survival (GRFS) of patients with allo-HSCT-treated ATL. One-year GRFS did not significantly differ between patients who received related bone marrow transplantation (R-BMT; 26%, n = 117), related peripheral blood stem cell transplantation (R-PBSCT; 22%, n = 225), unrelated bone marrow transplantation (UR-BMT; 26%, n = 619), and cord blood transplantation (CBT; 21%, n = 359; p = 0.09). This was attributable to a low incidence of systemically-treated chronic GVHD after CBT (9% at 1 year) and reduced non-GVHD/relapse mortality after R-PBSCT (9% at 1 year). Among patients transplanted in complete remission (CR), 1-year overall survival after CBT (52%, n = 132) was not inferior to that after R-BMT (55%, n = 51), R-PBSCT (57%, n = 79), and UR-BMT (58%, n = 280; p = 0.15), and relapse rates were equivalent among the four sources (p = 0.19). Our results suggest that all donor sources are feasible for CR patients and that GRFS provides important clues toward optimizing allo-HSCT for ATL.

A 3D engineered scaffold for hematopoietic progenitor/stem cell co-culture in vitro

Proliferation of HPSCs in vitro can promote its broad clinical therapeutic use. For in vitro co-culture, interaction between the stem cell and feeder cell as well as their spatial position are essential. To imitate the natural microenvironment, a 3D engineered scaffold for CD34⁺ cells co-culture was established via 3D bioprinting. Herein, the concentration of hydrogel and the ratio of two kinds of cells were optimized. Flow cytometry, real time PCR and RNA-seq technology were applied to analyze the effect of the engineered scaffold on expanded cells. After 10 days co-culture with the engineered scaffold, the expansion of CD34⁺CD38^- cells can reach 33.57-folds and the expansion of CD34⁺CD184⁺ cells can reach 16.66-folds. Result of PCR and RNA-seq indicates that the CD34⁺ cells in 3D group exhibited a tendency of interaction with the engineered scaffold. Compared to 2D co-culture, this customizable 3D engineered scaffold can provide an original and integrated environment for HPSCs growth. Additionally, this scaffold can be modified for different cell co-culture or cell behavior study.

Preeclampsia in pregnancy affecting the stemness and differentiation potency of haematopoietic stem cell of the umbilical cord blood

BACKGROUND

Umbilical cord blood (UCB) has been proposed as the potential source of haematopoietic stem cells (HSC) for allogeneic transplantation. However, few studies have shown that a common disease in pregnancy such as preeclampsia would affect the quality of UCB-HSC. Total nucleated cell count (TNC) is an important parameter that can be used to predict engraftment including UCB banking. Colony forming unit (CFU) assay is widely used as an indicator to predict the success of engraftment, since direct quantitative assay for HSC proliferation is unavailable. The aim of this study is to investigate the effects of preeclampsia in pregnancy on the stemness and differentiation potency of UCB-HSC.

METHODS

Mononuclear cells (MNC) were isolated from UCB and further enriched for CD34+ cells using immune-magnetic method followed by CFU assay. A panel of HSC markers including differentiated haematopoietic markers were used to confirm the differentiation ability of UCB-HSC by flow cytometry analysis.

RESULTS/ DISCUSSION

The HSC progenitor's colonies from the preeclampsia group were significantly lower compared to the control. This correlates with the low UCB volume, TNC and CD34+ cells count. In addition, the UCB-enriched CD34+ population were lymphoid progenitors and capable to differentiate into natural killer cells and T-lymphocytes.

CONCLUSION

These findings should be taken into consideration when selecting UCB from preeclamptic mothers for banking and predicting successful treatment related to UCB transplant.

Enhanced collection of phenotypic and engrafting human cord blood hematopoietic stem cells at 4°C

The number of hematopoietic stem cells (HSCs) collected in cord blood (CB) at the birth of a baby is a limiting factor for efficacious use of CB in hematopoietic cell transplantation (HCT). We now demonstrate that collecting and processing of human CB at 4°C within minutes of the baby's birth results in significantly enhanced numbers of rigorously defined phenotypic HSC and self-renewing NSG immune-deficient mouse engrafting and SCID-repopulating cells. This was associated with decreased numbers of hematopoietic progenitor cells (HPC), as noted previously for hypoxia collected/processed cells blocking ambient air induced differentiation of HSC to HPC. We have thus defined a simple, cost-effective, means to collect increased numbers of CB HSC, of potential use for clinical CB HCT.

Perinatal tissues and cells in tissue engineering and regenerative medicine

Perinatal tissues are an abundant source of human extracellular matrix proteins, growth factors and stem cells with proved potential use in a wide range of therapeutic applications. Due to their placental origin, these tissues possess unique biological properties, including being angiogenic, anti-inflammatory, anti-fibrotic, anti-microbial and immune privileged. Additionally, as a temporary organ, placenta is usually discarded as a medical waste, thus providing an easily available, cost effective, 'unlimited' and ethical source of raw materials. Although some of these tissues, such as the amniotic membrane and umbilical cord, have been used in clinical practices, most of them continue to be highly under explored. This review aims to outline the most relevant applications of perinatal tissues as a source of biomaterials and stem cells in the exciting fields of tissue engineering and regenerative medicine (TERM), as well as highlight how these solutions can be used to overcome the shortage of adequate scaffolds and cell sources that currently hampers the translation of TERM strategies towards clinical settings. STATEMENT OF SIGNIFICANCE: Stem cells and extracellular matrix derived from perinatal tissues such as placenta and umbilical cord, have drawn great attention for use in a wide variety of applications in the biomedical field. Due to their origin, these tissues possess unique biological properties, including being angiogenic, anti-inflammatory, anti-fibrotic, anti-microbial and immune privileged. Also they are typically considered medical waste, thus providing an easily available, cost effective, 'unlimited' and ethical source of raw materials. This work aims to present and discuss the most relevant applications of perinatal tissues as a source of biomaterials and stem cells in the exciting fields of tissue engineering and regenerative medicine (TERM).

Cord blood transplantation for acute leukemia

INTRODUCTION

Umbilical cord blood transplantation (UCBT) is a suitable alternative for patients with acute leukemia (AL) in need of an allograft and who lack an HLA-matched donor. Single-institution and registry studies have shown that, in both children and adults with AL, the outcome of UCBT is comparable to that of matched unrelated donor. At the same time, these studies have highlighted some limitations of UCBT, such as increased early mortality and delayed recovery of both hematopoietic and immune compartment, which hamper a more widespread adoption of this approach.

AREAS COVERED

In this review, we will analyze the current results of UCBT in children and adults with AL, including comparisons with other hematopoietic stem cell sources and transplant strategies. We will also discuss important factors to be considered when selecting UCB units, as well as future strategies to further improve the outcome of UCBT recipients.

EXPERT OPINION

The utilization of UCBT for the treatment of AL patients has decreased in recent years. However, recent clinical data suggesting that UCBT might offer better results in patients with minimal residual disease, as well as innovative strategies to facilitate engraftment, reduce transplant-related mortality, and optimize anti-leukemic activity, may pave the way toward a second youth for use of UCB cells.

Factors Associated With Umbilical Cord Blood Collection Quality in Japan

Background

Umbilical cord blood (UCB) has become an established alternative source of hematopoietic stem cells with marrow and postmobilization peripheral blood. The presence of a large amount of clots may lead to the deterioration of cord blood quality. To improve UCB quality as a source of hematopoietic stem cells in Japan, we examined factors associated with UCB collection methods from the viewpoint of eliminating the presence of clots.

Methods

In August 2019, we requested the directors of 74 certified facilities to provide information on UCB collection methods in Japan. A total of 46 (62.2%) of them responded with valid information on a total of 2,892 UCB collections. In this study, collected UCB without clots macroscopically was evaluated as a high-quality UCB.

Results

The 2,891 UCB collections described during the study period were divided to those with (n = 760, 26.3%) and without clots (high quality; n = 2,131, 73.7%). Multivariate analysis revealed single puncture as a factor determining high-quality UCB collection (adjusted odds ratio (ORs): 1.80, 95% confidence interval (CI): 1.3 - 5.4, P = 0.01).

Conclusions

Single puncture is an independent effective factor determining high-quality manual UCB collection in Japan.

Regenerative and protective effects of dMSC-sEVs on high-glucose-induced senescent fibroblasts by suppressing RAGE pathway and activating Smad pathway

Background

Fibroblasts are crucial for supporting normal wound healing. However, the functional state of these cells is impaired in diabetics because of a high-glucose (HG) microenvironment. Small extracellular vesicles (sEVs) have emerged as a promising tool for skin wound treatment. The aim of this study was to investigate the effects of sEVs derived from human decidua-derived mesenchymal stem cells (dMSC-sEVs) on HG-induced human dermal fibroblast (HDF) senescence and diabetic wound healing and explore the underlying mechanism.

Methods

We first created a HDF senescent model induced by HG in vitro. dMSC-conditioned medium (dMSC-CM) and dMSC-sEVs were collected and applied to treat the HG-induced HDFs. We then examined the proliferation, migration, differentiation, and senescence of these fibroblasts. At the same time, the expressions of RAGE, p21 RAS, Smad2/3, and pSmad2/3 were also analyzed. Furthermore, pSmad2/3 inhibitor (SB431542) was used to block the expression of pSmad2/3 to determine whether dMSC-sEVs improved HDF senescence by activating Smad pathway. Finally, we assessed the effect of dMSC-sEVs on diabetic wound healing.

Results

The HG microenvironment impaired the proliferation, migration, and differentiation abilities of the HDFs and accelerated their senescence. dMSC-CM containing sEVs improved the proliferation and migration abilities of the HG-induced fibroblasts. dMSC-sEVs internalized by HG-induced HDFs not only significantly promoted HDF proliferation, migration, and differentiation, but also improved the senescent state. Furthermore, dMSC-sEVs inhibited the expression of RAGE and stimulated the activation of Smad signaling pathway in these cells. However, SB431542 (pSmad2/3 inhibitor) could partially alleviate the anti-senescent effects of dMSC-sEVs on HG-induced HDFs. Moreover, the local application of dMSC-sEVs accelerated collagen deposition and led to enhanced wound healing in diabetic mice. The detection of PCNA, CXCR4, α-SMA, and p21 showed that dMSC-sEVs could enhance HDF proliferation, migration, and differentiation abilities and improve HDF senescent state in vivo.

Conclusion

dMSC-sEVs have regenerative and protective effects on HG-induced senescent fibroblasts by suppressing RAGE pathway and activating Smad pathway, thereby accelerating diabetic wound healing. This indicates that dMSC-sEVs may be a promising candidate for diabetic wound treatment.

NEW HORIZONS ON STEM CELL CRYOPRESERVATION THROUGH THE ARTIFICIAL EYES OF CD 34+, USING MODERN FLOW CYTOMETRY TOOLS

Hematopoietic stem cell (HSC) cryopreservation is a critical step in autologous and cord blood transplantation (CBT). In most circumstances, cryopreservation is performed in a mixture containing dimethyl sulfoxide (DMSO), since DMSO is necessary to secure cell viability. Most centers use a controlled rate (slow) freezing before the long-term storage at vapor phase liquid nitrogen (LN₂) temperatures (≤ -160 °C). The primary objectives for laboratories supporting HSCT programs are to provide secure storage for leukapheresis and cord blood products, and to adequately characterize the functional properties of the grafts before their infusion. In the autologous setting, the large majority of the published results dealt with the assessment of the graft before cryopreservation. On the contrary, in CBT, before a CB unit is released, a sample obtained from a contiguous segment of that CB unit needs to be tested to verify HLA type and cell viability. The effects of graft handling, cryopreservation, storage and thawing on the recovery of CD34+ cells needs to be carefully analyzed and standardized on a global level. Some technical unresolved issues still limit the application of the ISHAGE derived single platform flow cytometry protocol for the assessment of the thawed material; based on these considerations, an adaptation of both the acquisition setting and the gating strategyis necessary for reliable measurement of CD34-expressing HSC in cryopreserved grafts. Artificial intelligence applied to "big data" may provide a new tool for improving advanced processing procedures and quality management guidelines in this area of investigation.

Extracellular vesicles from human umbilical cord blood plasma modulate interleukin-2 signaling of T cells to ameliorate experimental autoimmune encephalomyelitis

Human umbilical cord blood (UCB) cell-derived extracellular vesicles (EV) reportedly play immunosuppressive roles; however, UCB plasma-derived extracellular vesicles (CBP EVs) remain poorly studied. We examined the immunosuppressive potential of CBP EVs compared to that of adult blood plasma-derived extracellular vesicles (ABP EVs) in vitro and constructed an experimental autoimmune encephalomyelitis (EAE) model. Methods: CBP EVs were isolated by ultracentrifugation and their proteomic profiling was performed using the high-resolution liquid chromatography with tandem mass spectrometry. Human T lymphocytes or mouse splenocytes labeled with carboxyfluorescein succinimidyl ester were incubated with CBP EV to measure the immunosuppressive function of CBP EV. The effect on T-cell polarization was analyzed by flow cytometry and enzyme-linked immunospot assay. The matrix metalloproteinase (MMP) function in CBP EV was specifically inhibited using a chemical inhibitor. The efficacy of CBP EVs in the EAE mouse model was determined by scoring the symptoms and analyzing cell phenotype and cytokines using mouse splenocytes. We generated genetically engineered artificial EVs using HLA/MIC-null HEK293T (H1ME-5) cell line to characterize the immunosuppressive effect of CBP EV. Results: CBP EVs primarily inhibited the proliferation of T cells by reducing the production of IL-2. Specifically, CBP EV-derived matrix metallopeptidase cleaved the IL-2 receptor α (CD25) on the surface of activated T cells, consequently downregulating IL-2 signaling in response to IL-2R engagement. Although the inhibition of MMP activity in CBP EVs abrogated CD25 cleavage and restored IL-2 production in activated T cells, the immunosuppressive response was not fully recovered. Thus, we further analyzed changes in immunosuppressive cells such as regulatory T cells and bone marrow-derived suppressor cells by CBP EV. Further, GAL-3, GAL-7, S100-A7, MMP-9, MMP-8, HSP-72, and PIP were highly enriched in CBP EV-mimics in which they served as pivotal mediators of CBP EV-induced immunosuppressive effects. Therefore, we generated genetically engineered GAL-3, GAL-7, S100-A7, MMP-9, MMP-8, HSP-72, and PIP-EVs using HLA/MIC-null HEK293T cells to characterize the immunosuppressive effect of these molecules. Among these, MMP-9 and HSP-72-enriched EVs showed the most significant T cell immunosuppression. Conclusion: CBP EVs inhibited T cell proliferation and EAE development by modulating IL-2 signaling and immunosuppressive cell fate. CBP EVs contain critical components for immunosuppression and that CBP EV mimics, specifically those expressing MMP-9 and HSP-72, may offer a novel promising strategy for the treatment of various autoimmune diseases.

Use of Autologous Cord Blood Mononuclear Cells Infusion for the Prevention of Bronchopulmonary Dysplasia in Extremely Preterm Neonates: A Study Protocol for a Placebo-Controlled Randomized Multicenter Trial [NCT03053076]

Background: Despite the rapid advance of neonatal care, bronchopulmonary dysplasia (BPD) remains a significant burden for the preterm population, and there is a lack of effective intervention. Stem cell depletion because of preterm birth is regarded as one of the underlying pathological mechanisms for the arrest of alveolar and vascular development. Preclinical and small-sample clinical studies have proven the efficacy and safety of stem cells in treating and preventing lung injury. However, there are currently no randomized clinical trials (RCTs) investigating the use of autologous cord blood mononuclear cells (ACBMNC) for the prevention of BPD in premature infants. The purpose of this study is to investigate the effects of infusion of ACBMNC for the prevention of BPD in preterm neonates <28 weeks. Methods: In this prospective, randomized controlled double-blind multi-center clinical trial, 200 preterm neonates <28 weeks gestation will be randomly assigned to receive intravenous ACBMNC infusion (5 × 107 cells/kg) or placebo (normal saline) within 24 h after birth in a 1:1 ratio using a central randomization system. The primary outcome will be survival without BPD at 36 weeks of postmenstrual age or at discharge, whichever comes first. The secondary outcomes will include the mortality rate, other common preterm complication rates, respiratory support duration, length, and cost of hospitalization, and long-term outcomes after a 2-year follow-up. Conclusion: This will be the first randomized, controlled, blinded trial to evaluate the efficacy of ACBMNC infusion as a prevention therapy for BPD. The results of this trial will provide valuable clinical evidence for recommendations on the management of BPD in extremely preterm infants. Clinical Trial Registration: ClinicalTrials.gov, NCT03053076, registered 02/14/2017, retrospectively registered, https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S0006WN4&selectaction=Edit&uid=U0002PLA&ts=2&cx=9y23d4 (Additional File 2).

Improvement of early mortality in single-unit cord blood transplantation for Japanese adults from 1998 to 2017

The major limitation of cord blood transplantation (CBT) for adults remains the delayed hematopoietic recovery and higher incidence of graft failure, which result in a higher risk of early mortality in CBT. We evaluated early overall survival (OS), non-relapse mortality (NRM), neutrophil engraftment, acute graft-vs-host disease, and cause of early death among 9678 adult patients who received single-unit CBT in Japan between 1998 and 2017. The probability of OS at 100 days was 64.4%, 71.7%, and 78.9% for the periods 1998 to 2007, 2008 to 2012, and 2013 to 2017, respectively (P < .001). The cumulative incidences of NRM at 100 days during the same period were 28.3%, 20.8%, and 14.6%, respectively (P < .001). The cumulative incidences of neutrophil engraftment were also improved during the same period (P < .001). The most common cause of death within 100 days after CBT was bacterial infection in 1998 to 2007 and primary disease in the latter two time periods. Across the three time periods, the proportions of deaths from bacterial and fungal infection, graft failure, hemorrhage, sinusoidal obstructive syndrome, and organ failure decreased in a stepwise fashion. Landmark analysis of OS and NRM after 100 days showed that OS did not change over time in the multivariate analysis. Our registry-based data demonstrated a significant improvement of early OS after CBT for adults over the past 20 years. The landmark analysis suggested that improvement of early mortality could lead to an improvement of long-term OS after CBT.

Prospective evaluation of alternative donor from unrelated donor and cord blood in adult acute leukemia and myelodysplastic syndrome

A prospectively registered observational study was conducted to assess the significance of allogeneic hematopoietic stem cell transplantation from highly HLA-matched unrelated donors (UD) and cord blood (CB) on outcomes in adult acute leukemia (AL) and myelodysplastic syndrome (MDS). Between 2007 and 2015, 231 transplant-eligible patients were registered for a phase 2 study of alternative donor transplantation. After registration, a sufficient time period was given to find appropriate UD. Patients received CB transplantation (CBT) if an appropriate UD was unavailable. In total, 119 patients received CBT (106 AL and 13 MDS) and 91 patients received UD transplantation (UDT) (86 AL and 5 MDS). The median age was 39 years in both groups. The primary objective was overall survival (OS); secondary objectives included cumulative incidences of non-relapse mortality (NRM) and relapse, and disease-free survival. Diagnosis, disease status at transplantation, refined disease risk index, and hematopoietic cell transplant-specific comorbidity index did not differ between UDT and CBT. In multivariate analyses, graft source was not a significant risk factor for all objectives. In adjusted analyses, UDT and CBT showed similar OS, NRM, and relapse in this prospective study. CB can be a comparable alternative stem cell source to UD by achieving a timely transplant.

Effect of graft-versus-host disease on outcomes after pediatric single cord blood transplantation

The effect of GVHD on transplant outcomes after unrelated cord blood transplantation (UCBT) is not yet fully understood. Pediatric patients aged 0-15 years with acute leukemia or myelodysplastic syndrome who underwent their first UCBT (n = 740) were selected from the Japanese registry. Fifty percent of the patients received a UCB unit containing more than 5.0 × 10⁷/kg total nucleated cells. The occurrence of grade III-IV acute GVHD was associated with a higher risk of non-relapse mortality (NRM, hazard ratio [HR] 4.07, P < 0.001) compared with no acute GVHD. Grade I-II acute GVHD was not associated with NRM. The occurrence of grade I-II or grade III-IV acute GVHD was not associated with a relapse risk. These findings showed that grade I-II acute GVHD carried no survival benefit and grade III-IV acute GVHD had an adverse effect (HR 1.68, P = 0.007). The occurrence of limited chronic GVHD was associated with a low risk of overall mortality (HR 0.60, P = 0.045). Severe acute GVHD should be prevented because of its association with high overall mortality and NRM in pediatric single UCBT. Mild acute GVHD provides no overall benefit. Mild chronic GVHD may be beneficial for survival.

Protective Effects of Cytomegalovirus DNA Copies ≧1000/mL for AML Patients in Complete Remission After Single Cord Blood Transplantation

Introduction

Current consensus recommends a protective effect of cytomegalovirus (CMV) infection on relapse after peripheral blood or bone marrow hematopoietic stem cell transplantation. However, in cord blood transplantation (CBT), studies of CMV infection, especially CMV viral load, on relapse are limited.

Patients and Methods

Wct e retrospectively analyzed the effect of CMV infection on 3-year outcomes in 249 AML patients according to CMV DNA load (DNA copies <1000/mL and DNA copies ≧1000/mL) within 100 days after CBT. Furthermore, eight-colour flow cytometry was used to detect peripheral blood lymphocyte subsets in 38 patients who received CBT in the last year, and 10 healthy volunteers were included as controls.

Results

The results showed that CMV DNA load did not affect the cumulative incidence of relapse in the whole study population. However, in patients with complete remission status before transplantation, the high CMV DNA load group showed a significantly reduction of relapse than the low CMV DNA load group (3.9% vs 14.6%, p=0.012, respectively), which was confirmed by multivariate analysis (HR 0.23; 95% CI, 0.07–0.73, p = 0.012). Surprisingly, high or low CMV DNA load did not significantly affect non-relapse mortality or overall survival (18.0% vs 17.0%, p=0.777 and 79.0% vs 74.6%, p=0.781, respectively). Besides, the absolute number of CD8⁺ T cells were increased in the high CMV DNA load group compared with the low DNA load group 1 month after CBT (0.20×10⁹/L vs 0.10×10⁹/L, p=0.021, respectively).

Conclusion

DNA copies ≧1000/mL for AML patients in complete remission was associated with a lower incidence of relapse after CBT, which might partly result from the expansion of CMV-related CD8⁺ T cells.

Matched-Pair Analysis of Transplant from Haploidentical, Unmanipulated Bone Marrow Donor versus HLA Identical Sibling for Patients with Hematologic Malignancies

A matched-pair analysis of transplant-related outcomes was carried out in 116 of 255 consecutive patients who received transplants from an HLA identical sibling (n = 58) or haploidentical related donor (n = 58). The 2 patient series were matched with 9 variables: period of transplant, patient and donor age, sex, diagnosis, disease phase, conditioning regimen, donor-recipient sex, and cytomegalovirus (CMV) status combinations. As graft-versus-host disease (GVHD) prophylaxis, all patients received the standard cyclosporine and methotrexate association with the addition of anti-thymocyte globulins, mycophenolate mofetil, and basiliximab in haploidentical, unmanipulated bone marrow recipients. Anti-infectious management, transfusion policy, and supportive care were identical for all patients. By comparing the 2 patient series, no statistically significant difference was observed for the cumulative incidence of advanced acute and extensive chronic GVHD, transplant-related mortality, and relapse. With a median follow-up of 3.5 years, the 5-year disease-free survival was 37% ± 6% and 36% ± 6% for HLA identical sibling and haploidentical recipients, respectively. The results of transplant from HLA identical siblings and haploidentical donors are comparable. Regardless of the HLA matching, other factors known to affect the transplant outcomes, such as donor-recipient age, sex, and CMV status combinations, might drive the search for the best donor.

ACOG Committee Opinion No. 771: Umbilical Cord Blood Banking

Since the first successful umbilical cord blood transplant in 1988, it has been estimated that more than 35,000 transplants have been performed in children and adults for the correction of inborn errors of metabolism, hematopoietic malignancies, and genetic disorders of the blood and immune system. Two types of banks have emerged for the collection and storage of umbilical cord blood: 1) public banks and 2) private banks. The benefits and limitations of public versus private umbilical cord blood banking should be reviewed with the patient because they serve different purposes. This patient discussion also should include the concept of autologous and allogeneic use of umbilical cord blood. Umbilical cord blood collected from a neonate cannot be used to treat a genetic disease or malignancy in that same individual (autologous transplant) because stored cord blood contains the same genetic variant or premalignant cells that led to the condition being treated. There is no current evidence to support the use of an autologous umbilical cord blood sample in regenerative medicine. Patients should be made aware of the quality control and regulatory organizations that provide oversight for the process of umbilical cord collection and storage. Umbilical cord blood collection should not compromise obstetric or neonatal care or alter routine practice of delayed umbilical cord clamping with the rare exception of medical indications for directed donation. Therefore, it is important to inform patients that the medical condition of the woman or neonate may prevent adequate umbilical cord blood collection. This document is updated with a statement that the routine use of private cord blood banking is not supported by available evidence and that public banking is the recommended method of obtaining cord blood. In addition, the importance of contribution from all ethnicities and races to public banks is highlighted.

Incidence and Risk Factors for Acute and Chronic Kidney Injury after Adult Cord Blood Transplantation

Although cord blood transplantation (CBT) extends allograft access, patient comorbidities, chemoradiation, and nephrotoxic medications all contribute to acute kidney injury (AKI) risk. We analyzed AKI in adult myeloablative CBT recipients who underwent transplantation from 2006 to 2017 for hematologic malignancies using cyclosporine A (CSA)/mycophenolate mofetil immunosuppression. Maximum grades of AKI were calculated using Kidney Disease: Improving Global Outcomes (grade 1, 1.5 to <2-fold; grade 2, 2 to <3-fold; or grade 3, ≥3-fold over baseline) definitions. In total, 153 patients (median 51 years [range, 23-65], 114/153 [75%] acute leukemia, 27/153 [18%] African, 88/153 [58%] cytomegalovirus seropositive, median age-adjusted hematopoietic cell comorbidity index 3 [range, 0-9], median pretransplant albumin 4.0 g/dL [range, 2.6-5.2]) underwent transplantation. The day 100 cumulative incidence of grade 1-3 AKI was 83% (95% confidence interval [CI], 77%-89%) (predominantly grade 2, median onset 40 days, range 0 to 96), and grade 2-3 AKI incidence was 54% (95% CI, 46%-62%) (median onset 43 days, range 0 to 96). Mean CSA level preceding AKI onset was high (360 ng/mL, target range 300-350). In multivariate analysis, African ancestry, addition of haploidentical CD34⁺ cells, low day -7 albumin, critical illness/intensive care admission, and nephrotoxic drug exposure (predominantly CSA and/or foscarnet) were associated with AKI. In a day 100 landmark analysis, 6% of patients with no prior AKI had chronic kidney disease (CKD) at 2 years versus 43% with prior grade 1 and 38% with prior grade 2-3 AKI (overall P= .02). Adult CBT recipients are at significant AKI risk, and AKI is associated with increased risk of CKD. Prevention strategies, early recognition, and prompt intervention are critical to mitigate kidney injury.

Cord Blood Banking and Transplantation in a National Program: Thirteen Years of Experience

BACKGROUND

The umbilical cord blood bank at the Mexican Institute of Social Security (IMSS-CBB) was established in January 2005. This lead to the development of the UCB transplantation program. Herein, we describe the experience generated during these 13 years.

STUDY DESIGN AND METHODS

Donor selection, as well as UCB collection, processing, and banking were performed under good manufacturing practices and standard operating procedures. UCB units were thawed, processed, and released for transplantation based on HLA and nucleated cell content.

RESULTS

From January 2005-December 2017, 1,298 UCB units were banked; 164 of them were released for transplantation, and 118 UCB transplants were performed. Ninety-four transplants were performed in pediatric patients and 24 in adults. Sixty percent of them corresponded to patients with leukemia, 19% were patients with marrow failure, and the rest had immunodeficiency, hemoglobinopathy, metabolic disorders, or solid tumors. Engraftment was observed in 67 patients (57% of transplanted patients) and 64% of them were still alive when writing this article. In contrast, only 13 of the 51 (25%) non-engrafting patients were alive. At the time of writing this article, the disease-free survival rate was 37%, and the overall survival rate was 47%, with survival periods of 161-3,721 days.

CONCLUSION

The IMSS UCB banking and transplantation program has had a significant impact for many IMSS patients. The hematopoietic transplantation program at our institution has benefited from the use of UCB as a source of transplantable cells.

Regimen-dependent synergism and antagonism of treprostinil and vildagliptin in hematopoietic cell transplantation

The cell dose in umbilical cord blood units is a major determinant for the outcome of hematopoietic cell transplantation. Prostaglandin analogs and dipeptidylpeptidase-4 (DPP4/CD26)-inhibitors enhance the ability of hematopoietic stem cells (HSCs) to reconstitute hematopoiesis. Here we explored the synergism between treprostinil, a stable prostaglandin agonist, and the DPP4/CD26-inhibitor vildagliptin. The combination of treprostinil and forskolin caused a modest but statistically significant increase in the surface levels of DPP4/CD26 on hematopoietic stem and progenitor cells (HSPCs) derived from murine bone and human cord blood. Their migration towards stromal cell-derived factor-1 (SDF-1/CXCL12) was enhanced, if they were pretreated with treprostinil and forskolin, and further augmented by vildagliptin. Administration of vildagliptin rescued 25% of lethally irradiated recipient mice injected with a limiting number of untreated HSPCs, but 90 to 100% of recipients injected with HSPCs preincubated with treprostinil and forskolin. The efficacy of vildagliptin surpassed that of treprostinil (60% rescue). Surprisingly, concomitant administration of vildagliptin and treprostinil resulted in poor survival of recipients indicating mutual antagonism, which was recapitulated when homing of and colony formation by HSPCs were assessed. These observations of regimen-dependent synergism and antagonism of treprostinil and vildagliptin are of translational relevance for the design of clinical trials. KEY MESSAGES: Pretreatment with treprostinil increases surface levels of DPP4/CD26 in HSPCs. Vildagliptin enhances in vitro migration of pretreated HSPCs. Vildagliptin enhances in vivo homing and engraftment of pretreated HSPCs. Unexpected mutual antagonism in vivo by concomitant administration of vildagliptin and treprostinil.

Factors Affecting Human Umbilical Cord Blood Quality Before Cryopreservation: The Importance of Birth Weight and Gestational Age

Background: Umbilical cord blood (UCB) is a rich source of hematopoietic stem cells and is useful for the treatment of blood diseases. The cost of UCB storage is high; thus, it is necessary to evaluate the quality of UCB before collection and cryopreservation. Aim: This study aimed to determine the maternal and neonatal factors that influence UCB before selection for cryopreservation. Materials and Methods: The analysis included 403 processed UCB units. The effects of maternal characteristics including maternal age and delivery method and neonatal factors such as birth weight, gestation duration, and sex on UCB quality were determined based on the collected blood volume, total nucleated cell (TNC) count, and CD34⁺ cell count. Results: The neonatal birth weight influenced the collected blood volume, TNC count, and CD34⁺ cell count. Neonates with higher birth weights produced better quality UCB units because of increased collected blood volumes, TNC counts, and CD34⁺ cell counts. However, an increase in the gestational age from 35 to 41 weeks led to decreases in the collected blood volume and CD34⁺ cell count. Conclusion: These data may be useful for determining the optimal cord blood units for collection and cryopreservation and for advising pregnant women using private banking services.

Cord blood transplantation for bone marrow failure syndromes: state of art

Hematopoietic stem cell transplantation (HSCT) and immunosuppressive therapy (IST) represent the milestones of the treatment algorithm for idiopathic and inherited bone marrow failure (BMF) disorders. However, patients lacking a suitable donor or failing IST still have a poor prognosis. Cord blood transplantation (CBT) has extended the possibility of HSCT for many patients in case of the absence of an eligible donor, and although in the last years, this procedure is less used in several hematological diseases, it remains an option for the treatment of patients with BMF syndromes. Nevertheless, optimization of conditioning regimen and cord blood unit selection is warranted to reduce the risk of graft failure and transplant-related mortality. This review summarizes the state of art of CBT in the field of BMF diseases, focusing on historical and recent issues in idiopathic aplastic anemia and inherited disorders.

MLLT3 governs human haematopoietic stem-cell self-renewal and engraftment

Limited knowledge of the mechanisms that govern the self-renewal of human haematopoietic stem cells (HSCs), and why this fails in culture, have impeded the expansion of HSCs for transplantation¹. Here we identify MLLT3 (also known as AF9) as a crucial regulator of HSCs that is highly enriched in human fetal, neonatal and adult HSCs, but downregulated in culture. Depletion of MLLT3 prevented the maintenance of transplantable human haematopoietic stem or progenitor cells (HSPCs) in culture, whereas stabilizing MLLT3 expression in culture enabled more than 12-fold expansion of transplantable HSCs that provided balanced multilineage reconstitution in primary and secondary mouse recipients. Similar to endogenous MLLT3, overexpressed MLLT3 localized to active promoters in HSPCs, sustained levels of H3K79me2 and protected the HSC transcriptional program in culture. MLLT3 thus acts as HSC maintenance factor that links histone reader and modifying activities to modulate HSC gene expression, and may provide a promising approach to expand HSCs for transplantation.

Expansion of Haematopoietic Stem and Progenitor Cells: Paving the Way for Next-Generation Haematopoietic Stem Cell Transplantation

Haematopoietic stem cell transplantation (HSCT) is now an established practice with over 70,000 transplants performed annually, and over 1.5 million around the world so far. The practice of HSCT has improved over the years due to advances in conditioning regiments, preparatory practices for patients leading up to the transplant, graft versus host disease (GVHD) and infection prophylaxis, as well as a better selection of patients. However, in many instances, the stem cells supplied to the patient may not be adequate for optimal transplantation outcomes. This may be seen in a few areas including umbilical cord blood transplantation, inadequate bone marrow, peripheral blood stem cell harvest, or gene therapy. Growing and expanding HSCs in culture would provide an increase in cell numbers prior to stem cell infusion and accelerate haematopoietic recovery, resulting in improved outcomes. Several new technologies have emerged in recent years, which have facilitated the expansion of haematopoietic stem and progenitor cells (HSPCs) in culture with good outcomes in vitro, in vivo, and in clinical trials. In this review, we will outline some of the reasons for the expansion of HSPCs as well as the new technologies facilitating the advances in HSCT.

Apelin+ Endothelial Niche Cells Control Hematopoiesis and Mediate Vascular Regeneration after Myeloablative Injury

Radiotherapy and chemotherapy disrupt bone vasculature, but the underlying causes and mechanisms enabling vessel regeneration after bone marrow (BM) transplantation remain poorly understood. Here, we show that loss of hematopoietic cells per se, in response to irradiation and other treatments, triggers vessel dilation, permeability, and endothelial cell (EC) proliferation. We further identify a small subpopulation of Apelin-expressing (Apln⁺) ECs, representing 0.003% of BM cells, that is critical for physiological homeostasis and transplant-induced BM regeneration. Genetic ablation of Apln⁺ ECs or Apln-CreER-mediated deletion of Kitl and Vegfr2 disrupt hematopoietic stem cell (HSC) maintenance and contributions to regeneration. Consistently, the fraction of Apln⁺ ECs increases substantially after irradiation and promotes normalization of the bone vasculature in response to VEGF-A, which is provided by transplanted hematopoietic stem and progenitor cells (HSPCs). Together, these findings reveal critical functional roles for HSPCs in maintaining vascular integrity and for Apln⁺ ECs in hematopoiesis, suggesting potential targets for improving BM transplantation.

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Loss of hematopoietic cells phenocopies irradiation-induced vascular defects

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Identification and characterization of Apln⁺ ECs in adult BM

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Apln⁺ ECs regulate HSC maintenance and steady-state hematopoiesis

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Apln⁺ ECs expand, respond to HSPCs, and drive post-transplantation recovery

Unlicensed Umbilical Cord Blood Units Provide a Safe and Effective Graft Source for a Diverse Population: A Study of 2456 Umbilical Cord Blood Recipients

Umbilical cord blood (UCB) transplantation (UCBT) is a curative procedure for patients with hematologic malignancies and genetic disorders and expands access to transplantation for non-Caucasian patients unable to find a fully matched unrelated donor. In 2011, the US Food and Drug Administration required that unrelated UCBT be performed using either licensed UCB or unlicensed UCB under the Investigational New Drug (IND) program. The National Marrow Donor Program manages an IND under which 2456 patients (1499 adults and 957 children, 564 with malignant diseases and 393 with nonmalignant diseases) underwent single or double UCBT between October 2011 and December 2016. The median patient age was 31 years (range, <1 to 81 years), and 50% of children and 36% of adults were non-Caucasian. The median time to neutrophil engraftment (ie, absolute neutrophil count ≥500/mm³) was 22 days for adults, 20 days for pediatric patients with malignant diseases, and 19 days for pediatric patients with nonmalignant diseases, with corresponding rates of engraftment at 42 days of 89%, 88%, and 90%. In these 3 groups of patients, the incidence of acute graft-versus-host disease (GVHD) grade II-IV was 35%, 32%, and 24%; the incidence of chronic GVHD was 24%, 26%, and 24%; and 1-year overall survival (OS) was 57%, 71%, and 79%, respectively. In multivariate analysis, younger age, lower Hematopoietic Cell Transplantation-Specific Comorbidity Index, early-stage chemotherapy-sensitive disease, and higher performance score were predictive of improved OS for adults. In a subset analysis of children with malignancies undergoing single UCBT, the use of either licensed UCB (n = 48) or unlicensed UCB (n = 382) was associated with similar engraftment and survival. The use of unlicensed UCB units is safe and effective and provides an important graft source for a diverse population.