Hematopoietic reconstitution in a patient with Fanconi's anemia by means of umbilical-cord blood from an HLA-identical sibling

The fulfilled promise and unmet potential of umbilical cord blood

PURPOSE OF REVIEW

Here, we review classic and emerging uses of umbilical cord blood and highlight strategies to improve its utility, focusing on selection of the appropriate units and cell types for the intended applications.

RECENT LITERATURE

Recent studies have shown advancements in cord blood cell utility in a variety of cellular therapies and have made strides in elucidating manners to select the best units for therapy and target new ways to improve the various cell subpopulations for their respective applications.

SUMMARY

Umbilical cord blood is a proven source of cells for hematopoietic cell transplantation and research and is an important potential source for additional cellular therapies. However, cord blood utility is limited by low "doses" of potent cells that can be obtained from individual units, a limitation that is specific to cord blood as a donor source. In addition to traditional CD34 + progenitor cells, cord blood lymphocytes are being pursued as therapeutic entities with their own unique properties and characteristics. Thus, selection of ideal units depends on the intended therapeutic entity and target, and identification of differential potency parameters is critical to drive effective banking strategies accommodating successful clinical use of cord blood in broader cell therapy settings.

Criteria for storage of cord blood units at Japan's largest cord blood bank

BACKGROUND AND OBJECTIVES

In Japan, cord blood transplantations exceed those done with adult-sourced unrelated stem cells. This study analyses cord blood (CB) storage criteria to maintain high-quality CB units.

MATERIALS AND METHODS

The Kanto-Koshinetsu Cord Blood Bank received 29,795 units from 2014 to 2021, mostly >60 mL, and 5486 (18.4%) were stored as transplantable units. We investigated the mother's gestational period, CB volume, total nucleated cells (TNCs), CD34+ cells, total colony-forming units (CFUs), time from collection to reception and cryopreservation, cell viability, and the reasons for not storing a unit.

RESULTS

The average time from collection to reception of 29,795 units was 18.0 h. The most common reason for not storing a CB unit was low cell numbers (pre-processing TNC count <1.2 billion), accounting for 67.9% of the units received. There was no correlation between the CB volume and the CD34+ cell count. The shorter the gestational period, the lower the TNC count, but the higher the CD34+ cell count. There was no correlation between the time from collection to cryopreservation, within a 36-h time limit, and the CD34+ cell recovery rate.

CONCLUSION

We could accept units with a TNC count <1.2 billion and a CB volume <60 mL from a gestational period of 38 weeks or less if we did a pre-processing CD34+ cell count. This would secure more units rich in CD34+ cells.

Evaluation of factors affecting total nucleated cells in umbilical cord blood collected for the Calabria Cord Blood Bank

BACKGROUND

Total nucleated cell (TNC) count is the most important biological feature to consider in assessing the quality of umbilical cord blood (UCB) for hematopoietic stem cell (HSC) transplantation. Certain obstetric factors have been reported to increase TNC count in UCB units collected for transplantation. The aim of our study was to analyze how various maternal, neonatal and obstetric factors affected TNC count in the UCBs we collected for our cord blood bank in southern Italy.

METHODS

We performed a retrospective analysis of 634 medical records of UCBs collected by Calabria Cord Blood Bank (CCBB), Reggio Calabria, Italy, between January 1, 2010, and December 31, 2016. We analyzed various maternal, neonatal and obstetric variables factors and related this factor with the characteristic of TNC.

RESULTS

We found that the average number of TNCs was significantly greater in vaginal delivery than in caesarean delivery. We also found that TNCs were higher in the 40th week of pregnancy and when Apgar 1' scores were ≤9. The effect of a newborn's gender was less evident on TNC count.

CONCLUSIONS

Knowledge of factors predictive of a higher TNC count would help cord blood banks more efficiently identify donors likely to yield high-quality UCBs for transplantation.

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.

Alloengraftment without significant toxicity or GVHD in CD45 antibody-drug conjugate-conditioned Fanconi anemia mice

ABSTRACT

Fanconi anemia (FA) is an inherited DNA repair disorder characterized by bone marrow (BM) failure, developmental abnormalities, myelodysplasia, leukemia, and solid tumor predisposition. Allogeneic hematopoietic stem cell transplantation (allo-HSCT), a mainstay treatment, is limited by conditioning regimen-related toxicity and graft-versus-host disease (GVHD). Antibody-drug conjugates (ADCs) targeting hematopoietic stem cells (HSCs) can open marrow niches permitting donor stem cell alloengraftment. Here, we report that single dose anti-mouse CD45-targeted ADC (CD45-ADC) facilitated stable, multilineage chimerism in 3 distinct FA mouse models representing 90% of FA complementation groups. CD45-ADC profoundly depleted host stem cell enriched Lineage-Sca1+cKit+ cells within 48 hours. Fanca-/- recipients of minor-mismatched BM and single dose CD45-ADC had peripheral blood (PB) mean donor chimerism >90%; donor HSCs alloengraftment was verified in secondary recipients. In Fancc-/- and Fancg-/- recipients of fully allogeneic grafts, PB mean donor chimerism was 60% to 80% and 70% to 80%, respectively. The mean percent donor chimerism in BM and spleen mirrored PB results. CD45-ADC-conditioned mice did not have clinical toxicity. A transient <2.5-fold increase in hepatocellular enzymes and mild-to-moderate histopathological changes were seen. Under GVHD allo-HSCT conditions, wild-type and Fanca-/- recipients of CD45-ADC had markedly reduced GVHD lethality compared with lethal irradiation. Moreover, single dose anti-human CD45-ADC given to rhesus macaque nonhuman primates on days -6 or -10 was at least as myeloablative as lethal irradiation. These data suggest that CD45-ADC can potently promote donor alloengraftment and hematopoiesis without significant toxicity or severe GVHD, as seen with lethal irradiation, providing strong support for clinical trial considerations in highly vulnerable patients with FA.

A comprehensive review on the role of mesenchymal stromal/stem cells in the management of rheumatoid arthritis

INTRODUCTION

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disease with systemic manifestations. Although the success of immune modulatory drug therapy is considerable, about 40% of patients do not respond to treatment. Mesenchymal stromal/stem cells (MSCs) have been demonstrated to have therapeutic potential for inflammatory diseases.

AREAS COVERED

This review provides an update on RA disease and on pre-clinical and clinical studies using MSCs from bone marrow, umbilical cord, adipose tissue, and dental pulp, to regulate the immune response. Moreover, the clinical use, safety, limitations, and future perspective of MSCs in RA are discussed. Using the PubMed database and ClincalTrials.gov, peer-reviewed full-text papers, abstracts and clinical trials were identified from 1985 through to April 2023.

EXPERT OPINION

MSCs demonstrated a satisfactory safety profile and potential for clinical efficacy. However, it is mandatory to deepen the investigations on how MSCs affect the proinflammatory deregulated RA patients' cells. MSCs are potentially good candidates for severe RA patients not responding to conventional therapies but a long-term follow-up after stem cells treatment and standardized protocols are needed. Future research should focus on well-designed multicenter randomized clinical trials with adequate sample sizes and properly selected patients satisfying RA criteria for a valid efficacy evaluation.

The effect of red blood cell disorders on male fertility and reproductive health

Male infertility is defined as a failure to conceive after 12 months of unprotected intercourse owing to suspected male reproductive factors. Non-malignant red blood cell disorders are systemic conditions that have been associated with male infertility with varying severity and strength of evidence. Hereditary haemoglobinopathies and bone marrow failure syndromes have been associated with hypothalamic-pituitary-gonadal axis dysfunction, hypogonadism, and abnormal sperm parameters. Bone marrow transplantation is a potential cure for these conditions, but exposes patients to potentially gonadotoxic chemotherapy and/or radiation that could further impair fertility. Iron imbalance might also reduce male fertility. Thus, disorders of hereditary iron overload can cause iron deposition in tissues that might result in hypogonadism and impaired spermatogenesis, whereas severe iron deficiency can propagate anaemias that decrease gonadotropin release and sperm counts. Reproductive urologists should be included in the comprehensive care of patients with red blood cell disorders, especially when gonadotoxic treatments are being considered, to ensure fertility concerns are appropriately evaluated and managed.

Umbilical Cord Blood Transplantation for Fanconi Anemia With a Special Focus on Late Complications: a Study on Behalf of Eurocord and SAAWP-EBMT

Hematopoietic cell transplantation (HCT) remains the sole available curative treatment for Fanconi anemia (FA), with particularly favorable outcomes reported after matched sibling donor (MSD) HCT. This study aimed to describe outcomes, with a special focus on late complications, of FA patients who underwent umbilical cord blood transplantation (UCBT). In this retrospective analysis of allogeneic UCBT for FA performed between 1988 and 2021 in European Society for Blood and Marrow Transplantation (EBMT)-affiliated centers, a total of 205 FA patients underwent UCBT (55 related and 150 unrelated) across 77 transplant centers. Indications for UCBT were bone marrow failure in 190 patients and acute leukemia/myelodysplasia in 15 patients. The median age at transplantation was 9 years (range, 1.2 to 43 years), with only 20 patients aged >18 years. Among the donor-recipient pairs, 56% (n = 116) had a 0 to 1/6 HLA mismatch. Limited-field radiotherapy was administered to 28% (n = 58) and 78% (n = 160) received a fludarabine (Flu)-based conditioning regimen. Serotherapy consisted of antithymocyte globulin (n = 159; 78%) or alemtuzumab (n = 12; 6%). The median follow-up was 10 years for related UCBT and 7 years for unrelated UCBT. Excellent outcomes were observed in the setting of related UCBT, including a 60-day cumulative incidence (CuI) of neutrophil recovery of 98.1% (95% confidence interval [CI], 93.9% to 100%), a 100-day CuI of grade II-IV acute graft-versus-host disease (GVHD) of 17.3% (95% CI, 9.5% to 31.6%), and a 5-year CuI of chronic GVHD (cGVHD) of 22.7% (95% CI, 13.3% to 38.7%; 13% extensive). Five-year overall survival (OS) was 88%. In multivariate analysis, none of the factors included in the model predicted a better OS. In unrelated UCBT, the 60-day CuI of neutrophil recovery was 78.7% (95% CI, 71.9% to 86.3%), the 100-day CuI of grade II-IV aGVHD was 31.4% (95% CI, 24.6% to 40.2%), and the 5-year CuI of cGVHD was 24.3% (95% CI, 17.8% to 32.2%; 12% extensive). Five-year OS was 44%. In multivariate analysis, negative recipient cytomegalovirus serology, Flu-based conditioning, age <9 years at UCBT, and 0 to 1/6 HLA mismatch were associated with improved OS. A total of 106 patients, including 5 with acute leukemia/myelodysplasia, survived for >2 years after UCBT. Nine of these patients developed subsequent neoplasms (SNs), including 1 donor-derived acute myelogenous leukemia and 8 solid tumors, at a median of 9.7 years (range, 2.3 to 21.8 years) post-UCBT (1 related and 8 unrelated UCBT). In a subset of 49 patients with available data, late nonmalignant complications affecting various organ systems were observed at a median of 8.7 years (range, 2.7 to 28.8 years) post-UCBT. UCB is a valid source of stem cells for transplantation in patients with FA, with the best results observed after related UCBT. After unrelated UCBT, improved survival was observed in patients who underwent transplantation at a younger age, with Flu-based conditioning, and with better HLA parity. The incidence of organ-specific complications and SNs was relatively low. The incidence of SNs, mostly squamous cell carcinoma, increases with time. Rigorous follow-up and lifelong screening are crucial in survivors of UCBT for FA.

Advances in hematopoietic stem cells ex vivo expansion associated with bone marrow niche

Hematopoietic stem cells (HSCs) are an ideal source for the treatment of many hematological diseases and malignancies, as well as diseases of other systems, because of their two important features, self-renewal and multipotential differentiation, which have the ability to rebuild the blood system and immune system of the body. However, so far, the insufficient number of available HSCs, whether from bone marrow (BM), mobilized peripheral blood or umbilical cord blood, is still the main restricting factor for the clinical application. Therefore, strategies to expand HSCs numbers and maintain HSCs functions through ex vivo culture are urgently required. In this review, we outline the basic biology characteristics of HSCs, and focus on the regulatory factors in BM niche affecting the functions of HSCs. Then, we introduce several representative strategies used for HSCs from these three sources ex vivo expansion associated with BM niche. These findings have deepened our understanding of the mechanisms by which HSCs balance self-renewal and differentiation and provided a theoretical basis for the efficient clinical HSCs expansion.

Implications of maternal-fetal health on perinatal stem cell banking

Cell based therapies are being assessed for their therapeutic potential across a variety of diseases. Gestational tissues are attractive sources for cell therapy. The large number of births worldwide ensures sufficient access to gestational tissues, however, limited information has been reported around the impact of birth trends, delivery methods and pregnancy conditions on perinatal stem cell banking. This review describes the current state of banking of gestational tissues and their derived perinatal stem cells, discusses why the changes in birth trends and delivery methods could affect gestational tissue banking practices, and further explores how common pregnancy complications can potentially influence perinatal stem cell banking.

Scoring system for optimal cord blood unit selection for single cord blood transplantation

BACKGROUND

We conducted a retrospective study to categorize the cord blood unit (CBU)s to identify the optimal units.

METHODS

A total of 8503 adults (female, n = 3592; male, n = 4911) receiving their first single cord blood transplantation (CBT) in 2000-2019 were analyzed. Factors associated with CBUs affecting overall survival (OS) and neutrophil engraftment were selected to create ranked categorization for each outcome, followed by comparison with transplantation using HLA-matched bone marrow (BMT)/peripheral blood stem cell (PBSCT) from unrelated (n = 6052) and related donors (n = 4546).

RESULTS

Sex-mismatch, CD34+ cell and CFU-GM counts were selected in the OS analysis. Considering the strong interaction between sex mismatch and CD34+ cell counts, we analyzed females and males separately. For females, female CBU with CD34+ cell counts {greater than or equal to} 0.5 × 10e5/kg and CFU-GM counts {greater than or equal to} 15 × 10e3/kg offered the best OS (Group I), followed by other groups with any (Groups II-IV) or all (Group V) of the risk factors. Group I consistently showed favorable OS (Group IV: HR1.22, P = 0.027; Group V: HR1.31, P = 0.047), comparable to those of rBMT/PBSCT (OS: HR1.02, P = 0.654) and uBM/PBSCT in patients with higher rDRI (HR1.07, P = 0.353). Male patients lacked significant factors affecting OS. Categorization for neutrophil engraftment consisting of CD34+ cell and CFU-GM counts, sex-mismatch, presence of donor-specific antibodies, and the number of HLA-mismatches was effective but not predicted OS.

CONCLUSION

Our ranked categorizations sufficiently predicted female OS and engraftment. The best-ranked CBUs offered preferable outcomes comparable to conventional BM/PB donors in female but not in male patients.

Ex vivo expansion of human hematopoietic stem cells and clinical applications

Hematopoietic stem cells (HSCs) are a rare population of cells found in the bone marrow that play a critical role in lifelong hematopoiesis and the reconstitution of the hematopoietic system after hematopoietic stem cell transplantation. Hematopoietic stem cell transplantation remains the only curative treatment for patients with refractory hematologic disorders, and umbilical cord blood (CB) serves as an alternative stem cell source due to its several advantageous characteristics, including human leukocyte antigen flexibility and reduced donor burden. However, CB also has the disadvantage of containing a small number of cells, resulting in limited donor selection and a longer time for engraftment. Therefore, the development of techniques to expand HSCs ex vivo, particularly umbilical CB, is a goal in hematology. While various combinations of cytokines were once the mainstream approach, these protocols had limited expansion rates and did not lead to clinical application. However, in recent years, the development of a technique in which small molecules are added to cytokines has enabled the stable, long-term ex vivo expansion of human HSCs. Clinical trials of expanded umbilical CB using these techniques have been undertaken and have confirmed their efficacy and safety. In addition, we have successfully developed a recombinant-cytokine-free and albumin-free culture system for the long-term expansion of human HSCs. This approach could offer the potential for more selective expansion of human HSCs compared to previous protocols. This review discusses ex vivo culture protocols for expanding human HSCs and presents the results of clinical trials using these techniques, along with future perspectives.

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.

Outcome of first or second transplantation using unrelated umbilical cord blood without ATG conditioning regimen for pediatric bone marrow failure disorders

BACKGROUND

Unrelated umbilical cord blood transplantation (UCBT) for bone marrow failure (BMF) disorders using conditioning regimens without Anti-Thymocyte Globulin (ATG) has been used as an alternative transplantation for emerging patients without matched-sibling donors. Experience with this transplant modality in children is limited, especially as a secondary treatment for transplant failure patients.

PROCEDURE

We retrospectively reviewed 17 consecutive bone marrow failure patients who underwent unrelated umbilical cord blood transplantation in our center and received conditioning regimens of Total Body Irradiation (TBI) or Busulfan (BU) + Fludarabine (FLU) + Cyclophosphamide (CY).

RESULTS

Among the 17 BMF patients, 15 patients were treated with first cord blood transplantation and another 2 with secondary cord blood transplantation because of graft failure after first haploidentical stem cell transplantation at days +38 and +82. All patients engrafted with a median donor cell chimerism of 50 % at days +7 (range, 16 %-99.95 %) and finally rose to 100 % at days +30. Median time to neutrophil engraftment was 19 days (range, 12-30) and time to platelet engraftment was 32 days (range, 18-61). Pre-engraftment syndrome (PES) was found in 16 patients (94.11 %, 16/17). Cumulative incidence of grades II to IV acute GVHD was 58.8 % (95 % CI: 32.7-84.9 %), and 17.6 % (95 % CI: 2.6-37.9 %) of patients developed chronic GVHD. The 3-year overall survival (OS) and failure-free survival (FFS) rates were 92.86 ± 6.88 %.

CONCLUSION

UCBT is an effective alternative treatment for bone marrow failure pediatric patients. TBI/BU + FLU + CY regimen ensure a high engraftment rate for unrelated umbilical cord blood transplantation, which overcomes the difficulty of graft failure. Secondary salvage use of cord blood transplantation may still be useful for patients who have failed after other transplantation.

Expansion of human hematopoietic stem cells by inhibiting translation

Hematopoietic stem cell (HSC) transplantation using umbilical cord blood (UCB) is a potentially life-saving treatment for leukemia and bone marrow failure but is limited by the low number of HSCs in UCB. The loss of HSCs after ex vivo manipulation is also a major obstacle to gene editing for inherited blood disorders. HSCs require a low rate of translation to maintain their capacity for self-renewal, but hematopoietic cytokines used to expand HSCs stimulate protein synthesis and impair long-term self-renewal. We previously described cytokine-free conditions that maintain but do not expand human and mouse HSCs ex vivo. Here we performed a high throughput screen and identified translation inhibitors that allow ex vivo expansion of human HSCs while minimizing cytokine exposure. Transplantation assays show a ~5-fold expansion of long-term HSCs from UCB after one week of culture in low cytokine conditions. Single cell transcriptomic analysis demonstrates maintenance of HSCs expressing mediators of the unfolded protein stress response, further supporting the importance of regulated proteostasis in HSC maintenance and expansion. This expansion method maintains and expands human HSCs after CRISPR/Cas9 editing of the BCL11A+58 enhancer, overcoming a major obstacle to ex vivo gene correction for human hemoglobinopathies.

Insights into highly engraftable hematopoietic cells from 27-year cryopreserved umbilical cord blood

Umbilical cord blood transplantation is a life-saving treatment for malignant and non-malignant hematologic disorders. It remains unclear how long cryopreserved units remain functional, and the length of cryopreservation is often used as a criterion to exclude older units. We demonstrate that long-term cryopreserved cord blood retains similar numbers of hematopoietic stem and progenitor cells compared with fresh and recently cryopreserved cord blood units. Long-term cryopreserved units contain highly functional cells, yielding robust engraftment in mouse transplantation models. We also leverage differences between units to examine gene programs associated with better engraftment. Transcriptomic analyses reveal that gene programs associated with lineage determination and oxidative stress are enriched in high engrafting cord blood, revealing potential molecular markers to be used as potency markers for cord blood unit selection regardless of length of cryopreservation. In summary, cord blood units cryopreserved for extended periods retain engrafting potential and can potentially be used for patient treatment.

Mitigation of acute radiation syndrome (ARS) with human umbilical cord blood

PURPOSE

The growing concern over potential unintended nuclear accidents or malicious activities involving nuclear/radiological devices cannot be overstated. Exposure to whole-body doses of radiation can result in acute radiation syndrome (ARS), colloquially known as "radiation sickness," which can severely damage various organ systems. Long-term health consequences, such as cancer and cardiovascular disease, can develop many years post-exposure. Identifying effective medical countermeasures and devising a strategic medical plan represents an urgent, unmet need. Various clinical studies have investigated the therapeutic use of umbilical cord blood (UCB) for a range of illnesses, including ARS. The objective of this review is to thoroughly discuss ARS and its sub-syndromes, and to highlight recent findings regarding the use of UCB for radiation injury. UCB, a rich source of stem cells, boasts numerous advantages over other stem cell sources, like bone marrow, owing to its ease of collection and relatively low risk of severe graft-versus-host disease. Preclinical studies suggest that treatment with UCB, and often UCB-derived mesenchymal stromal cells (MSCs), results in improved survival, accelerated hematopoietic recovery, reduced gastrointestinal tract damage, and mitigation of radiation-induced pneumonitis and pulmonary fibrosis. Interestingly, recent evidence suggests that UCB-derived exosomes and their microRNAs (miRNAs) might assist in treating radiation-induced damage, largely by inhibiting fibrotic pathways.

CONCLUSION

UCB holds substantial potential as a radiation countermeasure, and future research should focus on establishing treatment parameters for ARS victims.

Natural killer cells 56bright16- have higher counts in the umbilical cord blood than in the adult peripheral blood

INTRODUCTION AND HYPOTHESIS

Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cells for allogeneic hematopoietic stem cell transplantation in the absence of a compatible donor. The UCB transplantation has a lower incidence of chronic graft versus host disease (GvHD), but is associated with slower engraftment and slower immune reconstitution, compared to other sources. Dendritic cells (DCs) and Natural Killer cells (NKs) play a central role in the development of GvHD and the graft versus leukemia (GvL) effect, as well as in the control of infectious complications.

METHOD

We quantified by multiparametric flow cytometry monocytes, lymphocytes, NK cells, and DCs, including their subsets, in UCB samples from 54 healthy newborns and peripheral blood (PB) from 25 healthy adult volunteers.

RESULTS

In the UCB samples, there were higher counts of NK cells 56bright16- (median 0.024 × 109/L), compared to the PB samples (0.012 × 109/L, p < 0.0001), NK 56dim16bright (median 0.446 × 109/L vs. 0.259 × 109/L for PB samples, p = 0.001) and plasmacytoid dendritic cells (pDCs, median 0.008 × 109/L for UCB samples vs. 0.006 × 109/L for PB samples, p = 0.03). Moreover, non-classic monocyte counts were lower in UCB than in PB (median 0.024 × 109/L vs. 0.051 × 109/L, respectively, p < 0.0001).

CONCLUSION

In conclusion, there were higher counts of NK cells and pDCs and lower counts of non-classic monocytes in UCB than in PB from healthy individuals. These findings might explain the lower incidence and severity of chronic GvHD, although maintaining the GvL effect, in UCB transplant recipients, compared to other stem cell sources.

Immunology of cord blood T-cells favors augmented disease response during clinical pediatric stem cell transplantation for acute leukemia

Allogeneic hematopoietic stem cell transplantation (HSCT) has been an important and efficacious treatment for acute leukemia in children for over 60 years. It works primarily through the graft-vs.-leukemia (GVL) effect, in which donor T-cells and other immune cells act to eliminate residual leukemia. Cord blood is an alternative source of stem cells for transplantation, with distinct biological and immunological characteristics. Retrospective clinical studies report superior relapse rates with cord blood transplantation (CBT), when compared to other stem cell sources, particularly for patients with high-risk leukemia. Xenograft models also support the superiority of cord blood T-cells in eradicating malignancy, when compared to those derived from peripheral blood. Conversely, CBT has historically been associated with an increased risk of transplant-related mortality (TRM) and morbidity, particularly from infection. Here we discuss clinical aspects of CBT, the unique immunology of cord blood T-cells, their role in the GVL effect and future methods to maximize their utility in cellular therapies for leukemia, honing and harnessing their antitumor properties whilst managing the risks of TRM.

Unravelling human hematopoietic progenitor cell diversity through association with intrinsic regulatory factors

Hematopoietic stem and progenitor cell (HSPC) transplantation is an essential therapy for hematological conditions, but finer definitions of human HSPC subsets with associated function could enable better tuning of grafts and more routine, lower-risk application. To deeply phenotype HSPCs, following a screen of 328 antigens, we quantified 41 surface proteins and functional regulators on millions of CD34+ and CD34- cells, spanning four primary human hematopoietic tissues: bone marrow, mobilized peripheral blood, cord blood, and fetal liver. We propose more granular definitions of HSPC subsets and provide new, detailed differentiation trajectories of erythroid and myeloid lineages. These aspects of our revised human hematopoietic model were validated with corresponding epigenetic analysis and in vitro clonal differentiation assays. Overall, we demonstrate the utility of using molecular regulators as surrogates for cellular identity and functional potential, providing a framework for description, prospective isolation, and cross-tissue comparison of HSPCs in humans.

A new beginning: can omidubicel emerge as the next, viable alternative donor source?

Umbilical cord blood (UCB) transplantation (CBT) has been an important alternative donor option for patients lacking matched related donor (MRD) or unrelated donor (URD) grafts. Only 30% of patients with high-risk hematologic malignancies have a human leukocyte antigen (HLA)-identical sibling; subjects without a MRD option are referred for HLA-matched URD selection, or utilize alternative donor sources such as HLA-mismatched URD, UCB, or haploidentical donor grafts. While CBT demonstrates an excellent graft-versus-leukemia (GVL) effect, use of UCB as a graft source is limited due to a lower cell dose that can result in delayed engraftment and an immature immune system with increased infectious risk as a consequence. Together, increased transplant related mortality (TRM) has been associated with UCB allografts. Omidubicel is an ex vivo expanded single cord blood product that has demonstrated rapid engraftment, improved immune reconstitution, and reduced infectious complications in clinical trials. Omidubicel has now been granted U.S. Food & Drug Administration approval to enhance neutrophil recovery and decrease infectious risk. This review will focus on CBT, benefits and barriers to using this alternative donor source, and finally the potential advancements with incorporation of omidubicel in the transplant setting for malignant and non-malignant diseases.

Fresh Umbilical Cord Blood-A Source of Multipotent Stem Cells, Collection, Banking, Cryopreservation, and Ethical Concerns

Umbilical cord blood (UCB) is a rich source of hematopoietic cells that can be used to replace bone marrow components. Many blood disorders and systemic illnesses are increasingly being treated with stem cells as regenerative medical therapy. Presently, collected blood has been stored in either public or private banks for allogenic or autologous transplantation. Using a specific keyword, we used the English language to search for relevant articles in SCOPUS and PubMed databases over time frame. According to our review, Asian countries are increasingly using UCB preservation for future use as regenerative medicine, and existing studies indicate that this trend will continue. This recent literature review explains the methodology of UCB collection, banking, and cryopreservation for future clinical use. Between 2010 and 2022, 10,054 UCB stem cell samples were effectively cryopreserved. Furthermore, we have discussed using Mesenchymal Stem Cells (MSCs) as transplant medicine, and its clinical applications. It is essential for healthcare personnel, particularly those working in labor rooms, to comprehend the protocols for collecting, transporting, and storing UCB. This review aims to provide a glimpse of the details about the UCB collection and banking processes, its benefits, and the use of UCB-derived stem cells in clinical practice, as well as the ethical concerns associated with UCB, all of which are important for healthcare professionals, particularly those working in maternity wards; namely, the obstetrician, neonatologist, and anyone involved in perinatal care. This article also highlights the practical and ethical concerns associated with private UCB banks, and the existence of public banks. UCB may continue to grow to assist healthcare teams worldwide in treating various metabolic, hematological, and immunodeficiency disorders.

Umbilical cord blood derived cellular therapy: advances in clinical development

While cord blood (CB) is primarily utilized in allogeneic hematopoietic cell transplantation (HCT), the development of novel cell therapy products from CB is a growing and developing field. Compared to adult blood, CB is characterized by a higher percentage of hematopoietic stem cells (HSCs) and progenitor cells, less mature immune cells that retain a high capacity of proliferation, and stronger immune tolerance that requires less stringent HLA-matching when used in the allogenic setting. Given that CB is an FDA regulated product and along with its unique cellular composition, CB lends itself as a readily available and safe starting material for the development of off-the-shelf cell therapies. Moreover, non-hematologic cells such as mesenchymal stem cell (MSCs) residing in CB or CB tissue also have potential in regenerative medicine and inflammatory and autoimmune conditions. In this review, we will focus on recent clinical development on CB-derived cellular therapies in the field of oncology, including T-cell therapies such as chimeric antigen receptor (CAR) T-cells, regulatory T-cells, and virus-specific T-cells; NK-cell therapies, such as NK cell engagers and CAR NK-cells; CB-HCT and various modifications; as well as applications of MSCs in HCT.

Immune Reconstitution Profiling Suggests Antiviral Protection After Transplantation with Omidubicel: a Phase 3 Substudy

BACKGROUND

Allogeneic hematopoietic cell transplantation (HCT) is a potentially curative treatment for hematological malignancies and non-malignant disorders. Rapid immune reconstitution (IR) following allogeneic HCT has been shown to be associated with improved clinical outcomes and lower infection rates. A global phase 3 trial (NCT02730299) of omidubicel, an advanced cell therapy manufactured from an appropriately human leukocyte antigen-matched single umbilical cord blood (UCB) unit, showed faster hematopoietic recovery, reduced rates of infection, and shorter hospitalizations in patients randomized to omidubicel compared with those randomized to standard UCB.

OBJECTIVE

This optional, prospective substudy of the phase 3 trial characterized the IR kinetics following HCT with omidubicel compared with UCB in a systematic and detailed manner.

STUDY DESIGN

In this substudy, 37 patients from 14 global sites were included (omidubicel: n=17, UCB: n=20). Peripheral blood samples were collected over 10 predefined time points from 7 to 365 days post-HCT. Flow cytometry immunophenotyping, T cell receptor excision circle quantification, and T cell receptor sequencing were employed to evaluate the longitudinal IR kinetics post-transplant and their association with clinical outcomes.

RESULTS

Patient characteristics in the two comparator cohorts were overall statistically similar, except for age and total body irradiation (TBI) based conditioning regimens. The median age (range) for patients who received omidubicel or UCB was 30 (13-62) years and 43 (19-55) years, respectively. The percentages of patients receiving TBI based conditioning regimens were 47% and 70% for omidubicel and UCB recipients, respectively. Graft characteristics differed in their cellular composition. Omidubicel recipients received a 33-fold higher median dose of CD34+ stem cells, while receiving one third of the median CD3+ lymphocyte dose infused to UCB transplanted patients. Compared with UCB, omidubicel recipients exhibited faster IR of all measured lymphoid and myelomonocytic subpopulations, predominantly in the first 14 days post-transplant. This effect involved circulating natural killer (NK) cells, helper T cells, monocytes, and dendritic cells, with superior long-term B cell recovery from Day 28. One-week post-HCT, omidubicel recipients exhibited 4.1 and 7.7 -fold increases in the median helper T and NK cell counts respectively, compared to their UCB transplanted counterparts. By three weeks post-HCT, omidubicel transplanted patients were 3-fold more likely to achieve clinically relevant helper T and NK cell counts of 100 cells/ µL or above. Similar to UCB, omidubicel yielded a balanced cellular subpopulation composition and diverse T cell receptor repertoire in the short to long term. Omidubicel's CD34+ cell content correlated with faster IR by Day 7 post-HCT, which in turn coincided with earlier hematopoietic recovery. Lastly, early NK and helper T cell reconstitution correlated with a decreased rate of post-HCT viral infections, suggesting a plausible explanation for this phenomenon among omidubicel recipients in the phase 3 study.

CONCLUSIONS

Our findings suggest that omidubicel efficiently promotes IR across multiple immune cells, including CD4+ T cells, B cells, NK cells, and dendritic cell subtypes as early as 7 days post-transplant, potentially endowing recipients of omidubicel with early protective immunity.

Umbilical Cord Blood Transplantation: Connecting Its Origin to Its Future

Transplantation of umbilical cord blood (UCB) is an attractive alternative source of hematopoietic stem cells (HSCs). The unique properties of cord blood and its distinct immune tolerance and engraftment kinetics compared to bone marrow (BM) and peripheral blood progenitor cells, permit a wider disparity in human leukocyte antigen levels between a cord blood donor and recipient after an unrelated umbilical cord blood transplant (UCBT). In addition, it is readily available and has a lowered risk of graft-versus-host disease (GvHD), with similar long-term clinical outcomes, compared to BM transplants. However, the relatively low number of cells administered by UCB units, as well as the associated delayed engraftment and immune reconstitution, pose limitations to the wide application of UCBT. Research into several aspects of UCBT has been evaluated, including the ex vivo expansion of cord blood HSCs and the process of fucosylation to enhance engraftment. Additionally, UCB has also been used in the treatment of several neurodegenerative and cardiovascular disorders with varying degrees of success. In this article, we will discuss the biology, clinical indications, and benefits of UCBT in pediatric and adult populations. We will also discuss future directions for the use of cord blood.

Chemically defined cytokine-free expansion of human haematopoietic stem cells

Haematopoietic stem cells (HSCs) are a rare cell type that reconstitute the entire blood and immune systems after transplantation and can be used as a curative cell therapy for a variety of haematological diseases1,2. However, the low number of HSCs in the body makes both biological analyses and clinical application difficult, and the limited extent to which human HSCs can be expanded ex vivo remains a substantial barrier to the wider and safer therapeutic use of HSC transplantation3. Although various reagents have been tested in attempts to stimulate the expansion of human HSCs, cytokines have long been thought to be essential for supporting HSCs ex vivo4. Here we report the establishment of a culture system that allows the long-term ex vivo expansion of human HSCs, achieved through the complete replacement of exogenous cytokines and albumin with chemical agonists and a caprolactam-based polymer. A phosphoinositide 3-kinase activator, in combination with a thrombopoietin-receptor agonist and the pyrimidoindole derivative UM171, were sufficient to stimulate the expansion of umbilical cord blood HSCs that are capable of serial engraftment in xenotransplantation assays. Ex vivo HSC expansion was further supported by split-clone transplantation assays and single-cell RNA-sequencing analysis. Our chemically defined expansion culture system will help to advance clinical HSC therapies.

Therapeutical growth in oligodendroglial fate induction via transdifferentiation of stem cells for neuroregenerative therapy

The merits of stem cell therapy and research are undisputed due to their widespread usage in the treatment of neurodegenerative diseases and demyelinating disorders. Cell replacement therapy especially revolves around stem cells and their induction into different cell lineages both adult and progenitor - belonging to each germ layer, prior to transplantation or disease modeling studies. The nervous system is abundant in glial cells and among these are oligodendrocytes capable of myelinating new-born neurons and remyelination of axons with lost or damaged myelin sheath. But demyelinating diseases generate tremendous deficit between myelin loss and recovery. To compensate for this loss, analyze the defects in remyelination mechanisms as well as to trigger full recovery in such patients mesenchymal stem cells (MSCs) have been induced to transdifferentiate into oligodendrocytes. But such experiments are riddled with problems like prolonged, tenuous and complicated protocols that stretch longer than the time taken for the spread of demyelination-associated after-effects. This review delves into such protocols and the combinations of different molecules and factors that have been recruited to derive bona fide oligodendrocytes from in vitro differentiation of embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs) and MSCs with special focus on MSC-derived oligodendrocytes.

Cellular Therapies: Yesterday, Today, and Tomorrow

Cellular therapy (CT) can be defined as the transference into a person of healthy cells to correct defective functions. Yesterday (1950-2010), CT consisted mostly of hematopoietic transplants for the treatment of a variety of hematological disorders. Interestingly, during that period of time other cell types with therapeutic potential-including certain lymphoid populations and other nonhematopoietic cells-were discovered and characterized; thus, CT became a promising discipline for the treatment of a broader diversity of diseases. Today (2011-2023), CT has significantly grownup through preclinical studies and clinical trials, and it is currently progressing toward its consolidation as one of the pillars of medicine in the 21st century. Indeed, different types of stem cells (e.g., hematopoietic, mesenchymal, neural, and pluripotent), as well as different lymphoid and myeloid cell populations (e.g., TILs, CAR-Ts, CAR-NKs, and DUOC-01) are being used in clinical settings or are being tested in clinical trials. For the past decade, several CT modalities have been developed, and today, many of them are being used in the clinic. Tomorrow (2024-2040), already established CT modalities will surely be improved and applied more frequently, and novel therapies (that will include cell types such as iPSCs) will enter and expand within the clinical ground. It is noteworthy, however, that despite significant advancements and achievements, problems still need to be solved and obstacles need to be overcome. Technical, ethical, and economic issues persist and they need to be addressed. Undoubtedly, exciting times of challenges and opportunities are coming ahead in the CT arena.

Very small embryonic-like stem cells have the potential to win the three-front war on tissue damage, cancer, and aging

The concept of dedifferentiation and reprogramming of mature somatic cells holds much promise for the three-front "war" against tissue damage, cancer, and aging. It was hoped that reprogramming human somatic cells into the induced pluripotent state, along with the use of embryonic stem cells, would transform regenerative medicine. However, despite global efforts, clinical applications remain a distant dream, due to associated factors such as genomic instability, tumorigenicity, immunogenicity, and heterogeneity. Meanwhile, the expression of embryonic (pluripotent) markers in multiple cancers has baffled the scientific community, and it has been suggested that somatic cells dedifferentiate and "reprogram" into the pluripotent state in vivo to initiate cancer. It has also been suggested that aging can be reversed by partial reprogramming in vivo. However, better methods are needed; using vectors or Yamanaka factors in vivo, for example, is dangerous, and many potential anti-aging therapies carry the same risks as those using induced pluripotent cells, as described above. The present perspective examines the potential of endogenous, pluripotent very small embryonic-like stem cells (VSELs). These cells are naturally present in multiple tissues; they routinely replace diseased tissue and ensure regeneration to maintain life-long homeostasis, and they have the ability to differentiate into adult counterparts. Recent evidence suggests that cancers initiate due to the selective expansion of epigenetically altered VSELs and their blocked differentiation. Furthermore, VSEL numbers have been directly linked to lifespan in studies of long- and short-lived transgenic mice, and VSEL dysfunction has been found in the ovaries of aged mice. To conclude, a greater interest in VSELs, with their potential to address all three fronts of this war, could be the "light at the end of the tunnel."

Ex Vivo Expansion and Homing of Human Cord Blood Hematopoietic Stem Cells

Cord blood (CB) has been proven to be an alternative source of haematopoietic stem cells (HSCs) for clinical transplantation and has multiple advantages, including but not limited to greater HLA compatibility, lower incidence of graft-versus-host disease (GvHD), higher survival rates and lower relapse rates among patients with minimal residual disease. However, the limited number of HSCs in a single CB unit limits the wider use of CB in clinical treatment. Many efforts have been made to enhance the efficacy of CB HSC transplantation, particularly by ex vivo expansion or enhancing the homing efficiency of HSCs. In this chapter, we will document the major advances regarding human HSC ex vivo expansion and homing and will also discuss the possibility of clinical translation of such laboratory work.

Therapeutic Perspectives for the Clinical Application of Umbilical Cord Hematopoietic and Mesenchymal Stem Cells: Overcoming Complications Arising After Allogeneic Hematopoietic Stem Cell Transplantation

This review focuses on the therapeutic features of umbilical cord blood (UCB) cells as a source for allogeneic hematopoietic stem cell transplantation (aHSCT) in adult and child populations to treat malignant and nonmalignant hematologic diseases, genetic disorders, or pathologies of the immune system, when standard treatment (e.g., chemotherapy) is not effective or clinically contraindicated. In this article, we summarize the immunological properties and the advantages and disadvantages of using UCB stem cells and discuss a variety of treatment outcomes using different sources of stem cells from different donors both in adults and pediatric population. We also highlight the critical properties (total nucleated cell dose depending on HLA compatibility) of UCB cells that reach better survival rates, reveal the advantages of double versus single cord blood unit transplantation, and present recommendations from the most recent studies. Moreover, we summarize the mechanism of action and potential benefit of mesenchymal umbilical cord cells and indicate the most common posttransplantation complications.

Recent clinical trials with stem cells to slow or reverse normal aging processes

Aging is associated with a decline in the regenerative potential of stem cells. In recent years, several clinical trials have been launched in order to evaluate the efficacy of mesenchymal stem cell interventions to slow or reverse normal aging processes (aging conditions). Information concerning those clinical trials was extracted from national and international databases (United States, EU, China, Japan, and World Health Organization). Mesenchymal stem cell preparations were in development for two main aging conditions: physical frailty and facial skin aging. With regard to physical frailty, positive results have been obtained in phase II studies with intravenous Lomecel-B (an allogeneic bone marrow stem cell preparation), and a phase I/II study with an allogeneic preparation of umbilical cord-derived stem cells was recently completed. With regard to facial skin aging, positive results have been obtained with an autologous preparation of adipose-derived stem cells. A further sixteen clinical trials for physical frailty and facial skin aging are currently underway. Reducing physical frailty with intravenous mesenchymal stem cell administration can increase healthy life expectancy and decrease costs to the public health system. However, intravenous administration runs the risk of entrapment of the stem cells in the lungs (and could raise safety concerns). In addition to aesthetic purposes, clinical research on facial skin aging allows direct evaluation of tissue regeneration using sophisticated and precise methods. Therefore, research on both conditions is complementary, which facilitates a global vision.

An overview of cord blood stem cell transplantation in Hong Kong

Haematopoietic stem cell graft derived from cord blood is standard therapy for several haematological malignancies and other diseases. The study reports cases of public and private (family) cord blood biobanking services and the related hematopoietic stem cell transplantation ever performed in Hong Kong. The published original research papers and review articles from inception to Nov 2022 have been searched for on Pubmed, Microsoft Academic Search, and Google Scholar to identify reports on existing or terminated cord blood biobanking and transplantation service in Hong Kong. Moreover, all data publicly available on the official websites of the local cord blood banks and local mainstream media has been analysed. The public Hong Kong Red Cross Blood Transfusion Service delivers the highest quantity of haematopoietic stem cell transplants. Among the private sector, HealthBaby releases the most cord blood units for clinical use in diseases in both autologous and allogeneic administration, followed by Cordlife HK.  Both public and private (family) cord blood biobanks have been and continue to contribute to the Hong Kong cord blood donor registry. However, the growth of the cord blood inventory is detrimental to donor-recipient matching for lifesaving therapy.

Study on promoting the regeneration of grafted fat by cell-assisted lipotransfer

Background

Cell-assisted lipotransfer (CAL), a modified adipose-derived stromal/stem cells (ADSCs)-based approach for autologous fat grafting that is an ideal option for soft tissue augmentation, has many shortcomings in terms of retention and adverse effects. The objective of our study was to improve the treatment efficacy of CAL by adding fibroblasts.

Methods

ADSCs and fibroblasts were isolated from human adipose and dermal tissues, with fibroblasts identified by immunofluorescence and ADSCs identified by the multilineage differentiation method. We performed cell proliferation, apoptosis, migration, adipogenic, and hemangioendothelial differentiation experiments, qPCR and Western blotting analysis in co-cultures of fibroblasts and ADSCs. Subsequently, we conducted animal experiments with BALB/c nude mice. Masson's staining, immunofluorescence staining and ultrasound were used to analyze the occurrence of adverse reactions of the grafted fat, and CT and three-dimensional reconstruction were used to accurately evaluate the volume of the grafted fat.

Results

We found that the co-culture of fibroblasts and ADSCs promoted their mutual proliferation, adipogenic differentiation, hemangioendothelial differentiation and proliferation and migration of HUVECs. Fibroblasts inhibit the apoptosis of ADSCs. Moreover, in animal experiments, the autografted adipose group combined with ADSCs and fibroblasts had the least occurrence of oily cysts, and fat had the best form of survival.

Conclusions

We enhanced adipocyte regeneration and angiogenesis in ADSCs and fibroblast cells after adding fibroblasts to conventional CAL autologous fat grafts. In turn, the volume retention rate of the grafted fat is improved, and the adverse reactions are reduced.

Transplantation in CML in the TKI era: who, when, and how?

Molecular therapy with tyrosine kinase inhibitors (TKIs) has significantly reduced the indication for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in chronic myeloid leukemia (CML). Treatment-free remission can be obtained in about 50% of patients with an optimal response. However, cure rates up to 90% are restricted to patients receiving HSCT. Timing is essential since HSCT in the early stages of the disease has the best outcome. Patients in a more advanced phase (AdP) than chronic-phase (chP) CML undergo HSCT with suboptimal outcomes, and the gap between chP and AdP disease is widening. First-line therapy should start with first- or second-generation (G) TKIs. Patients failing treatment (BCR-ABL1 transcripts of greater than 10% at 3 and 6 months and greater than 1% at 12 months) should be switched to second-line TKIs, and HSCT should be considered. Patients not responding to 2G-TKI therapy as well as patients in an accelerated phase (AP) or blast crisis (BC) are candidates for HSCT. Therapy resistant BCR-ABL1 mutations, high-risk additional cytogenetic abnormalities, and molecular signs of leukemia progression should trigger the indication for HSCT. Patients who, despite dose adjustments, do not tolerate or develop severe adverse events, including vascular events, to multiple TKIs are also candidates for HSCT. In AdP CML, TKIs do not show long-lasting results, and the outcome of HSCT is less optimal without pretransplant therapy. In these patients the induction of chP2 with TKIs, either alone (AP) or in combination with intensive chemotherapy (BC), followed by HSCT should be pursued.

Advanced Cell Therapy: Beyond the last Frontier in the Treatment of Cancer. A Historical Perspective Emphasizing the Work of Nobel Prize Laureates

During the last five decades different therapies have been developed for the treatment of cancer, and as a result, patients can now live longer and better lives. Among such therapies, hematopoietic cell transplantation and immunotherapy have played key roles. In this short article, we present our particular point of view on the development of these two cellular therapies. We have focused on a historical perspective emphasizing the work of some of the Nobel Prize winners whose studies constituted cornerstones in our knowledge of the biology of cancer and in our fight against this devastating disease.

Incidence and risk factors for graft failure in the modern era of cord blood transplantation

BACKGROUND AND OBJECTIVES

Graft failure (GF) after cord blood transplant (CBT) has decreased with improved supportive care and cord selection strategies. We aimed to evaluate cord blood selection and factors associated with retransplantation on the incidence of GF, determine risk factors for GF including host antibodies to Kell antigen and evaluate survival after GF.

MATERIALS AND METHODS

We retrospectively reviewed 84 patients who underwent CBT at the University of Oklahoma between 2000 and 2016 and compared outcomes in patients with/without engraftment by Day 28. The nonengraftment cohort was further divided into patients who underwent retransplantation. Kaplan-Meier curves with log-rank tests were calculated to assess the association between mortality and engraftment.

RESULTS

Engraftment following CBT was high at 81%, with 52% engrafting by Day 28 and an additional 29% engrafting by a median of 36 days. Retransplantation led to 88% engraftment at a median of 53 days. Overall, 75% of the 40 patients who did not engraft by Day 28 died. Female sex and total nucleated cell count < 3.5/kg were significantly associated with lack of engraftment and higher mortality. Antibodies to Kell fetal antigen were not identified. Retransplantation by Day 28 for primary GF conferred a survival advantage.

CONCLUSION

This study demonstrates that failure to engraft by 28 days was associated with increased mortality, and risk was mitigated with early retransplantation. Female sex and low total cell dose were associated with increased mortality. Early identification of GF coupled with early retransplantation can reduce mortality in CBT.

Controversies and expectations for the prevention of GVHD: A biological and clinical perspective

Severe acute and chronic graft versus host disease (GVHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic cell transplantation. Historically, cord blood and matched sibling transplantation has been associated with the lowest rates of GVHD. Newer methods have modified the lymphocyte components to minimize alloimmunity, including: anti-thymocyte globulin, post-transplant cyclophosphamide, alpha/beta T cell depletion, and abatacept. These agents have shown promise in reducing severe GVHD, however, can be associated with increased risks of relapse, graft failure, infections, and delayed immune reconstitution. Nonetheless, these GVHD prophylaxis strategies have permitted expansion of donor sources, especially critical for those of non-Caucasian decent who previously lacked transplant options. This review will focus on the biologic mechanisms driving GVHD, the method by which each agent impacts these activated pathways, and the clinical consequences of these modern prophylaxis approaches. In addition, emerging novel targeted strategies will be described. These GVHD prophylaxis approaches have revolutionized our ability to increase access to transplant and have provided important insights into the biology of GVHD and immune reconstitution.

Cytomegalovirus-Specific T Cells from Third-Party Donors Successfully Treated Refractory Cytomegalovirus Retinitis after Unrelated Umbilical Cord Blood Transplantation

Umbilical cord blood (UCB) transplants (UCBTs) are becoming increasingly common in the treatment of a variety of hematologic and nonhematologic conditions. The T cells from UCB are naïve T cells, which have not yet been exposed to antigens and therefore do not contain T cells with specific immune functions against viruses. Cytomegalovirus (CMV) infections occur in more than 80% of patients after UCBT compared to other types of transplantation. Anti-CMV medications are currently restricted, with ganciclovir, foscarnet, and valganciclovir being the most common in China; however, with limited efficacy and considerable side effects, all these drugs are susceptible to viral resistance. In recent years, cytomegalovirus-specific T cells (CMVST) have advanced the treatment of viral infections in immunodeficient patients. CMVST usually uses the same donor as hematopoietic stem cell transplantation. CMVST should be administered to UCBT patients because of the absence of donors after UCBT. In China, there is no report on the use of CMVST to treat CMV infection after UCBT, and foreign reports are also limited. This paper reported a 20-year-old male patient with acute myeloid leukemia who developed cytomegalovirus retinitis (CMVR) after umbilical cord blood transplantation. After ineffective viral treatment, he was treated with a third-party donor CMVST and was successfully transformed into CMV nucleic acid negative.

Umbilical cord mesenchymal stromal cells—from bench to bedside

In recent years, mesenchymal stromal cells (MSCs) have generated a lot of attention due to their paracrine and immuno-modulatory properties. mesenchymal stromal cells derived from the umbilical cord (UC) are becoming increasingly recognized as having increased therapeutic potential when compared to mesenchymal stromal cells from other sources. The purpose of this review is to provide an overview of the various compartments of umbilical cord tissue from which mesenchymal stromal cells can be isolated, the differences and similarities with respect to their regenerative and immuno-modulatory properties, as well as the single cell transcriptomic profiles of in vitro expanded and freshly isolated umbilical cord-mesenchymal stromal cells. In addition, we discuss the therapeutic potential and biodistribution of umbilical cord-mesenchymal stromal cells following systemic administration while providing an overview of pre-clinical and clinical trials involving umbilical cord-mesenchymal stromal cells and their associated secretome and extracellular vesicles (EVs). The clinical applications of umbilical cord-mesenchymal stromal cells are also discussed, especially in relation to obstacles and potential solutions for their effective translation from bench to bedside.

Current status of umbilical cord blood storage and provision to private biobanks by institutions handling childbirth in Japan

Background

The Act Regarding the Promotion of the Appropriate Supply of Hematopoietic Stem Cells for Transplant regulates only how public banks store and provide umbilical cord blood (UCB) for research or transplantation. Japan had no laws to regulate how the private banks manage the procedures, harvesting, preparation, and storage of such blood. As a result, the status of UCB distribution remains unknown. We conducted a survey to investigate the current status of UCB storage and provision to private biobanks by Japanese institutions that handle childbirth.

Methods

Questionnaire forms were mailed to 3,277 facilities handling childbirth that were registered in the Japan Council for Quality Health Care website.

Results

Of the 1,192 institutions handling childbirth that participated in the survey (response rate: 36.7%), 34.4% responded that they currently provide UCB to private biobanks, while 16.1% of facilities did so in the past. Moreover, some institutions currently provide or formerly provided UCB to medical treatment facilities (2.6%), research institutions (5.9%), companies (2.2%), or overseas treatment facilities, research institutions, or companies (0.3%). A certain number of institutions handling childbirth did not even provide explanations or obtain consent when the UCB was harvested from private bank users.

Conclusions

This is the first study to determine the status of UCB provision to private banks by Japanese institutions handling childbirth. Future studies will need to examine in detail how institutions handling childbirth provide explanations to private bank users and UCB providers as well as how these institutions obtain consent.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12910-022-00830-8.

Stem cells: a comprehensive review of origins and emerging clinical roles in medical practice

Stem cells are types of cells that have unique ability to self-renew and to differentiate into more than one cell lineage. They are considered building blocks of tissues and organs. Over recent decades, they have been studied and utilized for repair and regenerative medicine. One way to classify these cells is based on their differentiation capacity. Totipotent stem cells can give rise to any cell of an embryo but also to extra-embryonic tissue as well. Pluripotent stem cells are limited to any of the three embryonic germ layers; however, they cannot differentiate into extra-embryonic tissue. Multipotent stem cells can only differentiate into one germ line tissue. Oligopotent and unipotent stem cells are seen in adult organ tissues that have committed to a cell lineage. Another way to differentiate these cells is based on their origins. Stem cells can be extracted from different sources, including bone marrow, amniotic cells, adipose tissue, umbilical cord, and placental tissue. Stem cells began their role in modern regenerative medicine in the 1950's with the first bone marrow transplantation occurring in 1956. Stem cell therapies are at present indicated for a range of clinical conditions beyond traditional origins to treat genetic blood diseases and have seen substantial success. In this regard, emerging use for stem cells is their potential to treat pain states and neurodegenerative diseases such as Parkinson's and Alzheimer's disease. Stem cells offer hope in neurodegeneration to replace neurons damaged during certain disease states. This review compares stem cells arising from these different sources of origin and include clinical roles for stem cells in modern medical practice.

Multicenter evaluation of the IL-3-pSTAT5 assay to assess the potency of cryopreserved stem cells from cord blood units: The BEST Collaborative study

BACKGROUND

The IL-3-pSTAT5 assay, a new, rapid, and standardized flow-cytometry-based assay may compensate for several limitations of the colony-forming unit (CFU) assay typically used for stem cell potency assessments of cord blood units (CBU). We performed an inter-laboratory evaluation of the performance of this new assay.

STUDY DESIGN AND METHODS

This Biomedical Excellence for Safer Transfusion (BEST) Collaborative multicenter, international study included 15 participants from public cord blood banks (CBBs), CBB-supporting research laboratories, and stem cell laboratories. To perform the IL-3-pSTAT5 assay, participating centers received reagents, instructions, and 10 blind CBU samples, including eight normal samples and two samples exposed to a transient warming event. We measured inter-laboratory agreement qualitatively (proportion of correctly classified samples) and quantitatively (coefficient of variation [CV], correlation coefficients, receiver operating characteristics (ROC) curve, and intraclass correlation coefficient [ICC]).

RESULTS

The qualitative agreement was 97.3% (i.e., 107/110; Fleiss' kappa = 0.835). The average CV on a per-sample basis was 11.57% among all samples, 8.99% among normal samples, and on a per-center basis was 9.42% among normal samples. In a correlation matrix that compared results across centers, the mean Pearson's correlation coefficient was 0.88 (standard deviation = 0.04). The ICC was 0.83 (95% confidence interval = 0.68-0.95). The area under the curve (AUC) from the ROC curve was 0.9974.

DISCUSSION

Excellent qualitative and quantitative agreement was exhibited across laboratories. The IL-3-pSTAT5 assay may therefore be implemented in flow cytometry laboratories to rapidly and reliably provide standardized measures of stem cell potency in CBUs.

Bioengineered 3D microfibrous-matrix modulates osteopontin release from MSCs and facilitates the expansion of hematopoietic stem cells

The osteopontin released from mesenchymal stem cells (MSC) undergoing lineage differentiation can negatively influence the expansion of hematopoietic stem cells (HSCs) in co-culture systems developed for expanding HSCs. Therefore, minimising the amount of osteopontin in the co-culture system is important for the successful ex vivo expansion of HSCs. Towards this goal, a bioengineered 3D microfibrous-matrix that can maintain MSCs in less osteopontin-releasing conditions has been developed, and its influence on the expansion of HSCs has been studied. The newly developed 3D matrix significantly decreased the release of osteopontin, depending on the MSC culture conditions used during the priming period before HSC seeding. The culture system with the lowest amount of osteopontin facilitated a more than 24-fold increase in HSC number in 1 week time period. Interestingly, the viability of expanded cells and the CD34+ pure population of HSCs were found to be the highest in the low osteopontin-containing system. Therefore, bioengineered microfibrous 3D matrices seeded with MSCs, primed under suitable culture conditions, can be an improved ex vivo expansion system for HSC culture. This article is protected by copyright. All rights reserved.

Predictors of cord blood unit cell content in a volume unrestricted large series collections: a chance for a fast and cheap multiparameter selection model

Background

Cord blood plays a very important role in stem cell transplantation and therapy with an emerging implication also in regenerative medicine. The number of cells available in a single cord blood unit (CBU), in particular, the CD34+ and total nucleated cell (TNC) content influences the transplantation clinical outcome. We analysed a very large series of CBUs, collected for private banking without any specific volume restriction, to deeply investigate the best predictors of cord blood stem cells content.

Methods

Maternal and neonatal clinic laboratory data of a total 2583 UCBs were obtained from the InScientiaFides cord blood bank based in Republic of San Marino. Univariate and multivariate analysis were conducted to better interpret the data and to build a predictive model to select, the CBU with high CD34+ content.

Results

Our univariate analysis shows that seasonality and the geographical area affects the quality of umbilical cord blood. Gestational age, babie’s gender and birth weight have a positive correlation with CB TNC content. The babie’s birth weight affects positively also CD34+ content and CBU volume while the cesarean delivery affect the CB volume only. Our predictive model, based on multivariate analysis, shows that male babie’s, gestational age lower to 39 weeks, cesarean delivery and CBUs with a content of TNC higher than 3.44 × 10⁸ (group A) have a significant higher CD34+ content than group B (female babie’s, gestational age higher than 39 weeks and vaginal delivery). The group A have a 37.5% of CBUs with a concentration of CD34+  > 2 × 10⁶, while no CBUs with high concentration of CD34+ were detect in group B.

Conclusion

This study, conducted on a very large series of CBUs without any specific volume constraint, highlighted the prenatal and maternal factors that significantly influence the quality of the CBU collected. Specifically, it highlights that volume is not the best predictor of CD34+ CBU content; for this reason it cannot be taken into consideration alone for the analysis of the collected samples. Our final aim is to identify relevant factors, immediately available, that help to choice UCB with high CD34+ cell content, especially in simultaneous deliveries.

Recent advances in hematopoietic cell transplantation for inherited bone marrow failure syndromes

Inherited bone marrow failure syndromes (IBMFSs) are a group of rare genetic disorders characterized by bone marrow failure with unique phenotypes and predisposition to cancer. Classical IBMFSs primarily include Fanconi anemia with impaired DNA damage repair, dyskeratosis congenita with telomere maintenance dysfunction, and Diamond-Blackfan anemia with aberrant ribosomal protein biosynthesis. Recently, comprehensive genetic analyses have been implemented for the definitive diagnosis of classic IBMFSs, and advances in molecular genetics have led to the identification of novel disorders such as AMeD and MIRAGE syndromes. Allogeneic hematopoietic cell transplantation (HCT), a promising option to overcome impaired hematopoiesis in patients with IBMFSs, does not correct nonhematological defects and may enhance the risk of secondary malignancies. Disease-specific management is necessary because IBMFSs differ in underlying defects and are associated with varying degrees of risk for clonal evolution and early or late complications after HCT. In addition, long-term follow-up is essential to detect complications related to the IBMFS or HCT. This review provides a summary of current clinical practices along with the latest data on HCT in IBMFSs.

Plumping up a Cushion of Human Biowaste in Regenerative Medicine: Novel Insights into a State-of-the-Art Reserve Arsenal

Major breakthroughs and disruptive methods in disease treatment today owe their thanks to our inch by inch developing conception of the infinitive aspects of medicine since the very beginning, among which, the role of the regenerative medicine can on no account be denied, a branch of medicine dedicated to either repairing or replacing the injured or diseased cells, organs, and tissues. A novel means to accomplish such a quest is what is being called “medical biowaste”, a large assortment of biological samples produced during a surgery session or as a result of physiological conditions and biological activities. The current paper accentuating several of a number of promising sources of biowaste together with their plausible applications in routine clinical practices and the confronting challenges aims at inspiring research on the existing gap between clinical and basic science to further extend our knowledge and understanding concerning the potential applications of medical biowaste.