Quality rather than quantity: the cord blood bank dilemma

Umbilical cord blood transplants facilitated by the French cord blood banks network. On behalf of the Agency of Biomedicine, Eurocord and the French society of bone marrow transplant and cell therapy (SFGM-TC)

The public French Cord Blood Banks Network was established in 1999 with the objective of standardizing the practices governing umbilical cord blood (UCB) banking in France. The Network adopted a strategy to optimize its inventory and improve the quality of its banked units based on a quality improvement process using outcome data regularly provided by Eurocord. This study aimed to describe the results, over 10 years, of UCBT facilitated by a national network that used the same criteria of UCB collection and banking and to assess how modifications of banking criteria and unit selection might influence transplant outcomes. Nine hundred and ninety-nine units (593 single-unit and 203 double-unit grafts) were released by the Network to transplant 796 patients with malignant (83%) and non-malignant (17%) diseases. Median cell dose exceeded 3.5 × 107 TNC/kg in 86%. There was a trend to select units more recently collected and with higher cell dose. Neutrophil engraftment was 88.2% (85.7-90.7) and 79.3% (72.6-86.5) respectively for malignant and non-malignant diseases with a trend to faster recovery with higher cell doses. The respective 3-year transplant-related mortality were 31.1% (27.5-35.1) and 34.3% (27.0-43.5). OS was 49% ± 4 in malignant and 62% ± 4 in non-malignant disorders. In multivariate analysis, cell dose was the only unit-related factor associated with outcomes. Our results reflect the benefit on clinical outcomes of the strategy adopted by the Network to bank units with higher cell counts.

The wider perspective: cord blood banks and their future prospects

Over the past three decades, cord blood transplantation (CBT) has established its role as an alternative allograft stem cell source. But the future of stored CB units should be to extend their use in updated transplant approaches and develop new CB applications. Thus, CBT will require a coordinated, multicentric, review of transplantation methods and an upgrade and realignment of banking resources and operations. Significant improvements have already been proposed to support the clinical perspective including definition of the cellular threshold for engraftment, development of transplantation methods for adult patients, engraftment acceleration with single cell expansion and homing technologies, personalised protocols to improve efficacy, use of adoptive cell therapy to mitigate delayed immune reconstitution, and further enhancement of the graft-versus-leukaemia effect using advanced therapies. The role of CB banks in improving transplantation results are also critical by optimizing the collection, processing, storage and characterization of CB units, and improving reproducibility, efficiency and cost of banking. But future developments beyond transplantation are needed. This implies the extension from transplantation banks to banks that support cell therapy, regenerative medicine and specialized transfusion medicine. This new "CB banking 2.0" concept will require promotion of international scientific and technical collaborations between bank specialists, clinical investigators and transplant physicians.

BSHI guideline: HLA matching and donor selection for haematopoietic progenitor cell transplantation

A review of the British Society for Histocompatibility and Immunogenetics (BSHI) Guideline 'HLA matching and donor selection for haematopoietic progenitor cell transplantation' published in 2016 was undertaken by a BSHI appointed writing committee. Literature searches were performed and the data extracted were presented as recommendations according to the GRADE nomenclature.

Cord blood beyond transplantation: can we use the experience to advance all cell therapies?

Unrelated cord blood (CB) units, already manufactured, fully tested and stored, are high-quality products for haematopoietic stem cell transplantation and cell therapies, as well as an optimal starting material for cell expansion, cell engineering or cell re-programming technologies. CB banks have been pioneers in the development and implementation of Current Good Manufacturing Practices for cell-therapy products. Sharing their technological and regulatory experience will help advance all cell therapies, CB-derived or not, particularly as they transition from autologous, individually manufactured products to stored, 'off-the shelf' treatments. Such strategies will allow broader patient access and wide product utilisation.

Current and Future Perspectives for the Cryopreservation of Cord Blood Stem Cells

Hematopoietic stem cell (HSC) transplantation is a well-established procedure for the treatment of many blood related malignancies and disorders. Before transplantation, HSC are collected and cryopreserved until use. The method of cryopreservation should preserve both the number and function of HSC and downstream progenitors responsible for long- and short-term engraftment, respectively. This is especially critical for cord blood grafts, since the cell number associated with this stem cell source is often limiting. Loss of function in cryopreserved cells occurs following cryoinjuries due to osmotic shock, dehydration, solution effects and mechanical damage from ice recrystallization during freezing and thawing. However, cryoinjuries can be reduced by 2 mitigation strategies; the use of cryoprotectants (CPAs) and use of control rate cooling. Currently, slow cooling is the most common method used for the cryopreservation of HSC graft. Moreover, dimethyl-sulfoxide (DMSO) and dextran are popular intracellular and extracellular CPAs used for HSC grafts, respectively. Yet, DMSO is toxic to cells and can cause significant side effects in stem cells' recipients. However, new CPAs and strategies are emerging that may soon replace DMSO. The aim of this review is to summarise key concepts in cryobiology and recent advances in the field of HSC cryobiology. Other important issues that need to be considered are also discussed such as transient warming events and thawing of HSC grafts.

High Integrity and Fidelity of Long-Term Cryopreserved Umbilical Cord Blood for Transplantation

Umbilical cord blood (UCB) is used as a source of donor cells for hematopoietic stem cell (HSC) transplantation. The success of transplantation is dependent on the quality of cord blood (CB) units for maximizing the chance of engraftment. Improved outcomes following transplantation are associated with certain factors of cryopreserved CB units: total volume and total nucleated cell (TNC) count, mononuclear cell (MNC) count, and CD34+ cell count. The role of the storage period of CB units in determining the viability and counts of cells is less clear and is related to the quality of cryopreserved CB units. Herein, we demonstrate the recovery of viable TNCs and CD34+ cells, as well as the MNC viability in 20-year-old cryopreserved CB units in a CB bank (MEDIPOST Co., Ltd., Seongnam-si, Gyeonggi-do, Korea). In addition, cell populations in CB units were evaluated for future clinical applications. The stable recovery rate of the viability of cryopreserved CB that had been stored for up to 20 years suggested the possibility of uses of the long-term cryopreservation of CB units. Similar relationships were observed in the recovery of TNCs and CD34+ cells in units of cryopreserved and fresh CB. The high-viability recovery of long-term cryopreserved CB suggests that successful hematopoietic stem cell (HSC) transplantation and other clinical applications, which are suitable for treating incurable diseases, may be performed regardless of long-term storage.

Prenatal selection of cord blood donors according to the estimated fetal weight percentile and new approaches; results of a prospective cohort study

BACKGROUND

Umbilical cord blood (UCB) donation is becoming inefficient and we recently proposed the estimated fetal weight percentile (EFWp) ≥60th as a predictor for a prenatal selection of donors. The aim of this study is to prospectively validate this and to identify new potential prenatal predictive parameters.

STUDY DESIGN AND METHODS

Prospective cohort study of low-risk pregnancies undergoing third trimester ultrasound, whose UCB was collected at delivery (2016-2018) and compared with a historical cohort (2013-2016, N = 869). Several ultrasound parameters (EFWp, amniotic fluid, Doppler evaluation, placental thickness) were assessed ultrasound and perinatal data were collected. The association with standard of high quality of UCB was assessed by logistic regression analysis.

RESULTS

Among 297 cases, 161 (54%) were selected according to the EFWp ≥60th for UCB units' collection. Cellular criteria for banking was achieved in 27 cases (16.8%), with an average increase of 1.7 times compared to the historical cohort (9.8%, P = .009). Selecting donors according to the 60th EFWp resulted in a higher probability of collecting clinical suitable UCB (P = .025). Among prenatal and perinatal parameters, EFWp, amniotic fluid, umbilical vein (UV) velocity, newborn weight and percentile and placental weight were significantly associated with a higher cellular content. At logistic regression analysis, significant contributors of UCB collection, were EFWp at 37-38 weeks ultrasound (OR 1.04; 95% CI: 1-1.08; P = .042) and UV velocity (OR 1.14; 95% CI: 1-1.29; P = .037).

CONCLUSION

The evaluation of the EFWp equal or above 60 and the increased UV velocity can result in higher efficiency of public UCB donation programs.

Enumerating regulatory T cells in cryopreserved umbilical cord blood samples using FOXP3 methylation specific quantitative PCR

BACKGROUND

Allogeneic haematopoietic cell transplantation (HCT) is a curative therapy for severe haematological disorders. However, it carries significant risk of morbidity and mortality. To improve patient outcomes, better graft selection strategies are needed, incorporating HLA matching with clinically important graft characteristics. Studies have shown that the cellular content of HCT grafts, specifically higher ratios of T regulatory (Tregs)/T cells, are important factors influencing outcomes when using adult peripheral blood mobilised grafts. So far, no equivalent study exists in umbilical cord blood (CB) transplantation due to the limitations of cryopreserved CB samples.

STUDY DESIGN AND METHODS

To establish the most robust and efficient way to measure the Treg content of previously cryopreserved CB units, we compared the enumeration of Treg and CD3+ cells using flow cytometry and an epigenetic, DNA-based methodology. The two methods were assessed for their agreement, consistency and susceptibility to error when enumerating Treg and CD3+ cell numbers in both fresh and cryopreserved CB samples.

RESULTS

Epigenetic enumeration gave consistent and comparable results in both fresh and frozen CB samples. By contrast, assessment of Tregs and CD3+ cells by flow cytometry was only possible in fresh samples due to significant cell death following cryopreservation and thawing.

CONCLUSION

Epigenetic assessment offers significant advantages over flow cytometry for analysing cryopreserved CB; similar cell numbers were observed both in fresh and frozen samples. Furthermore, multiple epigenetic assessments can be performed from DNA extracted from small cryopreserved CB segments; often the only CB sample available for clinical studies.

Values in tension. Clinical quality and civic participation in umbilical cord blood banking in Italy

In the dominant narrative of bioethics and biomedical discourse on public Umbilical Cord Blood (UCB) banking, the ethical value of donating UCB is unproblematically associated with the clinical quality of collected UCB. This article shows that this view is analytically untenable as it overlooks tensions and conflicts between the social values of donation and the clinical value of banked UCB in concrete arrangements regarding the logistics of UCB donation and collection. Adopting the notion of registers of valuing (Heuts and Mol 2013: Valuation Studies, 1, 2, 125-46) and analysing the case of the Italian network of public UCB banks and collection sites, this article shows how conflicting registers of valuing concerning UCB can shape different organisational models of UCB donation and collection, in which social values and clinical value are not unproblematically conflated. The article aims to demonstrate that the functioning of biobanking arrangements is dependent on how different values are accomplished and aligned in concrete practices of tissue donation and collection.

Noninvasive white blood cell quantification in umbilical cord blood collection bags with quantitative oblique back-illumination microscopy

BACKGROUND

Umbilical cord blood has become an important source of hematopoietic stem and progenitor cells for therapeutic applications. However, cord blood banking (CBB) grapples with issues related to economic viability, partially due to high discard rates of cord blood units (CBUs) that lack sufficient total nucleated cells for storage or therapeutic use. Currently, there are no methods available to assess the likelihood of CBUs meeting storage criteria noninvasively at the collection site, which would improve CBB efficiency and economic viability.

MATERIALS AND METHODS

To overcome this limitation, we apply a novel label-free optical imaging method, called quantitative oblique back-illumination microscopy (qOBM), which yields tomographic phase and absorption contrast to image blood inside collection bags. An automated segmentation algorithm was developed to count white blood cells and red blood cells (RBCs) and assess hematocrit. Fifteen CBUs were measured.

RESULTS

qOBM clearly differentiates between RBCs and nucleated cells. The cell-counting analysis shows an average error of 13% compared to hematology analysis, with a near-perfect, one-to-one relationship (slope = 0.94) and strong correlation coefficient (r = 0.86). Preliminary results to assess hematocrit also show excellent agreement with expected values. Acquisition times to image a statistically significant number of cells per CBU were approximately 1 minute.

CONCLUSION

qOBM exhibits robust performance for quantifying blood inside collection bags. Because the approach is automated and fast, it can potentially quantify CBUs within minutes of collection, without breaching the CBUs' sterile environment. qOBM can reduce costs in CBB by avoiding processing expenses of CBUs that ultimately do not meet storage criteria.

Recovery and Post-Thaw Assessment of Human Umbilical Cord Blood Cryopreserved as Quality Control Segments and Bulk Samples

Quality control (QC) segments conjoined to a bulk sample container are used to evaluate the viability and quality of cryopreserved umbilical cord blood (UCB). Such QC segments are typically attached lengths of sealed tubing that are cooled concurrently with the bulk sample, both containing material from the same donor. QC segments are thawed independently of the bulk sample to assess the quality of the cryopreserved product. In current practice, there is typically post-thaw variation between the QC segment and the bulk sample which if suggestive of inadequate performance, could lead to material being needlessly discarded. In this study, these performance differences were quantified. Two cooling protocols in common use, 1 with and 1 without a "plunge" step to induce ice nucleation, gave equivalent results that maintained the QC segment versus bulk sample differences. Ice nucleated at significantly lower temperatures in the QC segments compared with the bulk samples, a consequence of their lower volume, thereby enhancing damaging osmotic stress. A reduction in total viable cells of approximately 10% was recorded in the QC segments compared with comparable bulk samples. It has been shown that CD45⁺ cells are more adversely impacted by this lower ice nucleation temperature than CD34⁺ cells, which can result in altered composition of the post-thaw cell population.

A hands-on resident umbilical cord blood educational curriculum compared to online education of post-residency obstetricians: comparison of the volume of collected cord blood units

BACKGROUND

Umbilical cord blood unit (CBU) volume is a predictor of its later clinical utility. Many studies suggest the need to increase the volume of CBU collected, but most obstetrical providers receive no formal collection training.

STUDY DESIGN AND METHODS

We designed and implemented an educational curriculum for obstetrics residents aimed at improving collection methods and increasing CBU volumes (CBUV). Residents were required to attend grand rounds and interactive didactic sessions on CBU collection followed by work with a simulated collection kit and then performed training collections under observation by a trained collector. Residents completed a self-assessment after each collection and received immediate personal feedback. Outside providers (non-UAMS physicians) received written instructional materials with the collection kits and had access to online training materials. They received feedback regarding their collection via standard mail. CBU donated to Cord Blood Bank of Arkansas for public use from 2014-2016 were analyzed. CBUV from residents were compared to those from outside providers.

RESULTS

After adjusting for maternal age and race, infant gender, gestational age, and birth weight, the least-squared mean CBUV was 92.1 mL for UAMS collections and 65.5 mL for outside provider collections. The improved CBUV of UAMS providers is statistically significant (p < 0.0001).

CONCLUSION

Our educational intervention was successful, and we believe that it can be replicated in other obstetrical residency programs. Cord blood collection education involving hands-on training with a model and immediate feedback improves CBUV, decreases kit waste, increases likelihood of CBU storage, and, therefore, inventory for transplantation.

An objective flow cytometry method to rapidly determine cord blood potency in cryopreserved units

BACKGROUND

Cord blood banks have to determine the regenerative potential of cord blood units (CBUs) on a representative sample of the cryopreserved product before release to the transplant center. Potency can be measured by using a colony-forming unit (CFU) method, which delays the release of CBU by 7 to 14 days. To accelerate CBU qualification, we have developed a rapid method to assess the response of CD34 cells to interleukin (IL)-3. Flow cytometry was used to measure IL-3-induced STAT5 phosphorylation within CD34-cells. This IL-3 test was compared to the CFU method, as well as the aldehyde dehydrogenase (ALDH) enzyme-based assay.

STUDY DESIGN AND METHODS

Ten cryopreserved CBUs were analyzed for their contents in CD34 and CD45 viable cells, total CFUs, ADLHbright cells, and IL-3-responsive CD34+ cells. Extreme and mild warming event scenarios were simulated on CBUs and used as poor-quality samples. Segments, tubes, and bags from five CBUs were compared for their potency using IL-3 and CFU methods.

RESULTS

The IL-3 test was accurate in identifying the samples handled following standard operating procedures and those subjected to extreme warming events. Based on these results, a threshold of 55% of IL-3-responsive CD34 cells was established to identify good-quality samples. The IL-3 test was also the most sensitive to detect samples subjected to milder warming events.

CONCLUSIONS

Our new method for determining CBU functionality is rapid, unbiased, and robust. The IL-3 test described herein fulfills the requirements for validation, and we intend to implement this method in our cord blood bank facility.

Comparison and correlation among in vitro and in vivo assays to assess cord blood quality according to delivery temperature and time after collection

Cord blood (CB) has been used as an alternative source for unrelated allogeneic hematopoietic stem cell transplantation. To determine which assay was useful for predicting the successful outcome of CB transplantation, CBs were grouped according to the temperature (4 °C, 24 °C, and 37 °C) and time (24, 48, and 72 h) after collection. The viability, early apoptosis, and colony forming units (CFUs) were ascertained for the total nucleated cells (TNCs) and CD34+ cells; in addition, the engraftment of infused CD34+ cells in NSG mice was determined. The viability of the TNCs and CD34+ cells and total CFUs were significantly decreased whereas the early apoptosis was significantly increased in the 72 h group at 37 °C compared to that of the 24 h group at 24 °C. The viability and early apoptosis of the TNCs correlated with those of CD34+ cells. In addition, the viability and early apoptosis correlated with the number of granulocyte/monocyte progenitor CFUs. In transplanted NSG mice, the frequency of human CD45+ cells decreased in the 72 h group at 24 °C compared to that of the 24 h group at 24 °C and was negatively correlated with early apoptosis of TNCs and CD34+ cells. This study demonstrated that the early apoptosis of TNCs and CD34+ cells constitutes a useful marker for predicting the engraftment of HSCs and may provide helpful data for standard assessment regarding CB quality by analyzing the correlation between in vitro and in vivo assays using NSG mice.

Thawing methods do not affect cell viability of CD45+ and CD34+ cells, but long-term cryopreservation of umbilical cord blood units generally decreases cell viability

INTRODUCTION

Umbilical cord blood units (UCBUs) are collected and cryopreserved in biobanks for a future transplant. Hematopoietic stem cells and hematopoietic progenitor cells (HSC/HPC) present in UCB can be damaged due to factors such as the cryopreservation process, the thawing process, and prolonged storage time.

METHODS

UCBUs (n = 27) were obtained from the Biobank of the National Center of Blood Transfusion (NCBT) from Mexico. They contained three attached segments of UCBU, including 1.0-2.3 × 10⁶ CD34+ cells prior to cryopreservation and were stored during the period from 2003 to 2015. Each UCB segment was thawed with three different methods and CD34 cells, CD45 cells, and 7-AAD were identified by flow cytometry. Furthermore, we carried out CFU assays, and trypan blue staining.

RESULTS

Viable CD45+ (vCD45+) cells, vCD34+ cells, CFU, and percentage of E-Clone were not statistically significant among three different thawing methods. The number of vCD45+ and vCD34+ cells diminished in the three thawing methods compared with the same cells prior to their cryopreservation (p < 0.0001). vCD45+ and vCD34+ cells diminished in the ≥10-year cryopreservation group (p < 0.001). In addition, percentage of recovery of vCD45+ and vCD34+ cells diminished in this same group (p =  0.013 and p < 0.0001, respectively).

CONCLUSION

The thawing methods did not affect either cell viability (vCD45+ and vCD34+ cells) or pluripotency (CFU, percentage of E-Clone) in attached segments of UCBUs. The ≥10-year cryopreservation time in attached segments of UCBUs alters the number of vCD45+ and vCD34+ cells; however, it does not affect their pluripotency.

Estimated fetal weight percentile as a tool to predict collection of cord blood units with higher cellular content: implications for prenatal selection of cord blood donors

BACKGROUND

The need for high-cellular-content cord blood units (CBUs) for allogenic transplantation is evident to improve clinical outcomes. In our environment and with current donation programs, very few collected units meet suggested clinical thresholds, making collection programs highly inefficient. To increase the clinical conversion rate, we have assessed factors influencing the cellular content of the cord blood collection and established the estimated fetal weight percentile (EFWp) as a tool to predict which deliveries will obtain higher cellular counts.

STUDY DESIGN AND METHODS

We conducted a retrospective analysis of 11,349 collected CBUs. An analysis of diagnostic efficiency (receiver operating characteristic [ROC] curve) was performed to establish the cutoffs of several obstetric and perinatal variables from which we would obtain more than 1500 × 106 total nucleated cells and 4 × 106 CD34 cells. We then calculated the optimal EFWp cutoff to increase efficiency.

RESULTS

In the univariate analysis, factors positively and significantly associated were a greater neonatal and placental weight and longer weeks of gestation. In the multivariate analysis only neonatal and placental weight remain significant (p < 0.001). The ROC curve analysis showed that the optimal EFWp cutoff is 60, which has the maximum area under the curve. Applying this, donations meeting clinical cellular numbers will increase more than 30% with respect to not using any threshold.

CONCLUSION

The EFWp predicts the quality of the collected CBUs and can be used to make a prenatal selection of the donors, therefore increasing the efficiency of umbilical cord blood collection programs.

The aldehyde dehydrogenase cord blood potency assay excludes early apoptotic cells

BACKGROUND

Cord blood units (CBUs) are processed, frozen, and thawed before use in hematopoietic stem cell (HSC) transplantation. The manipulations affect HSC functionality, that is, induce apoptosis and reduce viability. HSC content, commonly expressed as CBU potency, that is, the expected ability of a CBU to restore hematopoiesis, is traditionally approximated through viable CD34+ cells and the colony-forming unit (CFU) cell cultivation assay. Alternative approaches, for example, the aldehyde dehydrogenase (ALDH) enzyme-based assay, are also forthcoming. We hypothesized that the ALDH assay might exclude apoptotic cells since it is based on enzyme activity. To investigate this, we designed a protocol for simultaneous staining of viable and apoptotic CD34+ and ALDH+ cells using 7-aminoactinomycin (7-AAD) and annexin V, in frozen-thawed CBUs. Results were correlated with results from the colony-forming unit-granulocyte/macrophage (CFU-GM) assay.

STUDY DESIGN AND METHODS

Samples from 57 CBUs were thawed and simultaneously analyzed for CD34+ cells, ALDH+ cells, viability (7-AAD), and apoptosis (annexin V) using flow cytometry. Enumeration of CFUs was also performed.

RESULTS

No nonviable and few apoptotic cells (mean 0.7%) were identified in the ALDH+ population compared to the viable CD34+ population (mean 3.6%). The total number of ALDH+ cells correlated better than viable CD34+ cells (r = 0. 72 vs. r = 0.66; p < 0.0001) with the results of the CFU assay.

CONCLUSION

The ALDH assay excludes nonviable and apoptotic cells, and therefore correlates better with CFU enumeration compared to the number of viable CD34+ cells. We propose that the ALDH assay might replace the CFU-GM method in CBU potency measurements.

Effects of Cryopreservation Duration on the Outcome of Single-Unit Cord Blood Transplantation

Cryopreservation is widely used in umbilical cord blood (UCB) banking, yet its impact on progenitor cell function remains largely unaddressed. It is unknown whether long-term cryopreservation affects UCB transplantation outcomes. Herein, we evaluated the impact of UCB age on clinical outcomes and investigated the effect of cryopreservation duration of UCB on hematopoietic potency in 91 patients receiving single cord blood transplantations. UCB cryopreservation duration was 0.7 to 13.4 y. The most common indication of transplant was thalassemia (48%). There was no significant association between cryopreservation duration and neutrophil engraftment probability (P = 0.475). Cryopreservation duration did not affect the post-thaw viability and subsequent neutrophil engraftment rate. Therefore, UCB units can undergo cryopreservation for at least 8 y with no impact on clinical outcomes.

Concentration of the CDCP1 protein in human cord plasma may serve as a predictor of hematopoietic stem and progenitor cell content

Successful hematopoietic stem and progenitor cell (HSPC) transplantation rests upon reliable methods for their enumeration in sources such as cord blood (CB). Methods used today are costly, time consuming and exhaust the limited number of cells needed for transplantation. The aim of this study was to analyze if surplus plasma from CB contains biomarkers that can predict HSPC content in CB. Frozen, surplus plasma from 95 CB units was divided into two groups based on CD34+ cell concentration. Birth weight, gestation age, gender, mode of delivery, collection volume, nucleated cell count and colony forming unit assay results were available. Samples were analyzed with a proximity ligation assay covering 92 different proteins. Two-group t-test with p-values adjusted for false discovery rate (FDR) identified 5 proteins that significantly differed between the two groups. CDCP1 was the most significant (FDR adjusted p-value 0.006). Correlation with CDCP1 concentration was most significant for CD34+ concentration and nucleated cell count. Multivariate analysis showed that CD34 and gender seemed to influence the level of CDCP1. In conclusion, CDCP1 was identified as a potential biomarker of HSPC content in CB. The finding also warrants further investigation for a possible role of CDCP1 in regulating HSPC presence in CB.

Clinical Grade Regulatory CD4+ T Cells (Tregs): Moving Toward Cellular-Based Immunomodulatory Therapies

Regulatory T cells (Tregs) are CD4⁺ T cells that are key players of immune tolerance. They are powerful suppressor cells, able to impact the function of numerous immune cells, including key effectors of inflammation such as effector T cells. For this reason, Tregs are an ideal candidate for the development of cell therapy approaches to modulate immune responses. Treg therapy has shown promising results so far, providing key knowledge on the conditions in which these cells can provide protection and demonstrating that they could be an alternative to current pharmacological immunosuppressive therapies. However, a more comprehensive understanding of their characteristics, isolation, activation, and expansion is needed to be able design cost effective therapies. Here, we review the practicalities of making Tregs a viable cell therapy, in particular, discussing the challenges faced in isolating and manufacturing Tregs and defining what are the most appropriate applications for this new therapy.

Italian Recommendations for Placental Transfusion Strategies

At delivery, if the cord is not clamped, blood continues to pass from the placenta to the newborn during the first minutes of life, allowing the transfer of 25-35 ml/kg of placental blood to the newborn, depending on gestational age, the timing of cord clamping, the position of the infant at birth, the onset of respiration, and administration of uterotonics to the mother. However, deriving benefits from delayed cord clamping (DCC) are not merely related to placental-to-fetal blood transfusion; establishing spontaneous ventilation before cutting the cord improves venous return to the right heart and pulmonary blood flow, protecting the newborn from the transient low cardiac output, and systemic arterial pressure fluctuations. Recent meta-analyses showed that delayed cord clamping reduces mortality and red blood cell transfusions in preterm newborns and increases iron stores in term newborns. Various authors suggested umbilical cord milking (UCM) as a safe alternative when delayed cord clamping is not feasible. Many scientific societies recommend waiting 30-60 s before clamping the cord for both term and preterm newborns not requiring resuscitation. To improve the uptake of placental transfusion strategies, in 2016 an Italian Task Force for the Management of Umbilical Cord Clamping drafted national recommendations for the management of cord clamping in term and preterm deliveries. The task force performed a detailed review of the literature using the GRADE methodological approach. The document analyzed all clinical scenarios that operators could deal with in the delivery room, including cord blood gas analysis during delayed cord clamping and time to cord clamping in the case of umbilical cord blood banking. The panel intended to promote a more physiological and individualized approach to cord clamping, specifically for the most preterm newborn. A feasible option to implement delayed cord clamping in very preterm deliveries is to move the neonatologist to the mother's bedside to assess the newborn's clinical condition at birth. This option could safely guarantee the first steps of stabilization before clamping the cord and allow DCC in the first 30 s of life, without delaying resuscitation. Contra-indications to placental transfusion strategies are clinical situations that may endanger mother 's health and those that may delay immediate newborn's resuscitation when required.

Comparison of human umbilical cord blood processing with or without hydroxyethyl starch

BACKGROUND

Umbilical cord blood (UCB) processing with hydroxyethyl starch (HES) is the most common protocol in the cord blood banks. The quality of UCB volume reduction was guaranteed by minimum manipulation of cord blood samples in the closed system. This study aimed to analyze and compare cell recovery and viability of UCB processed using the Sepax automated system in the presence and absence of HES.

STUDY DESIGN AND METHODS

Thirty UCB bags with a total nucleated cell (TNC) count of more than 2.5 × 109 were divided in two bags with equal volume. HES solution was added to one bag and another was intact. Both bags were processed with the Sepax. To determine cell recovery, viability, and potential of colony-forming cells (CFCs), preprocessing, postprocessing, and thawing samples were analyzed.

RESULTS

The mean TNC recovery after processing and after thaw was significantly better with the HES method (p < 0.01 for the postprocessing step and p < 0.05 for the postthaw step). There were no significant differences to mononucleated cells (MNCs) and CD34+ cell recovery between the two methods after processing and after thaw. TNC and MNC viability was significantly higher without HES after processing and after thaw (p < 0.01). The results of the CFC assay were similar for both methods after processing and after thaw.

CONCLUSION

These results showed that processing of UCB using the Sepax system with the without-HES protocol due to the lower manipulation of samples could be used as an eligible protocol to reduce the volume of UCB.

A new strategy for umbilical cord blood collection developed at the first Colombian public cord blood bank increases total nucleated cell content

BACKGROUND

The total nucleated cell dosage of umbilical cord blood (UCB) is an important factor in determining successful allogeneic hematopoietic stem cell transplantation after a minimum human leukocyte antigen donor-recipient match. The northern South American population is in need of a new-generation cord blood bank that cryopreserves only units with high total nucleated cell content, thereby increasing the likelihood of use. Colombia set up a public cord blood bank in 2014; and, as a result of its research for improving high total nucleated cell content, a new strategy for UCB collection was developed.

STUDY DESIGN AND METHODS

Data from 2933 collected and 759 cryopreserved cord blood units between 2014 and 2015 were analyzed. The correlation of donor and collection variables with cellularity was evaluated. Moreover, blood volume, cell content, CD34+ count, clonogenic capacity, and microbial contamination were assessed comparing the new method, which combines in utero and ex utero techniques, with the conventional strategies.

RESULTS

Multivariate analysis confirmed a correlation between neonatal birth weight and cell content. The new collection method increased total nucleated cell content in approximately 26% and did not alter pre-cryopreservation and post-thaw cell recovery, viability, or clonogenic ability. Furthermore, it showed a remarkably low microbial contamination rate (1.2%).

CONCLUSION

The strategy for UCB collection developed at the first Colombian public cord blood bank increases total nucleated cell content and does not affect unit quality. The existence of this bank is a remarkable breakthrough for Latin-American patients in need of this kind of transplantation.

The role of policies and networks in development of cord blood usage in China

Research regarding the use of cord blood (CB) has focused on antigen match and the number of stem cells, with policies and networks related to its use being under researched. This article is based on fieldwork in China from 2013 to 2015 and examines ways that the studied CB bank enhances CB usage in China. This article identifies that in addition to finding a match, CB use is linked to the policies and networks, release fee and public awareness that enable CB usage development.

The influence of temperature treatment before cryopreservation on the viability and potency of cryopreserved and thawed CD34+ and CD45+ cord blood cells

BACKGROUND

Hematopoietic stem cell (HSC) viability and potency is crucial for qualified cord blood (CB) transplants. This study analyzes time and temperature condition before cryopreservation for the viability of CD34⁺/CD45⁺ cells after cryopreservation.

METHODS

Cell viabilities were determined by antibody co-staining with 7-aminoactinomycin D detecting necrotic cells, and subsequent flow cytometric analysis. Additionally, Annexin V staining for determination of apoptotic cells and colony-forming unit (CFU) assays for testing functional potency of HSCs were performed.

RESULTS

For all cell types assessed (CD45⁺/CD34⁺ cells, lymphocytes and granulocytes), the highest viabilities were obtained for CB maintained at 4°C or room temperature (RT; 22 ± 4°C) and cryopreserved directly after collection. Starting material were CB units with an age of 24.7 ± 3.5 h after birth. Post-thaw CD34⁺ cell results were > 90% after temperature treatment of t = 24 h (48 h total age) and > 70% after t = 48 h (72 h total age) at 4°C (48 h, 91.4 ± 5.5%; 72 h, 75.0 ± 12.0%) and RT (48 h, 84.2 ± 9.7%; 72 h, 72.6 ± 0.6%). Viabilities for 30°C samples were < 80% after t = 24 h (48 h total age, 79.8 ± 3.1%) and < 50% after t = 48 h of treatment (72 h total age, 46.8 ± 14.3%). Regarding CFU recovery of pre-freeze (without volume reduction) and thawed CB, a trend toward the highest recoveries was observed at 4°C/RT. The difference between 4°C (77.5 ± 12.0%) and 30°C samples (53.9 ± 4.8%) was shown to be significant in post-thaw samples after t = 24 h treatment (48 h total age; P = 0.0341).

DISCUSSION

Delays between collection and cryopreservation should be minimized because increasing time reduces numbers of viable cells and CFUs before/after cryopreservation. CB units should be maintained at 4°C/RT to retain the highest possible potency of the cells after thawing.

Predictors of high-quality cord blood units

BACKGROUND

Analysis of umbilical cord blood (UCB) transplants shows a correlation between engraftment and total number of infused cells. Thus, it is worth evaluating what maternal and neonatal characteristics and collection techniques may affect the quality of UCB units.

STUDY DESIGN AND METHODS

A cross-sectional study was performed with 7897 donors sequentially selected in three health care institutions in Brazil from October 2004 to March 2012, in which both quantitative and qualitative approaches were applied. All donors were considered suitable for cord blood collection.

RESULTS

The maternal and neonatal characteristics and techniques of collection that influenced the total number of nucleated cells (TNCs; p < 0.001) were type of delivery, newborn weight and sex, and institution of UCB collection. The TNC count was associated with gestational age (p = 0.008), type of delivery (p < 0.001), newborn sex (p < 0.001), newborn weight (p < 0.001), and UCB collection technique (p = 0.003). Center B presented the largest number of nucleated cells in its results (p < 0.001), followed by Center A (p = 0.001). Other characteristics, such as maternal age, were analyzed but were not relevant for the nucleated cell number.

CONCLUSION

This study provides elements for a model that allows an efficient selection of UCB donors, prioritizing candidates who have a better chance to lead to an optimized use of cord blood cells units.

High quality cord blood banking is feasible with delayed clamping practices. The eight-year experience and current status of the national Swedish Cord Blood Bank

The National Swedish Cord Blood Bank (NS-CBB) is altruistic and publicly funded. Herein we describe the status of the bank and the impact of delayed versus early clamping on cell number and volume. Cord Blood Units (CBUs) were collected at two University Hospitals in Sweden. Collected volume and nucleated cell content (TNC) were investigated in 146 consecutive Cord Blood (CB) collections sampled during the first quarter of 2012 and in 162 consecutive CB collections done in the first quarter of 2013, before and after clamping practices were changed from immediate to late (60 s) clamping. NS-CBB now holds close to 5000 units whereof 30 % are from non-Caucasian or mixed origins. Delayed clamping had no major effect on collection efficiency. The volume collected was slightly reduced (mean difference, 8.1 ml; 95 % CI, 1.3-15.0 ml; p = 0.02), while cell recovery was not (p = 0.1). The proportion of CBUs that met initial total TNC banking criteria was 60 % using a TNC threshold of 12.5 × 10(8), and 47 % using a threshold of 15 × 10(8) for the early clamping group and 52 and 37 % in the late clamping group. Following implementation of delayed clamping practices at NS-CBB; close to 40 % of the collections in the late clamping group still met the high TNC banking threshold and were eligible for banking, implicating that that cord blood banking is feasible with delayed clamping practices.

Cord blood collection and processing with hydroxyethyl starch or non-hydroxyethyl starch

BACKGROUND

Collection and processing characteristics influencing quality of cord blood (CB) units play an essential role to cord blood banks (CBBs). At many CBBs, volume reduction is performed using hydroxyethyl starch (HES) and the Sepax (Biosafe) automated cell processing system. Due to the withdrawal of HES from the European market, a validation of the nonHES protocol was performed.

METHODS

This partially retrospective study identified CB characteristics such as gestational age and CB volume/cell count correlated with higher quality. For the nonHES validation, CB was analyzed for total nucleated cell (TNC), mononuclear cell (MNC) recovery, hematocrit (HCT) and colony-forming units (CFUs). Viabilities of CD34(+) and CD45(+) cells were determined by 7-aminoactinomycin D (7-AAD) and AnnexinV (AnnV) staining and compared for 21 mL and 42 mL buffy coat (BC) samples applying the HES/nonHES protocol.

RESULTS

Factors affecting the potency of CB transplants were the gestational age and the volume reduction to a defined BC volume. High initial cell counts and CB volumes correlated negatively with post-processing TNC recovery for lower BC volumes. Post-processing HES and nonHES results were comparable, but nonHES revealed a significantly lower post-thaw recovery of viable CD34(+) cells measured by 7-AAD/AnnV (21 mL: 45.4 ± 16.4%; 42 mL: 67.3 ± 14.5%) as compared with HES (21 mL: 72.7 ± 14.4%, P = 0.0164; 42 mL: 83.4 ± 14.7%, P = 0.0203).

DISCUSSION

Due to the lower post-thaw CD34(+) cell viability (AnnV(-)/7-AAD(-)) for nonHES samples, the use of HES is recommended, ideally combined with a high BC volume. The post-processing HCT has no statistically significant impact on the post-thaw CD34(+) cell viability (AnnV(-)/7-AAD(-)).

Detecting primitive hematopoietic stem cells in total nucleated and mononuclear cell fractions from umbilical cord blood segments and units

BACKGROUND

Rare hematopoietic stem cell populations are responsible for the transplantation engraftment process. Umbilical cord blood (UCB) is usually processed to the total nucleated cell (TNC), but not to the mononuclear cell (MNC) fraction. TNC counts are used to determine UCB unit storage, release for transplantation and correlation with time to engraftment. However, the TNC fraction contains varying concentrations of red blood cells, granulocytes, platelets and other cells that dilute and mask the stem cells from being detected. This does not allow the quality and potency of the stem cells to be reliably measured.

METHODS

63 UCB segments and 10 UCB units plus segments were analyzed for the response of both primitive lympho-hematopoietic and primitive hematopoietic stem cells in both the TNC and MNC fractions. The samples were analyzed using a highly sensitive, standardized and validated adenosine triphosphate (ATP) bioluminescence stem cell proliferation assay verified against the colony-forming unit (CFU) assay. Dye exclusion and metabolic viability were also determined.

RESULTS

Regardless of whether the cells were derived from a segment or unit, the TNC fraction always produced a significantly lower and more variable stem cell response than that derived from the MNC fraction. Routine dye exclusion cell viability did not correspond with metabolic viability and stem cell response. Paired UCB segments produced highly variable results, and the UCB segment did not produce similar results to the unit.

DISCUSSION

The TNC fraction underestimates the ability and capacity of the stem cells in both the UCB segment and unit and therefore provides an erroneous interpretation of the of the results. Dye exclusion viability can result in false positive values, when in fact the stem cells may be dead or incapable of proliferation. The difference in response between the segment and unit calls into question the ability to use the segment as a representative sample of the UCB unit. It is apparent that present UCB processing and testing methods are inadequate to properly determine the quality and potency of the unit for release and use in a patient.

Exploring the heterogeneity of the hematopoietic stem and progenitor cell pool in cord blood: simultaneous staining for side population, aldehyde dehydrogenase activity, and CD34 expression

BACKGROUND

The stem cell content in cord blood (CB) units is routinely assessed regarding nucleated cells, CD34+ cell count, and number of colony-forming units (CFUs). Efforts are made toward finding better ways of defining stemness of CB units. Side population (SP) phenotype and activity of aldehyde dehydrogenase (ALDH) are functional markers of stemness that can be assayed using flow cytometry.

STUDY DESIGN AND METHODS

We have developed a protocol for simultaneous determination of CD34+, SP, and ALDH+ populations in relation to immature white blood cells (CD45dim) in CB. Viable nucleated cells were consecutively stained for SP and ALDH activity and with antibodies against the CD45, CD34, and CD117 antigens.

RESULTS

The SP and ALDH+ populations could reliably be measured simultaneously. The median sizes of the SP and the ALDH+ populations were 0.85 and 3.3% of CD45dim cells, respectively. There was no overlap between the SP and ALDH+ populations. Cells that were ALDH+ expressed CD34 and CD117, but SP cells were negative for these markers. The ALDH+ cell content correlated with CD34+ cell content (p < 0.001) and with CFU-granulocyte-macrophage (GM; p = 0.03) but not with total CFUs. SP did not correlate with CD34+, CFU-GM, or total CFU.

CONCLUSIONS

We show that simultaneous detection of the CD34, SP, and ALDH+ cells is clearly feasible using only small amounts of CB. In CB, ALDH+, and CD34+ cells are overlapping populations distinctly separated from the SP population. The difference in relation to the capacity for colony growth between ALDH+ and SP underlines that they define different cell populations.

Improving umbilical cord blood processing to increase total nucleated cell count yield and reduce cord input wastage by managing the consequences of input variation

BACKGROUND AIMS

With the rising use of umbilical cord blood (UCB) as an alternative source of hematopoietic stem cells, storage inventories of UCB have grown, giving rise to genetically diverse inventories globally. In the absence of reliable markers such as CD34 or counts of colony-forming units, total nucleated cell (TNC) counts are often used as an indicator of potency, and transplant centers worldwide often select units with the largest counts of TNC. As a result, cord blood banks are driven to increase the quality of stored inventories by increasing the TNC count of products stored. However, these banks face challenges in recovering consistent levels of TNC with the use of the standard protocols of automated umbilical cord processing systems, particularly in the presence of input variation both of cord blood volume and TNC count, in which it is currently not possible to process larger but useable UCB units with consequent losses in TNC.

METHODS

This report addresses the challenge of recovering consistently high TNC yields in volume reduction by proposing and validating an alternative protocol capable of processing a larger range of units more reliably.

RESULTS

This work demonstrates improvements in plastic ware and tubing sets and in the recovery process protocol with consequent productivity gains in TNC yield and a reduction in standard deviation.

CONCLUSIONS

This work could pave the way for cord blood banks to improve UCB processing and increase efficiency through higher yields and lower costs.

Few and nonsevere adverse infusion events using an automated method for diluting and washing before unrelated single cord blood transplantation

Graft dilution and DMSO washing before cord blood (CB) administration using an automated system may offer low incidence of adverse infusion events (AIE), ensuring reproducible cell yields. Hence, we analyzed the incidences and significance of immediate AIE, cellular yield, and engraftment after single CB infusion. One hundred and fifty-seven patients (median age, 20 years; range, 1 to 60) received a single CB unit for treatment of hematologic and nonhematologic malignancies with myeloablative conditioning after graft dilution and washing. The median total nucleated cell (TNC) doses was 3.4 × 10(7)/kg (range, 2 to 26) and the median post-thaw recovery was 84% (range, 45 to 178). The cumulative incidence of neutrophil engraftment at 50 days was 84% (95% confidence interval [CI], 83 to 93). A total of 118 immediate AIE were observed in fifty-two (33%) patients. All reported AIE were transient, graded from 1 to 2 by Common Terminology Adverse Events version 4. The most frequent toxicity was cardiovascular but without any life-threatening reaction. Infused TNC, recipient's weight, and rate of infusion per kilogram were risk factors associated with cardiovascular AIE in multivariate analysis (odds ratio [OR], 1.2 (95% CI, 1.1 to 1.4); P < .001; OR, .94 (95% CI, .9 to .97); P < .001; and OR, 1.5 (95% CI, 1.2 to 1.8); P < .001; respectively). In summary, use of an automated method for graft washing before CB administration showed low incidence of AIE without compromising cell yields and engraftment. Infused TNC dose, recipient's weight, and rate of infusion per kilogram were risk factors associated with infusion reactions.

Factors which can influence the quality related to cell viability of the umbilical cord blood units

Cell viability is an important indicator for the quality of umbilical cord blood (UCB) units that can influence the transplant final outcome. Thus, it is particularly important to identify the factors that may affect the cell quality during the banking process. The present study is a first attempt to correlate the impact of exogenous factors (time from collection to processing, collected UCB volume) and endogenous factors (TNCC--total nucleated cell count, CD34(+)cell count) on cell viability assessed before UCB units cryopreservation within a banking standardized process. Three thousand UCB units collected in 35 ml CPDA containing bags were processed by HES sedimentation within 48 h. TNCC, CD34(+) cell counts and total cell viability were determined after processing. Cell viability of 94.37 ± 4.67%, TNCC of 73.17 ± 36.73 × 10(7) and CD34(+)cell count of 2.61 ± 2.29 × 10(6) was obtained after processing of units with UCB collected volume of 80.23 ± 28.52 ml. A significant negative correlation was found between cell viability and the time from collection to processing (r = -0.7228; P < 0.0001). The cell viability decreasing rate of 20.54%, 15.18% and 3-10% were achieved for units with collected UCB volume <40 ml, (40-80 ml) and >80 ml, to 48 h versus 12 h. There were no differences considering cell viability for the UCB units with similar collected UCB volume that had various CD34(+)cell count or TNCC (P > 0.05). The extension of the time from collection to processing of UCB units can reduce the quality by decreasing cell viability. The cell viability decreasing rate owing to the time influence is determined by the collected UCB volume being inversely proportional to it. Endogenous factors do not affect the cell viability.

Umbilical cord blood CD34(+) stem cells and other mononuclear cell subtypes processed up to 96 h from collection and stored at room temperature maintain a satisfactory functionality for cell therapy

BACKGROUND AND OBJECTIVES

Umbilical cord blood (UCB) is a good stem cell source for cell therapy. We recently demonstrated that cord blood mononuclear cell (MNCs) subtypes were viable and functional until 96 h after collection, even stored at room temperature. Now, we analyzed the viability and functionality of the cells before and after cryopreservation.

MATERIALS AND METHODS

Twenty UCB units were analyzed at 24 and 96 h after collection, frozen for 6 months, thawed and re-evaluated. MNCs were analyzed by flow cytometry, viability by 7-AAD and clonogenic assays (CFU) were performed.

RESULTS

After 96 h of storage, no substantial loss of MNC was found (median 7.320 × 10(6 ) × 6.05 × 10(6) ). Percentage and viability CD34(+) cells, B-cell precursors and mesenchymal stem cells were not affected. However, mature B and T lymphocytes as well as granulocytes had a substantial loss. CFU growth was observed in all samples. Prefreezing storage of 96 h was associated with a relative loss of colony formation (median 12%). Postthaw, this loss had a median of 49% (24 h samples) to 56% (96 h samples).

CONCLUSION

The delay of 96 h before UCB processing is possible, without a prohibitive impairment of CD34(+) loss in number and functionality.

Comprehensive study of hydrostatic pressure treated human umbilical cord blood cells via response surface method

Amelioration of the survival parameters of cryopreserved samples after thawing has already been addressed through several techniques including vitrification to avoid the formation of ice cores. However, this approach cannot be followed in the case of samples with higher volumes. Hydrostatic pressure (HP) treatment has been proven to increase some qualifying parameters (e.g., motility, insemination efficiency) of certain biological samples. Accordingly, the preparation of umbilical cord blood (UCB) samples through an active (mechanical) pre-stressing process to increase the survival rate of cryopreserved samples can be regarded as a novel strategy that calls for basic experimental studies. The goal of our study was to assess the effects of HP treatment on the qualifying parameters (DNA fragmentation by agarose gel electrophoresis and capillary electrophoresis, Total Nucleotide Cell (TNC) count, CD34+/CD45+ count, and superoxide dismutase activity (SOD) of human umbilical cord blood (UCB) derived cells). The experimental arrangement was set to provide data for response-surface analysis to take into account the common effects of the individual variables of pressure and time exposure. 3D visualization of experimental data revealed that 50-min long HP treatment at 12.5 MPa can significantly (α = 0.05) enhance white blood cell (WBC) and CD34+/CD45+ cell counts. However no DNA fragmentation was observed even at higher pressures, SOD activity was triggered over 15.0 MPa. As a conclusion, HP treatment may contribute to the optimal cryopreservation of UCB cells by significantly increasing WBC and CD34+/CD45+ cell counts without adverse effects neither on DNA stability nor on triggering SOD activity.

Current thawing and infusion practice of cryopreserved cord blood: the impact on graft quality, recipient safety, and transplantation outcomes

Methods of handling, thawing, and infusion of cord blood (CB) products vary substantially among thaw/transplant centers (TCs). This review 1) compares currently available CB product types and thaw methods recommended by CB banks (CBBs), 2) discusses causes of inconsistency in thaw method application at TCs, 3) advises elements to consider in thaw method approval or selection at the TC, 4) provides a procedural template for the traditional thaw methods, and 5) suggests acceptable time from product thaw to infusion and other considerations for safe infusion. It also compares postinfusion adverse reaction and engraftment data as functions of thaw methods. Remarks and suggestions made throughout this review are: 1) not intended to supersede manufacturer's instructions but meant to support the standardization of preparative procedures recommended by CBBs and 2) intended to help TCs to investigate relevant quality issues and handle challenges, especially when the TC is unable to follow recommendations due to foreseeable technical, quality, and/or clinical factors.

Optimization of the viability of stem cells derived from umbilical cord blood after maternal supplementation with DHA during the second or third trimester of pregnancy: study protocol for a randomized controlled trial

BACKGROUND

Umbilical cord blood (UCB) is an important source of hematopoietic stem cells (HSCs). However, the concentration of cells in cord blood units is limited and this may represent the main restriction to their therapeutic clinical use. The percentage of metabolically active stem cells provides a measure of the viability of cells in an UCB sample. It follows that an active cellular metabolism causes a proliferation in stem cells, offering an opportunity to increase the cellular concentration. A high cell dose is essential when transplanting cord stem cells, guaranteeing, in the receiving patient, a successful outcome.This study is designed to evaluate the impact of docosahexaenoic acid (DHA) supplementation in pregnant women, in order to increase the quantity and viability of the cells in UCB samples.

METHODS/DESIGN

The metabolic demand of DHA increases in the course of pregnancy and reaches maximum absorption during the third trimester of pregnancy. According to these observations, this trial will be divided into two different experimental groups: in the first group, participants will be enrolled from the 20th week of estimated stage of gestation, before the maximum absorption of DHA; while in the second group, enrolment will start from the 28th week of estimated stage of gestation, when the DHA request is higher. Participants in the trial will be divided and randomly assigned to the placebo group or to the experimental group. Each participant will receive a complete set of capsules of either placebo (250 mg of olive oil) or DHA (250 mg), to take one a day from the 20th or from the 28th week, up to the 40th week of estimated gestational age. Samples of venous blood will be taken from all participants before taking placebo or DHA, at the 20th or at the 28th week, and at the 37th to 38th week of pregnancy to monitor the level of DHA. Cell number and cellular viability will be evaluated by flow cytometry within 48 hours of the UCB sample collection.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number Register: ISRCTN58396079. Registration date: 8 October 2013.

Ethical and legal issues raised by cord blood banking - the challenges of the new bioeconomy

• Cord blood banking raises ethical and legal issues which highlight the need for careful regulatory approaches to the emerging bioeconomy. • Consent processes for both private and public banking should be inclusive and representative of the different familial interests in the cord blood. • Property law is a potentially useful way of understanding the mechanisms for donation to both public and private banks. • Increasing tensions between public and private models of banking may require the adoption of hybrid forms of banking.

Qualitative and quantitative cell recovery in umbilical cord blood processed by two automated devices in routine cord blood banking: a comparative study

BACKGROUND

Volume reduction is a widely used procedure in umbilical cord blood banking. It concentrates progenitor cells by reducing plasma and red blood cells, thereby optimising the use of storage space. Sepax and AXP are automated systems specifically developed for umbilical cord blood processing. These systems basically consist of a bag processing set into which cord blood is transferred and a device that automatically separates the different components during centrifugation.

METHODS

The aim of this study was to analyse and compare cell recovery of umbilical cord blood units processed with Sepax and AXP at Valencia Cord Blood Bank. Cell counts were performed before and after volume reduction with AXP and Sepax.

RESULTS

When analysing all the data (n =1,000 for AXP and n= 670 for Sepax), the percentages of total nucleated cell recovery and red blood cell depletion were 76.76 ± 7.51% and 88.28 ± 5.62%, respectively, for AXP and 78.81 ± 7.25% and 88.32 ± 7.94%, respectively, for Sepax (P <0.005 for both variables). CD34(+) cell recovery and viability in umbilical cord blood units were similar with both devices. Mononuclear cell recovery was significantly higher when the Sepax system was used.

DISCUSSION

Both the Sepax and AXP automated systems achieve acceptable total nucleated cell recovery and good CD34(+) cell recovery after volume reduction of umbilical cord blood units and maintain cell viability. It should be noted that total nucleated cell recovery is significantly better with the Sepax system. Both systems deplete red blood cells efficiently, especially AXP which works without hydroxyethyl starch.

The Assessment of Parameters Affecting the Quality of Cord Blood by the Appliance of the Annexin V Staining Method and Correlation with CFU Assays

The assessment of nonviable haematopoietic cells by Annexin V staining method in flow cytometry has recently been published by Duggleby et al. Resulting in a better correlation with the observed colony formation in methylcellulose assays than the standard ISHAGE protocol, it presents a promising method to predict cord blood potency. Herein, we applied this method for examining the parameters during processing which potentially could affect cord blood viability. We could verify that the current standards regarding time and temperature are sufficient, since no significant difference was observed within 48 hours or in storage at 4°C up to 26°C. However, the addition of DMSO for cryopreservation alone leads to an inevitable increase in nonviable haematopoietic stem cells from initially 14.8% ± 4.3% to at least 30.6% ± 5.5%. Furthermore, CFU-assays with varied seeding density were performed in order to evaluate the applicability as a quantitative method. The results revealed that only in a narrow range reproducible clonogenic efficiency (ClonE) could be assessed, giving at least a semiquantitative estimation. We conclude that both Annexin V staining method and CFU-assays with defined seeding density are reliable means leading to a better prediction of the final potency. Especially Annexin V, due to its fast readout, is a practical tool for examining and optimising specific steps in processing, while CFU-assays add a functional confirmation.

A review of factors influencing the banking of collected umbilical cord blood units

Umbilical cord blood banking efforts have increased dramatically in the past two decades in response to increasing demand for alternative sources of blood stem cells to support patients requiring hematopoietic stem cell transplantation. Transplant centres have accumulated increasing expertise in their understanding of umbilical cord blood characteristics that are associated with improved outcome following transplantation. These characteristics and factors can assist transplant centres in selecting cord blood units from the worldwide inventory of banked units. Umbilical cord blood banks, therefore, need to remain agile in adjusting the inventory of the banks to address shifts or changes in the needs of transplant centres. Public umbilical cord blood banks face the challenge of building inventory while managing limited resources and are faced with decisions regarding which units can be stored and which units that have been collected should be discarded or used for other endeavours such as research. To this end, we sought to review parameters influencing the decision to bank a collected cord blood unit. In this paper, we will address parameters associated with graft potency and address other factors that guide the decision to bank collected units.

Viability of umbilical cord blood mononuclear cell subsets until 96 hours after collection

BACKGROUND

Umbilical cord blood (UCB) is a good source of hematopoietic stem cells for transplantation and cell therapy. In 2006, the Brazilian Public Network of Cord Blood Banks was founded; however, because our country is large, logistic problems could hamper the collection of numerous samples. Our aim was to evaluate the viability of several UCB cell subsets until 96 hours after collection, to examine whether this delay would be acceptable for processing and freezing the samples.

STUDY DESIGN AND METHODS

Two experiments were performed: in the first one, volume reduction of the UCB units was carried out before analysis. In the second one, analysis was carried out with no previous manipulation. Samples were stored at room temperature and one aliquot was taken daily for analysis. We examined CD34+ cell, B-cell precursor, mature B and T lymphocyte, monocyte, granulocyte, and mesenchymal stem cell (MSCs) concentrations.

RESULTS

Thirty-six UCB units were analyzed. CD34+ cells and mature T lymphocytes increased (viability 99%). Mature B lymphocytes and MSCs decreased, maintaining viability. Granulocytes decreased with loss of viability. Monocytes and immature B lymphocytes remained stable. Clonogenic assays showed a decrease in colony-forming unit (CFU) number in UCB units stored for 96 hours.

CONCLUSION

UCB manipulation did not influence cell viability. All cell subsets remained viable until 96 hours after collection. CD34+ cells and T lymphocytes increased, probably due to the loss of other subsets. CFU growth during the period analyzed and confirmed stem cell functionality, despite the decrease at 96 hours. Results demonstrated that UCB units could probably be processed up to 96 hours after collection.

The Role of HLA in Cord Blood Transplantation

In recent years, umbilical cord blood (CB), a rich source of hematopoietic stem cells (HSC), has been used successfully as an alternative HSC source to treat a variety of hematologic, immunologic, genetic, and oncologic disorders. CB has several advantages, including prompt availability of the transplant, decrease of graft versus host disease (GVHD) and better long-term immune recovery, resulting in a similar long-term survival. Studies have shown that some degree of HLA mismatches is acceptable. This review is intended to outline the main aspects of HLA matching in different settings (related, pediatric, adult, or double-unit HSCT), its effect on transplantation outcome and the role of HLA in donor selection.

Autologous stem cells for personalised medicine

Increasing understanding of stem cell biology, the ability to reprogramme differentiated cells to a pluripotent state and evidence of multipotency in certain adult somatic stem cells has opened the door to exciting therapeutic advances as well as a great deal of regulatory and ethical issues. Benefits will come from the possibility of modelling human diseases and develop individualised therapies, and from their use in transplantation and bioengineering. The use of autologous stem cells is highly desirable, as it avoids the problem of tissue rejection, and also reduces ethical and regulatory issues. Identification of the most appropriate cell sources for different potential applications, development of appropriate clinical grade methodologies and large scale well controlled clinical trials will be essential to assess safety and value of cell based therapies, which have been generating much hope, but are by and large not yet close to becoming standard clinical practice. We briefly discuss stem cells in the context of tissue repair and regenerative medicine, with a focus on individualised clinical approaches, and give examples of sources of autologous cells with potential for clinical intervention.

Cord blood banking: current status

OBJECTIVES

Cord blood is increasingly used as a hematopoietic progenitor cell source for bone marrow transplantation.

METHODS

Development of cord blood banks for altruistic use was essential to open the possibility of opting for cord blood therapy for patients lacking a conventional donor.

RESULTS

Cord blood has major advantages as a resource for donor provision. First, it universalizes the access to the therapy since it allows transplantation of partially matched HLA grafts, benefiting ethnicities less represented in the adult volunteer list. Second, it is an off-the-shelf, ready-to-use source that avoids donor risk and attrition. Third, potentially it has better long term sustainability if a defined optimal size of the inventory is achieved; currently, more than 80% of patients, regardless ethnicity, can find a reliable cord blood donor with the current worldwide inventory.

CONCLUSION

In order that this approach may definitely solve the problem of an equitable access to the therapy, two aspects need to be improved: the quality of CB inventories (driven by a higher stringency of regulatory requirements), and clinical outcomes, particularly understanding the appropriate donor selection and focusing research on accelerating the speed of engraftment and immune reconstitution.