Non-transplantable cord blood units as a source for adoptive immunotherapy of leukaemia and a paradigm of circular economy in medicine.

Advances in immunotherapy with T cells armed with chimeric antigen receptors (CAR-Ts), opened up new horizons for the treatment of B-cell lymphoid malignancies. However, the lack of appropriate targetable antigens on the malignant myeloid cell deprives patients with refractory acute myeloid leukaemia of effective CAR-T therapies. Although non-engineered T cells targeting multiple leukaemia-associated antigens [i.e. leukaemia-specific T cells (Leuk-STs)] represent an alternative approach, the prerequisite challenge to obtain high numbers of dendritic cells (DCs) for large-scale Leuk-ST generation, limits their clinical implementation. We explored the feasibility of generating bivalent-Leuk-STs directed against Wilms tumour 1 (WT1) and preferentially expressed antigen in melanoma (PRAME) from umbilical cord blood units (UCBUs) disqualified for allogeneic haematopoietic stem cell transplantation. By repurposing non-transplantable UCBUs and optimising culture conditions, we consistently produced at clinical scale, both cluster of differentiation (CD)34+ cell-derived myeloid DCs and subsequently polyclonal bivalent-Leuk-STs. Those bivalent-Leuk-STs contained CD8+ and CD4+ T cell subsets predominantly of effector memory phenotype and presented high specificity and cytotoxicity against both WT1 and PRAME. In the present study, we provide a paradigm of circular economy by repurposing unusable UCBUs and a platform for future banking of Leuk-STs, as a 'third-party', 'off-the-shelf' T-cell product for the treatment of acute leukaemias.

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

BACKGROUND: The umbilical cord blood bank at the Mexican Institute of Social Security (IMSS-CBB) was established in January 2005. This lead to the development of the UCB transplantation program. Herein, we describe the experience generated during these 13 years. STUDY DESIGN AND METHODS: Donor selection, as well as UCB collection, processing, and banking were performed under good manufacturing practices and standard operating procedures. UCB units were thawed, processed, and released for transplantation based on HLA and nucleated cell content. RESULTS: From January 2005-December 2017, 1,298 UCB units were banked; 164 of them were released for transplantation, and 118 UCB transplants were performed. Ninety-four transplants were performed in pediatric patients and 24 in adults. Sixty percent of them corresponded to patients with leukemia, 19% were patients with marrow failure, and the rest had immunodeficiency, hemoglobinopathy, metabolic disorders, or solid tumors. Engraftment was observed in 67 patients (57% of transplanted patients) and 64% of them were still alive when writing this article. In contrast, only 13 of the 51 (25%) non-engrafting patients were alive. At the time of writing this article, the disease-free survival rate was 37%, and the overall survival rate was 47%, with survival periods of 161-3,721 days. CONCLUSION: The IMSS UCB banking and transplantation program has had a significant impact for many IMSS patients. The hematopoietic transplantation program at our institution has benefited from the use of UCB as a source of transplantable cells.

Cord Blood Banking for Potential Future Transplantation.

This policy statement is intended to provide information to guide pediatricians, obstetricians, and other medical specialists and health care providers in responding to parents' questions about cord blood donation and banking as well as the types (public versus private) and quality of cord blood banks. Cord blood is an excellent source of stem cells for hematopoietic stem cell transplantation in children with some fatal diseases. Cord blood transplantation offers another method of definitive therapy for infants, children, and adults with certain hematologic malignancies, hemoglobinopathies, severe forms of T-lymphocyte and other immunodeficiencies, and metabolic diseases. The development of universal screening for severe immunodeficiency assay in a growing number of states is likely to increase the number of cord blood transplants. Both public and private cord blood banks worldwide hold hundreds of thousands of cord blood units designated for the treatment of fatal or debilitating illnesses. The procurement, characterization, and cryopreservation of cord blood is free for families who choose public banking. However, the family cost for private banking is significant and not covered by insurance, and the unit may never be used. Quality-assessment reviews by several national and international accrediting bodies show private cord blood banks to be underused for treatment, less regulated for quality control, and more expensive for the family than public cord blood banks. There is an unquestionable need to study the use of cord blood banking to make new and important alternative means of reconstituting the hematopoietic blood system in patients with malignancies and blood disorders and possibly regenerating tissue systems in the future. Recommendations regarding appropriate ethical and operational standards (including informed consent policies, financial disclosures, and conflict-of-interest policies) are provided for physicians, institutions, and organizations that operate or have a relationship with cord blood banking programs. The information on all aspects of cord blood banking gathered in this policy statement will facilitate parental choice for public or private cord blood banking.

Cord blood banking activities at a university hospital in northeast Mexico: an 8-year experience.

BACKGROUND: Umbilical cord blood (UCB) represents an alternative source of stem cells for transplantation for the treatment of hematologic malignancies and genetic disorders. There is scarce information detailing cord blood bank (CBB) collection and transplantation activities from developing countries. We documented our experience at a public university hospital in northeast Mexico. STUDY DESIGN AND METHODS: We carried out a retrospective and descriptive analysis of our CBB activity during an 8-year period from May 2002 to September 2010. Collection, processing, and cryopreservation of CB were carried out following standard operating procedures. The minimum volume and total nucleated cell (TNC) content for cryopreservation were 80 mL and 8.0 × 10(8) , respectively. RESULTS: A total of 1256 UCB units were collected; 428 (34%) were banked and 828 (66%) were discarded. The main reason for exclusion was biologic: low volume and/or low number of TNC accounted for 84% of the total discarded units. Cryopreserved cord blood units (CBUs) had a median volume of 113.8 mL (range, 80-213.2 mL) and 13.0 × 10(8) (range, 8 × 10(8) -36.6 × 10(8) ) TNCs. Cell viability was 99.3% (88-100%). The median CD34+ cell content was 4.0 × 10(6) (0.46 × 10(6) -19.38 × 10(6) ). Sixteen units have been released for transplantation, leading to a utilization rate of 3.7%. CONCLUSION: CBB demands considerable human and financial resources; it is then essential for centers at developing countries to share their experience, results, and databases to increase the probability of finding matching units for their patients. Efforts to create and maintain CBBs allow to offer this therapeutic option at an affordable cost.

Flow cytometry assessment of apoptotic CD34+ cells by annexin V labeling may improve prediction of cord blood potency for engraftment.

BACKGROUND: Nonviable CD34+ cells are commonly assessed by standard flow cytometry using the nuclear stain 7-aminoactinomycin D (7AAD). 7AAD, however, only detects necrotic and late apoptotic cells, not earlier apoptosis, which engraft poorly in animal models of cord blood (cord) transplantation. The standard method, therefore, may overestimate engraftment potency of cord units under certain conditions. STUDY DESIGN AND METHODS: To detect apoptotic events, costaining with 7AAD and annexin V (AnnV), in parallel with the quantitative, standard enumeration, was used. Cord units were assessed before and after cryopreservation using both staining methods and colony-forming units (CFU) to determine if graft potency can be predicted using a "functional flow cytometry" approach. RESULTS: Significant numbers of CD34+ AnnV+ events were found within the 7AAD-gated population. Nonapoptotic cell dose (CD34+ AnnV-) correlated well with CFUs in both a small-scale (n = 10) and a large-scale banking study (n = 107). Finally, following samples postthaw with time showed increasing numbers of apoptotic CD34+ cells and consequently the AnnV assessed dose was better at predicting the CFU compared with just the standard enumeration. CONCLUSION: Defining the apoptotic population of CD34+ cells improved the prediction of CFU, making this method a rapid test of potency for assessment of cord units for clinical use.

Family-directed umbilical cord blood banking.

Umbilical cord blood transplantation from HLA-identical siblings provides good results in children. These results support targeted efforts to bank family cord blood units that can be used for a sibling diagnosed with a disease which can be cured by allogeneic hematopoietic stem cell transplantation or for research that investigates the use of allogeneic or autologous cord blood cells. Over 500 patients transplanted with related cord blood units have been reported to the Eurocord registry with a 4-year overall survival of 91% for patients with non-malignant diseases and 56% for patients with malignant diseases. Main hematologic indications in children are leukemia, hemoglobinopathies or inherited hematologic, immunological or metabolic disorders. However, family-directed cord blood banking is not widely promoted; many cord blood units used in sibling transplantation have been obtained from private banks that do not meet the necessary criteria required to store these units. Marketing by private banks who predominantly store autologous cord blood units has created public confusion. There are very few current validated indications for autologous storage but some new indications might appear in the future. Little effort is devoted to provide unbiased information and to educate the public as to the distinction between the different types of banking, economic models and standards involved in such programs. In order to provide a better service for families in need, directed-family cord blood banking activities should be encouraged and closely monitored with common standards, and better information on current and future indications should be made available.

Quality assessment of umbilical cord blood units at the time of transplantation.

Total nucleated cell (TNC) count, CD34(+) cell count, colony-forming unit-granulocyte-macrophage (CFU-GM) content, and cell viability impact the outcome of umbilical cord blood (UCB) transplantation. Assessments of unit quality have usually been provided by cord blood banks (CBBs), but it is unclear whether pre-freezing tests or pre-transplant release tests performed by CBBs are reproducible. The aim of this study was to compare the UCB characteristics analyzed at the site of infusion of the UCB with those provided by CBBs. Samples were taken from 54 UCB units for assessment of post-thaw characteristics. TNC counts and CD34(+) cell contents measured at our hospital before infusion showed good correlations with values assessed in pre-freezing tests (r = 0.900 and 0.943, respectively) and pre-transplant release tests (r = 0.829 and 0.930, respectively). Our data reveal that the TNC counts and CD34(+) cell contents determined by pre-freezing and pre-transplant release tests, which are the most important UCB unit selection criteria, accurately reflected the quality of infused UCB units. However, CFU-GM content was poorly correlated (r = 0.560 and 0.606). Correlation of post-thaw cell viabilities measured before infusion and during the pre-transplant release tests was also poor (r = 0.308). We suggest that the TNC count and CD34(+) cell content estimated before cryopreservation and in pre-transplant release tests provided by CBBs are reproducible and can assist the transplant physicians in selection of appropriate UCB units.

Quality assessment of cord blood units selected for unrelated transplantation: a transplant center perspective.

Cord blood units (CBUs) are increasingly being used for unrelated allogeneic stem cell transplantation and their selection is mainly done according to pre-freezing cell dose and HLA donor/recipient compatibility. The main practical advantage of cord blood transplant (CBT) is represented by an easy and quick CBU procurement, due to the possibility of long-term storage of fully HLA typed CBUs assessed for cell dose and infectious contamination. The main disadvantage consists in a limited cell dose, with the consequent risk of graft failure or engraftment delay. In order to warrant the safety and the efficiency of CBUs selected for clinical use, transplant physicians may check CBU characteristics by requiring quality assessments (QAs) to the cord blood bank (CBB), to be performed on segments attached to and cryopreserved with the bags. However, there is a wide variability concerning CBU-QA with regard to the pre-transplant "release tests", mainly due to limited availability of segments attached to the CBU and of maternal samples and to difficult communication between Transplant Centres (TCs) and CBBs. The aim of this article is to describe a TC perspective during CBU selection for unrelated transplant, in order to identify an appropriate QA scheme and define the timing when the results need to be acquired. By analyzing the available data, this article describes a model of TC-QA policy able to guide the clinician from CBU selection through the infusion, with the ultimate aim of improving the transplant clinical outcome.

Assessment of cord blood unit characteristics on the day of transplant: comparison with data issued by cord blood banks.

BACKGROUND: Selection of a cord blood (CB) unit for allogeneic transplantation relies on graft characterization results provided by cord blood banks (CBBs). The goal was to compare the graft characterization results obtained upon thawing and washing to those provided by CBBs at selection. STUDY DESIGN AND METHODS: With tests that assess CB graft characteristics known to impact engraftment, CB units have been analyzed after thaw and before infusion. Our results were compared to data provided by CBBs to determine the impact on engraftment and assess how CBB-supplied information can affect future CB unit selection. RESULTS: Variability was noted as to the type of information provided by the different CBBs. Also, variability was found between the information provided by CBBs and the graft characterization results obtained upon thawing and washing. In some cases, CB measures known to be predictive of engraftment were found much lower than reported by CBBs. Only the total nucleated cell count, which is the main CB graft selection criterion besides HLA matching, correlated favorably. CONCLUSIONS: Our data reveal a high degree of variability in graft characteristics provided by CBBs and often poor correlation with results obtained on thawed and washed CB units. We suggest that standardized laboratory procedures aimed at graft characterization should be used by both CBBs and transplant centers to avoid unacceptable discrepancies.