Search

Abstract Multipotent mesenchymal stromal cells (MSC) offer new therapeutic opportunities based on their ability to modulate an imbalanced immune system. Immunomodulatory potency is typically demonstrated in vitro by measuring the presence of surrogate markers (i.e., indoleamine-2,3-dioxygenase, IDO; tumor necrosis factor receptor type 1, TNFR1) and/or functional assays in co-cultures (i.e., inhibition of lymphoproliferation, polarization of macrophages). However, the biological variability of reagents used in the latter type of assays leads to unreliable and difficult to reproduce data therefore making cross-comparison between batches difficult, both at the intra- and inter-laboratory levels. Herein, we describe a set of experiments aiming at the definition and validation of reliable biological reagents as a first step towards standardization of a potency assay. This approach is based on the co-culture of Wharton’s jelly (WJ)-derived MSC and cryopreserved pooled peripheral blood mononuclear cells. Altogether, we successfully defined a robust and reproducible immunopotency assay based on previously described methods incorporating substantial improvements such as cryopreservation of multiple vials of pooled peripheral blood mononuclear cells (PBMC) from 5 individual donors that enable a number of tests with same reagents, also reducing waste of PBMC from individual donors and therefore contributing to a more efficient and ethical method to use substances of human origin (SoHO). The new methodology was successfully validated using 11 batches of clinical grade MSC,WJ. Methods described here contribute to minimize PBMC donor variability while reducing costs, streamlining assay setup and convenience and laying the foundations for harmonization of biological reagents usage in standardized immunopotency assays for MSC. Highlights • The use of pools of peripheral blood mononuclear cells (PBMCs) in potency assays contributes to robust and reproducible results, which is key in the assessment of mesenchymal stroma cells (MSC) potency for batch release. • Cryopreservation of PBMCs does not impact negatively on their activation and proliferation abilities. • Cryopreserved pools of PBMC constitutes convenient off-the-shelf reagents for potency assays. • Cryopreservation of pooled PBMCs from multiple donors is a way to reduce waste of donated PBMC and its associated costs, as well as reducing the impact of individual donor variability of substances of human origin (SoHO).

Commodification; Human substances Mercantilització; Substàncies humanes Mercantilización; Sustancias humanas In view of the public consultation recently launched by the World Health Organization on Regulatory Convergence of Cell and Gene Therapy Products and the Proposal for a Regulation on substances of human origin (SoHO) repealing the European Union Directives on Blood and on Tissues and Cells, an opportunity arises to define an ethical and transparent framework of collaboration between industry and authorities responsible for SoHO-derived products, comprising medicines, medical devices, transfusion, and transplantation. The commodification of SoHO-derived medicinal products and medical devices entails important risks to the sustainability of healthcare systems and threatens the equitable access of patients to innovative therapies. It may also jeopardize the principle of altruistic donation of SoHO that is required for the treatment and survival of thousands of patients every year. This article puts forward several proposals aimed at reconciling the ethical principles of voluntary and unpaid SoHO donation and the noncommercialization of the human body with obtaining a profit that allows business activities, while ensuring high quality, safety, and efficacy standards of tissues and cells for clinical use.

Hematopoietic stem cell (HSC) transplantation is crucial to cure hematologic malignancies. Umbilical cord blood (UCB) is a source of stem cells, but 90% of UCB units are discarded due to low cellularity. Improving the engraftment capacities of CD34+ stem cells would allow the use of UCB that were so far rejected. Betamethasone induces long-term transcriptomic and epigenomic changes in immune cells through glucocorticoid receptor. We hypothesize that discarded UCB could be used owing to improvements induced by betamethasone. Isolated CD34+ HSC from UCB were exposed to the synthetic glucocorticoids betamethasone and fluticasone for 20 h, and cell phenotype was determined before transplantation. NSG mice were sub-lethally irradiated (1 Gy or 2 Gy) 6 h before intravenously transferring 2–5 × 105 CD34+ HSC. The peripheral blood engraftment levels and the leukocyte subsets were followed up for 20 weeks using flow cytometry. At end point, the engraftment and leukocyte subsets were determined in the spleen and bone marrow. We demonstrated that betamethasone has surprising effects in recovering immune system homeostasis. Betamethasone and fluticasone increase CXCR4 and decrease HLA class II and CD54 expression in CD34+ HSCs. Both glucocorticoids-exposed cells showed a similar engraftment in 2 Gy-irradiated NSG mice. Interestingly, betamethasone-exposed cells showed enhanced engraftment in 1 Gy-irradiated NSG mice, with a trend to increase regulatory T cell percentage when compared to control. Betamethasone induces alterations in CD34+ HSCs and improve the engraftment, leading to a faster immune system recovery, which will contribute to engrafted cells survival.

STUDY QUESTIONCan risks associated with novelties in assisted reproduction technologies (ARTs) be assessed in a systematic and structured way?SUMMARY ANSWERAn ART-specific risk assessment tool has been developed to assess the risks associated with the development of novelties in ART (EuroGTP II-ART).WHAT IS KNOWN ALREADYHow to implement new technologies in ART is well-described in the literature. The successive steps should include testing in animal models, executing pre-clinical studies using supernumerary gametes or embryos, prospective clinical trials and finally, short- and long-term follow-up studies on the health of the offspring. A framework categorizing treatments from experimental through innovative to established according to the extent of the studies conducted has been devised. However, a systematic and standardized methodology to facilitate risk evaluation before innovations are performed in a clinical setting is lacking.STUDY DESIGN, SIZE, DURATIONThe EuroGTP II-ART risk assessment tool was developed on the basis of a generic risk assessment algorithm developed for tissue and cell therapies and products (TCTPs) in the context of the project ‘Good Practices for demonstrating safety and quality through recipient follow-up European Good Tissue and cells Practices II (EuroGTP II)’. For this purpose, a series of four meetings was held in which eight ART experts participated. In addition, several tests and simulations were undertaken to fine-tune the final tool.PARTICIPANTS/MATERIALS, SETTING, METHODSThe three steps comprising the EuroGTP II methodology were evaluated against its usefulness and applicability in ART. Ways to improve and adapt the methodology into ART risk assessment were agreed and implemented.MAIN RESULTS AND THE ROLE OF CHANCEAssessment of the novelty (Step 1), consisting of seven questions, is the same as for other TCTPs. Practical examples were included for better understanding. Identification of potential risks and consequences (Step 2), consisting of a series of risks and risk consequences to consider during risk assessment, was adapted from the generic methodology, adding more potential risks for processes involving gonadic tissues. The algorithm to score risks was also adapted, giving a specific range of highest possible risk scores. A list of strategies for risk reduction and definition of extended studies required to ensure effectiveness and safety (Step 3) was also produced by the ART experts, based on generic EuroGTP II methodology. Several explanations and examples were provided for each of the steps for better understanding within this field.LIMITATIONS, REASONS FOR CAUTIONA multidisciplinary team is needed to perform risk assessment, to interpret results and to determine risk mitigation strategies and/or next steps required to ensure the safety in the clinical use of novelties.WIDER IMPLICATIONS OF THE FINDINGSThis is a dynamic tool whose value goes beyond assessment of risk before implementing a novel ART in clinical practice, to re-evaluate risks based on information collected during the process.STUDY FUNDING / COMPETING INTEREST(S)This study was called EUROGTP II and was funded by the European Commission (Grant agreement number 709567). The authors declare no competing interests concerning the results of this study.

Allele-level HLA compatibility in cord blood transplantation, together with noninherited maternal antigen or NIMA matching, have been associated with better transplant outcomes. The aim of this work is to develop a cost-efficient high-resolution HLA typing strategy based on next-generation sequencing to improve the quality of the Barcelona Cord Blood Bank's inventory, and to investigate the impact of high-resolution HLA typing and NIMA determination on the preferential selection of cord blood for transplantation. In this line, the developed strategy was validated and the HLA-A, -B, -C, -DRB1, and -DQB1 genes of 5000 cord blood units and 2500 of their associated maternal samples were typed. Subsequently, three study groups of 2012 units each were monitored for up to 2 years: (1) units with high-resolution and maternal HLA typing, (2) units with high-resolution but not maternal typing, and (3) units typed at low-resolution for class I and only high-resolution for HLA-DRB1. Despite a trend toward a greater selection of units with high-resolution typing, no significant impact of these variables was observed. These results highlight the need for evidence-based and globally accepted criteria for cord blood selection, together with the necessity to improve the accessibility of clinicians to donor registry's data.

Difficulties in the collection of hematopoietic stem and progenitor cells (HSPCs) from Fanconi anemia (FA) patients have limited the gene therapy in this disease. We have investigated (ClinicalTrials.gov, NCT02931071) the safety and efficacy of filgrastim and plerixafor for mobilization of HSPCs and collection by leukapheresis in FA patients. Nine of eleven enrolled patients mobilized beyond the threshold level of 5 CD34+ cells/μL required to initiate apheresis. A median of 21.8 CD34+ cells/μL was reached at the peak of mobilization. Significantly, the oldest patients (15 and 16 years old) were the only ones who did not reach that threshold. A median of 4.27 million CD34+ cells/kg was collected in 2 or 3 aphereses. These numbers were markedly decreased to 1.1 million CD34+ cells/kg after immunoselection, probably because of weak expression of the CD34 antigen. However, these numbers were sufficient to facilitate the engraftment of corrected HSPCs in non-conditioned patients. No procedure-associated serious adverse events were observed. Mobilization of CD34+ cells correlated with younger age, higher leukocyte counts and hemoglobin values, lower mean corpuscular volume, and higher proportion of CD34+ cells in bone marrow (BM). All these values offer crucial information for the enrollment of FA patients for gene therapy protocols., Graphical abstract, Mobilization and collection of HSPCs from FA patients with sufficient HSPC reserve is a safe and efficient procedure, incorporating filgrastim and plerixafor as mobilization agents. Adequate HSPC mobilization correlates with younger age, higher leukocyte counts and hemoglobin values, lower mean corpuscular volume, and higher BM CD34+ cell numbers.

Background iPSC (induced pluripotent stem cells) banks of iPSC lines with homozygous HLA (human leukocyte antigen) haplotypes (haplobanks) are proposed as an affordable and off-the-shelf approach to allogeneic transplantation of iPSC derived cell therapies. Cord blood banks offer an extensive source of HLA-typed cells suitable for reprogramming to iPSC. Several initiatives worldwide have been undertaken to create national and international iPSC haplobanks that match a significant part of a population. Methods To create an iPSC haplobank that serves the Spanish population (IPS-PANIA), we have searched the Spanish Bone Marrow Donor Registry (REDMO) to identify the most frequently estimated haplotypes. From the top ten donors identified, we estimated the population coverage using the criteria of zero mismatches in HLA-A, HLA-B, and HLA-DRB1 with different stringencies: high resolution, low resolution, and beneficial mismatch. Results We have calculated that ten cord blood units from homozygous donors stored at the Spanish cord blood banks can provide HLA-A, HLA-B, and HLA-DRB1 matching for 28.23% of the population. Conclusion We confirm the feasibility of using banked cord blood units to create an iPSC haplobank that will cover a significant percentage of the Spanish and international population for future advanced therapy replacement strategies.

Donor lymphocytes infusions (DLIs) are a major therapeutic approach to treat relapse and mixed chimerism after allogeneic hematopoietic cell transplant (alloHCT). The impact of the composition regarding different cell subsets in the development of graft-versus-host disease (GVHD) is not fully understood. We performed a cell subsets analysis of 56 DLIs from fully HLA-compatible identical matched sibling donors (MSDs) in 36 alloHCT patients and studied its association with GVHD. A median of one DLI was infused per patient. Fourteen patients (38%) developed GVHD. The cell composition analysis of the first DLI (DLI1) showed that a high dose of B cells (P = .03) and CD27+ B cells (P 3 × 106 cells/kg, CD27+ B cells >2.6 × 106/kg, CD27+ NK >0.35 × 106 cells/kg, and mononuclear cells >0.83 × 108/kg). Noteworthy, the proportion of CD4+ naive T cells (TN) or unselected TN was not linked with GVHD and a DLI1 containing a higher dose of regulatory T cells was not protective for GVHD. We studied several transplant clinical variables and did not find any association with GVHD. Altogether, this study provides a comprehensive analysis of the cell populations in a DLI from MSDs and identifies potential key cell subsets, which provides insight for the understanding of GVHD after DLI.

Use of adoptive immunotherapy with virus-specific T cells (VST) in patients with inborn errors of immunity prior to hematopoietic stem cell transplantation (HSCT) has been reported in few patients. We report our experience, reviewing all the cases previously reported. We report four children with inborn errors of immunity who received VST infusion in a pre-HSCT setting in two reference centers in Spain and review all inborn errors of immunity cases previously reported. Taking into account our four cases, nine children have been reported to receive VST prior to HSCT to date: 3 severe combined immunodeficiency, 2 CTPS1 deficiency, 1 dyskeratosis congenital, 1 ORAI1 deficiency, 1 Rothmund-Thomson syndrome, and 1 combined immunodeficiency without confirmed genetic defect. In four patients, immunotherapy resulted in clinical improvement, allowing to proceed to HSCT. In these cases, the infusion was started closely to viral diagnosis [mean time 28 days (IQR; 17–52 days)], and the VST was followed shortly thereafter by HSCT [mean time 28 days (IQR; 10–99 days)]. Viremia was controlled after HSCT in two cases (performed 7 and 36 days after the infusion). Multiple infusions were required in many cases. Five out of nine patients died before receiving HSCT. These patients presented with a prolonged and uncontrolled infection before VST administration [mean time from viral diagnosis to VST infusion was 176 days (IQR; 54–1687)]. In patients with inborn errors of immunity, the efficacy of VST for treating disseminated viral infections in pre-transplant settings seems to have a limited efficacy. However, this therapy could be used in a pre-emptive setting before severe viral disease occurs or closely to HSCT.

Haploidentical related (Haplo) and umbilical cord blood (UCB) donors are the main "alternative donor" options for allogeneic hematopoietic stem cell transplantation (HCT) for patients without identical donor. At our institution, UCB was the main alternative donor type until 2013, when HaploHCT was introduced as the preferred procedure. A common myeloablative conditioning regimen was used, based on thiotepa, busulfan, and fludarabine. We analyze the outcomes of 47 patients (61%) who received a single UCB transplantation ( UCBT) and 30 patients (39%) who received a HaploHCT with post-transplant cyclophosphamide. No differences were found in the rate of neutrophil engraftment, whereas platelet recovery was earlier with HaploHCT. NRM was higher after UCBT at 3 months and 3 years (13% and 13% vs. 23% and 45% in HaploHCT and UCBT, respectively; p < 0.001 for both time points). The 3-year relapse incidence was 35% after HaploHCT vs. 17% after UCBT, respectively (p = 0.13). The 100-day incidence of grade 3-4 acute GVHD (3% vs. 11%) and the 3-year moderate-to-severe chronic GVHD (4% vs. 15%) did not differ between HaploHCT and UCBT, respectively (p > 0.2). There was a trend for higher overall survival at 1 and 3 years in HaploHCT recipients (69% vs. 45% and 64% vs. 38%, respectively; p = 0.055 for both time points). Despite the small sample sizes, multivariate analysis adjusted for patient age and disease status at transplant showed a better 3-year OS in HaploHCT recipients, mostly due to a lower NRM (p < 0.001). Our results support the use of HaploHCT when feasible when an identical donor is not available.

Allele-level HLA compatibility in cord blood transplantation has been associated with better transplant outcomes and is recommended as a selection criterion. It is also a crucial aspect for other therapeutic applications involving cord blood-derived cells. Determination of high-resolution HLA frequencies is an important step towards improving the quality of cord blood banks. We analyzed HLA-A, -B, -C, -DRB1, and -DQB1 allele frequencies in 5458 high-quality cord blood units from the Barcelona Cord Blood Bank and identified 275 class I and 121 class II HLA alleles. A*02:01, B*44:03, C*07:01, DRB1*07:01 and DQB1*03:01 were the most frequent alleles at each locus. We detected 26 novel alleles and were able to determine the presence or absence of some null alleles, including C*04:09N, in a large number of units. We also analyzed maternal HLA typing information for 1877 units to determine real haplotype frequencies and linkage disequilibrium. A*29:02-B*44:03-C*16:01-DRB1*07:01-DQB1*02:02 was the most frequent HLA haplotype and the DRB1-DQB1 gene pair contained the two-locus haplotypes with the strongest linkage disequilibrium values. Four of the 11 unique haplotypes identified in the HLA-homozygous cord blood units were the top-ranking haplotypes identified and were present in 18% of the cohort. This is the first study to report on HLA allele and haplotype frequencies for umbilical cord blood units from the Barcelona Cord Blood Bank and the largest study to date involving two fields of HLA resolution typing of Spanish registry data.

Allogeneic cell therapy; Haplotype frequency; Heart failure Teràpia cel·lular al·logènica; Freqüència haplotípica; Insuficiència cardíaca Terapia celular alogénica; Frecuencia haplotípica; Insuficiencia cardíaca AIMS: Cell therapy can be used to repair functionally impaired organs and tissues in humans. Although autologous cells have an immunological advantage, it is difficult to obtain high cell numbers for therapy. Well-characterized banks of cells with human leukocyte antigens (HLA) that are representative of a given population are thus needed. The present study investigates the HLA allele and haplotype frequencies in a cohort of heart failure (HF) patients. METHODS AND RESULTS: We carried out the HLA typing and the allele and haplotype frequency analysis in 247 ambulatory HF patients. We determined HLA class I (A, B, and C) and class II (DRB1 and DQB1) using next-generation sequencing technology. The allele frequencies were obtained using Python for Population Genomics (PyPop) software, and HLA haplotypes were estimated using HaploStats. A total of 30 HLA-A, 56 HLA-B, 23 HLA-C, 36 HLA-DRB1, and 15 HLA-DQB1 distinct alleles were identified within the studied cohort. The genotype frequencies of all five HLA loci were in Hardy-Weinberg equilibrium. We detected differences in HLA allele frequencies among patients when the etiological cause of HF was considered. There were a total of 494 five-loci haplotypes, five of which were present six or more times. Moreover, the most common estimated HLA haplotype was HLA-A*01:01, HLA-B*08:01, HLA-C*07:01, HLA-DRB1*03:01, and HLA-DQB1*02:01 (6.07% haplotype frequency per patient). Remarkably, the 11 most frequent haplotypes would cover 31.17% of the patients of the cohort in need of allogeneic cell therapy. CONCLUSIONS: Our findings could be useful for improving allogeneic cell administration outcomes without concomitant immunosuppression.

The newborn’s blood left in the placenta after delivery (usually termed “placental blood” or “umbilical cord blood,” UCB) contains a large number of therapeutically valuable hemopoietic stem and progenitor cells. UCB can be donated to the community for solidarity purposes by informed, consenting parents [1, 2]. After collection by venipuncture of umbilical cord vessels by trained midwives or other health operators, UCB is transported at controlled temperature to UCB banks, where it is processed, cryopreserved, and stored in liquid nitrogen for future use in hemopoietic transplant procedures performed in patients suffering from severe blood diseases.

Graft-versus-host disease (GVHD) is among the most challenging complications in unrelated donor hematopoietic cell transplantation (HCT). The highly polymorphic MHC class I chain-related gene A, MICA, encodes a stress-induced glycoprotein expressed primarily on epithelia. MICA interacts with the invariant activating receptor NKG2D, expressed by cytotoxic lymphocytes, and is located in the MHC, next to HLA-B. Hence, MICA has the requisite attributes of a bona fide transplantation antigen. Using high-resolution sequence-based genotyping of MICA, we retrospectively analyzed the clinical effect of MICA mismatches in a multicenter cohort of 922 unrelated donor HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 10/10 allele-matched HCT pairs. Among the 922 pairs, 113 (12.3%) were mismatched in MICA. MICA mismatches were significantly associated with an increased incidence of grade III-IV acute GVHD (hazard ratio [HR], 1.83; 95% confidence interval [CI], 1.50-2.23; P < .001), chronic GVHD (HR, 1.50; 95% CI, 1.45-1.55; P < .001), and nonelapse mortality (HR, 1.35; 95% CI, 1.24-1.46; P < .001). The increased risk for GVHD was mirrored by a lower risk for relapse (HR, 0.50; 95% CI, 0.43-0.59; P < .001), indicating a possible graft-versus-leukemia effect. In conclusion, when possible, selecting a MICA-matched donor significantly influences key clinical outcomes of HCT in which a marked reduction of GVHD is paramount. The tight linkage disequilibrium between MICA and HLA-B renders identifying a MICA-matched donor readily feasible in clinical practice.

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 × 10(6) total nucleated cells and 4 × 10(6) 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.

Relapse of acute leukemia (AL) after allogeneic hematopoietic cell transplantation (Allo-HCT) entails a dismal prognosis. In this scenario, donor lymphocyte infusions (DLIs) and second Allo-HCT are two major approaches. We compared outcomes of AL patients treated for relapse with DLI or second Allo-HCT after receiving debulking therapy. In total, 46 patients were included in the study; 30 (65%) had acute myeloid leukemia and 16 (35%) had acute lymphoblastic leukemia. The median age was 38 years (range 4-66). Twenty-seven patients received a second Allo-HCT and 19 patients received DLI. The median follow-up of the cohort was 273 days (range 9-7013). Overall survival (OS), disease-free survival (DFS), nonrelapse mortality, and cumulative incidence (CI) of relapse were calculated from DLI or second Allo-HCT date. In univariate analysis, second Allo-HCT was associated with higher OS (p = 0.021) and a trend to higher DFS (p = 0.097) and CI of relapse (p = 0.094) on univariate analysis. However, multivariate analysis showed comparable outcomes between DLI and second Allo-HCT, with the time interval to relapse before DLI or second Allo-HCT the only statistically significant factor with an impact on OS and DFS. Within the DLI cohort, T-cell-depleted Allo-HCT was associated with higher OS (p = 0.003) and DFS (p < 0.001) and lower CI of relapse (p = 0.002) than T-cell-replete Allo-HCT. Overall, in this cohort of AL patients, second Allo-HCT and DLI associated similar outcomes. As in other relapse studies, the length of remission (time to relapse) was identified as a factor with statistical impact on survival. Further studies are warranted. (C) 2018 ISEH Society for Hematology and Stem Cells. Published by Elsevier Inc. All rights reserved.

HLA haplobank; SOP; Cell therapy Haplobanc d'HLA; Procediment operatiu estàndard; Teràpia cel·lular Haplobanco de HLA; Procedimiento operativo estándar; Terapia celular In this article, we will discuss the main aspects to be considered to define standard operation procedures (SOPs) for the creation of an induced pluripotent stem cell (iPSC) bank using cord blood (CB)-or similar cell type-bank guidelines for clinical aims. To do this, we adapt the pre-existing SOP for CB banking that can be complementary for iPSCs. Some aspects of iPSC manufacturing and the particular nature of these cells call for special attention, such as the potential multiple applications of the cells, proper explanation to the donor for consent of use, the genomic stability and the risk of genetic privacy disclosure. Some aspects of the iPSC SOP are solidly established by CB banking procedures, other procedures have good consensus in the scientific and medical community, while others still need to be further debated and settled. Given the international sharing vocation of iPSC banking, there is an urgent need by scientists, clinicians and regulators internationally to harmonize standards and allow future sample interchange between many iPSC bank initiatives that are springing up worldwide. Funded by Spanish Ministry of Science, Innovation and Universities, National Plan for Scientific and Technical Research and Innovation 2013–2016 RETOS COLABORACIÓN Program 2017: exp. RTC-2017-6000-1. 2017–2021; Spanish Cell Therapy Network (TerCel, exp. No. RD16/0011/0028); AdvanceCat with the support of ACCIÓ (Catalonia Trade & Investment; Generalitat de Catalunya) under the Catalonian ERDF operational program (European Regional Development Fund) 2014–2020; TV3 Maraton 2018–FBG project 309768 (M.J.E)

In the original version of this article, author ‘Lucia Lopez-Corral’ was incorrectly listed as ‘Lucia Lopez’. This has now been corrected in both the PDF and HTML versions of the article to ‘Lucia Lopez-Corral’.

Background and objective Poor mobilisation of peripheral blood stem cells (CD34+ cells) from bone marrow is a frequent reason for not reaching the autologous stem cell transplantation (SCT) procedure in patients diagnosed with lymphoma or myeloma. Plerixafor, a reversible inhibitor of the binding of stromal cell-derived factor 1 to its cognate receptor CXCR4, has demonstrated a higher capacity for the mobilisation of peripheral blood stem cells in combination with granulocyte colony stimulating factor (G-CSF) compared with G-CSF alone. For this reason, plerixafor is now indicated for poor mobiliser myeloma or lymphoma patients. Some studies have recently indicated that a pre-emptive strategy of plerixafor use during first mobilisation, according to the number of CD34+ mobilised cells in peripheral blood or to the harvested CD34+ cells after first apheresis, could avoid mobilisation failures and re-mobilizations, as well as the delay of autologous SCT. The aim of this consensus was to perform a review of published studies on pre-emptive strategy and to establish common recommendations for hospitals in Catalonia and Balearics on the use of pre-emptive plerixafor. Methods For the Consensus, physicians from participant hospitals met to review previous studies as well as previous own data about plerixafor use. The GRADE system was used to qualify the available evidence and to establish recommendations on the use of pre-emptive plerixafor. Results and conclusions After a review of the literature, the expert consensus recommended the administration of pre-emptive plerixafor for multiple myeloma or lymphoma patients with a CD34+ cell count lower than 10 cells/μL in peripheral blood (measured in the morning of day 4 of mobilisation with G-CSF or after haematopoietic recovery in the case of mobilisation with chemotherapy plus G-CSF).

The limited number of progenitor stem cells in umbilical cord blood (UCB) enforces the optimization and strict control of all the procedures involved in its therapeutic use—ie, collection, processing, cryopreservation, thawing, and transportation—to ensure graft potency at transplantation. For this reason, international UCB standards recommend storage of a cell sample attached to the UCB unit as a quantitative and functional control of the unit selected for transplantation. To validate the use of the sample attached to the UCB unit as a quality-control tool for the final product, UCB units (n = 20) stored in liquid nitrogen with the Bioarchive system were analyzed. The UCB units and their attached segments were thawed, and the number and viability of total nucleated cells, mononucleated cells, CD45+ cells, and CD34+ cells were determined, as were colony-forming cell counts. There was no significant difference between UCB units and segments for any of the parameters assessed. Additionally, the linear correlation coefficient (R2) in these paired samples was 0.85 and 0.78 for CD34+ cells and colony-forming cells, respectively. In conclusion, the cell sample in the tube segment physically linked to the transplant UCB bag predicts the total cell content and functionality of the unit and may serve as a source for final quality control of the UCB unit before transplantation.

on behalf of Eurocord, Cord Blood Committee EBMT and Netcord; International audience; Umbilical cord blood transplant recipients are exposed to an increased risk of graft failure, a complication leading to a higher rate of transplant-related mortality. The decision and timing to offer a second transplant after graft failure is challenging. With the aim of addressing this issue, we analyzed engraftment kinetics and outcomes of 1268 patients (73% children) with acute leukemia (64% acute lymphoblastic leukemia, 36% acute myeloid leukemia) in remission who underwent single-unit umbilical cord blood transplantation after a myeloablative conditioning regimen. The median follow-up was 31 months. The overall survival rate at 3 years was 47%; the 100-day cumulative incidence of transplant-related mortality was 16%. Longer time to engraftment was associated with increased transplant-related mortality and shorter overall survival. The cumulative incidence of neutrophil engraftment at day 60 was 86%, while the median time to achieve engraftment was 24 days. Probability density analysis showed that the likelihood of engraftment after umbilical cord blood transplantation increased after day 10, peaked on day 21 and slowly decreased to 21% by day 31. Beyond day 31, the probability of engraftment dropped rapidly, and the residual probability of engrafting after day 42 was 5%. Graft failure was reported in 166 patients, and 66 of them received a second graft (allogeneic, n=45). Rescue actions, such as the search for another graft, should be considered starting after day 21. A diagnosis of graft failure can be established in patients who have not achieved neutrophil recovery by day 42. Moreover, subsequent transplants should not be postponed after day 42.

BACKGROUND: The aim of this study was to assess the feasibility of freezing mobilized peripheral blood progenitor cell (PBPC) components at higher cell concentrations than are classically recommended for bone marrow. This approach might have potential benefits, such as lower cost of processing and storage and less risk of the complications associated with the transfusion of large component volumes and large quantities of DMSO. STUDY DESIGN AND METHODS: In the first phase, small aliquots of 19 apheresis components were cryopreserved at standard and higher cell concentrations (Aliquots A and B, respectively). In the second phase, 21 apheresis components were split into two bags each and frozen at standard (Bag A) and high (Bag B) cell concentrations. The differences in viability, cloning efficiency, and nucleated cell recovery in Bags A and B were examined. Finally, the hematologic recovery of 10 patients who underwent autologous transplantation with PBPC components frozen at high cell concentrations was analyzed. RESULTS: The median cell concentration at freezing was 94 (57-100) x 10 6 per mL and 291 (220-467) x 10 6 per mL for Aliquots A and B, respectively, and 90.9 (45.4-92) × 10 6 per mL and 332 (171-582) x 10 6 per mL for Bags A and B, respectively. The viability was significantly lower in samples frozen at higher cell concentrations: 92 versus 83 percent (p = 0.001) and 87 versus 77 percent (p

Resumen Fundamento y objetivo El fracaso de movilizacion de progenitores hematopoyeticos a sangre periferica (celulas CD34 + ) desde el compartimento medular es una causa frecuente de no realizacion de trasplante autogenico de progenitores hematopoyeticos (TAPH) en pacientes con linfoma o mieloma. Plerixafor, un inhibidor reversible de la union del factor derivado del estroma 1 con su receptor CXCR4, ha demostrado mayor movilizacion de progenitores hematopoyeticos cuando se administra junto con granulocyte colony stimulating factor (G-CSF, «factor estimulante de colonias granulociticas»), respecto a la movilizacion con G-CSF solo, por lo que en la actualidad esta indicado en pacientes con mieloma o linfoma y escasa capacidad de movilizacion. En los ultimos anos algunos estudios han senalado que una estrategia de administracion anticipada de plerixafor durante la primera movilizacion, basada en el numero de celulas CD34 + movilizadas a sangre periferica o en la celularidad obtenida en la primera aferesis, podria evitar fracasos de movilizacion y nuevas movilizaciones, asi como el retraso del ulterior trasplante. El objetivo del presente consenso fue realizar una revision de la bibliografia y establecer unas recomendaciones comunes para hospitales de Cataluna y Baleares para la utilizacion de una estrategia de administracion anticipada de plerixafor. Metodos Para la elaboracion del documento de consenso se realizaron reuniones presenciales en las que se realizo una revision de la bibliografia y de datos propios procedentes de los hospitales participantes. Para calificar el grado de la evidencia disponible y establecer las recomendaciones de uso anticipado de plerixafor se ha utilizado el sistema GRADE. Resultados y conclusiones Tras la revision de la bibliografia, el consenso de expertos definio que con un recuento inferior a 10 celulas CD34 + /μl en sangre periferica (determinado en la manana del dia cuarto de la movilizacion con G-CSF solo o en el dia de la recuperacion hemoperiferica tras la movilizacion con quimioterapia seguida de G-CSF) se recomienda la administracion anticipada de plerixafor.

Notch signals are critical for T-cell development, limiting the differentiation potential of multipotent progenitors arriving in the thymus via the bloodstream. Notch ligands Delta-like and Jagged are expressed in the bone marrow and, consequently, a role in the regulation of early events of adult hematopoiesis has been proposed. However, mice with disruptions in the Notch pathway do not show gross defects in the hematopoietic stem cell compartment, limiting Notch effects at later stages of development. In this study, we identify cord blood CD34 + CD38 − CD45RA − CD90 + cells, a recently described population of hematopoietic stem cells, as one of the earliest targets of Notch in human hematopoiesis. Upon Notch activation, CD34 + CD38 − cells are blocked in their differentiation at the CD34 + CD38 − CD45RA − CD90 + stage. Importantly, population and clonal analysis demonstrate that Delta-like–1 exposure does not affect lymphoid vs myeloid decisions. However, Notch signaling is required before lymphoid commitment to preserve T-cell potential of CD34 + CD38 − CD45RA − CD90 + cells. Our experiments also show that in terms of differentiation potential, CD34 + CD38 − CD45RA − CD90 + cells cultured in the presence of Notch signals, resemble cells directly isolated from cord blood. These results could have implications for translational efforts in the design of strategies aimed to accelerate immune reconstitution after transplantation.

BACKGROUND This study assesses the feasibility of a new volumetric cytometry system for the enumeration of CD34+ cells in apheresis components, peripheral blood, and cord blood samples in routine laboratory work. This system is compared with the following flow cytometry protocols: Milan, ISHAGE, ISHAGE with 7-AAD, and flow-count fluorospheres. STUDY DESIGN AND METHODS Correlation, linearity, and reproducibility studies were performed for the various methods. Clonogenic cultures were performed, as an external control, to assess the correlation between the number of CD34+ cells per microL and the number of colony-forming units per microL. RESULTS The linear regression analysis demonstrated that the five methods were comparable (R2 ranged from 0.86 to 0.96 and slopes were close to 1). The CD34+ assay and the flow-count methods showed poor linearity for CD34+ cell counts below 10 cells per microL (R2 = 0.46 and 0.47). The reproducibility assay for a CD34+ count of 10 cells per microL showed a CV of 12 percent and 25 percent for the Milan and CD34+ assay methods, respectively. The mean CV among all five methods for the 46 evaluated samples was 20 percent. There was a strong correlation between the number of CD34+ cells per microL and colony-forming units per microL in cord blood and apheresis samples (r = 0.71-0.81). CONCLUSION The CD34+ assay is useful in CD34 enumeration in cord blood, leukapheresis samples, and peripheral blood samples and provides comparable results to the Milan, ISHAGE, ISHAGE with 7-AAD, and flow-count methods. Nevertheless, peripheral blood samples with low CD34 absolute counts (below 10 cells/microL) should be analyzed by alternative flow cytometry protocols. Even though the same operator performed the study in a single laboratory, the high inter-method CV suggests that differences in sample preparation and gating strategy are factors that increase variability. Protocols with fewer intermediate steps or fully automated protocols such as the CD34+ assay are expected to reduced intra- and inter-laboratory variability.