Advances in umbilical cord blood transplantation

The first successful cord blood transplant was reported in 1989. In the last sixteen years, there has been a substantial increase in the use of cord blood as an alternative stem cell source for patients without matched related or unrelated bone marrow donors. Approximately 5000 cord blood transplants have been performed worldwide. Recently, the results in adult cord blood transplantation appear promising. In this review, the preclinical background, cord blood banking, and ethical issues will be briefly addressed. Outcome data for both pediatric and adult transplantation will be reviewed, with an emphasis on new strategies for adult cord blood transplantation. New indications for cord blood use outside of hematology/oncology will also be explored.     

脐带血移植的应用进展及脐带血库建设

脐带血(umbilical cord blood)作为公认的造血干细胞重要来源之一,已经被广泛地用于治疗儿童和成人的良恶性血液系统疾病以及中枢神经系统疾病、实体瘤、缺血性下肢血管病和组织再生等。相对于骨髓移植和外周血来源的造血干细胞移植,脐带血移植(UCBT)在细胞收集使用、干细胞增殖能力以及移植物抗宿主反应等方面都具有明显的优势。目前的数据显示,因为HLA配型等原因而无法进行骨髓移植的患者应该尽早进行UCBT。此外,UCBT的增多促进了脐带血库的快速建设。本文针对UCBT和脐带血库的最新进展进行了综述。     

Expanded umbilical cord blood T cells used as donor lymphocyte infusions after umbilical cord blood transplantation

BackgroundUmbilical cord blood (UCB) is an alternative graft source for hematopoietic stem cell transplantation and has been shown to give results comparable to transplantation with other stem cell sources. Donor lymphocyte infusion (DLI) is an effective treatment for relapsed malignancies after hematopoietic stem cell transplantation. However, DLI is not available after UCB transplantation.MethodsIn this study, in vitro–cultured T cells from the UCB graft were explored as an alternative to conventional DLI. The main aim was to study the safety of the cultured UCB T cells used as DLI because such cell preparations have not been used in this context previously. We also assessed potential benefits of the treatment.ResultsThe cultured UCB T cells (UCB DLI) were given to 4 patients with mixed chimerism (n = 2), minimal residual disease (n = 1) and graft failure (n = 1). No adverse reactions were seen at transfusion. Three of the patients did not show any signs of graft-versus-host disease (GVHD) after UCB DLI, but GVHD could not be excluded in the last patient. In the patient with minimal residual disease treated with UCB DLI, the malignant cell clone was detectable shortly before infusion but undetectable at treatment and for 3 months after infusion. In 1 patient with mixed chimerism, the percentage of recipient cells decreased in temporal association with UCB DLI treatment.ConclusionsWe saw no certain adverse effects of treatment with UCB DLI. Events that could indicate possible benefits were seen but with no certain causal association with the treatment.     

Expansion of human cord blood hematopoietic stem cells for transplantation

A recent Science paper reported a purine derivative that expands human cord blood hematopoietic stem cells in culture (Boitano et al., 2010) by antagonizing the aryl hydrocarbon receptor. Major problems need to be overcome before ex vivo HSC expansion can be used clinically.     

Overcoming the barriers to umbilical cord blood transplantation

Umbilical cord blood (UCB) transplantation (UCBT) has seen a marked increase in utilization in recent years, especially in the pediatric population; however, graft failure, delayed engraftment and profound delay in immune reconstitution leads to significant morbidity and mortality in adults. The lack of cells available for post-transplant therapies, such as donor lymphocyte infusions, has also been considered a disadvantage. To overcome the cell–dose barrier, the combination of two UCB units is becoming commonplace in adolescent and adult populations, and is currently being studied in pediatrics as well. In some studies, the use of two UCB units appears to have a positive impact on outcomes; however, engraftment is still suboptimal. A possible additional way to improve outcome and extend applicability of UCBT is via ex vivo expansion. Studies to develop optimal expansion conditions are still in the exploratory phase; however, recent studies suggest expanded UCB is safe and can improve outcomes. The ability to transplant across HLA disparities, rapid procurement time and decreased graft-versus-host disease (GvHD) seen with UCBT makes it a promising stem cell source and, while barriers exist, consistent progress is being made to overcome them.     

Results of unrelated umbilical cord blood hematopoietic stem cell transplantation

The number of umbilical cord blood transplants is increasing worldwide. The purpose of Eurocord is to evaluate the results and to compare the outcome of umbilical cord blood transplants with allogeneic bone marrow transplants. Data have been reported to Eurocord by multiple transplant centers. Close links have been established with the cord blood banks through Netcord. Bone marrow transplant data have been provided by transplant centers and also through the European Group for Blood and Marrow Transplantation (EBMT) and International Bone Marrow Transplant Registries (IBMTR). Eurocord has analyzed the outcome of unrelated umbilical cord blood transplants from 121 transplant centers and 29 countries. The results showed that survival with unrelated mismatched umbilical cord blood transplants was comparable to that with unrelated bone marrow transplants. Engraftment with cord blood was delayed, resulting in an increased incidence of early transplant complications. The incidence of acute and chronic graft-vs.-host disease was reduced with cord blood grafts even in human leukocyte antigen (HLA)-mismatched transplants and in adults. In patients with leukemia, the rate of relapse was similar to the rate of relapse after bone marrow transplant. The overall event-free survival with umbilical cord blood transplantation was not statistically different when compared to bone marrow transplants. This large registry study confirms the potential benefit of using umbilical cord blood hematopoietic stem cells for allogeneic transplants.     

Banking and transplantation of umbilical cord blood in Guangzhou, China

BACKGROUND: Umbilical cord blood (UCB) is an alternative source of hematopoietic stem cells (HSC) for transplantation of patients with hematologic malignancies or hereditary diseases. METHODS: We developed a provincial UCB bank in Guangzhou, China, using good manufacturing practices and standard operating procedures to address donor eligibility, collection, characterization, processing, storage and release from quarantine. The banking activities were analyzed. RESULTS: From June 1998 to May 2005, 8623 UCB units of Han ethnic origin were collected; 4147 (48.1%) were stored, while 4476 (51.9%) were discarded as a result of pre-determined exclusion criteria. A median volume of 95.5 mL (range 60-227.7) and 1.2 x 10(9) (0.8-9.3) nucleated cells were collected. The cell viability was 97.8% (90-100%). The CD34+ cell count of 3691 (89.0%) UCB units was 5.2 x 10(6) (0.3-131.6) and clonogenic assays of 4036 (97.3%) UCB units demonstrated 9.8 x 10(5) (0.04-135.8) CFU-GM, 0.3 x 10(5) (0.0-18.6) CFU-GEMM and 8.8 x 10(5) (0.0-74.2) BFU-E. A total of 0.4% (15/3863) UCB derived from babies known to have health problems at age 6 months was discarded. Up to May 2005, 151 units were issued for transplantation to 127 patients [90 (70.9%) children and 37 (29.1%) adults]. The infused nucleated cells in unrelated single-unit recipients were 3.4 x 10(7)/kg (1.7-14.9) for adults (n=19) and 5.7 x 10(7)/kg (2.0-20.5) for children (n=71), respectively. The numbers of days for the engraftment of neutrophils among 65 children and 22 adults were 17 (7-41) and 20 (10-42), respectively. DISCUSSION: Data of this study show that stringent procedures and comprehensive policies are requisite for pursuing the banking and release of quality UCB for successful transplantation.     

History of the clinical use of umbilical cord blood hematopoietic cells

The first cord blood (CB) transplant was performed in 1988 in a patient with Fanconi anemia. The donor was his HLA-identical sister who was known by pre-natal diagnosis to be HLA identical and not affected by the Fanconi mutation. The CB was collected and cryopreserved at birth. The transplant was successful without GvHD and the patient is currently alive and free of disease more than 15 years after transplant, with full hematologic and immunologic donor reconstitution. At the time of the first transplant, little was known about the biologic properties of CB cells and it was thanks to the pioneering work of H. E. Broxmeyer and E. A. Boyse, who studied the progenitor cell content of CB, and of A. D. Auerbach, who realized the pre-natal diagnosis of Fanconi anemia, that this transplant was possible. Since this first transplant, many questions have been answered but others are still open for further research. For example: would a single CB unit contain enough stem cells to permanently engraft children and adults? Would maternal cell contamination in fetal blood engraft and give severe GvHD? What are the immunologic properties of CB cells? How does it interfere with GvHD, GvL and immune reconstitution? Is the immune immaturity of CB lymphocytes able to overcome the HLA barrier and authorize HLA-mismatched transplants? Is it possible to establish CB banks for unrelated and related transplants? What would be the criteria for collection, quality control and cryopreservation?     

Banking strategies for improving the hematopoietic stem cell content of umbilical cord blood units for transplantation

Umbilical cord blood (UCB) has become an alternative source of hematopoietic progenitors (HSC) for transplantation. Although most CB transplants have been performed in children, unrelated donor-cord blood transplants in adults have been growing steadily in recent years. HSC content of CB units influence significantly the transplantation outcome, as shown by many clinical studies. UCB banks are fundamental to support this increasing clinical activity and one of their main goals must be to store good quality units. Strategies for increasing HSC content of UCB units are reviewed and also its influence on transplantation outcome. Our bank selected the UCB units for cryopreservation on the basis of their total nucleated cells (TNC) and CD34(+) cells content. We also reviewed the results of our UCB bank program.     

人脐带间充质干细胞移植治疗脊髓损伤的研究进展

脊髓损伤（SCI）由于复杂病理生理和神经修复再生困难,至今仍旧是难以攻克的医学难题,而干细胞因其神经再生和神经保护特性被认为是治疗SCI最有希望的方法。其中人脐带间充质干细胞（HUC-MSCs）近年培养分化方法不断改进、神经修复机制初步阐明,联合移植等综合治疗方案也不断实践,使HUC-MSCs移植治疗效果提高。另外关于HUC-MSCs治疗SCI的临床试验逐渐开展,术后患者神经功能恢复改善且无严重并发症出现,表明干细胞移植应用于人体是安全有效的。本文就HUC-MSCs治疗SCI的研究状况及进展进行综述。     

Preclinical transplantation and safety of HS/PCs expanded from human umbilical cord blood

AIM: To expand hematopoietic/progenitor stem cells (HS/PCs) from umbilical cord blood (UCB) and prepare the HS/PC product, and analyze preclinical transplantation and safety of HS/PC product. METHODS: Human bone marrow-derived mesenchymal stem cells (MSCs) were used as feeder cells to expand HS/PCs from UCB in a serum-free culture system. The proliferation potential of HS/PCs was analyzed. The expanded HS/PCs were suspended in the L-15 medium to prepare the HS/PC product. The contamination of bacteria, fungi and mycoplasmas, the infection of exogenous virus, the concentration of bacterial endotoxin, and the SCF residual in HS/PC product were determined. Finally, cells from the HS/PC product with or without bone marrow-derived mesenchymal stem cells (BM-MSCs) were transplanted into the irradiated NOD/SCID mice to determine the in vivo engraftment potential. RESULTS: After co-culture for 10 d, the total nuclear cells (TNCs) increased 125-fold, and CD34 + cells increased 43-fold. The granulocyte-macrophage colonyforming cells (GM-CFCs) and erythroid colony-forming cells (E-CFCs) increased 3.3and 4.7-fold respectively. The expanded cells were collected and prepared as the expanded product of HS/PCs by re-suspending cells in L-15 medium. For preclinical safety, the HS/PC product was analysed for contamination by bacteria, fungi and mycoplasmas, the bacterial endotoxin concentration and the SCF content. The results showed that the HS/PC product contained no bacteria, fungi or mycoplasmas. The bacterial endotoxin concentration was less than the detection limit of 6 EU/mL, and residual SCF was 75 pg/mL. Based on clinical safety, the HS/PC product was qualified for clinical transplantation. Finally, the HS/PC product was transplanted the irradiated mice where it resulted in rapid engraftment of hematopoietic cells. CONCLUSION: HSPC product prepared from UCB in the serum-free culture system with hMSCs as feeder cells should be clinically safe and effective for clinical transplantation.     

Improving clinical outcomes using adoptively transferred immune cells from umbilical cord blood

Because of the necessary immunodepletion prior to cord blood transplantation as well as the immaturity of cord blood immune cells, recipients experience a high incidence of viral infection in addition to complications observed after hematopoietic stem cell transplantation, such as relapse and graft-versus-host disease. We describe current immunotherapeutic approaches to treating these complications, including the generation of antigen-specific T cells from cord blood, redirecting cord blood T cells using chimeric antigen receptors, and generating cord blood-derived natural killer cells and regulatory T cells.     

Influence of volume reduction and cryopreservation methodologies on quality of thawed umbilical cord blood units for transplantation

Introduction

Although there is considerable variability in methodology among umbilical cord blood banks, their common goal is to achieve optimal product quality for transplantation. Cryopreservation is a critical issue for a long-term maintenance of cord blood viability and colony-forming capacities.

Materials and methods

We designed a prospective study to compare controlled (CRF) vs. non-controlled freezing (URF) of volume-reduced cord blood units. In addition, the influence of hydroxy ethyl starch (HES) on cryopreservation was also assayed. To assess the efficiency of protocols used, cell recoveries were measured and the presence of hematopoietic colony-forming units was quantified.

Results

In the study phase, we observed similar CB haematopoietc recoveries for CRF and URF strategies, except for TNC recovery that was better for HES volume reduced CB units in the URF group. When we analysed the data of routine processed CB units in samples from satellite cryovials, we found better BFU-E, CFU-GM, CFU-GEMM and CFU recoveries for those units processed with HES than without HES, in an URF manner.

Conclusions

URF of CB units is a cryopreservation procedure that allows similar hematopoietic progenitor recoveries than CRF with programmed devices. However, our study suggests that those banks that cryopreserve CB units in a URF manner should use HES for volume reduction. On the other hand, for CRF cryopreservation methodology volume reduction with and without HES are equally useful.     

Ex vivo expansion of umbilical cord blood

The efficacy of cord blood (CB) transplantation is limited by the low cell dose available. Low cell doses at transplant are correlated with delayed engraftment, prolonged neutropenia and thrombocytopenia and elevated risk of graft failure. To potentially improve the efficacy of CB transplantation, approaches have been taken to increase the cell dose available. One approach is the transplantation of multiple cord units, another the use of ex vivo expansion. Evidence for a functional and phenotypic heterogeneity exists within the HSC population and one concern associated with ex vivo expansion is that the expansion of lower 'quality' hematopoietic progenitor cells (HPC) occurs at the expense of higher 'quality' HPC, thereby impacting the reserve of the graft. There is evidence that this is a valid concern while other evidence suggests that higher quality HPC are preserved and not exhausted. Currently, ex vivo expansion processes include: (1) liquid expansion: CD34+ or CD133+ cells are selected and cultured in medium containing factors targeting the proliferation and self-renewal of primitive hematopoietic progenitors; (2) co-culture expansion: unmanipulated CB cells are cultured with stromal components of the hematopoietic microenvironment, specifically mesenchymal stem cells (MSC), in medium containing growth factors; and (3) continuous perfusion: CB HPC are cultured with growth factors in 'bioreactors' rather than in static cultures. These approaches are discussed. Ultimately, the goal of ex vivo expansion is to increase the available dose of the CB cells responsible for successful engraftment, thereby reducing the time to engraftment and reducing the risk of graft failure.     

脐血单个核细胞移植对帕金森病的临床疗效研究

目的观察经寰枕间隙侧方穿刺术移植人脐血单个核细胞（hUCB-MNCs）治疗帕金森病（PD）的临床疗效。 方法选取聊城市人民医院神经内科经寰枕间隙侧方穿刺术移植hUCB-MNCs治疗的31例PD患者，于治疗前及治疗后1、3、6、12个月，采用统一帕金森评估量表（UPDRS）第Ⅱ部分、第Ⅲ部分和帕金森非运动症状评价量表（NMSS）、匹兹堡睡眠质量指数量表（PSOI）对患者进行评分，并记录左旋多巴等效剂量（LED）。采用重复测量资料方差分析对治疗前后多个时间点的评分及左旋多巴等效剂量进行比较，两两比较采用Bonferroni检验。 结果（1）与治疗前比较，治疗后3、6、12个月UPDRS Ⅱ评分[（17.75±6.81）分比（13.67±5.62）分、（12.54±4.39）分、（10.41±4.31）分]均降低；治疗后3、6、12个月UPDRS Ⅲ评分[（28.53±14.75）分比（21.65±10.11）分、（19.37±9.26）分、（16.12±7.44）分]亦均降低，差异有统计学意义（P < 0.05）。（2）与治疗前比较，治疗后1、3、6、12个月NMSS评分[（58.94±35.74）分比（50.27±31.06）分、（41.38±28.25）分、（38.42±25.73）分、（36.15±24.56）分]均降低，差异有统计学意义（P < 0.05）。PSOI评分亦有相同变化趋势。（3）与治疗前比较，治疗后6、12个月LED[（629.57±205.33）mg/d比（435.54±160.62）mg/d、（300.71±135.83） mg/ d]下降，差异有统计学意义（P < 0.05）。 结论经寰枕间隙侧方穿刺术移植hUCB-MNCs治疗能改善PD患者的运动及非运动症状，延缓病情的进展。     

脐血干细胞移植治疗失代偿期肝硬化的临床疗效

目的:探讨人脐血干细胞(umbilical cord blood stem cell,UCBSC)外周静脉移植治疗失代偿期肝硬化的临床疗效及可行性.方法:20例失代偿期肝硬化患者采用人UCBSC外周静脉移植治疗,治疗后定期观察患者血清转氨酶(ALT、AST)、总胆红素(TBIL)、白蛋白(ALB)、凝血酶原时间(PT)和纤维蛋白原(FIB)水平变化,并观察患者临床症状及体征的改善情况及不良反应.结果:UCBSC移植治疗后2周,各项肝功能指标较治疗前无显著性差异(P＞0.05);治疗后4周,除ALT和AST有所改善外(P＜0.05),其余指标无明显改善;治疗后8周各项肝功能指标均有改善(P＜0.05),12周有显著性改善(P＜0.01).治疗后4周大多数患者的临床症状有明显改善,腹水减少和双下肢浮肿减轻15例(75.0%)、乏力好转16例(80%)、食欲改善13例(65%).UCBSC移植后12周患者总体生存率为90%,其中2例患者分别在UCBSC静脉移植后4周和8周因为肝性昏迷和自发性细菌性腹膜炎而死亡.所有患者均未发现与细胞移植相关的副作用.结论:UCBSC外周静脉移植是治疗失代偿期肝硬化一种安全有效的方法,短期内可以改善失代偿期肝硬化患者肝功能及临床症状,是一种值得推荐的治疗方法.     

Mesenchymal stromal cells from umbilical cord blood

Mesenchymal Stromal Cells (MSC) are key candidates for cellular therapies. Although most therapeutic applications have focused on adult bone marrow derived MSC, increasing evidence suggests that MSC are present within a wide range of tissues. Umbilical cord blood (CB) has been proven to be a valuable source of hematopoietic stem cells, but its therapeutic potential extends beyond the hematopoietic component suggesting regenerative potential in solid organs as well. There is evidence that other stem or progenitor populations, such as MSC, exist in CB which might be responsible for these effects. Many different stem and progenitor cell populations have been postulated with potential ranging from embryonic like to lineage-committed progenitor cells. Based on the confusing data, this review focuses on a human CB derived, plastic adherent fibroblastoid population expressing similar characteristics to bone marrow derived MSC. It concentrates especially on concepts of isolation and expansion, comparing the phenotype with bone marrow derived MSC, describing the differentiation capacity and finally in the last the therapeutic potential with regard to regenerative medicine, stromal support, immune modulation and gene therapy.