Update on umbilical cord blood transplantation

Single laboratory evaluation of umbilical cord blood units processing methodologies for banking

OBJECTIVE

To compare the efficiency of 3 different processing methods (Sepax, AutoXpress [AXP], and manual processing with hydroxyethyl starch [HES] sedimentation) used at Stemlab during a 10-year period.

METHODS

Historical data were compiled and the analytical results obtained for the 3 different methods were compared.

RESULTS

The manual processing (HES) method yielded the highest level of total nucleated cell recovery after processing, and the AXP system yielded the highest CD34+ cell number. The red blood cell reduction was also significantly higher with the HES method. Also, HES showed comparable results to Toticyte technology for umbilical cord blood (UCB) processing.

CONCLUSION

These results show that the HES method is as effective as automated technologies for UCB volume reduction; hence, it is a suitable methodology for private and public UCB banks. The HES method also proved to be superior to Toticyte technology for medical applications, with higher recovery yields of total nucleated cells after thawing and equivalent CD34+ cell recovery and functionality.

The Present Condition of Sickle Cell Disease: An Overview of Stem Cell Transplantation as a Cure

Treatment of sickle cell disease (SCD) remains largely palliative. While it can enhance living standards, persons having SCD still suffer from extreme sickling crises, end-organ destruction, and reduced life expectancy. Increasing research has resulted in the recognition and advancement of stem cell transplantation and gene therapy as possible solutions for SCDs. However, there have been various factors that have hindered their clinical application. The more advantageous of the two, stem cell transplantation, is constrained by a small donor pool, transplant difficulties, and eligibility requirements. The current article reviewed the literature on SCDs, current treatment options, and more particularly the progress of stem cell transplants. It outlined various challenges of stem cell transplant and proposed ways to increase the donor pool using alternative strategies and modifications of regimen conditioning with minimal transplant-related toxicities and associated complications.

Outcomes of Children Who Present to the Emergency Department After Hematopoietic Cell Transplantation

OBJECTIVES

Our primary objective was to describe emergency department (ED) presentation, treatment, and outcomes for children after hematopoietic cell transplantation (HCT). Our secondary objective was to identify factors associated with serious infection in this population.

METHODS

This is a retrospective review of HCT patients who presented to our university children's hospital ED from January 1, 2011, to June 30, 2013. Emergency department presentation, treatment, and outcomes were described. Descriptive statistics were used to compare children with definite serious infection with those without serious infection. Multiple binary logistic regression was performed for risk factors associated with definite serious infection.

RESULTS

Fifty-four HCT patients (132 encounters) presented to our ED. Most were transplanted for a malignant (46%) or metabolic (36%) diagnosis and were recipients of bone marrow (51%) or umbilical cord blood (45%). Fever was the most common complaint (25%). Emergency department laboratory (64%) or imaging (58%) studies were frequently obtained. Admission was common (n = 70/132, 53%), with 79% (n = 55) of admissions to intensive care or bone marrow transplant units. Thirty-five encounters had definite serious infection, 5 had probable serious infection, and 92 had no serious infection. Fever (P < 0.001) and high-risk white blood cell (WBC) count of less than 5 or greater than 15 k/μL (P < 0.001) were associated with definite serious infection. Fever (odds ratio = 8.84, 95% confidence interval = 2.92-26.73) and high-risk WBC (odds ratio = 6.67, 95% confidence interval = 2.24-19.89) remained significantly associated with definite serious infection in our regression model.

CONCLUSIONS

Children presenting to the ED after HCT require extensive support and resources, with more than half requiring admission. Fever and high-risk WBC are associated with serious infection.

Optimal umbilical cord blood collection, processing and cryopreservation methods for sustained public cord blood banking

BACKGROUND AIMS

Umbilical cord blood is an established source of stem cells in patients with hematologic malignancies who do not have HLA-compatible matched related or unrelated donors. The success of an umbilical cord blood transplant depends on the dose of total nucleated and CD34+ cells infused. Therefore, collecting, banking and listing high-quality cord blood units with high total nucleated and CD34+ cell dose are essential.

METHODS

Here the authors describe their cord blood bank's novel collection technique, which involves both in utero and ex utero collection of a single cord blood unit. The authors also evaluated maternal, neonatal and collection parameters that may impact the cell dose.

RESULTS

Maternal gestational age and race, and neonatal weight and sex correlated with the total nucleated cell dose.

CONCLUSIONS

The optimized collection of umbilical cord blood is critical for its use as a source of stem cells for transplantation.

Potentiation of cord blood cell therapy with erythropoietin for children with CP: a 2 × 2 factorial randomized placebo-controlled trial

Background

Concomitant administration of allogeneic umbilical cord blood (UCB) infusion and erythropoietin (EPO) showed therapeutic efficacy in children with cerebral palsy (CP). However, no clinical studies have investigated the effects of UCB and EPO combination therapy using a 2 × 2 four-arm factorial blinded design with four arms. This randomized placebo-controlled trial aimed to identify the synergistic and individual efficacies of UCB cell and EPO for the treatment of CP.

Methods

Children diagnosed with CP were randomly segregated into four groups: (A) UCB+EPO, (B) UCB+placebo EPO, (C) placebo UCB+EPO, and (D) placebo UCB+placebo EPO. Based on the UCB unit selection criteria of matching for ≥ 4/6 of human leukocyte antigen (HLA)-A, -B, and DRB1 and total nucleated cell (TNC) number of ≥ 3 × 10⁷/kg, allogeneic UCB was intravenously infused and 500 IU/kg human recombinant EPO was administered six times. Functional measurements, brain imaging studies, and electroencephalography were performed from baseline until 12 months post-treatment. Furthermore, adverse events were closely monitored.

Results

Eighty-eight of 92 children enrolled (3.05 ± 1.22 years) completed the study. Change in gross motor performance measure (GMPM) was greater in group A than in group D at 1 month (△2.30 vs. △0.71, P = 0.025) and 12 months (△6.85 vs. △2.34, P = 0.018) post-treatment. GMPM change ratios were calculated to adjust motor function at the baseline. Group A showed a larger improvement in the GMPM change ratio at 1 month and 12 months post-treatment than group D. At 12 months post-treatment, the GMPM change ratios were in the order of groups A, B, C, and D. These results indicate synergistic effect of UCB and EPO combination better than each single therapy. In diffusion tensor imaging, the change ratio of fractional anisotropy at spinothalamic radiation was higher in group A than group D in subgroup of age ≥ 3 years. Additionally, higher TNC and more HLA-matched UCB units led to better gross motor outcomes in group A. Adverse events remained unchanged upon UCB or EPO administration.

Conclusions

These results indicate that the efficacy of allogeneic UCB cell could be potentiated by EPO for neurological recovery in children with CP without harmful effects.

Trial registration

ClinicalTrials.gov, NCT01991145, registered 25 November 2013.

Regenerative Cell-Based Therapies: Cutting Edge, Bleeding Edge, and Off the Edge

With the emergence of cell-based therapies as viable treatment options readily accessible to patients, the scientific community and public have raised concerns regarding consumer accessibility and regulation enforcement. Opposing viewpoints regarding regulation have emerged, and efforts to maintain the balance between promoting scientific innovation and ensuring public safety has proved challenging. To further complicate matters, there is contradictory information regarding the clinical safety and efficacy of cell-based treatments. Herein, we outline the FDA's regulatory framework for cell-based therapies and describe what we term the cutting edge, bleeding edge, and off the edge interventions. We conclude with a new classification system for regenerative cell-based therapies intended to further aid in delineating between the clinically and scientifically sound therapies to those that compel further scientific investigation.

Mevalonic aciduria: Does stem cell transplant fully cure disease?

MA is a rare, autosomal recessive disorder characterized by episodes of inflammation and periodic fevers. In its most severe form, it can result in facial dysmorphism, growth inhibition, ataxia, liver dysfunction, intellectual disability, and at times can be fatal. A number of case reports exist stating that SCT is curative in these patients. We present the case of a patient diagnosed with MA at birth, who underwent SCT at the age of 14 months with intent to cure. She achieved complete engraftment and urine mevalonate became undetectable. However, 18 months following transplant, she developed frequent episodes of fevers, rashes, arthritis, and a rising urinary mevalonate. She was subsequently diagnosed with relapse. She now requires treatment with steroids and canakinumab to manage her disease. This case is the first report of disease relapse following transplant for MA. It runs contrary to prior reports that SCT is fully curative of MA and suggests that transplant may instead provide a means of decreasing disease severity without entirely eradicating the condition.

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.

Single-cell transcriptomic landscape of nucleated cells in umbilical cord blood

BACKGROUND

For both pediatric and adult patients, umbilical cord blood (UCB) transplant is a therapeutic option for a variety of hematologic diseases, such as blood cancers, myeloproliferative disorders, genetic diseases, and metabolic disorders. However, the level of cellular heterogeneity and diversity of nucleated cells in UCB has not yet been assessed in an unbiased and systemic fashion. In the present study, nucleated cells from UCB were subjected to single-cell RNA sequencing to simultaneously profile the gene expression signatures of thousands of cells, generating a rich resource for further functional studies. Here, we report the transcriptomes of 17,637 UCB cells, covering 12 major cell types, many of which can be further divided into distinct subpopulations.

RESULTS

Pseudotemporal ordering of nucleated red blood cells identifies wave-like activation and suppression of transcription regulators, leading to a polarized cellular state, which may reflect nucleated red blood cell maturation. Progenitor cells in UCB also comprise 2 subpopulations with activation of divergent transcription programs, leading to specific cell fate commitment. Detailed profiling of cytotoxic cell populations unveiled granzymes B and K signatures in natural killer and natural killer T-cell types in UCB.

CONCLUSIONS

Taken together, our data form a comprehensive single-cell transcriptomic landscape that reveals previously unrecognized cell types, pathways, and mechanisms of gene expression regulation. These data may contribute to the efficacy and outcome of UCB transplant, broadening the scope of research and clinical innovations.

Diversity of dendritic cells generated from umbilical cord or adult peripheral blood precursors

Following the discovery of methods to generate large numbers of specific dendritic cells (DCs) ex vivo, the possibility of exploiting these cells in immunotherapeutic strategies will become a reality. It seems to be rationally to analyse the influence of the precursor source for further features and applications. For the needs of the given project DCs were derived from precursors derived from adult peripheral blood (APB) and umbilical cord blood (UCB). During some expansions of UCB CD34⁺ cells were separated giving non-adherent DCs (NA-DCs) or adherent DCs (A-DCs), whereas DCs derived from UCB precursors without separation gave rise to All-DCs. DC subpopulations were stimulated by lipopolysaccharides (LPS) or interferon-γ (IFN-γ), and afterwards the morphology, phenotype, and stimulatory properties were analysed. Our findings demonstrated that DCs generated from APB and UCB precursors were not equivalent and exhibited opposite features when expanded in comparable conditions. Additionally, all three subpopulations of UCB-derived DCs presented functional dissimilarities. Based on our results we concluded that the precursor source and the composition of media must be considered as crucial to the success of potential therapeutic application.

Sickle Cell Disease: Advances in Treatment

BACKGROUND

Sickle cell disease causes significant morbidity and mortality and affects the economic and healthcare status of many countries. Yet historically, the disease has not had commensurate outlays of funds that have been aimed at research and development of drugs and treatment procedures for other diseases.

METHODS

This review examines several treatment modalities and new drugs developed since the late 1990s that have been used to improve outcomes for patients with sickle cell disease.

RESULTS

Targeted therapies based upon the pathophysiologic mechanisms of sickle cell disease that result in organ dysfunction and painful episodes include hydroxyurea, L-glutamine, crizanlizumab, and other drugs that are currently on the market or are on the verge of becoming available. These agents have the potential to improve survival and quality of life for individuals with sickle cell disease. Also discussed is stem cell transplantation that, to date, is the only curative approach for this disease, as well as the current status of gene therapy.

CONCLUSION

These examples demonstrate how the current knowledge of sickle cell disease pathophysiology and treatment approaches intersect. Although interest in sickle cell research has blossomed, many more clinical trials need to be initiated and subjected to more strenuous examination and analysis than have been used in the past.

Cellular transplant therapies for globoid cell leukodystrophy: Preclinical and clinical observations

Globoid cell leukodystrophy (GLD) is a progressive neurodegenerative disorder caused by the deficiency of galactocerebrosidase (GALC), resulting in accumulation of toxic metabolites in neural tissues. Clinically variable based on age of onset, infantile GLD is generally a rapidly fatal syndrome of progressive neurologic and cognitive decline, whereas later-onset GLD has a more indolent, protracted clinical course. Animal models, particularly the twitcher mouse, have allowed investigation of both the pathophysiology of and the potential treatment modalities for GLD. Cellular therapy for GLD, notably hematopoietic cell transplantation (HCT; transplantation of bone marrow, peripheral blood stem cells, or umbilical cord blood cells) from a normal related or unrelated allogeneic donor provides a self-renewing source of GALC in donor-derived cells. The only currently available treatment option in human GLD, allogeneic HCT, can slow the progression of the disease and improve survival, especially when performed in presymptomatic infants. Because persistent neurologic dysfunction still occurs after HCT in GLD, preclinical studies are evaluating combinations of HCT with other treatment modalities. © 2016 Wiley Periodicals, Inc.

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.

Transient Tcf3 Gene Repression by TALE-Transcription Factor Targeting

Transplantation of hematopoietic stem and progenitor cells (HSCs) i.e., self-renewing cells that retain multipotentiality, is now a widely performed therapy for many hematopoietic diseases. However, these cells are present in low number and are subject to replicative senescence after extraction; thus, the acquisition of sufficient numbers of cells for transplantation requires donors able to provide repetitive blood samples and/or methods of expanding cell numbers without disturbing cell multipotentiality. Previous studies have shown that HSCs maintain their multipotentiality and self-renewal activity if TCF3 transcription function is blocked under B cell differentiating conditions. Taking advantage of this finding to devise a new approach to HSC expansion in vitro, we constructed an episomal expression vector that specifically targets and transiently represses the TCF3 gene. This consisted of a vector encoding a transcription activator-like effector (TALE) fused to a Krüppel-associated box (KRAB) repressor. We showed that this TALE-KRAB vector repressed expression of an exogenous reporter gene in HEK293 and COS-7 cell lines and, more importantly, efficiently repressed endogenous TCF3 in a human B lymphoma cell line. These findings suggest that this vector can be used to maintain multipotentiality in HSC being subjected to a long-term expansion regimen prior to transplantation.

Stem cells therapy in cerebral palsy: A systematic review

The aim of this study was to systematically present the best available stem cell therapies for children with cerebral palsy (CP). The databases Medline, PubMed, EMBASE, and the Cochrane Controlled Trials Register for RCTs were searched for studies published from 1967 to August 2015. Systematic reviews, randomised controlled trials (RCTs), controlled trials, uncontrolled trials, cohort studies, open-label studies, and a meta-analysis were analysed. Of 360 articles, seven fulfilled the inclusion criteria: one RCT and six were open-label trials. In these studies, one application of stem cells for children with CP was typical, and the total number of cells administered to patients ranged from 10(6) to 10(8)/kg. Different routes of cell delivery were used, though in most studies motor development was applied as an indicator of primary outcomes. In three articles, neuroimaging studies were also implemented to confirm the efficacy of the therapies. Observation periods varied from 3months to 5years, and patients' tolerance of the therapy was generally good. Stem cell therapy may improve some symptoms in patients with CP, though larger studies are needed to examine the impact of stem cell therapy upon CP.

Alternative donor allogeneic hematopoietic cell transplantation for hemoglobinopathies

Allogeneic hematopoietic stem cell transplantation (HSCT) offers a curative therapy for patients with hemoglobinopathies, mainly severe sickle cell disease (SCD) and thalassemia (TM). However, the applicability of HSCT has been limited mainly by donor availability, with a less than 25%-30% of eligible patients having human leukocyte antigen (HLA)-matched sibling donors. Previous outcomes using alternate donor options have been markedly inferior due to increased regimen-related toxicity, transplant-related mortality, graft failure, and graft-versus-host disease (GVHD). Advances in transplant technology, including high-resolution HLA typing, improved GVHD prophylactic approaches with tolerance induction, and better supportive care over the last decade, are addressing these historical challenges, resulting in increasing donor options. Herein, we review alternate donor HSCT approaches for severe SCD and TM using unrelated donors, umbilical cord blood units, or related haploidentical donors. Though this is an emerging field, early results are promising and in selected patients, this may be the preferred option to mitigate against the age-related morbidity and early mortality associated with these disorders.

Factors That Influence a Mother's Willingness to Preserve Umbilical Cord Blood: A Survey of 5120 Chinese Mothers

BACKGROUND

Umbilical Cord blood (UCB), which contains a substantive number of stem cells, could be widely used in transplants to treat a variety of oncologic, genetic, hematologic, and immunodeficiency disorders. However, only a small portion of mothers preserve or donate their UCB in China. The limited availability of UCB has hampered stem cell research and therapy nowadays. To date, no systemic investigations regarding factors that influence a mother's willingness to preserve UCB have been performed in China. In the current study, we are trying to determine those factors which will provide useful information for national health policy development and will raise awareness of the importance of UCB preservation.

METHODS

During 2011 to 2013, 5120 mothers with the average age of 26.1±8.4 years were included in this study. Those mothers participated in a standardized survey. The information gathered consisted of delivery time, occupation, level of education, knowledge of preservation of UCB, willingness to store UCB, and related concerns. The results have been analyzed with SPSS 16.0.

RESULTS

The results showed that first-time mothers showed a greater willingness to preserve their UCB (73.3%) compared to those having their second (48.9%) or third child (40.3%). Mothers who were employed at Government Agencies and Organizations were more willing to preserve their UCB (87.3%) than those employed at factories (62.0%), and those who were unemployed (27.3%). Mothers holding master's or college degrees were more willing to preserve their UCB (72.5% and 71.1%, respectively) than mothers with high school diplomas (48.7%) or those who only went to preliminary school or middle school (40.7%). The two strongest factors that influenced an unwillingness to preserve UCB were the high cost and concerns regarding the safety of the preservation.

CONCLUSIONS

The results showed that mothers with higher education or those having better occupations are more likely to preserve their UCB in China. These mothers have related knowledge and understand the importance of the preservation and they could more readily afford the relatively high cost. The government, clinicians and UCB banks should combine efforts to take measures, such as increasing public knowledge of the importance of UCB preservation and decreasing the high cost for its storage will most likely increase the frequency of UCB preservation which will further benefit stem cell research and therapy.

Safety of Allogeneic Umbilical Cord Blood Stem Cells Therapy in Patients with Severe Cerebral Palsy: A Retrospective Study

This retrospective study aimed to assess the safety of patients with severe cerebral palsy (CP), who received allogeneic umbilical cord blood stem cells (UCBSCs) treatment from August 2009 to December 2012 in Guangdong Provincial Hospital of Chinese Medicine. A total of 47 patients with average age of 5.85 ± 6.12 years were evaluated in this study. There was no significant association with allogeneic UCBSCs treatments found in the data of the laboratory index . No casualties occurred. Some adverse events during treatments were found in 26 (55.3%) patients, including fever (42.6%) and vomiting (21.2%). Intrathecal infusion and the ages at the initiation of treatment (≤10 years old) were risk factors for the occurrence of adverse events by logistic regression analysis. However, all adverse events disappeared after symptomatic treatment. No treatment related serious adverse events were found in follow-up visits within 6 months. In conclusion, allogeneic UCBSCs treatment was relatively safe for severe CP patients.

Unique properties of cluster of differentiation 93 in the umbilical cord blood of neonates

It has previously been reported by these authors that cluster of differentiation (CD) 93 is co-expressed on naive T-lymphocytes (CD4(+) CD45RA(+) cells) in neonatal umbilical cord blood cells (UCBCs) but not on normal adult peripheral blood cells (PBCs). In this study, expression of CD93 on other lymphocyte subsets and the concentration of soluble formed CD93 (sCD93) in serum or culture supernatants from neonatal umbilical cord blood (UCB) was examined. It was found that CD93 is also co-expressed on CD2(+) , CD16(+) , CD56(+) or CD25(+) cells in the lymphocyte population of neonatal UCBCs, but not on normal adult PBCs. The concentrations of sCD93 in serum and culture supernatants from neonatal UCB were significantly greater than those from normal adult peripheral blood. The concentrations of sCD93 in culture supernatants from neonatal UCBCs and normal adult PBCs treated with phorbol 12-myristate 13-acetate (PMA) were significantly enhanced compared with those without PMA treatment. The degree of enhancement of sCD93 by PMA in culture supernatants from neonatal UCBCs was significantly greater than that of normal adult PBCs and enhancement of sCD93 by PMA in the culture supernatants from neonatal UCBCs and normal adult PBCs was significantly suppressed by PKC inhibitor. Interestingly, the high concentration of serum sCD93 in neonates was significantly decreased in sera from infants at 1 month after birth. Expression of CD93 on the lymphocyte population of PBCs from infants at 1 month after birth was also significantly decreased, compared with that for neonatal UCBCs. These findings indicate that CD93 in neonatal UCB has unique properties as an immunological biomarker.

Proliferation extent of CD34+ cells as a key parameter to maximize megakaryocytic differentiation of umbilical cord blood-derived hematopoietic stem/progenitor cells in a two-stage culture protocol

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A two-stage protocol established aiming at effective Mk differentiation of UCB CD34⁺-enriched cells.

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Proliferation extent of CD34⁺ cells during expansion identified as a key parameter to maximize Mk differentiation.

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Morphological analysis demonstrated the characteristic features of ex-vivo generated Mks and platelet-like particles.

Co-infusion of ex-vivo generated megakaryocytic progenitors with hematopoietic stem/progenitor cells (HSC/HPC) may contribute to a faster platelet recovery upon umbilical cord blood (UCB) transplantation. A two stage protocol containing cell expansion and megakaryocyte (Mk) differentiation was established using human UCB CD34⁺-enriched cells. The expansion stage used a pre-established protocol supported by a human bone marrow mesenchymal stem cells (MSC) feeder layer and the differentiation stage used TPO (100 ng/mL) and IL-3 (10 ng/mL). 18% of culture-derived Mks had higher DNA content (>4 N) and were able to produce platelet-like particles. The proliferation extent of CD34⁺ cells obtained in the expansion stage (FI-CD34⁺), rather than expansion duration, determined as a key parameter for efficient megakaryocytic differentiation. A maximum efficiency yield (EY) of 48 ± 7.7 Mks/input CD34⁺ cells was obtained for a FI-CD34⁺ of 17 ± 2.5, where a higher FI-CD34⁺ of 42 ± 13 resulted in a less efficient megakaryocytic differentiation (EY of 22 ± 6.7 and 19 ± 4.6 %CD41).

Implication of cord blood for cell-based therapy in refractory childhood diseases

Since cord blood (CB) contains hematopoietic stem cells as well as a mixture of multipotent stem cells, CB has the ability to give rise to hematopoietic, epithelial, endothelial and neural tissues. Recently, the application of cell-based therapy using CB has expanded its clinical utility, particularly, by using autologous CB in children with refractory diseases. This review focuses clinical and pre-clinical application of CB cell-based therapy for inherited metabolic diseases as well as tissue regenerations in neonatal hypoxic-ischemic encephalopathy, cerebral palsy, and juvenile diabetes.

Stem Cell Banking for Regenerative and Personalized Medicine

Regenerative medicine, tissue engineering and gene therapy offer the opportunity to treat and cure many of today’s intractable afflictions. These approaches to personalized medicine often utilize stem cells to accomplish these goals. However, stem cells can be negatively affected by donor variables such as age and health status at the time of collection, compromising their efficacy. Stem cell banking offers the opportunity to cryogenically preserve stem cells at their most potent state for later use in these applications. Practical stem cell sources include bone marrow, umbilical cord blood and tissue, and adipose tissue. Each of these sources contains stem cells that can be obtained from most individuals, without too much difficulty and in an economical fashion. This review will discuss the advantages and disadvantages of each stem cell source, factors to be considered when contemplating banking each stem cell source, the methodology required to bank each stem cell source, and finally, current and future clinical uses of each stem cell source.

Autologous cord blood therapy for infantile cerebral palsy: from bench to bedside

About 17 million people worldwide live with cerebral palsy, the most common disability in childhood, with hypoxic-ischemic encephalopathy, preterm birth, and low birth weight being the most important risk factors. This review will focus on recent developments in cell therapy for infantile cerebral palsy by transplantation of autologous umbilical cord blood. There are only 4 publications available at present; however, the observations made along with experimental data in vivo and in vitro may be of utmost importance clinically, so that a review at an early developmental stage of this new therapeutic concept seems justified. Particularly, since the first published double-blind randomized placebo-controlled trial in a paradigm using allogeneic cord blood and erythropoietin to treat cerebral palsy under immunosuppression showed beneficial therapeutic effects in infantile cerebral palsy, long-held doubts about the efficacy of this new cell therapy are dispelled and a revision of therapeutic views upon an ailment, for which there is no cure at present, is warranted. Hence, this review will summarize the available information on autologous cord blood therapy for cerebral palsy and that on the relevant experimental work as far as potential mechanisms and modes of action are concerned.

Umbilical cord blood therapy potentiated with erythropoietin for children with cerebral palsy: a double-blind, randomized, placebo-controlled trial

Allogeneic umbilical cord blood (UCB) has therapeutic potential for cerebral palsy (CP). Concomitant administration of recombinant human erythropoietin (rhEPO) may boost the efficacy of UCB, as it has neurotrophic effects. The objectives of this study were to assess the safety and efficacy of allogeneic UCB potentiated with rhEPO in children with CP. Children with CP were randomly assigned to one of three parallel groups: the pUCB group, which received allogeneic UCB potentiated with rhEPO; the EPO group, which received rhEPO and placebo UCB; and the Control group, which received placebo UCB and placebo rhEPO. All participants received rehabilitation therapy. The main outcomes were changes in scores on the following measures during the 6 months treatment period: the gross motor performance measure (GMPM), gross motor function measure, and Bayley scales of infant development-II (BSID-II) Mental and Motor scales (18). F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG-PET/CT) and diffusion tensor images (DTI) were acquired at baseline and followed up to detect changes in the brain. In total, 96 subjects completed the study. Compared with the EPO (n = 33) and Control (n = 32) groups, the pUCB (n = 31) group had significantly higher scores on the GMPM and BSID-II Mental and Motor scales at 6 months. DTI revealed significant correlations between the GMPM increment and changes in fractional anisotropy in the pUCB group. ¹⁸F-FDG-PET/CT showed differential activation and deactivation patterns between the three groups. The incidence of serious adverse events did not differ between groups. In conclusion, UCB treatment ameliorated motor and cognitive dysfunction in children with CP undergoing active rehabilitation, accompanied by structural and metabolic changes in the brain. Stem Cells2013;31:581–591

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.

Ethical issues in neurogenetic disorders

The field of neurogenetics is moving so rapidly that new discoveries are announced almost weekly. The tools available for the diagnosis of neurogenetic disorders have become powerful and complex, and raise new ethical dilemmas that did not exist just a few years ago. In addition to previous concerns about presymptomatic genetic testing and carrier testing, the widening availability of next-generation sequencing raises concerns about the reporting of incidental findings of unclear significance. Genetically targeted therapies have now been proven to be efficacious for a few neurogenetic diseases, and it is likely that gene therapies and cell-based therapies will soon be applied to other neurologic disorders. These therapies are generally quite expensive compared to other treatments. Given the cost constraints that will be needed in the healthcare system in the United States and other countries, and the likelihood that new genetically targeted therapies will be introduced, society will face difficult questions regarding its obligations to fund expensive therapies both for large populations and for small numbers of patients with rare diseases. Potential conflicts of interest involving both individuals and institutions will need ongoing vigilance. Scientific advances will continue to raise consequential ethical questions in the field of neurogenetics.

Allogeneic hematopoietic stem cell transplantation in children with sickle cell disease

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) represents the only curative treatment for sickle cell disease (SCD), being successful in around 85-90% of patients. Mortality and long-term morbidity (including infertility, gonadal failure, and chronic graft-vs.-host disease) associated with conventional approaches curtail the number of patients who undergo allo-HSCT. Recently, it has been demonstrated that cord blood is as effective as and possibly safer than bone marrow in pediatric patients with SCD. Likewise, transplant strategies based on the use of reduced-intensity regimens and the induction of mixed chimerism have been explored to decrease allo-HSCT short- and long-term complications.

Transplantation of umbilical cord-derived mesenchymal stem cells as a novel strategy to protect the central nervous system: technical aspects, preclinical studies, and clinical perspectives

The prevention of perinatal neurological disabilities remains a major challenge for public health, and no neuroprotective treatment to date has proven clinically useful in reducing the lesions leading to these disabilities. Efforts are, therefore, urgently needed to test other neuroprotective strategies including cell therapies. Although stem cells have raised great hopes as an inexhaustible source of therapeutic products that could be used for neuroprotection and neuroregeneration in disorders affecting the brain and spinal cord, certain sources of stem cells are associated with potential ethical issues. The human umbilical cord (hUC) is a rich source of stem and progenitor cells including mesenchymal stem cells (MSCs) derived either from the cord or from cord blood. hUC MSCs (hUC-MSCs) have several advantages as compared to other types and sources of stem cells. In this review, we will summarize the most recent findings regarding the technical aspects and the preclinical investigation of these promising cells in neuroprotection and neuroregeneration, and their potential use in the developing human brain. However, extensive studies are needed to optimize the administration protocol, safety parameters, and potential preinjection cell manipulations before designing a controlled trial in human neonates.

Safety and feasibility of countering neurological impairment by intravenous administration of autologous cord blood in cerebral palsy

Backgrounds

We conducted a pilot study of the infusion of intravenous autologous cord blood (CB) in children with cerebral palsy (CP) to assess the safety and feasibility of the procedure as well as its potential efficacy in countering neurological impairment.

Methods

Patients diagnosed with CP were enrolled in this study if their parents had elected to bank their CB at birth. Cryopreserved CB units were thawed and infused intravenously over 10~20 minutes. We assessed potential efficacy over 6 months by brain magnetic resonance imaging (MRI)-diffusion tensor imaging (DTI), brain perfusion single-photon emission computed tomography (SPECT), and various evaluation tools for motor and cognitive functions.

Results

Twenty patients received autologous CB infusion and were evaluated. The types of CP were as follows: 11 quadriplegics, 6 hemiplegics, and 3 diplegics. Infusion was generally well-tolerated, although 5 patients experienced temporary nausea, hemoglobinuria, or urticaria during intravenous infusion. Diverse neurological domains improved in 5 patients (25%) as assessed with developmental evaluation tools as well as by fractional anisotropy values in brain MRI-DTI. The neurologic improvement occurred significantly in patients with diplegia or hemiplegia rather than quadriplegia.

Conclusions

Autologous CB infusion is safe and feasible, and has yielded potential benefits in children with CP.

Stem cell therapy for neonatal brain injury: perspectives and challenges

Cerebral palsy is a major health problem caused by brain damage during pregnancy, delivery, or the immediate postnatal period. Perinatal stroke, intraventricular hemorrhage, and asphyxia are the most common causes of neonatal brain damage. Periventricular white matter damage (periventricular leukomalacia) is the predominant form in premature infants and the most common antecedent of cerebral palsy. Stem cell treatment has proven effective in restoring injured organs and tissues in animal models. The potential of stem cells for self-renewal and differentiation translates into substantial neuroprotection and neuroregeneration in the animal brain, with minimal risks of rejection and side effects. Stem cell treatments described to date have used neural stem cells, embryonic stem cells, mesenchymal stem cells, umbilical cord stem cells, and induced pluripotent stem cells. Most of these treatments are still experimental. In this review, we focus on the efficacy of stem cell therapy in animal models of cerebral palsy, and discuss potential implications for current and future clinical trials.

Human placenta and chorion: potential additional sources of hematopoietic stem cells for transplantation

BACKGROUND

Hematopoietic stem cell (HSC) transplantation is an essential element of medical therapy, leading to cures of previously incurable hematological and nonhematological diseases. Many patients do not find matched donors in a timely manner, which has driven efforts to find alternative pools of transplantable HSCs. The use of umbilical cord blood (UCB) as a source of transplantable HSCs began more than two decades ago. However, the use of UCB as a reliable source of HSCs for transplantation still faces crucial challenges: the number of HSCs present in a unit of UCB is usually sufficient for younger children but not for adults, and the persistent delayed engraftment often seen can result in high rates of infection and mortality.

STUDY DESIGN AND METHODS

We propose a new approach to a solution of these problems: a potential increase of the limited number of UCB-HSCs available by harvesting HSCs contained in the placenta and the fetal chorionic membrane available at birth.

RESULTS

We investigated the presence of hematopoietic progenitors and HSCs in human placenta and chorion at different gestational ages. The characterization of these cells was performed by flow cytometry and immunolocalization, and their functional status was investigated by transplanting them into immunodeficient mice.

CONCLUSION

HSCs are present in extraembryonic tissues and could be banked in conjunction to the UCB-HSCs. This novel approach could have a large impact on the field of HSC banking and, more crucially, on the outcome of patients undergoing this treatment by greatly improving the use of life-saving hematopoietic transplants.

The rise of cellular therapy

In 1938, the field of Transfusion Medicine began as the simpler entity - Blood Banking. It was a discipline that focused on collecting, processing, storing and distributing end stage blood cells, plasma and plasma fractions to patients. Over the years, the field progressed to include clinical patient services such as apheresis technology and with the development of stem cell transplantation as a standard of care, Cell Therapy. Now the discipline is also finding a niche in the area of Regenerative Medicine. The role played by Transfusion Medicine practitioners in Cell Therapy and Regenerative Medicine was predicated on many factors: (1) pre-existing, established protocols for therapeutic leukapheresis, (2) prior experience with mononuclear cell collection and processing, (3) long term familiarity with, and a clear understanding of, cGMP and cGLP guidelines, Federal regulations, and the voluntary standards established by various organizations, (4) close relationships with practitioners in clinical departments of medicine, pediatrics, oncology, surgery, and their subspecialty areas. While the initial Cell Therapy programs related primarily to hematopoietic stem cell transplantation, as Regenerative Medicine programs developed, transfusion specialists found it to be a related field that would also benefit from their input. Cell Therapy and Regenerative Medicine, now provide fertile soil for the seeds of Transfusion Medicine to grow. The once narrowly defined field of Blood Banking now encompasses involvement in major new Cellular Therapy/Regenerative Medicine research protocols related to treatment of patients with cancer as well as renal, hepatic and cardiac illnesses. This in turn provides opportunities for residents and fellows to consider robust careers in the field of Transfusion Medicine. In this manner we will move forward with one eye on the past and another on the promising future.

Unrelated cord blood transplantation for thalassaemia: a single-institution experience of 35 patients

Our study was designed to prospectively determine whether or not unrelated cord blood transplantation (CBT) can produce outcomes comparable to related donor transplantation for children with β-thalassaemia. In 35 patients, 40 transplants were performed between October 2003 and September 2009. HLA matching at enrolment was 6/6 (n=8), 5/6 (n=16), 4/6 (n=27), or 3/6 (n=1) by low-resolution HLA-A, -B, and high-resolution DRB1. These patients received non-manipulated grafts without ex vivo expansion or T-cell depletion. The median number of nucleated and CD34+ cells infused was 7.8 × 10(7)/kg (range, 2.8-14.7 × 10(7)/kg) and 4.0 × 10(5)/kg (range, 1.7-19.9 × 10(5)/kg), respectively. The 5-year OS and thalassaemia-free survival after the first transplant were 88.3 and 73.9%, respectively. The cumulative incidence of TRM at 2 years was 11.7%. Fourteen patients developed chronic skin GVHD. Thirty patients were alive and transfusion-independent with a Lansky performance score ≥80% achieved between 6 and 76 months post transplant (median, 36 months). These data compare acceptably with the survival rates of related-donor BMT for thalassaemia and suggest that patients without an available HLA-compatible sibling but who have well-matched unrelated donors should also be considered for CBT.

Review of chronic graft-versus-host disease in children after allogeneic stem cell transplantation: nursing perspective

This review presents a summary of the research literature related to the incidence and risk factors for chronic graft-versus-host disease in children following allogeneic hematopoietic stem cell transplantation. The range of incidence of chronic graft-versus-host disease in children found in this review was large, from 0% to 46%. Incidence of chronic graft-versus-host disease was influenced by sample size, time posttransplantation, and stem cell source. Characteristics of the person (eg, child's age and gender) and disease/treatment (eg, sources of transplant) are associated with chronic graft-versus-host disease in children after stem cell transplantation. Person and disease/treatment characteristics provide a framework for understanding the factors associated with chronic graft-versus-host disease symptom experiences in children after stem cell transplantation. Timely assessment of presenting chronic graft-versus-host disease symptoms is critical for treatment and prognosis. Nursing interventions should focus on educating children and parents about the signs and symptoms of chronic graft-versus-host disease. The summary of supportive nursing care for children with chronic graft-versus-host disease provides important information to tailor effective management strategies for children with chronic graft-versus-host disease.

Inefficient dystrophin expression after cord blood transplantation in Duchenne muscular dystrophy

We report a boy who received two allogeneic stem cell transplantations from umbilical cord donors to treat chronic granulomatous disease (CGD). The CGD was cured after the second transplantation, but 2.5 years later he was diagnosed with Duchenne muscular dystrophy (DMD). Examinations of his DNA, muscle tissue, and myoblast cultures derived from muscle tissue were performed to determine whether any donor dystrophin was being expressed. The boy was found to have a large-scale deletion on the X chromosome that spanned the loci for CYBB and DMD. The absence of dystrophin led to muscle histology characteristic of DMD. Analysis of myofibers demonstrated no definite donor cell engraftment. This case suggests that umbilical cord-derived hematopoietic stem cell transplantation will not be efficacious in the therapy of DMD without additional interventions that induce engraftment of donor cells in skeletal muscle.

Flow cytometric identification of CD93 expression on naive T lymphocytes (CD4(+)CD45RA (+) cells) in human neonatal umbilical cord blood

Human CD93 has a molecular weight of about 100 kDa and is selectively expressed by myeloid cell lineages in peripheral blood (PB) mononuclear cells. Although CD93 was initially identified as a receptor for complement component 1, subcomponent q phagocytosis (C1qRp) involved in the C1q-mediated enhancement of the phagocytosis of various antigens, several recent studies have reported that CD93 is not a receptor for the C1q-mediated enhancement of phagocytosis. The expression patterns of CD93 have been previously investigated in PB mononuclear cells (lymphocytes, monocytes, and granulocytes) from adult PB and neonatal umbilical cord blood (UCB), and the expression of CD93 was not found on lymphocytes from either normal adult PB or neonatal UCB. However, the detection of CD93 expression in neonatal UCB using CD93 monoclonal antibodies (mAbs) that recognize different antigenic epitopes remains poorly understood. In this study, we examined the expression of CD93 on lymphocytes, monocytes, and granulocytes from neonatal UCB using four different types of CD93 mAb detection probes, mNI-11, R139, R3, and X-2, using flow cytometric and western blot analyses. We found that CD93, as defined using all four mAbs, was expressed on monocytes and granulocytes in PB mononuclear cells from adult PB and neonatal UCB. On the other hand, we observed for the first time that the expression of CD93 on lymphocytes in neonatal UCB can only be detected using the mNI-11 mAb, established in our laboratory, and not with commercially available CD93 mAbs (R139, R3, and X-2). However, CD93 expression on lymphocytes from normal adults was not detected using any of the four CD93 mAbs. Two-color flow cytometric analyses showed that the CD93 recognized by mNI-11 mAb was expressed on CD3(+) T lymphocytes (mainly CD4(+) helper T lymphocytes), but not on CD19(+) B lymphocytes or on CD8(+) suppressor/cytotoxic T lymphocytes from neonatal UCB. In addition, CD93 was expressed on CD45RA(+) (naive antigen) lymphocytes from neonatal UCB, but not on CD45RO(+) (memory antigen) lymphocytes from neonatal UCB or on CD45RA(+) and CD45RO(+) lymphocytes from normal adult PB. Three-color flow cytometric analysis showed that CD93 was co-expressed on naive T lymphocytes (CD4(+)CD45RA(+)) from neonatal UCB. In a western blot analysis, the CD93 mAb (mNI-11) immunoprecipitated at a molecular weight of 98 kDa, identified as a CD93 molecule, in the CD4(+)CD45RA(+) cells from neonatal UCB but not from adult PB, similar to the results in the human monocyte-like cell line U937 (human CD93-positive cells). Taken together, these results provide the first direct evidence of a novel/naive cell population (CD4(+)CD45RA(+)CD93(+)) in neonatal UCB that may have an important role in cell biology, transplantation, and immature/mature immune responses.

Biosafety assessment of site-directed transgene integration in human umbilical cord-lining cells

Biosafety and efficacy considerations that impede clinical application of gene therapy could be addressed by nonviral ex vivo cell therapy, utilizing transgenic cells that have been comprehensively pre-evaluated for genotoxic potential and transgene expression. We evaluated the genotoxic potential of phiC31 bacteriophage integrase-mediated transgene integration in cord-lining epithelial cells (CLECs) readily cultured from the outer membrane of human umbilical cords, by sequencing and mapping integration sites, spectral karyotyping, high-resolution genome copy number, transcriptome, and transgene copy number analyses and in vivo tumorigenicity. Of 44 independent integration events, <5% were exonic and 85% of modified cells had integrated <or=2 transgene(s). Expression of 95.6% of genes was unaltered in modified cells. Only three small regions showed genome copy number changes that did not correlate with altered gene expression or integration sites. Spectral karyotyping revealed rare nonrecurrent occurrence of three different translocations. Integrase-modified cells were not tumorigenic in immunocompromised mice for at least 4 months. Stable integration of a human factor VIII (FVIII) construct conferred durable FVIII secretion in vitro. Xenoimplantation of FVIII-secreting CLECs in immunocompetent hemophilic mice achieved significant phenotypic correction. Pre-evaluated clonal populations of phiC31 integrase-modified CLECs could be useful as bioimplants for monogenic diseases such as hemophilia.

Non-haematological uses of cord blood stem cells

Embryonic stem (ES) cell therapies are often promoted as the optimal stem cell source for regenerative medicine applications because of their ability to develop into any tissue in the body. Unfortunately, ES cell applications are currently limited by ethical, political, biological and regulatory hurdles. However, multipotent non-ES cells are available in large numbers in umbilical cord blood (CB). CB stem cells are capable of giving rise to hematopoietic, epithelial, endothelial and neural tissues both in vitro and in vivo. Thus, CB stem cells are amenable to treat a wide variety of diseases including cardiovascular, ophthalmic, orthopaedic, neurological and endocrine diseases. In addition, the recent use of CB in several regenerative medicine clinical studies has demonstrated its pluripotent nature. Here we review the latest developments in the use of CB in regenerative medicine. Examples of these usages include cerebral palsy and type I diabetes. The numbers of individuals affected with each of these diseases are estimated at 10 000 infants diagnosed with cerebral palsy annually and 15 000 youths diagnosed with type 1 diabetes annually. A summary of the initial results from such clinical studies using autologous cord blood stem cells will be presented.

Bone marrow transplantation for primary immunodeficiency diseases

Advances in immunology have led to a breathtaking expansion of recognized primary immunodeficiency diseases (PID) with over 120 disease-related genes identified. In North America alone more than 1000 children have received allogeneic blood or marrow transplant over the past 30 years, with the majority surviving long term. This review presents results and highlights challenges and notable advances, including novel less toxic conditioning regimens, to transplant the more common and severe forms of PID. HLA-matched sibling donors remain the ideal option, however, advances in living donor unrelated HSCT and banked umbilical cord blood grafts provide hope for all children with severe PID.

Transplantation immunology: solid organ and bone marrow

Development of the field of organ and tissue transplantation has accelerated remarkably since the human MHC was discovered in 1967. Matching of donor and recipient for MHC antigens has been shown to have a significant positive effect on graft acceptance. The roles of the different components of the immune system involved in the tolerance or rejection of grafts and in graft-versus-host disease have been clarified. These components include antibodies, antigen-presenting cells, helper and cytotoxic T-cell subsets, immune cell-surface molecules, signaling mechanisms, and cytokines. The development of pharmacologic and biological agents that interfere with the alloimmune response has had a crucial role in the success of organ transplantation. Combinations of these agents work synergistically, leading to lower doses of immunosuppressive drugs and reduced toxicity. Reports of significant numbers of successful solid-organ transplantations include those of the kidneys, liver, heart, and lung. The use of bone marrow transplantation for hematologic diseases, particularly hematologic malignancies and primary immunodeficiencies, has become the treatment of choice in many of these conditions. Other sources of hematopoietic stem cells are also being used, and diverse immunosuppressive drug regimens of reduced intensity are being proposed to circumvent the mortality associated with the toxicity of these drugs. Gene therapy to correct inherited diseases by means of infusion of gene-modified autologous hematopoietic stem cells has shown efficacy in 2 forms of severe combined immunodeficiency, providing an alternative to allogeneic tissue transplantation.

Viability and functional capacity after thawing of hematopoietic progenitor cells cryopreserved at a cord blood stem cell bank in Colombia

OBJECTIVE

To evaluate the viability and functional capacity of hematopoietic progenitor cells from cord blood samples cryopreserved at the Banco de Células Stem de Colombia.

METHODS

After thawing and centrifugation of 20 samples, viable white blood cells were numbered by the trypan blue method and CD34(+)CD45(+dim) hematopoietic progenitor cells were numbered by flow cytometry. Clonogenic assays also tested the functional capacity of viable CD34(+)CD45(+dim) cells.

RESULTS

The median rates of viable CD34(+)CD45(+dim) cells were 99.6% before freezing and 73.0% after thawing (P<0.001). The 20 cultures yielded a median of 12 cells with a lineage of red cells, 17.5 cells with a lineage of white cells, and 10 cells with a mixed lineage.

CONCLUSION

Although the rate of viable CD34(+)CD45(+dim) cells was decreased by 26.6% after thawing by the method we used, the numbers of CD34(+)CD45(+dim) cells that formed colonies were similar to those obtained by other published methods.

Mesenchymal stromal cells promote or suppress the proliferation of T lymphocytes from cord blood and peripheral blood: the importance of low cell ratio and role of interleukin-6

BACKGROUND AIMS

Mesenchymal stromal cells (MSC) have been shown to possess immunomodulatory functions and proposed as a tool for managing or preventing graft-versus-host disease (GvHD) as well as promoting clinical transplantation tolerance. We investigated the capacity of human bone marrow (BM) MSC to modulate the proliferation of T cells obtained from peripheral blood (PB) and umbilical cord blood (CB). We addressed the importance of the MSC:T-cell ratio, requirement for cell contact and impact of soluble factors on the MSC-mediated effects. We also analyzed whether regulatory T cells could be modulated by MSC in co-cultures.

METHODS

The effect of different MSC concentrations on T-cell proliferation induced by allogeneic, mitogenic or CD3/CD28 stimulation was analyzed using bromodeoxyuridine (BrdU) incorporation and carboxyfluorescein diacetate-succinimidyl ester (CFDA-SE) labeling. The level of regulatory T cells was assessed using quantitative real-time polymerase chain reaction (PCR) and flow cytometry analysis.

RESULTS

MSC induced a dose- and contact-dependent inhibition of T-cell proliferation but lymphocytes from CB and PB were differentially affected. At low concentrations, MSC supported both CB and PB T-cell proliferation, rather than inhibiting their proliferation. This supportive effect was contact independent and soluble factors such interleukin-6 (IL-6) appeared to be involved. Interestingly, among the expanded T-cell population in both CB and PB, regulatory T cells were increased and were a part of the new cells promoted by MSC at low doses.

CONCLUSIONS

MSC represent an attractive tool for reducing the lymphocyte response by inhibiting T-cell activation and proliferation as well as promoting tolerance by maintaining and promoting the expansion of regulatory cells. Nevertheless, the dual ability of MSC to either sustain or suppress T-cell proliferation according to conditions should be considered in the context of clinical applications.

Private cord blood banking: current use and clinical future

International private umbilical cord blood banking has expanded rapidly in recent years since the first cord blood transplant which was 20 years ago. Private companies offer parents the opportunity to store umbilical cord blood for the possible future use by their child or other family members. The private cord blood industry has been criticised by a number of professional bodies including the EU Ethics Committee, the Royal College of Obstetrics and Gynaecology, the Royal College of Midwives and the US College of Paediatrics. This review presents the arguments from the opponents of private cord blood banking, and then makes the case for private cord banking based on the latest scientific and clinical evidence.