Autologous cord blood in children with cerebral palsy: a review.

The aim of this narrative review is to report on the current knowledge regarding the clinical use of umbilical cord blood (CB) based on articles from PubMed and clinical trials registered on ClinicalTrials.gov. An increasing amount of evidence suggests that CB may be used for both early diagnostics and treatment of cerebral palsy. The acidity of CB and its biochemical parameters, including dozens of cytokines, growth factors, and other metabolites (such as amino acids, acylcarnitines, phosphatidylcholines, succinate, glycerol, 3-hydroxybutyrate, and O-phosphocholine) are predictors of future neurodevelopment. In addition, several clinical studies confirmed the safety and efficacy of CB administration in both autologous and allogeneic models, including a meta-analysis of five clinical trials involving a total of 328 participants. Currently, nine clinical trials assessing the use of autologous umbilical CB in children diagnosed with hypoxic-ischemic encephalopathy or cerebral palsy are in progress. The total population assessed in these trials exceeds 2500 patients.

Quality and exploitation of umbilical cord blood for cell therapy: Are we beyond our capabilities?

There is increasing interest in identifying novel stem cell sources for application in emerging cell therapies. In this context, umbilical cord blood (UCB) shows great promise in multiple clinical settings. The number of UCB banks has therefore increased worldwide, with the objective of preserving potentially life-saving cells that are usually discarded after birth. After a rather long and costly processing procedure, the resultant UCB-derived cell products are cryopreserved until transplantation to patients. However, in many cases, only a small proportion of administered cells engraft successfully. Thus, can we do any better regarding current UCB-based therapeutic approaches? Here we discuss concerns about the use of UCB that are not critically pondered by researchers, clinicians, and banking services, including wasting samples with small volumes and the need for more reliable quality and functional controls to ensure the biological activity of stem cells and subsequent engraftment and treatment efficacy. Finally, we appeal for collaborative agreements between research institutions and UCB banks in order to redirect currently discarded small-volume UCB units for basic and clinical research purposes. Developmental Dynamics 245:710-717, 2016. © 2016 Wiley Periodicals, Inc.

PCR-based methodology for molecular microchimerism detection and quantification.

Peripheral blood microchimerism after pregnancy or solid organ transplantation has been widely studied, but a consensus on its detection has not yet been adopted. The objective of this study was to establish a panel of reproducible molecular polymerase chain reaction (PCR)-based methods for detection and quantification of foreign cells in an individual. We analyzed length polymorphisms generated by short tandem repeat (STR) and variable number tandem repeat (VNTR) markers. Human leukocyte antigen (HLA)-A and -B polymorphisms were detected by reference strand conformation analysis (RSCA). Class II polymorphisms on HLA-DRB1 locus were analyzed both by classical PCR-sequence-specific primers (SSP) and by quantitative PCR (Q-PCR). Also, sex-determining region-y gene (SRY) gene allowed specific male donor discrimination and quantification by Q-PCR in female recipients. Binomial statistical distribution analysis was used for each molecular technique to determine the number of PCR replicates of each sample. This analysis allowed the detection of the lowest detectable microchimerism level, when present. We could detect microchimerism in more than 96% and more than 86% of cases at levels as low as 1:10(5) and 1:10(6) donor per recipient cells (DPRC), respectively, using Q-PCR for SRY or for nonshared HLA-DRB1 alleles. These techniques allowed as low as 1 genome-equivalent cell detection. Lower levels (nanochimerism) could be detected but not quantified because of technique limitations. However, classical PCR methods allowed detection down to 1:10(4) DPRC for HLA-DRB1 PCR-SSP. The clinical application of these techniques in solid organ transplanted recipients showed microchimerism levels ranging from 1:10(4) to 1:10(6) DPRC after kidney or heart transplantation, and 1 log higher (1:10(3) to 1:10(6) DPRC) after liver transplantation. In conclusion, the standardization of molecular microchimerism detection techniques will allow for comparable interpretation of results in microchimerism detection for diagnostic or research studies.

Early hematopoietic microchimerism predicts clinical outcome after kidney transplantation.

BACKGROUND: The presence of a few circulating donor cells in recipient's blood was first thought to be only an epiphenomenon of solid organ transplantation, also called microchimerism, but several authors have suggested that these circulating cells may contribute to tolerance induction. This study aims to assess the rate of microchimerism after kidney transplantation and determine its influence on acute rejection in a 4-year follow-up. METHODS: A total of 84 single-kidney recipients were included for microchimerism detection and quantification 2, 6, 12, and 18 months after transplantation by specific detection of non-shared STR, VNTR, human leukocyte antigen-A, -B, -DRB1, and SRY alleles. Kinetic establishment of microchimerism was monitored in a double kidney transplanted recipient for 150 min after declamping and after 7 days. RESULTS: Microchimerism was detected in 56.2% of kidney recipients 2 months after transplantation (M2): this fell to 30.1% at 12 months. In renal calcineurin inhibitor-based immunosuppression cohort (n=73), the microchimerism-negative group (n=32) showed 37.9% biopsy-proven acute rejection (BPAR), whereas in the microchimerism-positive group (n=41), no recipient did (P<0.001). Regardless of immunosuppression, BPAR incidence was 35.6% and 4.9%, respectively (P<0.001). Multivariate study showed microchimerism as a protective factor against BPAR (odds ratio: 8.3; 95% confidence interval: 1.8 to 37.9; P = 0.006), blinding other well-known rejection-risk variables. Microchimerism M2 presence did not correlate with a multifactorial critical outcome such as late graft loss. CONCLUSION: Microchimerism was frequent after kidney transplantation and correlated with a significantly lower incidence of rejection. We propose that early microchimerism monitoring could help early detection of low rejection-risk recipients.

Nanosized UCMSC-derived extracellular vesicles but not conditioned medium exclusively inhibit the inflammatory response of stimulated T cells: implications for nanomedicine.

Undesired immune responses have drastically hampered outcomes after allogeneic organ transplantation and cell therapy, and also lead to inflammatory diseases and autoimmunity. Umbilical cord mesenchymal stem cells (UCMSCs) have powerful regenerative and immunomodulatory potential, and their secreted extracellular vesicles (EVs) are envisaged as a promising natural source of nanoparticles to increase outcomes in organ transplantation and control inflammatory diseases. However, poor EV preparations containing highly-abundant soluble proteins may mask genuine vesicular-associated functions and provide misleading data. Here, we used Size-Exclusion Chromatography (SEC) to successfully isolate EVs from UCMSCs-conditioned medium. These vesicles were defined as positive for CD9, CD63, CD73 and CD90, and their size and morphology characterized by NTA and cryo-EM. Their immunomodulatory potential was determined in polyclonal T cell proliferation assays, analysis of cytokine profiles and in the skewing of monocyte polarization. In sharp contrast to the non-EV containing fractions, to the complete conditioned medium and to ultracentrifuged pellet, SEC-purified EVs from UCMSCs inhibited T cell proliferation, resembling the effect of parental UCMSCs. Moreover, while SEC-EVs did not induce cytokine response, the non-EV fractions, conditioned medium and ultracentrifuged pellet promoted the secretion of pro-inflammatory cytokines by polyclonally stimulated T cells and supported Th17 polarization. In contrast, EVs did not induce monocyte polarization, but the non-EV fraction induced CD163 and CD206 expression and TNF-α production in monocytes. These findings increase the growing evidence confirming that EVs are an active component of MSC's paracrine immunosuppressive function and affirm their potential for therapeutics in nanomedicine. In addition, our results highlight the importance of well-purified and defined preparations of MSC-derived EVs to achieve the immunosuppressive effect.

The role and potential of umbilical cord blood in an era of new therapies: a review.

In light of pioneering findings in the 1980s and an estimation of more than 130 million global annual births, umbilical cord blood (UCB) is considered to be the most plentiful reservoir of cells and to have regenerative potential for many clinical applications. Although UCB is used mainly against blood disorders, the spectrum of diseases for which it provides effective therapy has been expanded to include non-hematopoietic conditions; UCB has also been used as source for regenerative cell therapy and immune modulation. Thus, collection and banking of UCB-derived cells have become a popular option. However, there are questions regarding the cost versus the benefits of UCB banking, and it also raises complex ethical and legal issues. This review discusses many issues surrounding the conservation of UCB-derived cells and the great potential and current clinical applications of UCB in an era of new therapies. In particular, we describe the practical issues inherent in UCB collection, processing, and long-term storage as well as the different types of 'stem' or progenitor cells circulating in UCB and their uses in multiple clinical settings. Given these considerations, the trend toward UCB will continue to provide growing assistance to health care worldwide.

Impact of umbilical cord blood-derived mesenchymal stem cells on cardiovascular research.

Over the years, cell therapy has become an exciting opportunity to treat human diseases. Early enthusiasm using adult stem cell sources has been tempered in light of preliminary benefits in patients. Considerable efforts have been dedicated, therefore, to explore alternative cells such as those extracted from umbilical cord blood (UCB). In line, UCB banking has become a popular possibility to preserve potentially life-saving cells that are usually discarded after birth, and the number of UCB banks has grown worldwide. Thus, a brief overview on the categories of UCB banks as well as the properties, challenges, and impact of UCB-derived mesenchymal stem cells (MSCs) on the area of cardiovascular research is presented. Taken together, the experience recounted here shows that UCBMSCs are envisioned as attractive therapeutic candidates against human disorders arising and/or progressing with vascular deficit.

Umbilical cord blood for cardiovascular cell therapy: from promise to fact.

Endothelial recovery and cell replacement are therapeutic challenges for cardiovascular medicine. Initially employed in the treatment of blood malignancies due to its high concentration of hematological precursors, umbilical cord blood (UCB) is now a non-controversial and accepted source of both hematopoietic and non-hematopoietic progenitors for a variety of emerging cell therapies in clinical trials. Here, we review the current therapeutic potential of UCB, focusing in recent evidence demonstrating the ability of UCB-derived mesenchymal stem cells to differentiate into the endothelial lineage and to develop new vasculature in vivo.

Fetal-maternal interface: a chronicle of allogeneic coexistence.

The existence of allogeneic cells within an individual has been demonstrated in multiple fields such as hematopoietic stem cell or solid organ transplantation, non-depleted blood transfusions and the most common form which is bidirectional maternal-fetal cell trafficking, whereby cells from the fetus pass through the placental barrier. In order to graphically illustrate this early natural phenomenon that initiates the journey of a child's cells within the mother's blood and other tissues, we used a new procedure in microscopy imaging generating Large Scale Panoramic Pictures (LSPP). This technique can also be extended to explore a broad diversity of experimental models.

Should microchimerism turn into rejection prophylactics?

Non-self cells can circulate in the body of an individual after any sort of contact with an allogeneic source of cells, thus creating a situation of chimerism that can be transient or prolonged over time. This situation may appear after stem cell transplantation, pregnancy, transfusion or transplantation. Concerning transplantation, many hypotheses have been formulated regarding the existence, persistence and role of these circulating cells in the host. We will review the principal hypotheses that have been formulated for years since the first description of non-self circulating cells in mammals to the utilization of artificially induced chimerism protocols for the achievement of tolerance.

Epistasis between HLA-DRB1 parental alleles in a Spanish cohort with multiple sclerosis.

BACKGROUND AND OBJECTIVE: Multiple sclerosis (MS) has been consistently associated with the HLA-DR2 haplotype and particularly with the HLA-DRB1*15 allele. Epistatic interactions between both parental alleles in the DRB1 loci have been shown to modify the MS susceptibility risk. This study investigated the frequencies of various HLA-DRB1 genotypes, their impact on MS susceptibility and their correlation with the clinical severity in a Spanish population. METHODS: A genotype was considered as the combination of the two parental DRB1 alleles. We compared the frequencies of the genotypes in a sporadic MS population (n=380) with those of an unrelated healthy control cohort (n=1088). We correlated the different genotypes with the age at onset, gender distribution, symptoms at onset, course of the disease and progression severity by means of the time to reach the progressive phase and EDSS scores of 3 and 6. RESULTS: We found 81 different genotypes. There were four different MS-predisposing genotypes. Three of them contained the DRB1*15 allele (DRB1*03/15, DRB1*04/15, and DRB1*08/15) and the fourth was homozygote for the DRB1*03 allele. The highest odds ratio was found with the genotype DRB1*08/15 (OR=3.88, 95% CI=1.83-8.26, p<0.01), followed by DRB1*03/03 (OR=3.15, 95% CI=1.93-5.14, p<0.01), DRB1*03/15 (OR=2.72, 95% CI=1.88-3.94, p<0.01) and DRB1*04/15 (OR=2.54, 95% CI=1.64-3.98, p<0.01). The DRB1*01/04 and the DRB1*15/15 genotypes were associated with a shorter time to reach an EDSS score of 6. CONCLUSIONS: Our results show the importance of epistatic interactions among the HLA-DRB1 alleles, modifying the risk for MS as well as its clinical severity.