Protective Effects of Cytomegalovirus DNA Copies ≧1000/mL for AML Patients in Complete Remission After Single Cord Blood Transplantation

Introduction

Current consensus recommends a protective effect of cytomegalovirus (CMV) infection on relapse after peripheral blood or bone marrow hematopoietic stem cell transplantation. However, in cord blood transplantation (CBT), studies of CMV infection, especially CMV viral load, on relapse are limited.

Patients and Methods

Wct e retrospectively analyzed the effect of CMV infection on 3-year outcomes in 249 AML patients according to CMV DNA load (DNA copies <1000/mL and DNA copies ≧1000/mL) within 100 days after CBT. Furthermore, eight-colour flow cytometry was used to detect peripheral blood lymphocyte subsets in 38 patients who received CBT in the last year, and 10 healthy volunteers were included as controls.

Results

The results showed that CMV DNA load did not affect the cumulative incidence of relapse in the whole study population. However, in patients with complete remission status before transplantation, the high CMV DNA load group showed a significantly reduction of relapse than the low CMV DNA load group (3.9% vs 14.6%, p=0.012, respectively), which was confirmed by multivariate analysis (HR 0.23; 95% CI, 0.07–0.73, p = 0.012). Surprisingly, high or low CMV DNA load did not significantly affect non-relapse mortality or overall survival (18.0% vs 17.0%, p=0.777 and 79.0% vs 74.6%, p=0.781, respectively). Besides, the absolute number of CD8⁺ T cells were increased in the high CMV DNA load group compared with the low DNA load group 1 month after CBT (0.20×10⁹/L vs 0.10×10⁹/L, p=0.021, respectively).

Conclusion

DNA copies ≧1000/mL for AML patients in complete remission was associated with a lower incidence of relapse after CBT, which might partly result from the expansion of CMV-related CD8⁺ T cells.

Long-Term Recovery After Endothelial Colony-Forming Cells or Human Umbilical Cord Blood Cells Administration in a Rat Model of Neonatal Hypoxic-Ischemic Encephalopathy

Neonatal hypoxic‐ischemic encephalopathy (NHIE) is a dramatic perinatal complication, associated with poor neurological prognosis despite neuroprotection by therapeutic hypothermia, in the absence of an available curative therapy. We evaluated and compared ready‐to‐use human umbilical cord blood cells (HUCBC) and bankable but allogeneic endothelial progenitors (ECFC) as cell therapy candidate for NHIE. We compared benefits of HUCBC and ECFC transplantation 48 hours after injury in male rat NHIE model, based on the Rice‐Vannucci approach. Based on behavioral tests, immune‐histological assessment and metabolic imaging of brain perfusion using single photon emission computed tomography (SPECT), HUCBC, or ECFC administration provided equally early and sustained functional benefits, up to 8 weeks after injury. These results were associated with total normalization of injured hemisphere cerebral blood flow assessed by SPECT/CT imaging. In conclusion, even if ECFC represent an efficient candidate, HUCBC autologous criteria and easier availability make them the ideal candidate for hypoxic‐ischemic cell therapy. Stem Cells Translational Medicine2017;6:1987–1996

What compatibility in 2017 for the haematopoietic stem cell transplantation?

The diversification of potential donors to perform stem cell allografts now enables to propose a compatible graft cell source adapted to the different clinical situations. Transplants with a geno-identical sibling donor, otherwise with the most HLA-compatible unrelated donor, remain the first-line solutions. Alternative transplants allow to graft patients having no donors in international registries, owing to the rarity of their HLA typing. They are carried out with fairly incompatible grafts and are therefore limited by the existence in the recipient of preformed anti-HLA antibodies which predispose to their rejection. The simple prevention of acute Graft-versus-host disease in haplo-identical transplants, as well as the availability of donors, explain why they have very often replaced placental stem cell transplants. These latter remain useful for pediatric patients or in the absence of family donors.

Clinical-scale expansion of CD34+ cord blood cells amplifies committed progenitors and rapid scid repopulation cells

Umbilical cord blood (UCB) transplantation is associated with long periods of aplastic anaemia. This undesirable situation is due to the low cell dose available per unit of UCB and the immaturity of its progenitors. To overcome this, we present a cell culture strategy aimed at the expansion of the CD34⁺ population and the generation of granulocyte lineage-committed progenitors. Two culture products were produced after either 6 or 14days of in vitro expansion, and their characteristics compared to non-expanded UCB CD34⁺ controls in terms of phenotype, colony-forming activity and multilineage repopulation potential in NOD-scid IL2Rγ^null mice. Both expanded cell products maintained rapid SCID repopulation activity similar to the non-expanded control, but 14-day cultured cells showed impaired long term SCID repopulation activity. The process was successfully scaled up to clinically relevant doses of 89×10⁶ CD34⁺ cells committed to the granulocytic lineage and 3.9×10⁹ neutrophil precursors in different maturation stages. Cell yields and biological properties presented by the cell product obtained after 14days in culture were superior and therefore this is proposed as the preferred production setup in a new type of dual transplant strategy to reduce aplastic periods, producing a transient repopulation before the definitive engraftment of the non-cultured UCB unit. Importantly, human telomerase reverse transcriptase activity was undetectable, c-myc expression levels were low and no genetic abnormalities were found, as determined by G-banding karyotype, further confirming the safety of the expanded product.

Alternative donor transplantation--"mixing and matching": the role of combined cord blood and haplo-identical donor transplantation (haplo-cord SCT) as a treatment strategy for patients lacking standard donors?

In the past decade, haplo-cord stem cell transplantation (SCT) using myeloablative or reduced intensive conditioning regimens has been shown to result in reliable and fast engraftment of neutrophils and platelets comparable to HLA-matched donors and much faster than after cord stem cell transplant. Haplo-cord SCT also has a low incidence of early non-relapse mortality, low incidences of acute and chronic graft-vs-host disease (GVHD), and excellent graft-vs-leukemia (GVL) effects. Favorable long-term outcomes for high-risk patients with hematologic malignancies have been reported, including older patients. Haplo-cord SCT will likely overcome the limitations of cell dose during cord stem cell selection and might significantly expand the use of cord stem cell transplant in the adult population. The comparable survival outcomes of matched related donor (MRD), matched unrelated donor (MUD), and haplo-cord stem cell transplant strongly argue that haplo-cord SCT should be considered as effective alternative stem cell transplant for high-risk patients lacking standard donors. Further improvement in supportive care and incorporation of a better understanding of the human fetal immune development into the haplo-cord SCT are required to further improve this strategy.

Human umbilical cord blood-derived monocytes improve cognitive deficits and reduce amyloid-β pathology in PSAPP mice

Alzheimer's disease (AD) is the fourth major cause of mortality in the elderly in the US and the leading cause of dementia worldwide. While pharmacological targets have been discovered, there are no true disease-modifying therapies. We have recently discovered that multiple low-dose infusions of human umbilical cord blood cells (HUCBCs) ameliorate cognitive impairments and reduce Aβ-associated neuropathology in PSAPP transgenic mice. However, the mechanism for these effects of HUCBCs remains unclear. In the present study, we examined whether monocytes, as important components of HUCBCs, would have beneficial outcomes on the reduction of AD-like pathology and associated cognitive impairments in PSAPP transgenic AD model mice. PSAPP mice and their wild-type littermates were treated monthly with an infusion of peripheral human umbilical cord blood cell (HUCBC)-derived monocytes over a period of 2 and 4 months, followed by behavioral evaluations, biochemical, and histological analyses. The principal findings of the present study confirmed that monocytes derived from HUCBCs (CB-M) play a central role in HUCBC-mediated cognition-enhancing and Aβ pathology-ameliorating activities. Most importantly, we found that compared with CB-M, aged monocytes showed an ineffective phagocytosis of Aβ, while exogenous soluble amyloid precursor protein α (sAPPα) could reverse this deficiency. Pretreating monocytes with sAPPα upregulates Aβ internalization. Our further studies suggested that sAPPα could form a heterodimer with Aβs, with the APP672-688 (Aβ1-16) region being responsible for this effect. This in turn promoted binding of these heterodimers to monocyte scavenger receptors and thus promoted enhanced Aβ clearance. In summary, our findings suggest an interesting hypothesis that peripheral monocytes contribute to Aβ clearance through heterodimerization of sAPPα with Aβ. Further, declined or impaired sAPPα production, or reduced heterodimerization with Aβ, would cause a deficiency in Aβ clearance and thus accelerate the pathogenesis of AD.

General and Virus-Specific Immune Cell Reconstitution after Double Cord Blood Transplantation

Cord blood transplantation (CBT) is curative for many patients with hematologic malignancies but is associated with delayed immune recovery and an increased risk of viral infections compared with HLA-matched bone marrow or peripheral blood progenitor cell transplantation. In this study we evaluated the significance of lymphocyte recovery in 125 consecutive patients with hematologic malignancies who underwent double-unit CBT (DUCBT) with an antithymocyte globulin-containing regimen at our institution. A subset of 65 patients was prospectively evaluated for recovery of T, natural killer (NK), and B cells, and in 46 patients we also examined viral-specific T cell recovery against adenovirus, Epstein-Barr virus, cytomegalovirus, BK virus, respiratory syncytial virus, and influenza antigen. Our results indicate that in recipients of DUCBT, the day 30 absolute lymphocyte count is highly predictive of nonrelapse mortality and overall survival. Immune recovery post-DUCBT was characterized by prolonged CD8+ and CD4+ T lymphopenia associated with preferential expansion of B and NK cells. We also observed profound delays in quantitative and functional recovery of viral-specific CD4+ and CD8+ T cell responses for the first year post-CBT. Taken together, our data support efforts aimed at optimizing viral-specific T cell recovery to improve outcomes post-CBT.

Hematopoietic Cell Transplantation for Older Patients with MDS

The incidence of myeloid malignancies, including myelodysplastic syndromes (MDS) increases with age. While several therapeutic modalities have been developed, for most of these patients the only treatment with curative potential is allogeneic hematopoietic cell transplantation (HCT). The development of reduced/low intensity transplant conditioning regimens allows to successfully transplant patients in their ‘60s and even ‘70s, although comorbidities may determine who does come to transplantation and who does not. Also, as many as half of the patients will develop graft versus host disease (GVHD), even with HLA matched donors, requiring therapy for extended periods of time, and GVHD and treatment with glucocorticoids is likely to impact the quality of life. Nevertheless, dependent upon disease stage at HCT, the presence of comorbidities and the regimen used, 30% to 50% of patients 60 years of age or older, may survive long-term cured of their disease. Future studies should focus on the incorporation of non-transplant modalities into the overall transplant approach, the prevention of GVHD, and the utilization of immunotherapy to reduce the incidence of relapse and GVHD and further improve overall transplant success.

Nanomedicine-based neuroprotective strategies in patient specific-iPSC and personalized medicine

In recent decades, nanotechnology has attracted major interests in view of drug delivery systems and therapies against diseases, such as cancer, neurodegenerative diseases, and many others. Nanotechnology provides the opportunity for nanoscale particles or molecules (so called “Nanomedicine”) to be delivered to the targeted sites, thereby, reducing toxicity (or side effects) and improving drug bioavailability. Nowadays, a great deal of nano-structured particles/vehicles has been discovered, including polymeric nanoparticles, lipid-based nanoparticles, and mesoporous silica nanoparticles. Nanomedical utilizations have already been well developed in many different aspects, including disease treatment, diagnostic, medical devices designing, and visualization (i.e., cell trafficking). However, while quite a few successful progressions on chemotherapy using nanotechnology have been developed, the implementations of nanoparticles on stem cell research are still sparsely populated. Stem cell applications and therapies are being considered to offer an outstanding potential in the treatment for numbers of maladies. Human induced pluripotent stem cells (iPSCs) are adult cells that have been genetically reprogrammed to an embryonic stem cell-like state. Although the exact mechanisms underlying are still unclear, iPSCs are already being considered as useful tools for drug development/screening and modeling of diseases. Recently, personalized medicines have drawn great attentions in biological and pharmaceutical studies. Generally speaking, personalized medicine is a therapeutic model that offers a customized healthcare/cure being tailored to a specific patient based on his own genetic information. Consequently, the combination of nanomedicine and iPSCs could actually be the potent arms for remedies in transplantation medicine and personalized medicine. This review will focus on current use of nanoparticles on therapeutical applications, nanomedicine-based neuroprotective manipulations in patient specific-iPSCs and personalized medicine.

Gene and miRNA expression profiles of hematopoietic progenitor cells vary depending on their origin

Hematopoietic progenitor cells (HPCs) from granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood (G-PB), bone marrow (BM), or umbilical cord blood (CB) have differing biological properties and differing kinetics of engraftment post-transplantation, which might be explained, at least in part, by differing gene and miRNA expression patterns. To assess the differences in gene and miRNA expression, we analyzed whole genome expression profiles as well as the expression of 384 miRNAs in CD34(+) cells isolated from 18 healthy individuals (6 individuals per subtype of HPC source). We identified 43 genes and 36 miRNAs differentially expressed in the various CD34(+) cell sources. We observed that CD34(+) cells from CB and BM showed similar gene and miRNA expression profiles, whereas CD34(+) cells from G-PB had a very different expression pattern. Remarkably, 20 of the differentially expressed genes are targets of the differentially expressed miRNAs. Of note, the majority of genes differentially expressed in CD34(+) cells from G-PB are involved in cell cycle regulation, promoting the process of proliferation, survival, hematopoiesis, and cell signaling, and are targets of overexpressed and underexpressed miRNAs in CD34(+) cells from the same source. These data suggest significant differences in gene and miRNA expression among the various HPC sources used in transplantation. We hypothesize that the differentially expressed genes and miRNAs involved in cell cycle and proliferation might explain the differing kinetics of engraftment observed after transplantation of hematopoietic stem cells obtained from these different sources.

Cord blood serum-based eye drops: the impact of donor haematological and obstetric factors on the variability of epidermal growth factor levels

BACKGROUND

Cord blood serum (CBS)-based eye drops are successfully used in corneal epithelial wound healing and are prepared to supply a known amount of epidermal growth factor (EGF). Product standardisation includes expensive EGF dosage in all cord blood (CB) units. The influence of donor obstetric and haematological characteristics on EGF content was evaluated, to exclude unsuitable CBS and pre-select those CB units able to provide the correct EGF supply for healing corneal wounds.

MATERIALS AND METHODS

Data were retrospectively collected from 135 donors included in the Emilia Romagna Cord Blood Bank records. Obstetric characteristics, parity and gestational age of the mother, sex, birth weight and Apgar score of the neonate, placental weight, duration of labour and mode of delivery were considered. Haematological characteristics, CD34+ cell number, and total nucleated cell, white blood cell and platelet counts were recorded. EGF content in CB units was estimated by enzyme-linked immunosorbent assay. Statistical evaluation was performed by Mann-Whitney unpaired and Student's t tests. Correlations between variables were evaluated by using Pearson's (r) or Spearman's (ρ) correlation coefficients.

RESULTS

EGF content was significantly higher in CBS from donors aged <30 years and after vaginal deliveries as compared with scheduled Caesarean sections (1,386±580 vs 1,106±391 pg/mL; P=0.002). EGF content was significantly correlated with duration of labour (r=0.45; P=0.0001), number of CD34+ cells/mL (r=0.3; P=0.002) particularly in vaginal deliveries (r=0.36; P=0.003), mother's age (-0.25; P=0.005), neonate's birth weight (r=0.27; P=0.005), and total nucleated cell (r=0.25; P=0.006), white cell (r=0.29; P=0.001) and platelet (r=0.24; P=0.009) counts. No significant correlations were found between EGF content and parity, gestational age, placental weight, neonate's sex or Apgar scores.

DISCUSSION

EGF levels are higher in CB units from younger mothers (<30 years), with longer labour duration (>6 hours), and higher CD34+ cell content (>0.05×10(6)/mL). In order to optimise the preparation and costs of CBS-based eye drops, pre-selection of CB units is recommended.

Double umbilical cord blood transplantation for hematological malignancies: a long-term analysis from the SFGM-TC registry

Allogeneic hematopoietic stem cell (HSC) transplantation is a curative treatment for many hematologic malignancies for which umbilical cord blood (UCB) represents an alternative source of HSCs. To overcome the low cellularity of one UCB unit, double UCB transplantation (dUCBT) has been developed in adults. We have analyzed the outcome of 136 patients who underwent dUCBT reported to the SFGM-TC registry between 2005 and 2007. Forty-six patients received myeloablative regimens, and 90 patients received reduced-intensity conditioning regimens. There were 84 cases of leukemia, 17 cases of non-Hodgkin lymphoma, 11 cases of myeloma, and 24 other hematologic malignancies. At transplantation, 40 (29%) patients were in complete remission. At day 60 after transplantation, the cumulative incidence of neutrophil recovery was 91%. We observed one UCB unit domination in 88% of cases. The cumulative incidence of day 100 acute graft-versus-host disease, chronic graft-versus-host disease, transplant-related mortality, and relapse at 2 years were 36%, 23%, 27%, and 28% respectively. After a median follow-up of 49.5 months, the 3-year probabilities of overall and progression-free survival were 41% and 35%, respectively, with a significant overall survival advantage when male cord engrafted male recipients. We obtained a long-term plateau among patients in complete remission, which makes dUCBT a promising treatment strategy for these patients.

Pluripotent possibilities: human umbilical cord blood cell treatment after neonatal brain injury

Perinatal hypoxic-ischemic brain injury and stroke in the developing brain remain important causes of chronic neurologic morbidity. Emerging data suggest that transplantation of umbilical cord blood-derived stem cells may have therapeutic potential for neuroregeneration and improved functional outcome. The pluripotent capacity of stem cells from the human umbilical cord blood provides simultaneous targeting of multiple neuropathologic events initiated by a hypoxic-ischemic insult. Their high regenerative potential and naïve immunologic phenotype makes them a preferable choice for transplantation. A multiplicity of transplantation protocols have been studied with a variety of brain injury models; however, only a few have been conducted on immature animals. Biological recipient characteristics, such as age and sex, appear to differentially modulate responses of the animals to the transplanted cord blood stem cells. Survival, migration, and function of the transplanted cells have also been studied and reveal insights into the mechanisms of cord blood stem cell effects. Data from preclinical studies have informed current clinical safety trials of human cord blood in neonates, and further work is needed to continue progress in this field.

Umbilical cord blood transplantation supported by third-party donor cells: rationale, results, and applications

Low incidence of graft-versus-host disease provides the major rational for pursuing umbilical cord blood (UCB) stem cell transplantation (SCT). Considerable evidence also suggests a lower rate of recurrence after UCB SCT than after transplantation from adult donors. Recent advances in understanding of the human fetal immune development provide a rational underpinning for these clinical outcomes. The fetal immune system is geared toward maintaining tolerance to foreign antigens, particularly to the maternal antigens to which it is exposed throughout gestation. To this purpose it is dominated by a unique population of peripheral T regulatory cells that actively maintain tolerance. This and other features of the UCB lymphoid system explains the low incidence of graft-versus-host disease and superior outcomes of UCB SCT with noninherited maternal antigen-matched grafts. At the same time, highly sensitized maternal microchimeric cells are frequently detected in UCB and likely contribute to superior graft-versus-leukemia effects and low rates of disease recurrence in inherited paternal antigen-matched UCB recipients. However, historically erratic and slow hematopoietic recovery after UCB SCT leads to increased early morbidity and mortality, excessive hospitalization, and increased costs. This has held up the widespread utilization of UCB SCT in adults. Here we summarize recent data on UCB SCT with an emphasis on studies of co-infusion of adult CD34 selected hematopoietic stem cells with UCB SCT. This procedure, through transient engraftment of adult hematopoietic stem cells, largely overcomes the problem of delayed engraftment. It also results in predictable engraftment of a UCB with the desired characteristics. We also briefly discuss unresolved issues and possible future applications of this technology.

Exogenous endothelial cells as accelerators of hematopoietic reconstitution

Despite the successes of recombinant hematopoietic-stimulatory factors at accelerating bone marrow reconstitution and shortening the neutropenic period post-transplantation, significant challenges remain such as cost, inability to reconstitute thrombocytic lineages, and lack of efficacy in conditions such as aplastic anemia. A possible means of accelerating hematopoietic reconstitution would be administration of cells capable of secreting hematopoietic growth factors. Advantages of this approach would include: a) ability to regulate secretion of cytokines based on biological need; b) long term, localized production of growth factors, alleviating need for systemic administration of factors that possess unintended adverse effects; and c) potential to actively repair the hematopoietic stem cell niche. Here we overview the field of hematopoietic growth factors, discuss previous experiences with mesenchymal stem cells (MSC) in accelerating hematopoiesis, and conclude by putting forth the rationale of utilizing exogenous endothelial cells as a novel cellular therapy for acceleration of hematopoietic recovery.

US public cord blood banking practices: recruitment, donation, and the timing of consent

BACKGROUND

Cord blood has moved rapidly from an experimental stem cell source to an accepted and important source of hematopoietic stem cells. There has been no comprehensive assessment of US public cord blood banking practices since the Institute of Medicine study in 2005.

STUDY DESIGN AND METHODS

Of 34 US public cord blood banks identified, 16 participated in our qualitative survey of public cord blood banking practices. Participants took part in in-depth telephone interviews in which they were asked structured and open-ended questions regarding recruitment, donation, and the informed consent process at these banks.

RESULTS

Thirteen of 16 participants reported a variably high percentage of women who consented to public cord blood donation. Fifteen banks offered donor registration at the time of hospital admission for labor and delivery. Seven obtained full informed consent and medical history during early labor and eight conducted some form of phased consent and/or phased medical screening and history. Nine participants identified initial selection of the collection site location as the chief mode by which they recruited minority donors.

CONCLUSION

Since 2005, more public banks offer cord blood donor registration at the time of admission for labor and delivery. That and the targeted location of cord blood collection sites are the main methods used to increase access to donation and HLA diversity of banked units. Currently, the ability to collect and process donations, rather than donor willingness, is the major barrier to public cord blood banking.

Human umbilical cord is a unique and safe source of various types of stem cells suitable for treatment of hematological diseases and for regenerative medicine

Cord blood (CB) is a rich source of hematopoietic stem cells (HSCs) and for this reason CB transplantation has been used successfully for the treatment of some malignant and nonmalignant diseases. However, this technique is limited by the relatively low number of HSCs present in each CB unit and by the delayed engraftment of platelets and neutrophils. To bypass these obstacles efforts have been made to develop strategies to expand CB HSCs in vitro for transplantation. CB is also an important source of other stem cells, including endothelial progenitors, mesenchymal stem cells (MSCs), very small embryonic/epiblast-like (VSEL) stem cells, and unrestricted somatic stem cells (USSC), potentially suitable for use in regenerative medicine. For some of these stem cell populations, such as MSCs, clinical studies have been started and for other stem cell populations potential clinical applications have been identified and clinical studies will follow. In addition to CB, other parts of umbilical cord, such as the Wharton's jelly, or tissues strictly linked such as the placenta are also rich sources of stem cells.

A meta-analysis of unrelated donor umbilical cord blood transplantation versus unrelated donor bone marrow transplantation in acute leukemia patients

Umbilical cord blood has emerged as an alternative stem cell source to bone marrow or peripheral blood stem cells. Umbilical cord blood transplantation (UCBT) is also potentially curative for acute leukemia. However, the effect of unrelated donor bone marrow transplantation (UBMT) and UCBT on the outcome of patients with acute leukemia has not been systematically reviewed. In the present meta-analysis, we systematically searched Cochrane Library, MEDLINE, EMBASE, and CNKI up to May 2011. Two reviewers extracted data independently. Seven studies totaling 3389 patients have been assessed. Pooled results found that the incidence of engraftment failure and transplantation-related mortality were higher in UCBT than in UBMT, and relative risks (RRs) were 4.27 (95% confidence interval [CI], 2.94-6.21) and 1.27 (95% CI, 1.01-1.59), respectively. The rates of acute and chronic graft-versus-host disease (GVHD) in the UCBT group were significantly lower than that in the UBMT group, and RRs were 0.71 (95% CI, 0.65-0.79) and 0.69 (95% CI, 0.52-0.91), respectively. The relapse rate was similar between the UCBT and UBMT group. The leukemia-free survival (LFS) and overall survival (OS) were significantly lower in the UCBT group than in the UBMT group; RRs were 1.14 (95% CI, 1.07-1.22) and hazard ratios (HRs) were 1.31 (95% CI, 1.16-1.48), respectively. Subgroup analysis showed that in patients with acute lymphoblastic leukemia (ALL), the survival was similar between UCBT and UBMT.