Dominant unit CD34+ cell dose predicts engraftment after double-unit cord blood transplantation and is influenced by bank practice

We investigated the unit characteristics associated with engraftment after double-unit cord blood (CB) transplantation (dCBT) and whether these could be reliably identified during unit selection. Cumulative incidence of neutrophil engraftment in 129 myeloablative dCBT recipients was 95% (95% confidence interval: 90-98%). When precryopreservation characteristics were analyzed, the dominant unit CD34(+) cell dose was the only characteristic independently associated with engraftment (hazard ratio, 1.43; P = .002). When postthaw characteristics were also included, only dominant unit infused viable CD34(+) cell dose independently predicted engraftment (hazard ratio, 1.95; P < .001). We then examined the determinants of infused viable CD34(+) cell dose (precryopreservation count, postthaw recovery, and postthaw viability) in 402 units thawed at our center. This revealed close correlation between precryopreservation and postthaw CD34(+) cell counts (r(2) = 0.73). Median CD34(+) cell recovery was 101%, although it ranged from 12% to 1480%. Notably, units from non-Netcord Foundation for the Accreditation of Cellular Therapy (Netcord-FACT)-accredited banks were more likely to have low recovery (P < .001). Furthermore, although median postthaw CD34(+) cell viability was 92%, 33 (8%) units had <75% viable CD34(+) cells. Units from non-Netcord-FACT-accredited banks and units with cryovolumes other than 24.5 to 26.0 mL were more likely to have poor postthaw viability. Precryopreservation CD34(+) cell dose and banking practices should be incorporated into CB unit selection.

One-unit versus two-unit cord-blood transplantation for hematologic cancers

BACKGROUND

Umbilical-cord blood has been used as the source of hematopoietic stem cells in an estimated 30,000 transplants. The limited number of hematopoietic cells in a single cord-blood unit prevents its use in recipients with larger body mass and results in delayed hematopoietic recovery and higher mortality. Therefore, we hypothesized that the greater numbers of hematopoietic cells in two units of cord blood would be associated with improved outcomes after transplantation.

METHODS

Between December 1, 2006, and February 24, 2012, a total of 224 patients 1 to 21 years of age with hematologic cancer were randomly assigned to undergo double-unit (111 patients) or single-unit (113 patients) cord-blood transplantation after a uniform myeloablative conditioning regimen and immunoprophylaxis for graft-versus-host disease (GVHD). The primary end point was 1-year overall survival.

RESULTS

Treatment groups were matched for age, sex, self-reported race (white vs. nonwhite), performance status, degree of donor-recipient HLA matching, and disease type and status at transplantation. The 1-year overall survival rate was 65% (95% confidence interval [CI], 56 to 74) and 73% (95% CI, 63 to 80) among recipients of double and single cord-blood units, respectively (P=0.17). Similar outcomes in the two groups were also observed with respect to the rates of disease-free survival, neutrophil recovery, transplantation-related death, relapse, infections, immunologic reconstitution, and grade II-IV acute GVHD. However, improved platelet recovery and lower incidences of grade III and IV acute and extensive chronic GVHD were observed among recipients of a single cord-blood unit.

CONCLUSIONS

We found that among children and adolescents with hematologic cancer, survival rates were similar after single-unit and double-unit cord-blood transplantation; however, a single-unit cord-blood transplant was associated with better platelet recovery and a lower risk of GVHD. (Funded by the National Heart, Lung, and Blood Institute and the National Cancer Institute; ClinicalTrials.gov number, NCT00412360.).

Influence of flap prefabrication on seeding of subcutaneously injected mesenchymal stem cells in microvascular beds in rats

BACKGROUND

In this article, the authors investigated whether the prefabrication of an autologous pedicled flap by isolation from the surrounding with artificial skin substitutes would increase mesenchymal stem cell (MSC) seeding.

METHODS

Mesenchymal stem cells were isolated from human umbilical cords and were cultured and characterized by fluorescence-activated cell sorting. Oxacarbocyanine and its green fluorescence emission were used to label the MSCs population.Sixteen adult Wistar rats were randomized in 4 groups (n = 4 animals per group). In group 1, a prefabricated groin flap (GF) with skin substitutes was harvested without cell injection; in group 2, 1 million MSCs were injected subcutaneously in the area corresponding to the GF without flap harvesting; in Group 3, a prefabricated GF with skin substitutes was harvested and 1 million MSCs were injected subcutaneously; and in Group 4, a prefabricated GF with skin substitutes was harvested and 2 million MSCs were injected subcutaneously. All procedures were performed bilaterally in each animal. Animals were sacrificed 2 weeks after the surgery. Flap viability was then assessed by clinical inspection and histology, and seeding of MSCs was observed.

RESULTS

All flaps survived 2 weeks after the surgery. Oxacarbocyanine-labeled cells were found in all prefabricated flaps injected (Groups 3 and 4) in higher number in comparison with the group where subcutaneous injection without flap harvesting was performed (Group 2). This difference was statistically significant (P < 0.05).

CONCLUSIONS

Prefabricated skin flaps with skin substitutes may provide a useful vehicle for the implantation of MSCs to serve as an autologous microvascular bioscaffold.

Neurotherapeutic effect of cord blood derived CD45+ hematopoietic cells in mice after traumatic brain injury

Treatment of traumatic brain injury (TBI) is still an unmet need. Cell therapy by human umbilical cord blood (HUCB) has shown promising results in animal models of TBI and is under evaluation in clinical trials. HUCB contains different cell populations but to date, only mesenchymal stem cells have been evaluated for therapy of TBI. Here we present the neurotherapeutic effect, as evaluated by neurological score, using a single dose of HUCB-derived mononuclear cells (MNCs) upon intravenous (IV) administration one day post-trauma in a mouse model of closed head injury (CHI). Delayed (eight days post-trauma) intracerebroventricular administration of MNCs showed improved neurobehavioral deficits thereby extending the therapeutic window for treating TBI. Further, we demonstrated for the first time that HUCB-derived pan-hematopoietic CD45 positive (CD45(+)) cells, isolated by magnetic sorting and characterized by expression of CD45 and CD11b markers (96-99%), improved the neurobehavioral deficits upon IV administration, which persisted for 35 days. The therapeutic effect was in a direct correlation to a reduction in the lesion volume and decreased by pre-treatment of the cells with anti-human-CD45 antibody. At the site of brain injury, 1.5-2 h after transplantation, HUCB-derived cells were identified by near infrared scanning and immunohistochemistry using anti-human-CD45 and anti-human-nuclei antibodies. Nerve growth factor and vascular endothelial growth factor levels were differentially expressed in both ipsilateral and contralateral brain hemispheres, thirty-five days after CHI, measured by enzyme-linked immunosorbent assay. These findings indicate the neurotherapeutic potential of HUCB-derived CD45(+) cell population in a mouse model of TBI and propose their use in the clinical setting of human TBI.

Estimation of size of cord blood inventory based on high-resolution typing of HLAs

Methods for estimating the cord blood (CB) inventory size required vary according to the ethnic diversity of the HLA, degree of HLA matching and HLA-typing resolution. We estimated the CB inventory size required using 7190 stored CB units (CBU) and 2450 patients who were awaiting or underwent allogeneic hematopoietic stem cell transplantation. With high-resolution typing of HLA-A, B and DRB1, 94.6% of Korean patients could find CBUs in 100 000 CBUs with a 5/6 match, and 95.7% could find CBUs in 5000 CBUs with a 4/6 match. With low-resolution typing of HLA-A and B and high-resolution typing of leukocyte antigen-DRB1, 95% of patients could find CBUs in 50 000 CBUs with a 5/6 match, and 96.7% could find CBUs in 3000 CBUs  with a 4/6 match. With additional high-resolution typing for HLA-A and B, which could improve transplantation outcome, the size of the CB inventory would need to increase twofold for Koreans.

Myocardial regeneration of the failing heart

Human heart failure (HF) is one of the leading causes of morbidity and mortality worldwide. Currently, heart transplantation and implantation of mechanical devices represent the only available treatments for advanced HF. Two alternative strategies have emerged to treat patients with HF. One approach relies on transplantation of exogenous stem cells (SCs) of non-cardiac or cardiac origin to induce cardiac regeneration and improve ventricular function. Another complementary strategy relies on stimulation of the endogenous regenerative capacity of uninjured cardiac progenitor cells to rebuild cardiac muscle and restore ventricular function. Various SC types and delivery strategies have been examined in the experimental and clinical settings; however, neither the ideal cell type nor the cell delivery method for cardiac cell therapy has yet emerged. Although the use of bone marrow (BM)-derived cells, most frequently exploited in clinical trials, appears to be safe, the results are controversial. Two recent randomized trials have failed to document any beneficial effects of intracardiac delivery of autologous BM mononuclear cells on cardiac function of patients with HF. The remarkable discovery that various populations of cardiac progenitor cells (CPCs) are present in the adult human heart and that it possesses limited regeneration capacity has opened a new era in cardiac repair. Importantly, unlike BM-derived SCs, autologous CPCs from myocardial biopsies cultured and subsequently delivered by coronary injection to patients have given positive results. Although these data are promising, a better understanding of how to control proliferation and differentiation of CPCs, to enhance their recruitment and survival, is required before CPCs become clinically applicable therapeutics.

Umbilical cord blood expansion with nicotinamide provides long-term multilineage engraftment

BACKGROUND

Delayed hematopoietic recovery is a major drawback of umbilical cord blood (UCB) transplantation. Transplantation of ex vivo-expanded UCB shortens time to hematopoietic recovery, but long-term, robust engraftment by the expanded unit has yet to be demonstrated. We tested the hypothesis that a UCB-derived cell product consisting of stem cells expanded for 21 days in the presence of nicotinamide and a noncultured T cell fraction (NiCord) can accelerate hematopoietic recovery and provide long-term engraftment.

METHODS

In a phase I trial, 11 adults with hematologic malignancies received myeloablative bone marrow conditioning followed by transplantation with NiCord and a second unmanipulated UCB unit. Safety, hematopoietic recovery, and donor engraftment were assessed and compared with historical controls.

RESULTS

No adverse events were attributable to the infusion of NiCord. Complete or partial neutrophil and T cell engraftment derived from NiCord was observed in 8 patients, and NiCord engraftment remained stable in all patients, with a median follow-up of 21 months. Two patients achieved long-term engraftment with the unmanipulated unit. Patients transplanted with NiCord achieved earlier median neutrophil recovery (13 vs. 25 days, P < 0.001) compared with that seen in historical controls. The 1-year overall and progression-free survival rates were 82% and 73%, respectively.

CONCLUSION

UCB-derived hematopoietic stem and progenitor cells expanded in the presence of nicotinamide and transplanted with a T cell-containing fraction contain both short-term and long-term repopulating cells. The results justify further study of NiCord transplantation as a single UCB graft. If long-term safety is confirmed, NiCord has the potential to broaden accessibility and reduce the toxicity of UCB transplantation.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01221857.

FUNDING

Gamida Cell Ltd.

[Post-transplant cell immune reconstitution in humanized NOD/SCID mice]

OBJECTIVE

To investigate the cell immune reconstitution in non-obese diabetic/severe combined immunodeficient (NOD/SCID) mice by the transplantation of human umbilical cord blood (HUCB) CD34⁺; cells. Methods CD34⁺; cells were isolated from HUCB by magnetic activated cell sorting (MACS), and then were transplanted into NOD/SCID mice following the irradiation of sublethal doses via the lateral tail vein. Human CD45⁺; CD3⁺; CD56⁺; cell populations in the peripheral blood of mice were dynamically analyzed by flow cytometry (FCM) 4, 6, 8 and 10 weeks after transplantation. After 10 weeks, the expression of human ALU gene was detected by PCR in the bone marrow of mice, and the expressions of human CD3⁺; CD56⁺; cells were examined by immunohistochemical staining in the spleen tissues.

RESULTS

After irradiation, the nucleated cells and giant cells in the marrow cavity of NOD/SCID mice were reduced significantly or completely demolished. The effect of myeloablative pretreatment was ideal. Human CD45⁺; CD3⁺; CD56⁺; cells were found by FCM in the peripheral blood of all surviving mice in transplantation group 4, 6, 8, and 10 weeks after the transplantation. The population of the human lymphocytes varied over time, peaked at the 8th week, and remained at a high level later. At the 10th week, the human ALU sequence could be detected in the bone marrow of all surviving mice in transplantation group, and human CD3⁺; CD56⁺; cells could be observed in the spleen tissues. All mice which received no transplantation died within 2 weeks after irradiation.

CONCLUSION

The hu-SRC-NOD/SCID model was successfully established in irradiation-induced NOD/SCID mice by the transplantation of HUCB CD34⁺; cells, and its cell immune system was effectively rebuilt.

Feasibility of autologous cord blood cells for infants with hypoxic-ischemic encephalopathy

OBJECTIVE

To assess feasibility and safety of providing autologous umbilical cord blood (UCB) cells to neonates with hypoxic-ischemic encephalopathy (HIE).

STUDY DESIGN

We enrolled infants in the intensive care nursery who were cooled for HIE and had available UCB in an open-label study of non-cyropreserved autologous volume- and red blood cell-reduced UCB cells (up to 4 doses adjusted for volume and red blood cell content, 1-5 × 10(7) cells/dose). We recorded UCB collection and cell infusion characteristics, and pre- and post-infusion vital signs. As exploratory analyses, we compared cell recipients' hospital outcomes (mortality, oral feeds at discharge) and 1-year survival with Bayley Scales of Infant and Toddler Development, 3rd edition scores ≥85 in 3 domains (cognitive, language, and motor development) with cooled infants who did not have available cells.

RESULTS

Twenty-three infants were cooled and received cells. Median collection and infusion volumes were 36 and 4.3 mL. Vital signs including oxygen saturation were similar before and after infusions in the first 48 postnatal hours. Cell recipients and concurrent cooled infants had similar hospital outcomes. Thirteen of 18 (74%) cell recipients and 19 of 46 (41%) concurrent cooled infants with known 1-year outcomes survived with scores >85.

CONCLUSIONS

Collection, preparation, and infusion of fresh autologous UCB cells for use in infants with HIE is feasible. A randomized double-blind study is needed.

Intraarterial transplantation of human umbilical cord blood mononuclear cells is more efficacious and safer compared with umbilical cord mesenchymal stromal cells in a rodent stroke model

INTRODUCTION

Stroke is the second leading cause of death worldwide, claims six lives every 60 seconds, and is a leading cause of adult disability across the globe. Tissue plasminogen activator, the only United States Food and Drug Administration (FDA)-approved drug currently available, has a narrow therapeutic time window of less than 5 hours. In the past decade, cells derived from the human umbilical cord (HUC) have emerged as a potential therapeutic alternative for stroke; however, the most effective HUC-derived cell population remains unknown.

METHODS

We compared three cell populations derived from the human umbilical cord: cord blood mononuclear cells (cbMNCs); cord blood mesenchymal stromal cells (cbMSCs), a subpopulation of cbMNCs; and cord matrix MSCs (cmMSCs). We characterized these cells in vitro with flow cytometry and assessed the cells' in vivo efficacy in a 2-hour transient middle cerebral artery occlusion (MCAo) rat model of stroke. cbMNCs, cbMSCs, and cmMSCs were each transplanted intraarterially at 24 hours after stroke.

RESULTS

A reduction in neurologic deficit and infarct area was observed in all three cell groups; however, this reduction was significantly enhanced in the cbMNC group compared with the cmMSC group. At 2 weeks after stroke, human nuclei-positive cells were present in the ischemic hemispheres of immunocompetent stroke rats in all three cell groups. Significantly decreased expression of rat brain-derived neurotrophic factor mRNA was observed in the ischemic hemispheres of all three cell-treated and phosphate-buffered saline (PBS) group animals compared with sham animals, although the decrease was least in cbMNC-treated animals. Significantly decreased expression of rat interleukin (IL)-2 mRNA and IL-6 mRNA was seen only in the cbMSC group. Notably, more severe complications (death, eye inflammation) were observed in the cmMSC group compared with the cbMNC and cbMSC groups.

CONCLUSIONS

All three tested cell types promoted recovery after stroke, but cbMNCs showed enhanced recovery and fewer complications compared with cmMSCs.

[Successful treatment with azacitidine for a patient with relapsed myelodysplastic syndrome after cord blood transplantation]

A 72-year-old man visited our hospital in July 2009 with a major complaint of lightheadedness. Based on bone marrow aspiration, myelodysplastic syndrome (MDS), refractory anemia with excessive blast-2 was diagnosed. Complete remission (CR) was achieved after low-dose cytarabine and aclarubicin therapy. After two courses of low-dose cytarabine therapy, at the first CR, cord blood transplantation (CBT) was performed after reduced-intensity conditioning in January 2010. However, recurrence was found in September 2011. Azacitidine (AZA) was administered subcutaneously daily for either 7 or 5 days and repeated every 4 weeks at doses of 100 mg/day. During nine cycles of AZA treatment, no graft-versus-host disease was observed and no transfusions of red cells/platelet concentrate were required. As of 1 year after the relapse was detected, the patient remains alive with stable disease. As there are few reports on AZA treatment for patients with MDS who experience relapse after CBT, the efficacy of this approach remains unclear. Further clinical trials including dose, duration, and number of cycles of AZA for MDS patients who relapse after transplantation are required.

A single administration of human umbilical cord blood T cells produces long-lasting effects in the aging hippocampus

Neurogenesis occurs throughout life but significantly decreases with age. Human umbilical cord blood mononuclear cells (HUCB MNCs) have been shown to increase the proliferation of neural stem cells (NSCs) in the dentate gyrus (DG) of the hippocampus and the subgranular zone of aging rats (Bachstetter et al., BMC Neurosci 9:22, 2008), but it is unclear which fraction or combination of the HUCB MNCs are responsible for neurogenesis. To address this issue, we examined the ability of HUCB MNCs, CD4+, CD8+, CD3+, CD14+, and CD133+ subpopulations to increase proliferation of NSCs both in vitro and in vivo. NSCs were first grown in conditioned media generated from HUCB cultures, and survival and proliferation of NSC were determined with the fluorescein diacetate/propidium iodide and 5-bromo-2'-deoxyuridine incorporation assays, respectively. In a second study, we injected HUCB cells intravenously in young and aged Fisher 344 rats and examined proliferation in the DG at 1 week (study 2.1) and 2 weeks (study 2.2) postinjection. The effects of the HUCB MNC fractions on dendritic spine density and microglial activation were also assessed. HUCB T cells (CD3+, CD4+, and CD8+ cells) induced proliferation of NSCs (p < 0.001) and increased cell survival. In vivo, HUCB-derived CD4+ cells increased NSC proliferation at both 1 and 2 weeks while also enhancing the density of dendritic spines at 1 week and decreasing inflammation at 2 weeks postinjection. Collectively, these data indicate that a single injection of HUCB-derived T cells induces long-lasting effects and may therefore have tremendous potential to improve aging neurogenesis.

[Effect of compound danshen dripping pill combined with intravenous transplantation of human umbilical cord blood mononuclear cells on local inflammatory response in the myocardium of rabbits with acute myocardial infarction]

OBJECTIVE

To investigate effect of Compound Danshen Dripping Pill (CDDP) on the inflammatory response of the myocardium of acute myocardial infarction (AMI) rabbits, to observe the therapeutic effect of CDDP combined intravenous transplantation of human umbilical cord blood mononuclear cells (HUCBMCs) on inflammatory response, pro-inflammatory cytokine tumor necrosis factor alpha (TNF-alpha) , and heart function in the myocardium of AMI rabbits, and to explore the possible protective mechanisms of the combined therapy.

METHODS

The AMI model was successfully established by ligation of the left anterior coronary artery (LAD) in 40 healthy rabbits.Then they were randomly divided into four groups, i.e., the control group, the CDDP group, the transplantation group, and the combined group, 10 in each group. Rabbits in the control group received intravenous injection of 0.5 mL normal saline via ear vein within 24 h after AMI and then intragastric infusion of normal saline at 5 mL per day. Rabbits in the CDDP group received intravenous injection of 0.5 mL normal saline via ear vein within 24 h after AMI and then intragastric infusion of solution obtained by solving 270 mg CDDP in 5 mL normal saline per day. Rabbits in the transplantation group received intravenous injection of 0.5 mL normal saline labeled with green fluorescent protein (GFP) containing 3 x 10(7) of HUCBMCs via ear vein within 24 h after AMI and then intragastric infusion of normal saline at 5 mL per day. Rabbits in the combined group received intravenous injection of 0.5 mL normal saline labeled with GFP containing 3 x 10(7) of HUCBMCs via ear vein within 24 h after AMI and then intragastric infusion of solution obtained by solving 270 mg CDDP in 5 mL normal saline per day. At week 1 and 4 after treatment, cardiac function indices such as left ventricular fractional shorting (LVFS) and left ventricular ejection fraction (LVEF) were performed by echocardiography; the number of transplanted cells in the myocardium was found by GFP positive cells counted with fluorescence microscopy.The white blood cells in the myocardium stained with HE were determined by light microscope. The expressions of TNF-alpha protein in the myocardium were detected by immunohistochemical assay.

RESULTS

(1) Compared with the control group at week 1 and 4 after treatment, the LVEF and LVFS were significantly improved in the CDDP, transplantation, and combined groups (P < 0.05). The cardiac function was significantly improved in the combined group than in the CDDP group and the transplantation group (P < 0.05). But there was no statistical difference in the latter two groups. (2) Compared with the control group, the number of white blood cells and the expression of TNF-alpha protein decreased significantly in the CDDP, transplantation, and combined groups at week 1 and 4 respectively after treatment. The number of white blood cells and expressions of TNF-alpha protein were significantly lower in the combined group than in the CDDP group and the transplantation group (P <0.05). But there was no statistical difference in the latter two groups. (3) GFP-positive cells were found to be distributed in the peri-myocardial infarction area in the transplantation group and the combined group at week 1 and 4 after transplantation. Besides, the number of the GFP positive cells was much more in the combined group than in the transplantation group (P < 0.05).

CONCLUSIONS

The findings indicated that the combination of CDDP with intravenous transplantation of HUCBMCs in the treatment of AMI rabbits could elevate the survival rate of transplanted cells, and further improve the heart function. The possible mechanisms might be related to attenuating local inflammation of myocardium, and inhibiting enhanced expressions of pro-inflammatory cytokine TNF-alpha protein.

Human umbilical-cord-blood mononucleated cells enhance the survival of lethally irradiated mice: dosage and the window of time

The purpose of this study was to evaluate the window of time and dose of human umbilical-cord-blood (HUCB) mononucleated cells necessary for successful treatment of radiation injury in mice. Female A/J mice (27-30 weeks old) were exposed to an absorbed dose of 9-10 Gy of (137)Cs γ-rays delivered acutely to the whole body. They were treated either with 1 × 10(8) or 2 × 10(8) HUCB mononucleated cells at 24-52 h after the irradiation. The antibiotic Levaquin was applied 4 h postirradiation. The increased dose of cord-blood cells resulted in enhanced survival. The enhancement of survival in animals that received 2 × 10(8) HUCB mononucleated cells relative to irradiated but untreated animals was highly significant (P < 0.01). Compared with earlier studies, the increased dose of HUCB mononucleated cells, coupled with early use of an antibiotic, extended the window of time for effective treatment of severe radiation injury from 4 to 24-52 h after exposure.

Intra-arterial transplantation of human umbilical cord blood mononuclear cells in neonatal hypoxic-ischemic rats

Based on preclinical findings, cellular therapy has become a promising therapeutic approach for neonatal hypoxia-ischemia (HI). However, before translation into the clinical setting, new and effective routes of cell delivery must be determined. Intra-arterial (IA) delivery is an attractive route of cellular administration but has never been used in neonatal HI rats.

AIMS

In this study, we investigated the feasibility of IA transplantation of human umbilical cord blood (HUCB) mononuclear cells for the treatment of long-term behavior dysfunction and brain lesion after neonatal HI.

MAIN METHODS

Seven-day-old rats were subjected to a HI model and the animals received HUCB mononuclear cells into the left common carotid artery 24 h after HI insult.

KEY FINDINGS

At 9 weeks post-HI, intra-arterially transplanted HUCB mononuclear cells significantly improved learning and long-term spatial memory impairments when evaluated by the Morris water maze paradigm. There was no effect of neonatal HI insult or IA procedure on body weight and on motor coordination and balance when evaluated by the accelerating rotarod test. Cellular transplantation by the IA route did not restore neonatal HI-induced brain damage according to stereological volume assessment. Furthermore, HUCB mononuclear cells were tracked in the injured brain and peripheral organs of HI transplanted-rats by nested polymerase chain reaction analysis at different time points.

SIGNIFICANCE

Our findings contribute to the translational knowledge of cell based-therapy in neonatal HI and demonstrate for the first time that IA transplantation into rat pups is a feasible route for cellular delivery and prevents long-term cognitive deficits induced by experimental neonatal HI.

Umbilical cord blood transplantation using non-myeloablative conditioning: The Mexican experience

Twenty-eight children and adults underwent transplantation with allogeneic umbilical cord blood cells (UCB) using a non-ablative conditioning regimen; there were 15 males and 13 females. Seven patients were grafted because a non-malignant condition and 21 for a malignant disease. The median age was 8 years (range 4 months-72 years). Ten UCB were obtained from Mexican cord bloods banks, five cords were from compatible siblings and the remaining 13 cords were obtained from abroad. Median time to recover >0.5 x 10(9)/l granulocytes was 24 days (range 8-32 days), whereas median time to recover >20 x 10(9)/l platelets was 26 days (range 12-50 days). Twelve recipients never engrafted and recovered subsequently endogenous hematopoiesis. The non-engraftment rate was significantly higher in patients allografted for benign conditions (71%) than in those allografted for malignant conditions (28%). The median overall post-transplant survival (SV) was 33 months and the 73-months overall SV was 39%. The cumulative incidence of grade II-IV acute GVHD and grade III-IV GVHD for the entire cohort of patients were 14 and 7%, respectively. Additional studies are needed to define if non-myeloablative conditioning is preferable over conventional conditioning in the case of UCB allografting.

[Study on human umbilical cord mesenchymal stem cells transplantation in treatment of stress urinary incontinence in rats]

OBJECTIVE

To investigate the feasibility and effectiveness of human umbilical cord mesenchymal stem cells (HUCMSC) transplantation in the treatment of female stress urinary incontinence (SUI) in rats.

METHODS

The 14 female SD rats of SUI model were established by vaginal balloon dilation after birth and maintain this status for four hours bilateral ovariectomy were performed after two weeks and were routinely reared for two months, then 12 SUI rat model were made. Two months later, transfected with plasmid pEGFP-N1 of HUCMSC were injected into the region surrounding the urinary tract matched with saline injection as control group. To get genitourinary tissue after testing urodynamic indicators, and observe the pathological changes of the bladder, urethra and the surrounding tissue; fluorescent cell of the experimental groups specimens were observed by fluorescence microscope.

RESULTS

The leak point pressure(LPP) was (23.8 ± 4.2) mm Hg(1 mm Hg = 0.133 kPa) of the SUI rats. Transplanting mesenchymal stem cells of SUI rats, the positive rate of sneeze test was 1/6 in SUI group and 5/6 in control group, which reached statistical significance (P < 0.05); LPP was (30.6 ± 2.8) mm Hg in SUI group and (21.4 ± 7.0) mm Hg in control group, which reached statistical significance (P < 0.05) .In SUI rate model, connective tissue content were increased in urethra and the surrounding tissue and more fluorescent cell were observed.

CONCLUSIONS

A rat model of female SUI was established successfully through postpartum vaginal balloon dilation and bilateral ovariectomy. MSC can be survived and proliferated in the urethral and the surrounding tissue of injured rats, and improve the urodynamic indicators and the positive rate of sneeze test. Morphology shows renovation of the support structures around the urethra.

[Human umbilical cord blood mononuclear cell transplantation promotes long-term neurobehavioral functional development of newborn SD rats with hypoxic ischemic brain injury]

OBJECTIVE

To explore the effect of human umbilical cord blood mononuclear cells (UCBMC) promoting nerve behavior function and brain tissue recovery of neonatal SD rat with hypoxic ischemic brain injury (HIBI).

METHOD

A modified newborn rat model that had a combined hypoxic and ischemic brain injury as described by Rice-Vannucci was used, early nervous reflex, the Morris water maze and walking track analysis were used to evaluate nervous behavioral function, and brain MRI, HE staining to evaluate brain damage recovery.

RESULT

Newborn rat Rice-Vannucci model showed significant brain atrophy, obvious hemiplegia of contralateral limbs,e.g right step length [(7.67 ± 0.46) cm vs. (8.22 ± 0.50) cm, F = 1.494] and toe distance [(0.93 ± 0.06) cm vs. (1.12 ± 0.55) cm, F = 0.186] were significantly reduced compared with left side, learning and memory ability was significantly impaired compared with normal control group (P < 0.01); Cliff aversion [(8.44 ± 2.38) s vs.(14.22 ± 5.07) s, t = 4.618] and negative geotaxis reflex time [(7.26 ± 2.00) s vs. (11.76 ± 3.73) s, t = 4.755] on postnatal 14 days of HIBI+ transplantation group were significantly reduced compared with HIBI+NaCl group (P < 0.01) ; the Morris water maze experiment showed escape latency [ (23.11 ± 6.64) s vs. (34.04 ± 12.95) s, t = 3.356] and swimming distance [ (9.12 ± 1.21) cm vs.(12.70 ± 1.53) cm, t = 17.095] of HIBI+transplantation group were significantly reduced compared with those of HIBI+NaCl group (P < 0.01) ; the residual brain volume on postnatal 10 d [ (75.37 ± 4.53)% vs. (67.17 ± 4.08)%, t = -6.017] and 67 d [ (69.05 ± 3.58)% vs.(60.83 ± 3.69)%, t = -7.148]of HIBI+ transplantation group were significantly larger than those of HIBI+NaCl group (P < 0.01); After human UCBMC transplantation, left cortical edema significantly reduced and nerve cell necrosis of HIBI+ transplantation group is not obvious compared with HIBI+NaCl group.

CONCLUSION

Human UCBMC intraperitoneal transplantation significantly promoted recovery of injured brain cells and neurobehavioral function development.

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.

Autologus or allogenic uses of umbilical cord blood whole or RBC transfusion - a review

Once Umbilical Cord with Placenta considered a biological waste product and generally discarded after delivery but now cord blood has emerged as a viable source of hematopoietic stem cell transplantation. High-risk premature infants require red cell transfusions for anemia. A unique property of cord blood (CB) for its high content of immature hematopoietic progenitor cells (HPCs). Placental blood for autologous transfusions can be collected with aseptic precaution/sterilely into citrate-phosphate-dextrose and stored at 4°C. During storage for 8 days, the placental red cell content of adenosine triphosphate remained normal. The 2,3,-diphosphoglycerate concentration of cells stored beyond 8 days declined sharply. So we have to store umbilical cord blood (UCB) within 7 days for its best result. During storage, placental blood underwent an exchange of extra-cellular Na+ and K+, but no change in glutathione content. Hemolysis was less than 1 percent. Bacteriologic and fungal cultures remained sterile. These suggest that human placental blood can be collected safely and preserved effectively for autologous/allogenic transfusion therapy. In neonatal transfusion practice, efforts have been made to provide premature infants with autologous red blood cell (RBC), especially those born before 32 gestational weeks. In India no adverse transfusion effects were seen in a wide variety of patients that received (pooled) allogeneic fresh whole blood / UCB transfusions. The use of UCB for small volume allogeneic transfusions in anaemic children in Africa or in malaria endemic areas has also been proposed. A preclinical study showed that donation and transfusion of UCB would be acceptable to women living in Mombasa, Kenya. In view of the small volumes RBC per unit that can be collected, it is most likely that anaemic children need of a small volume of transfusions. In resource-restricted countries would benefit most from this easily available transfusion product.

[Optional protocols of hematopoietic stem cell expansion in vitro]

Hematopoietic stem cells (HSC) effectively and continuously renew a full spectrum of blood cell populations. Bone marrow and umbilical cord blood stem cells transplantation (SCT) restore hematopoietsis, when used in various hematological and oncohematological disorders in adults and children. However, wider clinical application of effective SCT-based approaches is limited by the low number of the primitive HSC in the available biospecimens. Development of effective protocols for HSC expansion in vitro is therefore necessary. In this review, a concept of bone marrow hematopoiesis niche being a complex cellular system is discussed; a comparative analysis of various methods for HSC expansion in vitro is provided. The review is illustrated by the authors own data supporting application of various feeder cell types for human HSC expansion in vitro.

Phase II trial of parathyroid hormone after double umbilical cord blood transplantation

Transplantation of 1 or 2 umbilical cord blood products is a useful alternative stem cell source. However, the limited number of stem cells in each infusion results in slow engraftment. In mouse models, administration of parathyroid hormone (PTH) is an effective way to enhance the ability of limited numbers of hematopoietic stem cells to support hematopoiesis. In this study, patients received either a myeloablative or a reduced-intensity double umbilical cord blood transplantation, followed by PTH at 100 μg/day for 28 days. Thirteen patients (median age, 42 years) were enrolled. All patients engrafted; the median time to neutrophil and platelet engraftment of >20 × 10(9) cells/L was 30 days and 61 days, respectively. The incidence of grade II-IV acute GVHD was 38.5% at day 100. Four deaths occurred before day 100, prompting early study closure. No patient who received a myeloablative regimen relapsed. Overall survival at 6 months after transplantation was 62%, and disease-free survival at 2 years was 39%. At the dose and schedule studied, there was no evidence that PTH influenced blood count recovery.

Enhancing engraftment of cord blood cells via insight into the biology of stem/progenitor cell function

Cord blood (CB) transplantation has been used over the last 24 years to treat patients with malignant and nonmalignant disorders. CB has its advantages and disadvantages compared with other sources of hematopoietic stem cells (HSCs) and hematopoietic progenitor cells (HPCs) for transplantation. More knowledge of the cytokines and intracellular signaling molecules regulating HSCs and HPCs could be used to modulate these regulators for clinical benefit. This review provides information about the general field of CB transplantation and about studies from the author's laboratory that focus on regulation of HSCs and HPCs by CD26/DPPIV, SDF-1/CXCL12, the Rheb2-mTOR pathway, SIRT1, DEK, cyclin-dependent kinase inhibitors, and cytokines/growth factors. Cryopreservation of CB HSCs and HPCs is also briefly discussed.

Neuroglial activation and Cx43 expression are reduced upon transplantation of human umbilical cord blood cells after perinatal hypoxic-ischemic injury

Glial cells play a crucial role in the pathomechanism of perinatal hypoxic-ischemic brain injury (HI) and are involved in the maintenance of a chronic state of inflammation that causes delayed neuronal damage. Activation of astrocytes is one factor prolonging brain damage and contributing to the formation of a glial scar that limits neuronal plasticity. In this context, the major astrocytic gap junction protein Connexin 43 (Cx43) has been ascribed various functions including regulation of astrocytic migration and proliferation. Here, we investigate glial responses like microglia/macrophages and astrocytic activation in a rat model of neonatal HI and characterize changes of these parameters upon transplantation of human umbilical cord blood cells (hUCB). As an alleviation of motor function in lesioned rats has previously been described in transplanted animals, we analyze the putative correlation between motor function and glial activation over time. The lesion-induced impairment of motor function, assessed by forelimb use bias, muscle strength and distal spasticity, was alleviated upon transplantation of hUCB short and long term. HI induced an acute inflammatory reaction with activation of microglia/macrophages and reactive astrogliosis associated with perilesional upregulation of Cx43 that slowly declined during the chronic post-ischemic phase. hUCB transplantation accelerated the regression of inflammatory events, narrowed the perilesional astrocytic wall and led to a downregulation of the investigated astrocytic proteins. Thus, in the immature brain, hUCB may indirectly reduce secondary cell death upon hypoxia-ischemia and facilitate post-ischemic plasticity through the attenuation of reactive gliosis. This article is part of a Special Issue entitled Electrical Synapses.

[Unrelated umbilical cord blood transplantation with TBI/Ara-c/CY non-ATG conditioning regimen for adults with hematologic malignancies]

OBJECTIVE

To retrospectively analyze the curative efficacy of umbilical cord blood transplantation (UCBT) with improved myeloablative conditioning regimen (total body irradiation (TBI)/cytosine arabinoside (Ara-c)/cyclophosphamide (CY) without antithymocyte globulin (ATG)) in adult patients with hematological malignancies.

METHODS

Forty consecutive adult patients with hematological malignancies received improved myeloablative unrelated CBT at a single center from September 2006 to May 2011. Their average age was (23 ± 6) years and the average weight (58 ± 9) kg. Thirty-five (87.5%) patients were high-risk and 15 (37.5%) at the advanced disease status at pre-transplantation. They received 1 (n = 23) or 2 (n = 17) cord blood units. Seventy-five percent of them were transplanted with 1/2-human leukocyte antigen mismatched unit. The conditioning regimen consisted of 12 Gy TBI, granulocyte colony-stimulating factor (G-CSF) plus Ara-c and CY without ATG. All patients received a combination of cyclosporine (CsA) and mycophenolate mofetil (MMF) for the prophylaxis of graft-versus-host disease (GVHD).

RESULTS

For the entire group of patients, the average cell doses infused were (4.1 ± 1.1)×10⁷ total nucleated cells/kg and (2.4 ± 1.0)×10⁵ CD34(+) cells/kg. All patients acquired engraftment with an implantation rate of 100%. The average time of absolute neutrophil count (ANC) ≥ 0.5×10⁹/L was (20 ± 5) days and the average time of platelet ≥ 20×10⁹/L was(38 ± 12) days. Acute GVHD occurred in 23 patients (57.5%) and 4 (10.0%) were of grade III-IV. Chronic GVHD occurred in 22.9% (8/35) evaluable patients. Relapse occurred in 12.5% (5/40) patients. During a median follow-up period of 19.8 (range 4.6 - 55.0) months, the transplantation-related mortality was 15.0% (6/40) within 100 days and 35.0% (14/40) within 1 year. The main causes of mortality were pneumonia and severe acute GVHD. Two-year overall survival (OS) or disease-free survival was 58.8% and 58.8%, respectively. Two-year OS for patients with advanced or complete remission disease was 48.6% and 63.8%, respectively.

CONCLUSIONS

The TBI/Ara-c/CY myeloablative conditioning regimen is well-tolerated and capable of establishing sustained donor cell engraftment and decreasing the risks of transplant-related death in adults with hematologic malignancies. For the high-risk and advanced patients, it may reduce the occurrences of relapse and chronic GVHD.

Reduced-intensity conditioning in unrelated donor cord blood transplantation for familial hemophagocytic lymphohistiocytosis

Familial hemophagocytic lymphohistiocytosis (FHL) is a disorder of immune homeostasis characterized by fever, cytopenias, hepatosplenomegaly, and coagulopathy. We studied the outcomes of 13 FHL patients who underwent the first unrelated cord blood transplantation (UCBT) after non-myeloablative conditionings. The major regimen consisted of fludarabine (FLU; n = 12)+melphalan (MEL; n = 11)± low-dose total body irradiation (TBI 2-4 Gy; n = 6). The median age at presentation and period to UCBT were 6 and 5 months, respectively. Central nervous system (CNS) disease developed in one infant at diagnosis, and in two others until UCBT. HLH activity was controlled in all but one at the time of UCBT. Ten patients had early engraftment on median day 21 with no grade >2 treatment-related toxicity and two controllable grade >2 acute GVHD. Two patients with early rejection successfully underwent subsequent UCBT after myeloablative conditioning. Two others had late graft failure following mixed donor chimerism. Two deaths occurred from HLH; early liver failure and late CNS disease. Of 11 FLU+MEL-conditioned patients, the frequency of disease-free complete engraftment was higher for MEL (≥120 mg/m(2) )+TBI, or high-dose MEL (180 mg/m(2) ) than for others (83% vs. 25%, p = 0.036). The FLU+MEL-based non-myeloablative regimen was acceptable for FHL infants undergoing UCBT, although further studies will be needed for confirmation.

The dose-response effect of acute intravenous transplantation of human umbilical cord blood cells on brain damage and spatial memory deficits in neonatal hypoxia-ischemia

Despite the beneficial effects of cell-based therapies on brain repair shown in most studies, there has not been a consensus regarding the optimal dose of human umbilical cord blood cells (HUCBC) for neonatal hypoxia-ischemia (HI). In this study, we compared the long-term effects of intravenous administration of HUCBC at three different doses on spatial memory and brain morphological changes after HI in newborn Wistar rats. In addition, we tested whether the transplanted HUCBC migrate to the injured brain after transplantation. Seven-day-old animals underwent right carotid artery occlusion and were exposed to 8% O(2) inhalation for 2 h. After 24 h, randomly selected animals were assigned to four different experimental groups: HI rats administered with vehicle (HI+vehicle), HI rats treated with 1×10(6) (HI+low-dose), 1×10(7) (HI+medium-dose), and 1×10(8) (HI+high-dose) HUCBC into the jugular vein. A control group (sham-operated) was also included in this study. After 8 weeks of transplantation, spatial memory performance was assessed using the Morris water maze (MWM), and subsequently, the animals were euthanized for brain morphological analysis using stereological methods. In addition, we performed immunofluorescence and polymerase chain reaction (PCR) analyses to identify HUCBC in the rat brain 7 days after transplantation. The MWM test showed a significant spatial memory recovery at the highest HUCBC dose compared with HI+vehicle rats (P<0.05). Furthermore, the brain atrophy was also significantly lower in the HI+medium- and high-dose groups compared with the HI+vehicle animals (P<0.01; 0.001, respectively). In addition, HUCBC were demonstrated to be localized in host brains by immunohistochemistry and PCR analyses 7 days after intravenous administration. These results revealed that HUCBC transplantation has the dose-dependent potential to promote robust tissue repair and stable cognitive improvement after HI brain injury.

Trends in cord blood banking

BACKGROUND

Umbilical cord blood (UCB) is a source of hematopoietic precursor cells for transplantation. The creation of UCB banks in 1992 led to the possibility of storing units of UCB for unrelated transplants. The distribution of cell contents in historical inventories is not homogenous and many units are not, therefore, suitable for adults. The aim of this study was to analyse our UCB bank inventory, evaluate the units released for transplantation and calculate the cost of the current process per unit of UCB stored.

METHODS

Three study periods were defined. In the first period, from January 1996 to January 2006, the total nucleated cell (TNC) count acceptable for processing was 4-6×10(8) and a manual processing system was used. In the second period, from October 2006 to July 2010, processing was automated and the acceptable TNC count varied from 8-10×10(8). In the third period, from January 2009 to June 2010, an automated Sepax-BioArchive procedure was used and the accepted initial TNC count was >10×10(8). Within each period the units were categorised according to various ranges of cryopreserved TNC counts in the units: A, >16.2×10(8); B1, from 12.5-16.1×10(8); B2, from 5.2-12.4×10(8); and C, <5.1×10(8).

RESULTS

The third period is best representative of current practices, with homogenous TNC acceptance criteria and automated processing. In this period 15.7% of the units were category A and 25.5% were category B. Overall, the mean TNC count of units released for transplantation was 14×10(8) (range, 4.6×10(8) to 36.5×10(8)). The cost of the processed UCB in 2009 was 720.41 euros per unit.

CONCLUSION

An UCB bank should store units of high-quality, in terms of the TNC count of units issued for transplantation, have a training programme to optimise the selection of donors prior to delivery, use similar volume reduction systems and homogenous recovery indices, express its indicators in the same units, use validated analytical techniques, and bear in mind ethnic minorities.

In vivo MRI of intraspinally injected SPIO-labelled human CD34+ cells in a transgenic mouse model of ALS

BACKGROUND/AIM

Administration of stem cells is a promising novel approach for treatment of neurodegenerative diseases. For in vivo monitoring of transplanted cells, non-invasive imaging modalities are needed. In this study we determined the tracking efficiency of a superparamagnetic iron oxide (SPIO)-labelled canine cell line (MTH53A) in vitro as well as the human CD34(+) umbilical cord blood stem cells (hUCBCs) in vitro and in vivo efficiency by magnetic resonance imaging (MRI).

MATERIALS AND METHODS

SPIO-labelled MTH53A cells and hUCBCs were scanned in agar gel phantoms at 1.0 T or 7.0 T. For in vivo detection, 100,000 labelled hUCBCs were injected into the spinal cord of a transgenic amyotrophic lateral sclerosis (ALS) mouse and scanned at 7.0 T.

RESULTS

In vitro, 100,000 MTH53A cells and 250,000 hUCBCs were visible at 1.0 T. Scanning with 7.0 T revealed 25,000 detectable MTH53A cells. In vivo, 7.0 T MRI showed clear signals of 100,000 implanted cells.

CONCLUSION

MRI combined with SPIO nanoparticles provides valuable potential for non-invasive, non-toxic in vivo tracking of cells implanted into the spinal cord.

Hematopoietic stem cell transplantation in children with leukemia: a single institution experience with respect to donors

Aim of this study was to compare the outcomes of transplantation by donor source and to help select the best alternative donor in children with leukemia. Donor sources included matched related donor (MRD, n = 35), allele-matched unrelated donor (M-UD, n = 10) or -mismatched (MM)-UD (n = 13) or unrelated umbilical cord blood (UCB, n = 11). UCB group had a significantly higher incidence of grade II-IV acute graft versus host disease (MRD, 11.8%; M-UD, 30.0%; MM-UD, 15.4%, UCB, 54.4%, P = 0.004) but there was no difference in incidence of chronic graft versus host disease between 4 groups. The 5-yr leukemia-free survival (LFS) was 76.7%, 60.0%, 69.2%, and 45.5%, respectively (P = 0.128). MRD group showed higher LFS rate than UCB group (P = 0.022). However, LFS of M-UD and MM-UD together (65.2%) was not different from that of MRD group (76.7%, P = 0.325), or from that of UCB (45.5%, P = 0.190). The relapse incidence at 5 yr was 17.1%, 20.0%, 15.4%, and 0%, respectively (P = 0.460). The 100-day treatment-related mortality was 2.9%, 20.0%, 7.7%, and 36.4%, respectively (P = 0.011). Despite the limitations of small number of patients, unrelated donor transplants including even allele-mismatched ones, seem to be as effective in children with leukemia lacking suitable relative donors. Also, UCB transplant may serve as another possible option in urgent transplants.

[Recent advances in cord blood stem cell transplantation]

Cord blood stem cells are recognized as alternative donors for patients without HLA matched sibling donors in allogeneic stem cell transplantation, while limited number of stem cells are still associated with delayed or failed engraftment. To overcome this issue, clinical trials including reduced-intensity conditioning, double units transplantation, intrabone marrow injection as well as infusion of ex vivo expanded regulatory T cells have been performed. Chimerism analysis by multicolor flow cytometry is also valuable in monitoring the engraftment process. Future studies will test the potential application of cord blood stem cells to non-hematological disorders.

Family-directed umbilical cord blood banking

Umbilical cord blood transplantation from HLA-identical siblings provides good results in children. These results support targeted efforts to bank family cord blood units that can be used for a sibling diagnosed with a disease which can be cured by allogeneic hematopoietic stem cell transplantation or for research that investigates the use of allogeneic or autologous cord blood cells. Over 500 patients transplanted with related cord blood units have been reported to the Eurocord registry with a 4-year overall survival of 91% for patients with non-malignant diseases and 56% for patients with malignant diseases. Main hematologic indications in children are leukemia, hemoglobinopathies or inherited hematologic, immunological or metabolic disorders. However, family-directed cord blood banking is not widely promoted; many cord blood units used in sibling transplantation have been obtained from private banks that do not meet the necessary criteria required to store these units. Marketing by private banks who predominantly store autologous cord blood units has created public confusion. There are very few current validated indications for autologous storage but some new indications might appear in the future. Little effort is devoted to provide unbiased information and to educate the public as to the distinction between the different types of banking, economic models and standards involved in such programs. In order to provide a better service for families in need, directed-family cord blood banking activities should be encouraged and closely monitored with common standards, and better information on current and future indications should be made available.

Milestones in umbilical cord blood transplantation

Since the first human cord blood transplant, performed in 1988, cord blood banks have been established worldwide for collection and cryopreservation of cord blood for allogeneic hematopoietic stem cell transplant. Umbilical cord blood (UCB) has now become one of the most commonly used source of hematopoietic stem cells for allogeneic transplantation. Today a global network of cord blood banks and transplant centers has been established for a common inventory with an estimated 600,000 UCB have been banked and more than 20,000 UCB units distributed worldwide for adults and children with severe hematological diseases. Several studies have shown that the number of cells is the most important factor for engraftment while some degree of HLA mismatches is acceptable. The absence of ethical concern, and the unlimited supply of cells explain the increasing interest of using cord blood for developing regenerative medicine.

[Actions of keratinocyte growth factor in leukemic mice allogeneic umbilical cord blood cell transplantation]

OBJECTIVE

To explore the actions of keratinocyte growth factor (KGF) in leukemic mice allogeneic umbilical cord blood cell transplantation (UCBT) and elucidate its mechanism.

METHODS

Peripheral blood drawn from the litters of C57BL/6 females was used as umbilical cord blood (UCB) graft. BALB/c mice were randomly divided into 7 groups (n = 12 each). The grouping was as follows. Control group 1, inoculated with leukemia. Control group 2, inoculated with leukemia at -4 d and total body irradiation (TBI) treatment. Control group 3, TBI treatment and reconstituted with 2 × 10(6) UCB-TNCs. Control group 4, injected with PBS subcutaneously, TBI treatment and reconstituted with UCB-TNCs with platelet transfusion. Control group 5, inoculated with leukemia, injected with PBS subcutaneously, TBI treatment and reconstituted with UCB-TNCs with platelet transfusion. Experiment group 1, injected with KGF subcutaneously, TBI treatment and reconstituted with UCB-TNCs with platelet transfusion. Experiment group 2, inoculated with leukemia, injected with KGF subcutaneously, TBI treatment and reconstituted with UCB-TNCs with platelet transfusion. The survival status, pathohistological changes, splenic lymphoid cell subsets and thymic output post-UCBT were compared between groups.

RESULTS

The survival time of control group 1 was (11.1 ± 1.5) days and all died of leukemia. The survival time of control group 2 was (11.5 ± 2.5) days and all died of aplasia. Five of 12 mice of control group 3 survived for 100 days and 7 mice died of visceral hemorrhage. Four of 12 mice of control group 5 survived for 100 days and 8 mice died of leukemia with a survival rate of 33.3%. Nine of 12 mice of experiment group 2 survived for 100 days and 3 mice died of leukemia with a survival rate of 75.0%. The survival was prolonged in experiment group 2 mice as compared with that of control group 5 mice (χ² = 4.996, P = 0.0254). The splenic T, NK and B cell counts in control group 4 mice at +35 d were (9.32 ± 0.48) × 10⁶, (1.59 ± 0.11) × 10⁶ and (18.74 ± 2.01) × 10⁶ respectively. While in group 6 mice at +35 d were (13.20 ± 1.14) × 10⁶, (1.75 ± 0.12) × 10⁶ and (20.36 ± 0.86) × 10⁶ respectively. The counts of T cell and NK cell of group 6 were higher than those of group 4 (both P < 0.05). The level of signal joint T-Cell receptor excision circles (sjTRECs) in control group 4 mice was (167 ± 17) copies per 10⁵ cells while that of experiment group 1 mice (228 ± 24) copies per 10⁵ cells. They were higher than that of control mice (P = 0.002).

CONCLUSION

Hematopoietic stem/precursor cells are abundant in full-term murine fetal peripheral blood. The infusion of KGF reduces the post-UCBT relapse of leukemia through the enhancement of thymic output.

Long-term outcomes in adults with leukemia treated with transplantation of two unrelated umbilical cord blood units

BACKGROUND

Wide application of umbilical cord blood transplantation (UCBT) in adult patients is limited by low cell-dose available in one umbilical cord blood (UCB) unit. The aim of this study was to investigate the safety and long-term outcomes of UCBT from unrelated donors in adult and adolescent patients with leukemia.

METHODS

Thirteen patients with leukemia received double-unit UCBT with human leukocyte antigen (HLA) mismatched at 0 - 2 loci. We analyzed the engraftment, graft-versus-host disease (GVHD) and survival.

RESULTS

Twelve evaluable patients (92.3%) had neutrophil and platelet engraftment at a median of 21 days (range, 16-38 days) and 34 days (range, 25 - 51 days), respectively. At day 30, engraftment was derived from one donor in 8 patients (66.7%, 95%CI 40.0% - 93.4%), and from both donors in 4 patients (33.3%, 95%CI 6.7% - 60.0%) with 1 unit predominated. Unit with larger nucleated cell (NC) dose would predominate in engraftment (P = 0.039), whereas CD34(+) cell dose or HLA-match failed to demonstrate any relationship with unit predominance. Only one patient developed grade II acute graft-versus-host disease (aGVHD). Chronic GVHD (cGVHD) was observed in 2 of 11 patients who survived more than 100 days, and both were limited. The median follow-up after transplantation for the 13 patients was 45 months (range 1.5 - 121.0 months) and 72 months (range 41.0 - 121.0 months) for the 8 alive and with full donor chimerism. The 5-year cumulative disease free survival (DFS) was (61.5 ± 13.5)%. Of the 13 patients, 5 patients died in 1 year and 1-year transplantation related mortality (TRM) was 23.1% (95%CI 0.2% - 46.0%).

CONCLUSION

Double-unit UCBT from unrelated donors with HLA-mismatched at 0-2 loci may overcome the cell-dose barrier and be feasible for adults and adolescents with leukemia.

[Analysis of post-thaw infused cell dose for predicting engraftment after unrelated cord blood transplantation]

This study was purposed to investigate the role of post-thaw infused donor cells for predicting engraftment and hematopoietic reconstitution after unrelated cord blood transplantation (UCBT). The retrospective analysis was performed on clinical data of 97 children with malignant or non-malignant diseases received single unit UCBT from August 1999 to April 2010. The impact of pre-freezing and post-thaw cell dose of total nucleated cells (TNC), CD34(+) cells and colony-forming units-granulocyte/macrophage (CFU-GM) on engraftment and hematological recovery after UCBT was analyzed. Unrelated donors were from Guangzhou cord blood bank (GZCBB) entirely. The results indicated that the pre-freezing TNC (/kg) (mean ± SD: 7.65 × 10⁷ ± 4.26 × 10⁷; median: 6.34 × 10⁷), CD34(+)cells (/kg) (mean ± SD: 4.64 × 10(5) ± 4.47 × 10⁵; median: 3.03 × 10⁵) and CFU-GM (/kg) (mean ± SD: 0.79 × 10⁵ ± 1.09 × 10⁵; median: 0.57 × 10⁵) showed a good correlation with their post-thaw counterparts including TNC(/kg) (mean ± SD: 6.98 × 10⁷ ± 4.12 × 10⁷; median: 6.00 × 10⁷), CD34(+)cells (/kg)(Mean ± SD: 6.86 × 10⁵ ± 8.56 × 10⁵; Median: 4.17 × 10⁵), and CFU-GM (/kg) (mean ± SD: 0.52 × 10⁵ ± 0.52 × 10⁵; median: 0.39 × 10⁵) (r = 0.952, p < 0.001; r = 0.794, p < 0.001; r = 0.478, p < 0.001). Either the pre-freezing or post-thaw number of infused CFU-GM was significant higher in patients who achieved engraftment (n = 70) than those who suffered graft failure (n = 22) (p = 0.023 and 0.011, respectively), but no significant difference of TNC and CD34(+) cells dose (pre-freezing or post-thaw) were found between these two groups. Pre-freezing CFU-GM, TNC, CD34(+) cell dose negatively correlated with the time of neutrophil engraftment (r = -0.285, p = 0.018; r = -0.396, p = 0.002; r = -0.373, p = 0.002), as well as the post-thaw number of TNC and CD34(+) cells (r = -0.260, p = 0.031; r = -0.483, p < 0.001), whereas only pre-freezing CD34(+) cells showed a significant correlation with platelet engraftment time (r = -0.352, p = 0.013). It is concluded that the CFU-GM amount is useful for predicting engraftment of UCBT, while pre-freezing hematopoietic cell doses show superior correlation with the speed of engraftment and hematopoietic reconstitution than their post-thaw counterparts in pediatric recipients, suggesting that it is essential to perform hematopoietic potency assay on each cord blood unit prior to listing or release for administration.

Insights into the biology of cord blood stem/progenitor cells

OBJECTIVES

To review information on cord blood banking and transplantation with respect to the author's studies, and in context of this field of investigation.

RESULTS

Cord blood transplantation has been successfully used to treat a number of malignant and non-malignant disorders. However, this technique is still associated with limited numbers of cells for transplantation, and with delayed engraftment of neutrophils and platelets. The field of cord blood transplantation will benefit from enhanced and mechanistically based information on haematopoietic stem cell function and potential means to enhance its effectiveness are reviewed. This includes notions concerning possibility of retrieving more cells from the placenta and cord blood, to expand haematopoietic stem cells ex vivo and to increase efficiency of homing and engraftment of these cells. Also discussed are cryopreservation and long-term storage of cord blood haematopoietic and progenitor cells, and new laboratory findings and animal studies for non-haematopoietic uses of cord blood.

How I treat: the selection and acquisition of unrelated cord blood grafts

Use of unrelated donor cord blood (CB) as an alternative stem cell source is increasing, and yet there is little information to guide transplant centers in the unique aspects of the search and selection of CB grafts. There is no mechanism to easily access the global inventory of CB units, nor is the product information provided by all banks standardized. To address these challenges, this manuscript reviews the logistics of the search, selection process, and acquisition of CB grafts as practiced by our center. Topics include who should be considered for a CB search, how to access the global CB inventory, and how to balance total nucleated cell dose and human leukocyte antigen match in unit selection. We discuss aspects of unit quality and other graft characteristics (processing methods, unit age, availability of attached segments, infectious disease, and hemoglobinopathy screening) to be considered. We incorporate these considerations into a unit selection algorithm, including how to select double-unit grafts. We also describe how we plan for unit shipment and the role of backup grafts. This review aims to provide a framework for CB unit selection and help transplantation centers perform efficient CB searches.

Engraftment of unrelated cord blood after reduced-intensity conditioning regimen in children with refractory neuroblastoma: a feasibility trial

Relapsed or refractory neuroblastoma is uniformly fatal. We hypothesized that allogeneic response could provide a platform for immunotherapy in neuroblastoma. We therefore undertook a pilot trial of unrelated cord blood transplantation after reduced intensity conditioning regimen (RIC) in children with relapsed neuroblastoma to assess engraftment and tolerability in this heavily pretreated population. The RIC included CY (50 mg/kg, day -6), fludarabine (40 mg/m(2), days -6 to -2), total body irradiation (200 cGy, day -1), and rabbit anti-thymocyte globulin (2.5 mg/kg, days -3 to -1). Six patients were enrolled: four were in partial responsive relapse, one with a mixed response and one in refractory relapse. All patients tolerated the regimen well and had donor engraftment with full neutrophil and plt recovery (median time 12 and 35 days, respectively). One patient never experienced neutropenia and another did not need plt transfusions. All patients progressed after transplant (median time 55 days, 26-180 days). Natural killer (NK) cell counts were normal within 2 months, whereas T-cell recovery was slower. In conclusion, unrelated cord blood engrafts after RIC in children with refractory neuroblastoma. Future research should be aimed at transplanting patients with minimal residual disease, using less intensive immunosuppression and adding NK-cell based post transplant immunotherapy.

Umbilical cord blood transplantation for children with thalassemia and sickle cell disease

We examined the efficacy of unrelated cord blood (CB) transplantation in children with thalassemia (n = 35) and sickle cell disease (n = 16), using data reported to 3 registries. Donor-recipient pairs were matched at HLA-A and -B (antigen level) and DRB1 (allele level) in 7 or HLA mismatched at 1 (n = 18), 2 (n = 25), or 3 loci (n = 1). Transplant conditioning was myeloablative (n = 39) or reduced intensity (n = 12). Neutrophil recovery with donor chimerism was documented in 24 patients; 11 patients developed grade II-IV acute graft-versus-host disease (aGVHD) and 10 patients, chronic GVHD (cGVHD). Overall survival (OS) and disease-free survival (DFS) were 62% and 21% for thalassemia and 94% and 50% for sickle cell disease (SCD), respectively. In multivariate analysis, engraftment rate (hazard ratio [HR] 2.2, P = .05) and DFS (HR 0.4, P = .01) were higher with cell dose >5 × 10(7)/kg. The 2-year probability of DFS was 45% in patients who received grafts with cell dose >5 × 10(7)/kg and 13% with lower cell dose. Primary graft failure was the predominant cause of treatment failure occurring in 20 patients with thalassemia and 7 patients with SCD. Primary graft failure was fatal in 5 patients with thalassemia. These results suggest that only CB units containing an expected infused cell dose >5 × 10(7)/kg should be considered for transplantation for hemoglobinopathy.

Double cord blood transplantation: extending the use of unrelated umbilical cord blood cells for patients with hematological diseases

Unrelated umbilical cord blood (UCB) has been widely used to treat patients lacking a well-matched HLA donor. Cell dose is a critical determinant of outcomes in cord blood transplantation, limiting the use of this strategy for low body weight patients. To overcome this limitation, infusion of two partially HLA-matched cord units was adopted as a new strategy. Since 2005, number of adult patients treated with UCB transplant is increased due to the higher number of cells available using two units and to the feasibility of reduced intensity conditioning regimen, extending successfully this strategy to heavier patients or for those with co-morbidities. Approximately 993 adults with hematological diseases have been transplanted with double UCB graft, and reported to Eurocord registry from 1999 to 2010. This article reviews the state of art and future directions with double umbilical cord blood units as a source of hematopoietic stem cells for transplantation.