How old is too old? In vivo engraftment of human peripheral blood stem cells cryopreserved for up to 18 years-implications for clinical transplantation and stability programs

BACKGROUND Peripheral blood stem cells(PBSC)are commonly cryopreserved awaiting clinical use for hematopoietic stem cell transplant.Long term cryopreservation is commonly defined as five years or longer,and limited data exists regarding how long PBSC can be cryopreserved and retain the ability to successfully engraft.Clinical programs,stem cell banks,and regulatory and accrediting agencies interested in product stability would benefit from such data.Thus,we assessed recovery and colony forming ability of PBSC following long-term cryopreservation as well as their ability to engraft in NOD/SCID/IL-2 Rγnull(NSG)mice.AIM To investigate the in vivo engraftment potential of long-term cryopreserved PBSC units.METHODS PBSC units which were collected and frozen using validated clinical protocols were obtained for research use from the Cellular Therapy Laboratory at Indiana University Health.These units were thawed in the Cellular Therapy Laboratory using clinical standards of practice,and the pre-freeze and post-thaw characteristics of the units were compared.Progenitor function was assessed using standard colony-forming assays.CD34-selected cells were transplanted into immunodeficient mice to assess stem cell function.RESULTS Ten PBSC units with mean of 17 years in cryopreservation(range 13.6-18.3 years)demonstrated a mean total cell recovery of 88%±12%(range 68%-110%)and post-thaw viability of 69%±17%(range 34%-86%).BFU-E growth was shown in 9 of 10 units and CFU-GM growth in 7 of 10 units post-thaw.Immunodeficient mice were transplanted with CD34-selected cells from four randomly chosen PBSC units.All mice demonstrated long-term engraftment at 12 wk with mean34%±24%human CD45+cells,and differentiation with presence of human CD19+,CD3+and CD33+cells.Harvested bone marrow from all mice demonstrated growth of erythroid and myeloid colonies.CONCLUSION We demonstrated engraftment of clinically-collected and thawed PBSC following cryopreservation up to 18 years in NSG mice,signifying likely successful clinical transplantation of PBSC following long-term cryopreservation.

Transplantation of mesenchymal stem cells from human umbilical cord versus human umbilical cord blood for peripheral nerve regeneration

BACKGROUND： Mesenchymal stem cells （MSCs） appear to be a good alternative to Schwann cells in the treatment of peripheral nerve injury. Fetal stem cells, like umbilical cord blood （UCB） and umbilical cord （UC） stem cells, have several advantages over adult stem cells. OBJECTIVE： To assess the effects of UC-derived MSCs （UCMSCs） and UCB-derived MSCs （UCBMSCs） in repair of sciatic nerve defects. DESIGN, TIME AND SETTING： A randomized controlled animal experiment was performed at the laboratory of Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, from July to December 2009. MATERIALS： UCMSCs were provided by the Research Institute of Biotechnology, Dongguk University. UCBMSCs were provided by the Laboratory of Stem Cells and Tumor Biology, College of Veterinary Medicine, Seoul National University. Dulbecco＇s modified Eagle＇s medium （DMEM） was purchased from Gibco-BRL, USA. METHODS： Seven-week-old Sprague-Dawley rats were randomly and evenly divided into three groups： DMEM, UCBMSCs, and UCMSCs. A 10-mm defect in the left sciatic nerve was constructed in all rats. DMEM （15 μL） containing 1×10^6 UCBMSCs or UCMSCs was injected into the gap between nerve stumps, with the surrounding epineurium as a natural conduit. For the DMEM group, simple DMEM was injected. MAIN OUTCOME MEASURES： At 7 weeks after sciatic nerve dissection, dorsal root ganglia neurons were labeled by fluorogold retrograde labeling. At 8 weeks, electrophysiology and histomorphometry were performed. At 2, 4, 6, and 8 weeks after surgery, sciatic nerve function was evaluated using gait analysis. RESULTS： The UCBMSCs group and the UCMSCs group exhibited similar sciatic nerve function and electrophysiological indices, which were better than the DMEM group, as measured by gait analysis （P 〈 0.05）. Fluorogold retrograde labeling of sciatic nerve revealed that the UCBMSCs group demonstrated a higher number of labeled neurons; however, the differences were not significant. Histomorphometric indices were similar in the UCBMSCs and UCMSCs groups, and total axon counts, particularly axon density （P 〈 0.05）, were significantly greater in the UCBMSCs and UCMSCs groups than in the DMEM group. CONCLUSION： Transplanting either UCBMSCs or UCMSCs into axotomized sciatic nerves could accelerate and promote sciatic nerve regeneration over 8 weeks. Both treatments had similar effects on nerve regeneration.

Allogeneic Peripheral Blood Hematopoietic Stem Cell Transplantation for Patients with Hematologic Malignancies

To investigate the therapeutic effects and associated complications of allogeneic peripheral blood stem cell transplantation （allo-PBSCT）, 40 patients with various malignant hematopoietic diseases received allo-PBSCT. The preparative regimens were based on BUCY2 or modified BUCY2, The acute graft-versus host disease （aGVHD） was prevented by cyclosporin A and shortterm MTX regimen in all patients. Two patients from donors with one fully mismatched HLA on DRB1 locus and 4 from unrelated donor also administered Zenapox （CD25 MAb） at dosage of 1 rag/ kg every day on the day before transplantation and day 4 after transplantation. These 6 patients were also treated with mycophenolate mofetil （MMF）. Transfusion of the donor cells： The median of the transfused nucleated cells was 5.38×10^8/kg and that of the CD34^＋ cells was 7.8×10^6/kg respectively. All the patients gained hematopoietic reconstruction except one who died of infection before engraftment. Seven patients got Ⅱ°-Ⅳ° aGVHD and the incidence was 17.5 %. Fourteen patients got cGVHD and the incidence was 53.8 % in the patients who survived over 6 months. Twenty-eight patients had fever or other characteristics of infection. The median follow-up time was 13.8 months. The incidence of transplantation related mortality （TRM） was 17.5 %and 2 patients relapsed （5.0 %）. It was concluded that allo-PBSCT can reconstruct hematopoiesis quickly and is a favorable therapeutic method for leukemia.

Day 100 Absolute Monocyte/Lymphocyte Prognostic Score and Survival Post Autologous Peripheral Blood Hematopoietic Stem Cell Transplantation in Diffuse Large B-Cell Lymphoma

Day 100 prognostic factors post-autologous peripheral blood hematopoietic stem cell transplantation (APBHSCT) to predict clinical outcomes in diffuse large B-cell lymphoma (DLBCL) patients have not been studied. Thus, we retrospectively examined if day 100 absolute monocyte/lymphocyte prognostic score (AMLPS-100) affects clinical outcomes by landmark analysis from day 100 post-APBHSCT in DLBCL. Only DLBCL patients in complete remission at day 100 post-APBHSCT were evaluated. From 2000 to 2007, 134 consecutive DLBCL patients are qualified for the study. Patients with a day 100 absolute monocyte count (AMC-100) ≥ 630 cells/μL and day 100 absolute lymphocyte count (ALC-100) ≤ 1000 cells/μL experienced inferior overall survival (OS) and progression free survival (PFS). On multivariate analysis, the AMC-100 and ALC-100 remained independent predictors of OS and PFS. Combining both values into the AMLPS-100, the 5-year OS rates for low, intermediate, and high AMLPS-100 risk groups were 94% (95% CI, 83.0% - 98.1%), 70% (95% CI, 58.6% - 80.1%), and 13% (95% CI, 3.4% - 40.5%), respectively;and the 5-year PFS rates were 87% (95% CI, 74.0% - 94.1%), 68% (95% CI, 56.0% - 77.8%), and 13% (95% CI, 3.4% - 40.5%), respectively. The AMLPS-100 is a simple biomarker score that can stratify clinical outcomes from day 100 post-APBHSCT in DLBCL patients.

Role of adipose tissue grafting and adipose-derived stem cells in peripheral nerve surgery

The application of autologous fat grafting in reconstructive surgery is commonly used to improve functional form.This review aims to provide an overview of the scientific evidence on the biology of adipose tissue,the role of adipose-derived stem cells,and the indications of adipose tissue grafting in peripheral nerve surgery.Adipose tissue is easily accessible through the lower abdomen and inner thighs.Non-vascularized adipose tissue grafting does not support oxidative and ischemic stress,resulting in variable survival of adipocytes within the first 24 hours.Enrichment of adipose tissue with a stromal vascular fraction is purported to increase the number of adipose-derived stem cells and is postulated to augment the long-term stability of adipose tissue grafts.Basic science nerve research suggests an increase in nerve regeneration and nerve revascularization,and a decrease in nerve fibrosis after the addition of adipose-derived stem cells or adipose tissue.In clinical studies,the use of autologous lipofilling is mostly applied to secondary carpal tunnel release revisions with promising results.Since the use of adipose-derived stem cells in peripheral nerve reconstruction is relatively new,more studies are needed to explore safety and long-term effects on peripheral nerve regeneration.The Food and Drug Administration stipulates that adipose-derived stem cell transplantation should be minimally manipulated,enzyme-free,and used in the same surgical procedure,e.g.adipose tissue grafts that contain native adipose-derived stem cells or stromal vascular fraction.Future research may be shifted towards the use of tissue-engineered adipose tissue to create a supportive microenvironment for autologous graft survival.Shelf-ready alternatives could be enhanced with adipose-derived stem cells or growth factors and eliminate the need for adipose tissue harvest.

Efficacy of peripheral blood stem cell transplantation versus conventional chemotherapy on anaplastic large-cell lymphoma:a retrospective study of 64 patients from a single center

Anaplastic large-cell lymphoma(ALCL) is characterized by frequently presenting adverse factors at diagnosis.Many groups believed aggressive treatment strategies such as autologous stem cell transplantation brought survival benefit for ALCL patients.However,few compared these approaches with conventional chemotherapy to validate their superiority.Here,we report a study comparing the efficacy of peripheral blood stem cell transplantation(PBSCT) and conventional chemotherapy on ALCL.A total of 64 patients with primary systemic ALCL were studied retrospectively.The median follow-up period was 51 months(range,1-167 months).For 48 patients undergoing conventional chemotherapy only,the 4-year event-free survival(EFS) and overall survival(OS) rates were 70.7% and 88.3%,respectively.Altogether,16 patients underwent PBSCT,including 11 at first remission(CR1/PR1),3 at second remission,and 2 with disease progression during first-line chemotherapy.The 4-year EFS and OS rates for patients underwent PBSCT at first remission were 81.8% and 90.9%,respectively.Compared with conventional chemotherapy,PBSCT did not show superiority either in EFS(P = 0.240) or in OS(P = 0.580) when applied at first remission.Univariate analysis showed that patients with B symptoms(P = 0.001),stage III/IV disease(P = 0.008),bulky disease(P = 0.075),negative anaplastic lymphoma kinase(ALK) expression(P = 0.059),and age ≤ 60 years(P = 0.054) had lower EFS.Furthermore,PBSCT significantly improved EFS in patients with B symptoms(100% vs.50.8%,P = 0.027) or bulky disease(100% vs.52.8%,P = 0.045) when applied as an up-front strategy.Based on these results,we conclude that,for patients with specific adverse factors such as B symptoms and bulky disease,PBSCT was superior to conventional chemotherapy in terms of EFS.

CYTOMEGALOVIRUS INTERSTITIAL PNEUMONITIS FOLLOWING ALLOGENEIC PERIPHERAL BLOOD STEM CELL TRANSPLANTATION

Objective： To explore the risk factors and prophylaxis and treatment of cytomegalovirus interstitial pneumonitis （CMV-IP） after allogeneic peripheral blood stem cell transplantation （allo-PBSCT）. Methods： 43 patients who received allo-PBSCT were allocated to either a Gancyclovir（GCV）-prophylaxis group （n=19） or a non-GCV prophylaxis group （n=24）. A comparison was made of the incidence of CMV-IP in patients given or not given prophylactic gancyclovir. Results： 9 patients in non-GCV prophylaxis group developed late CMV-IP （P〈0.05）. Graft-versus-host-disease （GVHD） may be associated with a high risk of CMV-IP. 5 cases of CMV-IP were successfully treated with GCV, but 3 cases died of CMV-IP. The most common adverse event of GCV was neutropenia, but was reversible. Conclusion： CMV infection was a major cause of interstitial pneumonitis after allo-PBSCT, which correlated strongly with the severity of GVHD. Gancyclovir was shown to be effective in both prophylaxis and treatment of CMV-IP.

IN VITRO STUDY ON CRYOPRESERVATION OF PERIPHERAL BLOOD STEM CELLS WITH UNCONTROLLED FREEZER

Objective: To evaluate the effects of cryopreservation of APBSCs in ?80°C un-controlled freezer and liquid nitrogen, and to search for the efficient combined cryoprotectant and the highest cell concentration for cryopreservating peripheral blood stem cell (PBSC). Methods: To compare the effect of three combined cryoprotectants, evaluation of in vitro proliferative capacity by colony-forming unit-Granulocyte-macrophage (CFU-GM) and burst-forming Unit-erythroid (BFU-E) assay, immunophenotyping for CD34+/CD38? cells by FCM, and viability assessment by trypan blue exclusion were performed. Results: The cryoprotectant 10%DMSO+HES+auto-Plasma resulted in the highest recovery rates. CFU-GM and BFU-E were (78.7±9.8)%, (69.8±14.1)%, respectively. The recovery rates of CFU-GM and BFU-E in A/C groups were (68.3±6.2)%/ (65.8±7.2)% and (63.4±9.7)%/ (60.4±10.5)%, respectively. The recovery rates of CD34+/CD38? cells and cell viability with the three combined reagents were 90% and 80%, respectively. Conclusion: 5%DMSO+ HES+auto-PLASMA is an ideal combined cryoprotectant for cryopreserving PBSC. The cell concentrations may be cryopreserved at 4×108 ml?1.

HIGH-DOSE CHEMOTHERAPY WITH AUTOLOGOUS PERIPHERAL BLOOD STEM CELL SUPPORT IN CHILDREN WITH MALIGNANT DISEASES

Objective： To determine the potential effectiveness and toxicity of this therapy in children with advanced neuroblastoma or malignant lymphoma. Methods： Carboplatin （425 mg/m^2·d） and etoposide （338 regime-d） were given as a 24 h continuous IV infusion on days -7, -6, -5 and -4, and melphalam （70 mg/m^2·d） by bolus IV infusion at hour 0 of days -7, -6, and - 5（CEM）. Or busulphan was given as 1 mg/kg.6 h orally on days -6, -5, -4, and melphalam （140 mg/m^2） by IV bolus infusion on day-3（BM）. Treatment regimens followed by autologous PBSC infusion were performed in 19 children with neuroblastoma （n=12） or malignant lymphoma （n=7） for consolidation treatment. There were thirteen males and six females, with a median age of 6.4 years （raging 3.5-13 years）. Results： The median period of achieving ANC 〉0.5×10^9/L, WBC〉1.0×10^9/L, and platelet 〉20×10^9/L after infusion of PBSCs were 21 d, 17 d, and 33 d respectively. Stomatitis occurred in 16 children （86%）, and twelve had gastrointestinal toxicity （64%）. Complete remission （CR） was achieved in 14 （74%） children. Fifteen patients （79%） survived. Ten patients （53%） are alive in CR. These patients are alive for a median of 639 days and disease-free for 909 d after transplantation. Four cases （21%） relapsed, and four cases （21%） died. Conclusion： CEM or BM regimen followed by autologous PBSCT infusion is safe and feasible, and has significant effects in children with advanced neuroblastoma or malignant lymphoma.

Comparative characterization of human fetal neural stem cells and induced neural stem cells from peripheral blood mononuclear cells

Human-induced neural stem cells(iNSCs)transplantation is a potential treatment of neurodegeneration diseases.However,whether the reprogrammed cells have the same characterizations as human fetal neural stem cells needs further exploration.Here we isolated human fetal neural stem cells from aborted 12-week fetal brains and compared with iNSCs reprogrammed from human peripheral blood mononuclear cells in gene expression,proliferation ability,differentiation capacity,and the responses to tumor necrosis factor-α.We found that iNSCs and NSCs both expressed neural stem cell markers Nestin,SOX1,and SOX2.However,only iNSCs can be patterned into dopaminergic neurons and motor neurons.Furthermore,both iNSCs and NSCs can differentiate into oligodendrocyte progenitor cells.In addition,a low dose of tumor necrosis factor-αdid not inhibit the proliferation and differentiation of iNSCs and NSCs.In conclusion,iNSCs have properties similar to,and even better than,fetal neural stem cells and may be suitable for disease modeling and transplantation.

Hematopoietic stem cells from peripheral blood the perspective of non-mobilized peripheral blood

The peripheral blood is a major source of hematopoietic stem cells. Almost for two decades the peripheral blood has been mobilized, in order to enhance the CD34+ concentration. The isolated stem cells from the mobilized peripheral blood are used as an alternative, or in addition to bone marrow derived stem cells. In this paper, a new perspective is being discussed;the use of non-mobilized peripheral blood as an alternative source for hematopoietic progenitor cells. The number of isolated hematopoietic stem cells is evaluated using flow cytometry. The viability can be evaluated using the trypan blue exclusion test, the flow cytometry or automated assays. The isolated hematopoietic stem cells could be used for ex vivo expansion either in static systems or in proper bioreactor systems, prior to cryopreservation and/or transplantation.

Hypoxic pre-conditioned adipose-derived stem/progenitor cells embedded in fibrin conduits promote peripheral nerve regeneration in a sciatic nerve graft model

Recent results emphasize the supportive effects of adipose-derived multipotent stem/progenitor cells(ADSPCs)in peripheral nerve recovery.Cultivation under hypoxia is considered to enhance the release of the regenerative potential of ADSPCs.This study aimed to examine whether peripheral nerve regeneration in a rat model of autologous sciatic nerve graft benefits from an additional custom-made fibrin conduit seeded with hypoxic pre-conditioned(2%oxygen for 72 hours)autologous ADSPCs(n=9).This treatment mode was compared with three others:fibrin conduit seeded with ADSPCs cultivated under normoxic conditions(n=9);non-cell-carrying conduit(n=9);and nerve autograft only(n=9).A 16-week follow-up included functional testing(sciatic functional index and static sciatic index)as well as postmortem muscle mass analyses and morphometric nerve evaluations(histology,g-ratio,axon density,and diameter).At 8 weeks,the hypoxic pre-conditioned group achieved significantly higher sciatic functional index/static sciatic index scores than the other three groups,indicating faster functional regeneration.Furthermore,histologic evaluation showed significantly increased axon outgrowth/branching,axon density,remyelination,and a reduced relative connective tissue area.Hypoxic pre-conditioned ADSPCs seeded in fibrin conduits are a promising adjunct to current nerve autografts.Further studies are needed to understand the underlying cellular mechanism and to investigate a potential application in clinical practice.

Induced-pluripotent stem cells seeded acellular peripheral nerve graft as “autologous nerve graft”

The hypothesis is that induced pluripotent stem cells (iPSC) derived Schwann cells and/or macrophages can be transplanted into acellular nerve graft in repairing injured nervous system. The efficiency of iPSC seeded acellular nerve graft may mimic the autologous peripheral nerve graft.

The safety of autologous peripheral blood stem cell transplantation by intracoronory infusionin in patients with acute myocardial infarction

Objective Bone-marrow stem-cell transplantation has been shown to improve cardiac function in patients with AMI, but the safety of intracoronory infusion of autologous peripheral blood stem-cell(PBSCs) in patients with AMI is unknown. For this reason, we observe the feasibility and safety of PBSCs transplantation by intracoronory infusion in such patients.Method Fourty one patients with AMI were allocated to receive Granulocyte Colony-Stimulating Factor (G-CSF:Filgrastim,300 μg) with the dose of 300 μg-600 μg/day to mobilize the stem cell, and the duration of applying G-CSF was 5 days . On the sixth day, PBSCs were separated by Baxter CS 3000 blood cell separator into suspend liquid 57 ml. Then the suspend liquid was infused into the infarct related artery (IRA)by occluding the over the wire balloon and infusing artery through balloon center lumen. In the process of the intracoronary infusion of PBSCs, the complications should be observed, which were arrhythmias including of bradycardia, sinus arrest or atrial ventricular block, premature ventricular beats ,ventricular tachycardia, ventricular fibrillation; and hypotention, etc. Results There were total 10 cases with complications during the intracoronary infusion of PBSCs. The incidence of complications was 24.4%(10/41), including bradycardia is 2.4 %(1/41), sinus arrest or atrial ventricular block is 4.9%(2/41), ventricular fibrillation is 2.4 %( 1/41), hypotention is14.6 % (6 /41).Conclusions In patients with AMI, intracoronary infusion of PBSCs is feasible and safe.

Isolation and Characterization of Multipotent and Pluripotent Stem Cells from Human Peripheral Blood

Stem cells are commonly classified based on the developmental stage from which they are isolated, although this has been a source of debate amongst stem cell scientists. A common approach classifies stem cells into three different groupings: Embryonic Stem Cells (ESCs), Umbilical Cord Stem Cells (UCBSCs) and Adult Stem Cells (ASCs), which include stem cells from bone marrow (BM), fat tissue (FT), engineered induced pluripotent (IP) and peripheral blood (PB). By definition stem cells are progenitor cells capable of self-renewal and differentiation hypothetically “ab infinitum” into more specialized cells and tissue. The main intent of this study was to determine and characterize the different sub-groups of stem cells present within the human PB-SCs that may represent a valid opportunity in the field of clinical regenerative medicine. Stem cells in the isolated mononucleated cells were characterized using a multidisciplinary approach that was based on morphology, the expression of stem cell markers by flowcytometry and fluorescence analysis, RT-PCR and the capacity to self-renew or proliferate and differentiate into specialized cells. This approach was used to identify the expression of hematopoietic, mesenchymal, embryonic and neural stem cell markers. Both isolated adherent and suspension mononucleated cells were able to maintain their stem cell properties during in-vitro culture by holding their capacity for proliferation and differentiation into osteoblast cells, respectively, when exposed to the appropriate induction medium.