Autologous Stem Cell Research Articles

Flat-dose granulocyte colony-stimulating factor evaluation after autologous hematopoietic stem cell transplant in multiple myeloma patients: Does one dose fit all?

The current recommended granulocyte-colony stimulating factor (G-CSF) dose after autologous hematopoietic stem cell transplant (autoHSCT) in multiple myeloma patients is 5 mcg/kg/day administered subcutaneously until engraftment. Recently, our institution changed practice from weight-based to flat-dose G-CSF. The purpose of this study was to assess the impact of flat-dose G-CSF on time to engraftment among multiple myeloma patients of different weight groups. Retrospective chart review was completed for adult patients with multiple myeloma who underwent autoHSCT from March 2018 through August 2019. Data collected included time to neutrophil engraftment, total length of hospitalization, length of stay post-transplant, time to platelet engraftment, use of intravenous fluconazole or acyclovir, parenteral nutrition use, incidence of febrile neutropenia, antibiotic use, and death. Differences in outcomes were compared between patients ≤80 kg versus those >80 kg. A secondary analysis was completed for patients ≤100 kg versus those >100 kg. There was no difference in time to neutrophil engraftment between weight groups (≤80 kg versus >80 kg: median = 12 days, p = 0.22; ≤100 kg versus >100 kg: median = 12 days, p = 0.52). There was a significant difference in intravenous fluconazole and acyclovir use between groups, with more use in the lower weight groups (≤80 kg versus >80 kg: 12 patients versus 10 patients p = 0.02; ≤100 kg versus >100 kg: 19 patients versus 3 patients p = 0.04). No significant differences were found for any other outcomes. Utilizing a flat-dose of G-CSF for patients after autoHSCT does not appear to negatively affect patient outcomes. Institutions may benefit from using the 300 mcg dose of G-CSF for multiple myeloma patients after autoHSCT.

Autologous mesenchymal stem cells in treatment of liver cirrhosis: evaluation of effectiveness and visualization method

Through clinical observation, we present an assessment of the autologous mesenchymal stem cells effectiveness in treatment of liver cirrhosis of alimentary etiology. In order to determine the localization of the implanted cell structures, the stem cells were previously labeled with iron (II, III) oxide nanoparticles (IONPs). Further MRI visualization helped to detect the cell structures stained with iron oxide nanoparticles in the human body. In 6 months after the cell therapy, the patient underwent clinical and biochemical blood tests, MEGX test, elastography and subjective health assessment test. The tests data analysis revealed the improvement of the values of all examined parameters after the cell treatment. Also in 6 and 12 months after the treatment, a liver biopsy was performed from the area where the implanted stem cells were visualized. In histological examination of liver bioptates obtained from the area of MSC transplantation, the largest number of stained cells was observed in liver micronodes, as well as at the boundaries of micronodes and fibrous septa. A portion of the bioptate obtained in 12 months after transplantation was used to produce primary cell cultures. Before the first re-seeding of the cultures, cell colonies of both fibroblast-like morphology and epithelial were detected in them. Both types of colonies contained the particles.
 Conducting the cell therapy to a patient with liver cirrhosis of alimentary etiology contributed to improving the laboratory and instrumental examinations indicators. The patient had come through the treatment procedure satisfactorily, no complications were registered.

Autologous Bone Marrow Cell Therapy for the Knee: Are We There Yet?

Knee pathology including osteoarthritis and chondral defects continue to account for a large burden of health care visits and significant dysfunction among patients. Injectable biologics have become a focus of greater interest as treatment to mitigate symptoms and potentially restore function or structure. In particular, bone marrow derived treatments, such as aspirated bone marrow aspirate concentrate (commonly referred to as BMAC) have attracted attention as one of the few options that may contain viable autologous stem and progenitor cells that are compliant with Federal Drug Administration regulations. However, recent literature has reported significant shortcomings including variability in the preparation methods, quality reporting, and outcome measures used to assess BMAC efficacy. This manuscript provides a comprehensive review of the most recent recommendations for processing and reporting BMAC in clinical trials with special focus on knee pathology, and presents an evidence-based discussion of the most recent studies reporting on patient outcomes.

Autologous hematopoietic stem cell transplantation with inadequate stem cell dose in patients with non-Hodgkin lymphoma

Little is known regarding the outcome of lymphoma patients undergoing autologous hematopoietic stem cell transplantation (AHSCT) using inadequate hematopoietic stem cell (HSC) doses. Fifty-six patients were enrolled in the study, and the cohort was subdivided into two groups according to the infusion dose: < 1 × 106/kg (poor HSC group) and 1–2 × 106/kg (unfavorable HSC group). Compared with the unfavorable group, the poor HSC group had a longer median time to neutrophil (13 vs. 11 days, p = .007) and platelet engraftment (17 vs. 13 days, p = .024). CD34+ cell infusion dose of < 1 × 106/kg was the only risk factor for neutrophil and platelet engraftment. The expected 3-year progression-free survival and overall survival rates for the whole cohort were 53% and 66%, and no statistical difference was observed between two groups. In conclusion, inadequate HSC infusion dose did not negatively impact AHSCT patient survival but significantly prolonged the time to hematopoietic engraftment.

Treating relapsed and refractory metastatic germ cell tumours with high-dose chemotherapy with carboplatin and etoposide and autologous haematopoietic stem cell transplantation.

To demonstrate the real-life data about patients who underwent AHSCT due to GCT. Between November 2016 and April 2020, 64 patients who received CE as high-dose chemotherapy for AHSCT in the Gulhane Education and Research Hospital were included in the study. Sixty-one patients received one AHSCT with CE chemotherapy regimen. Survival data and clinical characteristics were evaluated retrospectively. The mean age of the patients were 31.9 ± 9 (min-max:18-55). With a median follow-up of 10.7 ± 8.7 months, the 1-year progression-free survival (PFS) rate was 57.8%, and the 1-year overall survival rate was 77.5%. Median overall survival (OS) and progression-free survival (PFS) times were 21.5 ± 1.8 (95% CI: 14.5-33.4) and 20 ± 2 months, respectively. The response rate was 72%. There were three treatment-related deaths. This sizeable single-centre study shows that patients with relapsed metastatic GCT are curable by CE as high dose chemotherapy plus AHSCT with reliable toxicity even for a single cycle.

T-cell lymphoma with a granulomatous lesion of the lungs after autologous hematopoietic stem cell transplantation for Epstein\u2013Barr virus-positive diffuse large B-cell lymphoma: a unique rare case of metachronous B-cell and T-cell lymphoma

BackgroundEpstein–Barr virus (EBV) is associated with the pathogenesis of a variety of malignancies, most notably lymphomas. Especially in the background of immunodeficiency, such as primary immunodeficiency disorder (PID) and post-transplant lymphoproliferative disorder (PTLD), the role of EBV might be crucial. PIDs are rare heterogeneous diseases affecting the development and/or the function of the innate and adaptive immune system. Malignancy is the second-highest cause of death after infection, and lymphoma accounts for about half of malignancies. The most frequently reported lymphoma type is diffuse large B-cell lymphoma (DLBCL) and the incidence of T-cell lymphoma is rare. PTLDs are also rare serious lymphoid and/or plasmacytic proliferative disorders that occur after undergoing solid organ or hematopoietic stem cell transplantation (HSCT). In the context of HSCT, most reported PTLDs have occurred in patients who received allogenic HSCT, but only a few cases have been reported in autologous HSCT (AutoHSCT) recipients.Case presentationA 53-year-old female patient initially presented with enlargement of the left cervical lymph nodes and was diagnosed with EBV-positive DLBCL. She was treated with R-CHOP, R-ACES, and AutoHSCT and went into remission. Four years later, computed tomography results revealed multiple lung nodules and abnormal infiltration, and sustained and progressing hypogammaglobulinemia was observed. The pathological specimen of video-assisted thoracoscopic surgical lung biopsy demonstrated extensive invasion of lymphocytes with notable granuloma findings. Flow cytometric immunophenotyping analysis showed that lymphocytes were positive for CD3 and CD5; especially, CD3 was expressed in the cytoplasm. Southern blot analysis revealed rearrangements of the T-cell receptor Cβ1 gene. She was diagnosed with peripheral T-cell lymphoma, not otherwise specified, accompanied by notable granulomatous lesions.ConclusionHere, as a unique case of metachronous B-cell and T-cell lymphoma, we report a rare case of T-cell lymphoma that mainly affected the lungs with the presentation of notable granulomatous findings following AutoHSCT for EBV-positive DLBCL at the age of 53 years. These lung lesions of granulomatous T-cell lymphoma could be related to the underlying primary immunodeficiency background associated with sustained hypogammaglobulinemia.

Anti-GD2 immunotherapy with the chimeric antibody ch14.18 for high-risk neuroblastoma

Neuroblastoma is the most common extracranial solid tumor in children 0–14 years old. Current risk-adapted treatment programs are based on stratification of patient into three risk groups. 40–50% of patients are stratified into the high-risk group. The prognosis in high-risk patients remains poor (the probability of long-term survival is less than 50%), despite the use of aggressive multimodal therapy, including high-dose chemotherapy and autologous hematopoietic stem cell transplantation. In most cases tumor cells in neuroblastoma express disialoganglioside GD2, which is a possible target for immunotherapy. Over the past 30 years, GD2-directed chimeric monoclonal antibodies ch14.18 have been introduced into clinical practice. A number of clinical studies have shown an improvement in the prognosis in patients with high-risk neuroblastoma, when using monoclonal antibodies ch14.18, primarily due to the eradication of the minimal residual population of tumor cells resistant to standard chemotherapy. This literature review summarizes the international experience in the use of monoclonal antibodies ch14.18 from early phases of clinical trials to large randomized trials, which allowed immunotherapy to be considered as an important component of multimodal therapy for high-risk neuroblastoma. Future prospects for the use and place of immunotherapy in first-line therapy of high-risk neuroblastoma and in relapsed setting are considered.

Outcome of high-dose chemotherapy with autologous haematopoietic stem cell rescue in childhood central nervous system tumours: Experience from University of Malaya medical centre, Kuala Lumpur

Outcome of high-dose chemotherapy with autologous haematopoietic stem cell rescue in childhood central nervous system tumours: Experience from University of Malaya medical centre, Kuala Lumpur

High dose chemotherapy with autologous hematopoietic stem cell rescue for patients with high risk medulloblastoma- A single centre experience in South India

High dose chemotherapy with autologous hematopoietic stem cell rescue for patients with high risk medulloblastoma- A single centre experience in South India

Therapeutic angiogenesis using autologous adipose-derived regenerative cells in patients with critical limb ischaemia in Japan: a clinical pilot study

Adipose-derived regenerative cell (ADRC) is a promising alternative source of autologous somatic stem cells for the repair of damaged tissue. This study aimed to assess the safety and feasibility of autologous ADRC implantation for therapeutic angiogenesis in patients with critical limb ischaemia (CLI). A clinical pilot study—Therapeutic Angiogenesis by Cell Transplantation using ADRCs (TACT-ADRC) study—was initiated in Japan. Adipose tissue was obtained by ordinary liposuction method. Isolated ADRCs were injected into the ischaemic limb. We performed TACT-ADRC procedure in five patients with CLI. At 6 months, no adverse events related to the TACT-ADRC were observed. No patients required major limb amputation, and ischaemic ulcers were partly or completely healed during the 6-month follow-up. In all cases, significant clinical improvements were seen in terms of rest pain and 6-min walking distance. Numbers of circulating CD34+ and CD133+ cells markers of progenitor cell persistently increased after ADRC implantation. The ratio of VEGF-A165b (an anti-angiogenic isoform of VEGF) to total VEGF-A in plasma significantly decreased after ADRC implantation. In vitro experiments, cultured with ADRC-conditioned media (CM) resulted in increased total VEGF-A and decreased VEGF-A165b in C2C12 cells, but not in macrophages. ADRC-CM also increased CD206+ cells expression and decreased TNF-α in macrophages. Autologous ADRC implantation was safe and effective in patients with CLI and could repair damaged tissue via its ability to promote angiogenesis and suppress tissue inflammation.

Autologous Stem Cells in Cervical Spine Fusion.

Study Design:Systematic review.Objectives:To systematically review, critically appraise and synthesize evidence on use of stem cells from autologous stem cells from bone marrow aspirate, adipose, or any other autologous sources for fusion in the cervical spine compared with other graft materials.Methods:A systematic search of PubMed/MEDLINE was conducted for literature published through October 31, 2018 and through February 20, 2020 for EMBASE and ClinicalTrials.gov comparing autologous cell sources for cervical spine fusion to other graft options.Results:From 36 potentially relevant citations identified, 10 studies on cervical fusion met the inclusion criteria set a priori. Two retrospective cohort studies, one comparing cancellous bone marrow (CBM) versus hydroxyapatite (HA) and the other bone marrow aspirate (BMA) combined with autograft and HA versus autograft and HA alone, were identified. No statistical differences were seen between groups in either study for improvement in function, symptoms, or fusion; however, in the study evaluating BMA, the authors reported a statistically greater fusion rate and probability of fusion over time in the BMA versus the non-BMA group. Across case series evaluating BMA, authors reported improved function and pain and fusion ranged from 84% to 100% across the studies. In general, complications were poorly reported.Conclusions:The overall quality (strength) of evidence of effectiveness and safety of autologous BMA for cervical arthrodesis in the current available literature was very low. Based on currently available data, firm conclusions regarding the effectiveness or safety of BMA in cervical fusions cannot be made.

Determination of the Involvement of Autologous Mesenchymal Bone Marrow Stem Cells in Reparative Chondrogenesis

Summary. Articular cartilage injuries are observed in 60% of arthroscopies. Degenerative changes of the articular cartilage (osteoarthritis) is the most common disease of all the joints, which affects at least 10-13% of the population over the age of 60 years. Significant progress has been made in the treatment of pain and inflammation, but the evidence base for improving the articular cartilage repair remains weak. Despite the seemingly positive results of a number of studies on the use of mesenchymal stem cells (MSCs) for the articular cartilage restoration, the question of the nature of their participation in this process remains controversial. Objective. The objective of the study was to determine the involvement of autologous mesenchymal bone marrow stem cells in reparative chondrogenesis. Materials and Methods. Experimental and morphological determination of the participation of undifferentiated autologous bone marrow MSCs in reparative chondrogenesis was carried out on fifteen rabbits. MSCs of bone marrow marked with a red fluorescent dye PKH-26 (Sigma, USA) was injected into the cavity of the injured joint on the 3rd day after the articular cartilage defect formation. The presence of the transplanted labeled autologous MSCs was examined in these animals on cryostat sections on the seventh, fourteenth and twenty-first days after implantation with fluorescence microscopy. The characteristic red glow was observed in case of the presence of labeled cells in the regenerated cartilage tissue. Results. The presence of transplanted labeled autologous MSCs on cryostat sections was determined in all studied animals. On the 7th day, the cells were arranged diffusely, without noticeable accumulations. On the 14th day, the labeled cells fluoresced in the red zone of the spectrum and created compact conglomerates mainly at the defect zone. On the 21th day, the labeled cells were found only in the regenerate zone. The data obtained indicate the direct participation of autologous MSCs in the processes of chondroreparation after the exogenous implantation into the joint cavity. Conclusions. The method of autologous bone marrow MSCs labeling using PKH-26 fluorescent dyes has shown that autologous bone marrow MSCs are directly involved in the processes of chondroreparation when they are injected intraarticularly.

Clinical and biological characteristics of neuroblastoma in adolescents and young adults. Case study and literature review

Introduction. Neuroblastoma (NB) is the most common extracranial solid tumor in infants, but it is more rarely found in older children. Only 1–2 % of cases are registered in adolescents and young adults. The long-term prognosis in these patients is highly unfavorable due to indolent clinical course formed by peculiar biological characteristics of tumors. We publish a case study of 11 patients with NB older than 10 years at the time of diagnosis.Case series description. In 2008 to 2020 a total of 11 adolescent and young adults patients with median age of 14 (10–28) years were treated in Raisa Gorbacheva Memorial Research Institute of Children Oncology, Hematology and Transplantation, First Pavlov State Medical University of St. Petersburg. Seven of 11 patients had mediastinal neuroblastoma, in other cases the primary lesion was abdominal (n = 2), pelvic (n = 1), and in one case no primary lesion was defined. Ten of 11 patients had primary disseminated disease with lymph nodes (n = 5), bone (n = 5), bone marrow (n = 3), or hepatic (n = 1) metastases. Tumor morphology and cytogenetics were assessed in all patients, in 4 cases additional targeted sequencing of potentially pathogenic genes was performed. All patients received chemotherapy and local control measures according to high-risk NB guidelines, in 7 of 11 cases additional chemotherapy regimens were used. Seven of 11 patients also received dose-intensive consolidation with autologous hemopoietic stem cell transplantation (auto-HSCT). In case of primary resistance MIBG-therapy, targeted or immunotherapy were used. In 6 cases tumor morphology corresponded to undifferentiated neuroblastoma, in 5 cases to ganglioneuroblastoma. Although all cases were high-risk, they mostly lacked high-risk biological features seen in younger patients. None had MYCN amplification, the cytogenetic assay yielded the following aberrations: +2 (n = 2), del1p (n = 1), g17q (n = 1). All patients, in whom the targeted sequencing was performed had pathogenic mutations: ATRX (in two patients 19 and 28 years at diagnosis), TP53 and PIK3CA, FBXW7. Nine of 11 patients had primary resistant disease, in 7 cases response was obtained on second or subsequent therapy lines. Two patients responded two chemoand targeted therapy combination, in 3 cases monoor combined immunotherapy yielded prolonged (16–32 months) response. Six of 7 auto-HSCT recipients developed a relapse. 6 out of 11 patients are currently alive. In 2 cases, a complete response is maintained according to scintigraphy with 123I-MIBG, lasting 86 and 14 months after completion of therapy.Conclusions. NB is biologically different in adolescents and young adults. It is characterized by indolent clinical course with very high risk of late relapse. As most patients in this group are chemoresistant, the standard dose-intensive tactics may be less effective and perhaps more attention should be given to targeted and immunotherapy-based approaches.

The use of autologous mesenchymal stem cells to improve the functional state of the liver after its resection (clinical observation)

The article provides a clinical observation with an assessment of biochemical indicators and changes in liver volume in the patient after liver resection. A peculiarity of this clinical observation is that intraoperative (during liver resection) administration of autologous mesenchymal stem cells was performed on this patient. In the postoperative period, the patient was not given protein and hepatotropic preparations. As a result of the use of cellular technologies, on the 15th day after the operation, the patient recovered protein function of the liver; 10 days after the operation, the level of prothrombin time and transaminases normalized; on day 5 after the operation, alkaline phosphatase and GGTP were normalized. Previously, we proved that autologous mesenchymal stem cells introduced through the portal vein of the liver are fixed directly in the liver tissue. These results were confirmed by magnetic resonance imaging. The introduced cell structures were visualized by pre-labeling them with iron oxide nanoparticles. The search for new ways to restore liver function after resections is a significant task in liver surgery, which in the future will help to improve the postoperative results of treatment of patients and reduce the bed-day.

Adipose‐derived autologous mesenchymal stem cell transfusion for the treatment of feline chronic gingivostomatitis in a domestic shorthair cat

This report describes a successful outcome following the use of adipose-derived autologous mesenchymal stem cell therapy for the treatment of refractory feline chronic gingivostomatitis in a domestic shorthair cat.

MM-069: Autologous Hematopoietic Stem Cell Transplant in Multiple Myeloma: Plerixafor Mobilization and Progression-Free Survival

Context: Plerixafor is a CXCR4 receptor antagonist developed for improving the mobilization of CD34+ cells prior to collection for autologous hematopoietic stem cell transplantation (Auto-HSCT) in hematologic malignancies, used when a high rate of insufficient collection by apheresis is expected. In multiple myeloma (MM), apart from an increase in the number of CD34+ cells, it has been shown a rise in the amount of plasma cells collected. Objective: Our hypothesis is that Plerixafor-mobilized patients and their potentially contaminated product could have an impact on their relapse-free survival. The primary outcome of this study was to evaluate if the addition of Plerixafor to filgrastim (G-CSF+P) for mobilization phase was related to a lower progression-free survival (PFS) compared to patients who received only filgrastim (G-CSF). Design: Observational, retrospective, longitudinal trial that included adults with MM who received Auto-HSCT between January 2012 to May 2019. Mean follow-up for surviving patients was 37 months. Setting: Hospital care, high-complexity center. Patients or other participants: 88 MM patients received Auto-HSCT in the studied period. 28 were excluded due to insufficient follow-up, second transplant, or missing relevant data. Median age was 57 years (range 31-73). A mean of 4.67 (± 2.42) and 6.65 (± 3.17) × 106 CD34+ cells/kg were infused in the G-CSF and G-CSF+P groups, respectively. Interventions: Follow-up after Auto-HSCT. Main outcome measures: Kaplan-Meier analysis to determine PFS and overall survival (OS). Results: Median PFS (n=60) was 24 months. In the subgroup analysis, PFS was 36.3 months for the filgrastim group (n=25) and 21.5 months for patients who received G-CSF+P (n=35; p=0.24). Median OS was 70 months (70 months vs not reached for G-CSF and G-CSF+P groups, respectively, p=0.6). Conclusions: Adding Plerixafor prior to autologous collection in MM showed a tendency towards a lower PFS, and a controlled trial with a larger sample size and longer follow-up is needed to define if this trend becomes statistically significant. Biological studies, such as the quantification of plasma cells and their apoptotic rate could add to the evaluation of the impact of the mobilized product in the relapse rate of MM patients.

Real-world efficacy of brentuximab vedotin plus bendamustine as a bridge to autologous hematopoietic stem cell transplantation in primary refractory or relapsed classical Hodgkin lymphoma

Up to 30% of patients with classical Hodgkin lymphoma (cHL) are not responsive to frontline therapy or relapse after primary treatment. In these cases, autologous hematopoietic stem cell transplantation (AHSCT) is the standard of care. The combination of brentuximab vedotin and bendamustine (BV + B) is an effective salvage regimen in this challenging subpopulation. This nationwide multicenter study investigated the real-world efficacy and safety of the BV + B regimen as a bridge to AHSCT in patients with primary refractory or relapsed cHL. A total of 41 cHL patients underwent AHSCT after receiving at least 1 cycle of BV + B (with brentuximab vedotin given at 1.8 mg/kg on day 1 and bendamustine at 90 mg/m2 on days 1–2 every 4 weeks). After a median of 3 (1–6) cycles of BV + B, the objective response rate was 78%, with 29 (70.7%) patients achieving complete remission. Twelve (29.3%) patients relapsed after AHSCT, 2 (4.9%) of them died, while 2 (4.9%) patients are lost to follow-up. After a median of 17 months of follow-up, the estimated 2-year overall- and progression-free survival after AHSCT was 93 and 62%, respectively. Features of advanced disease at recurrence (p = 0.038) and the presence of stage IV cHL at relapse (p = 0.024) are strong predictor markers of unfavorable outcomes. Twenty-four (58.5%) patients experienced adverse events of any grade, while no grade IV toxicities were reported. BV + B is an effective salvage option with a manageable toxicity profile in cHL. The real-world safety and efficacy of this combination are similar to the observations made on the study population.

Microencapsulated islet allografts in diabetic NOD mice and nonhuman primates.

Our goal was to assess the efficacy of encapsulated allogeneic islets transplanted in diabetic NOD mice and streptozotocin (STZ)-diabetic nonhuman primates (NHPs). Murine or NHP islets were microencapsulated and transplanted in non-immunosuppressed mice or NHPs given clinically-acceptable immunosuppressive regimens, respectively. Two NHPs were treated with autologous mesenchymal stem cells (MSCs) and peri-transplant oxygen therapy. Different transplant sites (intraperitoneal [i.p.], omental pouch, omental surface, and bursa omentalis) were tested in separate NHPs. Graft function was monitored by exogenous insulin requirements, fasting blood glucose levels, glucose tolerance tests, percent hemoglobin A1c (% HbA1c), and C-peptide levels. In vitro assessment of grafts included histology, immunohistochemistry, and viability staining; host immune responses were characterized by flow cytometry and cytokine/chemokine multiplex ELISAS. Microencapsulated islet allografts functioned long-term i.p. in diabetic NOD mice without immunosuppression, but for a relatively short time in immunosuppressed NHPs. In the NHPs, encapsulated allo-islets initially reduced hyperglycemia, decreased exogenous insulin requirements, elevated C-peptide levels, and lowered % HbA1c in plasma, but graft function diminished with time, regardless of transplant site. At necropsy, microcapsules were intact and non-fibrotic, but many islets exhibited volume loss, central necrosis and endogenous markers of hypoxia. Animals receiving supplemental oxygen and autologous MSCs showed improved graft function for a longer post-transplant period. In diabetic NHPs and mice, cell-free microcapsules did not elicit a fibrotic response. The evidence suggested that hypoxia was a major factor for damage to encapsulated islets in vivo. To achieve long-term function, new approaches must be developed to increase the oxygen supply to microencapsulated islets and/or identify donor insulin-secreting cells which can tolerate hypoxia.

Abstract 515: Non-invasive Method of Generating Human Induced-mesenchymal Stem Cells Derived From Urinary Epithelial Cells for Regenerative Therapy

Introduction: Mesenchymal stem cells (MSCs) are multipotent adult stem cells having an extensive proliferation capacity in vitro and in vivo. These MSCs can differentiate into various mesoderm-type cells such as osteoblasts, cardiomyocytes, etc. A subpopulation of urinary epithelial cells (UECs) have been identified in urine samples, is considered a promising cell resource for generating autologous induced-pluripotent stem cells (iPSCs). Hypothesis: We hypothesize that the production of high quality, autologous, induced-MSCs (iMSCs) with high replicative potential suitable for the regenerative therapy, using an easy, and the most non-invasive method of isolation, from human UECs. Methods and Results: Human urine was collected and centrifuged to obtain the UECs, which were characterized by the expression of CK19 and ZO1. These UECs were reprogrammed to iPSCs using a cocktail of mRNAs (OCT4, KLF4, SOX2, c-MYC, Nanog and Lin28) along with Lipofectamine for 11 days in culture. These iPSCs were characterized by the expression of the pluripotent markers such as OCT4, SOX2 and SSEA4. The iPSCs were subsequently differentiated into iMSCs using the mesenchymal specific medium for 21 days. iMSCs were harvested at the end of 21 days, and they were characterized by the high levels of mRNA and protein expressions of mesenchymal specific markers such as CD73, CD90 and CD105 (Fig. 1A). FACS analysis showed that more than 93% of the cells were positive for the markers of MSCs (Fig. 1B) . Moreover, the obtained iMSCs have high proliferation capacity compared with the adult stem cells. Conclusions: We have developed an easy, non-invasive method for obtaining autologous, non-immunogenic and highly-proliferating iMSCs suitable for various regenerative therapies including cardiac diseases, from urinary epithelial cells.

Abstract 226: Recellularization of Xenograft Heart Valves Reduces the Xenoreactive Immune Response in an In Vivo Rat Model

Background: Current xenograft valve constructs provoke an intense immune response that may lead to valve dysfunction. Our aim was to address the role of autologous mesenchymal stem cell (MSC) recellularization of xenogenic valves on the activation of the xenoreactive immune response in an in-vivo rat model. Methods: Explanted aortic valve constructs from female Hartley guinea pigs were procured and decellularized, followed by recellularization with syngeneic Sprague-Dawley rat MSCs. The recellularized aortic valve xenografts were then implanted into the infrarenal aorta of recipient female Sprague-Dawley rats. Grafts were implanted as either syngeneic grafts, non-decellularized (fresh), decellularized and recellularized xenografts. Rats were euthanized after 7-days, exsanguinated and the grafts explanted. Total serum immunoglobulin was quantified and histological analysis perfomed to analyze the immune response. Results: Overall survival to endpoint was significantly lower in the decellularized xenograft group (67%; 4/6), compared to fresh (100%; 6/6) and recellularized grafts (100%; 6/6). Similarly grafts in the decellularized group were more likely to have completely thrombosed (50%; 2/4), compared to fresh (33%; 2/6) and recellularized grafts (0%; 0/6). Decellularized guinea pig xenografts, when implanted into rats in-vivo , result in significantly reduced total serum immunoglobulin production and significantly reduced graft cellular infiltrate when compared to fresh xenografts. Moreover, when decellularized guinea pig xenografts were recellularized with syngeneic rat MSCs there was an additional decrease in total serum immunoglobulin production and graft cellular infiltrate when compared to both fresh and decellularized xenografts. Importantly, recellularized guinea pig xenografts had an equivalent total immunoglobulin production and graft cellular infiltrate when compared to syngeneic rat aortic valve controls. Conclusions: Autologous MSC recellularization of xenogenic valves reduces the xenoreactive immune response in an in-vivo rat model and may be an effective approach to decrease the progression of xenograft valve dysfunction.