Quality controls on cord blood unit contiguous segments: recommendation of the SFGM-TC.

In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapies (SFGM-TC) set up its fourth annual series of workshops which brought together practitioners from all of its member centers. These workshops took place in September 2013 in Lille. Literature and intra-laboratories studies suggest that attached segment is representative of cord blood unit (CBU). Nevertheless, some discrepancies have been observed when analyzing large data registries. To address these issues, we have listed recommendations to increase the standardization of segment processing and quality control (QC), information on units of measurement and specifications and action to be taken in case of out of specifications QC results on segment.

Outcomes, infections, and immune reconstitution after double cord blood transplantation in patients with high-risk hematological diseases.

Double unrelated cord blood transplant (dUCBT) has been used to circumvent cell dose limitation of single UCBT; however, few data are available describing outcomes, infectious disease, and immune recovery. We analyzed 35 consecutive dUCBT recipients with high-risk malignant disorders (n=21) and bone marrow failure syndromes (n=14). Median follow-up was 32 months. Conditioning regimen was myeloablative in 14 and reduced intensity in 21 patients. Median infused nucleated cell dose was 4 × 10(7) /kg. Median time to absolute neutrophil count >0.5 × 10(9) /L was 25 days. Cumulative incidence (CI) of acute grade II-IV graft-versus-host disease was 47%. Estimated overall survival at 2 years was 48%. CI of first viral infections at 1 year was 92%. We observed 49 viral infections in 30 patients, 34 bacterial infections in 19 patients, and 16 fungal or parasitic infections in 12 patients. Lymphocyte subset analyses were performed at 3, 6, 9, and >12 months after dUCBT. Decreased T-cell and B-cell counts with expansion of natural killer cells were observed until 9 months post transplantation. Recovery of thymopoiesis measured by T-cell receptor excision circles was impaired until 9 months after dUCBT, when the appearance of new thymic precursors was observed. Delayed immune recovery and high incidence of infectious complications were observed after dUCBT in patients with high-risk hematological diseases.

Cell therapy for prenatal repair of myelomeningocele: A systematic review.

Myelomeningocele (MMC) is a spinal cord congenital defect that leads to paraplegia, bladder incontinence and bowel dysfunction. A randomized human trial demonstrated that in utero surgical repair of the MMC defect improves lower limb motor function. However, functional recovery remains incomplete. Stem cell therapy has recently generated great interest in the field of prenatal repair of MMC. In this systematic review we attempt to provide an overview of the current application of stem cells in different animal models of MMC. Publications were retrieved from PubMed and Cochrane Library databases. This process yielded twenty-two studies for inclusion in this review, experimenting five different types of stem cells: human embryonic stem cells, neural stem cells, induced pluripotent stem cells, human amniotic fluid stem cells, and mesenchymal stem cells (MSCs). Rodents and ovine were the two major species used for animal model studies. The source, the aims, and the main results were analyzed. Stem cell therapy appears to be a promising candidate for prenatal repair of MMC, especially MSCs. Further explorations in ovine and rodent models, reporting clinical and functional results, are necessary before an application in humans.

Mesenchymal stem cells: Stem cell therapy perspectives for type 1 diabetes.

Mesenchymal stem cells (MSCs) are multipotent non-haematopoietic progenitor cells that are being explored as a promising new treatment for tissue regeneration. Although their immunomodulatory properties are not yet completely understood, their low immunogenic potential together with their effects on immune response make them a promising therapeutic tool for severe refractory autoimmune diseases. Type 1 diabetes is characterized by T cell-mediated autoimmune destruction of pancreatic beta cells. While insulin replacement represents the current therapy for type 1 diabetes, its metabolic control remains difficult, as exogenous insulin cannot exactly mimic the physiology of insulin secretion. Pancreatic or islet transplantation can provide exogenous insulin independence, but is limited by its intrinsic complications and the scarcity of organ donors. In this context, stem cell therapy, based on the generation of insulin-producing cells (IPCs) derived from MSCs, represents an attractive possibility. In this review, we provide a brief characterization of MSC immunomodulatory effects, and present the current experimental evidence for the potential therapeutic efficacy of MSC transplantation in diabetes.

[Mesenchymal stem cells and immunomodulation: toward new immunosuppressive strategies for the treatment of autoimmune diseases?]. / Cellules souches mésenchymateuses et immunomodulation : vers de nouvelles stratégies immunosuppressives pour le traitement des maladies auto-immunes ?

Mesenchymal stem cells (MSC) represent a population of the bone marrow microenvironment, which participates in the regulation of haematopoietic stem cells (HSC) self-renewal and differentiation. MSC are multipotent non-haematopoietic progenitors, which have been explored as a promising treatment in tissue regeneration. Both in vitro and in vivo, the MSC inhibit the T, B, NK and dendritic cell functions. Although MSC immunomodulating properties are not yet completely understood, their low immunogenic potential can be used as a therapeutic tool not only for regenerative medicine, but also for the treatment of graft-versus-host disease (GVHD) after bone marrow transplantation as well as for specific cases of severe refractory autoimmune diseases. Experimental and clinical data gave encouraging results, showing that MSC injection allowed controlling refractory GVHD, restoring bone development in children with osteogenesis imperfecta or improving heart function after myocardial infarction. Phase I-II studies are in progress in various countries to investigate the potential benefit from MSC due to their immunosuppressive properties, as an adjunctive therapy for severe refractory autoimmune disease.

Double cord blood transplantation in patients with high risk bone marrow failure syndromes.

Patients with bone marrow failure syndromes (BMFS) who reject a first allogeneic transplant or fail immunosuppressive therapy (IST) have an especially grim prognosis. We report 14 patients (eight adults, six children) transplanted with double cord blood transplantation (dUCBT) for BMFS. Neutrophil recovery was observed in eight patients, with full donor chimerism of one unit, and acute GVHD in 10. With a median follow-up of 23 months, the estimated 2 years overall survival was 80 +/- 17% and 33 +/- 16% for patients with acquired and inherited BMFS, respectively. Transplantation of two partially HLA-matched UCB thus enables salvage treatment of high-risk patients with BMFS.

Phenotypical and functional characteristics of in vitro expanded bone marrow mesenchymal stem cells from patients with systemic sclerosis.

BACKGROUND: Mesenchymal stem cells (MSCs) have a potential immunomodulatory role in autoimmune disease; however, the qualitative properties and haematopoietic support capacity of MSCs derived from patients with autoimmune disease is unclear. OBJECTIVES: To further characterise phenotypically and functionally bone marrow (BM)-derived MSCs from patients with systemic sclerosis (SSc). METHODS: Key parameters of BM-derived MSC function and phenotype were assessed in 12 patients with SSc and compared with 13 healthy normal controls. The parameters included the ability to: form colony-forming unit fibroblasts (CFU-F), differentiate along the adipogenic and osteogenic lineages, express cell surface antigens defining the MSCs population, support normal haematopoiesis and suppress in vitro lymphocyte proliferation induced by either anti-CD3epsilon plus anti-CD28 monoclonal antibodies or the mixed lymphocyte reaction. RESULTS: SSc MSCs were shown to have a similar characteristic phenotype, capacities to form CFU-F and to differentiate along adipogenic and osteogenic lineages as those of healthy donor MSCs. The ability of SSc MSCs to support long-term haematopoiesis was also identical to that of controls. Both healthy donor and SSc BM MSCs reduced the proliferation of autologous and allogeneic peripheral blood mononuclear cells in a cell number dependent fashion. CONCLUSIONS: These results show that BM-derived MSCs from patients with SSc under the described culture conditions exhibit the same phenotypic, proliferative, differentiation potential and immunosuppressive properties as their healthy counterparts and could therefore be considered in an autologous setting. Further studies are needed to ensure the quality and safety of large-scale expansion of patient MSCs prior to their potential use in clinical trials.

Long-term follow-up results after autologous haematopoietic stem cell transplantation for severe systemic sclerosis.

OBJECTIVE: Systemic sclerosis (SSc) is a generalised autoimmune disease, causing morbidity and a reduced life expectancy, especially in patients with rapidly progressive diffuse cutaneous SSc. As no proven treatment exists, autologous haematopoietic stem cell transplantation (HSCT) is employed as a new therapeutic strategy in patients with a poor prognosis. This study reports the effects on survival, skin and major organ function of HSCT in patients with severe diffuse cutaneous SSc. PATIENTS AND METHODS: A total of 26 patients were evaluated. Peripheral blood stem cells were collected using cyclophosphamide (4 g/m2) and rHu G-CSF (5 to 10 microg/kg/day) and were reinfused after positive CD34+ selection. For conditioning, cyclophosphamide 200 mg/kg was used. RESULTS: After a median follow-up of 5.3 (1-7.5) years, 81% (n = 21/26) of the patients demonstrated a clinically beneficial response. The Kaplan-Meier estimated survival at 5 years was 96.2% (95% CI 89-100%) and at 7 years 84.8% (95% CI 70.2-100%) and event-free survival, defined as survival without mortality, relapse or progression of SSc, resulting in major organ dysfunction was 64.3% (95% CI 47.9-86%) at 5 years and 57.1% (95% CI 39.3-83%) at 7 years. CONCLUSION: This study confirms that autologous HSCT in selected patients with severe diffuse cutaneous SSc results in sustained improvement of skin thickening and stabilisation of organ function up to 7 years after transplantation.

Phenotypic and functional characterization of bone marrow mesenchymal stem cells derived from patients with multiple myeloma.

Multiple myeloma (MM) is a B-cell neoplasia caused by the proliferation of clonal plasma cells, primarily in the bone marrow (BM). The role of the BM microenvironment in the pathogenesis of the disease has been demonstrated, especially for the survival and growth of the myeloma plasma cells. Functional characterization of the major component of the BM microenvironment, namely the recently characterized mesenchymal stem cells (MSCs), was never performed in MM. Based on a series of 61 consecutive patients, we evaluated the ability of MSCs derived from myeloma patients to differentiate into adipocytes and osteocytes, inhibit T-cell functions, and support normal hematopoiesis. MSCs phenotypic characterization and quantification of interleukin-6 (IL-6) secretion were also performed. As compared to normal MSCs, MSCs from MM patients exhibited normal phenotype, differentiation capacity and long-term hematopoietic support, but showed reduced efficiency to inhibit T-cell proliferation and produced abnormally high amounts of IL-6. Importantly, these characteristics were observed in the absence of any detectable tumor plasma cell. Chromosomal analysis revealed that MM patients MSCs were devoid of chromosomal clonal markers identified in plasma cells. MM MSCs present abnormal features that may participate in the pathogenesis of MM.

Recovery, viability and clinical toxicity of thawed and washed haematopoietic progenitor cells: analysis of 952 autologous peripheral blood stem cell transplantations.

Cryopreservation and thawing of haematopoietic stem cells are associated with cell loss and infusion-related toxicities. We analysed viability, total nucleated cell (TNC) and CD34+ cell recovery, and infusion-related toxicities of 952 thawed and washed products. Mean TNC and CD34+ viable cells recoveries were 55.9+/-18.6 and 98.0+/-36.5%, respectively. Mean cell viability was 68.25+/-18.9%. TNC recovery was correlated with viability but independent of the initial nucleated cell concentration. No difference in TNC recovery or viability was observed according to underlying diseases, except for myeloma, for which these variables were significantly lower (P<0.05). CD34+ cell recovery was not correlated with viability or CD34+ initial count and was similar for all diseases. Cryostorage duration was not associated with cell loss. Immediate adverse events occurred in 169 patients (19%) and were moderate (grade I or II) for the majority of patients. Clinical toxicity was associated with a higher infused cell number and the presence of clumps in infused bags. The washing procedure of cell products lead to a low rate of adverse events, but patients transplanted with high cell numbers or bags in which clumps were identified are predisposed to such complications.

Pro-angiogenic effect of RANTES-loaded polysaccharide-based microparticles for a mouse ischemia therapy.

Peripheral arterial disease results from the chronic obstruction of arteries leading to critical hindlimb ischemia. The aim was to develop a new therapeutic strategy of revascularization by using biodegradable and biocompatible polysaccharides-based microparticles (MP) to treat the mouse hindlimb ischemia. For this purpose, we deliver the pro-angiogenic chemokine Regulated upon Activation, Normal T-cell Expressed and Secreted (RANTES)/CCL5 in the mouse ischemic hindlimb, in solution or incorporated into polysaccharide-based microparticles. We demonstrate that RANTES-loaded microparticles improve the clinical score, induce the revascularization and the muscle regeneration in injured mice limb. To decipher the mechanisms underlying RANTES effects in vivo, we demonstrate that RANTES increases the spreading, the migration of human endothelial progenitor cells (EPC) and the formation of vascular network. The main receptors of RANTES i.e. CCR5, syndecan-4 and CD44 expressed at endothelial progenitor cell surface are involved in RANTES-induced in vitro biological effects on EPC. By using two RANTES mutants, [E66A]-RANTES with impaired ability to oligomerize, and [44AANA47]-RANTES mutated in the main RANTES-glycosaminoglycan binding site, we demonstrate that both chemokine oligomerization and binding site to glycosaminoglycans are essential for RANTES-induced angiogenesis in vitro. Herein we improved the muscle regeneration and revascularization after RANTES-loaded MP local injection in mice hindlimb ischemia.

Retinoic acid receptor alpha1 variants, RARalpha1DeltaB and RARalpha1DeltaBC, define a new class of nuclear receptor isoforms.

Retinoic acid (RA) binds and activates retinoid X receptor (RXR)/retinoic acid receptor (RAR) heterodimers, which regulate the transcription of genes that have retinoic acid response elements (RARE). The RAR isotypes (alpha, beta and gamma) are comprised of six regions designated A-F. Two isoforms of RARalpha, 1 and 2, have been identified in humans, which have different A regions generated by differential promoter usage and alternative splicing. We have isolated two new splice variants of RARalpha1 from human B lymphocytes. In one of these variants, exon 2 is juxtaposed to exon 5, resulting in an altered reading frame and a stop codon. This variant, designated RARalpha1DeltaB, does not code for a functional receptor. In the second variant, exon 2 is juxtaposed to exon 6, maintaining the reading frame. This isoform, designated RARalpha1DeltaBC, retains most of the functional domains of RARalpha1, but omits the transactivation domain AF-1 and the DNA-binding domain. Consequently, it does not bind nor transactivate RARE on its own. Nevertheless, RARalpha1DeltaBC interacts with RXRalpha and, as an RXRalpha/RARalpha1DeltaBC heterodimer, transactivates the DR5 RARE upon all-trans-RA binding. The use of RAR- and RXR-specific ligands shows that, whereas transactivation of the DR5 RARE through the RXRalpha/RARalpha1 heterodimer is mediated only by RAR ligands, transactivation through the RXRalpha/RARalpha1DeltaBC heterodimer is mediated by RAR and RXR ligands. Whilst RARalpha1 has a broad tissue distribution, RARalpha1DeltaBC has a more heterogeneous distribution, but with significant expression in myeloid cells. RARalpha1DeltaBC is an infrequent example of a functional nuclear receptor which deletes the DNA-binding domain.

Arsenic trioxide and melarsoprol induce apoptosis in plasma cell lines and in plasma cells from myeloma patients.

Recent data have renewed the interest for arsenic-containing compounds as anticancer agents. In particular, arsenic trioxide (As2O3) has been demonstrated to be an effective drug in the treatment of acute promyelocytic leukemia by inducing programmed cell death in leukemic cells both in vitro and in vivo. This prompted us to study the in vitro effects of As2O3 and of another arsenical derivative, the organic compound melarsoprol, on human myeloma cells and on the plasma cell differentiation of normal B cells. At pharmacological concentrations (10(-8) to 10(-6) mol/L), As2O3 and melarsoprol caused a dose- and time-dependent inhibition of survival and growth in myeloma cell lines that was, in some, similar to that of acute promyelocytic leukemia cells. Both arsenical compounds induced plasma cell apoptosis, as assessed by 4',6-diamidino-2-phenylindole staining, detection of phosphatidylserine at the cell surface using annexin V, and by the terminal deoxynucleotidyl transferase-mediated nick end labeling assay. As2O3 and melarsoprol also inhibited viability and growth and induced apoptosis in plasma-cell enriched preparations from the bone marrow or blood of myeloma patients. In nonseparated bone marrow samples, both arsenical compounds triggered death in myeloma cells while sparing most myeloid cells, as demonstrated by double staining with annexin V and CD38 or CD15 antibodies. In primary myeloma cells as in cell lines, interleukin 6 did not prevent arsenic-induced cell death or growth inhibition, and no synergistic effect was observed with IFN-alpha. In contrast to As2O3, melarsoprol only slightly reduced the plasma cell differentiation of normal B cells induced by pokeweed mitogen. Both pokeweed mitogen-induced normal plasma cells and malignant plasma cells showed a normal nuclear distribution of PML protein, which was disrupted by As2O3 but not by melarsoprol, suggesting that the two arsenical derivatives acted by different mechanisms. These results point to the use of arsenical derivatives as investigational drugs in the treatment of multiple myeloma.

18F-FDG labelling of hematopoietic stem cells: Dynamic study of bone marrow homing by PET-CT imaging and impact on cell functionality.

PURPOSE OF THE STUDY: After transplantation, cord blood (CB) hematopoietic stem and progenitor cells (HSPCs) are able to home to the bone marrow niche and to reconstitute the hematopoietic system. PET-CT imaging may be a useful method to monitor this parameter in different conditions. The aim of our study was to set up an efficient method for HSPC radiolabelling with [18F] fluorodeoxyglucose (18F-FDG) and to follow early HSPC homing through PET-CT in mice. MATERIALS AND METHODS: Purified CB HSPCs were radiolabelled with 18F-FDG at 37° C with various conditions of cell concentration, incubation time and radioactivity concentration in order to define the in vitro condition that allows both sufficient 18F-FDG uptake to get high quality PET imaging, and preservation of HSPC viability and functional properties during 3h after radiolabelling. Then, 24h after 2.25Gy irradiation, eight NOD-scid/γc-/- mice were injected with 18F-FDG-labelled HSPCs, the biodistribution of which was followed using micro-PET-CT. RESULTS: The optimal incubation time was 45min with a stability of 48.3%±12.8% after 180min. The radio-uptake rate we obtained was 7.2%±1.7% with an activity of 5.6±2.1 MBq. Three hours after radiolabelling, viability was 96.7%±3.4%. Fifteen hours after radiolabelling, cell viability was 64.0%±2.3%, migration ability diminished from 51.0%±23.6% to 12.0%±9.1%, clonogenic capacity was null, and long-term engraftment in NSG mice also decreased compared to unlabelled cells. Micro-PET-CT experiments showed an accumulation of radiolabelled HSPCs for 2.5h after injection in the bone marrow and a slight elution of 18F-FDG. CONCLUSION: The activity of the obtained 18F-FDG-labelled HSPCs was sufficient to perform the micro-PET-CT imaging. Although the radiolabelling had a significant toxicity on HSPCs 15h after labelling, this technique allowed monitoring the beginning of HSPC homing into the bone marrow.

Esophageal tissue engineering: Current status and perspectives.

Tissue engineering, which consists of the combination and in vivo implantation of elements required for tissue remodeling toward a specific organ phenotype, could be an alternative for classical techniques of esophageal replacement. The current hybrid approach entails creation of an esophageal substitute composed of an acellular matrix and autologous epithelial and muscle cells provides the most successful results. Current research is based on the use of mesenchymal stem cells, whose potential for differentiation and proangioogenic, immune-modulator and anti-inflammatory properties are important assets. In the near future, esophageal substitutes could be constructed from acellular "intelligent matrices" that contain the molecules necessary for tissue regeneration; this should allow circumvention of the implantation step and still obtain standardized in vivo biological responses. At present, tissue engineering applications to esophageal replacement are limited to enlargement plasties with absorbable, non-cellular matrices. Nevertheless, the application of existing clinical techniques for replacement of other organs by tissue engineering in combination with a multiplication of translational research protocols for esophageal replacement in large animals should soon pave the way for health agencies to authorize clinical trials.

A clinical and pharmacological study of arsenic trioxide in advanced multiple myeloma patients.

We previously showed that arsenic trioxide (ATO) and melarsoprol may inhibit the growth of multiple myeloma (MM) cells in vitro and in vivo. We report here the administration of arsenic derivatives in 12 relapsing or refractory secretory MM patients. A total of 10 patients received ATO (eight in a continuous schedule, two discontinuously) and two received melarsoprol. The melarsoprol arm was prematurely closed due to toxicity. In the ATO arm, median duration of treatment was 38 days (9-54). Hepatic toxicity was grade 3 and 2 in one and eight patients, respectively. Other toxicities included neuropathy (n=2, grade 2), encephalitis (n=1, grade 3) and leuconeutropenia (n=4, grade 3). At 2 weeks after treatment initiation, mean serum concentration of arsenic was 1.11+/-0.16 micromol/l. No complete or partial remission was observed. A minor response (25-49% reduction of M protein in serum) and a stabilization of the M-protein level were observed in three and four patients, respectively. After ATO discontinuation, these responses were of short duration in all cases. ATO as a single agent did not produce any significant response in advanced MM patients despite sufficient arsenic exposure. Strategies to improve biodistribution, pharmacokinetic and efficacy of the drug as well as treatment combinations are needed.

Equivalent outcomes using reduced intensity or conventional myeloablative conditioning transplantation for patients aged 35 years and over with AML.

Allogeneic hematopoietic stem cell transplantation provides the best chance of long-term survival for patients with AML, but is associated with an unpredictable risk of treatment-related mortality. From January 2000 to December 2010, we compared the outcomes for patients with AML aged 35 and over using reduced-intensity conditioning (RIC, N=60) or conventional myeloablative conditioning (MAC) regimen (N=72) transplantation. The median follow-up was 47 months (10-134). The 4-year cumulative incidence of non-relapse mortality was 21%. After adjusting for cytogenetic risk, gender donor/recipient mismatch and CD34+ cells, non-relapse mortality was significantly lower with the RIC regimen (P=0.027). The 4-year cumulative incidence of relapse was 38% and no difference was observed in the adjusted relapse rate between the two groups. The 4-year OS rate was 46%. Using both Cox regression and inverse probability-of-treatment weighted (IPTW) method, a similar OS rate was found with both regimens (adjusted hazard ratios for conventional vs reduced of 1.14 (95% CI 0.67-1.93, P=0.64) with Cox regression, and 1.14 (95% CI 0.55-2.34, P=0.73) with IPTW). Until prospective trials are completed, this study supports the use of a reduced-intensity regimen prior to transplantation for patients with AML aged 35 and over.

H RAS mutations in haematologically normal individuals.

INTRODUCTION: Point mutations in N, K and H RAS have been found in adverse haematological malignancies. The background frequency of RAS mutations in the normal population has yet to be determined. Here we report the results of a screen for RAS mutations from normal individuals. MATERIALS AND METHODS: DNA from peripheral blood or bone marrow from 115 haematologically normal individuals was screened for point mutations in N, K and H RAS, at amino acid positions 12, 13 and 61. The screening was done using polymerase chain reaction and oligonucleotide hybridisation and candidate mutations were subsequently confirmed by cloning and sequencing. RESULTS AND CONCLUSION: Point mutations were identified in DNA from two of the 115 individuals. Both mutations resulted in an amino acid substitution at position 12 in H RAS. Both individuals with detectable H RAS mutations remain haematologically normal.

Matched unrelated or matched sibling donors result in comparable outcomes after non-myeloablative HSCT in patients with AML or MDS.

The impact of allelic HLA matching in patients with AML and myelodysplastic syndrome (MDS) who receive allogeneic PBSC after a reduced-intensity conditioning (RIC) regimen is unclear. From January 2000 to December 2010, 108 consecutive patients with AML (n=63) and MDS (n=45) received PBSC after RIC in our center, either from siblings (n=70) or from matched unrelated donors (MUD; 10/10 high resolution, n=38). Conditioning regimen was fludarabine based in 95% of patients and GvHD prophylaxis was mostly cyclosporine plus mycophenolate. Patient characteristics were similar between sibling and MUD for age (median 57 years), gender and disease distribution. Conditioning regimen (more anti-thymocyte globulin (ATG) in MUD), donor age (younger for MUD) and number of CD34+ cells infused (higher in MUD) were different. The median follow-up was 36 months (range 2-72). Engraftment, GvHD, TRM, relapse rate and OS at 3 years were comparable between sibling and MUD. After adjustment for age, cytogenetic risk, ATG and number of CD34+ cells infused, donor type still did not influence OS. In patients with AML or MDS, HSCT from MUD using PBSC after a RIC regimen led to similar outcomes than from Siblings.