Loic Fouillard

Mesenchymal stem cells home to injured tissues when co-infused with hematopoietic cells to treat a radiation-induced multi-organ failure syndrome

Recent studies have suggested that ex vivo expansion of autologous hematopoietic cells could be a therapy of choice for the treatment of bone marrow failure. We investigated the potential of a combined infusion of autologous ex vivo expanded hematopoietic cells with mesenchymal (MSCs) for the treatment of multi‐organ failure syndrome following irradiation in a non‐human primate model.

Clinical-grade production of human mesenchymal stromal cells: occurrence of aneuploidy without transformation

Clinical-grade human mesenchymal stromal cells (MSCs) have been expanded in vitro for tissue engineering or immunoregulatory purposes without standardized culture conditions or release criteria. Although human MSCs show poor susceptibility for oncogenic transformation, 2 recent studies described their capacity to accumulate chromosomal instability and to give rise to carcinoma in immunocompromised mice after long-term culture. We thus investigated the immunologic and genetic features of MSCs expanded with fetal calf serum and fibroblast growth factor or with platelet lysate in 4 cell-therapy facilities during 2 multicenter clinical trials. Cultured MSCs showed a moderate expression of human leukocyte antigen-DR without alteration of their low immunogenicity or their immunomodulatory capacity. Moreover, some transient and donor-dependent recurring aneuploidy was detected in vitro, independently of the culture process. However, MSCs with or without chromosomal alterations showed progressive growth arrest and entered senescence without evidence of transformation either in vitro or in vivo.

Hematopoietic stem cell transplantation for multiple sclerosis

Rationale Phase I/II studies of autologous hematopoietic stem cell transplantation (HSCT) for multiple sclerosis (MS) were initiated, based on results of experimental transplantation in animal models of multiple sclerosis and clinical observations in patients treated concomitantly for malignant disease. Patients Eighty-five patients with progressive MS were treated with autologous HSCT in 20 centers and reported to the autoimmune disease working party of the European Group for Blood and Marrow Transplantation (EBMT). 52 (61 %) were female, median age was 39 [20-58] years. The median interval from diagnosis to transplant was 7 [1-26] years. Patients suffered from severe disease with a median EDSS score of 6.5 [4.5-8.5]. Active disease prior to transplant was documented in 79 of 82 evaluable cases. Results The stem cell source was bone marrow in 6 and peripheral blood in 79, and stem cells were mobilized into peripheral blood using either cyclophosphamide combined with growth factors or growth factors alone. Three patients experienced transient neurological complications during the mobilization phase. The high dose regimen included combination chemotherapy, with or without anti-lymphocyte antibodies or, with or without, total body irradiation. The stem cell transplants were purged of lymphocytes in 52 patients. Median follow-up was 16 [3-59] months. There were 7 deaths, 5 due to toxicity and infectious complications, 2 with neurological deterioration. The risk of death of any cause at 3 years was 10 (±7)% (95 % confidence interval). Neurological deterioration during transplant was observed in 22 patients; this was transient in most but was associated with MS progression in 6 patients. Neurological improvement by ≥ 1 point in the EDSS score was seen in 18 (21 %) patients. Confirmed progression-free survival was 74 (±12)% at 3 years being 66 (±23)% in patients with primary progressive MS but higher in patients with secondary progressive or relapsing-remitting MS, 78 (±13)%; p = 0.59. The probability of confirmed disease progression was 20 (±11)%. MRI data were available in 78 patients before transplant showing disease activity (gadolinium enhancing, new or enlarging lesions) in 33 %. Posttransplant MRI showed activity at any time in 5/61 (8 %) evaluable cases. Conclusion Autologous HSCT suggest positive early results in the management of progressive MS and is feasible. These multicentre data suggest an association with significant mortality risks especially in some patient groups and are being utilised in the planning of future trials to reduce transplant related mortality.

Autologous stem cell transplantation for systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is responsive to treatment with immunosuppressives and steroids, but often pursues a relapsing or refractory course resulting in increasing incapacity and reduced survival. Autologous stem cell transplantation (ASCT) following immunoablative chemotherapy is a newer therapy for autoimmune disease of potential use in severe SLE. A retrospective registry survey was carried out by the European Blood and Marrow Transplant and European League Against Rheumatism (EBMT/EULAR) registry. Data was collected from 53 patients with SLE treated by ASCT in 23 centres. Disease duration before ASCT was 59 (2-155) months (median, range), 44 (83%) were female, and median age was 29 (9-52) years. At the time of ASCT a median of seven American College of Rheumatology (ACR) diagnostic criteria for SLE were present (range 2-10) and 33 (62%) had nephritis. Peripheral blood stem cells were mobilized with cyclophosphamide and granulocyte colony stimulating factor in 93% of cases. Ex vivo CD34 stem cell selection was performed in 42% of patients. Conditioning regimens employed cyclophosphamide in 84%, anti-thymocyte globulin in 76% and lymphoid irradiation in 22%. The mean duration of follow-up after ASCT was 26 (0-78) months. Remission of disease activity (SLEDAI < 3) was seen in 33/50 (66%; 95%CI 52-80) evaluable patients by six months, of which 10/31 (32%; 95%CI 15-50) subsequentlyrelapsed after six (3-40) months. Relapse was associated with negative anti-double stranded DNA (anti-dsDNA) antibodies before ASCT (P 0.007). There were 12 deaths after 1.5 (0-48) months, of which seven (12%; 95%CI 3-21) were related to the procedure. Mortality was associated with a longer disease course before ASCT (P 0.036). In conclusion, this registry study demonstrates the efficacy of ASCT for remission induction of refractory SLE, although mortality appeared high. The safety of this procedure is likely to be improved by patient selection and choice of conditioning regimen. The return of disease activity in one-third of patients might be reduced by long-term immunosuppressive therapy post-ASCT.

Autologous stem cell transplantation for progressive multiple sclerosis : Update of the European Group for Blood and Marrow Transplantation autoimmune diseases working party database

Over the last decade, hematopoietic stem cells transplantation (HSCT) has been increasingly used in the treatment of severe progressive autoimmune diseases. We report a retrospective survey of 183 multiple sclerosis (MS) patients, recorded in the database of the European Blood and Marrow Transplantation Group (EBMT). Transplant data were available from 178 patients who received an autologous graft. Overall, transplant related mortality (TRM) was 5.3% and was restricted to the period 1995-2000, with no further TRM reported since then. Busulphan-based regimens were significantly associated with TRM. Clinical status at the time of transplant and transplant techniques showed some correlations with toxicity. No toxic deaths were reported among the 53 patients treated with the BEAM (carmustine, etoposide, cytosine-arabinoside, melphalan)/antithymocyte globulin (ATG) regimen without graft manipulation, irrespective of their clinical condition at the time of the transplant. Improvement or stabilization of neurological conditions occurred in 63% of patients at a median follow-up of 41.7 months, and was not associated with the intensity of the conditioning regimen. In this large series, HSCT was shown as a promising procedure to slow down progression in a subset of patients affected by severe, progressive MS; the safety and feasibility of the procedure can be significantly improved by appropriate patient selection and choice of transplant regimen.

Use of Mesenchymal Stem Cells (MSC) in Chronic Inflammatory Fistulizing and Fibrotic Diseases: a Comprehensive Review

Mesenchymal stem cells (MSC), multipotent adult stem cells, feature the potential to regenerate tissue damage and, in parallel, inhibit inflammation and fibrosis. MSC can be safely transplanted in autologous and allogeneic ways as they are non-immunogenic, and consequently represent a therapeutic option for refractory connective tissue diseases, fibrosing diseases like scleroderma and fistulizing colitis like in Crohn’s disease. Actually, there are more than 200 registered clinical trial sites for evaluating MSC therapy, and 22 are on autoimmune diseases. In irradiation-induced colitis, MSC accelerate functional recovery of the intestine and dampen the systemic inflammatory response. In order to provide rescue therapy for accidentally over-irradiated prostate cancer patients who underwent radiotherapy, allogeneic bone marrow-derived MSC from family donors were intravenously infused to three patients with refractory and fistulizing colitis resembling fistulizing Crohn’s disease. Systemic MSC therapy of refractory irradiation-induced colitis was safe and effective on pain, diarrhoea, hemorrhage, inflammation and fistulization accompanied by modulation of the lymphocyte subsets towards an increase of T regulatory cells and a decrease of activated effector T cells. The current data indicate that MSC represent a promising alternative strategy in the treatment of various immune-mediated diseases. Encouraging results have already been obtained from clinical trials in Crohn’s disease and SLE as well as from case series in systemic sclerosis. MSC represent a safe therapeutic measure for patients who suffer from chronic and fistulizing colitis. These findings are instructional for the management of refractory inflammatory bowel diseases that are characterized by similar clinical and immunopathological features.

Higher Incidence of Relapse With Peripheral Blood Rather Than Marrow As a Source of Stem Cells in Adults With Acute Myelocytic Leukemia Autografted During the First Remission

PURPOSE The cell source for autologous stem cell transplantation has shifted from bone marrow (BM) to peripheral blood (PB). In acute myelocytic leukemia (AML), for patients who receive transplants during first complete remission (CR1), no prospective randomized study has compared relapse incidence (RI) to cell source. PATIENTS AND METHODS We analyzed 2,165 patients who received autografts (1,607 PB and 558 BM) from 1994 to 2006 and were reported to the European Cooperative Group for Blood and Marrow Transplantation with complete research data. Relative to the time of CR1, PB transplants were performed earlier than BM transplants. Because a poorer outcome was associated with a shorter interval from CR1 to transplantation, patients were divided into three groups: BM, early PB (< or = 80 days after CR1), and late PB (> 80 days after CR1) transplantation. RESULTS In a multivariate analysis adjusted for differences between groups and center, RI was higher with both early PB (56% +/- 3%; hazard ratio [HR], 1.45; 95% CI, 1.11 to 1.9; P = .006) and late PB transplantation (46% +/- 2%; HR, 1.3; 95% CI, 1.06 to 1.59; P = .01) as compared with BM transplantation (39% +/- 2%). This translated into a significantly worse leukemia-free survival (LFS) for early PB transplantation (36% +/- 3%; HR, 0.75; 95% CI, 0.58 to 0.96; P = .02) and a trend for a poorer LFS for late PB (46% +/- 2%; HR, 0.84; 95% CI, 0.7 to 1.01; P = .06) as compared with BM (52% +/- 2%). CONCLUSION For patients with AML in CR1, risk of relapse is greater with PB transplantation rather than BM, independent of the interval from CR1 to transplantation.

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

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

Results of syngeneic hematopoietic stem cell transplantation for acute leukemia: risk factors for outcomes of adults transplanted in first complete remission

Background The possibility of performing syngeneic hematopoietic stem cell transplantation is rare and there are concerns about the absence of a graft-versus-leukemia effect following such a strategy. We report the outcomes of a large series of adult patients who underwent syngeneic hematopoietic stem cell transplantation for acute myeloblastic leukemia or acute lymphoblastic leukemia. Design and Methods The outcomes of all syngeneic transplants for acute myeloblastic or lymphoblastic leukemia reported to the European Group for Blood and Marrow Transplantation registry were analyzed; a study of prognostic factors was performed for those transplanted in first complete remission. Results One hundred and sixty-two patients, 109 with acute myeloblastic leukemia and 53 with acute lymphoblastic leukemia, were identified; 116 were in first complete remission. Most of the patients did not receive prophylaxis against graft-versus-host disease. Nineteen patients developed acute graft-versus-host disease and only three patients developed chronic graft-versus-host disease. The median follow-up was 60 months. At 5 years the non-relapse mortality was 8±5%, the relapse incidence 49±8% and the leukemia-free survival 43±3%. The corresponding figures for patients in first complete remission were 7±2%, 40±4% and 53±5% at 5 years. Analysis of patients in first complete remission showed that the number of courses of chemotherapy required to induce first complete remission was the main risk factor: the leukemia-free survival at 5 years was 66±6% when first complete remission was reached after one induction course of chemotherapy and was only 20±9% when first complete remission was reached after at least two induction courses of chemotherapy (p=0.0001); the relapse incidence was 30±6% and 54±10%, respectively (p=0.007). Conclusions Outcomes were better for patients transplanted in first complete remission than in second complete remission or a more advanced phase of the disease. When a syngeneic donor is available for patients with high risk acute leukemia, allotransplantation should be performed as soon as the first complete remission has been achieved, ideally with one course of chemotherapy.

Innovative cell therapy in the treatment of serious adverse events related to both chemo-radiotherapy protocol and acute myeloid leukemia syndrome: the infusion of mesenchymal stem cells post-treatment reduces hematopoietic toxicity and promotes hematopoietic reconstitution.

Bone marrow stroma is damaged by chemotherapy and irradiation protocol. Bone marrow microenvironment supports haematopoiesis and comprises Mesenchymal Stem Cells (MSCs). Coinfusion of MSCs with hematopoietic stem cells (HSC) improves engraftment and accelerates haematopoietic recovery. Stroma-derived factor-1 (SDF-1) is a chemotactic factor which plays a crucial role in stem cell transplantation by enhancing the ability of HSC to engraft. In this study expression of SDF-1 in bone marrow MSCs and the level of Colony Forming Unit Fibroblast (CFU-F) were evaluated in 8 patients with Acute Myeloid leukemia (AML). Evaluation was done at diagnosis and after induction/consolidation chemotherapy before the onset of haematopoietic stem cell transplantation (HSCT). CFU-F frequency increases from diagnosis to remission. Nevertheless level of stromal derived factor-1 (SDF-1) transcripts in bone marrow MSCs of patients with AML stays low. Considering the role of SDF-1 in the homing of HSC, the consequences of SDF-1 deficiency observed in this study might be deleterious on the engraftment after HSCT and haematopoietic recovery. The whole result of this clinical study is an argument for MSC infusion to restore a normal level of SDF1 in the bone marrow microenvironment that could reduce hematopoietic toxicity of chemotherapy and improve HSC engraftment after HSCT.