Yu Oyama

Autologous nonmyeloablative hematopoietic stem cell transplantation in patients with severe anti-TNF refractory Crohn disease: long-term follow-up

We evaluated the safety and clinical outcome of autologous nonmyeloablative hematopoietic stem cell transplantation (HSCT) in patients with severe Crohn disease (CD) defined as a Crohn Disease Activity Index (CDAI) greater than 250, and/or Crohn Severity Index greater than 16 despite anti-tumor necrosis factor therapy. Stem cells were mobilized from the peripheral blood using cyclophosphamide (2.0 g/m(2)) and G-CSF (10 μg/kg/day), enriched ex vivo by CD34(+) selection, and reinfused after immune suppressive conditioning with cyclophosphamide (200 mg/kg) and either equine antithymocyte globulin (ATG, 90 mg/kg) or rabbit ATG (6 mg/kg). Eighteen of 24 patients are 5 or more years after transplantation. All patients went into remission with a CDAI less than 150. The percentage of clinical relapse-free survival defined as the percent free of restarting CD medical therapy after transplantation is 91% at 1 year, 63% at 2 years, 57% at 3 years, 39% at 4 years, and 19% at 5 years. The percentage of patients in remission (CDAI < 150), steroid-free, or medication-free at any posttransplantation evaluation interval more than 5 years after transplantation has remained at or greater than 70%, 80%, and 60%, respectively. This trial was registered at www.clinicaltrials.gov as NCT0027853.

Embryonic stem cells as an alternate marrow donor source : engraftment without graft-versus-host disease

A single embryonic stem cell (ESC) line can be repetitively cryopreserved, thawed, expanded, and differentiated into various cellular components serving as a potentially renewable and well-characterized stem cell source. Therefore, we determined whether ESCs could be used to reconstitute marrow and blood in major histocompatibility complex (MHC)-mismatched mice. To induce differentiation toward hematopoietic stem cells (HSCs) in vitro, ESCs were cultured in methylcellulose with stem cell factor, interleukin (IL)-3, and IL-6. ESC-derived, cytokine-induced HSCs (c-kit+/CD45+) were isolated by flow cytometry and injected either intra bone marrow or intravenously into lethally irradiated MHC-mismatched recipient mice. From 2 wk to 6 mo after injection, the peripheral blood demonstrated increasing ESC-derived mononuclear cells that included donor-derived T and B lymphocytes, monocytes, and granulocytes without clinical or histologic evidence of graft-versus-host disease (GVHD). Mixed lymphocyte culture assays demonstrated T cell tolerance to both recipient and donor but intact third party proliferative responses and interferon γ production. ESCs might be used as a renewable alternate marrow donor source that reconstitutes hematopoiesis with intact immune responsiveness without GVHD despite crossing MHC barriers.

Autologous peripheral blood CD133 + cell implantation for limb salvage in patients with critical limb ischemia

We report the safety and feasibility of autologous CD133+ cell implantation into the lower extremity muscles of patients with critical limb ischemia, whose only other option was limb amputation. Nine patients participated in the study: seven patients suffering from arteriosclerosis obliterans, one with thromboangiitis obliterans (Buergers disease) and one with thromboembolic disorder. Autologous PBSC were collected after the administration of G-CSF (10 mcg/kg/day). CD133+ cells were selected using the CLINIMACS cell separation device and were injected i.m. without earlier cryopreservation using a 22-gauge needle into multiple sites 3 cm apart in the gastrocnemius/soleus muscle, or depending on clinical circumstances, in the foot or quadriceps muscle, or both, of the involved leg. There were no complications from either leukapheresis or injection. Stem cell injection prevented leg amputation in seven of the nine patients. In this small cohort of patients with end-stage critical limb ischemia, quality of life (Short Form-36) physical component score improved significantly at 3 (P=0.02) and 6 (P=0.01) months, but not at 1 year (P=0.08). There was a trend towards the improvement in pain-free treadmill walking time (P=0.13) and exercise capacity (P=0.16) at 1 year. Lower extremity limb salvage was achieved for seven of the nine treated patients.

Autologous non-myeloablative hematopoietic stem cell transplantation in patients with systemic sclerosis

Autologous hematopoietic stem cell transplantation (HSCT) utilizing a myeloablative regimen containing total body irradiation has been performed in patients with systemic sclerosis (SSc), but with substantial toxicity. We, therefore, conducted a phase I non-myeloablative autologous HSCT study in 10 patients with SSc and poor prognostic features. PBSC were mobilized with CY and G-CSF. The PBSC graft was cryopreserved without manipulation and re-infused after the patient was treated with a non-myeloablative conditioning regimen of 200 mg/kg CY and 7.5 mg/kg rabbit antithymocyte globulin. There was a statistically significant improvement of modified Rodnan skin score whereas cardiac (ejection fraction, pulmonary arterial pressure), pulmonary function (DLCO) and renal function (creatinine) remained stable without significant change. One patient with advanced disease died 2 years after the transplant from progressive disease. After median follow-up of 25.5 months, the overall and progression-free survival rates are 90 and 70% respectively. Autologous HSCT utilizing a non-myeloablative conditioning regimen appears to result in improved skin flexibility similar to a myeloablative TBI containing regimen, but without the toxicity and risks associated with TBI.

Mobilization, harvesting and selection of peripheral blood stem cells in patients with autoimmune diseases undergoing autologous hematopoietic stem cell transplantation

Peripheral blood stem cells (PBSC) were mobilized in 130 patients with autoimmune diseases undergoing autologous hematopoietic stem cell transplantation using cyclophosphamide 2 g/m2 and either granulocyte colony-stimulating factor (G-CSF) 5 mcg/kg/day (for systemic lupus erythematosus (SLE) and secondary progressive multiple sclerosis, SPMS) or G-CSF 10 mcg/kg/day (for relapsing remitting multiple sclerosis (RRMS), Crohns disease (CD), systemic sclerosis (SSc), and other immune-mediated disorders). Mobilization-related mortality was 0.8% (one of 130) secondary to infection. Circulating peripheral blood (PB) CD34+ cells/μl differed significantly by disease. Collected CD34+ cells/kg/apheresis and overall collection efficiency was significantly better using Spectra apheresis device compared to the Fenwall CS3000 instrument. Patients with SLE and RRMS achieved the lowest and the highest CD34+ cell yields, respectively. Ex vivo CD34+ cell selection employing Isolex 300iv2.5 apparatus was significantly more efficient compared to CEPRATE CS device. Circulating PB CD34+ cells/μl correlated positively with initial CD34+ cells/kg/apheresis and enriched product CD34+ cells/kg. Mean WBC and platelet engraftment (ANC>0.5 × 109/l and platelet count >20 × 109/l) occurred on days 9 and 11, respectively. Infused CD34+ cell/kg dose showed significant direct correlation with faster white blood cell (WBC) and platelet engraftment. When adjusted for CD34+ cell/kg dose, patients treated with a myeloablative regimen had significantly slower WBC and platelet recovery compared to non-myeloablative regimens.

Herpes simplex thymidine kinase gene-transduced donor lymphocyte infusions

OBJECTIVE Donor lymphocytes mediate both a beneficial graft-vs-leukemia/lymphoma (GVL) effect as well as graft-vs-host disease (GVHD), the most dreaded complication of allogeneic hematopoietic stem cell transplantation (HSCT). Transduction of donor lymphocytes with a herpes simplex thymidine kinase (HSVtk) gene prior to infusion confers lethal sensitivity to the anti-herpes drug, ganciclovir (GCV). HSVtk-transduced donor lymphocyte infusions (DLI) have already been used and significant problems have limited the clinical experience to very few patients. To this end, we also report on a study of whether HSVtk-DLI induces GVHD/GVL and if infusion of GCV allows abrogation of GVHD by selective killing of donor lymphocytes. MATERIALS AND METHODS Nine patients with relapsed hematologic malignancies after allogeneic hematopoietic stem cell transplantation (HSCT) were infused with HSVtk gene-modified donor lymphocytes. In brief, transgeneic lymphocytes were prepared by 3 days of activation, 1 day of transduction, 6 days of selection with G418, and 2 to 4 weeks of expansion. RESULTS From 5.0 to 199 x 10(6) CD3(+) DLI were infused. There were no toxicities and no correlation between CD3(+) cell dose and either GVHD or GVL was observed. Only one patient who had cutaneous T-cell lymphoma (CTCL) developed GVHD and that same patient is the only patient to have an anti-tumor response. The patient was infused with 23 x 10(6) CD4(+) and 9.7 x 10(6) CD8(+) HSVtk DLI. Following discontinuation of immune suppression and infusion of GCV, GVHD promptly resolved. Although the CTCL relapsed, it has been easily controlled with intermittent topical therapy. One patient with acute myelogenous leukemia (AML) had a remission inversion of undetermined significance. Two patients with AML, one patient with lymphoma, and four patients with chronic myelogenous leukemia (CML) did not respond. CONCLUSION HSVtk-DLI may provide an anti-tumor effect in vivo and may induce GVHD that is abrogated by GCV treatment. While technical aspects to improve response need to be perfected, HSVtk-DLI infusion to induce a transient GVL/GVHD may become an effective future therapy to minimize complications of allogeneic HSCT.

Hematopoietic Mixed Chimerism Derived from Allogeneic Embryonic Stem Cells Prevents Autoimmune Diabetes Mellitus in NOD Mice

Embryonic stem cell (ESC)‐derived hematopoietic stem cells (HSC), unlike HSC harvested from the blood or marrow, are not contaminated by lymphocytes. We therefore evaluated whether ESC‐derived HSC could produce islet cell tolerance, a phenomenon termed graft versus autoimmunity (GVA), without causing the usual allogeneic hematopoietic stem cell transplant complication, graft‐versus‐host disease (GVHD). Herein, we demonstrate that ESC‐derived HSC may be used to prevent autoimmune diabetes mellitus in NOD mice without GVHD or other adverse side effects. ESC were cultured in vitro to induce differentiation toward HSC, selected for c‐kit expression, and injected either i.v. or intra‐bone marrow (IBM) into sublethally irradiated NOD/LtJ mice. Nine of 10 mice from the IBM group and 5 of 8 from the i.v. group did not become hyperglycemic, in contrast to the control group, in which 8 of 9 mice developed end‐stage diabetes. All mice with >5% donor chimerism remained free of diabetes and insulitis, which was confirmed by histology. Splenocytes from transplanted mice were unresponsive to glutamic acid decarboxylase isoform 65, a diabetic‐specific autoantigen, but responded normally to third‐party antigens. ESC‐derived HSC can induce an islet cell tolerizing GVA effect without GVHD. This study represents the first instance, to our knowledge, of ESC‐derived HSC cells treating disease in an animal model.

Autologous non-myeloablative haematopoietic stem cell transplantation for refractory systemic vasculitis.

Objective: For patients with systemic vasculitis (SV) refractory to conventional therapy, new treatment strategies aimed at aggressive induction of remission and relapse prevention are being sought. We herein report our single-centre experience in treating four patients with refractory SV employing non-myeloablative autologous haematopoietic stem cell transplantation (HSCT). Methods: Four patients with refractory SV (two with neurovascular Behcet disease, one with neurovascular Sjögren syndrome, and one with Wegener granulomatosis) were involved in an Institutional Review Board (IRB) and US Food and Drug Administration (FDA) approved phase I clinical trial of high dose chemotherapy and autologous HSCT. Peripheral blood stem cells were mobilised with cyclophosphamide (Cy) and granulocyte-colony stimulating factor (G-CSF). Conditioning regimen consisted of Cy 200 mg/kg and rabbit anti-thymocyte globulin 5.5 mg/kg intravenously (iv). Results: All four patients tolerated HSCT well without transplant related mortality or any significant toxicity. At median follow-up of 28 (range 22–36) months all patients were alive. Three patients (one with Behcet disease, one with Sjögren syndrome, and one with Wegener granulomatosis) entered a sustained remission at 6, 6 and 24 months, respectively, after transplant. They had significant decrease in disease activity and disease or treatment related damage, as measured by the Birmingham Vasculitis Activity Score and Vasculitis Damage Index, respectively. All three patients who achieved remission discontinued immunosuppressive therapy at the time of transplant and have not required treatment since. One patient with Behcet disease and positive for human leukocyte antigen (HLA)-B51 has not improved after HSCT. Conclusion: We suggest non-myeloablative autologous HSCT is an alternative therapy for select patients with SV refractory to conventional immunosuppressive therapies.

Non-myeloablative stem cell transplantation for autoimmune diseases

Treatment of life-threatening autoimmune diseases in animal models with induced or spontaneous autoimmune diseases can be accomplished by a 2-step procedure involving elimination of self-reactive lymphocytes with an immune ablative conditioning regimen followed by infusion of autologous or allogeneic stem cells, respectively. In animal models it was shown that using such a strategy, autoimmunity could be adequately controlled. It is speculated that de-novo development of the T and B cell repertoire from uncommitted progenitor cells in the presence of the autoantigens may be the best recipe for re-induction of self-tolerance, similarly to the normal ontogeny of the immune system during the induction of self tolerance in fetal stage. For both autologous and allogeneic hematopoietic stem cell transplantation, a non-myeloablative stem cell transplantation (NST) regimen may be used for safer lymphoablation rather than myeloablation. In addition, for allogeneic hematopoietic stem cell transplantation engraftment of disease resistant donor stem cells will alter the genetic predisposition towards autoimmune disease susceptibility.

Hematopoietic stem cell transplantation for severe Crohn's disease

Summary:It is clear that some patients with severe Crohns disease (CD) fail to respond favorably to the standard treatment, including antibody to Tumor Necrosis Factor alpha (TNFα), We have embarked on a unique therapy for this group of patients, intense immune suppression followed by autologous hematopoietic stem cell transplantation (HSCT). The response to this approach in our first four patients has been excellent, with there being no significant untoward event from the transplantation and with each patient entering clinical remission in terms of the Crohns Disease Activity Index off all therapy for CD and no diarrhea or abdominal pain. However, some evidence of minor laboratory abnormalities and slight inflammation of the colon on colonoscopic evaluation persist up to 1 year post-transplant. It is suggested that HSCT should be considered a reasonable option for patients who have failed standard CD therapy, although long-term follow-up will be necessary to confirm the duration of the induced clinical remission.