Syngeneic Stem Cell Transplantation Research Articles

The late outcomes of syngeneic hematopoietic stem cell transplantation in patients with blood disorders

Introduction. Syngeneic hematopoietic stem cell transplantation is a type of allogeneic stem cell transplantation when the donor of stem cells is a genetically identical (monozygotic) twin of the recipient. After this type of transplantation, there is no immunological conflict as the graft versus host disease, but at the same time, there is no positive effect of the graft-versus-leukemia effect. Aim: to assess the overall survival, event-free survival, probability of relapse, and transplant-related mortality rates associated with syngeneic stem cell transplantation. Patients and methods. In the National Research Center for Hematology from January 1988 to December 2018 we performed 654 allo-HSCT: 17 (2.5%) of them from a syngeneic donor. We performed a «paired analysis» with patients after allo-HSCT from a HLA-identical sibling donor. We included patients after allo-HSCT from an HLA-identical related donor (n = 28) in Group 1 and patients after syngeneic stem cell transplantation in group 2 (n = 14). Patients with aplastic anemia (n = 3) were excluded from the «paired analysis». Results. Patients after syngeneic stem cell transplantation did not develop a graft-versus-host disease. The relapse developed in 50% of cases (n = 7). Five patients (35.7%) died: 4 of them due to the relapse of the disease, and 1 - due to the graft failure. The relapse probability in patients after syngeneic HSCT was higher and amounted to 18.4% versus 54.2% (p = 0.047) for allo-HSCT from HLA-identical sibling donor and a syngeneic donor, respectively. Overall and event-free survival in patients after syngeneic HSCT is comparable to those in patients after allo-HSCT from an HLA-identical sibling donor. Conclusion. Syngeneic hematopoietic stem cell transplantation is justified in the absence of another related or unrelated donor of hematopoietic stem cells. The use of myeloablative conditioning regimens, peripheral blood stem cells as a source of stem cells, or high doses of nucleated cells/kg in the case of using bone marrow will improve post-transplant parameters in patients after syngeneic hematopoietic stem cell transplantation.

Biological versus Clinical Risk Factors in Acute Myeloid Leukemia: Is There a Winner?

We present a case of a patient with a three-month history of peripheral blood cytopenia without a confirmed diagnosis of myelodysplastic syndrome, who developed a favourable-risk acute myeloid leukemia (AML), according to the European Leukemia Net (ELN) criteria. The patient achieved a complete remission with incomplete platelet recovery (CRi) after induction. The patient achieved the morphological CR after the first consolidation and completed the first-line treatment with a syngeneic stem cell transplantation (SCT). A disease relapse occurred after one year of CR (blast cell count in the bone marrow 15%), and the patient was offered a haplo-SCT, which he refused due to personal reasons. In this paper, we discuss the interplay between clinical and biological risk factors in non-high-risk AML patients and speculate that some old clinical risk factors (e.g., age of the patient, achievement of CR after induction, and previous history of myelodysplastic syndrome) may still impact on the treatment decision algorithm of some of these patients.

Graft-versus-host disease targets ovary and causes female infertility in mice

AbstractInfertility associated with ovarian failure is a serious late complication for female survivors of allogeneic hematopoietic stem cell transplantation (SCT). Although pretransplant conditioning regimen has been appreciated as a cause of ovarian failure, increased application of reduced-intensity conditioning allowed us to revisit other factors possibly affecting ovarian function after allogeneic SCT. We have addressed whether donor T-cell-mediated graft-versus-host disease (GVHD) could be causally related to female infertility in mice. Histological evaluation of the ovaries after SCT demonstrated donor T-cell infiltration in close proximity to apoptotic granulosa cells in the ovarian follicles, resulting in impaired follicular hormone production and maturation of ovarian follicles. Mating experiments showed that female recipients of allogeneic SCT deliver significantly fewer newborns than recipients of syngeneic SCT. GVHD-mediated ovary insufficiency and infertility were independent of conditioning. Pharmacologic GVHD prophylaxis protected the ovary from GVHD and preserved fertility. These results demonstrate for the first time that GVHD targets the ovary and impairs ovarian function and fertility and has important clinical implications in young female transplant recipients with nonmalignant diseases, in whom minimally toxic regimens are used.

Recurrent Adult Choroid Plexus Carcinoma Treated with High-Dose Chemotherapy and Syngeneic Stem Cell (Bone Marrow) Transplant

Choroid plexus carcinomas (CPCs) are rare epithelial central nervous system tumors. CPC occurs mainly in infants and young children, comprising ≈ 1 to 4% of all pediatric brain neoplasms. There is very limited information available regarding tumor biology and CPC treatment due to its rarity. There have been various case reports and meta-analyses of reported cases with CPC. Surgical resection is often challenging but remains a well-established treatment option. Chemotherapy is often reserved for recurrent or refractory cases, but the goal of treatment is usually palliative. We present a case of recurrent, adult CPC with disseminated leptomeningeal involvement treated with salvage chemotherapy including high-dose ifosfamide, carboplatin, and etoposide; once a remission was achieved, this response was consolidated with a syngeneic stem cell (bone marrow) transplant after a preparative regimen of high-dose chemotherapy with carboplatin, etoposide, and thiotepa. Although the patient tolerated the transplant well and remained disease-free for 12 months, she subsequently succumbed to relapsed disease 18 months posttransplant. We believe that this is the first report of using syngeneic stem cell transplant in CPC to consolidate a remission achieved by salvage chemotherapy.

Long-term survival following allogeneic or syngeneic stem cell transplant for follicular lymphoma in Sweden

Long-term survival following allogeneic or syngeneic stem cell transplant for follicular lymphoma in Sweden

Allogeneic Non-Adherent Bone Marrow Cells Facilitate Hematopoietic Recovery but Do Not Lead to Allogeneic Engraftment

BackgroundNon adherent bone marrow derived cells (NA-BMCs) have recently been described to give rise to multiple mesenchymal phenotypes and have an impact in tissue regeneration. Therefore, the effects of murine bone marrow derived NA-BMCs were investigated with regard to engraftment capacities in allogeneic and syngeneic stem cell transplantation using transgenic, human CD4+, murine CD4−/−, HLA-DR3+ mice.Methodology/Principal FindingsBone marrow cells were harvested from C57Bl/6 and Balb/c wild-type mice, expanded to NA-BMCs for 4 days and characterized by flow cytometry before transplantation in lethally irradiated recipient mice. Chimerism was detected using flow cytometry for MHC-I (H-2D[b], H-2K[d]), mu/huCD4, and huHLA-DR3). Culturing of bone marrow cells in a dexamethasone containing DMEM medium induced expansion of non adherent cells expressing CD11b, CD45, and CD90. Analysis of the CD45+ showed depletion of CD4+, CD8+, CD19+, and CD117+ cells. Expanded syngeneic and allogeneic NA-BMCs were transplanted into triple transgenic mice. Syngeneic NA-BMCs protected 83% of mice from death (n = 8, CD4+ donor chimerism of 5.8±2.4% [day 40], P<.001). Allogeneic NA-BMCs preserved 62.5% (n = 8) of mice from death without detectable hematopoietic donor chimerism. Transplantation of syngeneic bone marrow cells preserved 100%, transplantation of allogeneic bone marrow cells 33% of mice from death.Conclusions/SignificanceNA-BMCs triggered endogenous hematopoiesis and induced faster recovery compared to bone marrow controls. These findings may be of relevance in the refinement of strategies in the treatment of hematological malignancies.

Plasma Cell Leukemia Maintaining Complete Remission by Syngeneic Stem Cell Transplantation Combined with Low-Dose Thalidomide Maintenance Therapy

Plasma cell leukemia (PCL) is a rare variant of multiple myeloma, which is very aggressive and resistant to chemotherapy. We report a case of PCL successfully treated with syngeneic peripheral blood stem cell transplantation followed by low-dose thalidomide. As of March 2009, the patient has maintained CR for 39 months posttransplant. The clinical course of the present case suggests that autologous stem cell transplantation using a graft with reduced contamination of malignant cells followed by low-dose thalidomide maintenance therapy may improve the PCL treatment outcome.

Stem cell transplantation in rheumatoid arthritis

The therapeutic potential of high dose cytotoxic therapy and stem cell transplantation (SCT) in severe rheumatoid arthritis (RA) was originally supported by animal studies and serendipitous clinical cases where allogeneic and autologous procedures were shown to ameliorate and potentially cure the disease. Phase I and Phase II clinical studies established the feasibility, safety and efficacy of autologous stem cell mobilisation and transplantation. Although it was clear that the effects of high dose chemotherapy and autologous SCT could safely achieve profound responses, sustained control of disease usually required the reintroduction of disease modifying agents. Responses were improved with dose escalation of the conditioning regimen, and also with post-SCT therapy, such as rituximab, but were not observed with graft manipulation. Phase III studies were attempted, but recruitment was compromised by the increasingly widespread use of biological anti-rheumatic agents. Autologous SCT is now only reasonably considered in relatively rare patients whose disease has resisted conventional and biological treatments, and small numbers of cases continue to be registered with the EBMT. Occasional patients treated with allogeneic and syngeneic SCT continue to stimulate academic interest, particularly as some appear to be cured, but significant logistical and toxicity issues mean that routine and widespread application is unrealistic. In summary, SCT continues to have a limited therapeutic potential in rare patients with RA refractory to modern therapy and sufficient fitness for the procedure. From a scientific perspective, ablation of the dysfunctional rheumatoid immune system and its reconstruction with SCT has provided useful insights into the pathophysiology of RA.

Combined Use of Dendritic Cells Enhances Specific Antileukemia Immunity by Leukemia Cell-Derived Heat Shock Protein 70 in a Mouse Model with Minimal Residual Leukemia Cells

We have reported that immunotherapy using leukemia cell-derived heat shock proteins (HSPs) is effective against minimal residual disease (MRD) after syngeneic stem cell transplantation (SCT) in mice. However, leukemia patients after SCT are usually immunocompromised and immunologically tolerant to leukemia cells. We investigated whether the use of dendritic cells (DCs) in combination with HSP70 enhances cytotoxicity against B-cell leukemia cell line A20 in mice after syngeneic SCT. All unimmunized mice died of leukemia early after A20 cell inoculation, whereas mice immunized with HSP70 or HSP70-pulsed DCs survived significantly longer. Although only 60% of the HSP70-immunized mice survived, all mice immunized with HSP70-pulsed DCs survived without MRD. In addition, the cytotoxicities against A20 cells for splenocytes from mice immunized with HSP70-pulsed DCs were significantly higher than those of HSP70-immunized mice, and the cytotoxicities against A20 cells were significantly blocked by anti-CD8 antibody and by major histocompatibility complex class I antibody, but not by anti-CD4 antibody. Moreover, abnormalities were detected in neither the biochemical data nor the histopathologic findings. These findings indicate that the combined use of DCs and leukemia cell-derived HSP70 enhances the antileukemia effect by inducing the specific cytotoxicities of CD8+ cytotoxic T-cells, thereby eradicating MRD effectively and safely, even in an immunocompromised state after syngeneic SCT. This approach may thus be useful for further application of HSP in leukemia patients after autologous SCT.

Critical Role for CCR1:CCL5 (RANTES) Receptor Ligand Interactions in Modulating Allogeneic T Cell Responses Following Bone Marrow Transplantation.

Acute graft versus host disease (GVHD) and leukemic relapse are the most serious complications of allogeneic (allo) stem cell transplantation (SCT), and separating desirable graft-versus-leukemia (GVL) effects from GVHD remains the ultimate challenge to successful outcomes. The recruitment of activated T cells to host target tissues (GVHD) or sites of leukemic infiltration (GVL) is likely mediated by chemokine receptor:ligand interactions. CCR1 is a chemokine receptor that binds to CC chemokines including RANTES (CCL5), and is expressed on a variety of cells including activated T cells, monocytes, and macrophages. We have previously shown that mRNA expression of both CCR1 and RANTES is increased in GVHD target tissues following allo-SCT. Using a well established murine SCT model (B6->B6D2F1) and mice deficient in CCR1, we examined the contribution of CCR1 expression to allo T cell responses in vitro and to GVH and GVL effects in vivo. Lethally (1100cGy) irradiated B6D2F1 mice received SCT either from syngeneic (B6D2F1) or allogeneic (B6) CCR1+/+ or CCR1−/− donors. The severity of GVHD was assessed by survival and a well described clinical scoring system. Syngeneic SCT recipients all survived and were indistinguishable from naïve, untransplanted controls, whereas animals receiving allo-SCT from CCR1+/+ donors developed significant GVHD. By contrast, allo-SCT with CCR1−/− donor cells resulted in significantly improved survival (92% vs. 50%) and less severe clinical GVHD (p<0.01) by day 35 compared to allo-CCR1+/+ controls. GVL effects were next assessed by adding 500 P815 tumor cells (H-2d and syngeneic to host) to the bone marrow inoculum on day 0. F1 recipients of syngeneic BMT all died from tumor infiltration by day +15. Although all allo-SCT recipients effectively rejected their tumor, mice receiving CCR1-/− SCT had significantly improved leukemia free survival (45% vs. 5%) by day 60 compared to allo controls. At higher tumor doses, significant GVL activity remained in CCR1−/− SCT recipients, but the survival advantage was lost. Further examination of allo T cell responses in vivo revealed that day 7 splenic T cell expansion and serum IFNγ levels were significantly lower following CCR1−/− SCT (p < 0.01). Surprisingly, proliferation and IFNγ secretion were also reduced by ~70% when CCR1−/− T cells were stimulated with host antigens in vitro, whereas CTL activity remained equivalent to CCR1+/+ controls. The reduction in proliferation was not secondary to a migration defect, but was dependent on interactions between CCR1 and RANTES; neutralization of RANTES with a monoclonal antibody significantly reduced proliferation of CCR1+/+ T cells in a dose dependent manner. Finally, we found that GVHD mortality was also less when RANTES−/− mice were used as recipients in a second, MHC-disparate, SCT model (p = 0.03). Collectively these data demonstrate a critical role for CCR1 in donor T cell alloreactivity following SCT. These responses contribute to both GVHD and GVL effects in vivo and are likely dependent upon interactions between CCR1 and the chemokine ligand RANTES.

Prospective Monitoring of Tumor Necrosis Factor α and Interferon γ to Predict the Onset of Acute and Chronic Graft-versus-Host Disease after Allogeneic Stem Cell Transplantation

Peripheral blood T cells were isolated from 19 allogeneic and 4 autologous stem cell transplant (SCT) recipients and assessed for tumor necrosis factor (TNF)–α and interferon (IFN)–γ transcription by reverse transcription-polymerase chain reaction. Levels were compared with resting donor T-cell transcription levels. Increased production of TNF-α predicted for the onset of severe (grade II-IV) graft-versus-host disease (GVHD) ( P = .001). Increased TNF-α ( P = .025) and IFN-γ ( P = .001) transcription also independently predicted for the eventual onset of extensive chronic GVHD. Increased TNF-α or IFN-γ transcription was not seen in either a syngeneic SCT recipient or 4 autologous SCT controls. These findings provide a means by which GVHD can be predicted before it is clinically evident, thus allowing for accurate diagnosis and monitoring of GVHD and possibly more cost-effective management of post-SCT immunosuppression.

High-dose chemotherapy and syngeneic stem cell transplantation in a patient with refractory rheumatoid arthritis: poor response associated with persistence of synovial abnormalities

High-dose chemotherapy and syngeneic stem cell transplantation in a patient with refractory rheumatoid arthritis: poor response associated with persistence of synovial abnormalities

Clinical Significance of Minimal Residual Disease in Childhood Acute Myeloid Leukemia

Many studies have assessed the clinical significance of the detection of minimal residual disease (MRD) in acute leukemia. Thus far, many studies have suggested that MRD detection to evaluate the response to chemotherapy is useful for predicting the prognosis of childhood acute lymphoblastic leukemia (ALL). However, few studies have reported on the significance of MRD in childhood acute myeloid leukemia (AML), because of small numbers of patients and limited availability of MRD markers. Therefore, we monitored MRD using currently available markers at several points during the treatment for childhood AML and tried to intensify the treatment based on the results of MRD. Thirty-one patients (26 de novo cases and 5 other cases) were examined for MRD between February 1999 and May 2002. After the first consolidation therapy (consolidation 1), the expression of Wilms tumor gene (WT1) and/or leukemia-specific fusion genes such as AML1/MTG8, PML/RAR alpha, and MYH11/CBF beta were analyzed. Patients with positive MRD but in hematological remission at that point were recommended to undergo stem cell transplantation (SCT). Positive WT1 expression (more than 10(3) copies/microgram RNA) was detected in 18 of 31 patients (58.1%) at onset. After consolidation 1 therapy, the WT1 expression became negative in 14 of 18 patients. The AML1/MTG8 fusion gene was expressed in 8 patients, PML/RAR alpha was expressed in 3 patients, and MYH11/CBF beta was expressed in 1 patient. Four of the 8 patients with AML1/MTG8 expression and all 3 with PML/RAR alpha expression also demonstrated positive WT1 expression at onset. Eight (5 de novo cases and 3 other cases) of the 31 patients had no available MRD markers. Four patients who showed pesistently high expression of WT1 after consolidation 1 therapy underwent SCT, and only 1 patient remained in complete remission (CR). Among 14 patients who became negative for WT1 expression, 6 patients received SCT for various reasons. Among 8 patients with the AML1/MTG8 fusion gene, 2 became MRD negative and 6 continued to be positive. Four of these 6 patients underwent SCT, and all but one who underwent syngeneic SCT became MRD negative. On the other hand, 1 of the 2 patients who continued on chemotherapy continued to be MRD positive, suggesting a graft-versus-leukemia effect in allogeneic SCT. All patients with the PML/RAR alpha and MYH11/CBF beta fusion gene continued to be in CR. The 3-year event-free survival in de novo AML was 69.4% +/- 9.8% (n = 26), a result that is encouraging and superior to other reported outcomes. Thus, an MRD-based treatment strategy together with conventional risk factors appears to be required for further improving the outcomes of AML.

Nonmyeloablative therapy and allogeneic hematopoietic stem cell transplantation.

The toxicities associated with conventional myeloablative therapy and allogeneic hematopoietic stem cell transplantation (SCT) limit the use of this potentially curative approach to relatively healthy young patients. The risk of treatment-related morbidity and mortality with conventional allogeneic SCT ranges from 10% to 50%, depending on the age of the patient, HLA histocompatibility, diagnosis and disease status, and presence or absence of comorbid conditions. The main goals of conventional high-dose preparative regimens are to eradicate the malignancy and induce adequate host immunosuppression to prevent graft rejection. However, accumulated data indicate that the currently used myeloablative regimens frequently do not eradicate the malignant clone, and that an immune-mediated effect between donor immunocompetent T lymphocytes and host tumor cells seems to induce a major therapeutic benefit, accounting for the significantly lower incidence of leukemic relapse seen with allogeneic SCT compared to autologous or syngeneic SCT. These observations have led to the development of newer treatment modalities focusing on the induction of host tolerance to donor cells followed by the administration of scheduled donor T-lymphocyte infusions. Preliminary clinical data are encouraging but need to be confirmed in well-designed prospective controlled trials with direct comparison to conventional allogeneic SCT and extended follow-up to determine the durability of responses and the consequences of late complications such as chronic graft-vs-host disease on the patient's quality of life.

Long-term outcome and quality of life of patients who are alive and in complete remission more than two years after allogeneic and syngeneic stem cell transplantation.

We assessed long-term outcome in 155 patients who had undergone an allogeneic/syngeneic stem cell transplant (SCT) and were in complete remission for more than 2 years after transplant. Probability of late transplant-related mortality was 6%, and affected only patients with chronic graft-versus-host disease (cGVHD). Thirteen percent of patients experienced relapse. Overall survival projected at 10 and 15 years was 83% and 76%, respectively. Secondary malignancies occurred in two patients, 7.5 and 11 years after SCT. Three female and four male patients parented children 19 to 84 months after SCT. Quality of life (QoL) was assessed in a cross-sectional study by the means of a 30-item questionnaire (QLQ-C30) of the EORTC. The questionnaire was sent to 127 patients remaining alive and answered by 106 patients. Seventy-three percent reported a good to very good QoL within 5 years after SCT and 78% after this time point. However, patients with cGVHD had significant impairment of physical, role and social functioning and only 60% of them were fit for work. These results from long-term survivors show that high cure rates with good to very good QoL can be achieved by allogeneic or syngeneic SCT.

Idiotype protein-pulsed dendritic cells produce strong anti-myeloma effects after syngeneic stem cell transplantation in mice.

Dendritic cell (DC) vaccination represents an interesting immunotherapeutic option in the treatment of several malignancies. In multiple myeloma (MM) patients, vaccination with autologous idiotype (Id) protein-pulsed DC is feasible, but their antitumoral effectiveness was rather limited. To improve the therapeutic potential of DC therapy, we studied the immunological effects of syngeneic peripheral blood stem cell transplantation (PBSCT) given in conjunction with Id-loaded DC. Balb/c mice were inoculated i.p. with 5 x 10(5) of HOPC myeloma cells (Balb/c origin). Animals were immunized with three injections of 5 x 10(5) DC pulsed with the IgG2a(HOPC) or with a control immunoglobulin (Ig(control)). Some experimental groups of myeloma-bearing animals received total body irradiation (7.5 Gy) and a subsequent transplant of 2 x 10(7)syngeneic peripheral blood progenitor cells (PBPC) followed by DC therapy beginning at day 10 post transplant. Animals receiving DC therapy or syngeneic PBPCT alone neither induce long-term survival nor tumor-specific CTL reactivity in vitro. In marked contrast, combination of syngeneic PBPC transplantation and subsequent DC therapy resulted in 78% survival after a follow-up of 180 days. In addition, this treatment modality conferred a generation of Id peptide-specific CD8-mediated T cell reactivity. These data provide a rationale for DC-based vaccination in multiple myeloma patients administered post syngeneic transplantation.

Differential short-term and long-term repopulating ability of stem cell subsets in mice.

Hematopoietic reconsitution after transplantation requires the presence of cells with early and late repopulating ability. To determine the contribution of relatively immature and mature hematopoietic progenitor cells in engraftment, we used a modified rhodamine staining procedure to purify populations of rhodamine 123 (Rho)bright, Rhodull and Rho- cells from mouse steady-state bone marrow. Following transplantation of these subsets of stem cells in lethally irradiated mice, marrow repopulating cells were mainly present in the small fraction of Rho- cells, indicating that hematopoietic stem cells have a relatively high expression of P-glycoprotein. Similar cell populations could be purified from cytokine-mobilized blood following treatment with cyclophosphamide and G-CSF. The Rho- cell population contained the majority of hematopoietic stem cells with in vivo marrow repopulating ability. In methylcellulose colony assays, the majority of the committed progenitor cells were present in Rhodull and Rhobright fractions. These results indicate that relatively primitive populations of hematopoietic stem cells that lack colony-forming capacity in vitro mediate the early phase of engraftment following syngeneic stem cell transplantation.