Co-transfusion of haplo-identical hematopoietic and mesenchymal stromal cells to treat a patient with severe aplastic

Combination of Haploidentical Hematopoietic Stem Cell Transplantation with Umbilical Cord-Derived Mesenchymal Stem Cells in Patients with Severe Aplastic Anemia: a Retrospective, Controlled Study

Objective:

We retrospectively compared the outcomes of patients with severe aplastic anemia (SAA) who received haploidentical hematopoietic stem cell transplantation (haplo-HSCT) combined or not combined with umbilical cord-derived mesenchymal stem cells (UC-MSCs).

Materials and Methods:

A total of 101 patients with SAA were enrolled in this study and treated with haplo-HSCT plus UC-MSC infusion (MSC group, n=47) or haplo-HSCT alone (non-MSC group, n=54).

Results:

The median time to neutrophil engraftment in the MSC and non-MSC group was 11 (range: 8-19) and 12 (range: 8-23) days, respectively (p=0.049), with a respective cumulative incidence (CI) of 97.82% and 97.96% (p=0.101). Compared to the non-MSC group, the MSC group had a lower CI of chronic graft-versus-host disease (GVHD) (8.60±0.25% vs. 24.57±0.48%, p=0.048), but similar rates of grades II-IV acute GVHD (23.40±0.39% vs. 24.49±0.39%, p=0.849), grades III-IV acute GVHD (8.51±0.17% vs. 10.20±0.19%, p=0.765), and moderate-severe chronic GVHD (2.38±0.06% vs. 7.45±0.18%, p=0.352) were observed. The estimated 5-year overall survival (OS) rates were 78.3±6.1% and 70.1±6.3% (p=0.292) while the estimated 5-year GVHD-free, failure-free survival (GFFS) rates were 76.6±6.2% and 56.7±6.9% (p=0.045) in the MSC and non-MSC groups, respectively.

Conclusion:

In multivariate analysis, graft failure was the only adverse predictor for OS. Meanwhile, graft failure, grades III-IV acute GVHD, and moderate-severe chronic GVHD could predict worse GFFS. Our results indicated that haplo-HSCT combined with UC-MSCs infusion was an effective and safe option for SAA patients.

Exosomes derived from mesenchymal stem cells regulate Treg/Th17 balance in aplastic anemia by transferring miR-23a-3p

Imbalanced Th17/Treg ratio is implicated in the pathogenesis of aplastic anemia. Studies have indicated that bone marrow-derived mesenchymal stem cells-derived exosomes (BMSC-Exo) could correct imbalanced Th17/Treg in aplastic anemia, but the mechanism remains not fully understand. This study was designed to investigate whether BMSC-Exo regulates the Th17/Treg balance in aplastic anemia by transferring miR-23a-3p. Here, miR-23a-3p inhibitor was utilized to knockdown the expression of miR-23a-3p in BMSC-Exo. A co-culture system of CD4⁺ T cells from aplastic anemia patients and BMSC-Exo was used to explore the effects of BMSC-Exo on the Th17/Treg balance and the underlying mechanism in aplastic anemia. The patients with aplastic anemia exhibited Th17/Treg imbalance favoring the Th17 cells. BMSC-Exo could balance the percentage of Th17 and Treg cells in aplastic anemia, but the effects of BMSC-Exo can be eliminated when miR-23a-3p expression was silenced in BMSCs. IL-6 was a direct target of miR-23a-3p. IL-6 overexpression could abrogate BMSC-Exo-induced balance in Th17/Treg ratio. Overall, BMSC-Exo could balance Th17/Treg ratio in aplastic anemia via suppressing IL-6 expression by transferring miR-23a-3p at least in part. These data indicated miR-23a-3p may be a potential target for the treatment of aplastic anemia. Our study may provide a new idea for the therapy of the disease.

A study of human leukocyte antigen-haploidentical hematopoietic stem cells transplantation combined with allogenic mesenchymal stem cell infusion for treatment of severe aplastic anemia in pediatric and adolescent patients

The clinical applications of human leukocyte antigen (HLA) haploidentical hematopoietic stem cells transplantation (haplo‐HSCT) have offered most of the young severe aplastic anemia (SAA) patients an opportunity to accept curative therapy at the early stage of bone marrow lesions. However, the outcome of juvenile SAA patients received haplo‐HSCT remain to be improved due to high incidence of graft failure and graft vs host disease (GVHD). Mesenchymal stem cells (MSCs) have been characterized by their hematopoiesis‐supporting and immunomodulatory properties. In the current study, we designed a combination of haplo‐HSCT with allogenic MSC for treatment of SAA in pediatric and adolescent patients and evaluated its effects. Juvenile patients (<18 years) with SAA (n = 103) were given HLA‐haploidentical HSC combined with allogenic MSC after a conditioning regimen consisting of busulfan, cyclophosphamide, fludarabine, and antithymocyte globulin and an intensive GVHD prophylaxis, including cyclosporine, short‐term methotrexate, mycophenolate mofetil, and basiliximab. Neutrophil engraftment was achieved in 102 of 103 patients in a median time of 14.3 days (range 9‐25 days). The median time of platelet engraftment was 25.42 days (range 8‐93 days). The cumulative incidence of II‐IV acute GVHD at day +100 was 26.32% ± 0.19% and III‐IV acute GVHD was 6.79% ± 0.06% at day +100, respectively. The cumulative incidence of chronic GVHD was 25.56% ± 0.26%. The overall survival was 87.15% ± 3.3% at a median follow‐up of 40 (1.3‐98) months. Our data suggest that cotransplantation of HLA‐haploidentical HSC and allogenic mesenchymal stem cell may provide an effective and safe treatment for children and adolescents with SAA who lack matched donors.

Effect of Stem Cell Source and Dose on Allogeneic Hematopoietic Stem Cell Transplantation in Adult Patients with Idiopathic Aplastic Anemia: Data from the Korean Aplastic Anemia Trials

OBJECTIVE

We aimed to evaluate the effect of stem cell source and dose on the survival of various donor subgroups, such as matched sibling donor (MSDs) and alternative donors (ADs), upon bone marrow (BM) or peripheral blood stem cell (PBSC) infusion in aplastic anemia (AA).

METHODS

We retrospectively investigated the effects of stem cell source and dose on allogeneic hematopoietic stem cell transplantation (alloHSCT) in AA.

RESULTS

A total of 267 patients were included in this analysis. The BM-treated group showed an association with low incidence of any-grade acute graft versus host disease (GvHD) (p < 0.001). A higher stem cell dose was related with a low incidence of extensive chronic GvHD in MSDs (p = 0.025). Multivariate analysis for overall survival (OS) revealed that only age at alloHSCT <31 years (p = 0.010) and prior platelet transfusion <86 U (p = 0.046) in MSDs and higher stem cell dose (hazard ratio = 2.596, p = 0.045) in ADs were favorable prognostic factors.

CONCLUSION

PBSCs could be preferred in AD because high stem cell dose may be easily achieved to improve the OS at the expense of acute GvHD. However, BM stem cells are preferred in MSDs.

Therapeutic Outcomes of Haploidentical Allogeneic Hematopoietic Stem Cell Transplantation in Patients With Severe Aplastic Anemia: A Multicenter Study

BACKGROUND

Haploidentical donor (HID) allogeneic hematopoietic stem cell transplantation (HSCT) is an alternative curative treatment for patients with severe aplastic anemia (SAA) who do not have suitable matched related donors (MRD). The aim of this study was to compare the therapeutic outcomes of HID-HSCT with those of MRD-HSCT for SAA.

METHODS

A total of 235 SAA patients who underwent HID-HSCT (116) or MRD-HSCT (119) at 11 transplantation centers from January 2007 to January 2016 were included. Complications and survival outcomes were evaluated and compared between the 2 groups.

RESULTS

The HID group had a lower incidence of secondary graft failure but higher incidences of acute graft-versus-host disease (aGVHD) and chronic GVHD (cGVHD). However, the incidence of severe aGVHD (grades III-IV), poor graft function, and infections was comparable between groups. Patients in the HID group had a significantly lower survival and overall survival rates than those in the MRD group. The estimated 3-year survival rates for the MRD and HID groups were 82.82% and 75.00%, respectively. Ferritin levels, graft failure, poor graft function, severe aGVHD, and infections were the significant risk factors for survival.

CONCLUSIONS

The overall survival rate is acceptable for patients who underwent HID-HSCT, making it a feasible treatment choice for SAA patients.

[The mechanism of bone marrow-derived mesenchymal stem cells excessive senescence in severe aplastic anemia mouse model]

Objective: To explore the mechanism of excessive senescence in bone marrow-derived mesenchymal stem cells (BM-MSC) of mouse model with severe aplastic anemia (SAA) . Methods: 40 BALB/c mice were randomly assigned to two groups of control (n=20) and AA (n=20) . SAA mouse model was induced by intraperitoneal injection with IFN-γ and intragastric infusion with busulfan. BM-MSC were isolated and cultured from bone marrow of SAA and healthy mice. The cell morphology was observed by inverted microscope and cell cytoskeleton was stained by Rhodamine-Phalloidin; The level of proliferation was analyzed by CCK-8 method, and cell cycle was tested by flow cytometry. Senescence-associated β-galactosidase (SA-β-gal) assay was used to detect senescent BM-MSC; The expression of mTOR protein was detected by Western blot method. Results: BM-MSC from normal mice presented spindle-shaped, clear boundaries and stress fibers were arranged in parallel, neat. while BM-MSCs from SAA mice presented cell volume increases, tiled, ill-shaped and the stress fiber appeared to be disordered. The decreased activity of proliferation [more cells restricted in G(0)/G(1) phase [ (77.461±1.567) % vs (46.045±2.055) %, t=-34.384, P<0.001], increased percentage of SA-β-gal positive cells [ (75±11) % vs (28±8) %, t=15.454, P<0.001] and notably enhanced expression of mTOR of BM-MSC from SAA mice were observed when compared with those from normal mice. Conclusion: This study clarified senescent BM-MSCs from SAA model mice, which could be caused by the excessive activation of mTOR pathway.

In patients with chronic aplastic anemia, bone marrow-derived MSCs regulate the Treg/Th17 balance by influencing the Notch/RBP-J/FOXP3/RORγt pathway

The standard treatment for aplastic anemia (AA) in young patients is a matched sibling hematopoietic stem cell transplant. Transfusion of a chronic AA patient with allogeneic bone marrow–derived mesenchymal stromal cells (BMMSCs) is currently being developed as a cell-based therapy, and the safety and efficacy of such transfusions are being continuously improved. Nevertheless, the mechanisms by which BMMSCs exert their therapeutic effects remain to be elucidated. In this study, mesenchymal stromal cells (MSCs) obtained from bone marrow donors were concentrated and intravenously injected into 15 chronic AA patients who had been refractory to prior immunosuppressive therapy. We showed that BMMSCs modulate the levels of Th1, Th2, Th17 and Treg cells, as well as their related cytokines in chronic AA patients. Furthermore, the percentages of Th1 and Th17 cells among the H-MSCs decreased significantly, while the percentage Treg cells increased. The Notch/RBP-J/FOXP3/RORγt pathway was involved in modulating the Treg/Th17 balance after MSCs were transfused in vitro. Additionally, the role played by transfused MSCs in regulating the Treg/Th17 balance via the Notch/RBP-J/FOXP3/RORγt pathway was further confirmed in an AA mouse model. In summary, in humans with chronic AA, BMMSCs regulate the Treg/Th17 balance by affecting the Notch/RBP-J/FOXP3/RORγt pathway.

Comparable Allogeneic Hematopoietic Cell Transplantation Outcome of a Haplo-Identical Family Donor with an Alternative Donor in Adult Aplastic Anemia

We performed a study on allogeneic hematopoietic cell transplantation (alloHCT) from an HLA-haplo-identical familial donor (haploFD) using a busulfan-fludarabine-antithymocyte globulin conditioning regimen for severe aplastic anemia (sAA) and hypoplastic myelodysplastic syndrome. For the comparison between a haploFD and an alternative donor (AD; matched unrelated or partially matched donor) for sAA in adults, we collected haploFD data retrospectively and prospectively. Forty-eight AD cases were selected for the comparison with 16 haploFD cases. All transplantation outcomes except for extensive chronic graft versus host disease (GvHD) were similar. The frequencies of hepatic sinusoidal obstruction syndrome (p = 1.000), acute GvHD (p = 0.769), grade 3/4 acute GvHD (p = 0.258), chronic GvHD (p = 0.173), extensive chronic GvHD (p = 0.099), primary neutrophil engraftment failure (p = 1.000), secondary graft failure (p = 1.000) and platelet engraftment failure (p = 0.505) were similar. Time to neutrophil engraftment was faster in haploFD (p = 0.003), while the cumulative incidence of platelet engraftment was similar (p = 0.505). Overall survival was also similar between AD and haploFD (p = 0.730). In conclusion, alloHCT from haploFD in sAA was comparable with alloHCT from AD, but extensive chronic GvHD seemed frequent in haploFD. Therefore alloHCT from haploFD could be an alternative approach for alloHCT from AD in adult sAA.

Haploidentical parental hematopoietic stem cell transplantation in pediatric refractory Langerhans cell histiocytosis

Children with MS-LCH that fail to respond to conventional chemotherapy have poor outcomes. HSCT represents a potential salvage approach. It has been applied in over 50 cases in recent years. HSCT can achieve greater disease control than chemotherapy, but it carries a high risk of transplant-related mortality; thus, the haploidentical parental HSCT is used infrequently in pediatric refractory LCH. We report the first successful haploidentical parental HSCT, with no T-cell depletion, in two girls, aged 26 months and five months, with refractory MS-LCH. The mothers were donors with 5/6 and 4/6 HLA matches, respectively. The conditioning regimen included busulfan + cyclophosphamide + etoposide + antithymocyte-globulin ± fludarabine; the GVHD prophylaxis was based on cyclosporine + methotrexate ± mycophenolate-mofetil ± zenapax. In both cases, the stem cells were sourced from peripheral blood and BM, which included CD34+ cells (13.17 × 10(6)/kg and 40.23 × 10(6)/kg, respectively). These patients survived and showed no signs of disease activity in 54- and 44-month post-HSCT follow-ups. Our results indicated that, for patients that fail chemotherapy delivered early in the disease, but do not show organ dysfunction progression, it may be possible to achieve successful haploidentical parental HSCT with a strong myeloablative regimen.

Bone marrow mesenchymal stem cells from patients with aplastic anemia maintain functional and immune properties and do not contribute to the pathogenesis of the disease

Aplastic anemia is a life-threatening bone marrow failure disorder characterized by peripheral pancytopenia and marrow hypoplasia. The majority of cases of aplastic anemia remain idiopathic, although hematopoietic stem cell deficiency and impaired immune responses are hallmarks underlying the bone marrow failure in this condition. Mesenchymal stem/stromal cells constitute an essential component of the bone marrow hematopoietic microenvironment because of their immunomodulatory properties and their ability to support hematopoiesis, and they have been involved in the pathogenesis of several hematologic malignancies. We investigated whether bone marrow mesenchymal stem cells contribute, directly or indirectly, to the pathogenesis of aplastic anemia. We found that mesenchymal stem cell cultures can be established from the bone marrow of aplastic anemia patients and display the same phenotype and differentiation potential as their counterparts from normal bone marrow. Mesenchymal stem cells from aplastic anemia patients support the in vitro homeostasis and the in vivo repopulating function of CD34(+) cells, and maintain their immunosuppressive and anti-inflammatory properties. These data demonstrate that bone marrow mesenchymal stem cells from patients with aplastic anemia do not have impaired functional and immunological properties, suggesting that they do not contribute to the pathogenesis of the disease.

Functional mesenchymal stem cells remain present in bone marrow microenvironment of patients with leukemia post-allogeneic hematopoietic stem cell transplant

Mesenchymal stem cells (MSCs) and their progenies are important supporting cells in the bone marrow (BM) microenvironment. However, the function and kinetics of MSCs post-hematopoietic stem cell transplant (HSCT) remain unknown. In the present study, MSCs were cultured from a total of 76 BM samples from 15 patients receiving HSCT. Colony-forming unit fibroblasts in BM before pre-conditioning and 1, 3, 6 and 9 months post-HSCT were cultured and counted to quantify MSCs. Hematopoiesis-supporting activity of MSCs was observed with long-term culture of hematopoietic progenitors. An inhibitory effect of MSCs on in vitro lymphocyte proliferation was also observed. Results showed that post-HSCT MSCs supported in vitro hematopoiesis and inhibited lymphocyte growth. Moreover, the quantity of MSCs was reduced at an early stage and restored to baseline level 9 months post-transplant. The results indicate that functional MSCs remain present in the BM microenvironment, and these findings shed light on the understanding of BM microenvironment reconstitution post-HSCT.

Efficacy and safety of mesenchymal stromal cell treatment from related donors for patients with refractory aplastic anemia

BACKGROUND AIMS

This study evaluated the feasibility, safety and immunological effects of the intravenous administration of mesenchymal stromal cells (MSCs) from a related donor in patients with refractory aplastic anemia (AA).

METHODS

A mean of 6 × 10(5)/kg (range, 5.0-7.1 × 10(5)) MSCs were injected intravenously to 18 patients, including 14 patients with nonsevere AA and four patients with severe AA who were refractory to prior immunosuppressive treatment. The outcomes of patients treated with MSCs were evaluated and compared with a historic control cohort, including 18 patients with refractory AA.

RESULTS

Two patients had injection-related adverse events, including transient fever and headache. No major adverse events were reported during the follow-up period. An immunological analysis revealed an increased proportion of CD4(+)CD25(+) FOXP3(+)regulatory T cells in peripheral mononuclear cells. Following up for 1 year, six of 18 patients (33.3%) achieved a complete response or a partial response to MSC treatment. In six patients, two achieved a complete response including a recovery of three hematopoietic cell lines after MSCs therapy at days 88 and 92, two patients achieved only a red cell recovery with hemoglobin levels >100 g/L at days 30 and 48 and two patients had only a platelet recovery with a platelet count of >60 × 10(9)/L at days 54 and 81. In the control cohort, only one patient (5.56%) achieved a partial response during the follow-up period.

CONCLUSIONS

The data from the present study suggest that treatment with MSCs from a related donor may be a promising therapeutic strategy for patients with refractory AA. The trial has been registered at ClinicalTrials.gov: identifier NCT01305694.

Differential gene expression profile associated with the abnormality of bone marrow mesenchymal stem cells in aplastic anemia

Aplastic anemia (AA) is generally considered as an immune-mediated bone marrow failure syndrome with defective hematopoietic stem cells (HSCs) and marrow microenvironment. Previous studies have demonstrated the defective HSCs and aberrant T cellular-immunity in AA using a microarray approach. However, little is known about the overall specialty of bone marrow mesenchymal stem cells (BM-MSCs). In the present study, we comprehensively compared the biological features and gene expression profile of BM-MSCs between AA patients and healthy volunteers. In comparison with healthy controls, BM-MSCs from AA patients showed aberrant morphology, decreased proliferation and clonogenic potential and increased apoptosis. BM-MSCs from AA patients were susceptible to be induced to differentiate into adipocytes but more difficult to differentiate into osteoblasts. Consistent with abnormal biological features, a large number of genes implicated in cell cycle, cell division, proliferation, chemotaxis and hematopoietic cell lineage showed markedly decreased expression in BM-MSCs from AA patients. Conversely, more related genes with apoptosis, adipogenesis and immune response showed increased expression in BM-MSCs from AA patients. The gene expression profile of BM-MSCs further confirmed the abnormal biological properties and provided significant evidence for the possible mechanism of the destruction of the bone marrow microenvironment in AA.

Impaired immunomodulatory ability of bone marrow mesenchymal stem cells on CD4(+) T cells in aplastic anemia

Aplastic anemia (AA) is a marrow failure syndrome mediated by aberrant T-cell subsets. Mesenchymal stem cells (MSCs) play an important role in maintaining immune homeostasis through modulating a variety of immune cells. However, little is known about the immunomodulation potential of bone marrow MSCs (BM-MSCs) in AA. Here, we reported that BM-MSCs from AA patients were reduced in suppressing the proliferation and clonogenic potential of CD4(+) T cells and the production of tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), which was associated with decreased prostaglandin E2 (PGE2). Meanwhile, BM-MSCs from AA patients were defective to promote CD4(+)CD25(+)FOXP3(+) regulatory T cells expansion through reduced transforming growth factor-β (TGF-β). No significant difference between AA and normal BM-MSCs was observed in affecting the production of interleukins (IL)-4, IL-10 and IL-17. Our data indicate that BM-MSCs were impaired in maintaining the immune homeostasis associated with CD4(+) T cells, which might aggravate the marrow failure in AA.

Cotransplantation of allogeneic mesenchymal and hematopoietic stem cells in children with aplastic anemia

We report here the preliminary results of allogeneic hematopoietic stem cell transplantation with mesenchymal stem cells (MSCs) for 6 cases of severe aplastic anemia. The patients ranged in age from 3 to 16 years, and the median time from diagnosis to transplantation was 32 months (range: 3-156 months). The conditioning regimens consisted of fludarabine, cyclophosphamide, and antithymocyte globulin with or without busulfan. Graft-versus-host disease (GvHD) was prevented by the administration of cyclosporine A, methotrexate, and mycophenolate mofetil, with or without anti-CD25 monoclonal antibody. The grafts were granulocyte colony-stimulating factor-mobilized bone marrow and peripheral blood from HLA antigen-haploidentical donors (3 cases) or peripheral blood only from unrelated HLA antigen-identical donors (3 cases). MSCs were intravenously injected at a median dose of 1.43 × 10(6)/kg (range: 0.85-2.5 × 10(6)/kg). The mean time for neutrophil and platelet recovery was 12.3 and 13.8 days, respectively. Acute GvHD grade I and II developed in 2 cases, and no chronic GvHD was documented. All patients were alive and transfusion independent at a median follow-up of 15 months (range: 6-29 months). Our report suggests that cotransplantation of allogeneic hematopoietic stem cells and MSCs might provide an opportunity for therapy for children with severe aplastic anemia.