A Refractory Celiac Patient Successfully Treated With Mesenchymal Stem Cell Infusions.

Type II refractory celiac disease (RCD), as defined according to the amount of aberrant intraepithelial lymphocytes, is a condition characterized by severe malabsorption syndrome and poor prognosis, with no effective treatment. Based on the regenerative and immunomodulatory properties of mesenchymal stem cells (MSCs), we investigated the feasibility, safety, and efficacy of serial infusions of autologous bone marrow-derived MSCs in a 51-year-old woman with type II RCD. Mesenchymal stem cells were isolated, expanded, and characterized following standard protocols. Monitoring of the patient's malabsorption indexes, mucosal architecture, and percentage of aberrant intraepithelial lymphocytes was scheduled for the time of enrollment, at each infusion, and after 6 months. Determination of mucosal expression of interleukin (IL)-15 and its receptor was also performed. Expansion of MSCs was feasible, and the patient underwent 4 systemic infusions of 2 × 10(6) MSCs/kg body weight 4 months apart, without adverse effects. During the treatment period, she experienced gradual and durable amelioration of her general condition, with normalization of stool frequency, body mass index, laboratory test results, and mucosal architecture. Remarkably, the expression of IL-15 and its receptor almost completely disappeared. Thus, treatment of RCD with serial MSC infusions seems promising, leading to recovery from the life-threatening condition while blocking the IL-15 pathogenic pathway.

Expression and function of toll-like receptors in human circulating endothelial colony forming cells.

Mature endothelial cells are known to sense microbial products through toll-like receptors (TLRs), a family of membrane proteins which serve as pathogen recognition and signaling elements; however, there are limited data in the literature about the expression and function of TLRs in human circulating endothelial colony forming cells (ECFCs), which are considered the most likely endothelial precursors. We expanded and differentiated in vitro umbilical cord blood (UCB) and adult peripheral blood (PB) ECFCs and studied the expression of TLR1 to TLR10 mRNA by qPCR analysis, and we further characterized TLR function in ECFCs through functional assays including in vitro ECFC growth and differentiation, assessment of cytokine production, and measurement of intracellular Ca(2+) signals. Both UCB- and PB-ECFCs had detectable mRNA levels of all the TLRs from 1 to 10; TLR4, a sensor of Gram-negative bacterial lipopolysaccharide (LPS), had a higher level compared to other TLRs. Exposure to LPS induced cytokine production, although with less efficiency compared to PB-mononuclear cells. However, no effect of LPS was seen on ECFC growth and differentiation, and no increase in intracellular Ca(2+) concentrations, which is essential for ECFC proliferation, was observed after exposure to increasing amounts of LPS. Our data show that all TLRs from 1 to 10 are constitutively expressed in ECFCs, and suggest that TLR4 is functional in ECFCs, but its activation through its ligand LPS does not affect ECFC growth and differentiation.

Mesenchymal stromal cells for cutaneous wound healing in a rabbit model: pre-clinical study applicable in the pediatric surgical setting.

OBJECTIVE: Mesenchymal stromal cells (MSCs) expanded in vitro have been proposed as a potential therapy for congenital or acquired skin defects in pediatrics. The aim of this pre-clinical study was to investigate the effects of intradermal injections of MSC in experimental cutaneous wound repair comparing allogeneic and autologous adipose stem cells (ASCs) and autologous bone marrow-mesenchymal stromal cells (BM-MSCs). METHODS: Mesenchymal stromal cells were in vitro expanded from adipose and BM tissues of young female New Zealand rabbits. MSCs were characterized for plastic adhesion, surface markers, proliferation and differentiation capacity. When an adequate number of cells (ASCs 10 × 10(6) and BM-MSCs 3 × 10(6), because of their low rate of proliferation) was reached, two skin wounds were surgically induced in each animal. The first was topically treated with cell infusions, the second was used as a control. The intradermal inoculation included autologous or allogeneic ASCs or autologous BM-MSCs. For histological examination, animals were sacrificed and wounds were harvested after 11 and 21 days of treatment. RESULTS: Rabbit ASCs were isolated and expanded in vitro with relative abundance, cells expressed typical surface markers (CD49e, CD90 and CD29). Topically, ASC inoculation provided more rapid wound healing than BM-MSCs and controls. Improved re-epithelization, reduced inflammatory infiltration and increased collagen deposition were observed in biopsies from wounds treated with ASCs, with the best result in the autologous setting. ASCs also improved restoration of skin architecture during wound healing. CONCLUSION: The use of ASCs may offer a promising solution to treat extended wounds. Pre-clinical studies are however necessary to validate the best skin regeneration technique, which could be used in pediatric surgical translational research.

Intracarotid Infusion of Mesenchymal Stem Cells in an Animal Model of Parkinson's Disease, Focusing on Cell Distribution and Neuroprotective and Behavioral Effects.

UNLABELLED: Mesenchymal stem cells (MSCs) have been proposed as a potential therapeutic tool for Parkinson's disease (PD) and systemic administration of these cells has been tested in preclinical and clinical studies. However, no information on survival and actual capacity of MSCs to reach the brain has been provided. In this study, we evaluated homing of intraarterially infused rat MSCs (rMSCs) in the brain of rats bearing a 6-hydroxydopamine (6-OHDA)-induced lesion of the nigrostriatal tract, to establish whether the toxin-induced damage is sufficient to grant MSC passage across the blood-brain barrier (BBB) or if a transient BBB disruption is necessary. The rMSC distribution in peripheral organs and the effects of cell infusion on neurodegenerative process and motor deficits were also investigated. rMSCs were infused 14 days after 6-OHDA injection. A hyperosmolar solution of mannitol was used to transiently permeabilize the BBB. Behavioral impairment was assessed by adjusting step test and response to apomorphine. Animals were sacrificed 7 and 28 days after cell infusion. Our work shows that appreciable delivery of rMSCs to the brain of 6-OHDA-lesioned animals can be obtained only after mannitol pretreatment. A notable percentage of infused cells accumulated in peripheral organs. Infusion of rMSCs did not modify the progression of 6-OHDA-induced damage or the motor impairment at the stepping test, but induced progressive normalization of the pathological response (contralateral turning) to apomorphine administration. These findings suggest that many aspects should be further investigated before considering any translation of MSC systemic administration into the clinical setting for PD treatment. SIGNIFICANCE: This study demonstrates that mesenchymal stem cells infused through the carotid artery do not efficiently cross the blood-brain barrier in rats with a Parkinson's disease-like degeneration of nigrostriatal neurons, unless a permeabilizing agent (e.g., mannitol) is used. The infusion did not reduce the neuronal damage and associated motor impairment, but abolished the motor abnormalities these animals typically show when challenged with a dopaminergic agonist. Therefore, although arterially infused mesenchymal stem cells did not show neurorestorative effects in this study's Parkinson's disease model, they appeared to normalize the pathological responsiveness of striatal neurons to dopaminergic stimulation. This capability should be further explored in future studies.

Persistent rhinovirus infection in pediatric hematopoietic stem cell transplant recipients with impaired cellular immunity.

BACKGROUND: HRV infections are generally self-limiting in healthy subjects, whereas in immunocompromised hosts HRV infections can lead to severe complications and persistent infections. The persistence of HRV shedding could be due to the inefficient immunological control of a single infectious episode. OBJECTIVES: To investigate the clinical, virologic and immunologic characteristics of pediatric HSCT recipients with HRV-PI infection. STUDY DESIGN: During the period 2006-2012, eight hematopoietic stem cell transplant (HSCT) recipients presented with persistent rhinovirus infection (HRV-PI, ≥30 days). Viral load and T-CD4(+), T-CD8(+), B and NK lymphocyte counts at the onset of infection were compared with those of fourteen HSCT recipients with acute HRV infection (HRV-AI, ≤15 days). RESULTS: The median duration of HRV positivity in patients with HRV-PI was 61 days (range 30-174 days) and phylogenetic analysis showed the persistence of a single HRV type in all patients (100%). In HSCT recipients with HRV-PI, T-CD4(+), T-CD8(+) and NK cell counts at the onset of infection were significantly lower than those observed in recipients with HRV-AI (p<0.01), while B cell counts were similar in the two groups (p= 0.25). A decrease in HRV load was associated with a significant increase in T-CD4(+), T-CD8(+)and NK lymphocyte counts in HRV-PI patients (p<0.01). CONCLUSIONS: This study suggests a role for cellular immunity in HRV clearance and highlights the importance of its recovery for the control of HRV infection in HSCT recipients.

Comprehensive characterization of mesenchymal stromal cells from patients with Fanconi anaemia.

Fanconi anaemia (FA) is an inherited disorder characterized by pancytopenia, congenital malformations and a predisposition to develop malignancies. Alterations in the haematopoietic microenvironment of FA patients have been reported, but little is known regarding the components of their bone marrow (BM) stroma. We characterized mesenchymal stromal cells (MSCs) isolated from BM of 18 FA patients both before and after allogeneic haematopoietic stem cell transplantation (HSCT). Morphology, fibroblast colony-forming unit (CFU-F) ability, proliferative capacity, immunophenotype, differentiation potential, ability to support long-term haematopoiesis and immunomodulatory properties of FA-MSCs were analysed and compared with those of MSCs expanded from 15 age-matched healthy donors (HD-MSCs). FA-MSCs were genetically characterized through conventional karyotyping, diepoxybutane-test and array-comparative genomic hybridization. FA-MSCs generated before and after HSCT were compared. Morphology, immunophenotype, differentiation potential, ability in vitro to inhibit mitogen-induced T-cell proliferation and to support long-term haematopoiesis did not differ between FA-MSCs and HD-MSCs. CFU-F ability and proliferative capacity of FA-MSCs isolated after HSCT were significantly lower than those of HD-MSCs. FA-MSCs reached senescence significantly earlier than HD-MSCs and showed spontaneous chromosome fragility. Our findings indicate that FA-MSCs are defective in their ability to survive in vitro and display spontaneous chromosome breakages; whether these defects are involved in pathophysiology of BM failure syndromes deserves further investigation.

Possible alternatives to antimicrobial therapies.

The care of immunosuppressed patients has constantly improved over the years, and pharmacologic developments contributed significantly to this success. However, despite these advances, current anti-infectious agents are limited in their efficacy by either weak specificity or side effects, including suppression of bone marrow function. Control of infection will ultimately depend on reconstitution of specific immunity. Thus, adoptive cellular immunotherapy represents an attractive, low-toxicity strategy to restore specific immune surveillance, and prevent/treat potentially life-threatening disease due to pathogens relevant to the immunosuppressed host. Evidence derived from trials conducted in recipients of hematopoietic stem cell transplantation indicate that adoptive transfer of antigen-specific T cells is a feasible and safe strategy to restore protective immunity and prevent or reverse virus-associated disease. Despite the great potential, immunotherapy for viral and fungal disease still has a marginal role in the management of immunosuppressed patients. This is due to limitations inherent to the technologies and products employed, and, more importantly, to the financial and structural requirements that are associated with GMP production. However, cell therapy offers a unique opportunity to restore antipathogen immune surveillance, and it is therefore conceivable that application of this strategy will increase in the next few years.

In vitro biosafety profile evaluation of multipotent mesenchymal stem cells derived from the bone marrow of sarcoma patients.

BACKGROUND: In osteosarcoma (OS) and most Ewing sarcoma (EWS) patients, the primary tumor originates in the bone. Although tumor resection surgery is commonly used to treat these diseases, it frequently leaves massive bone defects that are particularly difficult to be treated. Due to the therapeutic potential of mesenchymal stem cells (MSCs), OS and EWS patients could benefit from an autologous MSCs-based bone reconstruction. However, safety concerns regarding the in vitro expansion of bone marrow-derived MSCs have been raised. To investigate the possible oncogenic potential of MSCs from OS or EWS patients (MSC-SAR) after expansion, this study focused on a biosafety assessment of MSC-SAR obtained after short- and long-term cultivation compared with MSCs from healthy donors (MSC-CTRL). METHODS: We initially characterized the morphology, immunophenotype, and differentiation multipotency of isolated MSC-SAR. MSC-SAR and MSC-CTRL were subsequently expanded under identical culture conditions. Cells at the early (P3/P4) and late (P10) passages were collected for the in vitro analyses including: sequencing of genes frequently mutated in OS and EWS, evaluation of telomerase activity, assessment of the gene expression profile and activity of major cancer pathways, cytogenetic analysis on synchronous MSCs, and molecular karyotyping using a comparative genomic hybridization (CGH) array. RESULTS: MSC-SAR displayed comparable morphology, immunophenotype, proliferation rate, differentiation potential, and telomerase activity to MSC-CTRL. Both cell types displayed signs of senescence in the late stages of culture with no relevant changes in cancer gene expression. However, cytogenetic analysis detected chromosomal anomalies in the early and late stages of MSC-SAR and MSC-CTRL after culture. CONCLUSIONS: Our results demonstrated that the in vitro expansion of MSCs does not influence or favor malignant transformation since MSC-SAR were not more prone than MSC-CTRL to deleterious changes during culture. However, the presence of chromosomal aberrations supports rigorous phenotypic, functional and genetic evaluation of the biosafety of MSCs, which is important for clinical applications.

Genomic alterations in human umbilical cord-derived mesenchymal stromal cells call for stringent quality control before any possible therapeutic approach.

BACKGROUND AIMS: The umbilical cord (UC) is a promising source of mesenchymal stromal cells (MSCs). UC-MSCs display very similar in vitro characteristics to bone marrow-MSCs and could represent a valuable alternative for cell-based therapies. However, it is still unclear whether UC-MSCs are prone or not to the acquisition of genomic imbalances during in vitro expansion. METHODS: With the use of array-comparative genomic hybridization, we compared copy number variations of early (P2-P3) and late (>P5) passages of in vitro-expanded UC-MSCs. RESULTS: In two of 11 long-term UC-MSCs cultures, we observed the appearance of clones carrying genomic imbalances, which generated genetic mosaicism at intermediate passages. Although still able to reach the senescence phase, the cells carrying the genomic imbalance acquired a proliferative advantage, as demonstrated by the increase in frequency during long-term culture. CONCLUSIONS: Altogether, our results suggest that UC-MSC-based clinical protocols should be designed with caution; their clinical use should be preceded by array-comparative genomic hybridization screening for the acquisition of genomic imbalances during in vitro expansion.

Antineutrophil cytoplasmic antibody-associated renal vasculitis treated with autologous mesenchymal stromal cells: evaluation of the contribution of immune-mediated mechanisms.

We report the first case of renal antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis treated with autologous mesenchymal stromal cells (MSCs). A 73-year-old man was admitted to the hospital for malaise, weight loss, and oliguria. His serum creatinine level was 2.7 mg/dL but it rapidly increased to 7.8 mg/dL; urinalysis showed proteinuria and hematuria, and the ANCA to myeloperoxidase with a perinuclear pattern (pANCA) titer was high (132 IU/mL). Renal biopsy showed necrotizing crescentic glomerulonephritis. Standard immunosuppressive therapy (cyclophosphamide and corticosteroids) was ineffective. Rituximab therapy was started, but it was discontinued after the third dose to minimize the risk of systemic spread of a severe oral Candida infection and to prevent superinfections that were facilitated by leukopenia. The patient received autologous MSCs, 1.5 × 10(6) cells/kg body weight, intravenously. After 7 days, his serum creatinine level decreased to 2.2 mg/dL, pANCA titer decreased to 75 IU/mL, and urinalysis findings normalized. Eight months later, he received a second MSC infusion because his serum creatinine level increased. In 1 week, his creatinine level decreased to 1.9 mg/dL and his pANCA titer decreased to 14 IU/mL. Immunosuppressive therapy was subsequently withdrawn. At the last follow-up visit, 12 months after the second MSC infusion, the patient remained in clinical remission without any therapy. Infusion of MSCs induced expansion of the T-lymphocyte subset expressing a regulatory T-cell phenotype (CD4(+)CD25(+)Foxp3(+)) and a notable reduction in interferon-γ, interleukin 6, and tumor necrosis factor serum levels.

Mesenchymal stem/stromal cells: a new ''cells as drugs'' paradigm. Efficacy and critical aspects in cell therapy.

Mesenchymal stem cells (MSCs) were first isolated more than 50 years ago from the bone marrow. Currently MSCs may also be isolated from several alternative sources and they have been used in more than a hundred clinical trials worldwide to treat a wide variety of diseases. The MSCs mechanism of action is undefined and currently under investigation. For in vivo purposes MSCs must be produced in compliance with good manufacturing practices and this has stimulated research on MSCs characterization and safety. The objective of this review is to describe recent developments regarding MSCs properties, physiological effects, delivery, clinical applications and possible side effects.

Case report: long-lasting response in a patient with metastatic renal cell cancer receiving antitumor cytotoxic T lymphocytes.

AIMS AND BACKGROUND: Adoptive immunotherapy can be a therapeutic option to treat cancer patients with advanced-stage disease refractory to conventional therapies. METHODS AND STUDY DESIGN: We used T-cell therapy with autologous antitumor cytotoxic T lymphocytes (CTLs) in a patient with metastatic renal cell carcinoma. Autologous antitumor CTLs obtained by stimulating CD8-enriched cells with dendritic cells pulsed with irradiated apoptotic tumor cells and expanded in vitro were transfused on days +14 and +28 following chemotherapy and every 2 to 4 months thereafter. RESULTS AND CONCLUSIONS: Treatment with high doses of antitumor CTLs proved to be safe and induced immunological responses and long-lasting clinical benefit in our patient.

In vitro evaluation of graft-versus-graft alloreactivity as a tool to identify the predominant cord blood unit before double cord blood transplantation.

The transplantation of two cord blood (CB) units obtained from unrelated donors (double CBT) is an effective strategy for adult patients with hematologic malignancies. Sustained hematopoiesis after double CBT is usually derived from a single donor, and only a few transplantation recipients displaying a stable mixed donor-donor chimerism have been reported. We investigated the mechanisms underlying single-donor predominance in double CBT by studying in vitro the role of the graft-versus-graft cell-mediated immune effect in two-way mixed-lymphocyte culture, along with the contribution of differential hematopoietic progenitor (HP) potency in HP mixed cultures. Results for the two-way mixed-lymphocyte culture showed that despite the weak and variable alloantigen-specific cytotoxic potential displayed by CB mononuclear cells, an immune-mediated dominance for one of the two CB units was detected in the majority of experiments. Alloantigen-induced cytotoxic activity was directed toward both CB-HP and phytohemagglutinin (PHA)-activated T lymphoblastoid cells. The CB unit with the higher fold expansion of CD34(+) cells in single-expansion culture was prevalent in the HP mixed-expansion culture, as shown by DNA chimerism evaluation. Based on these data, we hypothesize that the dominant CB unit is able to develop prevalent cytotoxic activity toward activated lymphocytes of the other CB unit, thereby preventing them from exerting alloantigen-specific cytotoxic potential against both activated lymphocytes and HPs of the dominant unit. In accordance with this hypothesis, we propose the evaluation of alloantigen-induced cytotoxic activity generated in two-way mixed-lymphocyte culture and directed toward PHA-activated T lymphoblastoid cells as a tool to identify the potentially predominant CB unit before double CBT.

Feasibility and safety of adoptive immunotherapy with ex vivo-generated autologous, cytotoxic T lymphocytes in patients with solid tumor.

BACKGROUND AIMS: Adoptive T-cell therapy with tumor-specific T cells has emerged as a potentially useful approach for treating patients with advanced malignancies. We have demonstrated previously the feasibility of obtaining large numbers of autologous anti-tumor-specific cytotoxic T lymphocytes (CTL) generated by stimulation of patients' peripheral blood mononuclear cells with dendritic cells pulsed with apoptotic tumor cells. Methods. Six patients with progressing metastatic solid tumors (one renal cell carcinoma, two ovarian cancers, two extraosseous peripheral neuroectodermal tumors, one soft tissue sarcoma) not eligible for conventional therapies were treated with adoptive immunotherapy. Anti-tumor CTL, proven to be reactive in vitro against patient tumor cells, but not against normal cells, were infused following lymphodepleting chemotherapy administered to favor T-cell proliferation in vivo. RESULTS: Patients received a median of nine CTL infusions (range 2-19). The median number of CTL administered per infusion was 11 × 10(8) (range 1-55 × 10(8)). No patient experienced acute or late adverse events related to CTL infusion, even when large numbers of cells were given. Post-infusion laboratory investigations demonstrated an increase in the frequency of circulating anti-tumor T-cells and, in patients with a longer follow-up receiving two CTL infusions/year, a stabilization of these values. CONCLUSIONS: Our study demonstrates that autologous ex vivo-generated anti-tumor CTL can be administered safely in patients with advanced solid tumors and can improve the immunologic reactivity of recipients against tumor. These preliminary results provide a rationale for evaluating the clinical efficacy of this immunotherapeutic approach in phase I/II studies.

Cell-cycle phases and genetic profile of bone marrow-derived mesenchymal stromal cells expanded in vitro from healthy donors.

Human mesenchymal stromal cells (MSCs) expanded in vitro for cell therapy approaches need to be carefully investigated for genetic stability, by employing both molecular and conventional karyotyping. Reliability of cytogenetic analysis may be hampered in some MSC samples by the difficulty of obtaining an adequate number of metaphases. In an attempt to overcome this problem, a methodology apt to evaluate the cell-cycle structure on synchronous MSCs was optimised. Results obtained in five independent experiments by comparing cell-cycle analysis of synchronous and asynchronous MSC populations evaluated at early and late culture passages documented that in synchronous MSCs, 30% of cells entered G2/M phase after about 27-28 h of culture, while in asynchronous MSCs only 8% of cells in G2/M phase could be observed at the same time point. Cytogenetic analysis on synchronous MSCs allowed us to obtain 20-25 valuable metaphases/slide, whereas only 0-4 metaphases/slide were detectable in asynchronous preparations.

Invariant NKT cell reconstitution in pediatric leukemia patients given HLA-haploidentical stem cell transplantation defines distinct CD4+ and CD4- subset dynamics and correlates with remission state.

Immune reconstitution plays a crucial role on the outcome of patients given T cell-depleted HLA-haploidentical hematopoietic stem cell transplantation (hHSCT) for hematological malignancies. CD1d-restricted invariant NKT (iNKT) cells are innate-like, lipid-reactive T lymphocytes controlling infections, cancer, and autoimmunity. Adult mature iNKT cells are divided in two functionally distinct CD4(+) and CD4(-) subsets that express the NK receptor CD161 and derive from thymic CD4(+)CD161(-) precursors. We investigated iNKT cell reconstitution dynamics in 33 pediatric patients given hHSCT for hematological malignancies, with a follow-up reaching 6 y posttransplantation, and correlated their emergence with disease relapse. iNKT cells fully reconstitute and rapidly convert into IFN-γ-expressing effectors in the 25 patients maintaining remission. CD4(+) cells emerge earlier than the CD4(-) ones, both displaying CD161(-) immature phenotypes. CD4(-) cells expand more slowly than CD4(+) cells, though they mature with significantly faster kinetics, reaching full maturation by 18 mo post-hHSCT. Between 4 and 6 y post-hHSCT, mature CD4(-) iNKT cells undergo a substantial expansion burst, resulting in a CD4(+)

Autologous bone marrow-derived mesenchymal stromal cells in the treatment of fistulising Crohn's disease.

OBJECTIVE: External fistulas represent a disabling manifestation of Crohn's disease with a difficult curability and a high relapse rate despite a large therapeutic armamentarium. Stem cell therapy is a novel and promising approach for treatment of chronic inflammatory conditions. We therefore investigated the feasibility, safety and efficacy of serial intrafistular injections of autologous bone marrow-derived mesenchymal stromal cells (MSCs) in the treatment of fistulising Crohn's disease. PATIENTS AND METHODS: We enrolled 12 consecutive outpatients (eight males, median age 32 years) refractory to or unsuitable for current available therapies. MSCs were isolated from bone marrow and expanded ex vivo to be used for both therapeutic and experimental purposes. Ten patients (two refused) received intrafistular MSC injections (median 4) scheduled every 4 weeks, and were monitored by surgical, MRI and endoscopic evaluation for 12 months afterwards. The feasibility of obtaining at least 50×106 MSCs from each patient, the appearance of adverse events, and the efficacy in terms of fistula healing and reduction of both Crohn's disease and perianal disease activity indexes were evaluated. In addition, the percentage of both mucosal and circulating regulatory T cells expressing FoxP3, and the ability of MSCs to influence mucosal T cell apoptosis were investigated. RESULTS: MSC expansion was successful in all cases; sustained complete closure (seven cases) or incomplete closure (three cases) of fistula tracks with a parallel reduction of Crohn's disease and perianal disease activity indexes (p < 0.01 for both), and rectal mucosal healing were induced by treatment without any adverse effects. The percentage of mucosal and circulating regulatory T cells significantly increased during the treatment and remained stable until the end of follow up (p < 0.0001 and p < 0.01, respectively). Furthermore, MSCs have been proven to affect mucosal T cell apoptotic rate. CONCLUSIONS: Locally injected MSCs represent a feasible, safe and beneficial therapy in refractory fistulising Crohn's disease.

Immunotherapy against EBV-lymphoma in recipients of HSCT.

Epstein-Barr virus (EBV)-associated lymphoproliferations represent life-threatening complications of hematopoietic stem cell transplantation. In the last decade, immunological therapeutic strategies that allow us to selectively abrogate the origin of lymphoproliferation, namely B-cell compartment or EBV antigen-expressing tumor cells, have significantly reduced treatment-related toxicity while maintaining equal or superior efficacy. A further implementation is the possibility of preventing disease occurrence by delivering immunotherapy in the presymptomatic phase, on the basis of EBV-DNA blood levels. Despite the excellent results, T-cell therapy with EBV-specific cytotoxic T-lymphocytes has but a marginal role in the treatment of these forms. Promising implementations are underway, including logistic solutions to extend T-cell therapy beyond academic centers, delineation of strategies aimed at simplifying/shortening production and targeting immune evasion mechanisms exerted by tumor cells.