[Recent advances in prevention and treatment of chronic graft-versus-host disease after allogeneic hematopoietic stem cell transplantation].

Chronic graft-versus-host disease (cGVHD) negatively impacts long-term survival and quality of life (QOL) after allogeneic hematopoietic cell transplantation. Corticosteroids are the first-line treatment for cGVHD, but approximately 30% to 70% of patients develop steroid-refractory cGVHD (SR-cGVHD), which has an extremely poor prognosis. The pathophysiology of cGVHD is more complicated than acute GVHD, but recent advances using murine models in conjunction with human studies indicate three major phases: 1) acute inflammation, 2) chronic inflammation with loss of immune tolerance, and 3) disrupted target organ homeostasis and fibrosis. Strategies that help prevent cGVHD include optimal donor selection and choice of conditioning regimen as well as pharmacologic and graft manipulation strategies. The key cellular mediators of SR-cGVHD are T cells, B cells, antigen-presenting cells, and fibroblasts. T cells and B cells are now targetable with the inhibitors ibrutinib and ruxolitinib, respectively. Recently, promising results have been obtained by modulating pathologic T cell responses with Rock2 inhibitors and targeting fibrosis with CSF-1R inhibitors. To optimize the use of these medications, a better understanding of the biological and target organ-specific mechanisms of cGVHD is needed. Here we review recent advances in cGVHD pathogenesis and discuss how best to implement recently approved biology-driven treatments for cGVHD.

Transplantation of Donor-Recipient Chimeric Cells Restores Peripheral Blood Cell Populations and Increases Survival after Total Body Irradiation-Induced Injury in a Rat Experimental Model.

Current therapies for acute radiation syndrome (ARS) involve bone marrow transplantation (BMT), leading to graft-versus-host disease (GvHD). To address this challenge, we have developed a novel donor-recipient chimeric cell (DRCC) therapy to increase survival and prevent GvHD following total body irradiation (TBI)-induced hematopoietic injury without the need for immunosuppression. In this study, 20 Lewis rats were exposed to 7 Gy TBI to induce ARS, and we assessed the efficacy of various cellular therapies following systemic intraosseous administration. Twenty Lewis rats were randomly divided into four experimental groups (n = 5/group): saline control, allogeneic bone marrow transplantation (alloBMT), DRCC, and alloBMT + DRCC. DRCC were created by polyethylene glycol-mediated fusion of bone marrow cells from 24 ACI (RT1a) and 24 Lewis (RT11) rat donors. Fusion feasibility was confirmed by flow cytometry and confocal microscopy. The impact of different therapies on post-irradiation peripheral blood cell recovery was evaluated through complete blood count, while GvHD signs were monitored clinically and histopathologically. The chimeric state of DRCC was confirmed. Post-alloBMT mortality was 60%, whereas DRCC and alloBMT + DRCC therapies achieved 100% survival. DRCC therapy also led to the highest white blood cell counts and minimal GvHD changes in kidney and skin samples, in contrast to alloBMT treatment. In this study, transplantation of DRCC promoted the recovery of peripheral blood cell populations after TBI without the development of GVHD. This study introduces a novel and promising DRCC-based bridging therapy for treating ARS and extending survival without GvHD.

[Advances in nutritional support for children undergoing hematopoietic stem cell transplantation]. / é€ è¡€å¹²ç»†èƒžç§»æ¤å„¿ç«¥çš„è¥å »æ”¯æŒè¿›å±•.

Hematopoietic stem cell transplantation (HSCT) is a therapeutic option for various potentially life-threatening malignant and non-malignant diseases in children, such as malignancies, immunodeficiency syndromes, severe aplastic anemia, and inherited metabolic disorders. During transplantation, many factors can affect the nutritional status of the children, including radiotherapy, chemotherapy, gastrointestinal disorders, graft-versus-host disease, and medications. Malnutrition has been associated with decreased overall survival and increased complications in children undergoing HSCT, making nutritional support a crucial component of their management. However, currently, there is a lack of guidelines or consensus on nutritional support for children undergoing HSCT in China. Therefore, this review summarizes the progress in nutritional support for children undergoing HSCT, aiming to provide clinical guidance.

The road to refractory graft-versus-host disease is paved with good intentions.

Refractory acute graft-versus-host disease (GVHD) occurs when the immune injury exceeds the capacity of injured tissues to regenerate and repair. While glucocorticoids have been used for decades to treat GVHD, Arnhold, Chang, and colleagues in this issue of the JCI question whether this approach can in fact be counterproductive. Using in vivo experimental models of GVHD and in vitro intestinal organoids, the study authors show that glucocorticoid exposure directly impeded small intestinal epithelial proliferation and survival, thus preventing the resolution of injury. These findings suggest that future treatment approaches for acute GVHD should include measures to reduce immune reactivity as well as interventions to actively promote tissue resilience.

Mesenchymal stromal/stem cells promote intestinal epithelium regeneration after chemotherapy-induced damage.

BACKGROUND: Allogeneic hematopoietic stem cell transplantation (HSCT) is a curative treatment for leukemia and a range of non-malignant disorders. The success of the therapy is hampered by occurrence of acute graft-versus-host disease (aGvHD); an inflammatory response damaging recipient organs, with gut, liver, and skin being the most susceptible. Intestinal GvHD injury is often a life-threatening complication in patients unresponsive to steroid treatment. Allogeneic mesenchymal stromal/stem cell (MSC) infusions are a promising potential treatment for steroid-resistant aGvHD. Data from our institution and others demonstrate rescue of approximately 40-50% of aGvHD patients with MSCs in Phase I, II studies and minor side effects. Although promising, better understanding of MSC mode of action and patient response to MSC-based therapy is essential to improve this lifesaving treatment. METHODS: Single cell human small intestine organoids were embedded in Matrigel, grown for 5 days and treated with busulfan for 48 h. Organoids damaged by treatment with busulfan or control organoids were co-cultured with 5000, 10,000, and 50,000 MSCs for 24 h, 48 h or 7 days and the analyses such as surface area determination, proliferation and apoptosis assessment, RNA sequencing and proteomics were performed. RESULTS: Here, we developed a 3D co-culture model of human small intestinal organoids and MSCs, which allows to study the regenerative effects of MSCs on intestinal epithelium in a more physiologically relevant setting than existing in vitro systems. Using this model we mimicked chemotherapy-mediated damage of the intestinal epithelium. The treatment with busulfan, the chemotherapeutic commonly used as conditioning regiment before the HSCT, affected pathways regulating epithelial to mesenchymal transition, proliferation, and apoptosis in small intestinal organoids, as shown by transcriptomic and proteomic analysis. The co-culture of busulfan-treated intestinal organoids with MSCs reversed the effects of busulfan on the transcriptome and proteome of intestinal epithelium, which we also confirmed by functional evaluation of proliferation and apoptosis. CONCLUSIONS: Collectively, we demonstrate that our in vitro co-culture system is a new valuable tool to facilitate the investigation of the molecular mechanisms behind the therapeutic effects of MSCs on damaged intestinal epithelium. This could benefit further optimization of the use of MSCs in HSCT patients.

[Pathogenesis and Therapeutic Prospects of Chronic Graft-Versus-Host Disease --Review].

Chronic graft-versus-host disease (cGVHD) is one of a major complication that affecting the long-term survival and living quality of patients after allogeneic hematopoietic stem cell transplantation, with the incidence of 30%-70%. Unlike acute GVHD, cGVHD involves a large number of immune cells and cytokines in addition to T cell, which is activated abnormally by the donor, and cytokine storms, which characterized by infiltration of donor lymphocytes and damage to host target organ. Recent studies have further made progress in targeting related immune cells and cytokines. In this review, the pathogenesis and therapeutic prospects of cGVHD were summarized from the perspectives of classical innate and adaptive immunity.

The Confounding Role of Graft-Versus-Host Disease in Animal Models of Cancer Immunotherapy: A Systematic Review.

BACKGROUND: Cancer immunotherapy has emerged as a transformative approach for treating various malignancies, including melanoma, lung cancer, breast cancer, and leukemia. Animal models have been instrumental in elucidating the mechanisms and potential of these therapies. However, graft-versus-host disease (GVHD) is an inherent challenge in these studies, primarily because the introduction of foreign immune cells or tissues often triggers immune responses. METHODS: A detailed systematic search was conducted across various scientific databases, including PubMed, Scopus, Embase, and Web of Science. The search aimed to identify peer-reviewed articles published in English from January 2000 to September 2023. Keywords and phrases used in the search included "Graft-versus-Host Disease", "GVHD", "animal models", "cancer immunotherapy", and combinations thereof. Boolean operators (AND/OR) were employed to refine the search. Finally, 6 articles were included in this systematic review, which is registered on PROSPERO (ID number CRD42024488544). RESULTS: Our systematic review identified several mechanisms employed in animal studies to mitigate the confounding effects of GVHD. These included genetically modified mouse models, immunosuppressive drugs, and humanized mice. Furthermore, the review highlights innovative approaches such as selective T-cell depletion and the use of specific cytokine inhibitors. CONCLUSION: By systematically identifying and mitigating the confounding effects of GVHD, we can significantly improve the predictive validity of preclinical trials, obtain broadly applicable findings, improve the efficiency of drugs, enhance safety profiling, and develop better therapeutic strategies. This approach is crucial in ensuring that the immunotherapeutic strategies developed in the laboratory are reflective of the human physiological response, thereby bridging a critical translational gap in oncological research.

TCRαß-depleted hematopoietic stem cell transplant and third-party CD45RA+ depleted adoptive cell therapy for treatment of post-transplant parvovirus B19 aplastic crisis.

This is a case report of a 6-year-old girl with relapsed B cell acute lymphoblastic leukemia in which adoptive cell therapy was applied successfully to treat refractory human parvovirus (HPV) B19 infection. Allogenic chimeric antigen receptor (CAR) T-cell therapy (bispecific CD19/CD22) was bridged to hematopoietic stem cell transplantation (HSCT) using a haploidentical paternal donor. However, HPV B19 DNAemia progressed and transfusion-related graft versus host disease occurred. After finding a third-party related donor with a better HLA match, haploidentical HPV B19-seropositive CD45RA+ depleted cells (16.5 × 106/kg) were administered and paternal TCRαß+ depleted stem cell were retransplanted. The HPV B19 DNAemia became negative within 1 week and the reticulocyte, neutrophil, hemoglobin, and platelet counts gradually normalized. The patient remained stable during the 1-year outpatient follow-up period. Thus, our case report highlights that persistent B19 infection can lead to pancytopenia, aplastic crisis, and graft rejection and TCRαß+ depleted haplo-HSCT is an effective means of hematopoiesis recovery. CD45RO memory T-cell therapy is the key to treating and preventing the development of refractory severe HPV B19 infection.

Lipocalin-2: a novel potential therapy for GVHD.

Czech et al. used mouse models of allogeneic hematopoietic stem cell transplantation (allo-HCT) to investigate the role of lipocalin-2 (LCN2) as a newfound regulator of intestinal graft-versus-host disease (GVHD). Administration of recombinant LCN2 protein after disease onset prevented GVHD progression, suggesting that it may play a role in reversing tissue damage that has already begun.

Third-party fecal microbiota transplantation for high-risk treatment-naïve acute GVHD of the lower GI tract.

ABSTRACT: Disruption of the intestinal microbiome is observed with acute graft-versus-host disease (GVHD) of the lower gastrointestinal (LGI) tract, and fecal microbiota transplantation (FMT) has successfully cured steroid-refractory cases. In this open-label, single-arm, pilot study, third-party, single-donor FMT was administered in combination with systemic corticosteroids to participants with high-risk acute LGI GVHD, with a focus on treatment-naïve cases. Participants were scheduled to receive 1 induction dose (15 capsules per day for 2 consecutive days), followed by 3 weekly maintenance doses, consisting of 15 capsules per dose. The primary end point of the study was feasibility, which would be achieved if ≥80% of participants able to swallow ≥40 of the 75 scheduled capsules. Ten participants (9 treatment-naïve; 1 steroid-refractory) were enrolled and treated. The study met the primary end point, with 9 of 10 participants completing all eligible doses. Organ-specific LGI complete response rate at day 28 was 70%. Initial clinical response was observed within 1 week for all responders, and clinical responses were durable without recurrent LGI GVHD in complete responders. Exploratory analyses suggest that alpha diversity increased after FMT. Although recipient microbiome composition never achieved a high degree of donor similarity, expansion of donor-derived species and increases in tryptophan metabolites and short-chain fatty acids were observed within the first 7 days after FMT. Investigation into the use of microbiome-targeted interventions earlier in the treatment paradigm for acute LGI GVHD is warranted. This trial was registered at www.ClinicalTrials.gov as #NCT04139577.

"Window of Opportunity" in Ocular Graft-Versus-Host Disease Treatment: Results of a Longitudinal Study and Case Reports.

OBJECTIVE: To perform a longitudinal study for determining the development of ocular graft-versus-host disease (oGVHD) after allogeneic hematopoietic stem cell transplant (HSCT) and report cases that illustrate the "window of opportunity" concept in oGVHD treatment. METHODS: Patients (n=61) were examined at prescheduled clinic visits before HSCT and three-month intervals after HSCT for 2 years. The presence or absence of oGVHD was determined using the international chronic oGVHD consensus group diagnostic criteria. Ocular surface washings (OSW) were obtained at each visit and analyzed for cytokine levels. RESULTS: In the longitudinal study, 26.2% (n=16; progressed group) developed either probable (11.5%, n=7) or definite oGVHD (14.8%, n=9). In the progressed group, clinically significant changes in signs (corneal staining and Schirmer I test) and symptoms at the post-HSCT visit as compared with the pre-HSCT visit occurred at 9 months. Significant differences in clinical signs and symptoms (whether average post-HSCT values or changes in values over pre-HSCT levels) between the progressed and nonprogressed groups occurred at a 9-month visit or later. In the progressed group, 55.6% of eyes that had negative matrix metalloproteinase 9 (MMP-9) test at pre-HSCT turned MMP-9 positive at 3 to 6 months post-HSCT. In the progressed group, interleukin 8 levels in OSW were significantly increased at 6 months post-HSCT. In the case reports, the "window of opportunity" was detected by MMP-9 turning positive, early corneal staining, interleukin 8 increase in OSW, and peripheral corneal epithelial thinning, which resolved with treatment initiation. CONCLUSIONS: A "window of opportunity" exists before patients developing symptomatic tear-deficient dry eye after HSCT for initiating treatment that may preempt oGVHD development; however, larger-scale longitudinal studies are needed for definitive recommendations.

ERS/EBMT clinical practice guidelines on treatment of pulmonary chronic graft-versus-host disease in adults.

Chronic graft-versus-host disease (cGvHD) is a common complication after allogeneic haematopoietic stem cell transplantation, characterised by a broad disease spectrum that can affect virtually any organ. Although pulmonary cGvHD is a less common manifestation, it is of great concern due to its severity and poor prognosis. Optimal management of patients with pulmonary cGvHD is complicated and no standardised approach is available. The purpose of this joint European Respiratory Society (ERS) and European Society for Blood and Marrow Transplantation task force was to develop evidence-based recommendations regarding the treatment of pulmonary cGvHD phenotype bronchiolitis obliterans syndrome in adults. A multidisciplinary group representing specialists in haematology, respiratory medicine and methodology, as well as patient advocates, formulated eight PICO (patient, intervention, comparison, outcome) and two narrative questions. Following the ERS standardised methodology, we conducted systematic reviews to address these questions and used the Grading of Recommendations Assessment, Development and Evaluation approach to develop recommendations. The resulting guideline addresses common therapeutic options (inhalation therapy, fluticasone-azithromycin-montelukast, imatinib, ibrutinib, ruxolitinib, belumosudil, extracorporeal photopheresis and lung transplantation), as well as other aspects of general management, such as lung functional and radiological follow-up and pulmonary rehabilitation, for adults with pulmonary cGvHD phenotype bronchiolitis obliterans syndrome. These recommendations include important advancements that could be incorporated in the management of adults with pulmonary cGvHD, primarily aimed at improving and standardising treatment and improving outcomes.

Blood and guts: how the intestinal microbiome shapes hematopoiesis and treatment of hematologic disease.

ABSTRACT: Over the past 10 years, there has been a marked increase in recognition of the interplay between the intestinal microbiome and the hematopoietic system. Despite their apparent distance in the body, a large literature now supports the relevance of the normal intestinal microbiota to steady-state blood production, affecting both hematopoietic stem and progenitor cells as well as differentiated immune cells. Microbial metabolites enter the circulation where they can trigger cytokine signaling that influences hematopoiesis. Furthermore, the state of the microbiome is now recognized to affect outcomes from hematopoietic stem cell transplant, immunotherapy, and cellular therapies for hematologic malignancies. Here we review the mechanisms by which microbiotas influence hematopoiesis in development and adulthood as well as the avenues by which microbiotas are thought to impact stem cell transplant engraftment, graft-versus-host disease, and efficacy of cell and immunotherapies. We highlight areas of future research that may lead to reduced adverse effects of antibiotic use and improved outcomes for patients with hematologic conditions.

Extracorporeal photopheresis as a promising strategy for the treatment of graft-versus-host disease after CAR T-cell therapy.

ABSTRACT: Graft-versus-host disease (GVHD) occurs in about 10% to 33% of patients receiving "allogeneic" or "autologous" chimeric antigen receptor T (CAR-T) cells after preceding allogeneic hematopoietic stem cell transplantation (allo-HSCT) due to the substantial presence of alloreactive T cells. Extracorporeal photopheresis (ECP) shows promising clinical outcomes in the treatment of GVHD after allo-HSCT without hampering antitumor and antiviral effects. This raises an interesting question: whether ECP might constitute a new way to treat patients with GVHD after CAR T-cell therapy without compromising CAR-T cells significantly. Third-generation CD19-specific CAR-T cells were generated and an in vitro ECP protocol was established. The impact of ECP on CAR-T cells was comprehensively investigated in 2 models: the nondilution model reflects days after CAR T-cell infusion and the dilution model weeks after infusion. The therapeutic effect of ECP on GVHD was examined in an in vitro mixed lymphocyte reaction (MLR) assay. We found, ECP-treated CAR-T cells demonstrated reduced potency in inducing alloreaction compared with that of the group without ECP treatment in MLR assay. ECP could selectively induce apoptosis, thereby enriching the naive and central memory CAR-T cells with a reduced alloreactivity. The cytokine milieu of CAR-T cells could be switched from immune stimulation to immune tolerance in both models. Moreover, ECP could modulate the proliferative capacity of CAR-T cells without hampering their long-term functionality in the dilution model. In conclusion, ECP constitutes a promising treatment strategy for GVHD after allo-HSCT and CAR T-cell transfusion, as ECP reduces the alloreactivity without hampering CAR T-cell functionality.

Source of hematopoietic progenitor cells determines their capacity to generate innate lymphoid cells ex vivo.

BACKGROUND AIMS: The success of allogeneic hematopoietic cell transplantation (HCT) as therapy for hematologic conditions is negatively impacted by the occurrence of graft-versus-host disease (GVHD). Tissue damage, caused, for example, by chemotherapy and radiotherapy, is a key factor in GVHD pathogenesis. Innate lymphoid cells (ILCs) are important mediators of tissue repair and homeostasis. The presence of ILCs before, and enhanced ILC reconstitution after, allogeneic HCT is associated with a reduced risk to develop mucositis and GVHD. However, ILC reconstitution after allogeneic HCT is slow and often incomplete. A way to replenish the pool of ILC relies on the differentiation of hematopoietic progenitor cells (HPCs) into ILC. METHODS: We developed an ex vivo stromal cell-containing culture system to study the capacity of HPCs to differentiate into all mature helper ILC subsets. RESULTS: ILC development depended on the source of HPCs. ILCs developed at high frequencies from umbilical cord blood- and fetal liver-derived HPC and at low frequencies when HPCs were obtained from allogeneic or autologous adult HCT grafts or healthy adult bone marrow. Although all helper ILC subsets could be generated from adult HPC sources, development of tissue protective ILC2 and NKp44+ ILC3 was notoriously difficult. CONCLUSIONS: Our data suggest that slow ILC recovery after allogeneic HCT may be related to an intrinsic incapability of adult HPC to develop into ILC.

Real-world evidence of heparin and citrate use in extracorporeal photopheresis: A hypothesis-generating data review of device settings and performance.

Extracorporeal photopheresis (ECP) is widely used for the treatment of cutaneous T-cell lymphoma, graft-vs-host disease, and other immune-related conditions. To avoid clotting during treatment, the ECP system used must be effectively primed with an anticoagulant. Heparin is the recommended anticoagulant for the THERAKOS CELLEX System, but acid citrate dextrose-A (ACDA) is often used. We compared system performance between these two anticoagulants for this ECP system. Deidentified data for ECP device performance were obtained at each treatment session, from automatically logged Smart Cards or labels completed by device operators. We compared the effects of ACDA or heparin on overall treatment duration, buffy coat (leukocyte) collection time, photoactivation time and the number of alarms and warnings. The variability in these parameters was also assessed. Data from 23 334 treat sessions were analyzed; ACDA was used in 34.4% and heparin in 65.6%. Overall, the ECP procedure duration, buffy coat collection time and photoactivation time were numerically similar regardless of whether ACDA or heparin was used, and regardless of needle mode. Photoactivation time variability was lower with ACDA compared with heparin in all needle modes. Among treatments that were completed automatically without any operator intervention, total treatment duration and photoactivation time were significantly reduced with ACDA use in both the double- and single-needle modes. The data presented indicate that, in both double- and single-needle modes, the THERAKOS® CELLEX® integrated ECP system performed similarly with ACDA compared to heparin, although ACDA demonstrated potential benefits in reducing variability in photoactivation time.

[Research Progress on the Roles of Rapamycin for the Prophylaxis and Treatment of Graft-Versus-Host Disease --Review].

Graft-versus-host disease (GVHD) reduces the clinical effect and life quality of patients after allogeneic hematopoietic stem cell transplantation (HSCT). Especially for steroid-resistant GVHD, it becomes essential to explore new prevention and treatment strategies. Rapamycin has shown certain clinical advantages in the prevention and treatment of acute and chronic GVHD by inhibiting the mTOR signal pathway. Furthermore, rapamycin exhibits the ability to regulate cell subsets, including T cells, B cell, dendritic cells and myeloidderived suppressor cells, which elucidates the mechanism on effective preventing and treating GVHD. This article reviewed the roles of mTOR inhibitor-rapamycin on GVHD, and discussed how to optimize the usage of rapamycin.

Mesenchymal Stem Cell Extracellular Vesicles as a New Treatment Paradigm in Solid Abdominal Organ Transplantation: A Case Series.

Solid abdominal organ transplantation is fraught with variable rates of rejection and graft versus host disease (GVHD). We sought to determine the safety and efficacy of an advanced extracellular vesicle (EV) investigational product (IP) derived from mesenchymal stem cells (MSC) in the transplant patient population. Seven separate emergency investigational new drug (eNIDs) were filed with the Food and Drug Administration (FDA) for the emergency treatment of rejection of an isolated intestinal graft (n = 2), liver allograft graft (n = 2), modified multivisceral graft (n = 3), and GVHD in isolated intestinal transplant patients (n = 2). Fifteen milliliters of IP was administered intravenously on Day 0, 2, 4, and this treatment cycle was repeated up to four times in each patient depending on the treatment protocol allowed by the FDA. Safety (adverse event reporting) and efficacy (clinical status, serologies, and histopathology) were evaluated. There were no adverse events related to IP. All patients had improvement in clinical symptoms within 24 h, improved serologic laboratory evaluation, improved pulmonary symptoms and dermatologic manifestations of GVHD, and complete histologic resolution of graft inflammation/rejection within 7 days of IP administration. Systemic use of a MSC-derived EV IP was successful in achieving histological clearance of intestinal, liver, and multivisceral graft inflammation, and skin and pulmonary manifestations of GVHD.

Placenta-Derived Decidua Stromal Cells: A New Frontier in the Therapy of Acute Graft-Versus-Host Disease.

Acute graft-versus-host disease (GVHD) is a frequent and potentially life-threatening complication following allogeneic hematopoietic cell transplantation (HCT). Mesenchymal stromal cells (MSCs), rare precursors found in all body tissues, possess immunosuppressive properties and can inhibit alloreactivity both in vitro and in vivo. Two decades ago, we introduced bone marrow-derived (BM) MSCs as a novel therapy for acute GVHD. While some patients responded to BM-MSCs, the response was not universal. Commercially available BM-MSCs are now used for acute GVHD treatment in Canada, Japan, and New Zealand. The fetus is protected from the mother's immune system by the placenta, and our research found that placenta-derived decidua stromal cells (DSCs) offer a stronger immunosuppressive effect than other sources of stromal cells. Safety studies in rabbits, rats, mice, and humans have shown negligible or no side effects from BM-MSCs or DSCs. In a phase I/II trial for severe acute GVHD, we treated 21 patients (median age, 49 years; range 1.6-72 years) with severe biopsy-proven gastrointestinal acute GVHD. The median cell dose of DSCs was 1.2 × 106 (range 0.9-2.9) cells/kg body weight, with a median of 2 (range 1-6) infusions given 1 week apart. The cell viability of DSCs was 93% (range, 69%-100%), and the median cell passage number was 4 (range, 2-4). All patients responded, with a complete response of acute GVHD in 11 patients and partial response in 10 and 1-year survival of 81%. Randomized trials are needed to prove the superiority of DSCs compared to ruxolitinib and/or other novel immunosuppressive therapies.