Acute Gastrointestinal Graft-versus-host Disease Research Articles

Bacteroides ovatus alleviates dysbiotic microbiota-induced graft-versus-host disease

Acute lower gastrointestinal GVHD (aLGI-GVHD) is a serious complication of allogeneic hematopoietic stem cell transplantation. Although the intestinal microbiota is associated with the incidence of aLGI-GVHD, how the intestinal microbiota impacts treatment responses in aLGI-GVHD has not been thoroughly studied. In a cohort of patients with aLGI-GVHD (n= 37), we found that non-response to standard therapy with corticosteroids was associated with prior treatment with carbapenem antibiotics and a disrupted fecal microbiome characterized by reduced abundances of Bacteroides ovatus. In a murine GVHD model aggravated by carbapenem antibiotics, introducing B.ovatus reduced GVHD severity and improved survival. These beneficial effects of Bacteroides ovatus were linked to its ability to metabolize dietary polysaccharides into monosaccharides, which suppressed the mucus-degrading capabilities of colonic mucus degraders such as Bacteroides thetaiotaomicron and Akkermansia muciniphila, thus reducing GVHD-related mortality. Collectively, these findings reveal the importance of microbiota in aLGI-GVHD and therapeutic potential of B.ovatus.

Gastrointestinal involvement refines prognosis in minnesota standard risk acute graft-vs.-host disease.

Minnesota acute graft versus host disease (AGVHD) risk score is a validated tool to stratify newly-diagnosed patients into standard-risk (SR) and high-risk (HR) groups with ~85% having SR AGVHD. We aimed to identify factors for further risk-stratification within Minnesota SR patients. A single-center, retrospective analysis of consecutive patients between 1/2010 and 12/2014 was performed. Patients who developed AGVHD within 100 days and treated with systemic corticosteroids were included (N = 416), 356 (86%) of which were Minnesota SR and 60 (14%) had HR AGVHD. Isolated upper gastrointestinal (GI) AGVHD patients had significantly better day 28 and 56 CR/PR rates (90% vs. 72%, p = 0.004) and (83% vs 66%, p = 0.01), respectively, and lower 1-year non-relapse mortality (NRM; 10% vs. 22%; HR 0.4, p = 0.03). Lower GI AGVHD had less favorable outcomes with 1-year NRM of 40% (HR 2.1, p = 0.001), although CR/PR rates were not statistically different. In multivariate analysis, lower GI involvement (HR 2.6, p < 0.001), age ≥ 50 (HR 2.9, p < 0.001) and HCT-CI > 3 (HR 2.1, p = 0.002) predicted for 1-year NRM. Heterogeneity within Minnesota SR patients requires consideration in clinical trials, as distinct outcomes are observed in those with isolated upper GI and lower GI AGVHD, highlighting the importance of stratification in clinical trial design.

Clinical Observation on Haploid Hematopoietic Stem Cells Combined with Umbilical Cord Blood Double Transplantation for Aplastic Anaemia in Children

To explore the efficacy and safety of haploidentical hematopoietic stem cell transplantation combined with umbilical cord blood infusion for the treatment of aplastic anaemia in children. Nine cases of children with aplastic anaemia treated with umbilical cord blood combined with haploidentical hematopoietic stem cell transplantation at the People's Hospital of Henan University of Chinese Medicine from January 1, 2021 to September 15, 2023 with a median age of 11(2-13) years and a median follow up of 18(7.5-21) months were included, and the clinical data were retrospectively analyzed. Hematopoiesis reconstitution, the incidence of graft-versus-host disease(GVHD), infections and survival of the patients were analyzed. All 9 children were successfully implanted. The median time to neutrophil and platelet implantation was 11.11±1.27 d and 12.44±3.36 d, respectively. One case developed acute gastrointestinal GVHD of degree I, which was improved after treatment, and the patient developed superficial gastritis and chronic gastrointestinal GVHD at a later stage, which is currently under clinical follow-up. Acute GVHD of II-IV degree was 0%. Hemorrhagic cystitis in 3 cases, CMV infection in 5 cases and bacterial and fungal infections in 5 cases improved with symptomatic treatment.All 9 children demonstrated complete donor chimerism within 1 month after transplantation, at two years of follow-up, all nine children survived without recurrence or development of grade II-IV GVHD, and there were no children with transplant-related deaths. Haploidentical hematopoietic stem cell transplantation combined with umbilical cord blood transfusion for aplastic anaemia in children has a low incidence and mild degree of GVHD, with significant efficacy, and can be used as a therapeutic option for children without an HLA full donor chimeric match.

Analysis of the efficacy and prognostic factors of allogeneic hematopoietic stem cell transplantation in patients with myelodysplastic syndrome with blastomycosis and survival comparison of different subtypes after the WHO 2022 reclassification

Objective: To evaluate the efficacy and prognostic factors of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with myelodysplastic syndrome accompanied by myelodysplasia (MDS-EB) and to compare the prognosis of different subtypes of patients classified by World Health Organization (WHO) 2022. Methods: A total of 282 patients with MDS-EB who underwent allo-HSCT at the Hematology Hospital of the Chinese Academy of Medical Sciences from October 2006 to December 2022 were included in the study. The WHO 2022 diagnostic criteria reclassified MDS into three groups: myelodysplastic tumors with type 1/2 of primitive cell proliferation (MDS-IB1/IB2, 222 cases), MDS with fibrosis (MDS-f, 41 cases), and MDS with biallelic TP53 mutation (MDS-biTP53, 19 cases). Their clinical data were retrospectively analyzed. Results: ① The median age of 282 patients was 46 (15-66) years, with 191 males and 91 females. Among them, 118 (42% ) and 164 (58% ) had MDS-EB1 and MDS-EB2, respectively. ②Among the 282 patients, 256 (90.8% ) achieved hematopoietic reconstruction after transplantation, with 11 (3.9% ) and 15 (5.3% ) having primary and secondary implantation dysfunctions, respectively. The cumulative incidence of acute graft-versus-host disease (GVHD) 100 days post-transplantation was (42.6±3.0) %, and the cumulative incidence of grade Ⅱ-Ⅳ acute GVHD was (33.0±2.8) %. The cumulative incidence of chronic GVHD 1 year post-transplantation was (31.0±2.9) %. Post-transplantation, 128 (45.4% ), 63 (22.3% ), 35 (12.4% ), and 17 patients (6.0% ) developed cytomegalovirus infection, bacteremia, pulmonary fungal infection, and Epstein-Barr virus infection. ③The median follow-up time post-transplantation was 22.1 (19.2-24.7) months, and the 3-year overall survival (OS) and disease-free survival (DFS) rates were 71.9% (95% CI 65.7% -78.6% ) and 63.6% (95% CI 57.2% -70.7% ), respectively. The 3-year non-recurrent mortality rate (NRM) is 17.9% (95% CI 13.9% -22.9% ), and the 3-year cumulative recurrence rate (CIR) is 9.8% (95% CI 6.7% -13.7% ). The independent risk factors affecting OS post-transplantation include monocyte karyotype (P=0.004, HR=3.26, 95% CI 1.46-7.29), hematopoietic stem cell transplantation complication index (HCI-CI) of ≥3 points (P<0.001, HR=2.86, 95% CI 1.72-4.75), and the occurrence of acute gastrointestinal GVHD of grade Ⅱ-Ⅳ (P<0.001, HR=5.94, 95% CI 3.50-10.10). ④The 3-year OS and DFS rates in the MDS-IB1/IB2 group post-transplantation were better than those in the MDS-biTP53 group [OS: 72.0% (95% CI 63.4% -80.7% ) vs 46.4% (95% CI 26.9% -80.1% ), P=0.020; DFS: 67.4% (95% CI 60.3% -75.3% ) vs 39.7% (95% CI 22.3% -70.8% ), P=0.015]. The 3-year CIR was lower than that of the MDS-biTP53 group [7.3% (95% CI 4.3% -11.4% ) vs 26.9% (95% CI 9.2% -48.5% ), P=0.004]. The NRM at 3 years post-transplantation in the MDS-IB1/IB2, MDS-f, and MDS-biTP53 groups were 16.7% (95% CI 12.1% -22.1% ), 20.5% (95% CI 9.4% -34.6% ), and 26.3% (95% CI 9.1% -47.5% ), respectively (P=0.690) . Conclusion: Allo-HSCT is an effective treatment for MDS-EB, with monomeric karyotype, HCI-CI, and grade Ⅱ-Ⅳ acute gastrointestinal GVHD as independent risk factors affecting the patient's OS. The WHO 2022 classification helps distinguish the efficacy of allo-HSCT in different subgroups of patients. Allo-HSCT can improve the poor prognosis of patients with MDS-f, but those with MDS-biTP53 have a higher risk of recurrence post-transplantation.

High sensitivity of host Helios+/Neuropilin-1+ Treg to pretransplant conditioning hampers development of OX40bright/integrin-β7+ regulatory cells in acute gastrointestinal GvHD.

This study sought to compare the behavior of Treg subsets displaying different coexpression patterns of Neuropilin-1 (Nrp1) and Helios, under the influence of gut stress unrelated to hematopoietic stem cell transplantation, pretransplantation conditioning, and posttransplant gastrointestinal acute graft versus host disease (GI-aGvHD). Host CD4+/CD25hi/Foxp3+ Treg cells, identified by flow cytometry, were isolated from various tissues of mice affected by these stressors. Expression of CD25, CTLA-4, CD39, OX40, integrin-β7, LAG3, TGFβ/LAP, granzyme-A, -B, and interleukin-10 was compared in four Treg subsets displaying Helios or Nrp1 only, both or none. Fluorescence-activated cell sorter-sorted Treg subsets, displaying markers affected in a conditioning- and GI-aGVHD-restricted manner, were further investigated by transcriptome profiling and T-cell suppression assays. We found that conditioning by irradiation greatly diminished the relative frequency of Helios+/Nrp1+ Treg, shifting the balance toward Helios-/Nrp1- Treg in the host. Upregulation of integrin-β7 and OX40 occurred in GI-aGvHD-dependent manner in Helios+/Nrp1+ cells but not in Helios-/Nrp1- Treg. Sorted Treg subsets, confirmed to overexpress Nrp1, Helios, OX40, or integrin-β7, displayed superior immunosuppressive activity and enrichment in activation-related messenger RNA transcripts. Our data suggest that conditioning-induced shrinkage of the Nrp1+/Helios+ Treg subset may contribute to the development of GI-GvHD by impairing gut homing and decreasing the efficiency of Treg-mediated immunosuppression.

Significant impact of antibiotic exposure on GI-GVHD, NRM, and GRFS following allogeneic HCT with non-myeloablative Flu-TBI conditioning

Background Acute gastro-intestinal graft-versus-host disease (GI-GVHD) and non-relapse mortality (NRM) after allogeneic HCT are closely related to loss of microbial diversity and intestinal dominance by single taxa resulting from the use of antibiotics, dietary changes, and mucosal barrier injury. There is a paucity of data on the impact of use of antibiotics in HCT after Flu-TBI-based non-myeloablative (NMA) conditioning where there is absence of mucositis and limited malnutrition. Methods We did a retrospective single-center analysis of patients receiving Flu-TBI-based NMA HCT for a high-grade myeloid malignancy, mostly AML, and MDS, or acute lymphoblastic leukemia (ALL). We analyzed the impact of pre-engraftment antibiotic exposure, prophylactic ciprofloxacin, and or treatment with broad-spectrum cephalosporin/carbapenem, on HCT outcomes, with a focus on the incidence of acute GI-GVHD by day 180 and NRM at 1 year. Results A total of 150 patients were evaluable with a median age of 62 years. Antibiotics were used in 90 patients; 60 prophylactic use only and 30 therapeutic use with or without previous prophylaxis. Antibiotic use resulted in a significant higher incidence of GI-GVHD Stage 1–4; 29% (26/90) versus 5% (3/60) in those not receiving antibiotics (OR 8.1 (95% CI 2.3–28.3), p = 0.001). Use of antibiotics resulted in higher 1-year NRM (19% (17/90) versus 10% (6/60), HR 2.3, p = 0.06), and decreased 2-year GRFS (42% (38/90) versus 55% (33/60), HR 1.7, p = 0.04), but did not impact RFS or OS. Conclusions Use of antibiotics was related to the occurrence of GI-GVHD, NRM, and GRFS in patients receiving truly NMA HCT. Therefore, in the absence of mucositis and low incidence of bacteremia, antibiotics can and should be used restrictively in this setting.

Effective treatment of Clostridioides difficile infection improves survival and affects graft-versus-host disease: a multicenter study by the Polish Adult Leukemia Group

Clostridioides difficile infection (CDI) is the most common cause of infectious diarrhea after allogeneic hematopoietic cell transplantation (allo-HCT). The impact of CDI and its treatment on allo-HCT outcomes and graft-versus-host disease (GVHD), including gastrointestinal GVHD (GI-GVHD) is not well established. This multicenter study assessed real-life data on the first-line treatment of CDI and its impact on allo-HCT outcomes. Retrospective and prospective data of patients with CDI after allo-HCT were assessed. We noted statistically significant increase in the incidence of acute GVHD and acute GI-GVHD after CDI (P = 0.005 and P = 0.016, respectively). The first-line treatment for CDI included metronidazole in 34 patients, vancomycin in 64, and combination therapy in 10. Treatment failure was more common with metronidazole than vancomycin (38.2% vs. 6.2%; P < 0.001). The need to administer second-line treatment was associated with the occurrence or exacerbation of GVHD (P < 0.05) and GI-GVHD (P < 0.001) and reduced overall survival (P < 0.05). In the multivariate analysis, the risk of death was associated with acute GVHD presence before CDI (hazard ratio [HR], 3.19; P = 0.009) and the need to switch to second-line treatment (HR, 4.83; P < 0.001). The efficacy of the initial CDI treatment affects survival and occurrence of immune-mediated GI-GVHD after allo-HCT. Therefore, agents with higher efficacy than metronidazole (vancomycin or fidaxomicin) should be administered as the first-line treatment.

A randomized phase 2 trial of oral vitamin A for graft-versus-host disease in children and young adults

AbstractVitamin A plays a key role in the maintenance of gastrointestinal homeostasis and promotes a tolerogenic phenotype in tissue resident macrophages. We conducted a prospective randomized double-blinded placebo-controlled clinical trial in which 80 recipients of hematopoietic stem cell transplantation (HSCT) were randomized 1:1 to receive pretransplant high-dose vitamin A or placebo. A single oral dose of vitamin A of 4000 IU/kg, maximum 250 000 IU was given before conditioning. The primary end point was incidence of acute graft-versus-host disease (GVHD) at day +100. In an intent-to-treat analysis, incidence of acute GVHD was 12.5% in the vitamin A arm and 20% in the placebo arm (P = .5). Incidence of acute gastrointestinal (GI) GVHD was 2.5% in the vitamin A arm (P = .09) and 12.5% in the placebo arm at day +180. Incidence of chronic GVHD was 5% in the vitamin A arm and 15% in the placebo arm (P = .02) at 1 year. In an “as treated” analysis, cumulative incidence of acute GI GVHD at day +180 was 0% and 12.5% in recipients of vitamin A and placebo, respectively (P = .02), and cumulative incidence of chronic GVHD was 2.7% and 15% in recipients of vitamin A and placebo, respectively (P = .01). The only possibly attributable toxicity was asymptomatic grade 3 hyperbilirubinemia in 1 recipient of vitamin A at day +30, which self-resolved. Absolute CCR9+ CD8+ effector memory T cells, reflecting gut T-cell trafficking, were lower in the vitamin A arm at day +30 after HSCT (P = .01). Levels of serum amyloid A-1, a vitamin A transport protein with proinflammatory effects, were lower in the vitamin A arm. The vitamin A arm had lower interleukin-6 (IL-6), IL-8, and suppressor of tumorigenicity 2 levels and likely a more favorable gut microbiome and short chain fatty acids. Pre-HSCT oral vitamin A is inexpensive, has low toxicity, and reduces GVHD. This trial was registered at www.ClinicalTrials.gov as NCT03202849.

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.

Research advances on short-chain fatty acids in gastrointestinal acute graft-versus-host disease.

Gastrointestinal acute graft-versus-host disease (GI-aGVHD) is a severe early complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT). It has been shown that the intestinal microbiota plays a critical role in this process. As metabolites of the intestinal microbiota, short-chain fatty acids (SCFAs) are vital for maintaining the host-microbiota symbiotic equilibrium. This article provides an overview of the protective effect of SCFAs in the gastrointestinal tract, emphasizes their association with GI-aGVHD, and explores relevant research progress in prevention and treatment research.

Clinical Characteristics, Management, and Allogeneic Hematopoietic Cell Transplantation of Patients with Toll-like Receptor 8 Gain-of-Function Mutations

Toll-like receptor 8 gain-of-function (TLR8 GOF) is a recently described inborn error of immunity due to germline or somatic mutations in the TLR8 gene and characterized by severe neutropenia, infections, lymphoproliferation, humoral immune defects, and in some cases, bone marrow failure. Treatment of TLR8 GOF has been challenging to date, and guidance for optimal therapy is lacking. We describe the clinical characteristics and management of 10 patients with TLR8 GOF variants, including the first female patient and further clinical outcome on the 6 patients initially reported with this disease with a focus on the role of allogeneic hematopoietic cell transplantation (HCT). All but one patient were male ranging from 0.5 months to 28 years at age of symptom onset. Eight patients had somatic mutations with variant allele frequencies of 7-26%; two patients had germline mutations. The 9 male patients all had severe neutropenia and varying degrees of anemia and/or thrombocytopenia. Oral ulcers, recurrent infections, hepatosplenomegaly, and hypogammaglobulinemia were common. Immune phenotype was variable, ranging from severe lymphopenia to marked T cell lymphoproliferation. Several patients had an inverted CD4:CD8 T cell ratio and skewing of T cell subsets to the terminal effector memory phenotype. Increased double-negative T cells were also observed. All patients had low class switched memory B cells. Bone marrows were hypo- to hypercellular with marked myeloid hypoplasia, and in most cases, with increased T cells, large granular lymphocytes, and/or lymphoid aggregates. Neutropenia was initially responsive to granulocyte colony stimulating factor (GCSF) +/- steroids in several patients but ultimately become refractory to therapy. Immunomodulatory agents and chemotherapy were unsuccessful. Six patients underwent allogeneic HCT; two patients died at 8 and 18 years without definitive therapy; and one patient was lost to follow-up. The female patient had germline disease and presented with pure red blood cell aplasia at 2 weeks of life and is scheduled to undergo HCT. Transplant data were available for 5 of 6 patients who underwent HCT. Age at transplant was 3 to 21 years. One patient who received a graft from a 7/8 HLA-matched unrelated donor developed severe veno-occlusive disease and secondary graft failure. The patient underwent a second transplant and ultimately died. Another patient received a matched sibling donor HCT while critically ill from Candida lusitaniae and mucormycosis infection with associated multisystem organ failure. The patient engrafted with 100% donor chimerism but died on day +15 post-HCT. The remaining 3 patients are alive and well 8 months to 2 years post-HCT. Two patients received grafts from HLA-matched donors (1 sibling and 1 unrelated) with reduced intensity conditioning and cyclophosphamide, mycophenolate mofetil and vorinostat for graft-versus-host disease (GVHD) prophylaxis. The third patient underwent a haploidentical HCT with myeloablative conditioning and post-transplant cyclophosphamide. Post-HCT complications included acute skin and/or gastrointestinal GVHD that was responsive to therapy in all patients, and severe lung GVHD in one patient. There were no major infectious complications. All three patients had full donor chimerism in myeloid and T cells with complete resolution of disease phenotype at last follow-up. The patient for whom detailed transplant data is not available received a haploidentical HCT. He developed mixed myeloid chimerism for which he received multiple donor lymphocyte infusions and was alive at last contact &amp;gt;3 years post-HCT. TLR8 GOF should be considered in male and female patients with severe, unexplained neutropenia refractory to GCSF, and particular care should be taken when investigating for mutations given the disease-causing variant allele frequencies as low as 7%. Neutropenia and immune dysregulation were refractory to all therapies in our cohort, and TLR8 GOF was fatal in two patients who did not receive definitive therapy. Allogeneic HCT is curative and should be considered without delay for medically suitable patients.

Highly Multiplexed Immunohistochemistry Can Predict Steroid Refractory Gastrointestinal (GI) Acute Gvhd at the Time of Endoscopy

Background: For patients with high-risk hematologic disease, hematopoietic cell transplant (HCT) often represents the only option for cure. However, HCT is fraught with complications, leading to morbidity and mortality. Acute GVHD (aGVHD), specifically steroid refractory (SR) GI aGVHD, is a major cause of early mortality. Two issues with SR GI aGVHD predominate: (1) We do not understand the mechanisms differentiating SR vs steroid sensitive (SS) GI aGVHD; (2) We do not have an accurate test to predict SR vs SS GI aGVHD at the time of endoscopic evaluation. Here, we used state-of-the-art multiplexed immunohistochemistry (IHC) to interrogate immune mediators of GI aGVHD, and to develop a robust assay capable of predicting SR vs SS disease from standard GI biopsies. Methods: We analyzed all HCT patients at Boston Children's Hospital (BCH) from 1/2014-12/2021 (n=551) who received a first lower GI endoscopy for suspected GI aGVHD (n=109). We tracked their SS vs SR status and their Overall Survival (OS) through 2 yr post-HCT. Classic histology was performed and in addition, each sigmoid colon biopsy (formalin-fixed) was analyzed with a series of novel multiplexed IHC panels (interrogating Pan-CK, DAPI, CD3, CD8, CD20, FoxP3, GITR, CD68, Granzymes B and K, CD103, Ki67, ECP, NCR1, BCMA, CD11c, and MPO, with quantitative image analysis performed using HALO Indica Labs Hyperplex module). Density/proportions of multiple cellular infiltrates and their ratios were assessed. Receiver Operator Characteristic (ROC) and K-nearest neighbors (KNN) classification were used to distinguish SS from SR aGVHD. Results: Of 109 biopsies, 60 had histologic evidence of lower GI aGVHD inflammation, 12 had other GI inflammation (eg infections, drug effects) and were not further analyzed, and 15 did not have inflammation and therefore were not diagnosed with histologic aGVHD (termed ‘No Inflammation’ (NI). In an additional 22 biopsies, histology was characterized as “Rare Apoptosis” (RA), a diagnosis for which there is no national consensus about severity or the need for steroid treatment. At BCH, the vast majority of patients with RA on endoscopy were treated as not having aGVHD (with only 3/22 receiving steroids, and all 3 being SS). We tracked OS and IHC characteristics for SS aGVHD, SR aGVHD, NI and RA. Fig 1 shows 2 yr OS, which confirms the inferior OS of SR vs SS aGVHD (SR: 58% vs SS: 93% p &amp;lt;0.0001). Importantly, Fig 1 demonstrates that even without steroids, the OS of RA was equivalent to no GI aGVHD (NI: 89% vs RA: 86% p = 0.74). Multiplexed IHC (performed on 68 biopsies from sequential cases collected from 1/2018-12/2021) was associated with several novel findings ( Fig 2): (1) By IHC, RA had fewer immune infiltrates vs aGVHD and NI: CD3 density: aGVHD (both SS and SR combined): 782 ± 133, NI: 386 ± 37, RA: 165 ± 26, p = 9.5x10 -5; CD8 density: aGVHD: 381 ± 83, NI: 123 ± 24, RA: 42 ± 26, p&amp;lt;0.001; CD4 conventional T cells (CD4 Tconv): aGVHD: 359 ± 47, NI: 237 ± 23, RA: 114 ± 19, p&amp;lt;0.001. Ratios of immune infiltrates also distinguished the 3 subtypes: the ratio of CD8:CD4 Tconv: aGVHD: 0.95 ± 0.14; NI: 0.59 ± 0.10 RA: 0.44 ± 0.29 p = 0.013; CD8:CD68: aGVHD: 0.35 ± 0.03, NI: 0.26 ± 0.04 RA: 0.11 ± 0.02, p&amp;lt;0.001. CD8:Epithelial cells (epi): aGVHD: 0.153 ± 0.04; NI: 0.045 ± 0.01; RA: 0.014 ± 0.003, p&amp;lt;0.001. These results underscore the immunologically benign nature of RA, predicting its superior OS. Importantly, multiplexed IHC could distinguish SR vs SS aGVHD at the time of endoscopy, a finding with major clinical implications. For example, amongst other distinguishing IHC characteristics, the ratio of CD8:CD4Tconv: SR: 1.3 ± 0.22 vs SS: 0.68 ± 0.15 p&amp;lt; 0.01; CD8:epi: SR: 0.220 ± 0.008 vs SS: 0.106 ± 0.042 p = 0.04). A KNN-based classifier identified thresholds with high accuracy (81%), specificity (69%), sensitivity (93%); AUC = 0.852 for SS vs SR aGVHD ( Fig 2). Conclusions: We used state-of-the-art multiplexed IHC to interrogate the immune cells associated with GI aGVHD, with 2 major findings: We find RA associated with superior OS without steroid treatment, and with minimal immune infiltration, confirming its benign nature. We also created a novel multiplexed IHC assay capable of accurately classifying SR vs SS aGVHD from standard-of-care biopsy specimens. If confirmed in a multicenter setting, this would be a major advance, allowing physicians to tailor appropriate therapies to patients at highest risk of developing SR GI aGVHD at the time of initial endoscopic evaluation.

Inb-100: A Pilot Study of Donor Derived, Ex-Vivo Expanded/Activated Gamma-Delta T Cell (EAGD) Infusion Following Haploidentical Hematopoietic Stem Cell Transplantation and Post-Transplant Cyclophosphamide (PTCy)

Background: Gamma-delta (gd) T cells are MHC unrestricted lymphocytes that recognize and lyse malignant cells in allogeneic settings. Although haploidentical transplant with PTCy has reduced the risk of graft-versus-host disease (GvHD); the incidence of relapse remains up to 50% at year 1. Early post-transplant infusion of haploidentical EAGD cells may decrease relapse risk through a graft-versus-leukemia (GvL) effect without severe GvHD. We present updated clinical and correlative data from our Phase I trial using our recommended phase 2 dose (RP2D). Methods: Adults with newly diagnosed or relapsed ALL, CML, AML undergoing first haploidentical transplant with reduced-intensity flu/cy/TBI conditioning received EAGD intravenously within 7 days of neutrophil engraftment. Peripheral blood was collected at EAGD infusion and monthly through day 90, with additional collections every 6 months through 1 year. Primary endpoints include dose-limiting toxicities (DLT), grade (G) 3-4 adverse events including GvHD with secondary endpoints of relapse and overall survival. Biologic parameters included multiparameter flow cytometric immunophenotyping and additional serum cytokine analysis using the Olink ® 48 target panel. Results: 14 subjects were enrolled with 4 treated at Dose Level (DL) 1 of 1 x 10 6 EAGD/kg and 6 subjects treated at the RP2D of DL2 (3 x 10 6 EAGD/kg). Untreated subjects included: One screen failure, a manufacturing failure, one subject who died prior to dosing, and one subject who received an out of study specification product. Treated subjects were 60% male, median age of 68, and primarily AML subjects in CR1. RP2D was defined by an acceptable toxicity profile, no DLT's, prolonged RFS and elevated gd levels. Peripheral lymphodepletion persisted through the first 100 days post-BMT followed by T cell recovery from a CD45+CD27-effector phenotype to central and effector memory phenotype. Notably, DL2 showed significant increases in gd T cell count recovery at days 60, 100 and 180 post-BMT vs. DL1 and historically untreated Haplo/PTCy patients, p = &amp;lt;0.05. NK cells remained within the low normal range and &amp;lt;3% of circulating T cells were Tregs. Preliminary serum cytokine analysis revealed elevated IL-6 and IL-15 in serum post- transplant prior to EAGD infusion, but dropped to normal median levels at day 60, 20-30 days after EAGD infusion. One subject received intermittent hypomethylating therapy for emergence of recipient chimerism. Treatment emergent AE's included transient WBC and ANC decreases (100% each), platelet count decrease and anemia (88.9% each) and maculopapular rash, hypomagnesemia and blood creatine increased (55.6% each). EAGD related toxicities were primarily G1-2, included G1-2 skin acute GvHD and gastrointestinal GvHD, and one case of G3 platelet count decrease. Treatment related serious AE's of G3 nausea and G2 rash were reported. No DLTs, neurotoxicity, cytokine release syndrome or treatment related deaths were reported. Conclusions: Post-BMT infusion of donor-derived, EAGD cells has demonstrated manageable safety with no infusional toxicity or ≥G3 acute GvHD or extensive chronic GvHD. Durable relapse free survival at a maximum of &amp;gt;3 years in subjects with poor risk cytogenetics and adverse clinical risk factors combined with ongoing homeostatic reconstitution of increasing gd T cell effectors post-BMT suggests this therapy may be an effective measure in mitigating relapse after HaploBMT. NCT03533816

Budesonide Added to Post-Transplantation Cyclophosphamide, Tacrolimus and Mycophenolate Mofetil for Prevention of Graft-Versus-Host Disease

Background: Topically active corticosteroids have been shown to effectively treat inflammatory bowel disease with a systemic steroid-sparing effect. However, previous studies have not demonstrated their efficacy in preventing graft-versus-host disease (GVHD) when combined with the standard GVHD prophylaxis regimen consisting of calcineurin inhibitors and methotrexate. We hypothesized that the addition of orally administered ileal-controlled-release budesonide to the post-transplant cyclophosphamide (PTCy)-based regimen could effectively prevent severe acute gastrointestinal GVHD. In this study, we present outcomes of the first 43 consecutively treated patients (pts) with the PTCy-tacrolimus (T), mycophenolate mofetil (M) and budesonide (B) (PTCy-TMB) as a GVHD prophylaxis regimen after allogeneic stem cell transplantation (alloSCT). Methods: Pts with hematologic malignancies received their first alloSCT at our institution between 05/2020-04/2023. Thirty one pts received conditioning with fludarabine (160 mg/m 2) + melphalan (100-140 mg/m 2) + TBI (2-4Gy) or thiotepa 5 mg/kg. Twelve pts received fludarabine (150mg/m 2) + cyclophosphamide (29mg/kg) and TBI 4Gy ± ATG (4.5 mg/kg). GVHD prophylaxis consisted of Cy (50 mg/kg on D+3 and +4), T (trough goal 6-10 ng/mL), M (15mg/kg TID) and budesonide (3 mg TID) starting on D+5 and continued until D+90 followed by a weekly taper if no acute GVHD (aGVHD) occurred. T was continued for at least 6 months followed by a taper, unless otherwise indicated. Results: The median age was 50 years (range 22-73), 39 pts had hematologic malignancies including AML (N=14), ALL (N=11) and NHL (N=8). Seven pts (16%) classified as high/very-high DRI. The median of HCT-CI was 4 (range 0-7). Donors were haploidentical (N=32), MSD (N=8), MUD (N=1), MMSD (1) and MMUD (N=1). PBSCs were used in 28 pts (65%). Thirty pts (70%) received RIC regimens. Median follow-up was 407 days (range 91-996 days). At day 100, the cumulative incidence (CI) of grade 2 aGVHD was 7.0% (95%CI 1.8-17.2), while none developed grade 3-4 aGVHD (Figure 1). One patient had severe chronic GVHD (bronchiolitis obliterans) with CI at 2 years of 3.2% (95%CI 0-14.0). The CI of any systemic steroid use at D+100 and D+180 was 30.2% (95%CI 17.4-44.1) and 44.8% (95%CI 28.9-59.5), respectively. Among the pts who received treatment for aGVHD, the median cumulative systemic steroid exposure (in prednisone equivalents) was 1,318 mg (IQR 623-3,775) at D+100 and 1,325 mg (IQR 525-1,640) at D+180, with a median treatment duration of 40 days (IQR 25-110). At 1 year, the OS, PFS, GRFS, relapse and NRM were 79.6% (95%CI 61.4-89.9), 69.8% (95%CI 51.6-82.3), 66.6% (95%CI 48.4-79.8), 15.3% (95%CI 6.2-28.2) and 14.9% (95%CI 5.3-29.1), respectively. The 1-year CI of newly diagnosed/worsening hyperglycemia and Cushing syndrome was 18.2% (95%CI 7.9-31.9) and 5.0% (95%CI 0.9-14.2), respectively. 3 pts (7%) required insulin treatment. The median absolute lymphocyte count (ALC) at day 30, 90 and 180 was 200/mcL, 300/mcL and 500/mcL, respectively, with no differences in the median ALC at D+180 among pts with and without GVHD. Median cell numbers of CD3 +, CD3 +/CD4 +, CD3 +/CD8 +, CD19 + and CD56 + at 1, 3, 6 months post-transplant were D+30 - 63/mcL, 18/mcL, 34/mcL, 1/mcL, 87/mcL, D+90 - 111/mcL, 64/mcL, 34/mcL, 9/mcL, 216/mcL and D+180 - 269/mcL , 78/mcL , 126/mcL , 7/mcL, 189/mcL, respectively. After 10/2022 pts were tested routinely for Reg3α and ST2 (baseline and retested if developed any signs/symptoms of aGVHD). Among 18 tested pts at baseline, the median number (range) of Reg3α and ST2 at baseline was 28 ng/mL (16-90) and 23,308 pg/mL (4,678-56,226), respectively. Three low-risk pts developed grade 1 aGVHD (N=2) and grade 2 aGVHD (N=1). Fourteen pts with GI sign/symptoms after transplant showed median number (range) of Reg3α and ST2 of 78 ng/mL (16-837) and 34,904 pg/mL (13,329-160,000), respectively. Only one pt with high-risk aGVHD algorithm developed grade 2 aGVHD (Figure 1). Conclusions: The addition of budesonide to PTCy-based GVHD prophylaxis regimen (PTCy-TMB) is feasible and appears to be effective in preventing severe GI aGVHD, without compromising transplant outcomes and immunologic reconstitution.

Successful Treatment Outcomes of Hematopoietic Stem Cell Transplantation with Reduced-Toxicity Conditioning Regimen Incorporating Treosulfan in Pediatric Patients with XIAP Deficiency

Background X-linked inhibitor of apoptosis (XIAP) defciency is an inherited primary immunodefciency characterized by chronic infammasome overactivity and associated with hemophagocytic lymphohistiocytosis (HLH) and infammatory bowel disease (IBD). Although hematopoietic stem celltransplantation (HSCT) is the only curative therapy, the outcomes of HSCT for XIAP deficiency remain unsatisfactory. Methods We have performed HSCT with treosulfan based RTC regimen for pediatric patients with non-malignant disorders since January 2016, and reviewed the medical records of patients with XIAP deficiency who underwent treosulfan based HSCT to investigate outcomes of HSCT for patients with XIAP deficiency. Results Since January 2016, 4 patients with XIAP deficiency had undergone HSCT using RTC regimen consisted of fludarabine (150-180 mg/m 2), treosulfan (42 g/m 2), rabbit ATG (5-7.5 mg/kg), and thiotepa (10 mg/kg). All patients were male and received HSCT (2 from URD and 2 from HFD) at median 13.7 years old (range, 12.8-15.3), median 2 years (range, 0.5-3.9) after diagnosis of XIAP. They all achieved engraftment and complete donor chimerism at the time of last evaluation. One patient who received HFD HSCT developed acute GI GVHD grade 3 and VOD within 1 month from HSCT, which was recovered after treatment with systemic steroid and defibrotide. Except the patient, there was no fatal acute regimen related toxicity ≥ CTCAE grade 3. Two patients developed chronic GVHD: one had limited disease which was resolved after systemic steroid therapy and the other had extensive disease. During the median 43 months (range, 33.1-63.0) follow-up, all survived without disease recurrence. Conclusions HSCT with treosulfan based RTC regimen is promising treatment option for pediatric patients with XIAP deficiency, with successful engraftment and low treatment-related toxicity. However, further studies including a larger multicenter trial and measures to refine the regimen are mandate to verify efficacy and safety of this regimen.

Spatial transcriptomics reveals distinct tissue niches linked with steroid responsiveness in acute gastrointestinal GVHD

AbstractSevere acute graft-versus-host disease (aGVHD) is associated with significant mortality and morbidity, especially in steroid-resistant (SR) cases. Spatial transcriptomic technology can elucidate tissue-based interactions in vivo and possibly identify predictors of treatment response. Tissue sections from 32 treatment-naïve patients with biopsy-confirmed lower gastrointestinal (GI) aGVHD were obtained. The GeoMx digital spatial profiler was used to capture transcriptome profiles of >18 000 genes from different foci of immune infiltrates, colonic epithelium, and vascular endothelium. Each tissue compartment sampled showed 2 distinct clusters that were analyzed for differential expression and spatially resolved correlation of gene signatures. Classic cell-mediated immunity signatures, normal differentiated epithelial cells, and inflamed vasculature dominated foci sampled from steroid-sensitive cases. In contrast, a neutrophil predominant noncanonical inflammation with regenerative epithelial cells and some indication of angiogenic endothelial response was overrepresented in areas from SR cases. Evaluation of potential prognostic biomarkers identified ubiquitin specific peptidase 17–like (USP17L) family of genes as being differentially expressed in immune cells from patients with worsened survival. In summary, we demonstrate distinct tissue niches with unique gene expression signatures within lower GI tissue from patients with aGVHD and provide evidence of a potential prognostic biomarker.

Impact of the histologic grade of acute gastrointestinal graft-versus-host disease on outcomes in pediatric patients treated with allogeneic hematopoietic stem cell transplantation.

Acute gastrointestinal graft-versus-host disease (GVHD) is a common life-threatening complication after hematopoietic stem cell transplantation (HCT). We aimed to investigate outcomes according to the clinical, endoscopic, and histologic severity of gastrointestinal GVHD in pediatric patients treated with allogeneic HCT. This retrospective cohort study included pediatric patients who underwent sufficient endoscopic and histopathologic evaluation for clinically suspected acute gastrointestinal GVHD between 2010 and 2020. Fifty-one patients were included (male proportion, 68.6% [35/51]; median age at HCT, 6.4 years). When the patients were classified according to the histologic severity of gastrointestinal GVHD, the severe group had an earlier onset of GVHD symptoms and a higher proportion of patients with severe clinical gastrointestinal GVHD than the mild-to-moderate and "absent" groups. In Cox proportional hazards regression analysis, the groups with more severe clinical and histologic gastrointestinal GVHD showed a higher risk of non-relapse mortality (NRM). The 5-year overall survival (OS) rates were 58.3 and 36.4% in the mild-to-moderate and histologic gastrointestinal GVHD groups, respectively (p = 0.0384). Patients with higher clinical and histologic grades of gastrointestinal GVHD showed higher cumulative incidence of NRM. Our results demonstrated that histologic severity of gastrointestinal GVHD is a relevant factor affecting OS and NRM, and patients with mild-to-moderate or severe histologic gastrointestinal GVHD have worse outcomes than patients without histologic GVHD. These findings support the importance of assessing the histologic grade in the diagnostic evaluation of patients with clinical gastrointestinal GVHD.

Pooled allogeneic faecal microbiota MaaT013 for steroid-resistant gastrointestinal acute graft-versus-host disease: a single-arm, multicentre phase 2 trial

Failure of gastrointestinal acute graft-versus-host disease (GI-aGvHD) to respond to steroid therapy is associated with limited further therapeutic options. We aimed to assess the safety and efficacy of the first-in-human use of the pooled allogeneic faecal microbiota, MaaT013, for the treatment of steroid-refractory GI-aGvHD. This prospective, international, single-arm, phase 2a study reports clinical outcomes from a 24-patient cohort with grade III-IV, steroid refractory GI-aGvHD treated with the pooled allogeneic faecal microbiota MaaT013. MaaT013 involved pooling faecal matter from 3 to 8 screened donors then transplanting the pooled batches into patients to treat GI-aGVHD. The 24 patients were treated in the HERACLES study (Aug 2018 to Nov 2020) at 26 sites in Europe and an additional 52 patients were treated in a compassionate use/expanded access program (EAP) in France (July 2018 to April 2021). The primary endpoint was GI response at day 28, defined as the proportion of patients with GI-aGvHD who had a complete response (CR) or very good partial response (VGPR). GvHD grading and staging were assessed according to the revised Glucksberg criteria. Adverse events and severe adverse events were monitored for 6 months and 12 months, respectively. The HERACLES study was registered with ClinicalTrials.gov (NCT03359980). Compared with single donors, MaaT013 is characterised by higher microbial richness and reduced variability across batches. At day 28 (D28), the GI-overall response rate (ORR) was 38% in the prospective population, including 5 complete responses (CR), 2 very good partial responses (VGPR) and 2 partial responses (PR). In the EAP, the GI-ORR was 58% (17 CR, 9 VGPR and 4PR). The 12-month overall survival (OS) was 25% in the prospective study and 38% in the EAP. Regarding safety, five infectious complications, including 3 sepsis, could not be excluded from being related to the study procedure in HERACLES. Shotgun sequencing analyses of the identified strains suggest that none were found in MaaT013. In the EAP, 18 pharmacovigilance cases were reported among 52 treated patients, including 11 bacteraemia/sepsis. In HERACLES, we observed in stools from responding patients at D28 a higher microbiota richness and increased levels of beneficial bacteria, in particular butyrate producers, along with increased levels of short-chain fatty acid and bile acids. In contrast, stools from non-responding (NR) patients displayed increased levels of pathogenic pro-inflammatory bacteria along with increased systemic inflammatory parameters. Overall, MaaT013 was safe in this population of highly immunocompromised patients and was associated with responses in some patients with GI-aGvHD and deserves further investigation. MaaT Pharma.

Clinical study of 19 cases of steroid-refractory gastrointestinal acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation with fecal microbiota transplantation

Objective: To investigate the clinical efficacy of fecal microbiota transplantation (FMT) for treating steroid-refractory gastrointestinal acute graft-versus-host disease (GI-aGVHD) . Methods: This analysis included 29 patients with hematology who developed steroid-refractory GI-aGVHD after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in Huaian Hospital Affiliated to Xuzhou Medical University from March 2017 to March 2022. Among them, 19 patients underwent FMT treatment (the FMT group) and 10 patients did not (the control group). The efficacy and safety of FMT were assessed, as well as the changes in intestinal microbiota abundance, lymphocyte subpopulation ratio, peripheral blood inflammatory cytokines, and GVHD biomarkers before and after FMT treatment. Results: ① Complete remission of clinical symptoms after FMT was achieved by 13 (68.4%) patients and 2 (20.0%) controls, with a statistically significant difference (P<0.05). Intestinal microbiota diversity increased and gradually recovered to normal levels after FMT and FMT-related infections did not occur. ②The proportion of CD3(+) and CD8(+) cells in the FMT group after treatment decreased compared with the control group, and the ratio of CD4(+), regulatory T cells (Treg), and CD4(+)/CD8(+) cells increased (all P< 0.05). The interleukin (IL) -6 concentration in the FMT group was lower than that in the control group [4.15 (1.91-5.71) ng/L vs 6.82 (2.40-8.91) ng/L, P=0.040], and the IL-10 concentration in the FMT group was higher than that in the control group [12.11 (5.69-20.36) ng/L vs 7.51 (4.10-9.58) ng/L, P=0.024]. Islet-derived protein 3α (REG3α) was significantly increased in patients with GI-aGVHD, and the REG3α level in the FMT group was lower than that in the control group after treatment [30.70 (10.50-105.00) μg/L vs 74.35 (33.50-139.50) μg/L, P=0.021]. Conclusion: FMT is a safe and effective method for the treatment of steroid-refractory GI-aGVHD by restoring intestinal microbiota diversity, regulating inflammatory cytokines, and upregulating Treg cells.

Multi-parametric MRI in the diagnosis and scoring of gastrointestinal acute graft-versus-host disease

ObjectivesAcute gastrointestinal graft-versus-host disease (GI-aGVHD) is a severe complication of allogeneic hematopoietic stem cell transplantation (HSCT). Diagnosis relies on clinical, endoscopic, and pathological investigations. Our purpose is to assess the value of magnetic resonance imaging (MRI) in the diagnosis, staging, and prediction of GI-aGVHD-related mortality.MethodsTwenty-one hematological patients who underwent MRI for clinical suspicion of acute GI-GVHD were retrospectively selected. Three independent radiologists, blinded to the clinical findings, reanalyzed MRI images. The GI tract was evaluated from stomach to rectum by analyzing fifteen MRI signs suggestive of intestinal and peritoneal inflammation. All selected patients underwent colonoscopy with biopsies. Disease severity was determined on the basis of clinical criteria, identifying 4 stages of increasing severity. Disease-related mortality was also assessed.ResultsThe diagnosis of GI-aGVHD was histologically confirmed with biopsy in 13 patients (61.9%). Using 6 major signs (diagnostic score), MRI showed 84.6% sensitivity and 100% specificity in identifying GI-aGVHD (AUC = 0.962; 95% confidence interval 0.891–1). The proximal, middle, and distal ileum were the segments most frequently affected by the disease (84.6%). Using all 15 signs of inflammation (severity score), MRI showed 100% sensitivity and 90% specificity for 1-month related mortality. No correlation with the clinical score was found.ConclusionMRI has proved to be an effective tool for diagnosing and scoring GI-aGVHD, with a high prognostic value. If larger studies will confirm these results, MRI could partly replace endoscopy, thus becoming the primary diagnostic tool for GI-aGVHD, being more complete, less invasive, and more easily repeatable.Key Points• We have developed a new promising MRI diagnostic score for GI-aGVHD with a sensitivity of 84.6% and specificity of 100%; results are to be confirmed by larger multicentric studies.• This MRI diagnostic score is based on the six MRI signs most frequently associated with GI-aGVHD: small-bowel inflammatory involvement, bowel wall stratification on T2-w images, wall stratification on post-contrast T1-w images, ascites, and edema of retroperitoneal fat and declivous soft tissues.• A broader MRI severity score based on 15 MRI signs showed no correlation with clinical staging but high prognostic value (100% sensitivity, 90% specificity for 1-month related mortality); these results also need to be confirmed by larger studies.