Risk Of aGVHD Research Articles

Ruxolitinib plus steroids for acute graft versus host disease: a multicenter, randomized, phase 3 trial

Newly diagnosed patients with high-risk acute graft-versus-host disease (aGVHD) often experience poor clinical outcomes and low complete remission rates. Ruxolitinib with corticosteroids showed promising efficacy in improving response and failure free survival in our phase I study. This study (ClinicalTrials.gov: NCT04061876) sought to evaluate the safety and effectiveness of combining ruxolitinib (RUX, 5 mg/day) with corticosteroids (1 mg/kg/day methylprednisolone, RUX/steroids combined group) versus using methylprednisolone alone (2 mg/kg/day, steroids-only group). Newly diagnosed patients with intermediate- or high-risk aGVHD were included, with risk levels classified by either the Minnesota aGVHD Risk Score or biomarker assessment. Patients were randomized in a ratio of 1:1 into 2 groups: 99 patients received RUX combined with methylprednisolone, while the other 99 received methylprednisolone alone as the initial treatment. The RUX/steroids group showed a significantly higher overall response rate (ORR) on day 28 (92.9%) compared to the steroids-only group (70.7%, Odds Ratio [OR] = 5.8; 95% Confidence Interval [CI], 2.4–14.0; P < 0.001). Similarly, the ORR on day 56 was higher in the RUX/steroids group (85.9% vs. 46.5%; OR = 7.07; 95% CI, 3.36–15.75; P < 0.001). Additionally, the 18-month failure-free survival was significantly better in the RUX/steroids group (57.2%) compared to the steroids-only group (33.3%; Hazard Ratio = 0.46; 95% CI, 0.31–0.68; P < 0.001). Adverse events (AEs) frequencies were comparable between both groups, with the exception of fewer grade 4 AEs in the RUX/steroids group (26.3% vs. 50.5% P = 0.005). To our knowledge, this study is the first prospective, randomized controlled trial to demonstrate that adding ruxolitinib to the standard methylprednisolone regimen provides an effective and safe first-line treatment for newly diagnosed high-risk acute GVHD.

Incidence, risk factors and therapy response of acute graft-versus-host disease after myeloablative hematopoietic stem cell transplantation with posttransplant cyclophosphamide.

Posttransplant cyclophosphamide, sirolimus and mycophenolate mofetil (PTCy/siro/MMF) constitutes an innovative and well-tolerated acute graft-versus-host disease (aGVHD) prophylaxis after allogeneic stem cell transplantation (allo-HSCT), but risk factors for aGVHD incidence and therapy failure in this setting are scarce. This study prospectively registered all consecutive adult patients with hematologic malignancies who received a myeloablative allo-HSCT using PTCy/siro/MMF prophylaxis at our institution between 2017 and 2023. A total of 385 patients were included, of whom 44%, 34% and 22% were transplanted from matched sibiling, matched unrelated and haploidentical donors, respectively. The 180-day cumulative incidence of aGVHD was 21% (95% confidence interval [CI] 17-25%) for grade II-IV and 11% (95% CI 8-14%) grade III-IV aGVHD. The use of haploidentical donors was associated with an increased risk of severe aGVHD. Among 75 patients receiving first-line systemic corticosteroids, 49% achieved a sustained complete response, while 23% and 24% developed steroid-dependent (SD-aGVHD) and steroid-refractory aGVHD (SR-aGVHD), respectively. SR-aGVHD was associated with worse salvage treatment response and overall survival compared to SD-aGVHD. The 1-year cumulative incidence of aGVHD-related mortality was 5.4% (95% CI, 3.3-8.1). Risk factors for aGVHD-related mortality included haploidentical donors, older donors, diagnosis of myeldysplastic neoplasms, and grade IV aGVHD. This study confirms a low incidence aGVHD with PTCy/siro/MMF prophylaxis. SR-aGVHD showed poorer response to salvage therapies and worse survival, while haploidentical donors and older donor age were negative predictors for aGVHD-related deaths.

Effect of donor and recipient HLA mismatched locus on the prognosis of childhood with leukemia after umbilical cord blood transplantation

Objective: The aim of the study was to investigate the impact of the sites of high-resolution human leukocyte antigen (HLA) mismatch on the prognosis of children with leukemia undergoing umbilical cord blood transplantation (UCBT). Methods: Clinical data and high-resolution HLA-A, HLA-B, HLA-C, HLA-DRB1 and HLA-DQB1 locus gene information were collected in the children who underwent the UCBT for the first time at Children's Hospital of Soochow University between January 2016 and June 2023. In each locus, according to whether the two genes were compatible, they were divided into a compatible group (two genes were perfectly matched) and a non-compatible group (one gene was not matched). In different loci, the differences in occurrence, recurrence, non-recurrence death and survival of acute graft versus host disease (aGVHD) were compared between the two groups. Multivariate Cox regression was employed to analyzed the influencing factors for overall survival rate, and Fine-Gray proportional hazards model was employed to analyze the influencing factors of other outcome events. Results: A total of 100 patients were enrolled (55 males and 45 females), whose age [M (Q1, Q3)] at the time of transplantation was 3.9 (2.0, 6.5) years. There were 55 cases in the HLA-A matched group and 45 cases in the mismatched group. The 5-year non-recurrence mortality (NRM) in the HLA-A matched group was lower than that in the mismatched group (P=0.024). The cumulative incidence of aGVHD within 100 days after transplantation in the HLA-A matched group was lower than that in the mismatched group (P=0.017), and there were no statistically significant differences in other outcome events between the groups (all P>0.05). There were 70 cases in the HLA-B matched group and 30 cases in the mismatched group. The 5-year cumulative recurrence rate in the HLA-B matched group was higher than that in the mismatched group (P=0.027). There were 79 cases in the HLA-C matched group and 21 cases in the mismatched group, and there were no statistically difference in the outcome events between the groups (P>0.05). There were 73 cases in HLA-DRB1 matched group and 27 cases in mismatched group. The 5-year overall survival rate in HLA-DRB1 matched group was higher than that in mismatched group (P=0.036), the 5-year cumulative recurrence rate in HLA-DRB1 matched group was higher than that in mismatched group (P=0.028), and the 5-year NRM in HLA-DRB1 matched group was lower than that in mismatched group (P=0.008). The cumulative incidence of aGVHD within 100 days after transplantation in the matched group was lower than that in the mismatched group (P=0.010), and and there were no statistically significant difference in other outcome events between the groups (P>0.05). There were 68 cases in HLA-DQB1 matched group and 32 cases in mismatched group. There was no statistical difference in outcome events between the two groups (all P>0.05). The risk of aGVHD in HLA-A mismatched group was higher than that in HLA-A matched group (HR=1.25, 95%CI: 1.12-1.38). The risk of recurrence in HLA-B mismatched group was lower than that in HLA-B matched group (HR=0.77, 95%CI: 0.63-0.91). Mismatched group at HLA-DRB1 compared with matched group at HLA-DRB1, had a higher risk of aGVHD (HR=1.37, 95%CI: 1.26-1.48), a higher risk of non-recurrence death (HR=1.39, 95%CI: 1.28-1.50), and a higher risk of death (HR=1.27, 95%CI: 1.18-1.36). No association was found between HLA-C and HLA-DQB1 locus with the risk of aGVHD, recurrence, non-recurrence death, and survival (all P>0.05). Conclusions: In UCBT, the risk of aGVHD in children with matching HLA-A sites of donor and recipient is lower than that in children with incompatible HLA-A sites. Compared with children with incompatible HLA-DRB1 sites, children with HLA-DRB1 matched sites has a lower risk of acute GVHD, a lower 5-year NRM, and a higher risk of death. The recurrence rate of children with matching HLA-B loci is higher than that of children without matching HLA-B loci.

The impact of the donors' COVID-19 status on the outcomes of allogeneic hematopoietic stem cell transplantation: a multi-center retrospective study.

To explore the impact of donors' COVID-19 status on allogeneic stem cell transplantation (allo-HSCT), we compared the transplant outcomes of 74 participants. This multi-center retrospective study included nine participants receiving grafts from COVID-19 positive donors (CPD), 45 from COVID-19 experienced donors (CED), and 20 from COVID-19 naive donors (CND). We evaluated engraftment, complications, and survival rates among the three groups. All apheresis procedures were successful with no significant differences in CD34+ cells or lymphocytes in grafts among the three groups. All patients achieved engraftment by day 30 post-HSCT. The incidence of grade II-IV acute graft-versus-host disease (aGVHD) was 55.6%, 20%, and 10% in the CPD, CED, and CND groups, respectively (p = 0.024). Multivariate analysis indicated that COVID-19 positivity in donors at the time of apheresis was an independent risk factor for II-IV aGVHD (p = 0.020, OR = 12.159, 95% CI 1.783 -135.760). No differences were observed among the groups in terms of chronic GVHD, viral infection, or sinusoidal obstruction syndrome. The 6-month overall survival and disease-free survival rates were also similar among the three groups. Our results suggest that the COVID-19-positive status of donors might not impact graft collection, engraftment, or short-term survival of allo-HSCT recipients but might increase the risk of aGVHD. Further research is needed to explore the influence of donors' COVID-19 status on long-term complications and survival in allo-HSCT recipients.

Ruxolitinib Plus Basiliximab Therapy for Steroid-Refractory Acute Graft-Versus-Host Disease in Unrelated Cord Blood Transplantation: A Large-Scale Study

Steroid-refractory (SR) acute graft-versus-host disease (aGVHD) is a major cause of mortality after allogeneic hematopoietic stem cell transplantation. We aimed to evaluate the effectiveness and safety of ruxolitinib plus basiliximab for treating SR-aGVHD after unrelated cord blood transplantation (UCBT). Among the 1154 patients with hematological malignancies who underwent UCBT between February 2014 and May 2022, 198 patients with grade II to IV SR-aGVHD were enrolled, 112 of whom were treated with basiliximab alone (basiliximab group) and 86 of whom received basiliximab plus ruxolitinib (combined therapy group). The combined therapy group demonstrated a significantly higher complete response rate (CRR) on day 28 (36.0%) than did the basiliximab group (12.5%, P < .001). SR-aGVHD patients were further stratified into standard-risk and high-risk groups using the refined Minnesota aGVHD risk score. For standard-risk patients, combined therapy significantly improved the CRR (51.1% versus 13.6%, P < .001) and 3-year overall survival (74.5% versus 52.4%, P = .033). However, high-risk patients did not exhibit the same benefits. Compared with basiliximab monotherapy, ruxolitinib plus basiliximab therapy was an effective therapy for patients with standard-risk SR-aGVHD following UCBT. The effectiveness of combined therapy in high-risk patients was not apparent, indicating the need for other treatments.

Recent infection with SARS-CoV-2 in donors was associated with a higher incidence of acute graft-versus-host disease in recipients undergoing allogeneic haematopoietic stem cell transplantation.

The global pandemic has resulted in the common occurrence of SARS-CoV-2 infection in the population. In the post-pandemic era, it is imperative to understand the influence of donor SARS-CoV-2 infection on outcomes after allogeneic haematopoietic stem cell transplantation (allo-HSCT). We retrospectively analysed allo-HSCTs from donors with mild SARS-CoV-2 infection or early recovery stage (ERS) (group 1, n = 65) and late recovery stage (group 2, n = 120). Additionally, we included allo-HSCT from donors without prior SARS-CoV-2 infection as group 0 (n = 194). Transplants from donors with different SARS-CoV-2 infection status had comparable primary engraftment and survival rates. However, group 1 had higher incidences of acute graft-versus-host disease (aGvHD), grade II-IV (41.5% vs. 28.1% in group 0 [p = 0.014] and 30.6% in group 2 [p = 0.067]) and grade III-IV (22.2% vs. 9.6% [p = 0.004] in group 0 and 12.2% in group 2 [p = 0.049]). Conversely, the risk of aGvHD in group 2 was similar to that in group 0 (p > 0.5). Multivariable analysis identified group 1 associated with grade II-IV (hazard ratio [HR] 2.307, p = 0.010) and grade III-IV (HR 2.962, p = 0.001) aGvHD, which yielded no significant risk factors for survival. In conclusion, we preliminarily demonstrated donors in the active infection state or ERS of mild SARS-CoV-2 infection were associated with higher incidences of aGvHD in transplants from related donors.

Multi-omics analysis of a fecal microbiota transplantation trial identifies novel aspects of acute graft-versus-host disease pathogenesis.

Acute graft-versus-host disease (aGVHD) is a major complication of allogeneic hematopoietic cell transplantation (alloHCT) associated with gut microbiota disruptions. However, whether therapeutic microbiota modulation prevents aGVHD is unknown. We conducted a randomized, placebo-controlled trial of third-party fecal microbiota transplantation (FMT) administered at the peak of microbiota injury in 100 patients with acute myeloid leukemia receiving induction chemotherapy and alloHCT recipients. Despite improvements in microbiome diversity, expansion of commensals, and shrinkage of potential pathogens, aGVHD occurred more frequently after FMT than placebo. Although this unexpected finding could be explained by clinical differences between the two arms, we asked whether a microbiota explanation might be also present. To this end, we performed multi-omics analysis of pre- and post-intervention gut microbiome and serum metabolome. We found that post-intervention expansion of Faecalibacterium, a commensal genus with gut-protective and anti-inflammatory properties under homeostatic conditions, predicted a higher risk for aGVHD. Faecalibacterium expansion occurred predominantly after FMT and was due to engraftment of unique donor taxa, suggesting that donor Faecalibacterium-derived antigens might have stimulated allogeneic immune cells. Faecalibacterium and ursodeoxycholic acid (an anti-inflammatory secondary bile acid) were negatively correlated, offering an alternative mechanistic explanation. In conclusion, we demonstrate context dependence of microbiota effects where a normally beneficial bacteria may become detrimental in disease. While FMT is a broad, community-level intervention, it may need precision engineering in ecologically complex settings where multiple perturbations (e.g. antibiotics, intestinal damage, alloimmunity) are concurrently in effect.

Effect of CD8+ CD28- T Cells on Acute Graft-Versus-Host Disease after Haploidentical Hematopoietic Stem Cell Transplantation

To investigate the effect of CD8+ CD28- T cells on acute graft-versus-host disease(aGVHD) after haploidentical hematopoietic stem cell transplantation(haplo-HSCT). The relationship between absolute count of CD8+ CD28- T cells and aGVHD in 60 patients with malignant hematological diseases was retrospectively analyzed after haplo-HSCT, and the differences in the incidence rate of chronic graft-versus host disease(cGVHD), infection and prognosis between different CD8+ CD28- T absolute cells count groups were compared. aGVHD occurred in 40 of 60 patients after haplo-HSCT, with an incidence rate of 66.67%. The median occurrence time of aGVHD was 32.5(20-100) days. At 30 days after the transplantation, the absolute count of CD8+ CD28- T cells of aGVHD group was significantly lower than that of non-aGVHD group (P =0.03). Thus the absolute count of CD8+ CD28- T cells at 30 days after transplantation can be used to predict the occurrence of aGVHD to some extent. At 30 days after transplantation, the incidence rate of aGVHD in the low cell count group (CD8+ CD28- T cells absolute count < 0.06/μl) was significantly higher than that in the high cell count group (CD8+ CD28- T cells absolute count ≥0.06/μl,P =0.011). Multivariate Cox regression analysis further confirmed that the absolute count of CD8+ CD28-T cells at 30 days after transplantation was an independent risk factor for aGVHD, and the risk of aGVHD in the low cell count group was 2.222 times higher than that in the high cell count group (P =0.015). The incidence of cGVHD, fungal infection, EBV infection and CMV infection were not significantly different between the two groups with different CD8+ CD28- T cells absolute count. The overall survival, non-recurrent mortality and relapse rates were not significantly different between different CD8+ CD28- T cells absolute count groups. Patients with delayed CD8+ CD28- T cells reconstitution after haplo-HSCT are more likely to develop aGVHD, and the absolute count of CD8+ CD28- T cells can be used to predict the incidence of aGVHD to some extent. The absolute count of CD8+ CD28- T cells after haplo-HSCT was not associated with cGVHD, fungal infection, EBV infection, and CMV infection, and was also not significantly associated with the prognosis after transplantation.

Biomarkers in a phase 1b study of investigational microbiome therapeutic SER-155 in adults undergoing allogeneic hematopoietic cell transplantation (allo-HCT).

6554 Background: Acute graft- versus-host disease (aGvHD) is a life-threatening complication following allo-HCT. Microbiome dysfunction and associated GI barrier disruption may contribute to aGvHD via activation of inflammatory immune responses. Circulating biomarkers in the peri-transplant period are correlated with risk of severe aGvHD, including suppression of tumorigenicity 2 (ST2), regenerating islet-derived 3-alpha (Reg3a) and inflammatory cytokines (IL6, IFNϒγ &amp; TNFα). SER-155 is an investigational cultivated oral microbiome therapeutic designed to restructure the GI microbiome, improve GI barrier integrity and reduce GI inflammation and is being assessed in a 2-part Phase 1b study in adults undergoing allo-HCT. We present preliminary safety, GvHD, PK, and exploratory biomarker data from the completed open-label Cohort 1 through Day 100 post-HCT. Methods: Adult recipients of allo-HCT were eligible. HCT conditioning and aGvHD prophylaxis were per investigator discretion. Patients received 2 courses of SER-155 (pre-HCT and post-neutrophil engraftment, each comprised of 4 days of microbiome conditioning with oral vancomycin followed by 10 days oral SER-155. The primary endpoint was safety. Strain engraftment (PK) and biomarkers were assessed in stool and plasma samples. Results: Fifteen adults enrolled; 13 received at least 1 course of study drug (median age 67; 54% male), and 11 underwent allo-HCT. Following each course, the majority of the 16 SER-155 strains were detected in stool. Treatment-emergent adverse events (AEs) were reported in all patients with GI AEs the most common. No serious AEs (SAEs) were deemed related to SER-155. Most SAEs and AEs of special interest (ie, BSIs, invasive or GI infections) occurred between HCT and the 2nd SER-155 course. There were no deaths before Day 100. No BSIs were attributable to SER-155 strains. The rate of grade 2-4 aGvHD based on MAGIC criteria through Day 100 was 45.5%; no severe grade 3-4 aGvHD was observed. Median levels of plasma biomarkers REG3α, ST2 and inflammatory cytokines were not elevated relative to a reference range (Table). Conclusions: In this small open-label cohort, SER-155 was generally well-tolerated through Day 100 without drug-related SAEs and no severe aGvHD. Plasma biomarkers were not elevated at HCT Day 0 or neutrophil recovery. These preliminary observations align with the design and preclinical evaluation of SER-155. Clinical trial information: NCT04995653 . [Table: see text]

Risk prediction and function evaluation by T-cell epitope model and expression model of HLA-DPB1 mismatching in unrelated-donor hematopoietic stem cell transplantations

Objective: To evaluate the risk prediction and assessment function of HLA-DPB1 T-cell epitope (TCE) model and expression model in human leukocyte antigen (HLA)-matched unrelated hematopoietic stem cell transplantation (MUD-HSCT) with HLA-DPB1 mismatching. Methods: A total of 364 (182 pairs) potential MUD-HSCT donors and recipients confirmed by HLA high-resolution typing in Shaanxi Blood Center from 2016 to 2019 were analyzed retrospectively. Of the 182 recipients, there were 121 males and 61 females with an average age of (26.3±14.2) years. Of the 182 donors, there were 148 males and 34 females with an average age of (33.7±7.5) years. Polymerase chain reaction-sequence-based typing (PCR-SBT), next-generation sequencing (NGS) and polymerase chain reaction-sequence specific oligonucleotide probe (PCR-SSO) based on LABScan®3D platform were used for high-resolution typing of HLA-A, B, C, DRB1, DQB1, DPB1 gene, and PCR-SBT was used for single nucleotide polymorphism (SNP) typing. TCE model and expression model were used to predict and evaluate the HLA-DPB1 mismatch pattern and acute graft-versus-host-disease (aGVHD) risk. Results: A total of 26 HLA-DPB1 alleles and their 3'-UTR rs9277534 SNP genotypes were detected in this study population, and two new alleles HLA-DPB1*1052∶01 and HLA-DPB1*1119∶01 were found and officially named. The overall mismatch rate of HLA-DPB1 in MUD-HSCT donors and recipients was 90.66% (165/182). In TCE model, the HLA-DPB1 mismatch rates of permissible mismatch (PM) and non-permissible mismatch (non-PM) were 47.80% (87/182) and 42.86% (78/182), respectively. The non-PM in GvH direction was 13.73% (25/182), and which in HvG direction was 29.12% (53/182). A total of 73 pairs of donors and recipients in TCE model met the evaluation criteria of expression model. Among of TCE PM group, recipient DP5 mismatches accounted for 34.25% (25/73) were predicted as aGVHD high risk according to expression model. For the TCE non-PM group, both the recipient DP2 mismatches of 6.85% (5/73) and recipient DP5 mismatches of 10.86% (8/73) were predicted to be at high risk for aGVHD. Risk prediction by TCE model and expression model was 27.27% concordant and 16.97% unconcordant. Conclusions: TCE model and expression model are effective tools to predict aGVHD risk of MUD-HSCT. Comprehensive application of the two models is helpful to the hierarchical assessment of HSCT risk.

Matched unrelated donor transplantation versus haploidentical transplantation with post-transplant cyclophosphamide in children with acute myeloid leukemia: a PDWP-EBMT study.

In children with acute myeloid leukemia (AML) who lack a human leukocyte antigen (HLA) identical sibling, the donor can be replaced with an HLA-matched unrelated donor (MUD) or a haploidentical donor (haplo). We compared outcomes of patients <18 years with AML in first and second complete remission (CR1 and CR2) undergoing a hematopoietic stem cell transplantation (HCT) either with a MUD with anti-thymocyte globulin (ATG) (N=420) or a haplo HCT with post-transplant cyclophosphamide (PT-CY) (N=96) after a myeloablative conditioning regimen (MAC) between 2011 and 2021, reported to the European Society for Blood and Marrow Transplantation. A matched pair analysis was performed to adjust for differences among groups. The final analysis was performed on 253 MUD and 95 haplo-HCT. In the matched cohort, median age at HCT was 11.2 and 10 years and median year of HCT was 2017 and 2018, in MUD and haplo-HCT recipients, respectively. The risk of grade III-IV acute graft-versus-host disease (aGVHD) was significantly higher in the haplo group (hazard ratio [HR]=2.33, 95% confidence interval [CI]: 1.18-4.58; P=0.01). No significant differences were found in 2 years overall survival (OS; 78.4% vs. 71.5%; HR=1.39, 95% CI: 0.84-2.31; P=0.19), leukemia-free survival (LFS; 72.7% vs. 69.5%; HR=1.22, 95% CI: 0.76-1.95; P=0.41), CI of relapse (RI; 19.3% vs. 19.5%; HR=1.14, 95% CI: 0.62-2.08; P=0.68) non-relapse-mortality (NRM; 8% vs. 11%; HR=1.39, 95% CI: 0.66-2.93; P=0.39) and graft-versus-host free relapse-free survival (GRFS; 60.7% vs. 54.5%, HR=1.38, 95% CI: 0.95-2.02; P=0.09) after MUD and haplo-HCT respectively. Our study suggests that haplo-HCT with PT-CY is a suitable option to transplant children with AML lacking a matched related donor.

Longitudinal dynamics of gut microbiota in the pathogenesis of acute graft-versus-host disease.

The gut microbiota has been reported to be associated with acute graft-versus-host disease (aGvHD) in hematopoietic stem cell transplantation (HSCT). Dynamic surveillance of the microbiota is required to understand the detailed pathogenesis involved in the process of aGvHD. Fecal samples were collected prospectively at four timepoints, including pre-HSCT (T1), graft infusion (T2), neutrophil engraftment (T3), and 30 days after transplantation (T4). Fecal samples were profiled by 16S ribosomal RNA gene sequencing to assess the microbiota composition. From the T1 to T4 timepoint, the diversity of the gut microbiota decreased, and the dominant species also changed, with a decrease in the obligate anaerobic bacteria and a shift toward a "pathogenic community". Compared with non-aGvHD patients, aGvHD patients had a lower abundance of Roseburia at T1 and a higher abundance of Acinetobacter johnsonii at T2. Furthermore, Acinetobacter johnsonii was negatively correlated with the secretion of IL-4 and TNF-α. At T3, Rothia mucilaginos was demonstrated to be linked with a decreased risk of aGvHD, which was accompanied by decreased secretion of IL-8. At T4, higher abundances of Lactobacillus paracasei and Acinetobacter johnsonii were identified to be related with aGvHD. Lactobacillus paracasei was associated with the downregulation of IL-10, and Acinetobacter johnsonii was associated with the downregulation of IL-2 and TNF-α. Dynamic changes in gut microbiota composition and related cytokines were found to be related to aGvHD, including pathogenic or protective changes. These findings suggested that manipulation of gut microbiota at different timepoints might be a promising avenue for preventing or treating this common complication.

Recombinant Human Thrombopoietin Reduces the Risk of Acute Graft-Versus-Host-Disease and Its Mechanisms

Objective: Acute graft-versus-host-disease (aGVHD) is an important complication that is observed after allogeneic hematopoietic stem cell transplantation (allo-HSCT). We aimed to evaluate the effects of recombinant human thrombopoietin (TPO; rhTPO) on aGVHD using clinical data, mice models, and peripheral blood mononuclear cells (PBMCs). Methods: From 2016 to 2018, 162 cases of allo-HSCT in our hospital were recruited in this study. The correlation between TPO use and aGVHD was analyzed. After a GVHD model was constructed in Balb-C mice, HE staining was performed to compare the pathophysiological changes of the liver, intestine, lung, kidney, and other organs of the mice. The levels of lymphocyte subsets and cytokines in the mice spleens in the different groups were detected. PBMCs were isolated from the peripheral blood of healthy persons and patients with allo-HSCT via Ficoll gradient centrifugation and treated with different concentrations of rhTPO. The proliferation of PBMCs was detected via the CCK8 method, and the differentiation of PBMCs into lymphocytes was analyzed via flow cytometry. Results: 1) The occurrence of aGVHD was observed in 10 patients (47.6%) in the control group and 27 (23.1%) in the treatment group. The difference between the two groups was statistically significant (χ2=5.465, P=0.019). 2) The results of the aGVHD mice proved that rhTPO decreased the damage to the mouse liver, intestine, lung, and kidney tissues. In addition, splenic cell subpopulations CD4+cells, CD8+cells, T cells, and NK cells increased in the GVHD group but decreased due to rhTPO (P&amp;lt;0.05). After rhTPO treament, T cell subpopulations Th2 and Th17 cells decreased in the GVHD mice (P&amp;lt;0.05). Cytokines CD8+IL-17A+ and CD8+IL-4+IFNγ showed no difference between the four groups (P&amp;gt;0.05). Compared to GVHD mice, CD8+IL-4+ decreased in TPO-treated GVHD mice, and the effect of TPO at a high dose was more significant (P&amp;lt;0.05). 3) The results of the PMBCs suggested that a low dose of rhTPO could promote the proliferation of PMBCs, while a high dose could inhibit the proliferation. rhTPO promoted the differentiation of PBMCs into the CD3-PC5 subset. Conclusions: Altogether, this study indicates that rhTPO reduces the risk of aGVHD and is a protective factor against the occurrence of aGVHD.

Risk Factors and Prognostic Model for II-IV aGVHD in Patients with Engraftment Syndrome after Haploidentical Hematopoietic Stem Cell Transplantation

Background Engraftment syndrome (ES), characterized by noninfective fever, rash, noncardiogenic pulmonary edema, hepatic dysfunction and weight gain, is a common complication after haplo-HSCT. Although ES has been reported in the previous literature, there is still no consensus on the risk factors, outcomes and treatment of ES, as there is not only a lack of uniformity described by authors but also conflicting evidence between studies. One meta-analysis found that patients with ES have significantly higher odds of developing aGVHD than patients without ES. However, a strategy for identifying high-risk patients with ES for aGVHD remains unclear although important for early aGVHD prevention and the improvement of patient outcomes. Here, we retrospectively analyzed a large cohort of posthaplo-HSCT ES patients and described the risk factors, outcomes and prognostic model for II-IV aGVHD in patients with ES. Methods A total of 384 patients with ES after haplo-HSCT at Peking University People's Hospital between 2013 and 2022 were retrospectively identified. We first performed a nested case‒control study to identify the risk factors for ES, and three controls were randomly selected for each case according to the time of transplant and the length of follow-up. The cohort of ES patients was further divided into a derivation cohort of 258 patients and a validation cohort of 126 patients. We used a logistic regression model to perform univariate and multivariate analyses to determine the risk factors and prognostic factors for II-IV aGVHD in patients with ES after haplo-HSCT. The prognostic model performance was assessed by evaluating the discrimination [area under the curve (AUC)], calibration (calibration plot), and net benefit [decision curve analysis (DCA)]. Results In 384 patients diagnosed with ES after haplo-HSCT, the median diagnostic time of ES was 11 days after haplo-HSCT, close to the time of neutrophil engraftment. Among them, 252 (65.6%) patients developed aGVHD, and 123 (32.0%) suffered II-IV aGVHD. The 3-year survival rate of ES patients who developed II-IV aGVHD was 17.1% (21/123) compared with 4.3% (11/252) in those without II-IV aGVHD (p&amp;lt;.001).Through multivariable logistic binary regression models, six prognosis risk factors were selected，including age at HSCT≤25 years(p=0.008; odds ratio [OR], 4.47; 95% confidence interval [CI], 1.54-14.30), obesity (BMI≥28) at HSCT(p=0.039; OR, 12.60; 95% CI, 1.30-194.14), previous pregnancy history (p=0.09; OR, 3.42; 95% CI, 0.83-18.45), time from diagnosis to transplantation≥6 months (p=0.027; OR, 2.73; 95% CI, 0.97-8.50), a high dose of MNC administration (≥9×10 8)(p=0.003; OR, 4.39; 95% CI, 1.70-12.41) and a high dose platelet transfusion (≥2u) during conditioning regimen (p=0.007; OR, 4.04; 95% CI, 1.51-11.73). According to the regression coefficient, 2 scores were assigned for obesity at HSCT, and 1 score was assigned for the other risk factors. Hence, a prognostic model for II-IV aGVHD termed TOPMAP ( time from diagnosis to transplantation, obesity, previous pregnancy history, high-dose MNC administration, age, and high-dose platelet transfusion) was constructed. Patients were stratified into 3 risk groups: low risk (0-2), intermediate risk (3-4), and high risk (5-7), which showed an incidence of II-IV aGVHD of 15.9% for low risk, 39.2% for intermediate risk, and 83.3% for high risk (P&amp;lt;0.001). The AUCs of the prognostic scoring model were 0.816 (95% CI 0.727-0.903) and 0.813 (0.759-0.868) for the internal validation and validation cohorts, respectively. The calibration plots showed a high agreement between the predicted and observed outcomes. Decision curve analysis indicated that patients with engraftment syndrome could benefit from the clinical application of the prognostic model. Conclusion Here, we reported the largest study on ES posthaplo-HSCT and found risk factors for ES onset. We developed the first straightforward scoring model (designated TOPMAP) that incorporates clinical and laboratory risk factors to predict the high-risk group for II-IV aGVHD in patients with ES after haplo-HSCT. This model can effectively help clinicians identify ES patients early, sectionalize them according to risk for II-IV aGVHD, carry out aGVHD prevention and improve patient outcomes.

Artificial Intelligence (AI) Based, Machine Learning (ML) Predicting the Individual Absolute Risk of Acute Graft Versus Host Disease (aGvHD) in a Retrospective International Cohort

Background: HSCT still holds potentially lethal complications such as aGvHD, relapse of malignant disease, graft rejection, and infections. 30 to 50% of all patients undergoing HSCT will develop aGvHD, causing high morbidity and mortality (grade 4 GvHD up to 90%) as well as generating significantly higher treatment costs than a HSCT without aGvHD. MatchGraft.AI is an AI based ML algorithm that predicts individual, absolute risk of aGvHD for every individual HSCT donor-recipient pair, based on data available prior to start of conditioning aiming for optimization of donor selection. Methods: MatchGraft.AI has been built in accordance with best clinical practice (Higgins et al 2021). A random forest is used to predict the probability of aGvHD free survival, GvHD free death and aGvHD. Missing data are imputed, except for the gradient boosted tree, by using the most frequent category for categorical variables and mean value for continuous variables. The performance characteristics are calculated in an aGvHD vs Rest (death or aGvHD free survival) fashion. The data is split into a stratified training and validation set with a ratio of 80% / 20%. Results: The model was trained at Charité University against a retrospective, multi center data set of 1035 German and north American patient/donor sets. We collected 1719 data sets. 684 cases were excluded due to mayor outcome parameters not being available. The following analyzation focuses on the 1035 included stem cell transplantation patient/donor sets (828 training set/ 207 validation set), 356 pediatric patients, 679 adults. M:F = 1,5; age 0 - 76 (median: 39.5 +/- 24.3 years). Indications for transplantation were malignant diseases (hematological neoplasms, lymphomas, solid tumors) in 731 patients and benign diseases (hemoglobinopathies, immune deficiencies, bone marrow failure) in 205 cases, in 99 cases diagnosis was not documented. Transplantations were performed between January 2013 and December 2019. Despite some missing data in our retrospective cohort, model performance was estimated at 0.70 AUC (fig.1). Integrated calibration index was 0,0277. Discussion: MatchGraft.AI predicts the risk of acute GvHD. By providing precise prediction of relevant complications, we expect the pool of possible donors to become larger as well as donor selection to improve. Furthermore, physicians and patients will be able to better prepare and adapt conditioning and treatment plans with MatchGraft.AI predictions. Conclusions: The prediction of individual aGvHD risk, using this AI ML model, is feasible and well calibrated, especially in the medium risk area. Ongoing continuous training, testing and adapting on additional international, multicenter retrospective and prospective data will further improve performance in the low risk area. This study is the basis for further prospective research.

Graft Versus Host Disease Prophylaxis with Tacrolimus, Sirolimus and MMF in Patients Undergoing Reduced Intensity Conditioning Allogeneic Transplantation

I ntroduction GvHD remains the leading cause of toxic morbidity and mortality (NRM) after allo-HSCT. Different prophylaxis schemes have been developed in the context of reduced intensity conditioning (RIC). In 2019, the multicenter phase 3 trial NCT01231412 compared GvHD prophylaxis based on the calcineurin inhibitor (CNI) CSA plus MMF with (experimental arm) or without (control arm) sirolimus. The triple combination was associated with a lower risk of aGvHD and longer survival and, in the authors' opinion, could constitute a new standard (Sandmaier, Lancet Oncol 2019). We present the largest real-world experience to date with the triple prophylaxis scheme in the context of allo-HSCT with RIC from matched-related (MRD), matched-unrelated (MUD) and mismatched URD (mmURD). Material and Methods Prospective study of 159 consecutive patients receiving an allo-HSCT after RIC between 09/2019 and 12/2022 at two centers using the tacro/siro/MMF as GvHD prophylaxis. The primary endpoint was the cumulative incidence of aGvHD grades 2-4. As secondary variables: cGvHD at 1 and 3 years, NRM at +100, +1 year and overall NRM, OS at 1 and 3 years, PFS at 1 and 3 years and GRFS at 1 and 3 years. Results Baseline characteristics are shown in Table 1. Note the high percentage of patients with high/very high rDRI or HCT-CI of 3+. In 38.4% an URD was used as source of progenitor cells and in 20.8% it was a MMURD. The median follow-up was 20 months (3-40). There were 4 (2.5%) graft failures (2 of them secondary). Median neutrophil and platelet engraftment was 16 days (3-175) and 12 days (7-210). The risk of relapse was 31% and 35% at 1 and 3 years. NRM at day +100, + 1 year and overall NRM was 4.4%, 8.17% and 9.4%. The causes of NRM were GvHD +/- infection in 73%, with other causes being TMA (n=1) and SOS (n=1). The cumulative incidence (CI) of grades 2-4 aGvHD 2-4 at day +100 and +180 was 29.7% and 32.3%, including 40% of upper gastrointestinal tract involvement which resolved with topical treatment. The CI of grades 3-4 aGvHD at day +100 and +180 was 12.8% and 16% (3.14% grade 4). The CI of cGvHD at 1 and 3 years was 21.5% and 51.2% and for moderate/severe it was 13.9% and 36.6%. OS at 1 and 3 years was 70.3% and 61%. Median PFS was 35 months, with 1- and 3-year PFS of 60% and 49%. The GRFS at 1 and 3 years was 44% and 32%. The risk of grades 2-4 aGvHD was significantly higher among patients receiving allo-HSCT from MMURD (at d+100 and +180, 35.4% and 39.9%) vs matched donors (at d+100 and +180, 55.5% and 61%, p=0.04). The same variable also influenced on OS (at 1 and 3 years 73.3% vs 64.6% and 57.6% vs 37.8% for matched vs mismatched donors, respectively; p=0.013) (Figure 1). On the other hand, low and intermediate DRI patients had a significantly better OS as compared to high/very high rDRI patients (at 1 and 3 years 80.8% and 80.8% for low vs 86.7% and 78.3% for intermediate vs 56.9% and 55.1% for high and very high; p=0.013) (Figure 1). Conclusions Triple prophylaxis with Tacro-Siro-MMF shows excelent results in terms of NRM, GvHD and survival in a high-risk and elderly population in the context of allo-HSCT from matched-related (MRD) and matched-unrelated (MUD) donors. The subgroup of patients receiving allo-HSCT from MMURD showed a high incidence of overall and grade 3-4 aGvHD with impact on OS, being a group that will probably benefit from other prophylaxis strategies.

Impact of Donor Statin Treatment on Graft-versus-Host Disease after Allogeneic Hematopoietic Cell Transplantation

Some retrospective studies have suggested that long-term donor statin use may protect against graft-versus-host disease (GVHD) in patients receiving cyclosporine (CSP)-based immunosuppression after allogeneic hematopoietic cell transplantation (HCT), but prospective studies of short-term treatment of donors with statin have shown conflicting results. We conducted 2 consecutive prospective clinical trials to assess whether donor statin treatment was associated with protection against severe acute GVHD (aGVHD). In a single-arm phase II trial (study 1), we evaluated whether short-term statin treatment of HLA-matched related donors for 14 days before HCT prevented grade III-IV aGVHD. In a prospective observational cohort study (study 2), we evaluated whether longer-term (>14 days) donor statin use was required for GVHD-protective effects. Study 1 was terminated after 6 of the 35 recipients (17%) developed grade III-IV GVHD. For study 2, we identified 135 patients whose unrelated donors had received long-term treatment with statins up to the time of HCT and 4942 patients whose donors had not received long-term statin treatment. The adjusted odds ratio for grade III-IV aGVHD (statin versus no statin) was .83 (95% confidence interval [CI], .46 to 1.50; P=.54). Multivariable analysis showed no statistically significant differences between the 2 groups in the risk of grade II-IV aGVHD, chronic GVHD, nonrelapse mortality, recurrent malignancy, or overall mortality. Among patients receiving CSP-based immunosuppression, including 35 with donors receiving long-term statin treatment and 973 with donors who did not receive statins, the adjusted odds ratio of grade III-IV aGVHD was .30 (95% CI, .07 to 1.35; P=.12). In study 1, short-term statin treatment of donors was ineffective in preventing grade III-IV GVHD. In study 2, in the prespecified subgroup of recipients given CSP-based immunosuppression, nondefinitive evidence suggested that donor statin use was associated with a reduced risk of severe aGVHD.

Pilot Study of Donor-Engrafted Clonal Hematopoiesis Evolution and Clinical Outcomes in Allogeneic Hematopoietic Cell Transplantation Recipients Using a National Registry

Improved treatment options, such as reduced-intensity conditioning (RIC), enable older patients to receive potentially curative allogeneic hematopoietic cell transplantation (HCT). This progress has led to increased use of older HLA-matched sibling donors. An unintended potential risk associated with older donors is transplantation of donor cells with clonal hematopoiesis (CH) into patients. We aimed to determine the prevalence of CH in older HLA-matched sibling donors pretransplantation and to assess the clinical impact of donor-engrafted CH on HCT outcomes. This was an observational study using donor peripheral blood samples from the Center for International Blood and Marrow Transplant Research repository, linked with corresponding recipient outcomes. To explore engraftment efficiency and evolution of CH mutations following HCT, recipient follow-up samples available through the Bone Marrow Transplant Clinical Trials Network (Protocol 1202) were included. Older donors and patients (both ≥55 years) receiving first RIC HCT for myeloid malignancies were eligible. DNA from archived donor blood samples was used for targeted deep sequencing to identify CH. The associations between donor CH status and recipient outcomes, including acute graft-versus-host disease (aGVHD), chronic GVHD (cGVHD), overall survival, relapse, nonrelapse mortality, disease-free survival, composite GVHD-free and relapse-free survival, and cGVHD-free and relapse-free survival, were analyzed. A total of 299 donors were successfully sequenced to detect CH. At a variant allele frequency (VAF) ≥2%, there were 44 CH mutations in 13.7% (41 of 299) of HLA-matched sibling donors. CH mostly involved DNMT3A (n=27; 61.4%) and TET2 (n= 9; 20.5%). Post-HCT samples from 13 recipients were also sequenced, of whom 7 had CH+ donors. All of the donor CH mutations (n=7/7; 100%) were detected in recipients at day 56 or day 90 post-HCT. Overall, mutation VAFs remained relatively constant up to day 90 post-HCT (median change, .005; range, -.008 to .024). Doubling time analysis of recipient day 56 and day 90 data showed that donor-engrafted CH mutations initially expand then decrease to a stable VAF; germline mutations had longer doubling times than CH mutations. The cumulative incidence of grade II-IV aGVHD at day 100 was higher in HCT recipients with CH+ donors (37.5% versus 25.1%); however, the risk for aGVHD by donor CH status did not reach statistical significance (hazard ratio, 1.35; 95% confidence interval, .61 to 3.01; P=.47). There were no statistically significant differences in the cumulative incidence of cGVHD or any secondary outcomes by donor CH status. In subset analysis, the incidence of cGVHD was lower in recipients of grafts from DNMT3A CH+ donors versus donors without DNMT3A CH (34.4% versus 57%; P=.035). Donor cell leukemia was not reported in any donor-recipient pairs. CH in older HLA-matched sibling donors is relatively common and successfully engrafts and persists in recipients. In a homogenous population (myeloid malignancies, older donors and recipients, RICr, non-cyclophosphamide-containing GVHD prophylaxis), we did not detect a difference in cGVHD risk or other secondary outcomes by donor CH status. Subgroup analyses suggest potential differential effects by clinical characteristics and CH mutations. Larger prospective studies are needed to robustly determine which subsets of patients and CH mutations elicit meaningful impacts on clinical outcomes.

Impact of the Recipient's Pre-Treatment Blood Lymphocyte Count on Intended and Unintended Effects of Anti-T-Lymphocyte Globulin in Allogeneic Hematopoietic Stem Cell Transplantation.

Background: In allogeneic hematopoietic stem cell transplantation (HSCT), Anti-T-Lymphocyte Globulin (ATLG) may be used for the prevention of severe graft-versus-host disease (GVHD). ATLG targets both the recipient's lymphocytes and those transferred with the graft. Assuming an inverse relation between the recipient's absolute lymphocyte count (ALC) and exposure of remaining ATLG to the graft, we aim to evaluate the impact of the recipient's ALC before the first ATLG administration on the benefits (prevention of GVHD and GVHD-associated mortality) and potential risks (increased relapse incidence) associated with ATLG. Methods: In recipients of HLA-matched, ATLG-based HSCT (n = 311), we assessed the incidence of acute GVHD, GVHD-related mortality and relapse, as well as other transplant-related outcomes, in relation to the respective ALC (divided into tertiles) before ATLG. Results: The top-tertile ALC group had a significantly increased risk of aGVHD (subhazard ratio (sHR) 1.81; [CI 95%; 1.14-2.88]; p = 0.01) and aGVHD-associated mortality (sHR 1.81; [CI 95%; 1.03-3.19]; p = 0.04). At the highest ATLG dose level (≥45 mg/kg), recipients with lowest-tertile ALC had a trend towards increased relapse incidence (sHR 4.19; [CI 95%; 0.99-17.7]; p = 0.05, n = 32). Conclusions: ATLG dosing based on the recipient's ALC may be required for an optimal balance between GVHD suppression and relapse prevention.

Higher abatacept exposure after transplant decreases acute GVHD risk without increasing adverse events

AbstractIn the ABA2 study, the T-cell costimulation blockade agent, abatacept, was safe and effective in preventing acute graft-versus-host disease (aGVHD) after unrelated-donor hematopoietic cell transplant (HCT), leading to US Food and Drug Administration approval. Here, we performed a determination of abatacept pharmacokinetics (PK), which enabled an examination of how abatacept exposure-response relationships affected clinical outcomes. We performed a population PK analysis of IV abatacept using nonlinear mixed-effect modeling and assessed the association between abatacept exposure and key transplant outcomes. We tested the association between the trough after dose 1 (Ctrough_1) and grade (GR) 2 or 4 aGVHD (GR2-4 aGVHD) through day +100. An optimal Ctrough_1 threshold was identified via recursive partitioning and classification tree analysis. This demonstrated that abatacept PK was characterized by a 2-compartment model with first-order elimination. The ABA2 dosing regimen was based on previous work targeting a steady-state abatacept trough of 10 μg/mL. However, a higher Ctrough_1 (≥39 μg/mL, attained in ∼60% of patients on ABA2) was associated with a favorable GR2-4 aGVHD risk (hazard ratio, 0.35; 95% confidence interval, 0.19-0.65; P < .001), with a Ctrough_1 <39 μg/mL associated with GR2-4 aGVHD risk indistinguishable from placebo (P = .37). Importantly, no significant association was found between Ctrough_1 and key safety indicators, including relapse, and cytomegalovirus or Epstein-Barr virus viremia. These data demonstrate that a higher abatacept Ctrough_1 (≥39 μg/mL) was associated with a favorable GR2-4 aGVHD risk, without any observed exposure-toxicity relationships. This trial was registered at www.clinicaltrials.gov as #NCT01743131.