Graft-versus-host Disease Outcomes Research Articles

Safety and efficacy of low dose versus high dose corticosteroid for graft versus host disease (GVHD): A systematic review.

e24047 Background: Graft-versus-host disease (GVHD) is an immune-mediated complication of allogeneic hematopoietic stem cell transplantations. Current standard dose of corticosteroids used by the most hospitals for GVHD patients is 1-2 mg/kg/day. The prednisone dose used in the treatment of a GVHD has been a matter of debate. In this systematic review, we aimed to compare low dose prednisone to high/standard dose prednisone in terms of multiple prognostic outcomes of the patients undergoing allogenic hematopoietic stem-cell transplantations. Methods: We searched the databases PubMed, Cochrane library, and clinicaltrials.gov for all studies investigating the efficacy and safety of low dose and high dose steroid for GVHD. We set the search strategy incorporating the search terms, Graft-versus-host disease," "low dose cortico-steroid," and "high dose corticosteroid", and operated using the Boolean operators ‘AND’, and ‘OR’. Thus, retrieved articles were then exported on an Excel sheet, and duplicates were removed. After selecting the study based on inclusion criteria, data on study characteristics and biomarker description was extracted on a pre-determined data extraction table on the Microsoft Excel. Results: The search revealed 547 studies and 3 studies that met the eligibility criteria of this review have been included.During relapse, chronic GVHD, mortality, and malignancy outcomes were generally similar between doses, low-dose prednisone showed benefits for leukemia-free, relapse-free, and overall survival. Overall, the randomized trial by Chang et al. found lower risks of HZV and pulmonary infections with low-dose prednisone compared to standard-dose. (Table 1) Other infections were similar between groups. Conclusions: Low-dose prednisone showed similar efficacy to standard-dose for most GVHD outcomes (relapse risk, mortality), with potential benefits on survival, reduced HZV/pulmonary infections, and reduced adverse effect of higher cumulative dose of corticosteroids. [Table: see text]

Early Tapering of Cyclosporine Is Feasible in Haploidentical Stem Cell Transplantation: A Single Center Experience.

Cyclosporine-A (CsA) and post transplantation cyclophosphamide (PTCy) are common agents used for graft versus host disease (GVHD) prophylaxis in Haploidentical hematopoietic cell transplantation (haplo-HCT). However, the impact of CsA cessation timing in the posttransplant setting on clinical outcomes is uncertain. We aimed to investigate the impact of a novel approach that integrated early CsA cessation with PTCy utilization. This study was a single arm retrospective study carried out at a tertiary referral hospital hematology and bone marrow transplantation center between 2009 and 2022. The patients who received haplo-HCT with ATG, PTCy and CsA as GVHD prophylaxis were included. CsA was planned for cessation starting at day 45 to day 60. Acute and chronic GVHD were evaluated and graded. CsA blood concentrations and its impact on acute and chronic GVHD was evaluated. Thirty-one patients composed of 19 (61.3%) male and 12 (38.7%) female patients with a median age of 31 years (20-58). Busulfan and TBI based conditioning regimens were the most utilized regimens. The majority of donors were first degree relatives. Stem cell origin was peripheral blood for all patients. GVHD prophylaxis consisted of ATG, CsA and PTCy. Acute GVHD was observed in 9 (29%) cases, whereas chronic GVHD was seen in 3 (9.7%) cases, with 2 of them having overlapping GVHD. Age, gender, number of chemotherapy lines, transplant characteristics, infused CD34 cell count, and engraftment durations were similar among patients with and without GVHD. Patients with GVHD had similar 1st, 2nd, 3rd and 4th week CsA concentrations compared to patients without GVHD (p>0.05). The presence of GVHD was not associated with worse progression free survival and overall survival (p=0.6, p=0.5, respectively). CMV reactivation was more common in the GVHD group. In the current study, we did not find an impact of CsA concentration on GVHD and post-transplant outcomes in Haplo-HCT setting. Therefore, together with the use of PTCy, early CsA cessation can be an option; further studies are needed to understand all aspects of this approach.

Graft-versus-host disease after an outpatient peripheral blood hematopoietic cell transplant using reduced-intensity conditioning: a single-center LATAM experience

ABSTRACT Background HLA compatibility predicts allogeneic hematopoietic cell transplant (allo-HCT) and graft-versus-host disease (GvHD) outcomes. There is insufficient information regarding GvHD outcomes for outpatient HLA-identical and haploidentical-HCT employing reduced-intensity conditioning (RIC). Research design and methods We compare GvHD outcomes between donor types and report risk factors associated with GvHD. Stem cell source was T-cell replete peripheral blood. GvHD prophylaxis was post-transplant cyclophosphamide (PT-CY), mycophenolic acid, and calcineurin inhibitors for haploidentical (n = 107) and oral cyclosporine (CsA) plus methotrexate i.v. for HLA-identical (n = 89) recipients. Results One hundred and ninety-six HCT transplant patients were included. aGvHD and cGvHD frequency were similar between HCT types. aGvHD severity was comparable, but severe cGvHD was less frequent in the haploidentical group (p = .011). One-hundred-day cumulative incidence (CI) of aGvHD for haploidentical and HLA-identical was 31% and 33% (p = .84); 2-year CI of cGvHD was 32% and 38% (p = .6), respectively. Haploidentical recipients had less steroid-refractory cGvHD (p = .043). Patients with cGvHD had less 2-year relapse (p = .003); both aGvHD and cGvHD conferred higher OS (p = .010 and p = .001), respectively. Male sex was protective for steroid-refractory cGvHD (p = .028). Conclusions Acute and chronic GvHD rates were comparable between HLA-identical and haploidentical transplant groups. cGvHD severity was lower in the haploidentical group.

Mesenchymal stem cells preconditioned with a TLR5 agonist enhanced immunoregulatory effect through M2 macrophage polarization in a murine graft-versus-host disease model.

Graft-versus-host disease (GVHD) is a common complication following hematopoietic stem cell transplantation and can be life-threatening. Mesenchymal stem cells (MSCs), adult stem cells with immunomodulatory properties, have been used as therapeutic agents in a variety of ways and have demonstrated efficacy against acute GVHD (aGVHD); however, variability in MSC pro- and anti-inflammatory properties and the limitation that they only exhibit immunosuppressive effects at high levels of inflammation have prevented their widespread clinical use. The outcomes of GVHD treated with MSCs in the clinic have been variable, and the underlying mechanisms remain unclear. Therefore, the unique biological effects of Toll-like receptor 5 (TLR5) agonists led us to compare and validate the efficacy of MSCs primed with KMRC011, a TLR5 agonist. KMRC011 is a stimulant that induces the secretion of cytokines, which play an important role in immune regulation. In this study, we found that MSCs pretreated with KMRC011 increased the secretion of immunosuppressive cytokines indoleamine 2,3-dioxygenase (IDO) and cyclooxygenase-2 (COX2) and increased the expression of M2 macrophage polarizing cytokines macrophage colony-stimulating factor (M-CSF) and interleukin 10 (IL-10) in vitro. We investigated the immunosuppressive effects of TLR5 agonist (KMRC011)-primed MSCs on lymphocytes and their preventive and therapeutic effects on an in vivo mouse aGVHD model. In vitro experiments showed that KMRC011-primed MSCs had enhanced immunosuppressive effects on lymphocyte proliferation. In vivo experiments showed that KMRC011-primed MSCs ameliorated GVHD severity in a mouse model of induced GVHD disease. Finally, macrophages harvested from the spleens of mice treated with KMRC011-primed MSCs showed a significant increase in the anti-inflammatory M2 phenotype. Overall, the results suggest that KMRC011-primed MSCs attenuated GVHD severity in mice by polarizing macrophages to the M2 phenotype and increasing the proportion of anti-inflammatory cells, opening new horizons for GVHD treatment.

Analysis of Hospitalization Outcomes in Bone Marrow Transplant Patients with Graft-Versus-Host Disease: A Nationwide Study

Background: Graft-versus-host disease (GVHD) is a well-known complication in patients with bone marrow transplantation. There is a need for additional data on the in-patient outcomes of GVHD in patients who have undergone bone marrow transplantation. Our analysis aims to evaluate the outcomes of GVHD in hospitalized patients with bone marrow transplantation. Method: In this retrospective study, we utilized data from the National Inpatient Sample (NIS) database from 2016 to 2019. Using ICD-10 codes, we identified hospitalizations involving bone marrow transplantation and categorized them into two groups: those with GVHD and those without GVHD. To account for potential confounding variables, we considered a comprehensive set of factors, including age, sex, race, zip code-based income quartile, hospital region, hospital teaching status, hospital division, hospital bed size, insurance status, and the Charlson comorbidity index score. We performed univariable logistic regression analysis to calculate unadjusted odds ratios. Subsequently, we conducted a multivariable logistic regression analysis to account for potential confounding effects and calculated adjusted odds ratios.(see Figure), where the model included only variables that were found to be associated with the outcome of interest in the univariable regression analysis at a significance level of P < 0.2. Proportions were compared using the Fisher exact test for categorical variables, and continuous variables were compared using the Student t-test. All P-values were two-sided, and the significance level was set at P < 0.05, indicating statistical significance. Results: From 2016 to 2019, data were collected from 13,999 hospitalizations involving bone marrow transplants. Among these cases, 836 hospitalizations were linked to GVHD patients. A comparison of patient characteristics showed that individuals with GVHD had a mean age of 51.61 years, while those without GVHD had a slightly higher mean age of 55.55 years. There were slight variations in gender and race distributions between the two groups, with a higher percentage of males and whites observed in the GVHD group compared to the group without GVHD. The analysis of outcomes between the two groups revealed significant differences. Patients with GVHD experienced notably longer mean lengths of stay (41.40 days vs. 21.31 days, P = 0.000) and incurred higher mean total hospital charges ($824,058 vs. $335,765, P = 0.000). Furthermore, after adjusting for confounding factors, GVHD posed a substantial risk to patients undergoing bone marrow transplantation. The adjusted odds ratio (aOR) for mortality in those with GVHD was 7.20 (95% CI: 5.54 to 9.36, P = 0.000) compared to those without GVHD, indicating a considerably higher risk of death. The coefficient for the length of stay was 19.36 days (95% CI: 17.29 to 21.42), and the coefficient for total hospital charges was $453,733 (95% CI: $396,577 to $510,889) in patients with GVHD compared to those without GVHD hospitalizations. Moreover, the presence of GVHD in patients was associated with elevated risks of various medical conditions. The adjusted odds ratios (aORs) for sepsis, pneumonia, acute respiratory failure, intubation and mechanical ventilation, Clostridium difficile infection, and acute kidney injury (AKI) in patients with GVHD were 2.79 (95% CI: 2.28 to 3.41, P = 0.000), 3.30 (95% CI: 2.57 to 4.24, P = 0.000), 5.10 (95% CI: 4.01 to 6.49, P = 0.000), 4.88 (95% CI: 3.75 to 6.34, P = 0.000), 1.45 (95% CI: 1.13 to 1.86, P = 0.003), and 3.57 (95% CI: 2.97 to 4.29, P = 0.000), respectively (see Figure). Conclusion: Patients with GVHD in patients with bone marrow transplantation experience higher mortality rates, extended hospital stays, and increased hospital charges. Additionally, they are at a significantly higher risk of developing severe medical conditions, including sepsis, pneumonia, acute respiratory failure, Clostridium difficile infection, and acute kidney injury (AKI). These findings highlight the importance of closely monitoring and effectively managing GVHD to enhance patient outcomes and alleviate the burden of complications associated with bone marrow transplantation. Nevertheless, further prospective studies are necessary to gain a deeper understanding and more comprehensive evaluation of the outcomes in these hospitalized patients.

HLA-DRB1 Hed Is Associated with Improved Survival and Decreased Relapse in Patients with Hematologic Malignancies Following Allogeneic Hematopoietic Stem Cell Transplant

Introduction: Despite advances in disease monitoring and maintenance therapies, the risk of relapse following allogeneic hematopoietic cell transplant (HCT) remains a major concern. Attention has turned to understanding how diversity across the immune system can influence tumor surveillance. Due to their protein's integral role in binding and presenting antigens to immune cells, HLA genes have been a major focus because a high number of polymorphisms alter their peptide-binding grooves and impact their repertoire of antigens. Based on the heterozygote advantage hypothesis, heterozygous HLA genotypes were thought to better elicit immune responses due to a higher probability of binding antigens. Further refinement of HLA diversity centers on the immunopeptidome and variations in peptide-binding specificities. HLA evolutionary divergence (HED) represents a quantitative measure of physiochemical sequence divergence between peptide-binding grooves encoded by HLA alleles. Greater sequence divergence across HLA alleles leads to a more expansive repertoire of antigens and helps to explain that high HED was associated with improved overall survival (OS) in patients with solid tumors treated with immune checkpoint inhibitors (Chowell et al. Nat Med, 2019). With a more diversified immune response, we hypothesize that high HED will improve tumor surveillance and impact survival and relapse following allogeneic HCT. Methods: Patients who underwent 8/8 HLA-A, -B, -C and -DRB1 matched first allogeneic HCT for AML, MDS, ALL, CML, or lymphoma between 2008-2018 were identified from the CIBMTR database. All patients received myeloablative conditioning, except for those patients with lymphoma. Using donor HLA typing to the allele level and reference amino acid sequences for peptide binding domains, HLA HED was calculated for each HLA class I allele (-A,-B,-C) and HLA class II allele (-DRB1) using the Grantham Distance metric (Pierini, et al. Mol Biol Evol, 2018). An overall mean HED score was calculated for HLA class I and HLA-DRB1 alleles and was initially divided at the median to classify high versus low HED. HED was then evaluated based on quartiles with high HED defined as overall mean HED greater or equal to the upper quartile. The primary outcomes were OS and relapse. Secondary outcomes included transplant-related mortality (TRM), disease-free survival (DFS), and graft-versus-host disease (GVHD). Multivariate analysis using Cox proportional hazards model was performed with factors violating the proportional hazards assumptions adjusted through stratification. P-value ≤ 0.01 was significant for this study. Results: A total of 9,231 patients received an 8/8 HLA-matched allogeneic HCT from 2008-2018 according to selection criteria. With high HED defined by the median, there was no association with OS and HLA class I HED (HR 1.00; 95% CI 0.93 - 1.07, P=0.935) or with HLA-DRB1 HED (HR 0.96; 95% CI 0.91 -1.02, P=0.225). Relapse was not associated with HLA class I HED (HR 1.04, 95% CI 0.96-1.12, P=0.354) or with HLA-DRB1 HED (HR 0.99, 95% CI 0.93 - 1.06, P=0.857). There were no significant associations with HED and the secondary outcomes of TRM, DFS, or GVHD. HED was then characterized by quartiles. High HLA-DRB1 HED (upper quartile) was associated with improved OS (HR 0.91; 95% CI 0.85 - 0.96, P=0.0019) and decreased relapse (HR 0.87; 95% CI 0.80 - 0.95, P=0.0014) when compared to low HED (Q1-Q3). Improved DFS was observed with high HLA-DRB1 HED but failed to achieve statistical significance (HR 0.92; 95% CI 0.86 - 0.98, P=0.011). There was no association between HLA class I HED and OS, relapse, or DFS. Conclusions: High HLA-DRB1 HED, defined as upper quartile, was associated with improved OS and decreased relapse in patients with hematologic malignancies following allogeneic HCT. High HED promotes a diverse repertoire of antigens, which may heighten tumor surveillance and enhance graft versus leukemic effect. Since similar associations were not replicated when high HED was defined by the median, the effects of HLA-DRB1 HED are most likely observed in the most divergent donor-recipient HLA pairings. Previous work has implicated the role of HLA class II alleles in affecting immune function and contributing to relapse following HCT. Therefore, HLA-DRB1 may play a more integral role in tumor surveillance post-HCT, which can have important implications in donor selection, especially in HLA mismatched settings.

Correlation between Clinical Diagnosis and Histopathological Findings of Liver Dysfunction after Allogeneic-HSCT

Liver dysfunction is one of the dismal complications after allogeneic hematopoietic cell transplantation (Allo-HCT). Although most frequently suspected complications are hepatic graft-versus-host disease (GVHD) and toxic hepatitis, precise diagnosis can be challenging. In order to accurately diagnose hepatic dysfunction after allo-HCT, liver biopsies are occasionally done. However, even after attaining pathology, discerning between overlapping pathologic findings among different hepatic complications, still remains to be a challenge. We tried to review the pathologic findings of liver biopsies of patients with elevated liver enzymes after allo-HCT. We obtained 92 liver biopsy samples from 88 patients who underwent allo-HCT in Catholic Hematology Hospital from 2008 to 2023. All patients showed elevated liver enzymes presenting with either cholestatic pattern (hyperbilirubinemia and/or high alkaline phosphatase [ALP] or gamma glutamyl-transferase [GGT]) or hepatocellular pattern (elevating AST/ALT levels). Clinical course, laboratory and pathological findings were acquired on the date of liver biopsy. Acute hepatic GVHD was assessed according to the original Glucksberg criteria. Chronic hepatic GVHD was assessed by the National Institutes of Health criteria 2014. Hepatic GVHD was clinically diagnosed in patients showing elevated ALP or GGT with hyperbilirubinemia (typical cholestatic) or elevated aminotransferase (hepatic variant). Median duration to the date of biopsy after allo-HSCT was 6.3 months (range, 0.8 to 61.3). Hepatic GVHD was divided into typical cholestatic pattern (n=30) and hepatic variant (n=28). Other clinical features were isolated hyperbilirubinemia (n=17), elevation of aminotransferase (n=8), HBV reactivation (n=5), toxic hepatitis (n=2), liver cirrhosis (n=1), and PTLD (n=1). Among 30 cholestatic hepatic GVHD cases, 20 biopsies revealed early pathologic features including bile duct damage and portal lymphocytic infiltration, 9 showed late features including loss of bile duct and fibrosis, and 1 showed non-specific findings. Among 28 hepatic-variant GVHD cases, 22 biopsies revealed early pathologic features, 5 showed late features including loss of bile duct and fibrosis, and 1 showed non-specific findings. All 8 isolated aminotransferase elevation cases showed typical GVHD findings (early feature 6, late feature 2), while 17 isolated hyperbilirubinemia cases showed 8 hepatitis pathology, 5 GVHD, 3 VOD, and 1 hemochromatosis. Among our final 36 hepatic variant GVHD cases, 35 (97.2%) patients showed GVHD improvement after treatment, while among final 35 cholestatic GVHD cases, 15 (42.8%) showed response (p<0.001). Our clinical diagnosis for hepatic GVHD well correlated with pathologic findings. Clinical outcome of hepatic GVHD with cholestatic pattern was far worse than hepatic variant GVHD. Isolated aminotransferase elevation strongly correlated with pathology consistent with GVHD. As isolated hyperbilirubinemia was related with various pathologic findings, we recommend liver biopsy in this group of patients in order to discern between different etiologies.

T-Cell Depletion with Both Reduced Dose Anti-Thymocyte Globulin and Reduced Dose Post-Transplant Cyclophosphamide in Haploidentical Peripheral Blood Stem Cell Transplantation for Acute Leukemia and Myelodysplatic Syndrome

Graft-versus-host disease (GVHD) prophylaxis in allogeneic hematopoietic stem cell transplantation from HLA haplo-identical familial donor (haplo-HSCT) is based on in vivo T-cell depletion with either anti-thymocyte globulin (ATG) or post-transplant cyclophosphamide (PTCy). ATG has made significant contributions to enabling haplo-HSCT. However, the benefit of ATG may be often mitigated by higher risk of viral reactivation, including cytomegalovirus (CMV) and Epstein-Barr virus (EBV) due to a slower immune reconstitution. PTCy revolutionized HLA-mismatched HSCT and rapidly became the standard-of-care. However, it also has problems due to a cytokine release syndrome (CRS) -like symptoms and excessive cytotoxicity leading to the risk of acute cardiotoxicity and the possibility of alleviated graft-versus-leukemia effect. Considering a demand for more optimal in vivo T-cell depletion, we tried to combine both ‘lower-dose’ ATG and ‘lower-dose’ PTCy before and after stem cell infusion, respectively, hoping they can mitigate their individual limitations while maintaining the effectiveness of in vivo T-cell depletion. We retrospectively included 60 adults with acute leukemia or myelodysplastic syndrome who underwent haplo-HSCT following busulfan (3.2 mg/kg/day for 4 days as myeloablative and for 2 days as reduced intensity conditioning) and fludarabine (a total of 160 mg/m 2) between January 2019 and June 2023. Among them, 32 received a novel combination of ATG (a total of 3.0, 3.5, or 4.0 mg/kg depending on the absolute lymphocyte count level on days -3) and PTCy (50mg/kg on day +3 and 30mg/kg on day +4) compared to 28 patients who received ATG only (2.5 mg/kg/day from days -3 to -1, a total of 7.5 mg/kg) as in vivo T-cell depletion. Most patients received cyclosporine and mycophenolate mofetil as GVHD prophylaxis. The median follow-up duration for all patients was 8 months (median 9 months in the ATG/PTCy group and 7.5 months in the ATG group, respectively; P = 0.744). Baseline characteristics including age, sex, disease status, modified EBMT score, and the intensity of conditioning, were well-balanced except slightly higher infused CD34+ cells in the ATG/PTCy group (median 5.2 vs. 4.7 x 10 6/kg, P = 0.042). The cumulative incidence of acute GVHD at day +100 and moderate to severe chronic GVHD at 1 year were significantly lower in the ATG/PTCy group compared to the ATG group, respectively [grades II-IV acute GVHD: 20.4% (95% confidence interval [CI], 4.3-33.8%) vs. 48.4% (95% CI, 25.2-64.4%), P = 0.014; grades III-IV acute GVHD: 7.5% (95% CI, 0-17.1%) vs 31.1% (95% CI, 10.5-46.9%), P = 0.019; and moderate to severe chronic GVHD: 9.5% (95% CI, 0-21.2%) vs. 60% (95% CI, 23.3-79.1%), P = 0.007]. The ATG/PTCy group had a tendency of less incidence and severity of the haplo-fever. Multivariate analysis showed a significantly higher GRFS (hazard ratio 0.35, P = 0.002) and OS (hazard ratio 0.4, P = 0.014) for an ATG/PTCy group. The use of dual T-cell depletion with the reduced dose ATG in combination with the reduced dose PTCy showed a significantly superior early transplant outcome over with ATG of 7.5 mg/kg in terms of both GVHD and survival outcomes.

B-Cell Acute Lymphoblastic Leukemia: Donor Matters in Allogeneic Stem Cell Transplant Outcomes of Hispanic Patients

Introduction: Hematopoietic stem cell transplantation (HSCT) improves long term overall survival (OS) and disease-free survival (DFS) in those with intermediate or high-risk B- cell ALL. Historically, matched related donors were the ideal choice, but with improved GVHD prophylactic regimens and supportive care, haploidentical donors are being increasingly used. Due to their increased graft-versus-leukemia (GVL) effect, they may be an option for Hispanic patients, for whom matched donation may be more challenging. Methods: This is a retrospective chart review of B- cell ALL patients that received allogeneic HSCT at Norris Comprehensive Cancer Center (NCCC) from 2012 to 2023. Mismatch-unrelated donors were excluded. For OS, DFS, and cumulative incidence of relapse (CIR), match sibling donors (MSD) and match unrelated donors (MUD) were grouped. However, for GVHD outcomes including graft-versus-host disease (GVHD)-free relapse-free survival (GRFS), incidence of grade 3-4 acute GVHD (aGVHD), and incidence of severe chronic GVHD (cGVHD) requiring immunosuppression MSD and MUD were separated. Incidence outcomes were evaluated using competing risk regression (Fine-Gray method), with death as a competing outcome, while survival outcomes were analyzed using Cox proportional hazards model. Results: One hundred eighteen B- cell ALL patients were included with a median age at transplant of 43 years (range: 21-69). Donor types included 46 (40.0%) MSD, 45 (38.1%) haploidentical, and 27 (22.9%) MUD. Most were Hispanic (N= 92, 78.0%) and our median follow-up time was 23.6 months. The majority of patients achieved CR1 (N=79, 66.9%) and MRD negativity by flow (N=106, 89.8%), pre-transplant. The 3-year OS and DFS for the cohort were 82.1% (95% CI 73.8-91.3%) and 66.2% (95% CI 57.2-76.6%), respectively, while the CR1 subgroup was 90.5% (95% CI 83.3-98.3%) and 77.1% (95% CI 67.8-87.7%) respectively. When compared to haploidentical HSCT, patients who received matched donors had significantly worse CIR (HR = 2.42; 95% CI 1.06-5.51; P = 0.036) and DFS (HR = 2.14; 95% CI 1.03-4.44; P = 0.041), along with a non-significant trend towards worse OS (HR = 2.54; 95% CI 0.83-7.80; P=0.10). Additionally, pretransplant minimal residual disease (MRD) positivity demonstrated worse OS (HR = 5.01; 95% CI 1.73-14.5; P = 0.003), DFS (HR = 3.25; 95% CI 1.48-7.16; P = 0.003), and CIR (HR = 2.05; 95% CI 0.78-5.39; P = 0.15). The 1-year GRFS, 1-year incidence of severe cGVHD, and 100-day incidence of grade 3-4 aGVHD was 52.6% (95% CI 43.5-63.6%), 29.5% (95% CI 20.9-38.6%), and 7.74% (95% CI 3.79-13.5%), respectively. Compared to haploidentical donors, GRFS was worse in the MUD (HR = 2.07; 95% CI 1.08-3.96; P = 0.028) but similar in MSD. This is likely driven by differences in survival and relapse, and there were no differences in the incidence of severe cGVHD or aGVHD between donor types. Multivariate analysis, which included age, MRD status pretransplant, and stage prior to transplant, demonstrated the improved predictive effect of haploidentical donors. Matched donors exhibited worse DFS (HR = 2.25; 95% CI 1.04-4.90; P = 0.04) and CIR (HR = 2.47; 95% CI 1.09-5.60; P = 0.03), with a trend towards worse OS (HR = 2.84; 95% CI 0.92-8.79; P = 0.07). Given the heterogeneity in donor-type outcomes, we conducted a subgroup analysis of the 45 haploidentical HSCT patients on the GRFS and DFS composite outcomes. After controlling for patient age, older donor age analyzed as a continuous variable was a significant predictor of worse GRFS (HR = 1.05; 95% CI 1.00-1.11; P = 0.039) but did not affect DFS. Conclusion: In a predominantly Hispanic population of ALL patients, haploidentical donors demonstrate improved OS and CIR. In those haploidentical patients, younger donor age confers improved GRFS.

Risk-Adapted Donor Lymphocyte Infusion after Hematopoietic Cell Transplant in Pediatric and Young Adult Patients Is Associated with Low Risk of Graft Versus Host Disease

Introduction: Donor lymphocyte infusion (DLI) is a form of adoptive immunotherapy administered to enhance the graft-versus-leukemia (GVL) effect after an allogeneic hematopoietic cell transplantation (HCT). DLI is frequently chosen for its ease of administration and low risk of graft ablation as compared with other chemotherapeutic options in patients experiencing mixed chimerism (MC) or disease relapse. But in patients with acute leukemia experiencing relapse, clinical responses are seen in fewer than 20-30%. Success is also limited by the occurrence of acute and chronic graft-versus-host disease (GVHD). We had previously described our risk-adapted strategy of administering DLIs based on chimerism and donor source (Rujkijyanont P, et al. Blood Cancer J 2013). To determine the efficacy and toxicity of DLIs and to identify potential factors influencing the outcomes, we conducted a retrospective single center study including patients who received DLIs after HCT. Methods: We collected data on all HCTs and conventional DLIs that had been administered to patients from 1993 to 2022 for any indication at our center. Each HCT was considered as an independent event. Numeric variables were represented by median and range and compared using the Wilcoxon-Mann-Whitney test. Categorical variables were compared using the Fisher exact test. Competing-risk regression models using the Fine-Gray method were developed to evaluate risk factors for acute GVHD and chronic GVHD. Death and relapse were considered as competing risk events for these GVHD outcomes. Follow-up data were censored at subsequent HCT, 2 years after the first DLI, 5 years after transplant, or the last follow-up. Logistic regression analysis was performed to assess factors associated with the response to DLI within 180 days after the first DLI. Results: During the study period, 236 patients received 252 HCTs followed by DLIs (median age at HCT 9.2 [range 0.2-25.1] years). An additional 743 patients received 806 HCTs with no subsequent DLI (median age at HCT 10.3 [range 0.1-27.2] years). Dosing most frequently used was 1 × 10 5, 1 × 10 6 and 1 × 10 7 CD3+ cells/kg, for haploidentical donor (HAPLO), matched unrelated donor (MUD) and matched sibling donor (MSD) recipients, respectively. Initial doses were occasionally lower based on risk of GVHD and were escalated as tolerated and based on response. After receiving DLI, 19.4% developed acute GVHD, and 9.2% developed chronic GVHD with no significant differences observed between MSD, MUD and HAPLO recipients. After adjusting for donor source, longer duration between HCT and DLI was associated with a significantly decreased risk of both acute (HR 0.97 P<0.001) and chronic GVHD (HR 0.98 P=0.04). A higher CD3+ cell dose was also significantly associated with an increased risk of acute GVHD (HR 1.03 P<0.001) but not chronic GVHD (HR 0.96 P=0.12). The overall response rate after DLI for treating MC or graft failure was 45.2% for MSD, 32.6% for MUD and 41.4% for HAPLO recipients. Logistic regression analysis revealed leukemia patients had a higher response rate after receiving a DLI for mixed chimerism from MSD (OR=19.5 P=0.002) and HAPLO (OR=9.03 P=0.042), but not from MUD HCT (OR=0.65 P= 0.57), compared to patients with non-malignant disorders. We also evaluated the response to DLI for frank disease relapse in 15 patients. The response rate after DLI for disease relapse was 50% (1/2) for MSD, 44.4% (4/9) for HAPLO, but 0% (0/4) for MUD recipients. Conclusions: In our analysis, the incidence of GVHD was not higher in pediatric and young adult HCT recipients who received DLI as compared to those who did not. Overall, the risk of developing acute and chronic GVHD after DLI was low and comparable between different donor sources. The risk of GVHD decreased further away from HCT and increased with higher DLI dose. The response rate for treating MC and disease relapse remains less than 50%. Thus, DLIs may be safely administered to pediatric and young adult patients after HCT. The therapeutic effect may be modulated by adjusting the dose, timing and frequency of DLI administration.

Microbiota-Specific T Cells Contribute to Graft-Versus-Host Disease after Allogeneic Stem Cell Transplantation

Background: Allogeneic T-cell expansion is the primary determinant of graft-versus-host disease (GVHD), and current dogma dictates that this is driven by histocompatibility antigen disparities between donor and recipient. This paradigm represents a fixed genetic system within which donor T cells interact with recipient-derived peptide-MHC complexes. However, the current model does not account for potential cognate interactions between donor T cells and microbe-derived antigen presented by the recipient. Prior studies in healthy patients have demonstrated the existence of circulating αβT cells targeting common bacterial species in the gastrointestinal (GI) tract. Whether microbe-specific T cells derived from the donor graft impact GVHD outcomes has not been studied. We tested the hypothesis that the recipient GI microbiota serve as a source of cognate antigen, contributing to clonotypic donor T-cell expansion and induction of GVHD. Methods: Functional studies utilized allogeneic stem cell transplant models in murine systems including both matched (Marilyn Tg to B6 male) and mismatched (B6 to B6D2F1) transplants as well as inducible MHCII knockout mice. Microbiota-specific transgenic T cells (MSTCs) targeting commensal flagellin (CBir1) and vendor-specific microbiome (segmented filamentous bacteria - SFB) in the context of I-A(b) were incorporated as part of the donor graft. Mechanistic studies utilized flow cytometry, cytokine stimulation and profiling, single-cell RNA sequencing, gene set enrichment analysis, NFAT-GFP T-hybridoma reporters, live-cell imaging (xCelligence RTCA eSight), and tissue analysis with RNA in-situ hybridization (ISH). Results: MSTCs lethally augmented GVHD when given as part of the donor graft in respectively colonized recipients. Taconic B6 male recipients (SFB-bearing) developed lethal GVHD when both donor Marilyn (Allo) Tg T cells and SFB T cells were introduced, but not when either transgenic T cell was introduced alone ( Figure A, p<0.0001). In contrast, Jackson B6 recipients (SFB-absent) receiving both Allo and SFB T cells did not develop lethal GVHD ( Figure A, p<0.0001), confirming functional relevance of microbe-specificity among the donor T cell pool. Lethal GVHD was also seen with addition of CBir1 T cells to the donor graft but not with addition of bulk T cells (log-rank p<0.0001). Similar results were seen in a mismatched transplant system. To determine how MSTCs promoted lethality in the context of an allogeneic (allo) response, we performed scRNA sequencing of T cells harvested in the recipient spleen at day 6 post-transplant (prior to mortality onset). Post-transplant MSTCs harbored a naïve phenotype (Sell high/CD44 low/CD69 low) when given as the primary source of donor T cells but shifted to an early activated phenotype (Sell int/CD44 low/CD69 high/TCF7 low) when Allo T cells were concurrently introduced (ANOVA q<0.01). MSTC activation was confirmed with augmented expression of IFNγ upon PMA/ionomycin stimulation observed in allo vs. syngeneic response (Wilcoxon rank-sum, p< 0.01). Introduction of Allo T cells increased the abundance of MSTCs in the mesenteric lymph nodes (day 5, 6, Wilcoxon, p<0.01). Ablation of MHCII on the GI epithelial surface using Villin-CreERT2 I-Ab flox recipients abrogated microbe-specific T cell activation in co-culture with recipient GI intraepithelial cells harvested at day 6 post-transplant vs. non-ablated control (8, 12, 24-hr NFAT-GFP intensity, p<0.001). RNA ISH probes targeting the CDR3 region of anti-microbial CBir1 T cells demonstrated an increase in MSTC infiltration at day 6 in the recipient GI lamina propria during an allo response ( Figure B) compared to a syngeneic response (# of MSTCs/terminal ileum cross section at day 6, Wilcoxon p<0.01). Conclusions: We confirm that clonotypic T cell expansion following allogeneic transplantation is not only driven by donor-recipient genetics, as reflected by major and minor histocompatibility matching, but also by differences in microbiota composition that can serve as a source of antigenic stimulation, providing a feed-forward mechanism to propagate GVHD. Furthermore, in the context of an alloreactive T cell response that damages gut integrity, microbial antigens can be presented by GI epithelia, allowing the gut to be concurrently targeted by microbiota specific T cells whose function is additionally enhanced by the alloreactive response.

Effect of graft-versus-host disease on outcomes of HLA-haploidentical peripheral blood transplantation using post-transplant cyclophophamide.

There is limited evidence regarding the association between graft-versus-host disease (GVHD) and reduced relapse in patients who undergo allogeneic hematopoietic stem cell transplantation from haploidentical donors (haplo-HSCT) using post-transplant cyclophosphamide (PTCY). We investigated the association between GVHD and transplant outcomes in 938 patients who received haplo-HSCT using PTCY. Overall survival (OS), relapse rate, and non-relapse mortality (NRM) were evaluated using landmark analysis at the landmark points at 100 and 360 days after HSCT for acute and chronic GVHD, respectively. Grade I-II acute GVHD was not associated with OS (adjusted hazard ratio: 1.15, 95% confidence interval: 0.85-1.57), relapse (1.03, 0.74-1.45) and NRM (1.15, 0.74-1.77). Conversely, grade III-IV acute GVHD was associated with higher NRM (3.16, 1.61-6.19), but no other outcomes. Limited chronic GVHD was not associated with OS (1.11, 0.48-1.95), relapse (1.05, 0.30-3.75) and NRM (1.30, 0.45-3.79). Extensive chronic GVHD was associated with higher NRM (2.40, 1.03-5.57), but no other outcome. In conclusion, any GVHD was not associated with a reduced relapse rate and improved OS, and Grade III-IV acute GVHD and extensive chronic GVHD were associated with higher NRM in patients who received haplo-HSCT using PTCY.

Risk factors and clinical characteristics of acute and chronic cutaneous graft-versus-host disease in pediatric patients undergoing hematopoietic stem cell transplantation.

Acute and chronic cutaneous graft-versus-host disease (GVHD) are common complications following hematopoietic stem cell transplantation (HSCT) in pediatric patients. In this retrospective study, we explored the risk factors and clinical characteristics of acute and chronic cutaneous GVHD in a case series of children undergoing HSCT at a tertiary referral hospital. We found that 36% of acute cutaneous GVHD was severe and these patients were more likely to have an unrelated donor, and that children with acute cutaneous GVHD who progressed to chronic cutaneous GVHD had a higher proportion of malignant diseases, total body irradiation, and bronchiolitis obliterans compared to those who did not progress to chronic cutaneous GVHD. Our study highlights the importance of identifying and monitoring these high-risk patients to improve the clinical management and outcomes of cutaneous GVHD in pediatric HSCT recipients.

Incidence and risk factors of graft-versus-host disease after liver transplantation: A national study 2010-2020.

Graft-versus-host disease (GVHD) is a common complication of hematopoietic cell transplantation, and its incidence is low in liver transplantation (LT). Estimating the incidence of GVHD after LT is challenging due to the paucity of available data from the United Network for Organ Sharing. This is the first national analysis of the incidence and risk factors of GVHD after LT. This retrospective cohort study used the National Readmission Database to calculate the incidence rate of GVHD within 1 year of LT using survival analysis. The predictors of GVHD were identified using univariate and multivariate Cox regression analyses. From 2010 to 2020, of 88,433 LTs, 383 cases of GVHD occurred within 1 year after LT, resulting in an incidence rate of 1.0% (95% CI: 0.8%-1.3%). We observed no statistically significant change in the incidence of GVHD after LT from 2010 to 2020 (beta-coefficient, -0.07%; 95% CI: -0.17% to 0.04%, p = 0.188). Interestingly, alcohol-associated liver disease was associated with a lower risk of GVHD (adjusted HR, 0.57; 95% CI: 0.36-0.91, p = 0.018), whereas a higher risk was found to be related to a secondary diagnosis of COVID-19 on index admission. Our study found that the incidence rate of GVHD within 1 year of LT in the United States was 1.0% and remained stable from 2010 to 2020. The predictors associated with GVHD include alcohol-associated liver disease and COVID-19. Our study provides valuable insights into the incidence, risk factors, and outcomes of GVHD after LT.

Post-transplantation Cyclophosphamide-based Graft-versus-host-disease Prophylaxis Compared to Methotrexate-cyclosporine a in Matched-related Allogeneic Hematopoietic Stem Cell Transplantation.

Post-transplant cyclophosphamide (PTCy) has shown promising results with low rates of severe graft-versus-host-disease (GVHD), either alone or combined with conventional immunosuppression (CIS). However, studies comparing PTCy with CIS as a GVHD prophylaxis are scarce. The study aimed to determine the rates of GVHD and survival outcomes for patients undergoing peripheral blood stem cell transplant (PBSCT) from HLA-matched related donors (MRD) receiving PTCy-based GVHD prophylaxis and compare these outcomes with those of patients receiving methotrexate (MTX) and cyclosporine-A (CsA) as a GVHD prophylaxis. Seventy-five patients with advanced hematologic malignancies who underwent MRD allogeneic hematopoietic cell transplantation (allo-HCT) were analyzed prospectively. These patients received PTCy and CSA as a GVHD prophylaxis (therapeutic group) and their outcomes were compared with those of 75 retrospectively collected patients who received methotrexate and CsA as a GVHD prophylaxis (historical group) from the same two transplant centers. The median recipient age was significantly lower in the MTX/CsA group at 28 years compared to 34 years in the PTCy/CSA group. Peripheral blood was the only graft source used. All patients had a complete MRD, with two patients having a one-antigen mismatched related donor within the PTCy/CsA group. The 1-year cumulative incidence (CI) of chronic GVHD was 13.4% with PTCy/CsA and 38.6% with MTX/CsA (P = .001). Acute GVHD CI across all grades did not differ between the groups, with 10.7% for PTCy/CsA and 14.7% for MTX/CsA (P = .46). At two years, the overall survival (OS) (54.4% vs 67.2%, P = 0.282), disease-free survival (DFS) (54.1% vs 66.1%, P = 0.358), relapse rates (27.4% vs 20.1%, P = 0.245), and non-relapse mortality (NRM) (29.3% vs 25%, P = 0.904) did not differ between PTCy/CsA and MTX/CsA, respectively. PTCy-based GVHD prophylaxis in MRD transplant is feasible and leads to lower chronic GVHD rates without causing a significantly different risk of relapse or survival than MTX/CsA. More extensive studies are needed to confirm our results.

Corticosteroids as graft-versus-host disease prophylaxis for allogeneic hematopoietic cell transplant recipients with calcineurin inhibitor intolerance

Background aimsAlthough calcineurin inhibitors (CNIs) have a well-established role in the prevention of graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT), their use can be limited by significant toxicities, which may result in premature treatment discontinuation. The optimal management of patients with CNI intolerance is unknown. The objective of this study was to determine the effectiveness of corticosteroids as GVHD prophylaxis for patients with CNI intolerance. MethodsThis retrospective single-center study included consecutive adult patients with hematologic malignancies who underwent myeloablative peripheral blood allogeneic HCT with anti-thymocyte globulin, CNI, and methotrexate GVHD prophylaxis in Alberta, Canada. Multivariable competing-risks regression was used to compare cumulative incidences of GVHD, relapse, and non-relapse mortality between recipients of corticosteroid versus continuous CNI prophylaxis, and multivariable Cox proportional hazards regression was applied to compare overall survival, relapse-free survival (RFS) and moderate-to-severe chronic GVHD and RFS. ResultsAmong 509 allogeneic HCT recipients, 58 (11%) patients developed CNI intolerance and were switched to corticosteroid prophylaxis at median 28 days (range 1-53) after HCT. Compared with patients who received continuous CNI prophylaxis, recipients of corticosteroid prophylaxis had significantly greater cumulative incidences of grade 2-4 acute GVHD (subhazard ratio [SHR] 1.74, 95% confidence interval [CI] 1.08–2.80, P = 0.024), grade 3–4 acute GVHD (SHR 3.22, 95% CI 1.55–6.72, P = 0.002), and GVHD-related non-relapse mortality (SHR 3.07, 95% CI 1.54–6.12, P = 0.001). There were no significant differences in moderate-to-severe chronic GVHD (SHR 0.84, 95% CI 0.43–1.63, P = 0.60) or relapse (SHR 0.92, 95% CI 0.53–1.62, P = 0.78), but corticosteroid prophylaxis was associated with significantly inferior overall survival (hazard ratio [HR] 1.77, 95% CI 1.20–2.61, P = 0.004), RFS (HR 1.54, 95% CI 1.06–2.25, P = 0.024), and chronic GVHD and RFS (HR 1.46, 95% CI 1.04–2.05, P = 0.029). ConclusionsAllogeneic HCT recipients with CNI intolerance are at increased risks of acute GVHD and poor outcomes despite institution of corticosteroid prophylaxis following premature CNI discontinuation. Alternative GVHD prophylaxis strategies are needed for this high-risk population.

Favorable outcomes following allogeneic transplantation in adults with hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is a syndrome marked by a severe hyperinflammatory state characterized by aberrant T- and natural killer-cell activity leading to prolonged hypercytokinemia and can be rapidly fatal if not diagnosed and treated early. While upfront therapy is aimed at reducing hyperinflammation and controlling possible triggers, allogeneic hematopoietic stem cell transplantation (HSCT) is indicated for primary and relapsed/refractory cases to attain sustained remission. While this has been explored extensively in the pediatric population, there are limited data on adults undergoing HSCT for HLH. We analyzed transplant outcomes in an adult HLH population in the modern era who were transplanted at Dana-Farber Cancer Institute from 2010 onwards. Patients were uniformly transplanted on a reduced intensity platform incorporating early administration of alemtuzumab with standard infectious and graft-versus-host disease (GVHD) prophylaxis. Engraftment was documented for all patients. At 3years after transplantation, overall survival (OS) was 75% (95% confidence interval [CI], 51-89) while 3-year progression-free survival (PFS) was 71% (95% CI, 46-86). The 3-year cumulative incidence of relapse was 15% (95% CI, 3.4-33). There were no isolated HLH relapses without relapse of malignancy. The cumulative incidence of nonrelapse mortality at 3 years was 15% (95% CI, 3.5-34). Infectious complications and GVHD outcomes were comparable to standard reduced-intensity conditioning (RIC) transplantation at our institute. Mixed chimerism was common but did not correlate with transplant outcomes. Our data suggest that the immune defect in HLH can be abrogated with allogeneic transplantation using a reduced intensity regimen with early administration of alemtuzumab as preconditioning, providing a potentially curative option for this difficult disease.

Dietary fat source induces gut microbiota alterations and impacts chronic murine graft- versus-host disease severity

Abstract It has been observed that a constriction of the gut microbiome occurs with high fat diet, and likewise decreased microbiome diversity is directly correlated with more severe graft-versus-host disease (GvHD) following allogeneic hematopoietic stem cell transplantation. Taken together it is plausible that not only fat content, but source of dietary fat could influence gut microbiota and GvHD outcome. We sought to address this question and developed experimental rodent diets that have the same fat content (25% kcal fat, a moderate increase in fat content from normal chow) which differ only by fat source: animal- versus plant-derived fat and found that these diets drive alterations in gut microbiota diversity. Both diets yielded similar outcomes in an acute model of GvHD, however we found that mice fed the animal-derived fat diet exhibited worse survival and outcomes in a model of chronic GvHD, than mice fed the plant-derived fat diet. These findings correlated with increased inflammation and alterations in intestinal immune cell populations following chronic GvHD induction. Collectively, our data show that diets that are equal in macronutrient content but different in fat source can promote different gut microbiomes and in turn alter intestinal homeostasis and chronic GvHD outcome. Century for the Cure - Philanthropic Fund

Effect of lethal total body irradiation on bone marrow chimerism, acute graft-versus-host disease, and tumor engraftment in mouse models: impact of different radiation techniques using low- and high-energy X-rays.

Effects of X‑ray energy levels used for myeloablative lethal total body irradiation (TBI) delivery prior to bone marrow transplantation (BMT) in preclinical mouse models were examined. In mouse models, single-fraction myeloablative TBI at alethal dose was delivered using two different X‑ray devices, either low (160 kV cabinet irradiator) or high energy (6MV linear accelerator), before semi-allogeneic hematopoietic stem-cell transplantation (HSCT) to ensure bone marrow (BM) chimerism, graft-versus-host disease (GVHD), and tumor engraftment. Recipient mice were clinically followed for 80days after bone marrow transplantation (BMT). Flow cytometry was performed to assess donor chimerism and tumor engraftment in recipient mice. Both X‑ray irradiation techniques delivered a10 Gy single fraction of TBI, presented alethal effect, and could allow near-complete early donor chimerism on day13. However, low-energy irradiation increased Tcells' alloreactivity compared to high-energy irradiation, leading to clinical consequences for GVHD and tumor engraftment outcomes. The alloreactive effect differences might be attributed to the distinction in inflammatory status of irradiated recipients at donor cell infusion (D0). Delaying donor cell administration (D1 after lethal TBI) attenuated Tcells' alloreactivity and clinical outcomes in GVHD mouse models. Different X‑ray irradiation modalities condition Tcell alloreactivity in experimental semi-allogeneic BMT. Low-energy X‑ray irradiator induces apost-TBI inflammatory burst and exacerbates alloreactive reactions. This technical and biological information should be considered in interpreting GVHD/ graft-versus-leukemia effect results in mice experimental models of BMT.

The Microbiome and Its Impact on Allogeneic Hematopoietic Cell Transplantation.

Allogeneic hematopoietic cell transplantation (alloHCT) is a standard curative therapy for a variety of benign and malignant hematological diseases. Previously, patients who underwent alloHCT were at high risk for complications with potentially life-threatening toxicities, including a variety of opportunistic infections as well as acute and chronic manifestations of graft-versus-host disease (GVHD), where the transplanted immune system can produce inflammatory damage to the patient. With recent advances, including newer conditioning regimens, advances in viral and fungal infection prophylaxis, and novel GVHD prophylactic and treatment strategies, improvements in clinical outcomes have steadily improved. One modality with great potential that has yet to be fully realized is targeting the microbiome to further improve clinical outcomes.In recent years, the intestinal microbiota, which includes bacteria, fungi, viruses, and other microbes that reside within the intestinal tract, has become established as a potent modulator of alloHCT outcomes. The composition of intestinal bacteria, in particular, has been found in large multicenter prospective studies to be strongly associated with GVHD, treatment-related mortality, and overall survival. Murine studies have demonstrated a causal relationship between intestinal microbiota injury and aggravated GVHD, and more recently, clinical interventional studies of repleting the intestinal microbiota with fecal microbiota transplantation have emerged as effective therapies for GVHD. How the composition of the intestinal bacterial microbiota, which is often highly variable in alloHCT patients, can modulate GVHD and other outcomes is not fully understood. Recent studies, however, have begun to make substantial headway, including identifying particular bacterial subsets and/or bacterial-derived metabolites that can mediate harm or benefit. Here, the authors review recent studies that have improved our mechanistic understanding of the relationship between the microbiota and alloHCT outcomes, as well as studies that are beginning to establish strategies to modulate the microbiota with the hope of optimizing clinical outcomes.